Move to ASF4 and introduce SAMD51 support. (#258)3.0.0-alpha.0

* atmel-samd: Remove ASF3. This will break builds.

* atmel-samd: Add ASF4 for the SAMD21 and SAMD51.

* Introduce the supervisor concept to facilitate porting.

The supervisor is the code which runs individual MicroPython VMs. By
splitting it out we make it more consistent and easier to find.

This also adds very basic SAMD21 and SAMD51 support using the
supervisor. Only the REPL currently works.

This begins the work for #178.

54 files changed, 10337 insertions, 0 deletions

diff --git a/atmel-samd/asf4/samd21/hal/include/hal_adc_sync.h b/atmel-samd/asf4/samd21/hal/include/hal_adc_sync.h
new file mode 100644
index 000000000..fb4604aa5
--- /dev/null
+++ b/atmel-samd/asf4/samd21/hal/include/hal_adc_sync.h
@@ -0,0 +1,287 @@
+/**
+ * \file
+ *
+ * \brief ADC functionality declaration.
+ *
+ * Copyright (C) 2014-2016 Atmel Corporation. All rights reserved.
+ *
+ * \asf_license_start
+ *
+ * \page License
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright notice,
+ *    this list of conditions and the following disclaimer.
+ *
+ * 2. Redistributions in binary form must reproduce the above copyright notice,
+ *    this list of conditions and the following disclaimer in the documentation
+ *    and/or other materials provided with the distribution.
+ *
+ * 3. The name of Atmel may not be used to endorse or promote products derived
+ *    from this software without specific prior written permission.
+ *
+ * 4. This software may only be redistributed and used in connection with an
+ *    Atmel microcontroller product.
+ *
+ * THIS SOFTWARE IS PROVIDED BY ATMEL "AS IS" AND ANY EXPRESS OR IMPLIED
+ * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
+ * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT ARE
+ * EXPRESSLY AND SPECIFICALLY DISCLAIMED. IN NO EVENT SHALL ATMEL BE LIABLE FOR
+ * ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+ * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
+ * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
+ * ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+ * POSSIBILITY OF SUCH DAMAGE.
+ *
+ * \asf_license_stop
+ *
+ */
+
+#ifndef _HAL_ADC_SYNC_H_INCLUDED
+#define _HAL_ADC_SYNC_H_INCLUDED
+
+#include <hpl_adc_sync.h>
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+/**
+ * \addtogroup doc_driver_hal_adc_sync
+ *
+ * @{
+ */
+
+/**
+ * \brief ADC descriptor
+ *
+ * The ADC descriptor forward declaration.
+ */
+struct adc_sync_descriptor;
+
+/**
+ * \brief ADC descriptor
+ */
+struct adc_sync_descriptor {
+	/** ADC device */
+	struct _adc_sync_device device;
+};
+
+/**
+ * \brief Initialize ADC
+ *
+ * This function initializes the given ADC descriptor.
+ * It checks if the given hardware is not initialized and if the given hardware
+ * is permitted to be initialized.
+ *
+ * \param[out] descr An ADC descriptor to initialize
+ * \param[in] hw     The pointer to hardware instance
+ * \param[in] func   The pointer to a set of functions pointers
+ *
+ * \return Initialization status.
+ */
+int32_t adc_sync_init(struct adc_sync_descriptor *const descr, void *const hw, void *const func);
+
+/**
+ * \brief Deinitialize ADC
+ *
+ * This function deinitializes the given ADC descriptor.
+ * It checks if the given hardware is initialized and if the given hardware is
+ * permitted to be deinitialized.
+ *
+ * \param[in] descr An ADC descriptor to deinitialize
+ *
+ * \return De-initialization status.
+ */
+int32_t adc_sync_deinit(struct adc_sync_descriptor *const descr);
+
+/**
+ * \brief Enable ADC
+ *
+ * Use this function to set the ADC peripheral to enabled state.
+ *
+ * \param[in] descr    Pointer to the ADC descriptor
+ * \param[in] channel  Channel number
+ *
+ * \return Operation status
+ *
+ */
+int32_t adc_sync_enable_channel(struct adc_sync_descriptor *const descr, const uint8_t channel);
+
+/**
+ * \brief Disable ADC
+ *
+ * Use this function to set the ADC peripheral to disabled state.
+ *
+ * \param[in] descr   Pointer to the ADC descriptor
+ * \param[in] channel Channel number
+ *
+ * \return Operation status
+ *
+ */
+int32_t adc_sync_disable_channel(struct adc_sync_descriptor *const descr, const uint8_t channel);
+
+/**
+ * \brief Read data from ADC
+ *
+ * \param[in] descr    The pointer to the ADC descriptor
+ * \param[in] channel  Channel number
+ * \param[in] buf      A buffer to read data to
+ * \param[in] length   The size of a buffer
+ *
+ * \return The number of bytes read.
+ */
+int32_t adc_sync_read_channel(struct adc_sync_descriptor *const descr, const uint8_t channel, uint8_t *const buffer,
+                              const uint16_t length);
+
+/**
+ * \brief Set ADC reference source
+ *
+ * This function sets ADC reference source.
+ *
+ * \param[in] descr     The pointer to the ADC descriptor
+ * \param[in] reference A reference source to set
+ *
+ * \return Status of the ADC reference source setting.
+ */
+int32_t adc_sync_set_reference(struct adc_sync_descriptor *const descr, const adc_reference_t reference);
+
+/**
+ * \brief Set ADC resolution
+ *
+ * This function sets ADC resolution.
+ *
+ * \param[in] descr      The pointer to the ADC descriptor
+ * \param[in] resolution A resolution to set
+ *
+ * \return Status of the ADC resolution setting.
+ */
+int32_t adc_sync_set_resolution(struct adc_sync_descriptor *const descr, const adc_resolution_t resolution);
+
+/**
+ * \brief Set ADC input source of a channel
+ *
+ * This function sets ADC positive and negative input sources.
+ *
+ * \param[in] descr     The pointer to the ADC descriptor
+ * \param[in] pos_input A positive input source to set
+ * \param[in] neg_input A negative input source to set
+ * \param[in] channel   Channel number
+ *
+ * \return Status of the ADC channels setting.
+ */
+int32_t adc_sync_set_inputs(struct adc_sync_descriptor *const descr, const adc_pos_input_t pos_input,
+                            const adc_neg_input_t neg_input, const uint8_t channel);
+
+/**
+ * \brief Set ADC conversion mode
+ *
+ * This function sets ADC conversion mode.
+ *
+ * \param[in] descr The pointer to the ADC descriptor
+ * \param[in] mode  A conversion mode to set
+ *
+ * \return Status of the ADC conversion mode setting.
+ */
+int32_t adc_sync_set_conversion_mode(struct adc_sync_descriptor *const descr, const enum adc_conversion_mode mode);
+
+/**
+ * \brief Set ADC differential mode
+ *
+ * This function sets ADC differential mode.
+ *
+ * \param[in] descr   The pointer to the ADC descriptor
+ * \param[in] channel Channel number
+ * \param[in] mode    A differential mode to set
+ *
+ * \return Status of the ADC differential mode setting.
+ */
+int32_t adc_sync_set_channel_differential_mode(struct adc_sync_descriptor *const descr, const uint8_t channel,
+                                               const enum adc_differential_mode mode);
+
+/**
+ * \brief Set ADC channel gain
+ *
+ * This function sets ADC channel gain.
+ *
+ * \param[in] descr   The pointer to the ADC descriptor
+ * \param[in] channel Channel number
+ * \param[in] gain    A gain to set
+ *
+ * \return Status of the ADC gain setting.
+ */
+int32_t adc_sync_set_channel_gain(struct adc_sync_descriptor *const descr, const uint8_t channel,
+                                  const adc_gain_t gain);
+
+/**
+ * \brief Set ADC window mode
+ *
+ * This function sets ADC window mode.
+ *
+ * \param[in] descr The pointer to the ADC descriptor
+ * \param[in] mode  A window mode to set
+ *
+ * \return Status of the ADC window mode setting.
+ */
+int32_t adc_sync_set_window_mode(struct adc_sync_descriptor *const descr, const adc_window_mode_t mode);
+
+/**
+ * \brief Set ADC thresholds
+ *
+ * This function sets ADC positive and negative thresholds.
+ *
+ * \param[in] descr         The pointer to the ADC descriptor
+ * \param[in] low_threshold A lower thresholds to set
+ * \param[in] up_threshold  An upper thresholds to set
+ *
+ * \return Status of the ADC thresholds setting.
+ */
+int32_t adc_sync_set_thresholds(struct adc_sync_descriptor *const descr, const adc_threshold_t low_threshold,
+                                const adc_threshold_t up_threshold);
+
+/**
+ * \brief Retrieve threshold state
+ *
+ * This function retrieves ADC threshold state.
+ *
+ * \param[in] descr  The pointer to the ADC descriptor
+ * \param[out] state The threshold state
+ *
+ * \return The state of ADC thresholds state retrieving.
+ */
+int32_t adc_sync_get_threshold_state(const struct adc_sync_descriptor *const descr,
+                                     adc_threshold_status_t *const           state);
+
+/**
+ * \brief Check if conversion is complete
+ *
+ * This function checks if the ADC has finished the conversion.
+ *
+ * \param[in] descr   The pointer to the ADC descriptor
+ * \param[in] channel Channel number
+ *
+ * \return The status of ADC conversion completion checking.
+ * \retval 1 The conversion is complete
+ * \retval 0 The conversion is not complete
+ */
+int32_t adc_sync_is_channel_conversion_complete(const struct adc_sync_descriptor *const descr, const uint8_t channel);
+
+/**
+ * \brief Retrieve the current driver version
+ *
+ * \return Current driver version.
+ */
+uint32_t adc_sync_get_version(void);
+/**@}*/
+
+#ifdef __cplusplus
+}
+#endif
+
+#include <hpl_missing_features.h>
+
+#endif /* _HAL_ADC_SYNC_H_INCLUDED */
diff --git a/atmel-samd/asf4/samd21/hal/include/hal_atomic.h b/atmel-samd/asf4/samd21/hal/include/hal_atomic.h
new file mode 100644
index 000000000..8a51b2a96
--- /dev/null
+++ b/atmel-samd/asf4/samd21/hal/include/hal_atomic.h
@@ -0,0 +1,137 @@
+/**
+ * \file
+ *
+ * \brief Critical sections related functionality declaration.
+ *
+ * Copyright (C) 2014 Atmel Corporation. All rights reserved.
+ *
+ * \asf_license_start
+ *
+ * \page License
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright notice,
+ *    this list of conditions and the following disclaimer.
+ *
+ * 2. Redistributions in binary form must reproduce the above copyright notice,
+ *    this list of conditions and the following disclaimer in the documentation
+ *    and/or other materials provided with the distribution.
+ *
+ * 3. The name of Atmel may not be used to endorse or promote products derived
+ *    from this software without specific prior written permission.
+ *
+ * 4. This software may only be redistributed and used in connection with an
+ *    Atmel microcontroller product.
+ *
+ * THIS SOFTWARE IS PROVIDED BY ATMEL "AS IS" AND ANY EXPRESS OR IMPLIED
+ * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
+ * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT ARE
+ * EXPRESSLY AND SPECIFICALLY DISCLAIMED. IN NO EVENT SHALL ATMEL BE LIABLE FOR
+ * ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+ * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
+ * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
+ * ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+ * POSSIBILITY OF SUCH DAMAGE.
+ *
+ * \asf_license_stop
+ *
+ */
+
+#ifndef _HAL_ATOMIC_H_INCLUDED
+#define _HAL_ATOMIC_H_INCLUDED
+
+#include <compiler.h>
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+/**
+ * \addtogroup doc_driver_hal_helper_atomic
+ *
+ *@{
+ */
+
+/**
+ * \brief Type for the register holding global interrupt enable flag
+ */
+typedef uint32_t hal_atomic_t;
+
+/**
+ * \brief Helper macro for entering critical sections
+ *
+ * This macro is recommended to be used instead of a direct call
+ * hal_enterCritical() function to enter critical
+ * sections. No semicolon is required after the macro.
+ *
+ * \section atomic_usage Usage Example
+ * \code
+ * CRITICAL_SECTION_ENTER()
+ * Critical code
+ * CRITICAL_SECTION_LEAVE()
+ * \endcode
+ */
+#define CRITICAL_SECTION_ENTER()                                                                                       \
+	{                                                                                                                  \
+		volatile hal_atomic_t __atomic;                                                                                \
+		atomic_enter_critical(&__atomic);
+
+/**
+ * \brief Helper macro for leaving critical sections
+ *
+ * This macro is recommended to be used instead of a direct call
+ * hal_leaveCritical() function to leave critical
+ * sections. No semicolon is required after the macro.
+ *
+ * \section atomic_usage Usage Example
+ * \code
+ * CRITICAL_SECTION_ENTER()
+ * Some critical code
+ * CRITICAL_SECTION_LEAVE()
+ * \endcode
+ */
+#define CRITICAL_SECTION_LEAVE()                                                                                       \
+	atomic_leave_critical(&__atomic);                                                                                  \
+	}
+
+/**
+ * \brief Disable interrupts, enter critical section
+ *
+ * Disables global interrupts. Supports nested critical sections,
+ * so that global interrupts are only re-enabled
+ * upon leaving the outermost nested critical section.
+ *
+ * \param[out] atomic The pointer to a variable to store the value of global
+ * interrupt enable flag
+ */
+void atomic_enter_critical(hal_atomic_t volatile *atomic);
+
+/**
+ * \brief Exit atomic section
+ *
+ * Enables global interrupts. Supports nested critical sections,
+ * so that global interrupts are only re-enabled
+ * upon leaving the outermost nested critical section.
+ *
+ * \param[in] atomic The pointer to a variable, which stores the latest stored
+ * value of the global interrupt enable flag
+ */
+void atomic_leave_critical(hal_atomic_t volatile *atomic);
+
+/**
+ * \brief Retrieve the current driver version
+ *
+ * \return Current driver version.
+ */
+uint32_t atomic_get_version(void);
+/**@}*/
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif /* _HAL_ATOMIC_H_INCLUDED */
diff --git a/atmel-samd/asf4/samd21/hal/include/hal_dac_sync.h b/atmel-samd/asf4/samd21/hal/include/hal_dac_sync.h
new file mode 100644
index 000000000..79c68b2cb
--- /dev/null
+++ b/atmel-samd/asf4/samd21/hal/include/hal_dac_sync.h
@@ -0,0 +1,134 @@
+/**
+ * \file
+ *
+ * \brief DAC functionality declaration.
+ *
+ * Copyright (C) 2014-2015 Atmel Corporation. All rights reserved.
+ *
+ * \asf_license_start
+ *
+ * \page License
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright notice,
+ *    this list of conditions and the following disclaimer.
+ *
+ * 2. Redistributions in binary form must reproduce the above copyright notice,
+ *    this list of conditions and the following disclaimer in the documentation
+ *    and/or other materials provided with the distribution.
+ *
+ * 3. The name of Atmel may not be used to endorse or promote products derived
+ *    from this software without specific prior written permission.
+ *
+ * 4. This software may only be redistributed and used in connection with an
+ *    Atmel microcontroller product.
+ *
+ * THIS SOFTWARE IS PROVIDED BY ATMEL "AS IS" AND ANY EXPRESS OR IMPLIED
+ * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
+ * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT ARE
+ * EXPRESSLY AND SPECIFICALLY DISCLAIMED. IN NO EVENT SHALL ATMEL BE LIABLE FOR
+ * ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+ * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
+ * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
+ * ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+ * POSSIBILITY OF SUCH DAMAGE.
+ *
+ * \asf_license_stop
+ *
+ */
+
+#ifndef HAL_SYNC_DAC_H_INCLUDED
+#define HAL_SYNC_DAC_H_INCLUDED
+
+#include <hpl_dac_sync.h>
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+/**
+ * \addtogroup doc_driver_hal_dac_sync
+ *
+ *@{
+ */
+
+/**
+ * \brief DAC synchronous descriptor.
+ *
+ * The DAC descriptor forward declaration.
+ */
+struct dac_sync_descriptor;
+
+/**
+ * \brief DAC synchronous channel descriptor.
+ *
+ */
+struct dac_sync_channel {
+	/** Pointer to buffer what to be converted */
+	uint16_t *buffer;
+	/** The length of buffer */
+	uint32_t length;
+};
+
+/**
+ * \brief DAC synchronous descriptor
+ */
+struct dac_sync_descriptor {
+	/** DAC device */
+	struct _dac_sync_device device;
+	/** DAC selected channel */
+	struct dac_sync_channel sel_ch[CHANNEL_NUM];
+};
+
+/** \brief Initialize the DAC HAL instance and hardware.
+ *  \param[out] descr A DAC descriptor to initialize
+ *  \param[in] hw The pointer to hardware instance
+ *  \return Operation status.
+ */
+int32_t dac_sync_init(struct dac_sync_descriptor *const descr, void *const hw);
+
+/** \brief Deinitialize the DAC HAL instance and hardware.
+ *  \param[in] descr Pointer to the HAL DAC descriptor
+ *  \return Operation status.
+ */
+int32_t dac_sync_deinit(struct dac_sync_descriptor *const descr);
+
+/** \brief Enable DAC channel.
+ *  \param[in] descr Pointer to the HAL DAC descriptor
+ *  \param[in] ch  Channel number
+ *  \return Operation status.
+ */
+int32_t dac_sync_enable_channel(struct dac_sync_descriptor *const descr, const uint8_t ch);
+
+/** \brief Disable DAC channel.
+ *  \param[in] descr Pointer to the HAL DAC descriptor
+ *  \param[in] ch  Channel number
+ *  \return Operation status.
+ */
+int32_t dac_sync_disable_channel(struct dac_sync_descriptor *const descr, const uint8_t ch);
+
+/** \brief DAC converts digital data to analog output.
+ *  \param[in] descr   Pointer to the HAL DAC descriptor
+ *  \param[in] ch the  Channel selected to output
+ *  \param[in] buffer  Pointer to digital data or buffer
+ *  \param[in] length  The number of elements in the buffer
+ *  \return Operation status.
+ */
+int32_t dac_sync_write(struct dac_sync_descriptor *const descr, const uint8_t ch, uint16_t *buffer, uint32_t length);
+
+/** \brief Get DAC driver version
+ *
+ *  \return Current driver version.
+ */
+uint32_t dac_sync_get_version(void);
+/**@}*/
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif /* HAL_DAC_H_INCLUDED */
diff --git a/atmel-samd/asf4/samd21/hal/include/hal_delay.h b/atmel-samd/asf4/samd21/hal/include/hal_delay.h
new file mode 100644
index 000000000..48fee826f
--- /dev/null
+++ b/atmel-samd/asf4/samd21/hal/include/hal_delay.h
@@ -0,0 +1,99 @@
+/**
+ * \file
+ *
+ * \brief HAL delay related functionality declaration.
+ *
+ * Copyright (C) 2014-2016 Atmel Corporation. All rights reserved.
+ *
+ * \asf_license_start
+ *
+ * \page License
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright notice,
+ *    this list of conditions and the following disclaimer.
+ *
+ * 2. Redistributions in binary form must reproduce the above copyright notice,
+ *    this list of conditions and the following disclaimer in the documentation
+ *    and/or other materials provided with the distribution.
+ *
+ * 3. The name of Atmel may not be used to endorse or promote products derived
+ *    from this software without specific prior written permission.
+ *
+ * 4. This software may only be redistributed and used in connection with an
+ *    Atmel microcontroller product.
+ *
+ * THIS SOFTWARE IS PROVIDED BY ATMEL "AS IS" AND ANY EXPRESS OR IMPLIED
+ * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
+ * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT ARE
+ * EXPRESSLY AND SPECIFICALLY DISCLAIMED. IN NO EVENT SHALL ATMEL BE LIABLE FOR
+ * ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+ * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
+ * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
+ * ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+ * POSSIBILITY OF SUCH DAMAGE.
+ *
+ * \asf_license_stop
+ *
+ */
+
+#include <hpl_irq.h>
+#include <hpl_reset.h>
+#include <hpl_sleep.h>
+
+#ifndef _HAL_DELAY_H_INCLUDED
+#define _HAL_DELAY_H_INCLUDED
+
+#include <compiler.h>
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+/**
+ * \addtogroup doc_driver_hal_delay Delay Driver
+ *
+ *@{
+ */
+
+/**
+ * \brief Initialize Delay driver
+ *
+ * \param[in] hw The pointer to hardware instance
+ */
+void delay_init(void *const hw);
+
+/**
+ * \brief Perform delay in us
+ *
+ * This function performs delay for the given amount of microseconds.
+ *
+ * \param[in] us The amount delay in us
+ */
+void delay_us(const uint16_t us);
+
+/**
+ * \brief Perform delay in ms
+ *
+ * This function performs delay for the given amount of milliseconds.
+ *
+ * \param[in] ms The amount delay in ms
+ */
+void delay_ms(const uint16_t ms);
+
+/**
+ * \brief Retrieve the current driver version
+ *
+ * \return Current driver version.
+ */
+uint32_t delay_get_version(void);
+
+/**@}*/
+#ifdef __cplusplus
+}
+#endif
+#endif /* _HAL_DELAY_H_INCLUDED */
diff --git a/atmel-samd/asf4/samd21/hal/include/hal_flash.h b/atmel-samd/asf4/samd21/hal/include/hal_flash.h
new file mode 100644
index 000000000..2e6286389
--- /dev/null
+++ b/atmel-samd/asf4/samd21/hal/include/hal_flash.h
@@ -0,0 +1,219 @@
+/**
+ * \file
+ *
+ * \brief Flash related functionality declaration.
+ *
+ * Copyright (C) 2015 Atmel Corporation. All rights reserved.
+ *
+ * \asf_license_start
+ *
+ * \page License
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright notice,
+ *    this list of conditions and the following disclaimer.
+ *
+ * 2. Redistributions in binary form must reproduce the above copyright notice,
+ *    this list of conditions and the following disclaimer in the documentation
+ *    and/or other materials provided with the distribution.
+ *
+ * 3. The name of Atmel may not be used to endorse or promote products derived
+ *    from this software without specific prior written permission.
+ *
+ * 4. This software may only be redistributed and used in connection with an
+ *    Atmel microcontroller product.
+ *
+ * THIS SOFTWARE IS PROVIDED BY ATMEL "AS IS" AND ANY EXPRESS OR IMPLIED
+ * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
+ * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT ARE
+ * EXPRESSLY AND SPECIFICALLY DISCLAIMED. IN NO EVENT SHALL ATMEL BE LIABLE FOR
+ * ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+ * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
+ * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
+ * ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+ * POSSIBILITY OF SUCH DAMAGE.
+ *
+ * \asf_license_stop
+ *
+ */
+
+#ifndef _HAL_FLASH_H_INCLUDED
+#define _HAL_FLASH_H_INCLUDED
+
+#include <hpl_flash.h>
+
+/**
+ * \addtogroup doc_driver_hal_flash
+ *
+ * @{
+ */
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+/* Forward declaration of flash_descriptor. */
+struct flash_descriptor;
+
+/** The callback types */
+enum flash_cb_type {
+	/** Callback type for ready to accept a new command */
+	FLASH_CB_READY,
+	/** Callback type for error */
+	FLASH_CB_ERROR,
+	FLASH_CB_N
+};
+
+/** \brief Prototype of callback on FLASH
+ *
+ */
+typedef void (*flash_cb_t)(struct flash_descriptor *const descr);
+
+/** \brief FLASH HAL callbacks
+ *
+ */
+struct flash_callbacks {
+	/** Callback invoked when ready to accept a new command */
+	flash_cb_t cb_ready;
+	/** Callback invoked when error occurs */
+	flash_cb_t cb_error;
+};
+
+/** \brief FLASH HAL driver struct for asynchronous access
+ */
+struct flash_descriptor {
+	/** Pointer to FLASH device instance */
+	struct _flash_device dev;
+	/** Callbacks for asynchronous transfer */
+	struct flash_callbacks callbacks;
+};
+
+/** \brief Initialize the FLASH HAL instance and hardware for callback mode
+ *
+ *  Initialize FLASH HAL with interrupt mode (uses callbacks).
+ *
+ *  \param[in, out] flash Pointer to the HAL FLASH instance.
+ *  \param[in] hw Pointer to the hardware base.
+ *  \return Initialize status.
+ */
+int32_t flash_init(struct flash_descriptor *flash, void *const hw);
+
+/** \brief Deinitialize the FLASH HAL instance
+ *
+ *  Abort transfer, disable and reset FLASH, and deinitialize software.
+ *
+ *  \param[in, out] flash Pointer to the HAL FLASH instance.
+ *  \return Deinitialze status.
+ */
+int32_t flash_deinit(struct flash_descriptor *flash);
+
+/** \brief Writes a number of bytes to a page in the internal Flash
+ *
+ *  \param[in, out] flash Pointer to the HAL FLASH instance.
+ *  \param[in]  dst_addr  Destination bytes address to write into flash
+ *  \param[in]  buffer    Pointer to a buffer where the content
+ *                        will be written to the flash
+ *  \param[in]  length    Number of bytes to write
+ *  \return Write status.
+ */
+int32_t flash_write(struct flash_descriptor *flash, uint32_t dst_addr, uint8_t *buffer, uint32_t length);
+
+/** \brief Appends a number of bytes to a page in the internal Flash
+ *
+ *  This functions never erases the flash before writing.
+ *
+ *  \param[in, out] flash Pointer to the HAL FLASH instance.
+ *  \param[in]  dst_addr  Destination bytes address to write to flash
+ *  \param[in]  buffer    Pointer to a buffer with data to write to flash
+ *  \param[in]  length    Number of bytes to append
+ *  \return Append status.
+ */
+int32_t flash_append(struct flash_descriptor *flash, uint32_t dst_addr, uint8_t *buffer, uint32_t length);
+
+/** \brief Reads a number of bytes to a page in the internal Flash
+ *
+ *  \param[in, out] flash Pointer to the HAL FLASH instance.
+ *  \param[in]  src_addr  Source bytes address to read from flash
+ *  \param[out] buffer    Pointer to a buffer where the content
+ *                        of the read pages will be stored
+ *  \param[in]  length    Number of bytes to read
+ *  \return Read status.
+ */
+int32_t flash_read(struct flash_descriptor *flash, uint32_t src_addr, uint8_t *buffer, uint32_t length);
+
+/** \brief Register a function as FLASH transfer completion callback
+ *
+ *  \param[in, out] flash Pointer to the HAL FLASH instance.
+ *  \param[in] type Callback type (\ref flash_cb_type).
+ *  \param[in] func Pointer to callback function.
+ *  \retval 0 Success
+ *  \retval -1 Error
+ */
+int32_t flash_register_callback(struct flash_descriptor *flash, const enum flash_cb_type type, flash_cb_t func);
+
+/** \brief Execute lock in the internal flash
+ *
+ *  \param[in, out] flash Pointer to the HAL FLASH instance.
+ *  \param[in]  dst_addr  Destination bytes address aligned with page
+ *                        start to be locked
+ *  \param[in]  page_nums Number of pages to be locked
+ *
+ *  \return Real locked numbers of pages.
+ */
+int32_t flash_lock(struct flash_descriptor *flash, const uint32_t dst_addr, const uint32_t page_nums);
+
+/** \brief Execute unlock in the internal flash
+ *
+ *  \param[in, out] flash Pointer to the HAL FLASH instance.
+ *  \param[in]  dst_addr  Destination bytes address aligned with page
+ *                        start to be unlocked
+ *  \param[in]  page_nums Number of pages to be unlocked
+ *
+ *  \return Real unlocked numbers of pages.
+ */
+int32_t flash_unlock(struct flash_descriptor *flash, const uint32_t dst_addr, const uint32_t page_nums);
+
+/** \brief Execute erase in the internal flash
+ *
+ *  \param[in, out] flash Pointer to the HAL FLASH instance.
+ *  \param[in]  dst_addr  Destination bytes address aligned with page
+ *                        start to be erased
+ *  \param[in]  page_nums Number of pages to be erased
+ *  \retval 0 Success
+ *  \retval -1 Error
+ */
+int32_t flash_erase(struct flash_descriptor *flash, const uint32_t dst_addr, const uint32_t page_nums);
+
+/**
+ * \brief Get the flash page size
+ *
+ * \param[in, out] flash Pointer to the HAL FLASH instance
+ *
+ * \return The flash page size
+ */
+uint32_t flash_get_page_size(struct flash_descriptor *flash);
+
+/**
+ * \brief Get the number of flash page
+ *
+ * \param[in, out] flash Pointer to the HAL FLASH instance.
+ *
+ * \return The flash total page numbers
+ */
+uint32_t flash_get_total_pages(struct flash_descriptor *flash);
+
+/** \brief Retrieve the current driver version
+ *
+ *  \return Current driver version.
+ */
+uint32_t flash_get_version(void);
+
+#ifdef __cplusplus
+}
+#endif
+/**@}*/
+#endif /* ifndef _HAL_FLASH_H_INCLUDED */
diff --git a/atmel-samd/asf4/samd21/hal/include/hal_gpio.h b/atmel-samd/asf4/samd21/hal/include/hal_gpio.h
new file mode 100644
index 000000000..f0e8af8d7
--- /dev/null
+++ b/atmel-samd/asf4/samd21/hal/include/hal_gpio.h
@@ -0,0 +1,212 @@
+/**
+ * \file
+ *
+ * \brief Port
+ *
+ * Copyright (C) 2014 Atmel Corporation. All rights reserved.
+ *
+ * \asf_license_start
+ *
+ * \page License
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright notice,
+ *    this list of conditions and the following disclaimer.
+ *
+ * 2. Redistributions in binary form must reproduce the above copyright notice,
+ *    this list of conditions and the following disclaimer in the documentation
+ *    and/or other materials provided with the distribution.
+ *
+ * 3. The name of Atmel may not be used to endorse or promote products derived
+ *    from this software without specific prior written permission.
+ *
+ * 4. This software may only be redistributed and used in connection with an
+ *    Atmel microcontroller product.
+ *
+ * THIS SOFTWARE IS PROVIDED BY ATMEL "AS IS" AND ANY EXPRESS OR IMPLIED
+ * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
+ * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT ARE
+ * EXPRESSLY AND SPECIFICALLY DISCLAIMED. IN NO EVENT SHALL ATMEL BE LIABLE FOR
+ * ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+ * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
+ * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
+ * ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+ * POSSIBILITY OF SUCH DAMAGE.
+ *
+ * \asf_license_stop
+ */
+#ifndef _HAL_GPIO_INCLUDED_
+#define _HAL_GPIO_INCLUDED_
+
+#include <hpl_gpio.h>
+#include <utils_assert.h>
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+/**
+ * \brief Set gpio pull mode
+ *
+ * Set pin pull mode, non existing pull modes throws an fatal assert
+ *
+ * \param[in] pin       The pin number for device
+ * \param[in] pull_mode GPIO_PULL_DOWN = Pull pin high with internal
+ *                      resistor
+ *                      GPIO_PULL_UP   = Pull pin low with internal resistor
+ *                      GPIO_PULL_OFF  = Disable pin pull mode
+ */
+static inline void gpio_set_pin_pull_mode(const uint8_t pin, const enum gpio_pull_mode pull_mode)
+{
+	_gpio_set_pin_pull_mode((enum gpio_port)GPIO_PORT(pin), pin & 0x1F, pull_mode);
+}
+
+/**
+ * \brief Set pin function
+ *
+ * Select which function a pin will be used for
+ *
+ * \param[in] pin       The pin number for device
+ * \param[in] function  The pin function is given by a 32-bit wide bitfield
+ *                      found in the header files for the device
+ *
+ */
+static inline void gpio_set_pin_function(const uint32_t pin, uint32_t function)
+{
+	_gpio_set_pin_function(pin, function);
+}
+
+/**
+ * \brief Set port data direction
+ *
+ * Select if the pin data direction is input, output or disabled.
+ * If disabled state is not possible, this function throws an assert.
+ *
+ * \param[in] port      Ports are grouped into groups of maximum 32 pins,
+ *                      GPIO_PORTA = group 0, GPIO_PORTB = group 1, etc
+ * \param[in] mask      Bit mask where 1 means apply direction setting to the
+ *                      corresponding pin
+ * \param[in] direction GPIO_DIRECTION_IN  = Data direction in
+ *                      GPIO_DIRECTION_OUT = Data direction out
+ *                      GPIO_DIRECTION_OFF = Disables the pin
+ *                      (low power state)
+ */
+static inline void gpio_set_port_direction(const enum gpio_port port, const uint32_t mask,
+                                           const enum gpio_direction direction)
+{
+	_gpio_set_direction(port, mask, direction);
+}
+
+/**
+ * \brief Set gpio data direction
+ *
+ * Select if the pin data direction is input, output or disabled.
+ * If disabled state is not possible, this function throws an assert.
+ *
+ * \param[in] pin       The pin number for device
+ * \param[in] direction GPIO_DIRECTION_IN  = Data direction in
+ *                      GPIO_DIRECTION_OUT = Data direction out
+ *                      GPIO_DIRECTION_OFF = Disables the pin
+ *                      (low power state)
+ */
+static inline void gpio_set_pin_direction(const uint8_t pin, const enum gpio_direction direction)
+{
+	_gpio_set_direction((enum gpio_port)GPIO_PORT(pin), 1U << GPIO_PIN(pin), direction);
+}
+
+/**
+ * \brief Set port level
+ *
+ * Sets output level on the pins defined by the bit mask
+ *
+ * \param[in] port  Ports are grouped into groups of maximum 32 pins,
+ *                  GPIO_PORTA = group 0, GPIO_PORTB = group 1, etc
+ * \param[in] mask  Bit mask where 1 means apply port level to the corresponding
+ *                  pin
+ * \param[in] level true  = Pin levels set to "high" state
+ *                  false = Pin levels set to "low" state
+ */
+static inline void gpio_set_port_level(const enum gpio_port port, const uint32_t mask, const bool level)
+{
+	_gpio_set_level(port, mask, level);
+}
+
+/**
+ * \brief Set gpio level
+ *
+ * Sets output level on a pin
+ *
+ * \param[in] pin       The pin number for device
+ * \param[in] level true  = Pin level set to "high" state
+ *                  false = Pin level set to "low" state
+ */
+static inline void gpio_set_pin_level(const uint8_t pin, const bool level)
+{
+	_gpio_set_level((enum gpio_port)GPIO_PORT(pin), 1U << GPIO_PIN(pin), level);
+}
+
+/**
+ * \brief Toggle out level on pins
+ *
+ * Toggle the pin levels on pins defined by bit mask
+ *
+ * \param[in] port  Ports are grouped into groups of maximum 32 pins,
+ *                  GPIO_PORTA = group 0, GPIO_PORTB = group 1, etc
+ * \param[in] mask  Bit mask where 1 means toggle pin level to the corresponding
+ *                  pin
+ */
+static inline void gpio_toggle_port_level(const enum gpio_port port, const uint32_t mask)
+{
+	_gpio_toggle_level(port, mask);
+}
+
+/**
+ * \brief Toggle output level on pin
+ *
+ * Toggle the pin levels on pins defined by bit mask
+ *
+ * \param[in] pin       The pin number for device
+ */
+static inline void gpio_toggle_pin_level(const uint8_t pin)
+{
+	_gpio_toggle_level((enum gpio_port)GPIO_PORT(pin), 1U << GPIO_PIN(pin));
+}
+
+/**
+ * \brief Get input level on pins
+ *
+ * Read the input level on pins connected to a port
+ *
+ * \param[in] port  Ports are grouped into groups of maximum 32 pins,
+ *                  GPIO_PORTA = group 0, GPIO_PORTB = group 1, etc
+ */
+static inline uint32_t gpio_get_port_level(const enum gpio_port port)
+{
+	return _gpio_get_level(port);
+}
+
+/**
+ * \brief Get level on pin
+ *
+ * Reads the level on pins connected to a port
+ *
+ * \param[in] pin       The pin number for device
+ */
+static inline bool gpio_get_pin_level(const uint8_t pin)
+{
+	return (bool)(_gpio_get_level((enum gpio_port)GPIO_PORT(pin)) & (0x01U << GPIO_PIN(pin)));
+}
+/**
+ * \brief Get current driver version
+ */
+uint32_t gpio_get_version(void);
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif
diff --git a/atmel-samd/asf4/samd21/hal/include/hal_i2c_m_sync.h b/atmel-samd/asf4/samd21/hal/include/hal_i2c_m_sync.h
new file mode 100644
index 000000000..65741831a
--- /dev/null
+++ b/atmel-samd/asf4/samd21/hal/include/hal_i2c_m_sync.h
@@ -0,0 +1,254 @@
+/**
+ * \file
+ *
+ * \brief Sync I2C Hardware Abstraction Layer(HAL) declaration.
+ *
+ * Copyright (C) 2014 Atmel Corporation. All rights reserved.
+ *
+ * \asf_license_start
+ *
+ * \page License
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright notice,
+ *    this list of conditions and the following disclaimer.
+ *
+ * 2. Redistributions in binary form must reproduce the above copyright notice,
+ *    this list of conditions and the following disclaimer in the documentation
+ *    and/or other materials provided with the distribution.
+ *
+ * 3. The name of Atmel may not be used to endorse or promote products derived
+ *    from this software without specific prior written permission.
+ *
+ * 4. This software may only be redistributed and used in connection with an
+ *    Atmel microcontroller product.
+ *
+ * THIS SOFTWARE IS PROVIDED BY ATMEL "AS IS" AND ANY EXPRESS OR IMPLIED
+ * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
+ * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT ARE
+ * EXPRESSLY AND SPECIFICALLY DISCLAIMED. IN NO EVENT SHALL ATMEL BE LIABLE FOR
+ * ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+ * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
+ * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
+ * ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+ * POSSIBILITY OF SUCH DAMAGE.
+ *
+ * \asf_license_stop
+ *
+ */
+
+#ifndef _HAL_I2C_M_SYNC_H_INCLUDED
+#define _HAL_I2C_M_SYNC_H_INCLUDED
+
+#include <hpl_i2c_m_sync.h>
+#include <hal_io.h>
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+/**
+ * \addtogroup doc_driver_hal_i2c_master_sync
+ *
+ * @{
+ */
+
+#define I2C_M_MAX_RETRY 1
+
+/**
+ * \brief I2C descriptor structure, embed i2c_device & i2c_interface
+ */
+struct i2c_m_sync_desc {
+	struct _i2c_m_sync_device device;
+	struct io_descriptor      io;
+	uint16_t                  slave_addr;
+};
+
+/**
+ * \brief Initialize synchronous I2C interface
+ *
+ * This function initializes the given I/O descriptor to be used as a
+ * synchronous I2C interface descriptor.
+ * It checks if the given hardware is not initialized and if the given hardware
+ * is permitted to be initialized.
+ *
+ * \param[in] i2c An I2C descriptor, which is used to communicate through I2C
+ * \param[in] hw The pointer to hardware instance
+ *
+ * \return Initialization status.
+ * \retval -1 The passed parameters were invalid or the interface is already initialized
+ * \retval 0 The initialization is completed successfully
+ */
+int32_t i2c_m_sync_init(struct i2c_m_sync_desc *i2c, void *hw);
+
+/**
+ * \brief Deinitialize I2C interface
+ *
+ * This function deinitializes the given I/O descriptor.
+ * It checks if the given hardware is initialized and if the given hardware is permitted to be deinitialized.
+ *
+ * \param[in] i2c An I2C descriptor, which is used to communicate through I2C
+ *
+ * \return Uninitialization status.
+ * \retval -1 The passed parameters were invalid or the interface is already deinitialized
+ * \retval 0 The de-initialization is completed successfully
+ */
+int32_t i2c_m_sync_deinit(struct i2c_m_sync_desc *i2c);
+
+/**
+ * \brief Set the slave device address
+ *
+ * This function sets the next transfer target slave I2C device address.
+ * It takes no effect to any already started access.
+ *
+ * \param[in] i2c An I2C descriptor, which is used to communicate through I2C
+ * \param[in] addr The slave address to access
+ * \param[in] addr_len The slave address length, can be I2C_M_TEN or I2C_M_SEVEN
+ *
+ * \return Masked slave address. The mask is a maximum 10-bit address, and 10th
+ *         bit is set if a 10-bit address is used
+ */
+int32_t i2c_m_sync_set_slaveaddr(struct i2c_m_sync_desc *i2c, int16_t addr, int32_t addr_len);
+
+/**
+ * \brief Set baudrate
+ *
+ * This function sets the I2C device to the specified baudrate.
+ * It only takes effect when the hardware is disabled.
+ *
+ * \param[in] i2c An I2C descriptor, which is used to communicate through I2C
+ * \param[in] clkrate Unused parameter. Should always be 0
+ * \param[in] baudrate The baudrate value set to master
+ *
+ * \return Whether successfully set the baudrate
+ * \retval -1 The passed parameters were invalid or the device is already enabled
+ * \retval 0 The baudrate set is completed successfully
+ */
+int32_t i2c_m_sync_set_baudrate(struct i2c_m_sync_desc *i2c, uint32_t clkrate, uint32_t baudrate);
+
+/**
+ * \brief Sync version of enable hardware
+ *
+ * This function enables the I2C device, and then waits for this enabling operation to be done
+ *
+ * \param[in] i2c An I2C descriptor, which is used to communicate through I2C
+ *
+ * \return Whether successfully enable the device
+ * \retval -1 The passed parameters were invalid or the device enable failed
+ * \retval 0 The hardware enabling is completed successfully
+ */
+int32_t i2c_m_sync_enable(struct i2c_m_sync_desc *i2c);
+
+/**
+ * \brief Sync version of disable hardware
+ *
+ * This function disables the I2C device and then waits for this disabling operation to be done
+ *
+ * \param[in] i2c An I2C descriptor, which is used to communicate through I2C
+ *
+ * \return Whether successfully disable the device
+ * \retval -1 The passed parameters were invalid or the device disable failed
+ * \retval 0 The hardware disabling is completed successfully
+ */
+int32_t i2c_m_sync_disable(struct i2c_m_sync_desc *i2c);
+
+/**
+ * \brief Sync version of write command to I2C slave
+ *
+ * This function will write the value to a specified register in the I2C slave device and
+ * then wait for this operation to be done.
+ *
+ * The sequence of this routine is
+ * sta->address(write)->ack->reg address->ack->resta->address(write)->ack->reg value->nack->stt
+ *
+ * \param[in] i2c An I2C descriptor, which is used to communicate through I2C
+ * \param[in] reg The internal address/register of the I2C slave device
+ * \param[in] buffer The buffer holding data to write to the I2C slave device
+ * \param[in] length The length (in bytes) to write to the I2C slave device
+ *
+ * \return Whether successfully write to the device
+ * \retval <0 The passed parameters were invalid or write fail
+ * \retval 0 Writing to register is completed successfully
+ */
+int32_t i2c_m_sync_cmd_write(struct i2c_m_sync_desc *i2c, uint8_t reg, uint8_t *buffer, uint8_t length);
+
+/**
+ * \brief Sync version of read register value from I2C slave
+ *
+ * This function will read a byte value from a specified register in the I2C slave device and
+ * then wait for this operation to be done.
+ *
+ * The sequence of this routine is
+ * sta->address(write)->ack->reg address->ack->resta->address(read)->ack->reg value->nack->stt
+ *
+ * \param[in] i2c An I2C descriptor, which is used to communicate through I2C
+ * \param[in] reg The internal address/register of the I2C slave device
+ * \param[in] buffer The buffer to hold the read data from the I2C slave device
+ * \param[in] length The length (in bytes) to read from the I2C slave device
+ *
+ * \return Whether successfully read from the device
+ * \retval <0 The passed parameters were invalid or read fail
+ * \retval 0 Reading from register is completed successfully
+ */
+int32_t i2c_m_sync_cmd_read(struct i2c_m_sync_desc *i2c, uint8_t reg, uint8_t *buffer, uint8_t length);
+
+/**
+ * \brief Sync version of transfer message to/from the I2C slave
+ *
+ * This function will transfer a message between the I2C slave and the master. This function will wait for the operation
+ * to be done.
+ *
+ * \param[in] i2c An I2C descriptor, which is used to communicate through I2C
+ * \param[in] msg  An i2c_m_msg struct
+ *
+ * \return The status of the operation
+ * \retval 0 Operation completed successfully
+ * \retval <0 Operation failed
+ */
+int32_t i2c_m_sync_transfer(struct i2c_m_sync_desc *const i2c, struct _i2c_m_msg *msg);
+
+/**
+ * \brief Sync version of send stop condition on the i2c bus
+ *
+ * This function will create a stop condition on the i2c bus to release the bus
+ *
+ * \param[in] i2c An I2C descriptor, which is used to communicate through I2C
+ *
+ * \return The status of the operation
+ * \retval 0 Operation completed successfully
+ * \retval <0 Operation failed
+ */
+int32_t i2c_m_sync_send_stop(struct i2c_m_sync_desc *const i2c);
+
+/**
+ * \brief Return I/O descriptor for this I2C instance
+ *
+ * This function will return a I/O instance for this I2C driver instance
+ *
+ * \param[in] i2c_m_sync_desc An I2C descriptor, which is used to communicate through I2C
+ * \param[in] io_descriptor A pointer to an I/O descriptor pointer type
+ *
+ * \return Error code
+ * \retval 0 No error detected
+ * \retval <0 Error code
+ */
+int32_t i2c_m_sync_get_io_descriptor(struct i2c_m_sync_desc *const i2c, struct io_descriptor **io);
+
+/**
+ * \brief Retrieve the current driver version
+ *
+ * \return Current driver version.
+ */
+uint32_t i2c_m_sync_get_version(void);
+
+/**@}*/
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif
diff --git a/atmel-samd/asf4/samd21/hal/include/hal_init.h b/atmel-samd/asf4/samd21/hal/include/hal_init.h
new file mode 100644
index 000000000..a970943eb
--- /dev/null
+++ b/atmel-samd/asf4/samd21/hal/include/hal_init.h
@@ -0,0 +1,82 @@
+/**
+ * \file
+ *
+ * \brief HAL initialization related functionality declaration.
+ *
+ * Copyright (C) 2014 Atmel Corporation. All rights reserved.
+ *
+ * \asf_license_start
+ *
+ * \page License
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright notice,
+ *    this list of conditions and the following disclaimer.
+ *
+ * 2. Redistributions in binary form must reproduce the above copyright notice,
+ *    this list of conditions and the following disclaimer in the documentation
+ *    and/or other materials provided with the distribution.
+ *
+ * 3. The name of Atmel may not be used to endorse or promote products derived
+ *    from this software without specific prior written permission.
+ *
+ * 4. This software may only be redistributed and used in connection with an
+ *    Atmel microcontroller product.
+ *
+ * THIS SOFTWARE IS PROVIDED BY ATMEL "AS IS" AND ANY EXPRESS OR IMPLIED
+ * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
+ * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT ARE
+ * EXPRESSLY AND SPECIFICALLY DISCLAIMED. IN NO EVENT SHALL ATMEL BE LIABLE FOR
+ * ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+ * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
+ * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
+ * ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+ * POSSIBILITY OF SUCH DAMAGE.
+ *
+ * \asf_license_stop
+ *
+ */
+
+#ifndef _HAL_INIT_H_INCLUDED
+#define _HAL_INIT_H_INCLUDED
+
+#include <hpl_init.h>
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+/**
+ * \addtogroup doc_driver_hal_helper_init Init Driver
+ *
+ *@{
+ */
+
+/**
+ * \brief Initialize the hardware abstraction layer
+ *
+ * This function calls the various initialization functions.
+ * Currently the following initialization functions are supported:
+ *  - System clock initialization
+ */
+static inline void init_mcu(void)
+{
+	_init_chip();
+}
+
+/**
+ * \brief Retrieve the current driver version
+ *
+ * \return Current driver version.
+ */
+uint32_t init_get_version(void);
+
+/**@}*/
+#ifdef __cplusplus
+}
+#endif
+#endif /* _HAL_INIT_H_INCLUDED */
diff --git a/atmel-samd/asf4/samd21/hal/include/hal_io.h b/atmel-samd/asf4/samd21/hal/include/hal_io.h
new file mode 100644
index 000000000..e8005e3db
--- /dev/null
+++ b/atmel-samd/asf4/samd21/hal/include/hal_io.h
@@ -0,0 +1,120 @@
+/**
+ * \file
+ *
+ * \brief I/O related functionality declaration.
+ *
+ * Copyright (C) 2014 - 2016 Atmel Corporation. All rights reserved.
+ *
+ * \asf_license_start
+ *
+ * \page License
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright notice,
+ *    this list of conditions and the following disclaimer.
+ *
+ * 2. Redistributions in binary form must reproduce the above copyright notice,
+ *    this list of conditions and the following disclaimer in the documentation
+ *    and/or other materials provided with the distribution.
+ *
+ * 3. The name of Atmel may not be used to endorse or promote products derived
+ *    from this software without specific prior written permission.
+ *
+ * 4. This software may only be redistributed and used in connection with an
+ *    Atmel microcontroller product.
+ *
+ * THIS SOFTWARE IS PROVIDED BY ATMEL "AS IS" AND ANY EXPRESS OR IMPLIED
+ * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
+ * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT ARE
+ * EXPRESSLY AND SPECIFICALLY DISCLAIMED. IN NO EVENT SHALL ATMEL BE LIABLE FOR
+ * ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+ * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
+ * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
+ * ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+ * POSSIBILITY OF SUCH DAMAGE.
+ *
+ * \asf_license_stop
+ *
+ */
+
+#ifndef _HAL_IO_INCLUDED
+#define _HAL_IO_INCLUDED
+
+/**
+ * \addtogroup doc_driver_hal_helper_io I/O Driver
+ *
+ *@{
+ */
+
+#include <compiler.h>
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+/**
+ * \brief I/O descriptor
+ *
+ * The I/O descriptor forward declaration.
+ */
+struct io_descriptor;
+
+/**
+ * \brief I/O write function pointer type
+ */
+typedef int32_t (*io_write_t)(struct io_descriptor *const io_descr, const uint8_t *const buf, const uint16_t length);
+
+/**
+ * \brief I/O read function pointer type
+ */
+typedef int32_t (*io_read_t)(struct io_descriptor *const io_descr, uint8_t *const buf, const uint16_t length);
+
+/**
+ * \brief I/O descriptor
+ */
+struct io_descriptor {
+	io_write_t write; /*! The write function pointer. */
+	io_read_t  read;  /*! The read function pointer. */
+};
+
+/**
+ * \brief I/O write interface
+ *
+ * This function writes up to \p length of bytes to a given I/O descriptor.
+ * It returns the number of bytes actually write.
+ *
+ * \param[in] descr  An I/O descriptor to write
+ * \param[in] buf    The buffer pointer to story the write data
+ * \param[in] length The number of bytes to write
+ *
+ * \return The number of bytes written
+ */
+int32_t io_write(struct io_descriptor *const io_descr, const uint8_t *const buf, const uint16_t length);
+
+/**
+ * \brief I/O read interface
+ *
+ * This function reads up to \p length bytes from a given I/O descriptor, and
+ * stores it in the buffer pointed to by \p buf. It returns the number of bytes
+ * actually read.
+ *
+ * \param[in] descr  An I/O descriptor to read
+ * \param[in] buf    The buffer pointer to story the read data
+ * \param[in] length The number of bytes to read
+ *
+ * \return The number of bytes actually read. This number can be less than the
+ *         requested length. E.g., in a driver that uses ring buffer for
+ *         reception, it may depend on the availability of data in the
+ *         ring buffer.
+ */
+int32_t io_read(struct io_descriptor *const io_descr, uint8_t *const buf, const uint16_t length);
+
+#ifdef __cplusplus
+}
+#endif
+/**@}*/
+#endif /* _HAL_IO_INCLUDED */
diff --git a/atmel-samd/asf4/samd21/hal/include/hal_pwm.h b/atmel-samd/asf4/samd21/hal/include/hal_pwm.h
new file mode 100644
index 000000000..29efc4bc4
--- /dev/null
+++ b/atmel-samd/asf4/samd21/hal/include/hal_pwm.h
@@ -0,0 +1,161 @@
+/**
+ * \file
+ *
+ * \brief PWM functionality declaration.
+ *
+ * Copyright (C) 2014-2016 Atmel Corporation. All rights reserved.
+ *
+ * \asf_license_start
+ *
+ * \page License
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright notice,
+ *    this list of conditions and the following disclaimer.
+ *
+ * 2. Redistributions in binary form must reproduce the above copyright notice,
+ *    this list of conditions and the following disclaimer in the documentation
+ *    and/or other materials provided with the distribution.
+ *
+ * 3. The name of Atmel may not be used to endorse or promote products derived
+ *    from this software without specific prior written permission.
+ *
+ * 4. This software may only be redistributed and used in connection with an
+ *    Atmel microcontroller product.
+ *
+ * THIS SOFTWARE IS PROVIDED BY ATMEL "AS IS" AND ANY EXPRESS OR IMPLIED
+ * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
+ * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT ARE
+ * EXPRESSLY AND SPECIFICALLY DISCLAIMED. IN NO EVENT SHALL ATMEL BE LIABLE FOR
+ * ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+ * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
+ * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
+ * ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+ * POSSIBILITY OF SUCH DAMAGE.
+ *
+ * \asf_license_stop
+ *
+ */
+
+#ifndef HAL_PWM_H_INCLUDED
+#define HAL_PWM_H_INCLUDED
+
+#include <hpl_pwm.h>
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+/**
+ * \addtogroup doc_driver_hal_pwm_async
+ *
+ *@{
+ */
+
+/**
+ * \brief PWM descriptor
+ *
+ * The PWM descriptor forward declaration.
+ */
+struct pwm_descriptor;
+
+/**
+ * \brief PWM callback type
+ */
+typedef void (*pwm_cb_t)(const struct pwm_descriptor *const descr);
+
+/**
+ * \brief PWM callback types
+ */
+enum pwm_callback_type { PWM_PERIOD_CB, PWM_ERROR_CB };
+
+/**
+ * \brief PWM callbacks
+ */
+struct pwm_callbacks {
+	pwm_cb_t period;
+	pwm_cb_t error;
+};
+
+/** \brief PWM descriptor
+ */
+struct pwm_descriptor {
+	/** PWM device */
+	struct _pwm_device device;
+	/** PWM callback structure */
+	struct pwm_callbacks pwm_cb;
+};
+
+/** \brief Initialize the PWM HAL instance and hardware
+ *
+ *  \param[in] descr Pointer to the HAL PWM descriptor
+ *  \param[in] hw The pointer to hardware instance
+ *  \param[in] func The pointer to a set of functions pointers
+ *
+ *  \return Operation status.
+ */
+int32_t pwm_init(struct pwm_descriptor *const descr, void *const hw, struct _pwm_hpl_interface *const func);
+
+/** \brief Deinitialize the PWM HAL instance and hardware
+ *
+ *  \param[in] descr Pointer to the HAL PWM descriptor
+ *
+ *  \return Operation status.
+ */
+int32_t pwm_deinit(struct pwm_descriptor *const descr);
+
+/** \brief PWM output start
+ *
+ *  \param[in] descr Pointer to the HAL PWM descriptor
+ *
+ *  \return Operation status.
+ */
+int32_t pwm_enable(struct pwm_descriptor *const descr);
+
+/** \brief PWM output stop
+ *
+ *  \param[in] descr Pointer to the HAL PWM descriptor
+ *
+ *  \return Operation status.
+ */
+int32_t pwm_disable(struct pwm_descriptor *const descr);
+
+/** \brief Register PWM callback
+ *
+ *  \param[in] descr Pointer to the HAL PWM descriptor
+ *  \param[in] type Callback type
+ *  \param[in] cb A callback function, passing NULL de-registers callback
+ *
+ *  \return Operation status.
+ *  \retval 0 Success
+ *  \retval -1 Error
+ */
+int32_t pwm_register_callback(struct pwm_descriptor *const descr, enum pwm_callback_type type, pwm_cb_t cb);
+
+/** \brief Change PWM parameter
+ *
+ *  \param[in] descr Pointer to the HAL PWM descriptor
+ *  \param[in] period Total period of one PWM cycle
+ *  \param[in] duty_cycle Period of PWM first half during one cycle
+ *
+ *  \return Operation status.
+ */
+int32_t pwm_set_parameters(struct pwm_descriptor *const descr, const pwm_period_t period,
+                           const pwm_period_t duty_cycle);
+
+/** \brief Get PWM driver version
+ *
+ *  \return Current driver version.
+ */
+uint32_t pwm_get_version(void);
+/**@}*/
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif /* HAL_PWM;_H_INCLUDED */
diff --git a/atmel-samd/asf4/samd21/hal/include/hal_sleep.h b/atmel-samd/asf4/samd21/hal/include/hal_sleep.h
new file mode 100644
index 000000000..0a11856b1
--- /dev/null
+++ b/atmel-samd/asf4/samd21/hal/include/hal_sleep.h
@@ -0,0 +1,84 @@
+/**
+ * \file
+ *
+ * \brief Sleep related functionality declaration.
+ *
+ * Copyright (C) 2014 Atmel Corporation. All rights reserved.
+ *
+ * \asf_license_start
+ *
+ * \page License
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright notice,
+ *    this list of conditions and the following disclaimer.
+ *
+ * 2. Redistributions in binary form must reproduce the above copyright notice,
+ *    this list of conditions and the following disclaimer in the documentation
+ *    and/or other materials provided with the distribution.
+ *
+ * 3. The name of Atmel may not be used to endorse or promote products derived
+ *    from this software without specific prior written permission.
+ *
+ * 4. This software may only be redistributed and used in connection with an
+ *    Atmel microcontroller product.
+ *
+ * THIS SOFTWARE IS PROVIDED BY ATMEL "AS IS" AND ANY EXPRESS OR IMPLIED
+ * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
+ * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT ARE
+ * EXPRESSLY AND SPECIFICALLY DISCLAIMED. IN NO EVENT SHALL ATMEL BE LIABLE FOR
+ * ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+ * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
+ * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
+ * ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+ * POSSIBILITY OF SUCH DAMAGE.
+ *
+ * \asf_license_stop
+ *
+ */
+
+#ifndef _HAL_SLEEP_H_INCLUDED
+#define _HAL_SLEEP_H_INCLUDED
+
+#include <hpl_sleep.h>
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+/**
+ * \addtogroup doc_driver_hal_helper_sleep
+ *
+ *@{
+ */
+
+/**
+ * \brief Set the sleep mode of the device and put the MCU to sleep
+ *
+ * For an overview of which systems are disabled in sleep for the different
+ * sleep modes, see the data sheet.
+ *
+ * \param[in] mode Sleep mode to use
+ *
+ * \return The status of a sleep request
+ * \retval -1 The requested sleep mode was invalid or not available
+ * \retval  0 The operation completed successfully, returned after leaving the
+ *            sleep
+ */
+int sleep(const uint8_t mode);
+
+/**
+ * \brief Retrieve the current driver version
+ *
+ * \return Current driver version.
+ */
+uint32_t sleep_get_version(void);
+/**@}*/
+#ifdef __cplusplus
+}
+#endif
+#endif /* _HAL_SLEEP_H_INCLUDED */
diff --git a/atmel-samd/asf4/samd21/hal/include/hal_spi_m_sync.h b/atmel-samd/asf4/samd21/hal/include/hal_spi_m_sync.h
new file mode 100644
index 000000000..2c630ff09
--- /dev/null
+++ b/atmel-samd/asf4/samd21/hal/include/hal_spi_m_sync.h
@@ -0,0 +1,220 @@
+/**
+ * \file
+ *
+ * \brief SPI related functionality declaration.
+ *
+ * Copyright (C) 2014 Atmel Corporation. All rights reserved.
+ *
+ * \asf_license_start
+ *
+ * \page License
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright notice,
+ *    this list of conditions and the following disclaimer.
+ *
+ * 2. Redistributions in binary form must reproduce the above copyright notice,
+ *    this list of conditions and the following disclaimer in the documentation
+ *    and/or other materials provided with the distribution.
+ *
+ * 3. The name of Atmel may not be used to endorse or promote products derived
+ *    from this software without specific prior written permission.
+ *
+ * 4. This software may only be redistributed and used in connection with an
+ *    Atmel microcontroller product.
+ *
+ * THIS SOFTWARE IS PROVIDED BY ATMEL "AS IS" AND ANY EXPRESS OR IMPLIED
+ * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
+ * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT ARE
+ * EXPRESSLY AND SPECIFICALLY DISCLAIMED. IN NO EVENT SHALL ATMEL BE LIABLE FOR
+ * ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+ * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
+ * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
+ * ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+ * POSSIBILITY OF SUCH DAMAGE.
+ *
+ * \asf_license_stop
+ *
+ */
+
+#ifndef _HAL_SPI_M_SYNC_H_INCLUDED
+#define _HAL_SPI_M_SYNC_H_INCLUDED
+
+#include <hal_io.h>
+#include <hpl_spi_m_sync.h>
+
+/**
+ * \addtogroup doc_driver_hal_spi_master_sync
+ *
+ * @{
+ */
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+/** \brief SPI HAL driver struct for polling mode
+ *
+ */
+struct spi_m_sync_descriptor {
+	/** SPI device instance */
+	struct _spi_sync_dev dev;
+	/** I/O read/write */
+	struct io_descriptor io;
+	/** Flags for HAL driver */
+	uint16_t flags;
+};
+
+/** \brief Initialize SPI HAL instance and hardware for polling mode
+ *
+ *  Initialize SPI HAL with polling mode.
+ *
+ *  \param[in] spi Pointer to the HAL SPI instance.
+ *  \param[in] hw Pointer to the hardware base.
+ *
+ *  \return Operation status.
+ *  \retval ERR_NONE Success.
+ *  \retval ERR_INVALID_DATA Error, initialized.
+ */
+int32_t spi_m_sync_init(struct spi_m_sync_descriptor *spi, void *const hw);
+
+/** \brief Deinitialize the SPI HAL instance and hardware
+ *
+ *  Abort transfer, disable and reset SPI, deinit software.
+ *
+ *  \param[in] spi Pointer to the HAL SPI instance.
+ *
+ *  \return Operation status.
+ *  \retval ERR_NONE Success.
+ *  \retval <0 Error code.
+ */
+void spi_m_sync_deinit(struct spi_m_sync_descriptor *spi);
+
+/** \brief Enable SPI
+ *
+ *  \param[in] spi Pointer to the HAL SPI instance.
+ *
+ *  \return Operation status.
+ *  \retval ERR_NONE Success.
+ *  \retval <0 Error code.
+ */
+void spi_m_sync_enable(struct spi_m_sync_descriptor *spi);
+
+/** \brief Disable SPI
+ *
+ *  \param[in] spi Pointer to the HAL SPI instance.
+ *
+ *  \return Operation status.
+ *  \retval ERR_NONE Success.
+ *  \retval <0 Error code.
+ */
+void spi_m_sync_disable(struct spi_m_sync_descriptor *spi);
+
+/** \brief Set SPI baudrate
+ *
+ *  Works if SPI is initialized as master, it sets the baudrate.
+ *
+ *  \param[in] spi Pointer to the HAL SPI instance.
+ *  \param[in] baud_val The target baudrate value
+ *                  (see "baudrate calculation" for calculating the value).
+ *
+ *  \return Operation status.
+ *  \retval ERR_NONE Success.
+ *  \retval ERR_BUSY Busy
+ *  \retval ERR_INVALID_ARG The baudrate is not supported.
+ */
+int32_t spi_m_sync_set_baudrate(struct spi_m_sync_descriptor *spi, const uint32_t baud_val);
+
+/** \brief Set SPI mode
+ *
+ *  Set the SPI transfer mode (\ref spi_transfer_mode),
+ *  which controls the clock polarity and clock phase:
+ *  - Mode 0: leading edge is rising edge, data sample on leading edge.
+ *  - Mode 1: leading edge is rising edge, data sample on trailing edge.
+ *  - Mode 2: leading edge is falling edge, data sample on leading edge.
+ *  - Mode 3: leading edge is falling edge, data sample on trailing edge.
+ *
+ *  \param[in] spi Pointer to the HAL SPI instance.
+ *  \param[in] mode The mode (0~3).
+ *
+ *  \return Operation status.
+ *  \retval ERR_NONE Success.
+ *  \retval ERR_BUSY Busy
+ *  \retval ERR_INVALID_ARG The mode is not supported.
+ */
+int32_t spi_m_sync_set_mode(struct spi_m_sync_descriptor *spi, const enum spi_transfer_mode mode);
+
+/** \brief Set SPI transfer character size in number of bits
+ *
+ *  The character size (\ref spi_char_size) influence the way the data is
+ *  sent/received.
+ *  For char size <= 8-bit, data is stored byte by byte.
+ *  For char size between 9-bit ~ 16-bit, data is stored in 2-byte length.
+ *  Note that the default and recommended char size is 8-bit since it's
+ *  supported by all system.
+ *
+ *  \param[in] spi Pointer to the HAL SPI instance.
+ *  \param[in] char_size The char size (~16, recommended 8).
+ *
+ *  \return Operation status.
+ *  \retval ERR_NONE Success.
+ *  \retval ERR_BUSY Busy
+ *  \retval ERR_INVALID_ARG The char size is not supported.
+ */
+int32_t spi_m_sync_set_char_size(struct spi_m_sync_descriptor *spi, const enum spi_char_size char_size);
+
+/** \brief Set SPI transfer data order
+ *
+ *  \param[in] spi Pointer to the HAL SPI instance.
+ *  \param[in] dord The data order: send LSB/MSB first.
+ *
+ *  \return Operation status.
+ *  \retval ERR_NONE Success.
+ *  \retval ERR_BUSY Busy
+ *  \retval ERR_INVALID_ARG The data order is not supported.
+ */
+int32_t spi_m_sync_set_data_order(struct spi_m_sync_descriptor *spi, const enum spi_data_order dord);
+
+/** \brief Perform the SPI data transfer (TX and RX) in polling way
+ *
+ *  Activate CS, do TX and RX and deactivate CS. It blocks.
+ *
+ *  \param[in, out] spi Pointer to the HAL SPI instance.
+ *  \param[in] xfer Pointer to the transfer information (\ref spi_xfer).
+ *
+ *  \retval size Success.
+ *  \retval >=0 Timeout, with number of characters transferred.
+ *  \retval ERR_BUSY SPI is busy
+ */
+int32_t spi_m_sync_transfer(struct spi_m_sync_descriptor *spi, const struct spi_xfer *xfer);
+
+/**
+ * \brief Return the I/O descriptor for this SPI instance
+ *
+ * This function will return an I/O instance for this SPI driver instance.
+ *
+ * \param[in] spi An SPI master descriptor, which is used to communicate through
+ *                SPI
+ * \param[in, out] io A pointer to an I/O descriptor pointer type
+ *
+ * \retval ERR_NONE
+ */
+int32_t spi_m_sync_get_io_descriptor(struct spi_m_sync_descriptor *const spi, struct io_descriptor **io);
+
+/** \brief Retrieve the current driver version
+ *
+ *  \return Current driver version.
+ */
+uint32_t spi_m_sync_get_version(void);
+
+/**@}*/
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif /* ifndef _HAL_SPI_M_SYNC_H_INCLUDED */
diff --git a/atmel-samd/asf4/samd21/hal/include/hal_timer.h b/atmel-samd/asf4/samd21/hal/include/hal_timer.h
new file mode 100644
index 000000000..b5c8f6082
--- /dev/null
+++ b/atmel-samd/asf4/samd21/hal/include/hal_timer.h
@@ -0,0 +1,216 @@
+/**
+ * \file
+ *
+ * \brief Timer task functionality declaration.
+ *
+ * Copyright (C) 2014 - 2016 Atmel Corporation. All rights reserved.
+ *
+ * \asf_license_start
+ *
+ * \page License
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright notice,
+ *    this list of conditions and the following disclaimer.
+ *
+ * 2. Redistributions in binary form must reproduce the above copyright notice,
+ *    this list of conditions and the following disclaimer in the documentation
+ *    and/or other materials provided with the distribution.
+ *
+ * 3. The name of Atmel may not be used to endorse or promote products derived
+ *    from this software without specific prior written permission.
+ *
+ * 4. This software may only be redistributed and used in connection with an
+ *    Atmel microcontroller product.
+ *
+ * THIS SOFTWARE IS PROVIDED BY ATMEL "AS IS" AND ANY EXPRESS OR IMPLIED
+ * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
+ * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT ARE
+ * EXPRESSLY AND SPECIFICALLY DISCLAIMED. IN NO EVENT SHALL ATMEL BE LIABLE FOR
+ * ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+ * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
+ * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
+ * ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+ * POSSIBILITY OF SUCH DAMAGE.
+ *
+ * \asf_license_stop
+ *
+ */
+
+#ifndef _HAL_TIMER_H_INCLUDED
+#define _HAL_TIMER_H_INCLUDED
+
+#include <utils_list.h>
+#include <hpl_timer.h>
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+/**
+ * \addtogroup doc_driver_hal_timer
+ *
+ * @{
+ */
+
+/**
+ * \brief Timer mode type
+ */
+enum timer_task_mode { TIMER_TASK_ONE_SHOT, TIMER_TASK_REPEAT };
+
+/**
+ * \brief Timer task descriptor
+ *
+ * The timer task descriptor forward declaration.
+ */
+struct timer_task;
+
+/**
+ * \brief Timer task callback function type
+ */
+typedef void (*timer_cb_t)(const struct timer_task *const timer_task);
+
+/**
+ * \brief Timer task structure
+ */
+struct timer_task {
+	struct list_element elem;       /*! List element. */
+	uint32_t            time_label; /*! Absolute timer start time. */
+
+	uint32_t             interval; /*! Number of timer ticks before calling the task. */
+	timer_cb_t           cb;       /*! Function pointer to the task. */
+	enum timer_task_mode mode;     /*! Task mode: one shot or repeat. */
+};
+
+/**
+ * \brief Timer structure
+ */
+struct timer_descriptor {
+	struct _timer_device   device;
+	uint32_t               time;
+	struct list_descriptor tasks; /*! Timer tasks list. */
+	volatile uint8_t       flags;
+};
+
+/**
+ * \brief Initialize timer
+ *
+ * This function initializes the given timer.
+ * It checks if the given hardware is not initialized and if the given hardware
+ * is permitted to be initialized.
+ *
+ * \param[out] descr A timer descriptor to initialize
+ * \param[in] hw The pointer to the hardware instance
+ * \param[in] func The pointer to a set of function pointers
+ *
+ * \return Initialization status.
+ */
+int32_t timer_init(struct timer_descriptor *const descr, void *const hw, struct _timer_hpl_interface *const func);
+
+/**
+ * \brief Deinitialize timer
+ *
+ * This function deinitializes the given timer.
+ * It checks if the given hardware is initialized and if the given hardware is
+ * permitted to be deinitialized.
+ *
+ * \param[in] descr A timer descriptor to deinitialize
+ *
+ * \return De-initialization status.
+ */
+int32_t timer_deinit(struct timer_descriptor *const descr);
+
+/**
+ * \brief Start timer
+ *
+ * This function starts the given timer.
+ * It checks if the given hardware is initialized.
+ *
+ * \param[in] descr The timer descriptor of a timer to start
+ *
+ * \return Timer starting status.
+ */
+int32_t timer_start(struct timer_descriptor *const descr);
+
+/**
+ * \brief Stop timer
+ *
+ * This function stops the given timer.
+ * It checks if the given hardware is initialized.
+ *
+ * \param[in] descr The timer descriptor of a timer to stop
+ *
+ * \return Timer stopping status.
+ */
+int32_t timer_stop(struct timer_descriptor *const descr);
+
+/**
+ * \brief Set amount of clock cycles per timer tick
+ *
+ * This function sets the amount of clock cycles per timer tick for the given timer.
+ * It checks if the given hardware is initialized.
+ *
+ * \param[in] descr The timer descriptor of a timer to stop
+ * \param[in] clock_cycles The amount of clock cycles per tick to set
+ *
+ * \return Setting clock cycles amount status.
+ */
+int32_t timer_set_clock_cycles_per_tick(struct timer_descriptor *const descr, const uint32_t clock_cycles);
+
+/**
+ * \brief Retrieve the amount of clock cycles in a tick
+ *
+ * This function retrieves how many clock cycles there are in a single timer tick.
+ * It checks if the given hardware is initialized.
+ *
+ * \param[in]  descr The timer descriptor of a timer to convert ticks to
+ * clock cycles
+ * \param[out] cycles The amount of clock cycles
+ *
+ * \return The status of clock cycles retrieving.
+ */
+int32_t timer_get_clock_cycles_in_tick(const struct timer_descriptor *const descr, uint32_t *const cycles);
+
+/**
+ * \brief Add timer task
+ *
+ * This function adds the given timer task to the given timer.
+ * It checks if the given hardware is initialized.
+ *
+ * \param[in] descr The timer descriptor of a timer to add task to
+ * \param[in] task A task to add
+ *
+ * \return Timer's task adding status.
+ */
+int32_t timer_add_task(struct timer_descriptor *const descr, struct timer_task *const task);
+
+/**
+ * \brief Remove timer task
+ *
+ * This function removes the given timer task from the given timer.
+ * It checks if the given hardware is initialized.
+ *
+ * \param[in] descr The timer descriptor of a timer to remove task from
+ * \param[in] task A task to remove
+ *
+ * \return Timer's task removing status.
+ */
+int32_t timer_remove_task(struct timer_descriptor *const descr, const struct timer_task *const task);
+
+/**
+ * \brief Retrieve the current driver version
+ *
+ * \return Current driver version.
+ */
+uint32_t timer_get_version(void);
+/**@}*/
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif /* _HAL_TIMER_H_INCLUDED */
diff --git a/atmel-samd/asf4/samd21/hal/include/hal_usart_sync.h b/atmel-samd/asf4/samd21/hal/include/hal_usart_sync.h
new file mode 100644
index 000000000..e2aef748d
--- /dev/null
+++ b/atmel-samd/asf4/samd21/hal/include/hal_usart_sync.h
@@ -0,0 +1,257 @@
+/**
+ * \file
+ *
+ * \brief USART related functionality declaration.
+ *
+ * Copyright (C) 2014 Atmel Corporation. All rights reserved.
+ *
+ * \asf_license_start
+ *
+ * \page License
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright notice,
+ *    this list of conditions and the following disclaimer.
+ *
+ * 2. Redistributions in binary form must reproduce the above copyright notice,
+ *    this list of conditions and the following disclaimer in the documentation
+ *    and/or other materials provided with the distribution.
+ *
+ * 3. The name of Atmel may not be used to endorse or promote products derived
+ *    from this software without specific prior written permission.
+ *
+ * 4. This software may only be redistributed and used in connection with an
+ *    Atmel microcontroller product.
+ *
+ * THIS SOFTWARE IS PROVIDED BY ATMEL "AS IS" AND ANY EXPRESS OR IMPLIED
+ * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
+ * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT ARE
+ * EXPRESSLY AND SPECIFICALLY DISCLAIMED. IN NO EVENT SHALL ATMEL BE LIABLE FOR
+ * ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+ * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
+ * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
+ * ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+ * POSSIBILITY OF SUCH DAMAGE.
+ *
+ * \asf_license_stop
+ *
+ */
+
+#ifndef _HAL_SYNC_USART_H_INCLUDED
+#define _HAL_SYNC_USART_H_INCLUDED
+
+#include "hal_io.h"
+#include <hpl_usart_sync.h>
+
+/**
+ * \addtogroup doc_driver_hal_usart_sync
+ *
+ * @{
+ */
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+/**
+ * \brief Synchronous USART descriptor
+ */
+struct usart_sync_descriptor {
+	struct io_descriptor      io;
+	struct _usart_sync_device device;
+};
+
+/**
+ * \brief Initialize USART interface
+ *
+ * This function initializes the given I/O descriptor to be used
+ * as USART interface descriptor.
+ * It checks if the given hardware is not initialized and
+ * if the given hardware is permitted to be initialized.
+ *
+ * \param[out] descr A USART descriptor which is used to communicate via USART
+ * \param[in] hw The pointer to hardware instance
+ * \param[in] func The pointer to as set of functions pointers
+ *
+ * \return Initialization status.
+ */
+int32_t usart_sync_init(struct usart_sync_descriptor *const descr, void *const hw, void *const func);
+
+/**
+ * \brief Deinitialize USART interface
+ *
+ * This function deinitializes the given I/O descriptor.
+ * It checks if the given hardware is initialized and
+ * if the given hardware is permitted to be deinitialized.
+ *
+ * \param[in] descr A USART descriptor which is used to communicate via USART
+ *
+ * \return De-initialization status.
+ */
+int32_t usart_sync_deinit(struct usart_sync_descriptor *const descr);
+
+/**
+ * \brief Enable USART interface
+ *
+ * Enables the USART interface
+ *
+ * \param[in] descr A USART descriptor which is used to communicate via USART
+ *
+ * \return Enabling status.
+ */
+int32_t usart_sync_enable(struct usart_sync_descriptor *const descr);
+
+/**
+ * \brief Disable USART interface
+ *
+ * Disables the USART interface
+ *
+ * \param[in] descr A USART descriptor which is used to communicate via USART
+ *
+ * \return Disabling status.
+ */
+int32_t usart_sync_disable(struct usart_sync_descriptor *const descr);
+
+/**
+ * \brief Retrieve I/O descriptor
+ *
+ * This function retrieves the I/O descriptor of the given USART descriptor.
+ *
+ * \param[in] descr A USART descriptor which is used to communicate via USART
+ * \param[out] io An I/O descriptor to retrieve
+ *
+ * \return The status of the I/O descriptor retrieving.
+ */
+int32_t usart_sync_get_io_descriptor(struct usart_sync_descriptor *const descr, struct io_descriptor **io);
+
+/**
+ * \brief Specify action for flow control pins
+ *
+ * This function sets the action (or state) for the flow control pins
+ * if the flow control is enabled.
+ * It sets the state of flow control pins only if the automatic support of
+ * the flow control is not supported by the hardware.
+ *
+ * \param[in] descr A USART descriptor which is used to communicate via USART
+ * \param[in] state A state to set the flow control pins
+ *
+ * \return The status of flow control action setup.
+ */
+int32_t usart_sync_set_flow_control(struct usart_sync_descriptor *const  descr,
+                                    const union usart_flow_control_state state);
+
+/**
+ * \brief Set USART baud rate
+ *
+ * \param[in] descr A USART descriptor which is used to communicate via USART
+ * \param[in] baud_rate A baud rate to set
+ *
+ * \return The status of baud rate setting.
+ */
+int32_t usart_sync_set_baud_rate(struct usart_sync_descriptor *const descr, const uint32_t baud_rate);
+
+/**
+ * \brief Set USART data order
+ *
+ * \param[in] descr A USART descriptor which is used to communicate via USART
+ * \param[in] data_order A data order to set
+ *
+ * \return The status of data order setting.
+ */
+int32_t usart_sync_set_data_order(struct usart_sync_descriptor *const descr, const enum usart_data_order data_order);
+
+/**
+ * \brief Set USART mode
+ *
+ * \param[in] descr A USART descriptor which is used to communicate via USART
+ * \param[in] mode A mode to set
+ *
+ * \return The status of mode setting.
+ */
+int32_t usart_sync_set_mode(struct usart_sync_descriptor *const descr, const enum usart_mode mode);
+
+/**
+ * \brief Set USART parity
+ *
+ * \param[in] descr A USART descriptor which is used to communicate via USART
+ * \param[in] parity A parity to set
+ *
+ * \return The status of parity setting.
+ */
+int32_t usart_sync_set_parity(struct usart_sync_descriptor *const descr, const enum usart_parity parity);
+
+/**
+ * \brief Set USART stop bits
+ *
+ * \param[in] descr A USART descriptor which is used to communicate via USART
+ * \param[in] stop_bits Stop bits to set
+ *
+ * \return The status of stop bits setting.
+ */
+int32_t usart_sync_set_stopbits(struct usart_sync_descriptor *const descr, const enum usart_stop_bits stop_bits);
+
+/**
+ * \brief Set USART character size
+ *
+ * \param[in] descr A USART descriptor which is used to communicate via USART
+ * \param[in] size A character size to set
+ *
+ * \return The status of character size setting.
+ */
+int32_t usart_sync_set_character_size(struct usart_sync_descriptor *const descr, const enum usart_character_size size);
+
+/**
+ * \brief Retrieve the state of flow control pins
+ *
+ * This function retrieves the of flow control pins
+ * if the flow control is enabled.
+ * Function can return USART_FLOW_CONTROL_STATE_UNAVAILABLE in case
+ * if the flow control is done by the hardware
+ * and the pins state cannot be read out.
+ *
+ * \param[in] descr A USART descriptor which is used to communicate via USART
+ * \param[out] state The state of flow control pins
+ *
+ * \return The status of flow control state reading.
+ */
+int32_t usart_sync_flow_control_status(const struct usart_sync_descriptor *const descr,
+                                       union usart_flow_control_state *const     state);
+
+/**
+ * \brief Check if the USART transmitter is empty
+ *
+ * \param[in] descr A USART descriptor which is used to communicate via USART
+ *
+ * \return The status of USART TX empty checking.
+ * \retval 0 The USART transmitter is not empty
+ * \retval 1 The USART transmitter is empty
+ */
+int32_t usart_sync_is_tx_empty(const struct usart_sync_descriptor *const descr);
+
+/**
+ * \brief Check if the USART receiver is not empty
+ *
+ * \param[in] descr A USART descriptor which is used to communicate via USART
+ *
+ * \return The status of USART RX empty checking.
+ * \retval 1 The USART receiver is not empty
+ * \retval 0 The USART receiver is empty
+ */
+int32_t usart_sync_is_rx_not_empty(const struct usart_sync_descriptor *const descr);
+
+/**
+ * \brief Retrieve the current driver version
+ *
+ * \return Current driver version.
+ */
+uint32_t usart_sync_get_version(void);
+
+#ifdef __cplusplus
+}
+#endif
+/**@}*/
+#endif /* _HAL_SYNC_USART_H_INCLUDED */
diff --git a/atmel-samd/asf4/samd21/hal/include/hal_usb_device.h b/atmel-samd/asf4/samd21/hal/include/hal_usb_device.h
new file mode 100644
index 000000000..8b7bd5ec7
--- /dev/null
+++ b/atmel-samd/asf4/samd21/hal/include/hal_usb_device.h
@@ -0,0 +1,305 @@
+/**
+ * \file
+ *
+ * \brief SAM USB device HAL
+ *
+ * Copyright (C) 2015 Atmel Corporation. All rights reserved.
+ *
+ * \asf_license_start
+ *
+ * \page License
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright notice,
+ *    this list of conditions and the following disclaimer.
+ *
+ * 2. Redistributions in binary form must reproduce the above copyright notice,
+ *    this list of conditions and the following disclaimer in the documentation
+ *    and/or other materials provided with the distribution.
+ *
+ * 3. The name of Atmel may not be used to endorse or promote products derived
+ *    from this software without specific prior written permission.
+ *
+ * 4. This software may only be redistributed and used in connection with an
+ *    Atmel microcontroller product.
+ *
+ * THIS SOFTWARE IS PROVIDED BY ATMEL "AS IS" AND ANY EXPRESS OR IMPLIED
+ * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
+ * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT ARE
+ * EXPRESSLY AND SPECIFICALLY DISCLAIMED. IN NO EVENT SHALL ATMEL BE LIABLE FOR
+ * ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+ * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
+ * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
+ * ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+ * POSSIBILITY OF SUCH DAMAGE.
+ *
+ * \asf_license_stop
+ *
+ */
+
+#ifndef _HAL_USB_DEVICE_H_INCLUDED
+#define _HAL_USB_DEVICE_H_INCLUDED
+
+#include <hpl_usb_device.h>
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+/**
+ * \addtogroup doc_driver_hal_usb_device
+ *
+ * @{
+ */
+
+/** USB device endpoint status structure. */
+struct usb_d_ep_status {
+	/** Endpoint address, including direction. */
+	uint8_t ep;
+	/** Endpoint transfer status code that triggers the callback.
+	 *  \ref usb_xfer_code. */
+	uint8_t code;
+	/** Endpoint error, if \c code is \ref USB_TRANS_ERROR. */
+	uint8_t error;
+	/** Transfer state, \ref usb_ep_state. */
+	uint8_t state;
+	/** Transfer count. */
+	uint32_t count;
+	/** Transfer size. */
+	uint32_t size;
+};
+
+/** Prototype function for callback that is invoked on USB device SOF. */
+typedef void (*usb_d_sof_cb_t)(void);
+
+/** Prototype function for callback that is invoked on USB device events. */
+typedef void (*usb_d_event_cb_t)(const enum usb_event event, const uint32_t param);
+
+/** USB device callbacks. */
+struct usb_d_callbacks {
+	/** Callback that is invoked on SOF. */
+	usb_d_sof_cb_t sof;
+	/** Callback that is invoked on USB RESET/WAKEUP/RESUME/SUSPEND. */
+	usb_d_event_cb_t event;
+};
+
+/** Callback that is invoked when setup packet is received.
+ *  Return \c true if request has been handled, or control endpoint will
+ *  stall IN/OUT transactions.
+ */
+typedef bool (*usb_d_ep_cb_setup_t)(const uint8_t ep, const uint8_t *req);
+
+/** Callback that is invoked when buffer is done without error, but last packet
+ *  is full size packet without ZLP.
+ *  Return \c true if more data has been requested.
+ */
+typedef bool (*usb_d_ep_cb_more_t)(const uint8_t ep, const uint32_t count);
+
+/** Callback that is invoked when all data is finished, including background
+ *  transfer, or error happens.
+ *  In control transfer data stage, return value is checked,
+ *  return \c false if no error happens.
+ */
+typedef bool (*usb_d_ep_cb_xfer_t)(const uint8_t ep, const enum usb_xfer_code code, void *param);
+
+/**
+ *  \brief Initialize the USB device driver
+ *  \return Operation status.
+ *  \retval 0 Success.
+ *  \retval <0 Error code.
+ */
+int32_t usb_d_init(void);
+
+/**
+ *  \brief Deinitialize the USB device driver
+ */
+void usb_d_deinit(void);
+
+/**
+ *  \brief Register the USB device callback
+ *  \param[in] type The callback type to register.
+ *  \param[in] func The callback function, NULL to disable callback.
+ */
+void usb_d_register_callback(const enum usb_d_cb_type type, const FUNC_PTR func);
+
+/**
+ *  \brief Enable the USB device driver
+ *  \return Operation status.
+ *  \retval 0 Success.
+ *  \retval <0 Error code.
+ */
+int32_t usb_d_enable(void);
+
+/**
+ *  \brief Disable the USB device driver
+ */
+void usb_d_disable(void);
+
+/**
+ *  \brief Attach the USB device
+ */
+void usb_d_attach(void);
+
+/**
+ *  \brief Detach the USB device
+ */
+void usb_d_detach(void);
+
+/**
+ *  \brief Retrieve current USB working speed.
+ *  \return USB Speed. See \ref usb_speed.
+ */
+enum usb_speed usb_d_get_speed(void);
+
+/**
+ *  \brief Retrieve current USB frame number.
+ *  \return Frame number.
+ */
+uint16_t usb_d_get_frame_num(void);
+
+/**
+ *  \brief Retrieve current USB micro frame number.
+ *  \return Micro frame number inside a frame (0~7).
+ *          0 if not available (not HS).
+ */
+uint8_t usb_d_get_uframe_num(void);
+
+/**
+ *  \brief Set the USB address that is used.
+ *  \param[in] addr The address to set.
+ */
+void usb_d_set_address(const uint8_t addr);
+
+/**
+ *  \brief Send remote wakeup to host
+ *  \return Operation status.
+ */
+void usb_d_send_remotewakeup(void);
+
+/**
+ *  \brief Initialize the endpoint 0.
+ *
+ *  Note that endpoint 0 must be initialized as control endpoint.
+ *
+ *  \param[in] max_pkt_size Max. packet size of EP0.
+ *  \return Operation status.
+ *  \retval 0 Success.
+ *  \retval <0 Error code.
+ */
+int32_t usb_d_ep0_init(const uint8_t max_pkt_size);
+
+/**
+ *  \brief Initialize the endpoint.
+ *
+ *  \param[in] ep The endpoint address.
+ *  \param[in] attr The endpoint attributes.
+ *  \param[in] max_pkt_size Max. packet size of EP0.
+ *  \return Operation status.
+ *  \retval 0 Success.
+ *  \retval <0 Error code.
+ */
+int32_t usb_d_ep_init(const uint8_t ep, const uint8_t attr, const uint16_t max_pkt_size);
+
+/**
+ *  \brief Disable and deinitialize the endpoint.
+ *  \param[in] ep The endpoint address to deinitialize.
+ */
+void usb_d_ep_deinit(const uint8_t ep);
+
+/**
+ *  \brief Register the USB device endpoint callback on initialized endpoint.
+ *
+ *  \param[in] ep The endpoint address.
+ *  \param[in] type The callback type to register.
+ *  \param[in] func The callback function, NULL to disable callback.
+ */
+void usb_d_ep_register_callback(const uint8_t ep, const enum usb_d_ep_cb_type type, const FUNC_PTR func);
+
+/**
+ *  \brief Enabled the initialized endpoint.
+ *
+ *  Setup request will be monitored after enabling a control endpoint.
+ *
+ *  \param[in] ep The endpoint address.
+ *  \return Operation status.
+ *  \retval 0 Success.
+ *  \retval <0 Error code.
+ */
+int32_t usb_d_ep_enable(const uint8_t ep);
+
+/**
+ *  \brief Disable the initialized endpoint.
+ *  \param[in] ep The endpoint address.
+ */
+void usb_d_ep_disable(const uint8_t ep);
+
+/**
+ *  \brief Get request data pointer to access received setup request packet
+ *  \param[in] ep The endpoint address.
+ *  \return Pointer to the request data.
+ *  \retval NULL The endpoint is not a control endpoint.
+ */
+uint8_t *usb_d_ep_get_req(const uint8_t ep);
+
+/**
+ *  \brief Endpoint transfer.
+ *
+ *  For control endpoints, start the transfer according to the direction in the bmRequest
+ *  type, and finish with STATUS stage.
+ *  For non-control endpoints, the transfer will be unique direction. Defined by
+ *  bit 8 of the endpoint address.
+ *
+ *  \param[in] xfer Pointer to the transfer description.
+ *  \return Operation status.
+ *  \retval 0 Success.
+ *  \retval <0 Error code.
+ */
+int32_t usb_d_ep_transfer(const struct usb_d_transfer *xfer);
+
+/**
+ *  \brief Abort an on-going transfer on a specific endpoint.
+ *
+ *  \param[in] ep The endpoint address.
+ */
+void usb_d_ep_abort(const uint8_t ep);
+
+/**
+ *  \brief Retrieve the endpoint status.
+ *
+ *  \param[in] ep The endpoint address.
+ *  \param[out] stat Pointer to the buffer to fill the status description.
+ *
+ *  \return Endpoint status.
+ *  \retval 1 Busy.
+ *  \retval 0 Idle.
+ *  \retval <0 Error code.
+ */
+int32_t usb_d_ep_get_status(const uint8_t ep, struct usb_d_ep_status *stat);
+
+/**
+ *  \brief Endpoint halt control.
+ *
+ *  \param[in] ep The endpoint address.
+ *  \param[in] ctrl Control code (SET/CLEAR/GET).
+ *
+ *  \return Operation status or HALT state (if \c ctrl is \ref USB_EP_HALT_GET).
+ */
+int32_t usb_d_ep_halt(const uint8_t ep, const enum usb_ep_halt_ctrl ctrl);
+
+/** \brief Retrieve the current driver version
+ *
+ *  \return Current driver version.
+ */
+uint32_t usb_d_get_version(void);
+
+/**@}*/
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif /* _HAL_USB_DEVICE_H_INCLUDED */
diff --git a/atmel-samd/asf4/samd21/hal/include/hpl_adc_async.h b/atmel-samd/asf4/samd21/hal/include/hpl_adc_async.h
new file mode 100644
index 000000000..31612be00
--- /dev/null
+++ b/atmel-samd/asf4/samd21/hal/include/hpl_adc_async.h
@@ -0,0 +1,274 @@
+/**
+ * \file
+ *
+ * \brief ADC related functionality declaration.
+ *
+ * Copyright (C) 2015-2016 Atmel Corporation. All rights reserved.
+ *
+ * \asf_license_start
+ *
+ * \page License
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright notice,
+ *    this list of conditions and the following disclaimer.
+ *
+ * 2. Redistributions in binary form must reproduce the above copyright notice,
+ *    this list of conditions and the following disclaimer in the documentation
+ *    and/or other materials provided with the distribution.
+ *
+ * 3. The name of Atmel may not be used to endorse or promote products derived
+ *    from this software without specific prior written permission.
+ *
+ * 4. This software may only be redistributed and used in connection with an
+ *    Atmel microcontroller product.
+ *
+ * THIS SOFTWARE IS PROVIDED BY ATMEL "AS IS" AND ANY EXPRESS OR IMPLIED
+ * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
+ * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT ARE
+ * EXPRESSLY AND SPECIFICALLY DISCLAIMED. IN NO EVENT SHALL ATMEL BE LIABLE FOR
+ * ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+ * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
+ * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
+ * ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+ * POSSIBILITY OF SUCH DAMAGE.
+ *
+ * \asf_license_stop
+ *
+ */
+
+#ifndef _HPL_ADC_ASYNC_H_INCLUDED
+#define _HPL_ADC_ASYNC_H_INCLUDED
+
+/**
+ * \addtogroup HPL ADC
+ *
+ * \section hpl_async_adc_rev Revision History
+ * - v1.0.0 Initial Release
+ *
+ *@{
+ */
+
+#include "hpl_adc_sync.h"
+#include "hpl_irq.h"
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+/**
+ * \brief ADC device structure
+ *
+ * The ADC device structure forward declaration.
+ */
+struct _adc_async_device;
+
+/**
+ * \brief ADC callback types
+ */
+enum _adc_async_callback_type { ADC_ASYNC_DEVICE_CONVERT_CB, ADC_ASYNC_DEVICE_MONITOR_CB, ADC_ASYNC_DEVICE_ERROR_CB };
+
+/**
+ * \brief ADC interrupt callbacks
+ */
+struct _adc_async_callbacks {
+	void (*window_cb)(struct _adc_async_device *device, const uint8_t channel);
+	void (*error_cb)(struct _adc_async_device *device, const uint8_t channel);
+};
+
+/**
+ * \brief ADC channel interrupt callbacks
+ */
+struct _adc_async_ch_callbacks {
+	void (*convert_done)(struct _adc_async_device *device, const uint8_t channel, const uint16_t data);
+};
+
+/**
+ * \brief ADC descriptor device structure
+ */
+struct _adc_async_device {
+	struct _adc_async_callbacks    adc_async_cb;
+	struct _adc_async_ch_callbacks adc_async_ch_cb;
+	struct _irq_descriptor         irq;
+	void *                         hw;
+};
+
+/**
+ * \name HPL functions
+ */
+//@{
+/**
+ * \brief Initialize synchronous ADC
+ *
+ * This function does low level ADC configuration.
+ *
+ * param[in] device The pointer to ADC device instance
+ * param[in] hw     The pointer to hardware instance
+ *
+ * \return Initialization status
+ */
+int32_t _adc_async_init(struct _adc_async_device *const device, void *const hw);
+
+/**
+ * \brief Deinitialize ADC
+ *
+ * \param[in] device The pointer to ADC device instance
+ */
+void _adc_async_deinit(struct _adc_async_device *const device);
+
+/**
+ * \brief Enable ADC peripheral
+ *
+ * \param[in] device   The pointer to ADC device instance
+ * \param[in] channel  Channel number
+ */
+void _adc_async_enable_channel(struct _adc_async_device *const device, const uint8_t channel);
+
+/**
+ * \brief Disable ADC peripheral
+ *
+ * \param[in] device   The pointer to ADC device instance
+ * \param[in] channel  Channel number
+ */
+void _adc_async_disable_channel(struct _adc_async_device *const device, const uint8_t channel);
+
+/**
+ * \brief Retrieve ADC conversion data size
+ *
+ * \param[in] device The pointer to ADC device instance
+ *
+ * \return The data size in bytes
+ */
+uint8_t _adc_async_get_data_size(const struct _adc_async_device *const device);
+
+/**
+ * \brief Check if conversion is done
+ *
+ * \param[in] device  The pointer to ADC device instance
+ * \param[in] channel Channel number
+ *
+ * \return The status of conversion
+ * \retval true The conversion is done
+ * \retval false The conversion is not done
+ */
+bool _adc_async_is_channel_conversion_done(const struct _adc_async_device *const device, const uint8_t channel);
+
+/**
+ * \brief Make conversion
+ *
+ * \param[in] device The pointer to ADC device instance
+ */
+void _adc_async_convert(struct _adc_async_device *const device);
+
+/**
+ * \brief Retrieve the conversion result
+ *
+ * \param[in] device  The pointer to ADC device instance
+ * \param[in] channel Channel number
+ *
+ * The result value
+ */
+uint16_t _adc_async_read_channel_data(const struct _adc_async_device *const device, const uint8_t channel);
+
+/**
+ * \brief Set reference source
+ *
+ * \param[in] device The pointer to ADC device instance
+ * \param[in] reference A reference source to set
+ */
+void _adc_async_set_reference_source(struct _adc_async_device *const device, const adc_reference_t reference);
+
+/**
+ * \brief Set resolution
+ *
+ * \param[in] device The pointer to ADC device instance
+ * \param[in] resolution A resolution to set
+ */
+void _adc_async_set_resolution(struct _adc_async_device *const device, const adc_resolution_t resolution);
+
+/**
+ * \brief Set ADC input source of a channel
+ *
+ * \param[in] device    The pointer to ADC device instance
+ * \param[in] pos_input A positive input source to set
+ * \param[in] neg_input A negative input source to set
+ * \param[in] channel   Channel number
+ */
+void _adc_async_set_inputs(struct _adc_async_device *const device, const adc_pos_input_t pos_input,
+                           const adc_neg_input_t neg_input, const uint8_t channel);
+
+/**
+ * \brief Set conversion mode
+ *
+ * \param[in] device The pointer to ADC device instance
+ * \param[in] mode A conversion mode to set
+ */
+void _adc_async_set_conversion_mode(struct _adc_async_device *const device, const enum adc_conversion_mode mode);
+
+/**
+ * \brief Set differential mode
+ *
+ * \param[in] device  The pointer to ADC device instance
+ * \param[in] channel Channel number
+ * \param[in] mode    A differential mode to set
+ */
+void _adc_async_set_channel_differential_mode(struct _adc_async_device *const device, const uint8_t channel,
+                                              const enum adc_differential_mode mode);
+
+/**
+ * \brief Set gain
+ *
+ * \param[in] device   The pointer to ADC device instance
+ * \param[in] channel  Channel number
+ * \param[in] gain     A gain to set
+ */
+void _adc_async_set_channel_gain(struct _adc_async_device *const device, const uint8_t channel, const adc_gain_t gain);
+
+/**
+ * \brief Set window mode
+ *
+ * \param[in] device The pointer to ADC device instance
+ * \param[in] mode   A mode to set
+ */
+void _adc_async_set_window_mode(struct _adc_async_device *const device, const adc_window_mode_t mode);
+
+/**
+ * \brief Set lower threshold
+ *
+ * \param[in] device        The pointer to ADC device instance
+ * \param[in] low_threshold  A lower threshold to set
+ * \param[in] up_threshold   An upper thresholds to set
+ */
+void _adc_async_set_thresholds(struct _adc_async_device *const device, const adc_threshold_t low_threshold,
+                               const adc_threshold_t up_threshold);
+
+/**
+ * \brief Retrieve threshold state
+ *
+ * \param[in] device The pointer to ADC device instance
+ * \param[out] state The threshold state
+ */
+void _adc_async_get_threshold_state(const struct _adc_async_device *const device, adc_threshold_status_t *const state);
+
+/**
+ * \brief Enable/disable ADC channel interrupt
+ *
+ * \param[in] device   The pointer to ADC device instance
+ * \param[in] channel  Channel number
+ * \param[in] type     The type of interrupt to disable/enable if applicable
+ * \param[in] state    Enable or disable
+ */
+void _adc_async_set_irq_state(struct _adc_async_device *const device, const uint8_t channel,
+                              const enum _adc_async_callback_type type, const bool state);
+
+//@}
+
+#ifdef __cplusplus
+}
+#endif
+/**@}*/
+#endif /* _HPL_ADC_ASYNC_H_INCLUDED */
diff --git a/atmel-samd/asf4/samd21/hal/include/hpl_adc_dma.h b/atmel-samd/asf4/samd21/hal/include/hpl_adc_dma.h
new file mode 100644
index 000000000..40ff158d2
--- /dev/null
+++ b/atmel-samd/asf4/samd21/hal/include/hpl_adc_dma.h
@@ -0,0 +1,253 @@
+/**
+ * \file
+ *
+ * \brief ADC related functionality declaration.
+ *
+ * Copyright (C) 2016 Atmel Corporation. All rights reserved.
+ *
+ * \asf_license_start
+ *
+ * \page License
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright notice,
+ *    this list of conditions and the following disclaimer.
+ *
+ * 2. Redistributions in binary form must reproduce the above copyright notice,
+ *    this list of conditions and the following disclaimer in the documentation
+ *    and/or other materials provided with the distribution.
+ *
+ * 3. The name of Atmel may not be used to endorse or promote products derived
+ *    from this software without specific prior written permission.
+ *
+ * 4. This software may only be redistributed and used in connection with an
+ *    Atmel microcontroller product.
+ *
+ * THIS SOFTWARE IS PROVIDED BY ATMEL "AS IS" AND ANY EXPRESS OR IMPLIED
+ * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
+ * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT ARE
+ * EXPRESSLY AND SPECIFICALLY DISCLAIMED. IN NO EVENT SHALL ATMEL BE LIABLE FOR
+ * ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+ * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
+ * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
+ * ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+ * POSSIBILITY OF SUCH DAMAGE.
+ *
+ * \asf_license_stop
+ *
+ */
+
+#ifndef _HPL_ADC_DMA_H_INCLUDED
+#define _HPL_ADC_DMA_H_INCLUDED
+
+/**
+ * \addtogroup HPL ADC
+ *
+ * \section hpl_dma_adc_rev Revision History
+ * - v1.0.0 Initial Release
+ *
+ *@{
+ */
+
+#include <hpl_adc_sync.h>
+#include <hpl_irq.h>
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+/**
+ * \brief ADC device structure
+ *
+ * The ADC device structure forward declaration.
+ */
+struct _adc_dma_device;
+
+/**
+ * \brief ADC callback types
+ */
+enum _adc_dma_callback_type { ADC_DMA_DEVICE_COMPLETE_CB, ADC_DMA_DEVICE_ERROR_CB };
+
+/**
+ * \brief ADC interrupt callbacks
+ */
+struct _adc_dma_callbacks {
+	void (*complete)(struct _adc_dma_device *device, const uint16_t data);
+	void (*error)(struct _adc_dma_device *device);
+};
+
+/**
+ * \brief ADC descriptor device structure
+ */
+struct _adc_dma_device {
+	struct _adc_dma_callbacks adc_dma_cb;
+	struct _irq_descriptor    irq;
+	void *                    hw;
+};
+
+/**
+ * \name HPL functions
+ */
+//@{
+/**
+ * \brief Initialize synchronous ADC
+ *
+ * This function does low level ADC configuration.
+ *
+ * param[in] device The pointer to ADC device instance
+ * param[in] hw The pointer to hardware instance
+ *
+ * \return Initialization status
+ */
+int32_t _adc_dma_init(struct _adc_dma_device *const device, void *const hw);
+
+/**
+ * \brief Deinitialize ADC
+ *
+ * \param[in] device The pointer to ADC device instance
+ */
+void _adc_dma_deinit(struct _adc_dma_device *const device);
+
+/**
+ * \brief Enable ADC peripheral
+ *
+ * \param[in] device   The pointer to ADC device instance
+ * \param[in] channel  Channel number
+ */
+void _adc_dma_enable_channel(struct _adc_dma_device *const device, const uint8_t channel);
+
+/**
+ * \brief Disable ADC peripheral
+ *
+ * \param[in] device   The pointer to ADC device instance
+ * \param[in] channel  Channel number
+ */
+void _adc_dma_disable_channel(struct _adc_dma_device *const device, const uint8_t channel);
+
+/**
+ * \brief Return address of ADC DMA source
+ *
+ * \param[in] device The pointer to ADC device instance
+ *
+ * \return ADC DMA source address
+ */
+uint32_t _adc_get_source_for_dma(struct _adc_dma_device *const device);
+
+/**
+ * \brief Retrieve ADC conversion data size
+ *
+ * \param[in] device The pointer to ADC device instance
+ *
+ * \return The data size in bytes
+ */
+uint8_t _adc_dma_get_data_size(const struct _adc_dma_device *const device);
+
+/**
+ * \brief Check if conversion is done
+ *
+ * \param[in] device   The pointer to ADC device instance
+ *
+ * \return The status of conversion
+ * \retval true The conversion is done
+ * \retval false The conversion is not done
+ */
+bool _adc_dma_is_conversion_done(const struct _adc_dma_device *const device);
+
+/**
+ * \brief Make conversion
+ *
+ * \param[in] device The pointer to ADC device instance
+ */
+void _adc_dma_convert(struct _adc_dma_device *const device);
+
+/**
+ * \brief Set reference source
+ *
+ * \param[in] device The pointer to ADC device instance
+ * \param[in] reference A reference source to set
+ */
+void _adc_dma_set_reference_source(struct _adc_dma_device *const device, const adc_reference_t reference);
+
+/**
+ * \brief Set resolution
+ *
+ * \param[in] device The pointer to ADC device instance
+ * \param[in] resolution A resolution to set
+ */
+void _adc_dma_set_resolution(struct _adc_dma_device *const device, const adc_resolution_t resolution);
+
+/**
+ * \brief Set ADC input source of a channel
+ *
+ * \param[in] device    The pointer to ADC device instance
+ * \param[in] pos_input A positive input source to set
+ * \param[in] neg_input A negative input source to set
+ * \param[in] channel   Channel number
+ */
+void _adc_dma_set_inputs(struct _adc_dma_device *const device, const adc_pos_input_t pos_input,
+                         const adc_neg_input_t neg_input, const uint8_t channel);
+
+/**
+ * \brief Set conversion mode
+ *
+ * \param[in] device The pointer to ADC device instance
+ * \param[in] mode A conversion mode to set
+ */
+void _adc_dma_set_conversion_mode(struct _adc_dma_device *const device, const enum adc_conversion_mode mode);
+
+/**
+ * \brief Set differential mode
+ *
+ * \param[in] device  The pointer to ADC device instance
+ * \param[in] channel Channel number
+ * \param[in] mode    A differential mode to set
+ */
+void _adc_dma_set_channel_differential_mode(struct _adc_dma_device *const device, const uint8_t channel,
+                                            const enum adc_differential_mode mode);
+
+/**
+ * \brief Set gain
+ *
+ * \param[in] device  The pointer to ADC device instance
+ * \param[in] channel Channel number
+ * \param[in] gain    A gain to set
+ */
+void _adc_dma_set_channel_gain(struct _adc_dma_device *const device, const uint8_t channel, const adc_gain_t gain);
+
+/**
+ * \brief Set window mode
+ *
+ * \param[in] device The pointer to ADC device instance
+ * \param[in] mode A mode to set
+ */
+void _adc_dma_set_window_mode(struct _adc_dma_device *const device, const adc_window_mode_t mode);
+
+/**
+ * \brief Set thresholds
+ *
+ * \param[in] device        The pointer to ADC device instance
+ * \param[in] low_threshold A lower thresholds to set
+ * \param[in] up_threshold  An upper thresholds to set
+ */
+void _adc_dma_set_thresholds(struct _adc_dma_device *const device, const adc_threshold_t low_threshold,
+                             const adc_threshold_t up_threshold);
+
+/**
+ * \brief Retrieve threshold state
+ *
+ * \param[in] device The pointer to ADC device instance
+ * \param[out] state The threshold state
+ */
+void _adc_dma_get_threshold_state(const struct _adc_dma_device *const device, adc_threshold_status_t *const state);
+
+//@}
+
+#ifdef __cplusplus
+}
+#endif
+/**@}*/
+#endif /* _HPL_ADC_DMA_H_INCLUDED */
diff --git a/atmel-samd/asf4/samd21/hal/include/hpl_adc_sync.h b/atmel-samd/asf4/samd21/hal/include/hpl_adc_sync.h
new file mode 100644
index 000000000..84ab01ab3
--- /dev/null
+++ b/atmel-samd/asf4/samd21/hal/include/hpl_adc_sync.h
@@ -0,0 +1,281 @@
+/**
+ * \file
+ *
+ * \brief ADC related functionality declaration.
+ *
+ * Copyright (C) 2014-2016 Atmel Corporation. All rights reserved.
+ *
+ * \asf_license_start
+ *
+ * \page License
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright notice,
+ *    this list of conditions and the following disclaimer.
+ *
+ * 2. Redistributions in binary form must reproduce the above copyright notice,
+ *    this list of conditions and the following disclaimer in the documentation
+ *    and/or other materials provided with the distribution.
+ *
+ * 3. The name of Atmel may not be used to endorse or promote products derived
+ *    from this software without specific prior written permission.
+ *
+ * 4. This software may only be redistributed and used in connection with an
+ *    Atmel microcontroller product.
+ *
+ * THIS SOFTWARE IS PROVIDED BY ATMEL "AS IS" AND ANY EXPRESS OR IMPLIED
+ * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
+ * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT ARE
+ * EXPRESSLY AND SPECIFICALLY DISCLAIMED. IN NO EVENT SHALL ATMEL BE LIABLE FOR
+ * ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+ * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
+ * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
+ * ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+ * POSSIBILITY OF SUCH DAMAGE.
+ *
+ * \asf_license_stop
+ *
+ */
+
+#ifndef _HPL_ADC_SYNC_H_INCLUDED
+#define _HPL_ADC_SYNC_H_INCLUDED
+
+/**
+ * \addtogroup HPL ADC
+ *
+ * \section hpl_adc_sync_rev Revision History
+ * - v1.0.0 Initial Release
+ *
+ *@{
+ */
+
+#include "compiler.h"
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+/**
+ * \brief ADC reference source
+ */
+typedef uint8_t adc_reference_t;
+
+/**
+ * \brief ADC resolution
+ */
+typedef uint8_t adc_resolution_t;
+
+/**
+ * \brief ADC positive input for channel
+ */
+typedef uint8_t adc_pos_input_t;
+
+/**
+ * \brief ADC negative input for channel
+ */
+typedef uint8_t adc_neg_input_t;
+
+/**
+ * \brief ADC threshold
+ */
+typedef uint16_t adc_threshold_t;
+
+/**
+ * \brief ADC gain
+ */
+typedef uint8_t adc_gain_t;
+
+/**
+ * \brief ADC conversion mode
+ */
+enum adc_conversion_mode { ADC_CONVERSION_MODE_SINGLE_CONVERSION = 0, ADC_CONVERSION_MODE_FREERUN };
+
+/**
+ * \brief ADC differential mode
+ */
+enum adc_differential_mode { ADC_DIFFERENTIAL_MODE_SINGLE_ENDED = 0, ADC_DIFFERENTIAL_MODE_DIFFERENTIAL };
+
+/**
+ * \brief ADC window mode
+ */
+typedef uint8_t adc_window_mode_t;
+
+/**
+ * \brief ADC threshold status
+ */
+typedef bool adc_threshold_status_t;
+
+/**
+ * \brief ADC sync descriptor device structure
+ */
+struct _adc_sync_device {
+	void *hw;
+};
+
+/**
+ * \name HPL functions
+ */
+//@{
+/**
+ * \brief Initialize synchronous ADC
+ *
+ * This function does low level ADC configuration.
+ *
+ * param[in] device The pointer to ADC device instance
+ * param[in] hw     The pointer to hardware instance
+ *
+ * \return Initialization status
+ */
+int32_t _adc_sync_init(struct _adc_sync_device *const device, void *const hw);
+
+/**
+ * \brief Deinitialize ADC
+ *
+ * \param[in] device The pointer to ADC device instance
+ */
+void _adc_sync_deinit(struct _adc_sync_device *const device);
+
+/**
+ * \brief Enable ADC
+ *
+ * \param[in] device   The pointer to ADC device instance
+ * \param[in] channel  Channel number
+ */
+void _adc_sync_enable_channel(struct _adc_sync_device *const device, const uint8_t channel);
+
+/**
+ * \brief Disable ADC
+ *
+ * \param[in] device   The pointer to ADC device instance
+ * \param[in] channel  Channel number
+ */
+void _adc_sync_disable_channel(struct _adc_sync_device *const device, const uint8_t channel);
+
+/**
+ * \brief Retrieve ADC conversion data size
+ *
+ * \param[in] device The pointer to ADC device instance
+ *
+ * \return The data size in bytes
+ */
+uint8_t _adc_sync_get_data_size(const struct _adc_sync_device *const device);
+
+/**
+ * \brief Check if conversion is done
+ *
+ * \param[in] device   The pointer to ADC device instance
+ * \param[in] channel  Channel number
+ *
+ * \return The status of conversion
+ * \retval true The conversion is done
+ * \retval false The conversion is not done
+ */
+bool _adc_sync_is_channel_conversion_done(const struct _adc_sync_device *const device, const uint8_t channel);
+
+/**
+ * \brief Make conversion
+ *
+ * \param[in] device The pointer to ADC device instance
+ */
+void _adc_sync_convert(struct _adc_sync_device *const device);
+
+/**
+ * \brief Retrieve the conversion result
+ *
+ * \param[in] device   The pointer to ADC device instance
+ * \param[in] channel  Channel number
+ *
+ * \return The result value of channel
+ */
+uint16_t _adc_sync_read_channel_data(const struct _adc_sync_device *const device, const uint8_t channel);
+
+/**
+ * \brief Set reference source
+ *
+ * \param[in] device The pointer to ADC device instance
+ * \param[in] reference A reference source to set
+ */
+void _adc_sync_set_reference_source(struct _adc_sync_device *const device, const adc_reference_t reference);
+
+/**
+ * \brief Set resolution
+ *
+ * \param[in] device The pointer to ADC device instance
+ * \param[in] resolution A resolution to set
+ */
+void _adc_sync_set_resolution(struct _adc_sync_device *const device, const adc_resolution_t resolution);
+
+/**
+ * \brief Set ADC input source of a channel
+ *
+ * \param[in] device    The pointer to ADC device instance
+ * \param[in] pos_input A positive input source to set
+ * \param[in] neg_input A negative input source to set
+ * \param[in] channel   Channel number
+ */
+void _adc_sync_set_inputs(struct _adc_sync_device *const device, const adc_pos_input_t pos_input,
+                          const adc_neg_input_t neg_input, const uint8_t channel);
+
+/**
+ * \brief Set conversion mode
+ *
+ * \param[in] device The pointer to ADC device instance
+ * \param[in] mode A conversion mode to set
+ */
+void _adc_sync_set_conversion_mode(struct _adc_sync_device *const device, const enum adc_conversion_mode mode);
+
+/**
+ * \brief Set differential mode
+ *
+ * \param[in] device  The pointer to ADC device instance
+ * \param[in] channel Channel number
+ * \param[in] mode    A differential mode to set
+ */
+void _adc_sync_set_channel_differential_mode(struct _adc_sync_device *const device, const uint8_t channel,
+                                             const enum adc_differential_mode mode);
+
+/**
+ * \brief Set gain
+ *
+ * \param[in] device   The pointer to ADC device instance
+ * \param[in] channel  Channel number
+ * \param[in] gain     A gain to set
+ */
+void _adc_sync_set_channel_gain(struct _adc_sync_device *const device, const uint8_t channel, const adc_gain_t gain);
+
+/**
+ * \brief Set window mode
+ *
+ * \param[in] device The pointer to ADC device instance
+ * \param[in] mode   A mode to set
+ */
+void _adc_sync_set_window_mode(struct _adc_sync_device *const device, const adc_window_mode_t mode);
+
+/**
+ * \brief Set threshold
+ *
+ * \param[in] device        The pointer to ADC device instance
+ * \param[in] low_threshold  A lower threshold to set
+ * \param[in] up_threshold   An upper thresholds to set
+ */
+void _adc_sync_set_thresholds(struct _adc_sync_device *const device, const adc_threshold_t low_threshold,
+                              const adc_threshold_t up_threshold);
+
+/**
+ * \brief Retrieve threshold state
+ *
+ * \param[in] device The pointer to ADC device instance
+ * \param[out] state The threshold state
+ */
+void _adc_sync_get_threshold_state(const struct _adc_sync_device *const device, adc_threshold_status_t *const state);
+//@}
+
+#ifdef __cplusplus
+}
+#endif
+/**@}*/
+#endif /* _HPL_ADC_SYNC_H_INCLUDED */
diff --git a/atmel-samd/asf4/samd21/hal/include/hpl_calendar.h b/atmel-samd/asf4/samd21/hal/include/hpl_calendar.h
new file mode 100644
index 000000000..9b9002c25
--- /dev/null
+++ b/atmel-samd/asf4/samd21/hal/include/hpl_calendar.h
@@ -0,0 +1,252 @@
+/**
+ * \file
+ *
+ * \brief Generic CALENDAR functionality declaration.
+ *
+ * Copyright (C) 2014-2016 Atmel Corporation. All rights reserved.
+ *
+ * \asf_license_start
+ *
+ * \page License
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright notice,
+ *    this list of conditions and the following disclaimer.
+ *
+ * 2. Redistributions in binary form must reproduce the above copyright notice,
+ *    this list of conditions and the following disclaimer in the documentation
+ *    and/or other materials provided with the distribution.
+ *
+ * 3. The name of Atmel may not be used to endorse or promote products derived
+ *    from this software without specific prior written permission.
+ *
+ * 4. This software may only be redistributed and used in connection with an
+ *    Atmel microcontroller product.
+ *
+ * THIS SOFTWARE IS PROVIDED BY ATMEL "AS IS" AND ANY EXPRESS OR IMPLIED
+ * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
+ * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT ARE
+ * EXPRESSLY AND SPECIFICALLY DISCLAIMED. IN NO EVENT SHALL ATMEL BE LIABLE FOR
+ * ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+ * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
+ * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
+ * ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+ * POSSIBILITY OF SUCH DAMAGE.
+ *
+ * \asf_license_stop
+ *
+ */
+#ifndef _HPL_CALENDER_H_INCLUDED
+#define _HPL_CALENDER_H_INCLUDED
+
+#include <compiler.h>
+#include <utils_list.h>
+#include "hpl_irq.h"
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+/**
+ * \brief Calendar structure
+ *
+ * The Calendar structure forward declaration.
+ */
+struct calendar_dev;
+
+/**
+ * \brief Available mask options for alarms.
+ *
+ * Available mask options for alarms.
+ */
+enum calendar_alarm_option {
+	/** Alarm disabled. */
+	CALENDAR_ALARM_MATCH_DISABLED = 0,
+	/** Alarm match on second. */
+	CALENDAR_ALARM_MATCH_SEC,
+	/** Alarm match on second and minute. */
+	CALENDAR_ALARM_MATCH_MIN,
+	/** Alarm match on second, minute, and hour. */
+	CALENDAR_ALARM_MATCH_HOUR,
+	/** Alarm match on second, minute, hour, and day. */
+	CALENDAR_ALARM_MATCH_DAY,
+	/** Alarm match on second, minute, hour, day, and month. */
+	CALENDAR_ALARM_MATCH_MONTH,
+	/** Alarm match on second, minute, hour, day, month and year. */
+	CALENDAR_ALARM_MATCH_YEAR
+};
+
+/**
+ * \brief Available mode for alarms.
+ */
+enum calendar_alarm_mode { ONESHOT = 1, REPEAT };
+/**
+ * \brief Prototype of callback on alarm match
+ */
+typedef void (*calendar_drv_cb_alarm_t)(struct calendar_dev *const dev);
+
+/**
+ * \brief Structure of Calendar instance
+ */
+struct calendar_dev {
+	/** Pointer to the hardware base */
+	void *hw;
+	/** Alarm match callback */
+	calendar_drv_cb_alarm_t callback;
+	/** IRQ struct */
+	struct _irq_descriptor irq;
+};
+
+/**
+ * \brief Time struct for calendar
+ */
+struct calendar_time {
+	/*range from 0 to 59*/
+	uint8_t sec;
+	/*range from 0 to 59*/
+	uint8_t min;
+	/*range from 0 to 23*/
+	uint8_t hour;
+};
+
+/**
+ * \brief Time struct for calendar
+ */
+struct calendar_date {
+	/*range from 1 to 28/29/30/31*/
+	uint8_t day;
+	/*range from 1 to 12*/
+	uint8_t month;
+	/*absolute year>= 1970(such as 2000)*/
+	uint16_t year;
+};
+
+/** \brief Calendar driver struct
+ *
+ */
+struct calendar_descriptor {
+	struct calendar_dev    device;
+	struct list_descriptor alarms;
+	/*base date/time = base_year/1/1/0/0/0(year/month/day/hour/min/sec)*/
+	uint32_t base_year;
+	uint8_t  flags;
+};
+
+/** \brief Date&Time struct for calendar
+ */
+struct calendar_date_time {
+	struct calendar_time time;
+	struct calendar_date date;
+};
+
+/** \brief struct for alarm time
+ */
+struct _calendar_alarm {
+	struct calendar_date_time  datetime;
+	uint32_t                   timestamp;
+	enum calendar_alarm_option option;
+	enum calendar_alarm_mode   mode;
+};
+
+/**
+ * \brief Initialize Calendar instance
+ *
+ * \param[in] dev The pointer to calendar device struct
+ *
+ * \return ERR_NONE on success, or an error code on failure.
+ */
+int32_t _calendar_init(struct calendar_dev *const dev);
+
+/**
+ * \brief Deinitialize Calendar instance
+ *
+ * \param[in] dev The pointer to calendar device struct
+ *
+ * \return ERR_NONE on success, or an error code on failure.
+ */
+int32_t _calendar_deinit(struct calendar_dev *const dev);
+
+/**
+ * \brief Enable Calendar instance
+ *
+ * \param[in] dev The pointer to calendar device struct
+ *
+ * \return ERR_NONE on success, or an error code on failure.
+ */
+int32_t _calendar_enable(struct calendar_dev *const dev);
+
+/**
+ * \brief Disable Calendar instance
+ *
+ * \param[in] dev The pointer to calendar device struct
+ *
+ * \return ERR_NONE on success, or an error code on failure.
+ */
+int32_t _calendar_disable(struct calendar_dev *const dev);
+/**
+ * \brief Set time for calendar
+ *
+ * \param[in] dev The pointer to calendar device struct
+ * \param[in] p_calendar_time Pointer to the time configuration
+ *
+ * \return ERR_NONE on success, or an error code on failure.
+ */
+int32_t _calendar_set_time(struct calendar_dev *const dev, struct calendar_time *const p_calendar_time);
+
+/**
+ * \brief Set date for calendar
+ *
+ * \param[in] dev The pointer to calendar device struct
+ * \param[in] p_calendar_date Pointer to the date configuration
+ *
+ * \return ERR_NONE on success, or an error code on failure.
+ */
+int32_t _calendar_set_date(struct calendar_dev *const dev, struct calendar_date *const p_calendar_date);
+
+/**
+ * \brief Get the time for calendar HAL instance and hardware
+ *  Retrieve the time from calendar instance.
+ *
+ * \param[in] dev The pointer to calendar device struct
+ * \param[in] date_time Pointer to value that will be filled with current time
+ *
+ * \return Return current counter value
+ */
+uint32_t _calendar_get_date_time(struct calendar_dev *const dev, struct calendar_date_time *const date_time);
+
+/**
+ * \brief Set compare value for calendar
+ *
+ * \param[in] dev The pointer to calendar device struct
+ * \param[in] alarm Pointer to the configuration
+ *
+ * \return ERR_NONE on success, or an error code on failure.
+ */
+int32_t _calendar_set_alarm(struct calendar_dev *const dev, struct _calendar_alarm *const alarm);
+
+/**
+ * \brief Register callback for calendar alarm
+ *
+ * \param[in] dev The pointer to calendar device struct
+ * \param[in] callback The pointer to callback function
+ *
+ * \return ERR_NONE on success, or an error code on failure.
+ */
+int32_t _calendar_register_callback(struct calendar_dev *const dev, calendar_drv_cb_alarm_t callback);
+
+/**
+ * \brief Set calendar IRQ
+ *
+ * \param[in] dev The pointer to calendar device struct
+ */
+void _calendar_set_irq(struct calendar_dev *const dev);
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif /* _HPL_RTC_H_INCLUDED */
diff --git a/atmel-samd/asf4/samd21/hal/include/hpl_core.h b/atmel-samd/asf4/samd21/hal/include/hpl_core.h
new file mode 100644
index 000000000..db448a16a
--- /dev/null
+++ b/atmel-samd/asf4/samd21/hal/include/hpl_core.h
@@ -0,0 +1,66 @@
+/**
+ * \file
+ *
+ * \brief CPU core related functionality declaration.
+ *
+ * Copyright (C) 2015 Atmel Corporation. All rights reserved.
+ *
+ * \asf_license_start
+ *
+ * \page License
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright notice,
+ *    this list of conditions and the following disclaimer.
+ *
+ * 2. Redistributions in binary form must reproduce the above copyright notice,
+ *    this list of conditions and the following disclaimer in the documentation
+ *    and/or other materials provided with the distribution.
+ *
+ * 3. The name of Atmel may not be used to endorse or promote products derived
+ *    from this software without specific prior written permission.
+ *
+ * 4. This software may only be redistributed and used in connection with an
+ *    Atmel microcontroller product.
+ *
+ * THIS SOFTWARE IS PROVIDED BY ATMEL "AS IS" AND ANY EXPRESS OR IMPLIED
+ * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
+ * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT ARE
+ * EXPRESSLY AND SPECIFICALLY DISCLAIMED. IN NO EVENT SHALL ATMEL BE LIABLE FOR
+ * ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+ * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
+ * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
+ * ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+ * POSSIBILITY OF SUCH DAMAGE.
+ *
+ * \asf_license_stop
+ *
+ */
+
+#ifndef _HPL_CORE_H_INCLUDED
+#define _HPL_CORE_H_INCLUDED
+
+/**
+ * \addtogroup HPL Core
+ *
+ * \section hpl_core_rev Revision History
+ * - v1.0.0 Initial Release
+ *
+ *@{
+ */
+
+#include "hpl_core_port.h"
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+#ifdef __cplusplus
+}
+#endif
+/**@}*/
+#endif /* _HPL_CORE_H_INCLUDED */
diff --git a/atmel-samd/asf4/samd21/hal/include/hpl_dac_async.h b/atmel-samd/asf4/samd21/hal/include/hpl_dac_async.h
new file mode 100644
index 000000000..fe55e6015
--- /dev/null
+++ b/atmel-samd/asf4/samd21/hal/include/hpl_dac_async.h
@@ -0,0 +1,182 @@
+/**
+ * \file
+ *
+ * \brief DAC related functionality declaration.
+ *
+ * Copyright (C) 2014-2015 Atmel Corporation. All rights reserved.
+ *
+ * \asf_license_start
+ *
+ * \page License
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright notice,
+ *    this list of conditions and the following disclaimer.
+ *
+ * 2. Redistributions in binary form must reproduce the above copyright notice,
+ *    this list of conditions and the following disclaimer in the documentation
+ *    and/or other materials provided with the distribution.
+ *
+ * 3. The name of Atmel may not be used to endorse or promote products derived
+ *    from this software without specific prior written permission.
+ *
+ * 4. This software may only be redistributed and used in connection with an
+ *    Atmel microcontroller product.
+ *
+ * THIS SOFTWARE IS PROVIDED BY ATMEL "AS IS" AND ANY EXPRESS OR IMPLIED
+ * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
+ * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT ARE
+ * EXPRESSLY AND SPECIFICALLY DISCLAIMED. IN NO EVENT SHALL ATMEL BE LIABLE FOR
+ * ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+ * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
+ * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
+ * ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+ * POSSIBILITY OF SUCH DAMAGE.
+ *
+ * \asf_license_stop
+ *
+ */
+#ifndef _HPL_DAC_H_INCLUDED
+#define _HPL_DAC_H_INCLUDED
+
+/**
+ * \addtogroup hpl__dac__group DAC HPL APIs
+ * See interface description here: \ref hpl__dac__doc
+ *
+ */
+
+/**@{*/
+
+#include <compiler.h>
+#include "hpl_irq.h"
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+/**
+ * DAC hardware Channel Number
+ */
+
+#ifndef CHANNEL_NUM
+#define CHANNEL_NUM 1
+#endif
+
+/**
+ * \brief DAC callback types
+ */
+enum _dac_callback_type { DAC_DEVICE_CONVERSION_DONE_CB, DAC_DEVICE_ERROR_CB };
+
+/**
+ * \brief DAC device structure
+ *
+ * The DAC device structure forward declaration.
+ */
+struct _dac_async_device;
+
+/**
+ * \brief DAC interrupt handlers structure
+ */
+struct _dac_callback {
+	/** Transmit ready(Data Buffer empty) handler */
+	void (*tx_ready_cb)(struct _dac_async_device *device, const uint8_t ch);
+	/** Error handler */
+	void (*tx_error_cb)(struct _dac_async_device *device, const uint8_t ch);
+};
+
+/**
+ * \brief DAC descriptor device structure.
+ */
+struct _dac_async_device {
+	struct _dac_callback   dac_cb; /*!< Interrupt handers  */
+	struct _irq_descriptor irq;    /*!< Interrupt descriptor */
+	void *                 hw;     /*!< Hardware module instance handler */
+};
+
+/**
+ * \brief Initialize asynchronous DAC.
+ *
+ * This function does low level DAC configuration.
+ *
+ * \param[in] device The pointer to DAC device instance
+ * \param[in] hw The pointer to hardware instance
+ *
+ * \return Initialization status
+ */
+int32_t _dac_async_init(struct _dac_async_device *const device, void *const hw);
+
+/**
+ * \brief Deinitialize DAC.
+ *
+ * \param[in] device The pointer to DAC device instance
+ */
+void _dac_async_deinit(struct _dac_async_device *const device);
+
+/**
+ * \brief Enable DAC Channel.
+ *
+ * \param[in] device The pointer to DAC device instance
+ * \param[in] ch  channel number
+ */
+void _dac_async_enable_channel(struct _dac_async_device *const device, const uint8_t ch);
+
+/**
+ * \brief Disable DAC Channel.
+ *
+ * \param[in] device The pointer to DAC device instance
+ * \param[in] ch  channel number
+ */
+void _dac_async_disable_channel(struct _dac_async_device *const device, const uint8_t ch);
+
+/**
+ * \brief Checks if DAC channel is enabled
+ *
+ * \param[in] device The pointer to DAC device instance
+ * \param[in] ch  channel number
+ *
+ * \return true channel is enabled, false otherwise
+ */
+bool _dac_async_is_channel_enable(struct _dac_async_device *const device, const uint8_t ch);
+
+/**
+ * \brief Write DAC data for output.
+ *
+ * \param[in] device The pointer to DAC device instance
+ * \param[in] data Digital data which to be converted
+ * \param[in] ch The channel selected to output
+ */
+void _dac_async_write_data(struct _dac_async_device *const device, const uint16_t data, const uint8_t ch);
+
+/**
+ * \brief Enable/disable DAC interrupt
+ *
+ * param[in] device The pointer to DAC device instance
+ * param[in] type The type of interrupt to disable/enable if applicable
+ * param[in] state Enable or disable
+ */
+void _dac_async_set_irq_state(struct _dac_async_device *const device, const enum _dac_callback_type type,
+                              const bool state);
+
+#ifdef __cplusplus
+}
+#endif
+
+/**@}*/
+
+/**
+ * \page hpl__dac__doc DAC HPL Interface Driver
+ *
+ * \section hpl__dac__desc DAC HPL Description
+ *
+ * The following device can use this HPL driver
+ * - Atmel | SMART SAM D21
+ *
+ * \section hpl__dac__imple DAC HPL Implements
+ * - \subpage hpl__dac__hw_module1__doc
+ */
+
+#endif /* _HPL_DAC_H_INCLUDED */
diff --git a/atmel-samd/asf4/samd21/hal/include/hpl_dac_sync.h b/atmel-samd/asf4/samd21/hal/include/hpl_dac_sync.h
new file mode 100644
index 000000000..49a7222bf
--- /dev/null
+++ b/atmel-samd/asf4/samd21/hal/include/hpl_dac_sync.h
@@ -0,0 +1,148 @@
+/**
+ * \file
+ *
+ * \brief DAC related functionality declaration.
+ *
+ * Copyright (C) 2014-2015 Atmel Corporation. All rights reserved.
+ *
+ * \asf_license_start
+ *
+ * \page License
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright notice,
+ *    this list of conditions and the following disclaimer.
+ *
+ * 2. Redistributions in binary form must reproduce the above copyright notice,
+ *    this list of conditions and the following disclaimer in the documentation
+ *    and/or other materials provided with the distribution.
+ *
+ * 3. The name of Atmel may not be used to endorse or promote products derived
+ *    from this software without specific prior written permission.
+ *
+ * 4. This software may only be redistributed and used in connection with an
+ *    Atmel microcontroller product.
+ *
+ * THIS SOFTWARE IS PROVIDED BY ATMEL "AS IS" AND ANY EXPRESS OR IMPLIED
+ * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
+ * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT ARE
+ * EXPRESSLY AND SPECIFICALLY DISCLAIMED. IN NO EVENT SHALL ATMEL BE LIABLE FOR
+ * ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+ * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
+ * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
+ * ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+ * POSSIBILITY OF SUCH DAMAGE.
+ *
+ * \asf_license_stop
+ *
+ */
+#ifndef _HPL_DAC_SYNC_H_INCLUDED
+#define _HPL_DAC_SYNC_H_INCLUDED
+
+/**
+ * \addtogroup hpl__dac__group DAC HPL APIs
+ * See interface description here: \ref hpl__dac__doc
+ *
+ */
+
+/**@{*/
+
+#include <compiler.h>
+#include "hpl_irq.h"
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+/**
+ * DAC hardware Channel Number
+ */
+
+#ifndef CHANNEL_NUM
+#define CHANNEL_NUM 1
+#endif
+
+/**
+ * \brief DAC sync descriptor device structure.
+ */
+struct _dac_sync_device {
+	void *hw; /*!< Hardware module instance handler */
+};
+
+/**
+ * \brief Initialize synchronous DAC.
+ *
+ * This function does low level DAC configuration.
+ *
+ * \param[in] device The pointer to DAC device instance
+ * \param[in] hw The pointer to hardware instance
+ *
+ * \return Initialization status
+ */
+int32_t _dac_sync_init(struct _dac_sync_device *const device, void *const hw);
+
+/**
+ * \brief Deinitialize DAC.
+ *
+ * \param[in] device The pointer to DAC device instance
+ */
+void _dac_sync_deinit(struct _dac_sync_device *const device);
+
+/**
+ * \brief Enable DAC Channel.
+ *
+ * \param[in] device The pointer to DAC device instance
+ * \param[in] ch  channel number
+ */
+void _dac_sync_enable_channel(struct _dac_sync_device *const device, const uint8_t ch);
+
+/**
+ * \brief Disable DAC Channel.
+ *
+ * \param[in] device The pointer to DAC device instance
+ * \param[in] ch  channel number
+ */
+void _dac_sync_disable_channel(struct _dac_sync_device *const device, const uint8_t ch);
+
+/**
+ * \brief Checks if DAC channel is enabled
+ *
+ * \param[in] device The pointer to DAC device instance
+ * \param[in] ch  channel number
+ *
+ * \return true channel is enabled, false otherwise
+ */
+bool _dac_sync_is_channel_enable(struct _dac_sync_device *const device, const uint8_t ch);
+
+/**
+ * \brief Write synchronous DAC data for output.
+ *
+ * \param[in] device The pointer to DAC device instance
+ * \param[in] data Digital data which to be converted
+ * \param[in] ch The channel selected to output
+ */
+void _dac_sync_write_data(struct _dac_sync_device *const device, const uint16_t data, const uint8_t ch);
+
+#ifdef __cplusplus
+}
+#endif
+
+/**@}*/
+
+/**
+ * \page hpl__dac__doc DAC HPL Interface Driver
+ *
+ * \section hpl__dac__desc DAC HPL Description
+ *
+ * The following device can use this HPL driver
+ * - Atmel | SMART SAM D21
+ *
+ * \section hpl__dac__imple DAC HPL Implements
+ * - \subpage hpl__dac__hw_module1__doc
+ */
+
+#endif /* _HPL_DAC_SYNC_H_INCLUDED */
diff --git a/atmel-samd/asf4/samd21/hal/include/hpl_delay.h b/atmel-samd/asf4/samd21/hal/include/hpl_delay.h
new file mode 100644
index 000000000..7d2a6f90b
--- /dev/null
+++ b/atmel-samd/asf4/samd21/hal/include/hpl_delay.h
@@ -0,0 +1,88 @@
+/**
+ * \file
+ *
+ * \brief Delay related functionality declaration.
+ *
+ * Copyright (C) 2014 Atmel Corporation. All rights reserved.
+ *
+ * \asf_license_start
+ *
+ * \page License
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are met:
+ *
+ * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
+ * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
+ * ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+ * POSSIBILITY OF SUCH DAMAGE.
+ *
+ * \asf_license_stop
+ *
+ */
+
+#ifndef _HPL_DELAY_H_INCLUDED
+#define _HPL_DELAY_H_INCLUDED
+
+/**
+ * \addtogroup HPL Delay
+ *
+ * \section hpl_delay_rev Revision History
+ * - v1.0.0 Initial Release
+ *
+ *@{
+ */
+
+#ifndef _UNIT_TEST_
+#include <compiler.h>
+#endif
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+/**
+ * \name HPL functions
+ */
+//@{
+
+/**
+ * \brief Initialize delay functionality
+ *
+ * \param[in] hw The pointer to hardware instance
+ */
+void _delay_init(void *const hw);
+
+/**
+ * \brief Retrieve the amount of cycles to delay for the given amount of us
+ *
+ * \param[in] us The amount of us to delay for
+ *
+ * \return The amount of cycles
+ */
+uint32_t _get_cycles_for_us(const uint16_t us);
+
+/**
+ * \brief Retrieve the amount of cycles to delay for the given amount of ms
+ *
+ * \param[in] ms The amount of ms to delay for
+ *
+ * \return The amount of cycles
+ */
+uint32_t _get_cycles_for_ms(const uint16_t ms);
+
+/**
+ * \brief Delay loop to delay n number of cycles
+ *
+ * \param[in] hw The pointer to hardware instance
+ * \param[in] cycles The amount of cycles to delay for
+ */
+void _delay_cycles(void *const hw, uint32_t cycles);
+//@}
+
+#ifdef __cplusplus
+}
+#endif
+/**@}*/
+#endif /* _HPL_DELAY_H_INCLUDED */
diff --git a/atmel-samd/asf4/samd21/hal/include/hpl_dma.h b/atmel-samd/asf4/samd21/hal/include/hpl_dma.h
new file mode 100644
index 000000000..f8c8cce42
--- /dev/null
+++ b/atmel-samd/asf4/samd21/hal/include/hpl_dma.h
@@ -0,0 +1,167 @@
+/**
+ * \file
+ *
+ * \brief DMA related functionality declaration.
+ *
+ * Copyright (C) 2015 Atmel Corporation. All rights reserved.
+ *
+ * \asf_license_start
+ *
+ * \page License
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright notice,
+ *    this list of conditions and the following disclaimer.
+ *
+ * 2. Redistributions in binary form must reproduce the above copyright notice,
+ *    this list of conditions and the following disclaimer in the documentation
+ *    and/or other materials provided with the distribution.
+ *
+ * 3. The name of Atmel may not be used to endorse or promote products derived
+ *    from this software without specific prior written permission.
+ *
+ * 4. This software may only be redistributed and used in connection with an
+ *    Atmel microcontroller product.
+ *
+ * THIS SOFTWARE IS PROVIDED BY ATMEL "AS IS" AND ANY EXPRESS OR IMPLIED
+ * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
+ * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT ARE
+ * EXPRESSLY AND SPECIFICALLY DISCLAIMED. IN NO EVENT SHALL ATMEL BE LIABLE FOR
+ * ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+ * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
+ * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
+ * ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+ * POSSIBILITY OF SUCH DAMAGE.
+ *
+ * \asf_license_stop
+ *
+ */
+
+#ifndef _HPL_DMA_H_INCLUDED
+#define _HPL_DMA_H_INCLUDED
+
+/**
+ * \addtogroup HPL DMA
+ *
+ * \section hpl_dma_rev Revision History
+ * - v1.0.0 Initial Release
+ *
+ *@{
+ */
+
+#include <compiler.h>
+#include <hpl_irq.h>
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+struct _dma_resource;
+
+/**
+ * \brief DMA callback types
+ */
+enum _dma_callback_type { DMA_TRANSFER_COMPLETE_CB, DMA_TRANSFER_ERROR_CB };
+
+/**
+ * \brief DMA interrupt callbacks
+ */
+struct _dma_callbacks {
+	void (*transfer_done)(struct _dma_resource *resource);
+	void (*error)(struct _dma_resource *resource);
+};
+
+/**
+ * \brief DMA resource structure
+ */
+struct _dma_resource {
+	struct _dma_callbacks dma_cb;
+	void *                back;
+};
+
+/**
+ * \brief Initialize DMA
+ *
+ * This function does low level DMA configuration.
+ *
+ * \return initialize status
+ */
+int32_t _dma_init(void);
+
+/**
+ * \brief Set destination address
+ *
+ * \param[in] channel DMA channel to set destination address for
+ * \param[in] dst Destination address
+ *
+ * \return setting status
+ */
+int32_t _dma_set_destination_address(const uint8_t channel, const void *const dst);
+
+/**
+ * \brief Set source address
+ *
+ * \param[in] channel DMA channel to set source address for
+ * \param[in] src Source address
+ *
+ * \return setting status
+ */
+int32_t _dma_set_source_address(const uint8_t channel, const void *const src);
+
+/**
+ * \brief Enable/disable source address incrementation during DMA transaction
+ *
+ * \param[in] channel DMA channel to set source address for
+ * \param[in] enable True to enable, false to disable
+ *
+ * \return status of operation
+ */
+int32_t _dma_srcinc_enable(const uint8_t channel, const bool enable);
+
+/**
+ * \brief Set the amount of data to be transfered per transaction
+ *
+ * \param[in] channel DMA channel to set data amount for
+ * \param[in] amount Data amount
+ *
+ * \return status of operation
+ */
+int32_t _dma_set_data_amount(const uint8_t channel, const uint32_t amount);
+
+/**
+ * \brief Trigger DMA transaction on the given channel
+ *
+ * \param[in] channel DMA channel to trigger transaction on
+ *
+ * \return status of operation
+ */
+int32_t _dma_enable_transaction(const uint8_t channel, const bool software_trigger);
+
+/**
+ * \brief Retrieves DMA resource structure
+ *
+ * \param[out] resource The resource to be retrieved
+ * \param[in] channel DMA channel to retrieve structure for
+ *
+ * \return status of operation
+ */
+int32_t _dma_get_channel_resource(struct _dma_resource **resource, const uint8_t channel);
+
+/**
+ * \brief Enable/disable DMA interrupt
+ *
+ * \param[in] channel DMA channel to enable/disable interrupt for
+ * \param[in] type The type of interrupt to disable/enable if applicable
+ * \param[in] state Enable or disable
+ */
+void _dma_set_irq_state(const uint8_t channel, const enum _dma_callback_type type, const bool state);
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif /* HPL_DMA_H_INCLUDED */
diff --git a/atmel-samd/asf4/samd21/hal/include/hpl_flash.h b/atmel-samd/asf4/samd21/hal/include/hpl_flash.h
new file mode 100644
index 000000000..774bb5e0b
--- /dev/null
+++ b/atmel-samd/asf4/samd21/hal/include/hpl_flash.h
@@ -0,0 +1,228 @@
+/**
+ * \file
+ *
+ * \brief FLASH related functionality declaration.
+ *
+ * Copyright (C) 2015 Atmel Corporation. All rights reserved.
+ *
+ * \asf_license_start
+ *
+ * \page License
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright notice,
+ *    this list of conditions and the following disclaimer.
+ *
+ * 2. Redistributions in binary form must reproduce the above copyright notice,
+ *    this list of conditions and the following disclaimer in the documentation
+ *    and/or other materials provided with the distribution.
+ *
+ * 3. The name of Atmel may not be used to endorse or promote products derived
+ *    from this software without specific prior written permission.
+ *
+ * 4. This software may only be redistributed and used in connection with an
+ *    Atmel microcontroller product.
+ *
+ * THIS SOFTWARE IS PROVIDED BY ATMEL "AS IS" AND ANY EXPRESS OR IMPLIED
+ * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
+ * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT ARE
+ * EXPRESSLY AND SPECIFICALLY DISCLAIMED. IN NO EVENT SHALL ATMEL BE LIABLE FOR
+ * ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+ * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
+ * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
+ * ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+ * POSSIBILITY OF SUCH DAMAGE.
+ *
+ * \asf_license_stop
+ *
+ */
+#ifndef _HPL_FLASH_H_INCLUDED
+#define _HPL_FLASH_H_INCLUDED
+
+/**
+ * \addtogroup hpl__flash__group FLASH HPL APIs
+ *
+ */
+
+/**@{*/
+
+#include <compiler.h>
+#include "hpl_irq.h"
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+/**
+ * \brief FLASH device structure
+ *
+ * The FLASH device structure forward declaration.
+ */
+struct _flash_device;
+
+/** The callback types */
+enum _flash_cb_type { FLASH_DEVICE_CB_READY, FLASH_DEVICE_CB_ERROR, FLASH_DEVICE_CB_N };
+
+/**
+ * \brief FLASH interrupt handlers structure
+ */
+struct _flash_callback {
+	/** Ready to accept new command handler */
+	void (*ready_cb)(struct _flash_device *device);
+	/** Error handler */
+	void (*error_cb)(struct _flash_device *device);
+};
+
+/**
+ * \brief FLASH descriptor device structure.
+ */
+struct _flash_device {
+	struct _flash_callback flash_cb; /*!< Interrupt handers  */
+	struct _irq_descriptor irq;      /*!< Interrupt descriptor */
+	void *                 hw;       /*!< Hardware module instance handler */
+};
+
+/**
+ * \brief Initialize FLASH.
+ *
+ * This function does low level FLASH configuration.
+ *
+ * \param[in] device The pointer to FLASH device instance
+ * \param[in] hw The pointer to hardware instance
+ *
+ * \return Initialize status.
+ */
+int32_t _flash_init(struct _flash_device *const device, void *const hw);
+
+/**
+ * \brief Deinitialize FLASH.
+ *
+ * \param[in] device The pointer to FLASH device instance
+ */
+void _flash_deinit(struct _flash_device *const device);
+
+/**
+ * \brief Reads a number of bytes in the internal Flash.
+ *
+ * \param[in] device         The pointer to FLASH device instance
+ * \param[in]  src_addr      Source bytes address to read from flash
+ * \param[out] buffer        Pointer to a buffer where the content
+ *                           of the read page will be stored
+ * \param[in]  length        Number of bytes to read
+ */
+void _flash_read(struct _flash_device *const device, const uint32_t src_addr, uint8_t *buffer, uint32_t length);
+
+/**
+ * \brief Writes a number of bytes in the internal Flash.
+ *
+ * \param[in] device         The pointer to FLASH device instance
+ * \param[in]  dst_addr      Destination bytes address to write into flash
+ * \param[in]  buffer        Pointer to buffer where the data to
+ *                           write is stored
+ * \param[in]  length        Number of bytes to write
+ */
+void _flash_write(struct _flash_device *const device, const uint32_t dst_addr, uint8_t *buffer, uint32_t length);
+
+/**
+ * \brief Appends a number of bytes in the internal Flash.
+ *
+ * \param[in] device         The pointer to FLASH device instance
+ * \param[in]  dst_addr      Destination bytes address to write into flash
+ * \param[in]  buffer        Pointer to buffer with data to write to flash
+ * \param[in]  length        Number of bytes to write
+ */
+void _flash_append(struct _flash_device *const device, const uint32_t dst_addr, uint8_t *buffer, uint32_t length);
+
+/** \brief Execute lock in the internal flash
+ *  \param[in] device         The pointer to FLASH device instance
+ *  \param[in]  dst_addr      Destination bytes address aligned with page
+ *                            start to be locked
+ *  \param[in]  page_nums     Number of pages to be locked
+ *
+ *  \return Real locked numbers of pages.
+ */
+int32_t _flash_lock(struct _flash_device *const device, const uint32_t dst_addr, uint32_t page_nums);
+
+/** \brief Execute unlock in the internal flash
+ *  \param[in] device         The pointer to FLASH device instance
+ *  \param[in]  dst_addr      Destination bytes address aligned with page
+ *                            start to be unlocked
+ *  \param[in]  page_nums     Number of pages to be unlocked
+ *
+ *  \return Real unlocked numbers of pages.
+ */
+int32_t _flash_unlock(struct _flash_device *const device, const uint32_t dst_addr, uint32_t page_nums);
+
+/** \brief check whether the region which is pointed by address
+ *         is locked
+ *  \param[in] device         The pointer to FLASH device instance
+ *  \param[in]  dst_addr      Destination bytes address to check
+ *
+ *  \return The lock status of assigned address.
+ */
+bool _flash_is_locked(struct _flash_device *const device, const uint32_t dst_addr);
+
+/** \brief Execute erase in the internal flash
+ *  \param[in] device         The pointer to FLASH device instance
+ *  \param[in]  dst_addr      Destination bytes address aligned with page
+ *                            start to be erased
+ *  \param[in]  page_nums     Number of pages to be erased
+ */
+void _flash_erase(struct _flash_device *const device, const uint32_t dst_addr, uint32_t page_nums);
+
+/**
+ * \brief Get the flash page size.
+ *
+ * \param[in] device         The pointer to FLASH device instance
+ *
+ * \return The flash page size
+ */
+uint32_t _flash_get_page_size(struct _flash_device *const device);
+
+/**
+ * \brief Get the numbers of flash page.
+ *
+ * \param[in] device         The pointer to FLASH device instance
+ *
+ * \return The flash total page numbers
+ */
+uint32_t _flash_get_total_pages(struct _flash_device *const device);
+
+/**
+ * \brief Get the number of wait states for read and write operations.
+ *
+ * \param[in] device         The pointer to FLASH device instance
+ *
+ * \return The number of wait states for read and write operations
+ */
+uint8_t _flash_get_wait_state(struct _flash_device *const device);
+
+/**
+ * \brief Set the number of wait states for read and write operations.
+ *
+ * \param[in] device         The pointer to FLASH device instance
+ * \param[in] state The number of wait states
+ *
+ */
+void _flash_set_wait_state(struct _flash_device *const device, uint8_t state);
+
+/**
+ * \brief Enable/disable Flash interrupt
+ *
+ * param[in] device The pointer to Flash device instance
+ * param[in] type The type of interrupt to disable/enable if applicable
+ * param[in] state Enable or disable
+ */
+void _flash_set_irq_state(struct _flash_device *const device, const enum _flash_cb_type type, const bool state);
+
+#ifdef __cplusplus
+}
+#endif
+
+/**@}*/
+
+#endif /* _HPL_FLASH_H_INCLUDED */
diff --git a/atmel-samd/asf4/samd21/hal/include/hpl_gpio.h b/atmel-samd/asf4/samd21/hal/include/hpl_gpio.h
new file mode 100644
index 000000000..e1de9c58e
--- /dev/null
+++ b/atmel-samd/asf4/samd21/hal/include/hpl_gpio.h
@@ -0,0 +1,195 @@
+/**
+ * \file
+ *
+ * \brief Port related functionality declaration.
+ *
+ * Copyright (C) 2014-2016 Atmel Corporation. All rights reserved.
+ *
+ * \asf_license_start
+ *
+ * \page License
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright notice,
+ *    this list of conditions and the following disclaimer.
+ *
+ * 2. Redistributions in binary form must reproduce the above copyright notice,
+ *    this list of conditions and the following disclaimer in the documentation
+ *    and/or other materials provided with the distribution.
+ *
+ * 3. The name of Atmel may not be used to endorse or promote products derived
+ *    from this software without specific prior written permission.
+ *
+ * 4. This software may only be redistributed and used in connection with an
+ *    Atmel microcontroller product.
+ *
+ * THIS SOFTWARE IS PROVIDED BY ATMEL "AS IS" AND ANY EXPRESS OR IMPLIED
+ * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
+ * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT ARE
+ * EXPRESSLY AND SPECIFICALLY DISCLAIMED. IN NO EVENT SHALL ATMEL BE LIABLE FOR
+ * ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+ * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
+ * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
+ * ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+ * POSSIBILITY OF SUCH DAMAGE.
+ *
+ * \asf_license_stop
+ *
+ */
+
+#ifndef _HPL_GPIO_H_INCLUDED
+#define _HPL_GPIO_H_INCLUDED
+
+/**
+ * \addtogroup HPL Port
+ *
+ * \section hpl_port_rev Revision History
+ * - v1.0.0 Initial Release
+ *
+ *@{
+ */
+
+#include <compiler.h>
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+/**
+ * \brief Macros for the pin and port group, lower 5
+ * bits stands for pin number in the group, higher 3
+ * bits stands for port group
+ */
+#define GPIO_PIN(n) (((n)&0x1Fu) << 0)
+#define GPIO_PORT(n) ((n) >> 5)
+#define GPIO(port, pin) ((((port)&0x7u) << 5) + ((pin)&0x1Fu))
+#define GPIO_PIN_FUNCTION_OFF 0xffffffff
+
+/**
+ * \brief PORT pull mode settings
+ */
+enum gpio_pull_mode { GPIO_PULL_OFF, GPIO_PULL_UP, GPIO_PULL_DOWN };
+
+/**
+ * \brief PORT direction settins
+ */
+enum gpio_direction { GPIO_DIRECTION_OFF, GPIO_DIRECTION_IN, GPIO_DIRECTION_OUT };
+
+/**
+ * \brief PORT group abstraction
+ */
+
+enum gpio_port { GPIO_PORTA, GPIO_PORTB, GPIO_PORTC, GPIO_PORTD, GPIO_PORTE };
+
+/**
+ * \name HPL functions
+ */
+//@{
+/**
+ * \brief Port initialization function
+ *
+ * Port initialization function should setup the port module based
+ * on a static configuration file, this function should normally
+ * not be called directly, but is a part of hal_init()
+ */
+void _gpio_init(void);
+
+/**
+ * \brief Set direction on port with mask
+ *
+ * Set data direction for each pin, or disable the pin
+ *
+ * \param[in] port      Ports are grouped into groups of maximum 32 pins,
+ *                      GPIO_PORTA = group 0, GPIO_PORTB = group 1, etc
+ * \param[in] mask      Bit mask where 1 means apply direction setting to the
+ *                      corresponding pin
+ * \param[in] direction GPIO_DIRECTION_OFF  = set pin direction to input
+ *                      and disable input buffer to disable the pin
+ *                      GPIO_DIRECTION_IN   = set pin direction to input
+ *                      and enable input buffer to enable the pin
+ *                      GPIO_DIRECTION_OUT  = set pin direction to output
+ *                      and disable input buffer
+ */
+static inline void _gpio_set_direction(const enum gpio_port port, const uint32_t mask,
+                                       const enum gpio_direction direction);
+
+/**
+ * \brief Set output level on port with mask
+ *
+ * Sets output state on pin to high or low with pin masking
+ *
+ * \param[in] port  Ports are grouped into groups of maximum 32 pins,
+ *                  GPIO_PORTA = group 0, GPIO_PORTB = group 1, etc
+ * \param[in] mask  Bit mask where 1 means apply direction setting to
+ *                  the corresponding pin
+ * \param[in] level true  = pin level is set to 1
+ *                  false = pin level is set to 0
+ */
+static inline void _gpio_set_level(const enum gpio_port port, const uint32_t mask, const bool level);
+
+/**
+ * \brief Change output level to the opposite with mask
+ *
+ * Change pin output level to the opposite with pin masking
+ *
+ * \param[in] port  Ports are grouped into groups of maximum 32 pins,
+ *                  GPIO_PORTA = group 0, GPIO_PORTB = group 1, etc
+ * \param[in] mask  Bit mask where 1 means apply direction setting to
+ *                  the corresponding pin
+ */
+static inline void _gpio_toggle_level(const enum gpio_port port, const uint32_t mask);
+
+/**
+ * \brief Get input levels on all port pins
+ *
+ * Get input level on all port pins, will read IN register if configured to
+ * input and OUT register if configured as output
+ *
+ * \param[in] port  Ports are grouped into groups of maximum 32 pins,
+ *                  GPIO_PORTA = group 0, GPIO_PORTB = group 1, etc
+ */
+static inline uint32_t _gpio_get_level(const enum gpio_port port);
+
+/**
+ * \brief Set pin pull mode
+ *
+ * Set pull mode on a single pin
+ *
+ * \notice This function will automatically change pin direction to input
+ *
+ * \param[in] port      Ports are grouped into groups of maximum 32 pins,
+ *                      GPIO_PORTA = group 0, GPIO_PORTB = group 1, etc
+ * \param[in] pin       The pin in the group that pull mode should be selected
+ *                      for
+ * \param[in] pull_mode GPIO_PULL_OFF  = pull resistor on pin is disabled
+ *                      GPIO_PULL_DOWN = pull resistor on pin will pull pin
+ *                      level to ground level
+ *                      GPIO_PULL_UP   = pull resistor on pin will pull pin
+ *                      level to VCC
+ */
+static inline void _gpio_set_pin_pull_mode(const enum gpio_port port, const uint8_t pin,
+                                           const enum gpio_pull_mode pull_mode);
+
+/**
+ * \brief Set gpio function
+ *
+ * Select which function a gpio is used for
+ *
+ * \param[in] gpio     The gpio to set function for
+ * \param[in] function The gpio function is given by a 32-bit wide bitfield
+ *                     found in the header files for the device
+ *
+ */
+static inline void _gpio_set_pin_function(const uint32_t gpio, const uint32_t function);
+
+#include <hpl_gpio_base.h>
+//@}
+
+#ifdef __cplusplus
+}
+#endif
+/**@}*/
+#endif /* _HPL_GPIO_H_INCLUDED */
diff --git a/atmel-samd/asf4/samd21/hal/include/hpl_i2c_m_async.h b/atmel-samd/asf4/samd21/hal/include/hpl_i2c_m_async.h
new file mode 100644
index 000000000..c00d7e733
--- /dev/null
+++ b/atmel-samd/asf4/samd21/hal/include/hpl_i2c_m_async.h
@@ -0,0 +1,215 @@
+/**
+ * \file
+ *
+ * \brief I2C Master Hardware Proxy Layer(HPL) declaration.
+ *
+ * Copyright (C) 2015 Atmel Corporation. All rights reserved.
+ *
+ * \asf_license_start
+ *
+ * \page License
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright notice,
+ *    this list of conditions and the following disclaimer.
+ *
+ * 2. Redistributions in binary form must reproduce the above copyright notice,
+ *    this list of conditions and the following disclaimer in the documentation
+ *    and/or other materials provided with the distribution.
+ *
+ * 3. The name of Atmel may not be used to endorse or promote products derived
+ *    from this software without specific prior written permission.
+ *
+ * 4. This software may only be redistributed and used in connection with an
+ *    Atmel microcontroller product.
+ *
+ * THIS SOFTWARE IS PROVIDED BY ATMEL "AS IS" AND ANY EXPRESS OR IMPLIED
+ * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
+ * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT ARE
+ * EXPRESSLY AND SPECIFICALLY DISCLAIMED. IN NO EVENT SHALL ATMEL BE LIABLE FOR
+ * ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+ * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
+ * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
+ * ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+ * POSSIBILITY OF SUCH DAMAGE.
+ *
+ * \asf_license_stop
+ *
+ */
+#ifndef _HPL_I2C_M_ASYNC_H_INCLUDED
+#define _HPL_I2C_M_ASYNC_H_INCLUDED
+
+#include "hpl_i2c_m_sync.h"
+#include "hpl_irq.h"
+#include "utils.h"
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+/**
+ * \brief i2c master callback names
+ */
+enum _i2c_m_async_callback_type {
+	I2C_M_ASYNC_DEVICE_ERROR,
+	I2C_M_ASYNC_DEVICE_TX_COMPLETE,
+	I2C_M_ASYNC_DEVICE_RX_COMPLETE
+};
+
+struct _i2c_m_async_device;
+
+typedef void (*_i2c_complete_cb_t)(struct _i2c_m_async_device *i2c_dev);
+typedef void (*_i2c_error_cb_t)(struct _i2c_m_async_device *i2c_dev, int32_t errcode);
+
+/**
+ * \brief i2c callback pointers structure
+ */
+struct _i2c_m_async_callback {
+	_i2c_error_cb_t    error;
+	_i2c_complete_cb_t tx_complete;
+	_i2c_complete_cb_t rx_complete;
+};
+
+/**
+ * \brief i2c device structure
+ */
+struct _i2c_m_async_device {
+	struct _i2c_m_service        service;
+	void *                       hw;
+	struct _i2c_m_async_callback cb;
+	struct _irq_descriptor       irq;
+};
+
+/**
+ * \name HPL functions
+ */
+
+/**
+ * \brief Initialize I2C in interrupt mode
+ *
+ * This function does low level I2C configuration.
+ *
+ * \param[in] i2c_dev The pointer to i2c interrupt device structure
+ * \param[in] hw The pointer to hardware instance
+ *
+ * \return Return 0 for success and negative value for error
+ */
+int32_t _i2c_m_async_init(struct _i2c_m_async_device *const i2c_dev, void *const hw);
+
+/**
+ * \brief Deinitialize I2C in interrupt mode
+ *
+ * \param[in] i2c_dev The pointer to i2c device structure
+ *
+ * \return Return 0 for success and negative value for error
+ */
+int32_t _i2c_m_async_deinit(struct _i2c_m_async_device *const i2c_dev);
+
+/**
+ * \brief Enable I2C module
+ *
+ * This function does low level I2C enable.
+ *
+ * \param[in] i2c_dev The pointer to i2c device structure
+ *
+ * \return Return 0 for success and negative value for error
+ */
+int32_t _i2c_m_async_enable(struct _i2c_m_async_device *const i2c_dev);
+
+/**
+ * \brief Disable I2C module
+ *
+ * This function does low level I2C disable.
+ *
+ * \param[in] i2c_dev The pointer to i2c device structure
+ *
+ * \return Return 0 for success and negative value for error
+ */
+int32_t _i2c_m_async_disable(struct _i2c_m_async_device *const i2c_dev);
+
+/**
+ * \brief Transfer data by I2C
+ *
+ * This function does low level I2C data transfer.
+ *
+ * \param[in] i2c_dev The pointer to i2c device structure
+ * \param[in] msg The pointer to i2c msg structure
+ *
+ * \return Return 0 for success and negative value for error
+ */
+int32_t _i2c_m_async_transfer(struct _i2c_m_async_device *const i2c_dev, struct _i2c_m_msg *msg);
+
+/**
+ * \brief Set baud rate of I2C
+ *
+ * This function does low level I2C set baud rate.
+ *
+ * \param[in] i2c_dev The pointer to i2c device structure
+ * \param[in] clkrate The clock rate(KHz) input to i2c module
+ * \param[in] baudrate The demand baud rate(KHz) of i2c module
+ *
+ * \return Return 0 for success and negative value for error
+ */
+int32_t _i2c_m_async_set_baudrate(struct _i2c_m_async_device *const i2c_dev, uint32_t clkrate, uint32_t baudrate);
+
+/**
+ * \brief Register callback to I2C
+ *
+ * This function does low level I2C callback register.
+ *
+ * \param[in] i2c_dev The pointer to i2c device structure
+ * \param[in] cb_type The callback type request
+ * \param[in] func The callback function pointer
+ *
+ * \return Return 0 for success and negative value for error
+ */
+int32_t _i2c_m_async_register_callback(struct _i2c_m_async_device *i2c_dev, enum _i2c_m_async_callback_type cb_type,
+                                       FUNC_PTR func);
+
+/**
+ * \brief Generate stop condition on the I2C bus
+ *
+ * This function will generate a stop condition on the I2C bus
+ *
+ * \param[in] i2c_m_async_descriptor An i2c descriptor which is used to communicate through I2C
+ *
+ * \return Operation status
+ * \retval 0 Operation executed successfully
+ * \retval <0 Operation failed
+ */
+int32_t _i2c_m_async_send_stop(struct _i2c_m_async_device *const i2c_dev);
+
+/**
+ * \brief Returns the number of bytes left or not used in the I2C message buffer
+ *
+ * This function will return the number of bytes left (not written to the bus) or still free
+ * (not received from the bus) in the message buffer, depending on direction of transmission.
+ *
+ * \param[in] i2c_m_async_descriptor An i2c descriptor which is used to communicate through I2C
+ *
+ * \return Number of bytes or error code
+ * \retval >0 Positive number indicating bytes left
+ * \retval 0  Buffer is full/empty depending on direction
+ * \retval <0 Error code
+ */
+int32_t _i2c_m_async_get_bytes_left(struct _i2c_m_async_device *const i2c_dev);
+
+/**
+ * \brief Enable/disable I2C master interrupt
+ *
+ * param[in] device The pointer to I2C master device instance
+ * param[in] type The type of interrupt to disable/enable if applicable
+ * param[in] state Enable or disable
+ */
+void _i2c_m_async_set_irq_state(struct _i2c_m_async_device *const device, const enum _i2c_m_async_callback_type type,
+                                const bool state);
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif
diff --git a/atmel-samd/asf4/samd21/hal/include/hpl_i2c_m_sync.h b/atmel-samd/asf4/samd21/hal/include/hpl_i2c_m_sync.h
new file mode 100644
index 000000000..4a643ee65
--- /dev/null
+++ b/atmel-samd/asf4/samd21/hal/include/hpl_i2c_m_sync.h
@@ -0,0 +1,195 @@
+/**
+ * \file
+ *
+ * \brief I2C Master Hardware Proxy Layer(HPL) declaration.
+ *
+ * Copyright (C) 2014 Atmel Corporation. All rights reserved.
+ *
+ * \asf_license_start
+ *
+ * \page License
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright notice,
+ *    this list of conditions and the following disclaimer.
+ *
+ * 2. Redistributions in binary form must reproduce the above copyright notice,
+ *    this list of conditions and the following disclaimer in the documentation
+ *    and/or other materials provided with the distribution.
+ *
+ * 3. The name of Atmel may not be used to endorse or promote products derived
+ *    from this software without specific prior written permission.
+ *
+ * 4. This software may only be redistributed and used in connection with an
+ *    Atmel microcontroller product.
+ *
+ * THIS SOFTWARE IS PROVIDED BY ATMEL "AS IS" AND ANY EXPRESS OR IMPLIED
+ * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
+ * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT ARE
+ * EXPRESSLY AND SPECIFICALLY DISCLAIMED. IN NO EVENT SHALL ATMEL BE LIABLE FOR
+ * ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+ * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
+ * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
+ * ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+ * POSSIBILITY OF SUCH DAMAGE.
+ *
+ * \asf_license_stop
+ *
+ */
+#ifndef _HPL_I2C_M_SYNC_H_INCLUDED
+#define _HPL_I2C_M_SYNC_H_INCLUDED
+
+#include <compiler.h>
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+/**
+ * \brief i2c flags
+ */
+#define I2C_M_RD 0x0001 /* read data, from slave to master */
+#define I2C_M_BUSY 0x0100
+#define I2C_M_TEN 0x0400   /* this is a ten bit chip address */
+#define I2C_M_SEVEN 0x0800 /* this is a seven bit chip address */
+#define I2C_M_FAIL 0x1000
+#define I2C_M_STOP 0x8000 /* if I2C_FUNC_PROTOCOL_MANGLING */
+
+/**
+ * \brief i2c Return codes
+ */
+#define I2C_OK 0                     /* Operation successful */
+#define I2C_ACK -1                   /* Received ACK from device on I2C bus */
+#define I2C_NACK -2                  /* Received NACK from device on I2C bus */
+#define I2C_ERR_ARBLOST -3           /* Arbitration lost */
+#define I2C_ERR_BAD_ADDRESS -4       /* Bad address */
+#define I2C_ERR_BUS -5               /* Bus error */
+#define I2C_ERR_BUSY -6              /* Device busy */
+#define I2c_ERR_PACKAGE_COLLISION -7 /* Package collision */
+
+/**
+ * \brief i2c I2C Modes
+ */
+#define I2C_STANDARD_MODE 0x00
+#define I2C_FASTMODE 0x01
+#define I2C_HIGHSPEED_MODE 0x02
+
+/**
+ * \brief i2c master message structure
+ */
+struct _i2c_m_msg {
+	uint16_t          addr;
+	volatile uint16_t flags;
+	int32_t           len;
+	uint8_t *         buffer;
+};
+
+/**
+ * \brief i2c master service
+ */
+struct _i2c_m_service {
+	struct _i2c_m_msg msg;
+	uint16_t          mode;
+	uint16_t          trise;
+};
+
+/**
+ * \brief i2c sync master device structure
+ */
+struct _i2c_m_sync_device {
+	struct _i2c_m_service service;
+	void *                hw;
+};
+
+/**
+ * \name HPL functions
+ */
+
+/**
+ * \brief Initialize I2C
+ *
+ * This function does low level I2C configuration.
+ *
+ * \param[in] i2c_dev The pointer to i2c device structure
+ * \param[in] hw The pointer to hardware instance
+ *
+ * \return Return 0 for success and negative value for error
+ */
+int32_t _i2c_m_sync_init(struct _i2c_m_sync_device *const i2c_dev, void *const hw);
+
+/**
+ * \brief Deinitialize I2C
+ *
+ * \param[in] i2c_dev The pointer to i2c device structure
+ *
+ * \return Return 0 for success and negative value for error
+ */
+int32_t _i2c_m_sync_deinit(struct _i2c_m_sync_device *const i2c_dev);
+
+/**
+ * \brief Enable I2C module
+ *
+ * This function does low level I2C enable.
+ *
+ * \param[in] i2c_dev The pointer to i2c device structure
+ *
+ * \return Return 0 for success and negative value for error
+ */
+int32_t _i2c_m_sync_enable(struct _i2c_m_sync_device *const i2c_dev);
+
+/**
+ * \brief Disable I2C module
+ *
+ * This function does low level I2C disable.
+ *
+ * \param[in] i2c_dev The pointer to i2c device structure
+ *
+ * \return Return 0 for success and negative value for error
+ */
+int32_t _i2c_m_sync_disable(struct _i2c_m_sync_device *const i2c_dev);
+
+/**
+ * \brief Transfer data by I2C
+ *
+ * This function does low level I2C data transfer.
+ *
+ * \param[in] i2c_dev The pointer to i2c device structure
+ * \param[in] msg The pointer to i2c msg structure
+ *
+ * \return Return 0 for success and negative value for error
+ */
+int32_t _i2c_m_sync_transfer(struct _i2c_m_sync_device *const i2c_dev, struct _i2c_m_msg *msg);
+
+/**
+ * \brief Set baud rate of I2C
+ *
+ * This function does low level I2C set baud rate.
+ *
+ * \param[in] i2c_dev The pointer to i2c device structure
+ * \param[in] clkrate The clock rate(KHz) input to i2c module
+ * \param[in] baudrate The demand baud rate(KHz) of i2c module
+ *
+ * \return Return 0 for success and negative value for error
+ */
+int32_t _i2c_m_sync_set_baudrate(struct _i2c_m_sync_device *const i2c_dev, uint32_t clkrate, uint32_t baudrate);
+
+/**
+ * \brief Send send condition on the I2C bus
+ *
+ * This function will generate a stop condition on the I2C bus
+ *
+ * \param[in] i2c_dev The pointer to i2c device struct
+ *
+ * \return Return 0 for success and negative value for error
+ */
+int32_t _i2c_m_sync_send_stop(struct _i2c_m_sync_device *const i2c_dev);
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif
diff --git a/atmel-samd/asf4/samd21/hal/include/hpl_i2c_s_async.h b/atmel-samd/asf4/samd21/hal/include/hpl_i2c_s_async.h
new file mode 100644
index 000000000..b240478f7
--- /dev/null
+++ b/atmel-samd/asf4/samd21/hal/include/hpl_i2c_s_async.h
@@ -0,0 +1,194 @@
+/**
+ * \file
+ *
+ * \brief I2C Slave Hardware Proxy Layer(HPL) declaration.
+ *
+ * Copyright (C) 2015 Atmel Corporation. All rights reserved.
+ *
+ * \asf_license_start
+ *
+ * \page License
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright notice,
+ *    this list of conditions and the following disclaimer.
+ *
+ * 2. Redistributions in binary form must reproduce the above copyright notice,
+ *    this list of conditions and the following disclaimer in the documentation
+ *    and/or other materials provided with the distribution.
+ *
+ * 3. The name of Atmel may not be used to endorse or promote products derived
+ *    from this software without specific prior written permission.
+ *
+ * 4. This software may only be redistributed and used in connection with an
+ *    Atmel microcontroller product.
+ *
+ * THIS SOFTWARE IS PROVIDED BY ATMEL "AS IS" AND ANY EXPRESS OR IMPLIED
+ * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
+ * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT ARE
+ * EXPRESSLY AND SPECIFICALLY DISCLAIMED. IN NO EVENT SHALL ATMEL BE LIABLE FOR
+ * ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+ * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
+ * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
+ * ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+ * POSSIBILITY OF SUCH DAMAGE.
+ *
+ * \asf_license_stop
+ *
+ */
+#ifndef _HPL_I2C_S_ASYNC_H_INCLUDED
+#define _HPL_I2C_S_ASYNC_H_INCLUDED
+
+#include "hpl_i2c_s_sync.h"
+#include "hpl_irq.h"
+#include "utils.h"
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+/**
+ * \brief i2c callback types
+ */
+enum _i2c_s_async_callback_type { I2C_S_DEVICE_ERROR, I2C_S_DEVICE_TX, I2C_S_DEVICE_RX_COMPLETE };
+
+/**
+ * \brief Forward declaration of I2C Slave device
+ */
+struct _i2c_s_async_device;
+
+/**
+ * \brief i2c slave callback function type
+ */
+typedef void (*_i2c_s_async_cb_t)(struct _i2c_s_async_device *device);
+
+/**
+ * \brief i2c slave callback pointers structure
+ */
+struct _i2c_s_async_callback {
+	void (*error)(struct _i2c_s_async_device *const device);
+	void (*tx)(struct _i2c_s_async_device *const device);
+	void (*rx_done)(struct _i2c_s_async_device *const device, const uint8_t data);
+};
+
+/**
+ * \brief i2c slave device structure
+ */
+struct _i2c_s_async_device {
+	void *                       hw;
+	struct _i2c_s_async_callback cb;
+	struct _irq_descriptor       irq;
+};
+
+/**
+ * \name HPL functions
+ */
+
+/**
+ * \brief Initialize asynchronous I2C slave
+ *
+ * This function does low level I2C configuration.
+ *
+ * \param[in] device The pointer to i2c interrupt device structure
+ *
+ * \return Return 0 for success and negative value for error
+ */
+int32_t _i2c_s_async_init(struct _i2c_s_async_device *const device, void *const hw);
+
+/**
+ * \brief Deinitialize asynchronous I2C in interrupt mode
+ *
+ * \param[in] device The pointer to i2c device structure
+ *
+ * \return Return 0 for success and negative value for error
+ */
+int32_t _i2c_s_async_deinit(struct _i2c_s_async_device *const device);
+
+/**
+ * \brief Enable I2C module
+ *
+ * This function does low level I2C enable.
+ *
+ * \param[in] device The pointer to i2c slave device structure
+ *
+ * \return Return 0 for success and negative value for error
+ */
+int32_t _i2c_s_async_enable(struct _i2c_s_async_device *const device);
+
+/**
+ * \brief Disable I2C module
+ *
+ * This function does low level I2C disable.
+ *
+ * \param[in] device The pointer to i2c slave device structure
+ *
+ * \return Return 0 for success and negative value for error
+ */
+int32_t _i2c_s_async_disable(struct _i2c_s_async_device *const device);
+
+/**
+ * \brief Check if 10-bit addressing mode is on
+ *
+ * \param[in] device The pointer to i2c slave device structure
+ *
+ * \return Cheking status
+ * \retval 1 10-bit addressing mode is on
+ * \retval 0 10-bit addressing mode is off
+ */
+int32_t _i2c_s_async_is_10bit_addressing_on(const struct _i2c_s_async_device *const device);
+
+/**
+ * \brief Set I2C slave address
+ *
+ * \param[in] device The pointer to i2c slave device structure
+ * \param[in] address Address to set
+ *
+ * \return Return 0 for success and negative value for error
+ */
+int32_t _i2c_s_async_set_address(struct _i2c_s_async_device *const device, const uint16_t address);
+
+/**
+ * \brief Write a byte to the given I2C instance
+ *
+ * \param[in] device The pointer to i2c slave device structure
+ * \param[in] data Data to write
+ */
+void _i2c_s_async_write_byte(struct _i2c_s_async_device *const device, const uint8_t data);
+
+/**
+ * \brief Retrieve I2C slave status
+ *
+ * \param[in] device The pointer to i2c slave device structure
+ *
+ *\return I2C slave status
+ */
+i2c_s_status_t _i2c_s_async_get_status(const struct _i2c_s_async_device *const device);
+
+/**
+ * \brief Abort data transmission
+ *
+ * \param[in] device The pointer to i2c device structure
+ *
+ * \return Return 0 for success and negative value for error
+ */
+int32_t _i2c_s_async_abort_transmission(const struct _i2c_s_async_device *const device);
+
+/**
+ * \brief Enable/disable I2C slave interrupt
+ *
+ * param[in] device The pointer to I2C slave device instance
+ * param[in] type The type of interrupt to disable/enable if applicable
+ * param[in] disable Enable or disable
+ */
+int32_t _i2c_s_async_set_irq_state(struct _i2c_s_async_device *const device, const enum _i2c_s_async_callback_type type,
+                                   const bool disable);
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif /* _HPL_I2C_S_ASYNC_H_INCLUDED */
diff --git a/atmel-samd/asf4/samd21/hal/include/hpl_i2c_s_sync.h b/atmel-samd/asf4/samd21/hal/include/hpl_i2c_s_sync.h
new file mode 100644
index 000000000..a0f4fa465
--- /dev/null
+++ b/atmel-samd/asf4/samd21/hal/include/hpl_i2c_s_sync.h
@@ -0,0 +1,185 @@
+/**
+ * \file
+ *
+ * \brief I2C Slave Hardware Proxy Layer(HPL) declaration.
+ *
+ * Copyright (C) 2015 Atmel Corporation. All rights reserved.
+ *
+ * \asf_license_start
+ *
+ * \page License
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright notice,
+ *    this list of conditions and the following disclaimer.
+ *
+ * 2. Redistributions in binary form must reproduce the above copyright notice,
+ *    this list of conditions and the following disclaimer in the documentation
+ *    and/or other materials provided with the distribution.
+ *
+ * 3. The name of Atmel may not be used to endorse or promote products derived
+ *    from this software without specific prior written permission.
+ *
+ * 4. This software may only be redistributed and used in connection with an
+ *    Atmel microcontroller product.
+ *
+ * THIS SOFTWARE IS PROVIDED BY ATMEL "AS IS" AND ANY EXPRESS OR IMPLIED
+ * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
+ * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT ARE
+ * EXPRESSLY AND SPECIFICALLY DISCLAIMED. IN NO EVENT SHALL ATMEL BE LIABLE FOR
+ * ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+ * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
+ * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
+ * ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+ * POSSIBILITY OF SUCH DAMAGE.
+ *
+ * \asf_license_stop
+ *
+ */
+#ifndef _HPL_I2C_S_SYNC_H_INCLUDED
+#define _HPL_I2C_S_SYNC_H_INCLUDED
+
+#include <compiler.h>
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+/**
+ * \brief I2C Slave status type
+ */
+typedef uint32_t i2c_s_status_t;
+
+/**
+ * \brief i2c slave device structure
+ */
+struct _i2c_s_sync_device {
+	void *hw;
+};
+
+#include <compiler.h>
+
+/**
+ * \name HPL functions
+ */
+
+/**
+ * \brief Initialize synchronous I2C slave
+ *
+ * This function does low level I2C configuration.
+ *
+ * \param[in] device The pointer to i2c slave device structure
+ *
+ * \return Return 0 for success and negative value for error
+ */
+int32_t _i2c_s_sync_init(struct _i2c_s_sync_device *const device, void *const hw);
+
+/**
+ * \brief Deinitialize synchronous I2C slave
+ *
+ * \param[in] device The pointer to i2c slave device structure
+ *
+ * \return Return 0 for success and negative value for error
+ */
+int32_t _i2c_s_sync_deinit(struct _i2c_s_sync_device *const device);
+
+/**
+ * \brief Enable I2C module
+ *
+ * This function does low level I2C enable.
+ *
+ * \param[in] device The pointer to i2c slave device structure
+ *
+ * \return Return 0 for success and negative value for error
+ */
+int32_t _i2c_s_sync_enable(struct _i2c_s_sync_device *const device);
+
+/**
+ * \brief Disable I2C module
+ *
+ * This function does low level I2C disable.
+ *
+ * \param[in] device The pointer to i2c slave device structure
+ *
+ * \return Return 0 for success and negative value for error
+ */
+int32_t _i2c_s_sync_disable(struct _i2c_s_sync_device *const device);
+
+/**
+ * \brief Check if 10-bit addressing mode is on
+ *
+ * \param[in] device The pointer to i2c slave device structure
+ *
+ * \return Cheking status
+ * \retval 1 10-bit addressing mode is on
+ * \retval 0 10-bit addressing mode is off
+ */
+int32_t _i2c_s_sync_is_10bit_addressing_on(const struct _i2c_s_sync_device *const device);
+
+/**
+ * \brief Set I2C slave address
+ *
+ * \param[in] device The pointer to i2c slave device structure
+ * \param[in] address Address to set
+ *
+ * \return Return 0 for success and negative value for error
+ */
+int32_t _i2c_s_sync_set_address(struct _i2c_s_sync_device *const device, const uint16_t address);
+
+/**
+ * \brief Write a byte to the given I2C instance
+ *
+ * \param[in] device The pointer to i2c slave device structure
+ * \param[in] data Data to write
+ */
+void _i2c_s_sync_write_byte(struct _i2c_s_sync_device *const device, const uint8_t data);
+
+/**
+ * \brief Retrieve I2C slave status
+ *
+ * \param[in] device The pointer to i2c slave device structure
+ *
+ *\return I2C slave status
+ */
+i2c_s_status_t _i2c_s_sync_get_status(const struct _i2c_s_sync_device *const device);
+
+/**
+ * \brief Read a byte from the given I2C instance
+ *
+ * \param[in] device The pointer to i2c slave device structure
+ *
+ * \return Data received via I2C interface.
+ */
+uint8_t _i2c_s_sync_read_byte(const struct _i2c_s_sync_device *const device);
+
+/**
+ * \brief Check if I2C is ready to send next byte
+ *
+ * \param[in] device The pointer to i2c slave device structure
+ *
+ * \return Status of the ready check.
+ * \retval true if the I2C is ready to send next byte
+ * \retval false if the I2C is not ready to send next byte
+ */
+bool _i2c_s_sync_is_byte_sent(const struct _i2c_s_sync_device *const device);
+
+/**
+ * \brief Check if there is data received by I2C
+ *
+ * \param[in] device The pointer to i2c slave device structure
+ *
+ * \return Status of the data received check.
+ * \retval true if the I2C has received a byte
+ * \retval false if the I2C has not received a byte
+ */
+bool _i2c_s_sync_is_byte_received(const struct _i2c_s_sync_device *const device);
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif /* _HPL_I2C_S_SYNC_H_INCLUDED */
diff --git a/atmel-samd/asf4/samd21/hal/include/hpl_init.h b/atmel-samd/asf4/samd21/hal/include/hpl_init.h
new file mode 100644
index 000000000..be54600c0
--- /dev/null
+++ b/atmel-samd/asf4/samd21/hal/include/hpl_init.h
@@ -0,0 +1,134 @@
+/**
+ * \file
+ *
+ * \brief Init related functionality declaration.
+ *
+ * Copyright (C) 2014 Atmel Corporation. All rights reserved.
+ *
+ * \asf_license_start
+ *
+ * \page License
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright notice,
+ *    this list of conditions and the following disclaimer.
+ *
+ * 2. Redistributions in binary form must reproduce the above copyright notice,
+ *    this list of conditions and the following disclaimer in the documentation
+ *    and/or other materials provided with the distribution.
+ *
+ * 3. The name of Atmel may not be used to endorse or promote products derived
+ *    from this software without specific prior written permission.
+ *
+ * 4. This software may only be redistributed and used in connection with an
+ *    Atmel microcontroller product.
+ *
+ * THIS SOFTWARE IS PROVIDED BY ATMEL "AS IS" AND ANY EXPRESS OR IMPLIED
+ * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
+ * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT ARE
+ * EXPRESSLY AND SPECIFICALLY DISCLAIMED. IN NO EVENT SHALL ATMEL BE LIABLE FOR
+ * ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+ * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
+ * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
+ * ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+ * POSSIBILITY OF SUCH DAMAGE.
+ *
+ * \asf_license_stop
+ *
+ */
+
+#ifndef _HPL_INIT_H_INCLUDED
+#define _HPL_INIT_H_INCLUDED
+
+/**
+ * \addtogroup HPL Init
+ *
+ * \section hpl_init_rev Revision History
+ * - v1.0.0 Initial Release
+ *
+ *@{
+ */
+
+#include <compiler.h>
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+/**
+ * \name HPL functions
+ */
+//@{
+/**
+ * \brief Initializes clock sources
+ */
+void _sysctrl_init_sources(void);
+
+/**
+ * \brief Initializes Power Manager
+ */
+void _pm_init(void);
+
+/**
+ * \brief Initialize generators
+ */
+void _gclk_init_generators(void);
+
+/**
+ * \brief Initialize 32 kHz clock sources
+ */
+void _osc32kctrl_init_sources(void);
+
+/**
+ * \brief Initialize clock sources
+ */
+void _oscctrl_init_sources(void);
+
+/**
+ * \brief Initialize clock sources that need input reference clocks
+ */
+void _sysctrl_init_referenced_generators(void);
+
+/**
+ * \brief Initialize clock sources that need input reference clocks
+ */
+void _oscctrl_init_referenced_generators(void);
+
+/**
+ * \brief Initialize master clock generator
+ */
+void _mclk_init(void);
+
+/**
+ * \brief Initialize clock generator
+ */
+void _lpmcu_misc_regs_init(void);
+
+/**
+ * \brief Initialize clock generator
+ */
+void _pmc_init(void);
+
+/**
+ * \brief Set performance level
+ *
+ * \param[in] level The performance level to set
+ */
+void _set_performance_level(const uint8_t level);
+
+/**
+ * \brief Initialize the chip
+ */
+void _init_chip(void);
+
+//@}
+
+#ifdef __cplusplus
+}
+#endif
+/**@}*/
+#endif /* _HPL_INIT_H_INCLUDED */
diff --git a/atmel-samd/asf4/samd21/hal/include/hpl_irq.h b/atmel-samd/asf4/samd21/hal/include/hpl_irq.h
new file mode 100644
index 000000000..7325b5711
--- /dev/null
+++ b/atmel-samd/asf4/samd21/hal/include/hpl_irq.h
@@ -0,0 +1,126 @@
+/**
+ * \file
+ *
+ * \brief IRQ related functionality declaration.
+ *
+ * Copyright (C) 2014 Atmel Corporation. All rights reserved.
+ *
+ * \asf_license_start
+ *
+ * \page License
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright notice,
+ *    this list of conditions and the following disclaimer.
+ *
+ * 2. Redistributions in binary form must reproduce the above copyright notice,
+ *    this list of conditions and the following disclaimer in the documentation
+ *    and/or other materials provided with the distribution.
+ *
+ * 3. The name of Atmel may not be used to endorse or promote products derived
+ *    from this software without specific prior written permission.
+ *
+ * 4. This software may only be redistributed and used in connection with an
+ *    Atmel microcontroller product.
+ *
+ * THIS SOFTWARE IS PROVIDED BY ATMEL "AS IS" AND ANY EXPRESS OR IMPLIED
+ * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
+ * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT ARE
+ * EXPRESSLY AND SPECIFICALLY DISCLAIMED. IN NO EVENT SHALL ATMEL BE LIABLE FOR
+ * ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+ * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
+ * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
+ * ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+ * POSSIBILITY OF SUCH DAMAGE.
+ *
+ * \asf_license_stop
+ *
+ */
+
+#ifndef _HPL_IRQ_H_INCLUDED
+#define _HPL_IRQ_H_INCLUDED
+
+/**
+ * \addtogroup HPL IRQ
+ *
+ * \section hpl_irq_rev Revision History
+ * - v1.0.0 Initial Release
+ *
+ *@{
+ */
+
+#include <compiler.h>
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+/**
+ * \brief IRQ descriptor
+ */
+struct _irq_descriptor {
+	void (*handler)(void *parameter);
+	void *parameter;
+};
+
+/**
+ * \name HPL functions
+ */
+//@{
+/**
+ * \brief Retrieve current IRQ number
+ *
+ * \return The current IRQ number
+ */
+uint8_t _irq_get_current(void);
+
+/**
+ * \brief Disable the given IRQ
+ *
+ * \param[in] n The number of IRQ to disable
+ */
+void _irq_disable(uint8_t n);
+
+/**
+ * \brief Set the given IRQ
+ *
+ * \param[in] n The number of IRQ to set
+ */
+void _irq_set(uint8_t n);
+
+/**
+ * \brief Clear the given IRQ
+ *
+ * \param[in] n The number of IRQ to clear
+ */
+void _irq_clear(uint8_t n);
+
+/**
+ * \brief Enable the given IRQ
+ *
+ * \param[in] n The number of IRQ to enable
+ */
+void _irq_enable(uint8_t n);
+
+/**
+ * \brief Register IRQ handler
+ *
+ * \param[in] number The number registered IRQ
+ * \param[in] irq The pointer to irq handler to register
+ *
+ * \return The status of IRQ handler registering
+ * \retval -1 Passed parameters were invalid
+ * \retval 0 The registering is completed successfully
+ */
+void _irq_register(const uint8_t number, struct _irq_descriptor *const irq);
+//@}
+
+#ifdef __cplusplus
+}
+#endif
+/**@}*/
+#endif /* _HPL_IRQ_H_INCLUDED */
diff --git a/atmel-samd/asf4/samd21/hal/include/hpl_missing_features.h b/atmel-samd/asf4/samd21/hal/include/hpl_missing_features.h
new file mode 100644
index 000000000..90fa16be4
--- /dev/null
+++ b/atmel-samd/asf4/samd21/hal/include/hpl_missing_features.h
@@ -0,0 +1,47 @@
+/**
+ * \file
+ *
+ * \brief Family-dependent missing features expected by HAL
+ *
+ * Copyright (C) 2016 Atmel Corporation. All rights reserved.
+ *
+ * \asf_license_start
+ *
+ * \page License
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright notice,
+ *    this list of conditions and the following disclaimer.
+ *
+ * 2. Redistributions in binary form must reproduce the above copyright notice,
+ *    this list of conditions and the following disclaimer in the documentation
+ *    and/or other materials provided with the distribution.
+ *
+ * 3. The name of Atmel may not be used to endorse or promote products derived
+ *    from this software without specific prior written permission.
+ *
+ * 4. This software may only be redistributed and used in connection with an
+ *    Atmel microcontroller product.
+ *
+ * THIS SOFTWARE IS PROVIDED BY ATMEL "AS IS" AND ANY EXPRESS OR IMPLIED
+ * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
+ * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT ARE
+ * EXPRESSLY AND SPECIFICALLY DISCLAIMED. IN NO EVENT SHALL ATMEL BE LIABLE FOR
+ * ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+ * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
+ * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
+ * ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+ * POSSIBILITY OF SUCH DAMAGE.
+ *
+ * \asf_license_stop
+ *
+ */
+
+#ifndef _HPL_MISSING_FEATURES
+#define _HPL_MISSING_FEATURES
+
+#endif /* _HPL_MISSING_FEATURES */
diff --git a/atmel-samd/asf4/samd21/hal/include/hpl_pwm.h b/atmel-samd/asf4/samd21/hal/include/hpl_pwm.h
new file mode 100644
index 000000000..8deb54cc0
--- /dev/null
+++ b/atmel-samd/asf4/samd21/hal/include/hpl_pwm.h
@@ -0,0 +1,203 @@
+/**
+ * \file
+ *
+ * \brief PWM related functionality declaration.
+ *
+ * Copyright (C) 2014-2016 Atmel Corporation. All rights reserved.
+ *
+ * \asf_license_start
+ *
+ * \page License
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright notice,
+ *    this list of conditions and the following disclaimer.
+ *
+ * 2. Redistributions in binary form must reproduce the above copyright notice,
+ *    this list of conditions and the following disclaimer in the documentation
+ *    and/or other materials provided with the distribution.
+ *
+ * 3. The name of Atmel may not be used to endorse or promote products derived
+ *    from this software without specific prior written permission.
+ *
+ * 4. This software may only be redistributed and used in connection with an
+ *    Atmel microcontroller product.
+ *
+ * THIS SOFTWARE IS PROVIDED BY ATMEL "AS IS" AND ANY EXPRESS OR IMPLIED
+ * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
+ * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT ARE
+ * EXPRESSLY AND SPECIFICALLY DISCLAIMED. IN NO EVENT SHALL ATMEL BE LIABLE FOR
+ * ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+ * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
+ * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
+ * ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+ * POSSIBILITY OF SUCH DAMAGE.
+ *
+ * \asf_license_stop
+ *
+ */
+#ifndef _HPL_PWM_H_INCLUDED
+#define _HPL_PWM_H_INCLUDED
+
+/**
+ * \addtogroup HPL PWM
+ *
+ * \section hpl_pwm_rev Revision History
+ * - v1.0.0 Initial Release
+ *
+ *@{
+ */
+
+#include <compiler.h>
+#include "hpl_irq.h"
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+/**
+ * \brief PWM callback types
+ */
+enum _pwm_callback_type { PWM_DEVICE_PERIOD_CB, PWM_DEVICE_ERROR_CB };
+
+/**
+ * \brief PWM pulse-width period
+ */
+typedef uint32_t pwm_period_t;
+
+/**
+ * \brief PWM device structure
+ *
+ * The PWM device structure forward declaration.
+ */
+struct _pwm_device;
+
+/**
+ * \brief PWM interrupt callbacks
+ */
+struct _pwm_callback {
+	void (*pwm_period_cb)(struct _pwm_device *device);
+	void (*pwm_error_cb)(struct _pwm_device *device);
+};
+
+/**
+ * \brief PWM descriptor device structure
+ */
+struct _pwm_device {
+	struct _pwm_callback   callback;
+	struct _irq_descriptor irq;
+	void *                 hw;
+};
+
+/**
+ * \brief PWM functions, pointers to low-level functions
+ */
+struct _pwm_hpl_interface {
+	int32_t (*init)(struct _pwm_device *const device, void *const hw);
+	void (*deinit)(struct _pwm_device *const device);
+	void (*start_pwm)(struct _pwm_device *const device);
+	void (*stop_pwm)(struct _pwm_device *const device);
+	void (*set_pwm_param)(struct _pwm_device *const device, const pwm_period_t period, const pwm_period_t duty_cycle);
+	bool (*is_pwm_enabled)(const struct _pwm_device *const device);
+	pwm_period_t (*pwm_get_period)(const struct _pwm_device *const device);
+	uint32_t (*pwm_get_duty)(const struct _pwm_device *const device);
+	void (*set_irq_state)(struct _pwm_device *const device, const enum _pwm_callback_type type, const bool disable);
+};
+/**
+ * \brief Initialize TC
+ *
+ * This function does low level TC configuration.
+ *
+ * \param[in] device The pointer to PWM device instance
+ * \param[in] hw The pointer to hardware instance
+ *
+ * \return Initialization status.
+ */
+int32_t _pwm_init(struct _pwm_device *const device, void *const hw);
+
+/**
+ * \brief Deinitialize TC
+ *
+ * \param[in] device The pointer to PWM device instance
+ */
+void _pwm_deinit(struct _pwm_device *const device);
+
+/**
+ * \brief Retrieve offset of the given tc hardware instance
+ *
+ * \param[in] device The pointer to PWM device instance
+ *
+ * \return The offset of the given tc hardware instance
+ */
+uint8_t _pwm_get_hardware_offset(const struct _pwm_device *const device);
+
+/**
+ * \brief Start hardware pwm
+ *
+ * \param[in] device The pointer to PWM device instance
+ */
+void _pwm_enable(struct _pwm_device *const device);
+
+/**
+ * \brief Stop hardware pwm
+ *
+ * \param[in] device The pointer to PWM device instance
+ */
+void _pwm_disable(struct _pwm_device *const device);
+
+/**
+ * \brief Set pwm parameter
+ *
+ * \param[in] device The pointer to PWM device instance
+ * \param[in] period Total period of one PWM cycle.
+ * \param[in] duty_cycle Period of PWM first half during one cycle.
+ */
+void _pwm_set_param(struct _pwm_device *const device, const pwm_period_t period, const pwm_period_t duty_cycle);
+
+/**
+ * \brief Check if pwm is working
+ *
+ * \param[in] device The pointer to PWM device instance
+ *
+ * \return Check status.
+ * \retval true The given pwm is working
+ * \retval false The given pwm is not working
+ */
+bool _pwm_is_enabled(const struct _pwm_device *const device);
+
+/**
+ * \brief Get pwm waveform period value
+ *
+ * \param[in] device The pointer to PWM device instance
+ *
+ * \return Period value.
+ */
+pwm_period_t _pwm_get_period(const struct _pwm_device *const device);
+
+/**
+ * \brief Get pwm waveform duty cycle value
+ *
+ * \param[in] device The pointer to PWM device instance
+ *
+ * \return Duty cycle value
+ */
+uint32_t _pwm_get_duty(const struct _pwm_device *const device);
+
+/**
+ * \brief Enable/disable PWM interrupt
+ *
+ * param[in] device The pointer to PWM device instance
+ * param[in] type The type of interrupt to disable/enable if applicable
+ * param[in] disable Enable or disable
+ */
+void _pwm_set_irq_state(struct _pwm_device *const device, const enum _pwm_callback_type type, const bool disable);
+
+#ifdef __cplusplus
+}
+#endif
+/**@}*/
+#endif /* _HPL_PWM_H_INCLUDED */
diff --git a/atmel-samd/asf4/samd21/hal/include/hpl_reset.h b/atmel-samd/asf4/samd21/hal/include/hpl_reset.h
new file mode 100644
index 000000000..868591ee6
--- /dev/null
+++ b/atmel-samd/asf4/samd21/hal/include/hpl_reset.h
@@ -0,0 +1,102 @@
+/**
+ * \file
+ *
+ * \brief Reset related functionality declaration.
+ *
+ * Copyright (C) 2014 Atmel Corporation. All rights reserved.
+ *
+ * \asf_license_start
+ *
+ * \page License
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright notice,
+ *    this list of conditions and the following disclaimer.
+ *
+ * 2. Redistributions in binary form must reproduce the above copyright notice,
+ *    this list of conditions and the following disclaimer in the documentation
+ *    and/or other materials provided with the distribution.
+ *
+ * 3. The name of Atmel may not be used to endorse or promote products derived
+ *    from this software without specific prior written permission.
+ *
+ * 4. This software may only be redistributed and used in connection with an
+ *    Atmel microcontroller product.
+ *
+ * THIS SOFTWARE IS PROVIDED BY ATMEL "AS IS" AND ANY EXPRESS OR IMPLIED
+ * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
+ * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT ARE
+ * EXPRESSLY AND SPECIFICALLY DISCLAIMED. IN NO EVENT SHALL ATMEL BE LIABLE FOR
+ * ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+ * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
+ * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
+ * ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+ * POSSIBILITY OF SUCH DAMAGE.
+ *
+ * \asf_license_stop
+ *
+ */
+
+#ifndef _HPL_RESET_H_INCLUDED
+#define _HPL_RESET_H_INCLUDED
+
+/**
+ * \addtogroup HPL Reset
+ *
+ * \section hpl_reset_rev Revision History
+ * - v1.0.0 Initial Release
+ *
+ *@{
+ */
+
+#ifndef _UNIT_TEST_
+#include <compiler.h>
+#endif
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+/**
+ * \brief Reset reason enumeration
+ *
+ * The list of possible reset reasons.
+ */
+enum reset_reason {
+	RESET_REASON_POR    = 1,
+	RESET_REASON_BOD12  = 2,
+	RESET_REASON_BOD33  = 4,
+	RESET_REASON_EXT    = 8,
+	RESET_REASON_WDT    = 16,
+	RESET_REASON_SYST   = 32,
+	RESET_REASON_BACKUP = 64
+};
+
+/**
+ * \name HPL functions
+ */
+//@{
+/**
+ * \brief Retrieve the reset reason
+ *
+ * Retrieves the reset reason of the last MCU reset.
+ *
+ *\return An enum value indicating the reason of the last reset.
+ */
+enum reset_reason _get_reset_reason(void);
+
+/**
+ * \brief Reset MCU
+ */
+void _reset_mcu(void);
+//@}
+
+#ifdef __cplusplus
+}
+#endif
+/**@}*/
+#endif /* _HPL_RESET_H_INCLUDED */
diff --git a/atmel-samd/asf4/samd21/hal/include/hpl_sleep.h b/atmel-samd/asf4/samd21/hal/include/hpl_sleep.h
new file mode 100644
index 000000000..3bd6a1cb2
--- /dev/null
+++ b/atmel-samd/asf4/samd21/hal/include/hpl_sleep.h
@@ -0,0 +1,98 @@
+/**
+ * \file
+ *
+ * \brief Sleep related functionality declaration.
+ *
+ * Copyright (C) 2014 Atmel Corporation. All rights reserved.
+ *
+ * \asf_license_start
+ *
+ * \page License
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright notice,
+ *    this list of conditions and the following disclaimer.
+ *
+ * 2. Redistributions in binary form must reproduce the above copyright notice,
+ *    this list of conditions and the following disclaimer in the documentation
+ *    and/or other materials provided with the distribution.
+ *
+ * 3. The name of Atmel may not be used to endorse or promote products derived
+ *    from this software without specific prior written permission.
+ *
+ * 4. This software may only be redistributed and used in connection with an
+ *    Atmel microcontroller product.
+ *
+ * THIS SOFTWARE IS PROVIDED BY ATMEL "AS IS" AND ANY EXPRESS OR IMPLIED
+ * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
+ * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT ARE
+ * EXPRESSLY AND SPECIFICALLY DISCLAIMED. IN NO EVENT SHALL ATMEL BE LIABLE FOR
+ * ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+ * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
+ * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
+ * ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+ * POSSIBILITY OF SUCH DAMAGE.
+ *
+ * \asf_license_stop
+ *
+ */
+
+#ifndef _HPL_SLEEP_H_INCLUDED
+#define _HPL_SLEEP_H_INCLUDED
+
+/**
+ * \addtogroup HPL Sleep
+ *
+ * \section hpl_sleep_rev Revision History
+ * - v1.0.0 Initial Release
+ *
+ *@{
+ */
+
+#ifndef _UNIT_TEST_
+#include <compiler.h>
+#endif
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+/**
+ * \name HPL functions
+ */
+//@{
+/**
+ * \brief Set the sleep mode for the device
+ *
+ * This function sets the sleep mode for the device.
+ * For an overview of which systems are disabled in sleep for the different
+ * sleep modes see datasheet.
+ *
+ * \param[in] mode Sleep mode to use
+ *
+ * \return the status of a sleep request
+ * \retval -1 The requested sleep mode was invalid
+ * \retval  0 The operation completed successfully, sleep mode is set
+ */
+int32_t _set_sleep_mode(const uint8_t mode);
+
+/**
+ * \brief Reset MCU
+ */
+void _reset_mcu(void);
+
+/**
+ * \brief Put MCU to sleep
+ */
+void _go_to_sleep(void);
+//@}
+
+#ifdef __cplusplus
+}
+#endif
+/**@}*/
+#endif /* _HPL_SLEEP_H_INCLUDED */
diff --git a/atmel-samd/asf4/samd21/hal/include/hpl_spi.h b/atmel-samd/asf4/samd21/hal/include/hpl_spi.h
new file mode 100644
index 000000000..14177642f
--- /dev/null
+++ b/atmel-samd/asf4/samd21/hal/include/hpl_spi.h
@@ -0,0 +1,173 @@
+/**
+ * \file
+ *
+ * \brief SPI related functionality declaration.
+ *
+ * Copyright (C) 2014 - 2015 Atmel Corporation. All rights reserved.
+ *
+ * \asf_license_start
+ *
+ * \page License
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright notice,
+ *    this list of conditions and the following disclaimer.
+ *
+ * 2. Redistributions in binary form must reproduce the above copyright notice,
+ *    this list of conditions and the following disclaimer in the documentation
+ *    and/or other materials provided with the distribution.
+ *
+ * 3. The name of Atmel may not be used to endorse or promote products derived
+ *    from this software without specific prior written permission.
+ *
+ * 4. This software may only be redistributed and used in connection with an
+ *    Atmel microcontroller product.
+ *
+ * THIS SOFTWARE IS PROVIDED BY ATMEL "AS IS" AND ANY EXPRESS OR IMPLIED
+ * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
+ * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT ARE
+ * EXPRESSLY AND SPECIFICALLY DISCLAIMED. IN NO EVENT SHALL ATMEL BE LIABLE FOR
+ * ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+ * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
+ * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
+ * ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+ * POSSIBILITY OF SUCH DAMAGE.
+ *
+ * \asf_license_stop
+ *
+ */
+
+#ifndef _HPL_SPI_H_INCLUDED
+#define _HPL_SPI_H_INCLUDED
+
+#include <compiler.h>
+#include <utils.h>
+
+/**
+ * \addtogroup hpl_spi HPL SPI
+ *
+ *@{
+ */
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+/**
+ * \brief SPI Dummy char is used when reading data from the SPI slave
+ */
+#define SPI_DUMMY_CHAR 0x1ff
+
+/**
+ *  \brief SPI message to let driver to process
+ */
+//@{
+struct spi_msg {
+	/** Pointer to the output data buffer */
+	uint8_t *txbuf;
+	/** Pointer to the input data buffer */
+	uint8_t *rxbuf;
+	/** Size of the message data in SPI characters */
+	uint32_t size;
+};
+//@}
+
+/**
+ *  \brief SPI transfer modes
+ *  SPI transfer mode controls clock polarity and clock phase.
+ *  Mode 0: leading edge is rising edge, data sample on leading edge.
+ *  Mode 1: leading edge is rising edge, data sample on trailing edge.
+ *  Mode 2: leading edge is falling edge, data sample on leading edge.
+ *  Mode 3: leading edge is falling edge, data sample on trailing edge.
+ */
+enum spi_transfer_mode {
+	/** Leading edge is rising edge, data sample on leading edge. */
+	SPI_MODE_0,
+	/** Leading edge is rising edge, data sample on trailing edge. */
+	SPI_MODE_1,
+	/** Leading edge is falling edge, data sample on leading edge. */
+	SPI_MODE_2,
+	/** Leading edge is falling edge, data sample on trailing edge. */
+	SPI_MODE_3
+};
+
+/**
+ *  \brief SPI character sizes
+ *  The character size influence the way the data is sent/received.
+ *  For char size <= 8 data is stored byte by byte.
+ *  For char size between 9 ~ 16 data is stored in 2-byte length.
+ *  Note that the default and recommended char size is 8 bit since it's
+ *  supported by all system.
+ */
+enum spi_char_size {
+	/** Character size is 8 bit. */
+	SPI_CHAR_SIZE_8 = 0,
+	/** Character size is 9 bit. */
+	SPI_CHAR_SIZE_9 = 1,
+	/** Character size is 10 bit. */
+	SPI_CHAR_SIZE_10 = 2,
+	/** Character size is 11 bit. */
+	SPI_CHAR_SIZE_11 = 3,
+	/** Character size is 12 bit. */
+	SPI_CHAR_SIZE_12 = 4,
+	/** Character size is 13 bit. */
+	SPI_CHAR_SIZE_13 = 5,
+	/** Character size is 14 bit. */
+	SPI_CHAR_SIZE_14 = 6,
+	/** Character size is 15 bit. */
+	SPI_CHAR_SIZE_15 = 7,
+	/** Character size is 16 bit. */
+	SPI_CHAR_SIZE_16 = 8
+};
+
+/**
+ *  \brief SPI data order
+ */
+enum spi_data_order {
+	/** MSB goes first. */
+	SPI_DATA_ORDER_MSB_1ST = 0,
+	/** LSB goes first. */
+	SPI_DATA_ORDER_LSB_1ST = 1
+};
+
+/** \brief Transfer descriptor for SPI
+ *  Transfer descriptor holds TX and RX buffers
+ */
+struct spi_xfer {
+	/** Pointer to data buffer to TX */
+	uint8_t *txbuf;
+	/** Pointer to data buffer to RX */
+	uint8_t *rxbuf;
+	/** Size of data characters to TX & RX */
+	uint32_t size;
+};
+
+/** SPI generic driver. */
+struct spi_dev {
+	/** Pointer to the hardware base or private data for special device. */
+	void *prvt;
+	/** Reference start of sync/async variables */
+	uint32_t sync_async_misc[1];
+};
+
+/**
+ *  \brief Calculate the baudrate value for hardware to use to set baudrate
+ *  \param[in, out] dev Pointer to the SPI device instance.
+ *  \param[in] clk Clock frequency (Hz) for baudrate generation.
+ *  \param[in] baud Target baudrate (bps).
+ *  \return Error or baudrate value.
+ *  \retval >0 Baudrate value.
+ *  \retval ERR_INVALID_ARG Calculation fail.
+ */
+int32_t _spi_calc_baud_val(struct spi_dev *dev, const uint32_t clk, const uint32_t baud);
+
+#ifdef __cplusplus
+}
+#endif
+
+/**@}*/
+#endif /* ifndef _HPL_SPI_H_INCLUDED */
diff --git a/atmel-samd/asf4/samd21/hal/include/hpl_spi_async.h b/atmel-samd/asf4/samd21/hal/include/hpl_spi_async.h
new file mode 100644
index 000000000..b81ef12af
--- /dev/null
+++ b/atmel-samd/asf4/samd21/hal/include/hpl_spi_async.h
@@ -0,0 +1,137 @@
+/**
+ * \file
+ *
+ * \brief Common SPI related functionality declaration.
+ *
+ * Copyright (C) 2015 Atmel Corporation. All rights reserved.
+ *
+ * \asf_license_start
+ *
+ * \page License
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright notice,
+ *    this list of conditions and the following disclaimer.
+ *
+ * 2. Redistributions in binary form must reproduce the above copyright notice,
+ *    this list of conditions and the following disclaimer in the documentation
+ *    and/or other materials provided with the distribution.
+ *
+ * 3. The name of Atmel may not be used to endorse or promote products derived
+ *    from this software without specific prior written permission.
+ *
+ * 4. This software may only be redistributed and used in connection with an
+ *    Atmel microcontroller product.
+ *
+ * THIS SOFTWARE IS PROVIDED BY ATMEL "AS IS" AND ANY EXPRESS OR IMPLIED
+ * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
+ * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT ARE
+ * EXPRESSLY AND SPECIFICALLY DISCLAIMED. IN NO EVENT SHALL ATMEL BE LIABLE FOR
+ * ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+ * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
+ * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
+ * ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+ * POSSIBILITY OF SUCH DAMAGE.
+ *
+ * \asf_license_stop
+ *
+ */
+
+#ifndef _HPL_SPI_ASYNC_H_INCLUDED
+#define _HPL_SPI_ASYNC_H_INCLUDED
+
+#include <hpl_spi.h>
+#include <hpl_irq.h>
+
+/**
+ * \addtogroup hpl_spi HPL SPI
+ *
+ *@{
+ */
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+/**
+ *  \brief Callbacks the SPI driver must offer in async mode
+ */
+//@{
+/** The callback types */
+enum _spi_async_dev_cb_type {
+	/** Callback type for transmit, see \ref _spi_async_dev_cb_xfer_t. */
+	SPI_DEV_CB_TX,
+	/** Callback type for receive, see \ref _spi_async_dev_cb_xfer_t. */
+	SPI_DEV_CB_RX,
+	/** Callback type for \ref _spi_async_dev_cb_complete_t. */
+	SPI_DEV_CB_COMPLETE,
+	/** Number of callbacks. */
+	SPI_DEV_CB_N
+};
+
+struct _spi_async_dev;
+
+/** \brief The prototype for callback on SPI transfer complete.
+ *  If status code is zero, it indicates the normal completion, that is,
+ *  SS deactivation.
+ *  If status code belows zero, it indicates complete.
+ */
+typedef void (*_spi_async_dev_cb_complete_t)(struct _spi_async_dev *dev, int32_t status);
+
+/** \brief The prototype for callback on SPI transmit/receive event
+ *  For TX, the callback is invoked when transmit is done or ready to start
+ *  transmit.
+ *  For RX, the callback is invoked when receive is done or ready to read data,
+ *  see \ref _spi_async_dev_read_one_t on data reading.
+ *  Without DMA enabled, the callback is invoked on each character event.
+ *  With DMA enabled, the callback is invoked on DMA buffer done.
+ */
+typedef void (*_spi_async_dev_cb_xfer_t)(struct _spi_async_dev *dev);
+
+/**
+ *  \brief The callbacks offered by SPI driver
+ */
+struct _spi_async_dev_callbacks {
+	/** TX callback, see \ref _spi_async_dev_cb_xfer_t. */
+	_spi_async_dev_cb_xfer_t tx;
+	/** RX callback, see \ref _spi_async_dev_cb_xfer_t. */
+	_spi_async_dev_cb_xfer_t rx;
+	/** Complete or complete callback, see \ref _spi_async_dev_cb_complete_t. */
+	_spi_async_dev_cb_complete_t complete;
+};
+//@}
+
+/**
+ *  \brief SPI async driver
+ */
+//@{
+
+/** SPI driver to support async HAL */
+struct _spi_async_dev {
+	/** Pointer to the hardware base or private data for special device. */
+	void *prvt;
+	/** Data size, number of bytes for each character */
+	uint8_t char_size;
+	/** Dummy byte used in master mode when reading the slave */
+	uint16_t dummy_byte;
+
+	/** \brief Pointer to callback functions, ignored for polling mode
+	 *  Pointer to the callback functions so that initialize the driver to
+	 *  handle interrupts.
+	 */
+	struct _spi_async_dev_callbacks callbacks;
+	/** IRQ instance for SPI device. */
+	struct _irq_descriptor irq;
+};
+//@}
+
+#ifdef __cplusplus
+}
+#endif
+
+/**@}*/
+#endif /* ifndef _HPL_SPI_ASYNC_H_INCLUDED */
diff --git a/atmel-samd/asf4/samd21/hal/include/hpl_spi_dma.h b/atmel-samd/asf4/samd21/hal/include/hpl_spi_dma.h
new file mode 100644
index 000000000..3f2088c05
--- /dev/null
+++ b/atmel-samd/asf4/samd21/hal/include/hpl_spi_dma.h
@@ -0,0 +1,98 @@
+/**
+ * \file
+ *
+ * \brief Common SPI DMA related functionality declaration.
+ *
+ * Copyright (C) 2016 Atmel Corporation. All rights reserved.
+ *
+ * \asf_license_start
+ *
+ * \page License
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright notice,
+ *    this list of conditions and the following disclaimer.
+ *
+ * 2. Redistributions in binary form must reproduce the above copyright notice,
+ *    this list of conditions and the following disclaimer in the documentation
+ *    and/or other materials provided with the distribution.
+ *
+ * 3. The name of Atmel may not be used to endorse or promote products derived
+ *    from this software without specific prior written permission.
+ *
+ * 4. This software may only be redistributed and used in connection with an
+ *    Atmel microcontroller product.
+ *
+ * THIS SOFTWARE IS PROVIDED BY ATMEL "AS IS" AND ANY EXPRESS OR IMPLIED
+ * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
+ * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT ARE
+ * EXPRESSLY AND SPECIFICALLY DISCLAIMED. IN NO EVENT SHALL ATMEL BE LIABLE FOR
+ * ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+ * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
+ * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
+ * ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+ * POSSIBILITY OF SUCH DAMAGE.
+ *
+ * \asf_license_stop
+ *
+ */
+
+#ifndef _HPL_SPI_DMA_H_INCLUDED
+#define _HPL_SPI_DMA_H_INCLUDED
+
+#include <hpl_irq.h>
+#include <hpl_dma.h>
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+/** The callback types */
+enum _spi_dma_dev_cb_type {
+	/** Callback type for DMA transmit. */
+	SPI_DEV_CB_DMA_TX,
+	/** Callback type for DMA receive. */
+	SPI_DEV_CB_DMA_RX,
+	/** Callback type for DMA error. */
+	SPI_DEV_CB_DMA_ERROR,
+	/** Number of callbacks. */
+	SPI_DEV_CB_DMA_N
+};
+
+struct _spi_dma_dev;
+
+/**
+ *  \brief The prototype for callback on SPI DMA.
+ */
+typedef void (*_spi_dma_cb_t)(struct _dma_resource *resource);
+
+/**
+ *  \brief The callbacks offered by SPI driver
+ */
+struct _spi_dma_dev_callbacks {
+	_spi_dma_cb_t tx;
+	_spi_dma_cb_t rx;
+	_spi_dma_cb_t error;
+};
+
+/** SPI driver to support DMA HAL */
+struct _spi_dma_dev {
+	/** Pointer to the hardware base or private data for special device. */
+	void *prvt;
+	/** Pointer to callback functions */
+	struct _spi_dma_dev_callbacks callbacks;
+	/** IRQ instance for SPI device. */
+	struct _irq_descriptor irq;
+	/** DMA resource */
+	struct _dma_resource *resource;
+};
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif /* ifndef _HPL_SPI_DMA_H_INCLUDED */
diff --git a/atmel-samd/asf4/samd21/hal/include/hpl_spi_m_async.h b/atmel-samd/asf4/samd21/hal/include/hpl_spi_m_async.h
new file mode 100644
index 000000000..f2d330495
--- /dev/null
+++ b/atmel-samd/asf4/samd21/hal/include/hpl_spi_m_async.h
@@ -0,0 +1,248 @@
+/**
+ * \file
+ *
+ * \brief SPI Slave Async related functionality declaration.
+ *
+ * Copyright (C) 2015 Atmel Corporation. All rights reserved.
+ *
+ * \asf_license_start
+ *
+ * \page License
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright notice,
+ *    this list of conditions and the following disclaimer.
+ *
+ * 2. Redistributions in binary form must reproduce the above copyright notice,
+ *    this list of conditions and the following disclaimer in the documentation
+ *    and/or other materials provided with the distribution.
+ *
+ * 3. The name of Atmel may not be used to endorse or promote products derived
+ *    from this software without specific prior written permission.
+ *
+ * 4. This software may only be redistributed and used in connection with an
+ *    Atmel microcontroller product.
+ *
+ * THIS SOFTWARE IS PROVIDED BY ATMEL "AS IS" AND ANY EXPRESS OR IMPLIED
+ * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
+ * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT ARE
+ * EXPRESSLY AND SPECIFICALLY DISCLAIMED. IN NO EVENT SHALL ATMEL BE LIABLE FOR
+ * ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+ * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
+ * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
+ * ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+ * POSSIBILITY OF SUCH DAMAGE.
+ *
+ * \asf_license_stop
+ *
+ */
+
+#ifndef _HPL_SPI_M_ASYNC_H_INCLUDED
+#define _HPL_SPI_M_ASYNC_H_INCLUDED
+
+#include <hpl_spi.h>
+#include <hpl_spi_async.h>
+
+/**
+ * \addtogroup hpl_spi HPL SPI
+ *
+ *
+ *@{
+ */
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+/** Uses common SPI async device driver. */
+#define _spi_m_async_dev _spi_async_dev
+
+#define _spi_m_async_dev_cb_type _spi_async_dev_cb_type
+
+/** Uses common SPI async device driver complete callback type. */
+#define _spi_m_async_dev_cb_complete_t _spi_async_dev_cb_complete_t
+
+/** Uses common SPI async device driver transfer callback type. */
+#define _spi_m_async_dev_cb_xfer_t _spi_async_dev_cb_xfer_t
+
+/**
+ *  \brief Initialize SPI for access with interrupts
+ *  It will load default hardware configuration and software struct.
+ *  \param[in, out] dev Pointer to the SPI device instance.
+ *  \param[in] hw Pointer to the hardware base.
+ *  \retval ERR_INVALID_ARG Input parameter problem.
+ *  \retval ERR_BUSY SPI hardware not ready (resetting).
+ *  \retval ERR_DENIED SPI has been enabled.
+ *  \retval 0 Operation done successfully.
+ */
+int32_t _spi_m_async_init(struct _spi_m_async_dev *dev, void *const hw);
+
+/**
+ *  \brief Initialize SPI for access with interrupts
+ *  Disable, reset the hardware and the software struct.
+ *  \param[in, out] dev Pointer to the SPI device instance.
+ *  \return Operation status.
+ *  \retval 0 Operation done successfully.
+ */
+int32_t _spi_m_async_deinit(struct _spi_m_async_dev *dev);
+
+/**
+ *  \brief Enable SPI for access with interrupts
+ *  Enable the SPI and enable callback generation of receive and error
+ *  interrupts.
+ *  \param[in, out] dev Pointer to the SPI device instance.
+ *  \return Operation status.
+ *  \retval ERR_INVALID_ARG Input parameter problem.
+ *  \retval ERR_BUSY SPI hardware not ready (resetting).
+ *  \retval 0 Operation done successfully.
+ */
+int32_t _spi_m_async_enable(struct _spi_m_async_dev *dev);
+
+/**
+ *  \brief Disable SPI for access without interrupts
+ *  Disable SPI and interrupts. Deactivate all CS pins if works as master.
+ *  \param[in, out] dev Pointer to the SPI device instance.
+ *  \return Operation status.
+ *  \retval 0 Operation done successfully.
+ */
+int32_t _spi_m_async_disable(struct _spi_m_async_dev *dev);
+
+/**
+ *  \brief Set SPI transfer mode
+ *  Set SPI transfer mode (\ref spi_transfer_mode),
+ *  which controls clock polarity and clock phase.
+ *  Mode 0: leading edge is rising edge, data sample on leading edge.
+ *  Mode 1: leading edge is rising edge, data sample on trailing edge.
+ *  Mode 2: leading edge is falling edge, data sample on leading edge.
+ *  Mode 3: leading edge is falling edge, data sample on trailing edge.
+ *  \param[in, out] dev Pointer to the SPI device instance.
+ *  \param[in] mode The SPI transfer mode.
+ *  \return Operation status.
+ *  \retval ERR_BUSY SPI is not ready to accept new setting.
+ *  \retval 0 Operation done successfully.
+ */
+int32_t _spi_m_async_set_mode(struct _spi_m_async_dev *dev, const enum spi_transfer_mode mode);
+
+/**
+ *  \brief Set SPI baudrate
+ *  \param[in, out] dev Pointer to the SPI device instance.
+ *  \param[in] baud_val The SPI baudrate value, see \ref _spi_calc_baud_val() on
+ *                  how it's generated.
+ *  \return Operation status.
+ *  \retval ERR_BUSY SPI is not ready to accept new setting.
+ *  \retval 0 Operation done successfully.
+ */
+int32_t _spi_m_async_set_baudrate(struct _spi_m_async_dev *dev, const uint32_t baud_val);
+
+/**
+ *  \brief Set SPI baudrate
+ *  \param[in, out] dev Pointer to the SPI device instance.
+ *  \param[in] char_size The character size, see \ref spi_char_size.
+ *  \return Operation status.
+ *  \retval ERR_INVALID_ARG The character size is not supported.
+ *  \retval ERR_BUSY SPI is not ready to accept new setting.
+ *  \retval 0 Operation done successfully.
+ */
+int32_t _spi_m_async_set_char_size(struct _spi_m_async_dev *dev, const enum spi_char_size char_size);
+
+/**
+ *  \brief Set SPI data order
+ *  \param[in, out] dev Pointer to the SPI device instance.
+ *  \param[in] dord SPI data order (LSB/MSB first).
+ *  \return Operation status.
+ *  \retval ERR_INVALID_ARG The character size is not supported.
+ *  \retval ERR_BUSY SPI is not ready to accept new setting.
+ *  \retval 0 Operation done successfully.
+ */
+int32_t _spi_m_async_set_data_order(struct _spi_m_async_dev *dev, const enum spi_data_order dord);
+
+/**
+ * \brief Enable interrupt on character output
+ *
+ * Enable interrupt when a new character can be written
+ * to the SPI device.
+ *
+ * \param[in] dev   Pointer to the SPI device instance
+ * \param[in] state true  = enable output interrupt
+ *                  false = disable output interrupt
+ *
+ * \return Status code
+ * \retval 0 Ok status
+ */
+int32_t _spi_m_async_enable_tx(struct _spi_m_async_dev *dev, bool state);
+
+/**
+ * \brief Enable interrupt on character input
+ *
+ * Enable interrupt when a new character is ready to be
+ * read from the SPI device.
+ *
+ * \param[in] dev  Pointer to the SPI device instance
+ * \param[in] state true  = enable input interrupts
+ *                  false = disable input interrupt
+ *
+ * \return Status code
+ * \retvat 0 OK Status
+ */
+int32_t _spi_m_async_enable_rx(struct _spi_m_async_dev *dev, bool state);
+
+/**
+ * \brief Enable interrupt on Slave Select (SS) rising
+ *
+ * \param[in] dev  Pointer to the SPI device instance
+ * \param[in] state true  = enable input interrupts
+ *                  false = disable input interrupt
+ *
+ * \return Status code
+ * \retvat 0 OK Status
+ */
+int32_t _spi_m_async_enable_ss_detect(struct _spi_m_async_dev *dev, bool state);
+
+/**
+ *  \brief Read one character to SPI device instance
+ *  \param[in, out] dev Pointer to the SPI device instance.
+ *
+ *  \return Character read from SPI module
+ */
+uint16_t _spi_m_async_read_one(struct _spi_m_async_dev *dev);
+
+/**
+ *  \brief Write one character to assigned buffer
+ *  \param[in, out] dev Pointer to the SPI device instance.
+ *  \param[in] data
+ *
+ *  \return Status code of write operation
+ *  \retval 0 Write operation OK
+ */
+int32_t _spi_m_async_write_one(struct _spi_m_async_dev *dev, uint16_t data);
+
+/**
+ *  \brief Register the SPI device callback
+ *  \param[in, out] dev Pointer to the SPI device instance.
+ *  \param[in] cb_type The callback type.
+ *  \param[in] func The callback function to register. NULL to disable callback.
+ *  \return Always 0.
+ */
+int32_t _spi_m_async_register_callback(struct _spi_m_async_dev *dev, const enum _spi_m_async_dev_cb_type cb_type,
+                                       const FUNC_PTR func);
+
+/**
+ * \brief Enable/disable SPI master interrupt
+ *
+ * param[in] device The pointer to SPI master device instance
+ * param[in] type The type of interrupt to disable/enable if applicable
+ * param[in] state Enable or disable
+ */
+void _spi_m_async_set_irq_state(struct _spi_m_async_dev *const device, const enum _spi_m_async_dev_cb_type type,
+                                const bool state);
+
+#ifdef __cplusplus
+}
+#endif
+
+/**@}*/
+#endif /* ifndef _HPL_SPI_M_ASYNC_H_INCLUDED */
diff --git a/atmel-samd/asf4/samd21/hal/include/hpl_spi_m_dma.h b/atmel-samd/asf4/samd21/hal/include/hpl_spi_m_dma.h
new file mode 100644
index 000000000..5e676fdc5
--- /dev/null
+++ b/atmel-samd/asf4/samd21/hal/include/hpl_spi_m_dma.h
@@ -0,0 +1,187 @@
+/**
+ * \file
+ *
+ * \brief SPI Master DMA related functionality declaration.
+ *
+ * Copyright (C) 2016 Atmel Corporation. All rights reserved.
+ *
+ * \asf_license_start
+ *
+ * \page License
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright notice,
+ *    this list of conditions and the following disclaimer.
+ *
+ * 2. Redistributions in binary form must reproduce the above copyright notice,
+ *    this list of conditions and the following disclaimer in the documentation
+ *    and/or other materials provided with the distribution.
+ *
+ * 3. The name of Atmel may not be used to endorse or promote products derived
+ *    from this software without specific prior written permission.
+ *
+ * 4. This software may only be redistributed and used in connection with an
+ *    Atmel microcontroller product.
+ *
+ * THIS SOFTWARE IS PROVIDED BY ATMEL "AS IS" AND ANY EXPRESS OR IMPLIED
+ * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
+ * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT ARE
+ * EXPRESSLY AND SPECIFICALLY DISCLAIMED. IN NO EVENT SHALL ATMEL BE LIABLE FOR
+ * ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+ * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
+ * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
+ * ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+ * POSSIBILITY OF SUCH DAMAGE.
+ *
+ * \asf_license_stop
+ *
+ */
+
+#ifndef _HPL_SPI_M_DMA_H_INCLUDED
+#define _HPL_SPI_M_DMA_H_INCLUDED
+
+#include <hpl_spi.h>
+#include <hpl_spi_dma.h>
+
+/**
+ * \addtogroup hpl_spi HPL SPI
+ *
+ *
+ *@{
+ */
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+/** Uses common SPI dma device driver. */
+#define _spi_m_dma_dev _spi_dma_dev
+
+#define _spi_m_dma_dev_cb_type _spi_dma_dev_cb_type
+
+/**
+ *  \brief Initialize SPI for access with interrupts
+ *  It will load default hardware configuration and software struct.
+ *  \param[in, out] dev Pointer to the SPI device instance.
+ *  \param[in] hw Pointer to the hardware base.
+ *  \return Operation status.
+ *  \retval ERR_INVALID_ARG Input parameter problem.
+ *  \retval ERR_BUSY SPI hardware not ready (resetting).
+ *  \retval ERR_DENIED SPI has been enabled.
+ *  \retval 0 ERR_NONE is operation done successfully.
+ */
+int32_t _spi_m_dma_init(struct _spi_m_dma_dev *dev, void *const hw);
+
+/**
+ *  \brief Initialize SPI for access with interrupts
+ *  Disable, reset the hardware and the software struct.
+ *  \param[in, out] dev Pointer to the SPI device instance.
+ *  \return Operation status.
+ *  \retval 0 ERR_NONE is operation done successfully.
+ */
+int32_t _spi_m_dma_deinit(struct _spi_m_dma_dev *dev);
+
+/**
+ *  \brief Enable SPI for access with interrupts
+ *  Enable the SPI and enable callback generation of receive and error
+ *  interrupts.
+ *  \param[in] dev Pointer to the SPI device instance.
+ *  \return Operation status.
+ *  \retval ERR_INVALID_ARG Input parameter problem.
+ *  \retval ERR_BUSY SPI hardware not ready (resetting).
+ *  \retval 0 ERR_NONE is operation done successfully.
+ */
+int32_t _spi_m_dma_enable(struct _spi_m_dma_dev *dev);
+
+/**
+ *  \brief Disable SPI for access without interrupts
+ *  Disable SPI and interrupts. Deactivate all CS pins if works as master.
+ *  \param[in] dev Pointer to the SPI device instance.
+ *  \return Operation status.
+ *  \retval 0 ERR_NONE is operation done successfully.
+ */
+int32_t _spi_m_dma_disable(struct _spi_m_dma_dev *dev);
+
+/**
+ *  \brief Set SPI transfer mode
+ *  Set SPI transfer mode (\ref spi_transfer_mode),
+ *  which controls clock polarity and clock phase.
+ *  Mode 0: leading edge is rising edge, data sample on leading edge.
+ *  Mode 1: leading edge is rising edge, data sample on trailing edge.
+ *  Mode 2: leading edge is falling edge, data sample on leading edge.
+ *  Mode 3: leading edge is falling edge, data sample on trailing edge.
+ *  \param[in] dev Pointer to the SPI device instance.
+ *  \param[in] mode The SPI transfer mode.
+ *  \return Operation status.
+ *  \retval ERR_BUSY SPI is not ready to accept new setting.
+ *  \retval 0 ERR_NONE is operation done successfully.
+ */
+int32_t _spi_m_dma_set_mode(struct _spi_m_dma_dev *dev, const enum spi_transfer_mode mode);
+
+/**
+ *  \brief Set SPI baudrate
+ *  \param[in] dev Pointer to the SPI device instance.
+ *  \param[in] baud_val The SPI baudrate value, see \ref _spi_calc_baud_val() on
+ *                  how it's generated.
+ *  \return Operation status.
+ *  \retval ERR_BUSY SPI is not ready to accept new setting.
+ *  \retval 0 Operation done successfully.
+ */
+int32_t _spi_m_dma_set_baudrate(struct _spi_m_dma_dev *dev, const uint32_t baud_val);
+
+/**
+ *  \brief Set SPI baudrate
+ *  \param[in, out] dev Pointer to the SPI device instance.
+ *  \param[in] char_size The character size, see \ref spi_char_size.
+ *  \return Operation status.
+ *  \retval ERR_INVALID_ARG The character size is not supported.
+ *  \retval ERR_BUSY SPI is not ready to accept new setting.
+ *  \retval 0 Operation done successfully.
+ */
+int32_t _spi_m_dma_set_char_size(struct _spi_m_dma_dev *dev, const enum spi_char_size char_size);
+
+/**
+ *  \brief Set SPI data order
+ *  \param[in] dev Pointer to the SPI device instance.
+ *  \param[in] dord SPI data order (LSB/MSB first).
+ *  \return Operation status.
+ *  \retval ERR_INVALID_ARG The character size is not supported.
+ *  \retval ERR_BUSY SPI is not ready to accept new setting.
+ *  \retval 0 Operation done successfully.
+ */
+int32_t _spi_m_dma_set_data_order(struct _spi_m_dma_dev *dev, const enum spi_data_order dord);
+
+/**
+ *  \brief Register the SPI device callback
+ *  \param[in] dev Pointer to the SPI device instance.
+ *  \param[in] cb_type The callback type.
+ *  \param[in] func The callback function to register. NULL to disable callback.
+ *  \return Always 0.
+ */
+void _spi_m_dma_register_callback(struct _spi_m_dma_dev *dev, enum _spi_dma_dev_cb_type, _spi_dma_cb_t func);
+
+/** \brief Do SPI data transfer (TX & RX) with DMA
+ *  Log the TX & RX buffers and transfer them in background. It never blocks.
+ *
+ *  \param[in] dev Pointer to the SPI device instance.
+ *  \param[in] txbuf Pointer to the transfer information (\ref spi_transfer).
+ *  \param[out] rxbuf Pointer to the receiver information (\ref spi_receive).
+ *  \param[in] length spi transfer data length.
+ *
+ *  \return Operation status.
+ *  \retval ERR_NONE Success.
+ *  \retval ERR_BUSY Busy.
+ */
+int32_t _spi_m_dma_transfer(struct _spi_m_dma_dev *dev, uint8_t const *txbuf, uint8_t *const rxbuf,
+                            const uint16_t length);
+
+#ifdef __cplusplus
+}
+#endif
+
+/**@}*/
+#endif /* ifndef _HPL_SPI_M_DMA_H_INCLUDED */
diff --git a/atmel-samd/asf4/samd21/hal/include/hpl_spi_m_sync.h b/atmel-samd/asf4/samd21/hal/include/hpl_spi_m_sync.h
new file mode 100644
index 000000000..fff1db4f2
--- /dev/null
+++ b/atmel-samd/asf4/samd21/hal/include/hpl_spi_m_sync.h
@@ -0,0 +1,171 @@
+/**
+ * \file
+ *
+ * \brief SPI related functionality declaration.
+ *
+ * Copyright (C) 2015 Atmel Corporation. All rights reserved.
+ *
+ * \asf_license_start
+ *
+ * \page License
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright notice,
+ *    this list of conditions and the following disclaimer.
+ *
+ * 2. Redistributions in binary form must reproduce the above copyright notice,
+ *    this list of conditions and the following disclaimer in the documentation
+ *    and/or other materials provided with the distribution.
+ *
+ * 3. The name of Atmel may not be used to endorse or promote products derived
+ *    from this software without specific prior written permission.
+ *
+ * 4. This software may only be redistributed and used in connection with an
+ *    Atmel microcontroller product.
+ *
+ * THIS SOFTWARE IS PROVIDED BY ATMEL "AS IS" AND ANY EXPRESS OR IMPLIED
+ * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
+ * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT ARE
+ * EXPRESSLY AND SPECIFICALLY DISCLAIMED. IN NO EVENT SHALL ATMEL BE LIABLE FOR
+ * ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+ * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
+ * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
+ * ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+ * POSSIBILITY OF SUCH DAMAGE.
+ *
+ * \asf_license_stop
+ *
+ */
+
+#ifndef _HPL_SPI_M_SYNC_H_INCLUDED
+#define _HPL_SPI_M_SYNC_H_INCLUDED
+
+#include <hpl_spi.h>
+#include <hpl_spi_sync.h>
+
+/**
+ * \addtogroup hpl_spi HPL SPI
+ *
+ *@{
+ */
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+/** Uses common SPI async device driver. */
+#define _spi_m_sync_dev _spi_sync_dev
+
+/**
+ *  \brief Initialize SPI for access without interrupts
+ *  It will load default hardware configuration and software struct.
+ *  \param[in, out] dev Pointer to the SPI device instance.
+ *  \param[in] hw Pointer to the hardware base.
+ *  \return Operation status.
+ *  \retval ERR_INVALID_ARG Input parameter problem.
+ *  \retval ERR_BUSY SPI hardware not ready (resetting).
+ *  \retval ERR_DENIED SPI has been enabled.
+ *  \retval 0 Operation done successfully.
+ */
+int32_t _spi_m_sync_init(struct _spi_m_sync_dev *dev, void *const hw);
+
+/**
+ *  \brief Deinitialize SPI
+ *  Disable, reset the hardware and the software struct.
+ *  \param[in, out] dev Pointer to the SPI device instance.
+ *  \return Operation status.
+ *  \retval 0 Operation done successfully.
+ */
+int32_t _spi_m_sync_deinit(struct _spi_m_sync_dev *dev);
+
+/**
+ *  \brief Enable SPI for access without interrupts
+ *  \param[in, out] dev Pointer to the SPI device instance.
+ *  \return Operation status.
+ *  \retval ERR_BUSY SPI hardware not ready (resetting).
+ *  \retval 0 Operation done successfully.
+ */
+int32_t _spi_m_sync_enable(struct _spi_m_sync_dev *dev);
+
+/**
+ *  \brief Disable SPI for access without interrupts
+ *  Disable SPI. Deactivate all CS pins if works as master.
+ *  \param[in, out] dev Pointer to the SPI device instance.
+ *  \return Operation status.
+ *  \retval 0 Operation done successfully.
+ */
+int32_t _spi_m_sync_disable(struct _spi_m_sync_dev *dev);
+
+/**
+ *  \brief Set SPI transfer mode
+ *  Set SPI transfer mode (\ref spi_transfer_mode),
+ *  which controls clock polarity and clock phase.
+ *  Mode 0: leading edge is rising edge, data sample on leading edge.
+ *  Mode 1: leading edge is rising edge, data sample on trailing edge.
+ *  Mode 2: leading edge is falling edge, data sample on leading edge.
+ *  Mode 3: leading edge is falling edge, data sample on trailing edge.
+ *  \param[in, out] dev Pointer to the SPI device instance.
+ *  \param[in] mode The SPI transfer mode.
+ *  \return Operation status.
+ *  \retval ERR_BUSY SPI is not ready to accept new setting.
+ *  \retval 0 Operation done successfully.
+ */
+int32_t _spi_m_sync_set_mode(struct _spi_m_sync_dev *dev, const enum spi_transfer_mode mode);
+
+/**
+ *  \brief Set SPI baudrate
+ *  \param[in, out] dev Pointer to the SPI device instance.
+ *  \param[in] baud_val The SPI baudrate value, see \ref _spi_calc_baud_val() on
+ *                  how it's generated.
+ *  \return Operation status.
+ *  \retval ERR_BUSY SPI is not ready to accept new setting.
+ *  \retval 0 Operation done successfully.
+ */
+int32_t _spi_m_sync_set_baudrate(struct _spi_m_sync_dev *dev, const uint32_t baud_val);
+
+/**
+ *  \brief Set SPI baudrate
+ *  \param[in, out] dev Pointer to the SPI device instance.
+ *  \param[in] char_size The character size, see \ref spi_char_size.
+ *  \return Operation status.
+ *  \retval ERR_INVALID_ARG The character size is not supported.
+ *  \retval ERR_BUSY SPI is not ready to accept new setting.
+ *  \retval 0 Operation done successfully.
+ */
+int32_t _spi_m_sync_set_char_size(struct _spi_m_sync_dev *dev, const enum spi_char_size char_size);
+
+/**
+ *  \brief Set SPI data order
+ *  \param[in, out] dev Pointer to the SPI device instance.
+ *  \param[in] dord SPI data order (LSB/MSB first).
+ *  \return Operation status.
+ *  \retval ERR_INVALID_ARG The character size is not supported.
+ *  \retval ERR_BUSY SPI is not ready to accept new setting.
+ *  \retval 0 Operation done successfully.
+ */
+int32_t _spi_m_sync_set_data_order(struct _spi_m_sync_dev *dev, const enum spi_data_order dord);
+
+/**
+ *  \brief Transfer the whole message without interrupt
+ *  Transfer the message, it will keep waiting until the message finish or
+ *  error.
+ *  \param[in, out] dev Pointer to the SPI device instance.
+ *  \param[in] msg Pointer to the message instance to process.
+ *  \return Error or number of characters transferred.
+ *  \retval ERR_BUSY SPI hardware is not ready to start transfer (not
+ *                   enabled, busy applying settings, ...).
+ *  \retval SPI_ERR_OVERFLOW Overflow error.
+ *  \retval >=0 Number of characters transferred.
+ */
+int32_t _spi_m_sync_trans(struct _spi_m_sync_dev *dev, const struct spi_msg *msg);
+
+#ifdef __cplusplus
+}
+#endif
+
+/**@}*/
+#endif /* ifndef _HPL_SPI_M_SYNC_H_INCLUDED */
diff --git a/atmel-samd/asf4/samd21/hal/include/hpl_spi_s_async.h b/atmel-samd/asf4/samd21/hal/include/hpl_spi_s_async.h
new file mode 100644
index 000000000..aec3c0a6f
--- /dev/null
+++ b/atmel-samd/asf4/samd21/hal/include/hpl_spi_s_async.h
@@ -0,0 +1,227 @@
+/**
+ * \file
+ *
+ * \brief SPI Slave Async related functionality declaration.
+ *
+ * Copyright (C) 2015 Atmel Corporation. All rights reserved.
+ *
+ * \asf_license_start
+ *
+ * \page License
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright notice,
+ *    this list of conditions and the following disclaimer.
+ *
+ * 2. Redistributions in binary form must reproduce the above copyright notice,
+ *    this list of conditions and the following disclaimer in the documentation
+ *    and/or other materials provided with the distribution.
+ *
+ * 3. The name of Atmel may not be used to endorse or promote products derived
+ *    from this software without specific prior written permission.
+ *
+ * 4. This software may only be redistributed and used in connection with an
+ *    Atmel microcontroller product.
+ *
+ * THIS SOFTWARE IS PROVIDED BY ATMEL "AS IS" AND ANY EXPRESS OR IMPLIED
+ * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
+ * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT ARE
+ * EXPRESSLY AND SPECIFICALLY DISCLAIMED. IN NO EVENT SHALL ATMEL BE LIABLE FOR
+ * ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+ * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
+ * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
+ * ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+ * POSSIBILITY OF SUCH DAMAGE.
+ *
+ * \asf_license_stop
+ *
+ */
+
+#ifndef _HPL_SPI_S_ASYNC_H_INCLUDED
+#define _HPL_SPI_S_ASYNC_H_INCLUDED
+
+#include <hpl_spi_async.h>
+
+/**
+ * \addtogroup hpl_spi HPL SPI
+ *
+ *
+ *@{
+ */
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+/** Uses common SPI async device driver. */
+#define _spi_s_async_dev _spi_async_dev
+
+#define _spi_s_async_dev_cb_type _spi_async_dev_cb_type
+
+/** Uses common SPI async device driver complete callback type. */
+#define _spi_s_async_dev_cb_complete_t _spi_async_dev_cb_complete_t
+
+/** Uses common SPI async device driver transfer callback type. */
+#define _spi_s_async_dev_cb_xfer_t _spi_async_dev_cb_xfer_t
+
+/**
+ *  \brief Initialize SPI for access with interrupts
+ *  It will load default hardware configuration and software struct.
+ *  \param[in, out] dev Pointer to the SPI device instance.
+ *  \param[in] hw Pointer to the hardware base.
+ *  \return Operation status.
+ *  \retval ERR_INVALID_ARG Input parameter problem.
+ *  \retval ERR_BUSY SPI hardware not ready (resetting).
+ *  \retval ERR_DENIED SPI has been enabled.
+ *  \retval 0 Operation done successfully.
+ */
+int32_t _spi_s_async_init(struct _spi_s_async_dev *dev, void *const hw);
+
+/**
+ *  \brief Initialize SPI for access with interrupts
+ *  Disable, reset the hardware and the software struct.
+ *  \param[in, out] dev Pointer to the SPI device instance.
+ *  \return Operation status.
+ *  \retval 0 Operation done successfully.
+ */
+int32_t _spi_s_async_deinit(struct _spi_s_async_dev *dev);
+
+/**
+ *  \brief Enable SPI for access with interrupts
+ *  Enable the SPI and enable callback generation of receive and error
+ *  interrupts.
+ *  \param[in, out] dev Pointer to the SPI device instance.
+ *  \return Operation status.
+ *  \retval ERR_INVALID_ARG Input parameter problem.
+ *  \retval ERR_BUSY SPI hardware not ready (resetting).
+ *  \retval 0 Operation done successfully.
+ */
+int32_t _spi_s_async_enable(struct _spi_s_async_dev *dev);
+
+/**
+ *  \brief Disable SPI for access without interrupts
+ *  Disable SPI and interrupts. Deactivate all CS pins if works as master.
+ *  \param[in, out] dev Pointer to the SPI device instance.
+ *  \return Operation status.
+ *  \retval 0 Operation done successfully.
+ */
+int32_t _spi_s_async_disable(struct _spi_s_async_dev *dev);
+
+/**
+ *  \brief Set SPI transfer mode
+ *  Set SPI transfer mode (\ref spi_transfer_mode),
+ *  which controls clock polarity and clock phase.
+ *  Mode 0: leading edge is rising edge, data sample on leading edge.
+ *  Mode 1: leading edge is rising edge, data sample on trailing edge.
+ *  Mode 2: leading edge is falling edge, data sample on leading edge.
+ *  Mode 3: leading edge is falling edge, data sample on trailing edge.
+ *  \param[in, out] dev Pointer to the SPI device instance.
+ *  \param[in] mode The SPI transfer mode.
+ *  \return Operation status.
+ *  \retval ERR_BUSY SPI is not ready to accept new setting.
+ *  \retval 0 Operation done successfully.
+ */
+int32_t _spi_s_async_set_mode(struct _spi_s_async_dev *dev, const enum spi_transfer_mode mode);
+
+/**
+ *  \brief Set SPI baudrate
+ *  \param[in, out] dev Pointer to the SPI device instance.
+ *  \param[in] char_size The character size, see \ref spi_char_size.
+ *  \return Operation status.
+ *  \retval ERR_INVALID_ARG The character size is not supported.
+ *  \retval ERR_BUSY SPI is not ready to accept new setting.
+ *  \retval 0 Operation done successfully.
+ */
+int32_t _spi_s_async_set_char_size(struct _spi_s_async_dev *dev, const enum spi_char_size char_size);
+
+/**
+ *  \brief Set SPI data order
+ *  \param[in, out] dev Pointer to the SPI device instance.
+ *  \param[in] dord SPI data order (LSB/MSB first).
+ *  \return Operation status.
+ *  \retval ERR_INVALID_ARG The character size is not supported.
+ *  \retval ERR_BUSY SPI is not ready to accept new setting.
+ *  \retval 0 Operation done successfully.
+ */
+int32_t _spi_s_async_set_data_order(struct _spi_s_async_dev *dev, const enum spi_data_order dord);
+
+/**
+ * \brief Enable interrupt on character output
+ *
+ * Enable interrupt when a new character can be written
+ * to the SPI device.
+ *
+ * \param[in] dev   Pointer to the SPI device instance
+ * \param[in] state true  = enable output interrupt
+ *                  false = disable output interrupt
+ *
+ * \return Status code
+ * \retval 0 Ok status
+ */
+int32_t _spi_s_async_enable_tx(struct _spi_s_async_dev *dev, bool state);
+
+/**
+ * \brief Enable interrupt on character input
+ *
+ * Enable interrupt when a new character is ready to be
+ * read from the SPI device.
+ *
+ * \param[in] dev  Pointer to the SPI device instance
+ * \param[in] state true  = enable input interrupts
+ *                  false = disable input interrupt
+ *
+ * \return Status code
+ * \retvat 0 OK Status
+ */
+int32_t _spi_s_async_enable_rx(struct _spi_s_async_dev *dev, bool state);
+
+/**
+ * \brief Enable interrupt on Slave Select (SS) rising
+ *
+ * \param[in] dev  Pointer to the SPI device instance
+ * \param[in] state true  = enable input interrupts
+ *                  false = disable input interrupt
+ *
+ * \return Status code
+ * \retvat 0 OK Status
+ */
+int32_t _spi_s_async_enable_ss_detect(struct _spi_s_async_dev *dev, bool state);
+
+/**
+ *  \brief Read one character to SPI device instance
+ *  \param[in, out] dev Pointer to the SPI device instance.
+ *
+ *  \return Character read from SPI module
+ */
+uint16_t _spi_s_async_read_one(struct _spi_s_async_dev *dev);
+
+/**
+ *  \brief Write one character to assigned buffer
+ *  \param[in, out] dev Pointer to the SPI device instance.
+ *  \param[in] data
+ *
+ *  \return Status code of write operation
+ *  \retval 0 Write operation OK
+ */
+int32_t _spi_s_async_write_one(struct _spi_s_async_dev *dev, uint16_t data);
+
+/**
+ *  \brief Register the SPI device callback
+ *  \param[in, out] dev Pointer to the SPI device instance.
+ *  \param[in] cb_type The callback type.
+ *  \param[in] func The callback function to register. NULL to disable callback.
+ *  \return Always 0.
+ */
+int32_t _spi_s_async_register_callback(struct _spi_s_async_dev *dev, const enum _spi_s_async_dev_cb_type cb_type,
+                                       const FUNC_PTR func);
+
+#ifdef __cplusplus
+}
+#endif
+
+/**@}*/
+#endif /* ifndef _HPL_SPI_S_ASYNC_H_INCLUDED */
diff --git a/atmel-samd/asf4/samd21/hal/include/hpl_spi_s_sync.h b/atmel-samd/asf4/samd21/hal/include/hpl_spi_s_sync.h
new file mode 100644
index 000000000..d42368697
--- /dev/null
+++ b/atmel-samd/asf4/samd21/hal/include/hpl_spi_s_sync.h
@@ -0,0 +1,237 @@
+/**
+ * \file
+ *
+ * \brief SPI related functionality declaration.
+ *
+ * Copyright (C) 2015 Atmel Corporation. All rights reserved.
+ *
+ * \asf_license_start
+ *
+ * \page License
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright notice,
+ *    this list of conditions and the following disclaimer.
+ *
+ * 2. Redistributions in binary form must reproduce the above copyright notice,
+ *    this list of conditions and the following disclaimer in the documentation
+ *    and/or other materials provided with the distribution.
+ *
+ * 3. The name of Atmel may not be used to endorse or promote products derived
+ *    from this software without specific prior written permission.
+ *
+ * 4. This software may only be redistributed and used in connection with an
+ *    Atmel microcontroller product.
+ *
+ * THIS SOFTWARE IS PROVIDED BY ATMEL "AS IS" AND ANY EXPRESS OR IMPLIED
+ * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
+ * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT ARE
+ * EXPRESSLY AND SPECIFICALLY DISCLAIMED. IN NO EVENT SHALL ATMEL BE LIABLE FOR
+ * ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+ * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
+ * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
+ * ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+ * POSSIBILITY OF SUCH DAMAGE.
+ *
+ * \asf_license_stop
+ *
+ */
+
+#ifndef _HPL_SPI_S_SYNC_H_INCLUDED
+#define _HPL_SPI_S_SYNC_H_INCLUDED
+
+#include <hpl_spi_sync.h>
+
+/**
+ * \addtogroup hpl_spi HPL SPI
+ *
+ *@{
+ */
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+/** Uses common SPI async device driver. */
+#define _spi_s_sync_dev _spi_sync_dev
+
+/**
+ *  \brief Initialize SPI for access without interrupts
+ *  It will load default hardware configuration and software struct.
+ *  \param[in, out] dev Pointer to the SPI device instance.
+ *  \param[in] hw Pointer to the hardware base.
+ *  \return Operation status.
+ *  \retval ERR_INVALID_ARG Input parameter problem.
+ *  \retval ERR_BUSY SPI hardware not ready (resetting).
+ *  \retval ERR_DENIED SPI has been enabled.
+ *  \retval 0 Operation done successfully.
+ */
+int32_t _spi_s_sync_init(struct _spi_s_sync_dev *dev, void *const hw);
+
+/**
+ *  \brief Initialize SPI for access with interrupts
+ *  Disable, reset the hardware and the software struct.
+ *  \param[in, out] dev Pointer to the SPI device instance.
+ *  \return Operation status.
+ *  \retval 0 Operation done successfully.
+ */
+int32_t _spi_s_sync_deinit(struct _spi_s_sync_dev *dev);
+
+/**
+ *  \brief Enable SPI for access without interrupts
+ *  \param[in, out] dev Pointer to the SPI device instance.
+ *  \return Operation status.
+ *  \retval ERR_BUSY SPI hardware not ready (resetting).
+ *  \retval 0 Operation done successfully.
+ */
+int32_t _spi_s_sync_enable(struct _spi_s_sync_dev *dev);
+
+/**
+ *  \brief Disable SPI for access without interrupts
+ *  Disable SPI. Deactivate all CS pins if works as master.
+ *  \param[in, out] dev Pointer to the SPI device instance.
+ *  \return Operation status.
+ *  \retval 0 Operation done successfully.
+ */
+int32_t _spi_s_sync_disable(struct _spi_s_sync_dev *dev);
+
+/**
+ *  \brief Set SPI transfer mode
+ *  Set SPI transfer mode (\ref spi_transfer_mode),
+ *  which controls clock polarity and clock phase.
+ *  Mode 0: leading edge is rising edge, data sample on leading edge.
+ *  Mode 1: leading edge is rising edge, data sample on trailing edge.
+ *  Mode 2: leading edge is falling edge, data sample on leading edge.
+ *  Mode 3: leading edge is falling edge, data sample on trailing edge.
+ *  \param[in, out] dev Pointer to the SPI device instance.
+ *  \param[in] mode The SPI transfer mode.
+ *  \return Operation status.
+ *  \retval ERR_BUSY SPI is not ready to accept new setting.
+ *  \retval 0 Operation done successfully.
+ */
+int32_t _spi_s_sync_set_mode(struct _spi_s_sync_dev *dev, const enum spi_transfer_mode mode);
+
+/**
+ *  \brief Set SPI baudrate
+ *  \param[in, out] dev Pointer to the SPI device instance.
+ *  \param[in] char_size The character size, see \ref spi_char_size.
+ *  \return Operation status.
+ *  \retval ERR_INVALID_ARG The character size is not supported.
+ *  \retval ERR_BUSY SPI is not ready to accept new setting.
+ *  \retval 0 Operation done successfully.
+ */
+int32_t _spi_s_sync_set_char_size(struct _spi_s_sync_dev *dev, const enum spi_char_size char_size);
+
+/**
+ *  \brief Set SPI data order
+ *  \param[in, out] dev Pointer to the SPI device instance.
+ *  \param[in] dord SPI data order (LSB/MSB first).
+ *  \return Operation status.
+ *  \retval ERR_INVALID_ARG The character size is not supported.
+ *  \retval ERR_BUSY SPI is not ready to accept new setting.
+ *  \retval 0 Operation done successfully.
+ */
+int32_t _spi_s_sync_set_data_order(struct _spi_s_sync_dev *dev, const enum spi_data_order dord);
+
+/**
+ * \brief Enable interrupt on character output
+ *
+ * Enable interrupt when a new character can be written
+ * to the SPI device.
+ *
+ * \param[in] dev   Pointer to the SPI device instance
+ * \param[in] state true  = enable output interrupt
+ *                  false = disable output interrupt
+ *
+ * \return Status code
+ * \retval 0 Ok status
+ */
+int32_t _spi_s_sync_enable_tx(struct _spi_s_sync_dev *dev, bool state);
+
+/**
+ * \brief Enable interrupt on character input
+ *
+ * Enable interrupt when a new character is ready to be
+ * read from the SPI device.
+ *
+ * \param[in] dev  Pointer to the SPI device instance
+ * \param[in] state true  = enable input interrupts
+ *                  false = disable input interrupt
+ *
+ * \return Status code
+ * \retval 0 OK Status
+ */
+int32_t _spi_s_sync_enable_rx(struct _spi_s_sync_dev *dev, bool state);
+
+/**
+ *  \brief Read one character to SPI device instance
+ *  \param[in, out] dev Pointer to the SPI device instance.
+ *
+ *  \return Character read from SPI module
+ */
+uint16_t _spi_s_sync_read_one(struct _spi_s_sync_dev *dev);
+
+/**
+ *  \brief Write one character to assigned buffer
+ *  \param[in, out] dev Pointer to the SPI device instance.
+ *  \param[in] data
+ *
+ *  \return Status code of write operation
+ *  \retval 0 Write operation OK
+ */
+int32_t _spi_s_sync_write_one(struct _spi_s_sync_dev *dev, uint16_t data);
+
+/**
+ * \brief Check if TX ready
+ *
+ * \param[in] dev  Pointer to the SPI device instance
+ *
+ * \return TX ready state
+ * \retval true TX ready
+ * \retval false TX not ready
+ */
+bool _spi_s_sync_is_tx_ready(struct _spi_s_sync_dev *dev);
+
+/**
+ * \brief Check if RX character ready
+ *
+ * \param[in] dev  Pointer to the SPI device instance
+ *
+ * \return RX character ready state
+ * \retval true RX character ready
+ * \retval false RX character not ready
+ */
+bool _spi_s_sync_is_rx_ready(struct _spi_s_sync_dev *dev);
+
+/**
+ * \brief Check if SS deactiviation detected
+ *
+ * \param[in] dev  Pointer to the SPI device instance
+ *
+ * \return SS deactiviation state
+ * \retval true SS deactiviation detected
+ * \retval false SS deactiviation not detected
+ */
+bool _spi_s_sync_is_ss_deactivated(struct _spi_s_sync_dev *dev);
+
+/**
+ * \brief Check if error is detected
+ *
+ * \param[in] dev  Pointer to the SPI device instance
+ *
+ * \return Error detection state
+ * \retval true Error detected
+ * \retval false Error not detected
+ */
+bool _spi_s_sync_is_error(struct _spi_s_sync_dev *dev);
+
+#ifdef __cplusplus
+}
+#endif
+
+/**@}*/
+#endif /* ifndef _HPL_SPI_S_SYNC_H_INCLUDED */
diff --git a/atmel-samd/asf4/samd21/hal/include/hpl_spi_sync.h b/atmel-samd/asf4/samd21/hal/include/hpl_spi_sync.h
new file mode 100644
index 000000000..a231a0bb5
--- /dev/null
+++ b/atmel-samd/asf4/samd21/hal/include/hpl_spi_sync.h
@@ -0,0 +1,80 @@
+/**
+ * \file
+ *
+ * \brief Common SPI related functionality declaration.
+ *
+ * Copyright (C) 2015 Atmel Corporation. All rights reserved.
+ *
+ * \asf_license_start
+ *
+ * \page License
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright notice,
+ *    this list of conditions and the following disclaimer.
+ *
+ * 2. Redistributions in binary form must reproduce the above copyright notice,
+ *    this list of conditions and the following disclaimer in the documentation
+ *    and/or other materials provided with the distribution.
+ *
+ * 3. The name of Atmel may not be used to endorse or promote products derived
+ *    from this software without specific prior written permission.
+ *
+ * 4. This software may only be redistributed and used in connection with an
+ *    Atmel microcontroller product.
+ *
+ * THIS SOFTWARE IS PROVIDED BY ATMEL "AS IS" AND ANY EXPRESS OR IMPLIED
+ * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
+ * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT ARE
+ * EXPRESSLY AND SPECIFICALLY DISCLAIMED. IN NO EVENT SHALL ATMEL BE LIABLE FOR
+ * ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+ * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
+ * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
+ * ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+ * POSSIBILITY OF SUCH DAMAGE.
+ *
+ * \asf_license_stop
+ *
+ */
+
+#ifndef _HPL_SPI_SYNC_H_INCLUDED
+#define _HPL_SPI_SYNC_H_INCLUDED
+
+#include <compiler.h>
+#include <utils.h>
+
+#include <hpl_spi.h>
+
+/**
+ * \addtogroup hpl_spi HPL SPI
+ *
+ * \section hpl_spi_rev Revision History
+ * - v1.0.0 Initial Release
+ *
+ *@{
+ */
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+/** SPI driver to support sync HAL */
+struct _spi_sync_dev {
+	/** Pointer to the hardware base or private data for special device. */
+	void *prvt;
+	/** Data size, number of bytes for each character */
+	uint8_t char_size;
+	/** Dummy byte used in master mode when reading the slave */
+	uint16_t dummy_byte;
+};
+
+#ifdef __cplusplus
+}
+#endif
+
+/**@}*/
+#endif /* ifndef _HPL_SPI_SYNC_H_INCLUDED */
diff --git a/atmel-samd/asf4/samd21/hal/include/hpl_time_measure.h b/atmel-samd/asf4/samd21/hal/include/hpl_time_measure.h
new file mode 100644
index 000000000..7502a5910
--- /dev/null
+++ b/atmel-samd/asf4/samd21/hal/include/hpl_time_measure.h
@@ -0,0 +1,104 @@
+/**
+ * \file
+ *
+ * \brief Time measure related functionality declaration.
+ *
+ * Copyright (C) 2014 Atmel Corporation. All rights reserved.
+ *
+ * \asf_license_start
+ *
+ * \page License
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright notice,
+ *    this list of conditions and the following disclaimer.
+ *
+ * 2. Redistributions in binary form must reproduce the above copyright notice,
+ *    this list of conditions and the following disclaimer in the documentation
+ *    and/or other materials provided with the distribution.
+ *
+ * 3. The name of Atmel may not be used to endorse or promote products derived
+ *    from this software without specific prior written permission.
+ *
+ * 4. This software may only be redistributed and used in connection with an
+ *    Atmel microcontroller product.
+ *
+ * THIS SOFTWARE IS PROVIDED BY ATMEL "AS IS" AND ANY EXPRESS OR IMPLIED
+ * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
+ * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT ARE
+ * EXPRESSLY AND SPECIFICALLY DISCLAIMED. IN NO EVENT SHALL ATMEL BE LIABLE FOR
+ * ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+ * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
+ * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
+ * ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+ * POSSIBILITY OF SUCH DAMAGE.
+ *
+ * \asf_license_stop
+ *
+ */
+
+#ifndef _HPL_TIME_MEASURE_H_INCLUDED
+#define _HPL_TIME_MEASURE_H_INCLUDED
+
+/**
+ * \addtogroup HPL Time measure
+ *
+ * \section hpl_time_measure_rev Revision History
+ * - v1.0.0 Initial Release
+ *
+ *@{
+ */
+
+#include <compiler.h>
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+/**
+ * \brief System time type
+ */
+typedef uint32_t system_time_t;
+
+/**
+ * \name HPL functions
+ */
+//@{
+/**
+ * \brief Initialize system time module
+ *
+ * \param[in] hw The pointer to hardware instance to initialize
+ */
+void _system_time_init(void *const hw);
+
+/**
+ * \brief Deinitialize system time module
+ *
+ * \param[in] hw The pointer to hardware instance to initialize
+ */
+void _system_time_deinit(void *const hw);
+
+/**
+ * \brief Get system time
+ *
+ * \param[in] hw The pointer to hardware instance to initialize
+ */
+system_time_t _system_time_get(const void *const hw);
+
+/**
+ * \brief Get maximum possible system time
+ *
+ * \param[in] hw The pointer to hardware instance to initialize
+ */
+system_time_t _system_time_get_max_time_value(const void *const hw);
+//@}
+
+#ifdef __cplusplus
+}
+#endif
+/**@}*/
+#endif /* _HPL_TIME_MEASURE_H_INCLUDED */
diff --git a/atmel-samd/asf4/samd21/hal/include/hpl_timer.h b/atmel-samd/asf4/samd21/hal/include/hpl_timer.h
new file mode 100644
index 000000000..d2434e8c4
--- /dev/null
+++ b/atmel-samd/asf4/samd21/hal/include/hpl_timer.h
@@ -0,0 +1,170 @@
+/**
+ * \file
+ *
+ * \brief Timer related functionality declaration.
+ *
+ * Copyright (C) 2014 - 2016 Atmel Corporation. All rights reserved.
+ *
+ * \asf_license_start
+ *
+ * \page License
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright notice,
+ *    this list of conditions and the following disclaimer.
+ *
+ * 2. Redistributions in binary form must reproduce the above copyright notice,
+ *    this list of conditions and the following disclaimer in the documentation
+ *    and/or other materials provided with the distribution.
+ *
+ * 3. The name of Atmel may not be used to endorse or promote products derived
+ *    from this software without specific prior written permission.
+ *
+ * 4. This software may only be redistributed and used in connection with an
+ *    Atmel microcontroller product.
+ *
+ * THIS SOFTWARE IS PROVIDED BY ATMEL "AS IS" AND ANY EXPRESS OR IMPLIED
+ * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
+ * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT ARE
+ * EXPRESSLY AND SPECIFICALLY DISCLAIMED. IN NO EVENT SHALL ATMEL BE LIABLE FOR
+ * ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+ * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
+ * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
+ * ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+ * POSSIBILITY OF SUCH DAMAGE.
+ *
+ * \asf_license_stop
+ *
+ */
+
+#ifndef _HPL_TIMER_H_INCLUDED
+#define _HPL_TIMER_H_INCLUDED
+
+/**
+ * \addtogroup HPL Timer
+ *
+ * \section hpl_timer_rev Revision History
+ * - v1.0.0 Initial Release
+ *
+ *@{
+ */
+
+#include <compiler.h>
+#include <hpl_irq.h>
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+/**
+ * \brief Timer device structure
+ *
+ * The Timer device structure forward declaration.
+ */
+struct _timer_device;
+
+/**
+ * \brief Timer interrupt callbacks
+ */
+struct _timer_callbacks {
+	void (*period_expired)(struct _timer_device *device);
+};
+
+/**
+ * \brief Timer device structure
+ */
+struct _timer_device {
+	struct _timer_callbacks timer_cb;
+	struct _irq_descriptor  irq;
+	void *                  hw;
+};
+
+/**
+ * \brief Timer functions, pointers to low-level functions
+ */
+struct _timer_hpl_interface {
+	int32_t (*init)(struct _timer_device *const device, void *const hw);
+	void (*deinit)(struct _timer_device *const device);
+	void (*start_timer)(struct _timer_device *const device);
+	void (*stop_timer)(struct _timer_device *const device);
+	void (*set_timer_period)(struct _timer_device *const device, const uint32_t clock_cycles);
+	uint32_t (*get_period)(const struct _timer_device *const device);
+	bool (*is_timer_started)(const struct _timer_device *const device);
+	void (*set_timer_irq)(struct _timer_device *const device);
+};
+/**
+ * \brief Initialize TCC
+ *
+ * This function does low level TCC configuration.
+ *
+ * \param[in] device The pointer to timer device instance
+ * \param[in] hw The pointer to hardware instance
+ *
+ * \return Initialization status.
+ */
+int32_t _timer_init(struct _timer_device *const device, void *const hw);
+
+/**
+ * \brief Deinitialize TCC
+ *
+ * \param[in] device The pointer to timer device instance
+ */
+void _timer_deinit(struct _timer_device *const device);
+
+/**
+ * \brief Start hardware timer
+ *
+ * \param[in] device The pointer to timer device instance
+ */
+void _timer_start(struct _timer_device *const device);
+
+/**
+ * \brief Stop hardware timer
+ *
+ * \param[in] device The pointer to timer device instance
+ */
+void _timer_stop(struct _timer_device *const device);
+
+/**
+ * \brief Set timer period
+ *
+ * \param[in] device The pointer to timer device instance
+ */
+void _timer_set_period(struct _timer_device *const device, const uint32_t clock_cycles);
+
+/**
+ * \brief Retrieve timer period
+ *
+ * \param[in] device The pointer to timer device instance
+ *
+ * \return Timer period
+ */
+uint32_t _timer_get_period(const struct _timer_device *const device);
+
+/**
+ * \brief Check if timer is running
+ *
+ * \param[in] device The pointer to timer device instance
+ *
+ * \return Check status.
+ * \retval true The given timer is running
+ * \retval false The given timer is not running
+ */
+bool _timer_is_started(const struct _timer_device *const device);
+
+/**
+ * \brief Set timer IRQ
+ *
+ * \param[in] device The pointer to timer device instance
+ */
+void _timer_set_irq(struct _timer_device *const device);
+
+#ifdef __cplusplus
+}
+#endif
+/**@}*/
+#endif /* _HPL_TIMER_H_INCLUDED */
diff --git a/atmel-samd/asf4/samd21/hal/include/hpl_usart.h b/atmel-samd/asf4/samd21/hal/include/hpl_usart.h
new file mode 100644
index 000000000..f6235de93
--- /dev/null
+++ b/atmel-samd/asf4/samd21/hal/include/hpl_usart.h
@@ -0,0 +1,123 @@
+/**
+ * \file
+ *
+ * \brief USART related functionality declaration.
+ *
+ * Copyright (C) 2014 Atmel Corporation. All rights reserved.
+ *
+ * \asf_license_start
+ *
+ * \page License
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright notice,
+ *    this list of conditions and the following disclaimer.
+ *
+ * 2. Redistributions in binary form must reproduce the above copyright notice,
+ *    this list of conditions and the following disclaimer in the documentation
+ *    and/or other materials provided with the distribution.
+ *
+ * 3. The name of Atmel may not be used to endorse or promote products derived
+ *    from this software without specific prior written permission.
+ *
+ * 4. This software may only be redistributed and used in connection with an
+ *    Atmel microcontroller product.
+ *
+ * THIS SOFTWARE IS PROVIDED BY ATMEL "AS IS" AND ANY EXPRESS OR IMPLIED
+ * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
+ * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT ARE
+ * EXPRESSLY AND SPECIFICALLY DISCLAIMED. IN NO EVENT SHALL ATMEL BE LIABLE FOR
+ * ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+ * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
+ * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
+ * ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+ * POSSIBILITY OF SUCH DAMAGE.
+ *
+ * \asf_license_stop
+ *
+ */
+
+#ifndef _HPL_USART_H_INCLUDED
+#define _HPL_USART_H_INCLUDED
+
+/**
+ * \addtogroup HPL USART SYNC
+ *
+ * \section hpl_usart_sync_rev Revision History
+ * - v1.0.0 Initial Release
+ *
+ *@{
+ */
+
+#include <compiler.h>
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+/**
+ * \brief USART flow control state
+ */
+union usart_flow_control_state {
+	struct {
+		uint8_t cts : 1;
+		uint8_t rts : 1;
+		uint8_t unavailable : 1;
+		uint8_t reserved : 5;
+	} bit;
+	uint8_t value;
+};
+
+/**
+ * \brief USART baud rate mode
+ */
+enum usart_baud_rate_mode { USART_BAUDRATE_ASYNCH_ARITHMETIC, USART_BAUDRATE_ASYNCH_FRACTIONAL, USART_BAUDRATE_SYNCH };
+
+/**
+ * \brief USART data order
+ */
+enum usart_data_order { USART_DATA_ORDER_MSB = 0, USART_DATA_ORDER_LSB = 1 };
+
+/**
+ * \brief USART mode
+ */
+enum usart_mode { USART_MODE_ASYNCHRONOUS = 0, USART_MODE_SYNCHRONOUS = 1 };
+
+/**
+ * \brief USART parity
+ */
+enum usart_parity {
+	USART_PARITY_EVEN  = 0,
+	USART_PARITY_ODD   = 1,
+	USART_PARITY_NONE  = 2,
+	USART_PARITY_SPACE = 3,
+	USART_PARITY_MARK  = 4
+};
+
+/**
+ * \brief USART stop bits mode
+ */
+enum usart_stop_bits { USART_STOP_BITS_ONE = 0, USART_STOP_BITS_TWO = 1, USART_STOP_BITS_ONE_P_FIVE = 2 };
+
+/**
+ * \brief USART character size
+ */
+enum usart_character_size {
+	USART_CHARACTER_SIZE_8BITS = 0,
+	USART_CHARACTER_SIZE_9BITS = 1,
+	USART_CHARACTER_SIZE_5BITS = 5,
+	USART_CHARACTER_SIZE_6BITS = 6,
+	USART_CHARACTER_SIZE_7BITS = 7
+};
+
+//@}
+
+#ifdef __cplusplus
+}
+#endif
+/**@}*/
+#endif /* _HPL_USART_H_INCLUDED */
diff --git a/atmel-samd/asf4/samd21/hal/include/hpl_usart_async.h b/atmel-samd/asf4/samd21/hal/include/hpl_usart_async.h
new file mode 100644
index 000000000..1bcb3da44
--- /dev/null
+++ b/atmel-samd/asf4/samd21/hal/include/hpl_usart_async.h
@@ -0,0 +1,280 @@
+/**
+ * \file
+ *
+ * \brief USART related functionality declaration.
+ *
+ * Copyright (C) 2014 Atmel Corporation. All rights reserved.
+ *
+ * \asf_license_start
+ *
+ * \page License
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright notice,
+ *    this list of conditions and the following disclaimer.
+ *
+ * 2. Redistributions in binary form must reproduce the above copyright notice,
+ *    this list of conditions and the following disclaimer in the documentation
+ *    and/or other materials provided with the distribution.
+ *
+ * 3. The name of Atmel may not be used to endorse or promote products derived
+ *    from this software without specific prior written permission.
+ *
+ * 4. This software may only be redistributed and used in connection with an
+ *    Atmel microcontroller product.
+ *
+ * THIS SOFTWARE IS PROVIDED BY ATMEL "AS IS" AND ANY EXPRESS OR IMPLIED
+ * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
+ * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT ARE
+ * EXPRESSLY AND SPECIFICALLY DISCLAIMED. IN NO EVENT SHALL ATMEL BE LIABLE FOR
+ * ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+ * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
+ * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
+ * ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+ * POSSIBILITY OF SUCH DAMAGE.
+ *
+ * \asf_license_stop
+ *
+ */
+
+#ifndef _HPL_USART_ASYNC_H_INCLUDED
+#define _HPL_USART_ASYNC_H_INCLUDED
+
+/**
+ * \addtogroup HPL USART
+ *
+ * \section hpl_usart_rev Revision History
+ * - v1.0.0 Initial Release
+ *
+ *@{
+ */
+
+#include "hpl_usart.h"
+#include "hpl_irq.h"
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+/**
+ * \brief USART callback types
+ */
+enum _usart_async_callback_type { USART_ASYNC_BYTE_SENT, USART_ASYNC_RX_DONE, USART_ASYNC_TX_DONE, USART_ASYNC_ERROR };
+
+/**
+ * \brief USART device structure
+ *
+ * The USART device structure forward declaration.
+ */
+struct _usart_async_device;
+
+/**
+ * \brief USART interrupt callbacks
+ */
+struct _usart_async_callbacks {
+	void (*tx_byte_sent)(struct _usart_async_device *device);
+	void (*rx_done_cb)(struct _usart_async_device *device, uint8_t data);
+	void (*tx_done_cb)(struct _usart_async_device *device);
+	void (*error_cb)(struct _usart_async_device *device);
+};
+
+/**
+ * \brief USART descriptor device structure
+ */
+struct _usart_async_device {
+	struct _usart_async_callbacks usart_cb;
+	struct _irq_descriptor        irq;
+	void *                        hw;
+};
+/**
+ * \name HPL functions
+ */
+//@{
+/**
+ * \brief Initialize asynchronous USART
+ *
+ * This function does low level USART configuration.
+ *
+ * \param[in] device The pointer to USART device instance
+ * \param[in] hw The pointer to hardware instance
+ *
+ * \return Initialization status
+ */
+int32_t _usart_async_init(struct _usart_async_device *const device, void *const hw);
+
+/**
+ * \brief Deinitialize USART
+ *
+ * This function closes the given USART by disabling its clock.
+ *
+ * \param[in] device The pointer to USART device instance
+ */
+void _usart_async_deinit(struct _usart_async_device *const device);
+
+/**
+ * \brief Enable usart module
+ *
+ * This function will enable the usart module
+ *
+ * \param[in] device The pointer to USART device instance
+ */
+void _usart_async_enable(struct _usart_async_device *const device);
+
+/**
+ * \brief Disable usart module
+ *
+ * This function will disable the usart module
+ *
+ * \param[in] device The pointer to USART device instance
+ */
+void _usart_async_disable(struct _usart_async_device *const device);
+
+/**
+ * \brief Calculate baud rate register value
+ *
+ * \param[in] baud Required baud rate
+ * \param[in] clock_rate clock frequency
+ * \param[in] samples The number of samples
+ * \param[in] mode USART mode
+ * \param[in] fraction A fraction value
+ *
+ * \return Calculated baud rate register value
+ */
+uint16_t _usart_async_calculate_baud_rate(const uint32_t baud, const uint32_t clock_rate, const uint8_t samples,
+                                          const enum usart_baud_rate_mode mode, const uint8_t fraction);
+
+/**
+ * \brief Set baud rate
+ *
+ * \param[in] device The pointer to USART device instance
+ * \param[in] baud_rate A baud rate to set
+ */
+void _usart_async_set_baud_rate(struct _usart_async_device *const device, const uint32_t baud_rate);
+
+/**
+ * \brief Set data order
+ *
+ * \param[in] device The pointer to USART device instance
+ * \param[in] order A data order to set
+ */
+void _usart_async_set_data_order(struct _usart_async_device *const device, const enum usart_data_order order);
+
+/**
+ * \brief Set mode
+ *
+ * \param[in] device The pointer to USART device instance
+ * \param[in] mode A mode to set
+ */
+void _usart_async_set_mode(struct _usart_async_device *const device, const enum usart_mode mode);
+
+/**
+ * \brief Set parity
+ *
+ * \param[in] device The pointer to USART device instance
+ * \param[in] parity A parity to set
+ */
+void _usart_async_set_parity(struct _usart_async_device *const device, const enum usart_parity parity);
+
+/**
+ * \brief Set stop bits mode
+ *
+ * \param[in] device The pointer to USART device instance
+ * \param[in] stop_bits A stop bits mode to set
+ */
+void _usart_async_set_stop_bits(struct _usart_async_device *const device, const enum usart_stop_bits stop_bits);
+
+/**
+ * \brief Set character size
+ *
+ * \param[in] device The pointer to USART device instance
+ * \param[in] size A character size to set
+ */
+void _usart_async_set_character_size(struct _usart_async_device *const device, const enum usart_character_size size);
+
+/**
+ * \brief Retrieve usart status
+ *
+ * \param[in] device The pointer to USART device instance
+ */
+uint32_t _usart_async_get_status(const struct _usart_async_device *const device);
+
+/**
+ * \brief Write a byte to the given USART instance
+ *
+ * \param[in] device The pointer to USART device instance
+ * \param[in] data Data to write
+ */
+void _usart_async_write_byte(struct _usart_async_device *const device, uint8_t data);
+
+/**
+ * \brief Check if USART is ready to send next byte
+ *
+ * \param[in] device The pointer to USART device instance
+ *
+ * \return Status of the ready check.
+ * \retval true if the USART is ready to send next byte
+ * \retval false if the USART is not ready to send next byte
+ */
+bool _usart_async_is_byte_sent(const struct _usart_async_device *const device);
+
+/**
+ * \brief Set the state of flow control pins
+ *
+ * \param[in] device The pointer to USART device instance
+ * \param[in] state - A state of flow control pins to set
+ */
+void _usart_async_set_flow_control_state(struct _usart_async_device *const    device,
+                                         const union usart_flow_control_state state);
+
+/**
+ * \brief Retrieve the state of flow control pins
+ *
+ * This function retrieves the of flow control pins.
+ *
+ * \return USART_FLOW_CONTROL_STATE_UNAVAILABLE.
+ */
+union usart_flow_control_state _usart_async_get_flow_control_state(const struct _usart_async_device *const device);
+
+/**
+ * \brief Enable data register empty interrupt
+ *
+ * \param[in] device The pointer to USART device instance
+ */
+void _usart_async_enable_byte_sent_irq(struct _usart_async_device *const device);
+
+/**
+ * \brief Enable transmission complete interrupt
+ *
+ * \param[in] device The pointer to USART device instance
+ */
+void _usart_async_enable_tx_done_irq(struct _usart_async_device *const device);
+
+/**
+ * \brief Retrieve ordinal number of the given USART hardware instance
+ *
+ * \param[in] device The pointer to USART device instance
+ *
+ * \return The ordinal number of the given USART hardware instance
+ */
+uint8_t _usart_async_get_hardware_index(const struct _usart_async_device *const device);
+
+/**
+ * \brief Enable/disable USART interrupt
+ *
+ * param[in] device The pointer to USART device instance
+ * param[in] type The type of interrupt to disable/enable if applicable
+ * param[in] state Enable or disable
+ */
+void _usart_async_set_irq_state(struct _usart_async_device *const device, const enum _usart_async_callback_type type,
+                                const bool state);
+//@}
+
+#ifdef __cplusplus
+}
+#endif
+/**@}*/
+#endif /* _HPL_USART_ASYNC_H_INCLUDED */
diff --git a/atmel-samd/asf4/samd21/hal/include/hpl_usart_sync.h b/atmel-samd/asf4/samd21/hal/include/hpl_usart_sync.h
new file mode 100644
index 000000000..c7881583c
--- /dev/null
+++ b/atmel-samd/asf4/samd21/hal/include/hpl_usart_sync.h
@@ -0,0 +1,253 @@
+/**
+ * \file
+ *
+ * \brief USART related functionality declaration.
+ *
+ * Copyright (C) 2014 Atmel Corporation. All rights reserved.
+ *
+ * \asf_license_start
+ *
+ * \page License
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright notice,
+ *    this list of conditions and the following disclaimer.
+ *
+ * 2. Redistributions in binary form must reproduce the above copyright notice,
+ *    this list of conditions and the following disclaimer in the documentation
+ *    and/or other materials provided with the distribution.
+ *
+ * 3. The name of Atmel may not be used to endorse or promote products derived
+ *    from this software without specific prior written permission.
+ *
+ * 4. This software may only be redistributed and used in connection with an
+ *    Atmel microcontroller product.
+ *
+ * THIS SOFTWARE IS PROVIDED BY ATMEL "AS IS" AND ANY EXPRESS OR IMPLIED
+ * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
+ * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT ARE
+ * EXPRESSLY AND SPECIFICALLY DISCLAIMED. IN NO EVENT SHALL ATMEL BE LIABLE FOR
+ * ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+ * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
+ * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
+ * ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+ * POSSIBILITY OF SUCH DAMAGE.
+ *
+ * \asf_license_stop
+ *
+ */
+
+#ifndef _HPL_SYNC_USART_H_INCLUDED
+#define _HPL_SYNC_USART_H_INCLUDED
+
+/**
+ * \addtogroup HPL USART SYNC
+ *
+ * \section hpl_usart_sync_rev Revision History
+ * - v1.0.0 Initial Release
+ *
+ *@{
+ */
+
+#include <hpl_usart.h>
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+/**
+ * \brief USART descriptor device structure
+ */
+struct _usart_sync_device {
+	void *hw;
+};
+
+/**
+ * \name HPL functions
+ */
+//@{
+/**
+ * \brief Initialize synchronous USART
+ *
+ * This function does low level USART configuration.
+ *
+ * \param[in] device The pointer to USART device instance
+ * \param[in] hw The pointer to hardware instance
+ *
+ * \return Initialization status
+ */
+int32_t _usart_sync_init(struct _usart_sync_device *const device, void *const hw);
+
+/**
+ * \brief Deinitialize USART
+ *
+ * This function closes the given USART by disabling its clock.
+ *
+ * \param[in] device The pointer to USART device instance
+ */
+void _usart_sync_deinit(struct _usart_sync_device *const device);
+
+/**
+ * \brief Enable usart module
+ *
+ * This function will enable the usart module
+ *
+ * \param[in] device The pointer to USART device instance
+ */
+void _usart_sync_enable(struct _usart_sync_device *const device);
+
+/**
+ * \brief Disable usart module
+ *
+ * This function will disable the usart module
+ *
+ * \param[in] device The pointer to USART device instance
+ */
+void _usart_sync_disable(struct _usart_sync_device *const device);
+
+/**
+ * \brief Calculate baud rate register value
+ *
+ * \param[in] baud Required baud rate
+ * \param[in] clock_rate clock frequency
+ * \param[in] samples The number of samples
+ * \param[in] mode USART mode
+ * \param[in] fraction A fraction value
+ *
+ * \return Calculated baud rate register value
+ */
+uint16_t _usart_sync_calculate_baud_rate(const uint32_t baud, const uint32_t clock_rate, const uint8_t samples,
+                                         const enum usart_baud_rate_mode mode, const uint8_t fraction);
+
+/**
+ * \brief Set baud rate
+ *
+ * \param[in] device The pointer to USART device instance
+ * \param[in] baud_rate A baud rate to set
+ */
+void _usart_sync_set_baud_rate(struct _usart_sync_device *const device, const uint32_t baud_rate);
+
+/**
+ * \brief Set data order
+ *
+ * \param[in] device The pointer to USART device instance
+ * \param[in] order A data order to set
+ */
+void _usart_sync_set_data_order(struct _usart_sync_device *const device, const enum usart_data_order order);
+
+/**
+ * \brief Set mode
+ *
+ * \param[in] device The pointer to USART device instance
+ * \param[in] mode A mode to set
+ */
+void _usart_sync_set_mode(struct _usart_sync_device *const device, const enum usart_mode mode);
+
+/**
+ * \brief Set parity
+ *
+ * \param[in] device The pointer to USART device instance
+ * \param[in] parity A parity to set
+ */
+void _usart_sync_set_parity(struct _usart_sync_device *const device, const enum usart_parity parity);
+
+/**
+ * \brief Set stop bits mode
+ *
+ * \param[in] device The pointer to USART device instance
+ * \param[in] stop_bits A stop bits mode to set
+ */
+void _usart_sync_set_stop_bits(struct _usart_sync_device *const device, const enum usart_stop_bits stop_bits);
+
+/**
+ * \brief Set character size
+ *
+ * \param[in] device The pointer to USART device instance
+ * \param[in] size A character size to set
+ */
+void _usart_sync_set_character_size(struct _usart_sync_device *const device, const enum usart_character_size size);
+
+/**
+ * \brief Retrieve usart status
+ *
+ * \param[in] device The pointer to USART device instance
+ */
+uint32_t _usart_sync_get_status(const struct _usart_sync_device *const device);
+
+/**
+ * \brief Write a byte to the given USART instance
+ *
+ * \param[in] device The pointer to USART device instance
+ * \param[in] data Data to write
+ */
+void _usart_sync_write_byte(struct _usart_sync_device *const device, uint8_t data);
+
+/**
+ * \brief Read a byte from the given USART instance
+ *
+ * \param[in] device The pointer to USART device instance
+ * \param[in] data Data to write
+ *
+ * \return Data received via USART interface.
+ */
+uint8_t _usart_sync_read_byte(const struct _usart_sync_device *const device);
+
+/**
+ * \brief Check if USART is ready to send next byte
+ *
+ * \param[in] device The pointer to USART device instance
+ *
+ * \return Status of the ready check.
+ * \retval true if the USART is ready to send next byte
+ * \retval false if the USART is not ready to send next byte
+ */
+bool _usart_sync_is_byte_sent(const struct _usart_sync_device *const device);
+
+/**
+ * \brief Check if there is data received by USART
+ *
+ * \param[in] device The pointer to USART device instance
+ *
+ * \return Status of the data received check.
+ * \retval true if the USART has received a byte
+ * \retval false if the USART has not received a byte
+ */
+bool _usart_sync_is_byte_received(const struct _usart_sync_device *const device);
+
+/**
+ * \brief Set the state of flow control pins
+ *
+ * \param[in] device The pointer to USART device instance
+ * \param[in] state - A state of flow control pins to set
+ */
+void _usart_sync_set_flow_control_state(struct _usart_sync_device *const     device,
+                                        const union usart_flow_control_state state);
+
+/**
+ * \brief Retrieve the state of flow control pins
+ *
+ * This function retrieves the of flow control pins.
+ *
+ * \return USART_FLOW_CONTROL_STATE_UNAVAILABLE.
+ */
+union usart_flow_control_state _usart_sync_get_flow_control_state(const struct _usart_sync_device *const device);
+
+/**
+ * \brief Retrieve ordinal number of the given USART hardware instance
+ *
+ * \param[in] device The pointer to USART device instance
+ *
+ * \return The ordinal number of the given USART hardware instance
+ */
+uint8_t _usart_sync_get_hardware_index(const struct _usart_sync_device *const device);
+//@}
+
+#ifdef __cplusplus
+}
+#endif
+/**@}*/
+#endif /* _HPL_SYNC_USART_H_INCLUDED */
diff --git a/atmel-samd/asf4/samd21/hal/include/hpl_usb.h b/atmel-samd/asf4/samd21/hal/include/hpl_usb.h
new file mode 100644
index 000000000..d31bd9785
--- /dev/null
+++ b/atmel-samd/asf4/samd21/hal/include/hpl_usb.h
@@ -0,0 +1,281 @@
+/**
+ * \file
+ *
+ * \brief SAM USB HPL
+ *
+ * Copyright (C) 2015 Atmel Corporation. All rights reserved.
+ *
+ * \asf_license_start
+ *
+ * \page License
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright notice,
+ *    this list of conditions and the following disclaimer.
+ *
+ * 2. Redistributions in binary form must reproduce the above copyright notice,
+ *    this list of conditions and the following disclaimer in the documentation
+ *    and/or other materials provided with the distribution.
+ *
+ * 3. The name of Atmel may not be used to endorse or promote products derived
+ *    from this software without specific prior written permission.
+ *
+ * 4. This software may only be redistributed and used in connection with an
+ *    Atmel microcontroller product.
+ *
+ * THIS SOFTWARE IS PROVIDED BY ATMEL "AS IS" AND ANY EXPRESS OR IMPLIED
+ * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
+ * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT ARE
+ * EXPRESSLY AND SPECIFICALLY DISCLAIMED. IN NO EVENT SHALL ATMEL BE LIABLE FOR
+ * ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+ * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
+ * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
+ * ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+ * POSSIBILITY OF SUCH DAMAGE.
+ *
+ * \asf_license_stop
+ *
+ */
+
+#ifndef _HPL_USB_H_INCLUDED
+#define _HPL_USB_H_INCLUDED
+
+#include <compiler.h>
+#include <utils.h>
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+/** \name USB Spec definitions */
+/*@{*/
+
+/** Return 8-bit unsigned USB data. */
+#define USB_GET_U8(addr, offset) (((uint8_t *)(addr))[(offset)])
+
+/** Return 16-bit unsigned USB data. */
+#define USB_GET_U16(addr, offset) ((((uint8_t *)(addr))[(offset) + 0] << 0) + (((uint8_t *)(addr))[(offset) + 1] << 8))
+
+/** Return 32-bit unsigned USB data. */
+#define USB_GET_U32(addr, offset)                                                                                      \
+	((((uint8_t *)(addr))[(offset) + 0] << 0) + (((uint8_t *)(addr))[(offset) + 1] << 8)                               \
+	 + (((uint8_t *)(addr))[(offset) + 2] << 16)                                                                       \
+	 + (((uint8_t *)(addr))[(offset) + 3] << 32))
+
+/** Offset of bmRequestType in USB request buffer. */
+#define USB_bmRequestType_Offset 0
+
+/** Offset of bRequest in USB request buffer. */
+#define USB_bRequest_Offset 1
+
+/** Offset of wValue in USB request buffer. */
+#define USB_wValue_Offset 2
+
+/** Offset of wIndex in USB request buffer. */
+#define USB_wIndex_Offset 4
+
+/** Offset of wLength in USB request buffer. */
+#define USB_wLength_Offset 6
+
+/** Get value of bmRequestType from USB request. */
+#define USB_GET_bmRequestType(req) USB_GET_U8((req), USB_bmRequestType_Offset)
+
+/** Get value of bRequest from USB request. */
+#define USB_GET_bRequest(req) USB_GET_U8((req), USB_bRequest_Offset)
+
+/** Get value of wValue from USB request. */
+#define USB_GET_wValue(req) USB_GET_U16((req), USB_wValue_Offset)
+
+/** Get value of wIndex from USB request. */
+#define USB_GET_wIndex(req) USB_GET_U16((req), USB_wIndex_Offset)
+
+/** Get value of wLength from USB request. */
+#define USB_GET_wLength(req) USB_GET_U16((req), USB_wLength_Offset)
+
+/** USB request IN indication of bmRequestType. */
+#define USB_REQ_TYPE_IN 0x80u
+
+/** USB endpoint number mask of bEndpointAddress. */
+#define USB_EP_N_MASK 0x0Fu
+
+/** USB endpoint direction bit of bEndpointAddress. */
+#define USB_EP_DIR 0x80u
+
+/** Get USB endpoint direction from endpoint address. */
+#define USB_EP_GET_DIR(ep_addr) ((ep_addr)&USB_EP_DIR)
+
+/** Get USB endpoint number from endpoint address. */
+#define USB_EP_GET_N(ep_addr) ((ep_addr)&USB_EP_N_MASK)
+
+/** Transfer type in EP descriptor bmAttributes: Control. */
+#define USB_EP_XTYPE_CTRL 0x0
+
+/** Transfer type in EP descriptor bmAttributes: Isochronous. */
+#define USB_EP_XTYPE_ISOCH 0x1
+
+/** Transfer type in EP descriptor bmAttributes: Bulk. */
+#define USB_EP_XTYPE_BULK 0x2
+
+/** Transfer type in EP descriptor bmAttributes: Interrupt. */
+#define USB_EP_XTYPE_INTERRUPT 0x3
+
+/** Transfer type mask in EP descriptor bmAttributes. */
+#define USB_EP_XTYPE_MASK 0x3u
+
+/*@}*/
+
+/** \name USB status codes
+ *@{
+ */
+/** USB operation is done successfully. */
+#define USB_OK 0
+/** USB (endpoint) is busy. */
+#define USB_BUSY 1
+/** USB (endpoint) is halted. */
+#define USB_HALTED 2
+
+/** General error. */
+#define USB_ERROR 0x10
+/** Operation is denied by hardware (e.g., syncing). */
+#define USB_ERR_DENIED 0x11
+/** Input parameter error. */
+#define USB_ERR_PARAM 0x12
+/** Functionality is not supported (e.g., initialize endpoint without cache to be control). */
+#define USB_ERR_FUNC 0x13
+/** Re-initialize, re-enable ... */
+#define USB_ERR_REDO 0x14
+/** Not enough resource (memory, endpoints ...). */
+#define USB_ERR_ALLOC_FAIL 0x15
+/*@}*/
+
+/** USB speed. */
+enum usb_speed {
+	/** USB Low Speed. */
+	USB_SPEED_LS,
+	/** USB Full Speed. */
+	USB_SPEED_FS,
+	/** USB High Speed. */
+	USB_SPEED_HS,
+	/** USB Super Speed. */
+	USB_SPEED_SS
+};
+
+/** USB transaction type. */
+enum usb_trans_type {
+	/** USB SETUP transaction. */
+	USB_TRANS_SETUP,
+	/** USB IN transaction. */
+	USB_TRANS_IN,
+	/** USB OUT transaction. */
+	USB_TRANS_OUT
+};
+
+/** USB events that generates the device callbacks. */
+enum usb_event {
+	/** USB VBus changed, with parameter as present/not present. */
+	USB_EV_VBUS,
+	/** USB RESET detected on bus. */
+	USB_EV_RESET,
+	/** USB wakeup. */
+	USB_EV_WAKEUP,
+	/** USB LPM suspend, with parameter as \ref usb_lpm_attributes. */
+	USB_EV_LPM_SUSPEND,
+	/** USB suspend. */
+	USB_EV_SUSPEND,
+	/** USB error, with parameter as error code. */
+	USB_EV_ERROR,
+	/** Number of USB event types. */
+	USB_EV_N
+};
+
+/** Control action for USB device endpoint stall. */
+enum usb_ep_stall_ctrl {
+	/** Clear stall of the endpoint. */
+	USB_EP_STALL_CLR,
+	/** Stall the endpoint. */
+	USB_EP_STALL_SET,
+	/** Return the stall status. */
+	USB_EP_STALL_GET
+};
+
+/** Control action for USB device endpoint halt. */
+enum usb_ep_halt_ctrl {
+	/** Clear halt of the endpoint. */
+	USB_EP_HALT_CLR = USB_EP_STALL_CLR,
+	/** Stall the endpoint. */
+	USB_EP_HALT_SET = USB_EP_STALL_SET,
+	/** Return the halt status. */
+	USB_EP_HALT_GET = USB_EP_STALL_GET
+};
+
+/** USB transactions status codes. */
+enum usb_trans_code {
+	/** TX or RX has been done without error. */
+	USB_TRANS_DONE,
+	/** The endpoint is stalled. */
+	USB_TRANS_STALL,
+	/** The endpoint transactions are aborted (cancel, control setup/status). */
+	USB_TRANS_ABORT,
+	/** The endpoint transactions are aborted by reset/disable. */
+	USB_TRANS_RESET,
+	/** Error is reported on the endpoint. */
+	USB_TRANS_ERROR
+};
+
+/** Transfer status codes. */
+enum usb_xfer_code {
+	/** Transfer is done without error, for ctrl it means status packet done. */
+	USB_XFER_DONE,
+	/** For control transfer only, data stage is done without error. */
+	USB_XFER_DATA,
+	/** Endpoint stall is set. */
+	USB_XFER_HALT,
+	/** Endpoint stall is cleared. */
+	USB_XFER_UNHALT,
+	/** Transfer is aborted. */
+	USB_XFER_ABORT,
+	/** Transfer is aborted because endpoint reset/disable. */
+	USB_XFER_RESET,
+	/** There was an error. */
+	USB_XFER_ERROR
+};
+
+/** USB endpoint errors. */
+enum usb_ep_error {
+	/** No error. */
+	USB_EP_NO_ERROR,
+	/** CRC error. */
+	USB_EP_ERR_CRC,
+	/** Endpoint transfer overflow. */
+	USB_EP_ERR_OVERFLOW,
+	/** Other endpoint errors. */
+	USB_EP_ERR_GENERAL
+};
+
+/** Endpoint transfer state. */
+enum usb_ep_state {
+	/** Endpoint is disabled. */
+	USB_EP_S_DISABLED,
+	/** Endpoint is not busy. */
+	USB_EP_S_IDLE,
+	/** Control transfer only, endpoint is transferring setup packet. */
+	USB_EP_S_X_SETUP,
+	/** Endpoint is transferring data. */
+	USB_EP_S_X_DATA,
+	/** Control transfer only, endpoint is in status stage. */
+	USB_EP_S_X_STATUS,
+	/** Endpoint is halted. */
+	USB_EP_S_HALTED,
+	/** Endpoint error. */
+	USB_EP_S_ERROR
+};
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif /* _HPL_USB_H_INCLUDED */
diff --git a/atmel-samd/asf4/samd21/hal/include/hpl_usb_device.h b/atmel-samd/asf4/samd21/hal/include/hpl_usb_device.h
new file mode 100644
index 000000000..640833f45
--- /dev/null
+++ b/atmel-samd/asf4/samd21/hal/include/hpl_usb_device.h
@@ -0,0 +1,387 @@
+/**
+ * \file
+ *
+ * \brief SAM USB HPL
+ *
+ * Copyright (C) 2016 Atmel Corporation. All rights reserved.
+ *
+ * \asf_license_start
+ *
+ * \page License
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright notice,
+ *    this list of conditions and the following disclaimer.
+ *
+ * 2. Redistributions in binary form must reproduce the above copyright notice,
+ *    this list of conditions and the following disclaimer in the documentation
+ *    and/or other materials provided with the distribution.
+ *
+ * 3. The name of Atmel may not be used to endorse or promote products derived
+ *    from this software without specific prior written permission.
+ *
+ * 4. This software may only be redistributed and used in connection with an
+ *    Atmel microcontroller product.
+ *
+ * THIS SOFTWARE IS PROVIDED BY ATMEL "AS IS" AND ANY EXPRESS OR IMPLIED
+ * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
+ * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT ARE
+ * EXPRESSLY AND SPECIFICALLY DISCLAIMED. IN NO EVENT SHALL ATMEL BE LIABLE FOR
+ * ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+ * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
+ * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
+ * ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+ * POSSIBILITY OF SUCH DAMAGE.
+ *
+ * \asf_license_stop
+ *
+ */
+
+#ifndef _HPL_USB_DEVICE_H_INCLUDED
+#define _HPL_USB_DEVICE_H_INCLUDED
+
+#include <hpl_usb.h>
+#include "hpl_usb_config.h"
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+/** USB Device callback type. */
+enum usb_d_cb_type {
+	/** USB device SOF callback. */
+	USB_D_CB_SOF,
+	/** USB device events callbacks. */
+	USB_D_CB_EVENT,
+	/** Number of types of USB device callback types. */
+	USB_D_CB_N
+};
+
+/** USB Device endpoint callback type. */
+enum usb_d_ep_cb_type {
+	/** USB device endpoint setup callback. */
+	USB_D_EP_CB_SETUP,
+	/** USB device endpoint more data callback. */
+	USB_D_EP_CB_MORE,
+	/** USB device endpoint transaction done or error callback. */
+	USB_D_EP_CB_XFER,
+	/** Number of types of USB device endpoint callback types. */
+	USB_D_EP_CB_N
+};
+
+/** Control action for USB device LPM handshake. */
+enum usb_d_lpm_ctrl {
+	/** No LPM handshake, not supported. */
+	USB_D_LPM_DISABLE,
+	/** ACK the LPM transaction. */
+	USB_D_LPM_ACK,
+	/** NYET the LPM transaction. */
+	USB_D_LPM_NYET
+};
+
+/**
+ *  USB device transfer descriptor.
+ */
+struct usb_d_transfer {
+	/** Pointer to data buffer to transfer.
+	 *  Note that it's recommended that the buffer is 32-bit aligned since
+	 *  some of USB peripheral require this.
+	 */
+	uint8_t *buf;
+	/** Transfer size, in number of bytes.
+	 *  Note that it's recommended that the buffer size is 32-bit aligned
+	 *  (modeled by 4) since some of USB peripheral require this.
+	 */
+	uint32_t size;
+	/** Endpoint address. */
+	uint8_t ep;
+	/** Append ZLP for IN transfer, wait ZLP for OUT transfer. */
+	uint8_t zlp;
+};
+
+/** USB device transactions status structure. */
+struct usb_d_trans_status {
+	/** Total data size. */
+	uint32_t size;
+	/** Total transfered data count. */
+	uint32_t count;
+	/** Endpoint address. */
+	uint8_t ep;
+	/** Endpoint type - CTRL/ISO/INT/BULK. */
+	uint8_t xtype : 2;
+	/** Transactions state, busy or not. */
+	uint8_t busy : 1;
+	/** Transactions state, setup received or not. */
+	uint8_t setup : 1;
+	/** Transactions state, stall or not. */
+	uint8_t stall : 1;
+	/** Transactions direction. */
+	uint8_t dir : 1;
+};
+
+/** Prototype function for callback that is invoked on USB device SOF. */
+typedef void (*_usb_d_dev_sof_cb_t)(void);
+
+/** Prototype function for callback that is invoked on USB device events. */
+typedef void (*_usb_d_dev_event_cb_t)(const enum usb_event, const uint32_t param);
+
+/** HPL USB device callbacks. */
+struct _usb_d_dev_callbacks {
+	/** Callback that is invoked on SOF. */
+	_usb_d_dev_sof_cb_t sof;
+	/** Callback that is invoked on USB RESET/WAKEUP/RESUME/SUSPEND. */
+	_usb_d_dev_event_cb_t event;
+};
+
+/** USB device endpoint callbacks. */
+enum usb_d_dev_ep_cb_type {
+	/** Setup packet is received. */
+	USB_D_DEV_EP_CB_SETUP,
+	/** Try to require more data. */
+	USB_D_DEV_EP_CB_MORE,
+	/** Transaction done OK/ERROR. */
+	USB_D_DEV_EP_CB_DONE,
+	/** Number of device endpoint callbacks. */
+	USB_D_DEV_EP_CB_N
+};
+
+/**
+ *  Callback that is invoked when control SETUP packet has bee received.
+ *  \ref _usb_d_dev_ep_read_req() must be invoked to read setup data, and allow
+ *  IN/OUT transactions on control endpoint.
+ */
+typedef void (*_usb_d_dev_ep_cb_setup_t)(const uint8_t ep);
+
+/** Callback that is invoked when buffer is done, but last packet is full size
+ *  packet without ZLP. Return \c true if more data has been requested. */
+typedef bool (*_usb_d_dev_ep_cb_more_t)(const uint8_t ep, const uint32_t transfered);
+
+/** Callback that is invoked when all data is finished, including background
+ *  transfer, or error happens. */
+typedef void (*_usb_d_dev_ep_cb_done_t)(const uint8_t ep, const int32_t code, const uint32_t transfered);
+
+/** Callbacks for HPL USB device endpoint. */
+struct _usb_d_dev_ep_callbacks {
+	/** Callback that is invoked when SETUP packet is received.
+	 *  \ref _usb_d_dev_ep_read_req() must be invoked to read setup data, and
+	 *  allow IN/OUT transactions on control endpoint.
+	 */
+	_usb_d_dev_ep_cb_setup_t setup;
+	/** Callback that is invoked to check if buffer is NULL and more data is
+	 *  required.
+	 *  It's called when last packet is full size packet, without
+	 *  auto ZLP enabled.
+	 *  It could be called when background transfer is still in progress.
+	 */
+	_usb_d_dev_ep_cb_more_t more;
+	/** Callback that is invoked when transaction is done, including background
+	 *  transfer, or error occurs.
+	 */
+	_usb_d_dev_ep_cb_done_t done;
+};
+
+/**
+ * \brief Initialize the USB device instance
+ * \return Operation result status.
+ * \retval 0 Success.
+ * \retval <0 Error code.
+ */
+int32_t _usb_d_dev_init(void);
+
+/**
+ * \brief Deinitialize the USB device instance
+ * \return Operation result status.
+ * \retval 0 Success.
+ * \retval <0 Error code.
+ */
+void _usb_d_dev_deinit(void);
+
+/**
+ * \brief Register callback to handle USB device events
+ * \param[in] type Callback type. See \ref usb_d_cb_type.
+ * \param[in] func Pointer to callback function.
+ *         Refer to \ref _usb_d_dev_callbacks for the prototypes.
+ */
+void _usb_d_dev_register_callback(const enum usb_d_cb_type type, const FUNC_PTR func);
+
+/**
+ * \brief Register callback to handle USB device endpoint events
+ * \param[in] type Callback type. See \ref usb_d_dev_ep_cb_type.
+ * \param[in] func Pointer to callback function.
+ *         Refer to \ref _usb_d_dev_ep_callbacks for the prototypes.
+ */
+void _usb_d_dev_register_ep_callback(const enum usb_d_dev_ep_cb_type type, const FUNC_PTR func);
+
+/**
+ * \brief Enable the USB device
+ * \return Operation result status.
+ * \retval 0 Success.
+ * \retval <0 Error code.
+ */
+int32_t _usb_d_dev_enable(void);
+
+/**
+ * \brief Disable the USB device
+ * \return Operation result status.
+ * \retval 0 Success.
+ * \retval <0 Error code.
+ */
+int32_t _usb_d_dev_disable(void);
+
+/**
+ * \brief Attach the USB device
+ */
+void _usb_d_dev_attach(void);
+
+/**
+ * \brief Detach the USB device
+ */
+void _usb_d_dev_detach(void);
+
+/**
+ * \brief Send the USB device remote wakeup to host
+ */
+void _usb_d_dev_send_remotewakeup(void);
+
+/**
+ * \brief Get the USB device working speed
+ * \return USB speed. See \ref usb_speed.
+ */
+enum usb_speed _usb_d_dev_get_speed(void);
+
+/**
+ * \brief Set the USB device address
+ * \param[in] addr Address to be used.
+ */
+void _usb_d_dev_set_address(const uint8_t addr);
+
+/**
+ * \brief Get the USB device address
+ * \return Address that is used.
+ */
+uint8_t _usb_d_dev_get_address(void);
+
+/**
+ * \brief Get the USB device frame number
+ * \return The frame number.
+ */
+uint16_t _usb_d_dev_get_frame_n(void);
+
+/**
+ * \brief Get the USB device micro frame number
+ * \return The micro frame number inside one frame (0~7).
+ */
+uint8_t _usb_d_dev_get_uframe_n(void);
+
+/**
+ * \brief Initialize and enable the USB device default endpoint 0
+ * \param[in] max_pkt_siz Max endpoint size.
+ * \return Operation result status.
+ * \retval 0 Success.
+ * \retval <0 Error code.
+ */
+int32_t _usb_d_dev_ep0_init(const uint8_t max_pkt_siz);
+
+/**
+ * \brief Initialize and enable the USB device endpoint
+ * \param[in] ep Endpoint address,
+ *               see endpoint descriptor details in USB spec.
+ * \param[in] attr Endpoint attributes,
+ *                 see endpoint descriptor details in USB spec.
+ * \param[in] max_pkt_siz Endpoint size,
+ *                        see endpoint descriptor details in USB spec.
+ * \return Operation result status.
+ * \retval 0 Success.
+ * \retval <0 Error code.
+ */
+int32_t _usb_d_dev_ep_init(const uint8_t ep, const uint8_t attr, uint16_t max_pkt_siz);
+
+/**
+ * \brief Disable and deinitialize the USB device endpoint
+
+ * \param[in] ep The endpoint to deinitialize.
+ */
+void _usb_d_dev_ep_deinit(const uint8_t ep);
+
+/**
+ * \brief Enable the endpoint
+ * \param[in] ep The endpoint to enable.
+ * \return Operation result status.
+ * \retval 0 Success.
+ * \retval <0 Error code.
+ */
+int32_t _usb_d_dev_ep_enable(const uint8_t ep);
+
+/**
+ * \brief Disable the endpoint
+ * \param[in] ep The endpoint to disable.
+ */
+void _usb_d_dev_ep_disable(const uint8_t ep);
+
+/**
+ * \brief Set/Clear/Get USB device endpoint stall status
+ * \param[in] ep Endpoint address.
+ * \param[in] ctrl Operation selector. See \ref usb_ep_stall_ctrl.
+ * \return Operation result or stall status.
+ * \retval 0 Success or not stall.
+ * \retval 1 Endpoint is stalled.
+ * \retval -1 error.
+ */
+int32_t _usb_d_dev_ep_stall(const uint8_t ep, const enum usb_ep_stall_ctrl ctrl);
+
+/**
+ * \brief Read setup request data from specific endpoint
+ * \param[in] ep Endpoint address.
+ * \param[out] req_buf Pointer to buffer to locate the setup packet.
+ * \return Number of bytes or error code.
+ * \retval <0 error code.
+ * \retval 0 No setup packet ready for read.
+ * \retval >0 Size of bytes read, and ready to start IN/OUT. Note that if
+ *         this number is over 8, only first 8 bytes will be copied.
+ */
+int32_t _usb_d_dev_ep_read_req(const uint8_t ep, uint8_t *req_buf);
+
+/**
+ * \brief Start USB device transfer
+ *
+ * On different USB peripheral hardware the transaction buffer address and size
+ * may have different constraints. E.g., some hardware may require input address
+ * 32-bit aligned, and input size 32-bit aligned. Refer to the corresponding
+ * hardware usage reference documents.
+ * The constraints are checked in implementation, with error code returned.
+ *
+ * \param[in] trans Pointer to the transaction description.
+ * \return Operation result status.
+ * \retval 1 Busy.
+ * \retval 0 Success.
+ * \retval <0 Error code.
+ */
+int32_t _usb_d_dev_ep_trans(const struct usb_d_transfer *trans);
+
+/**
+ * \brief Abort pending USB device transaction on specific endpoint
+ * \param[in] ep Endpoint address to abort.
+ */
+void _usb_d_dev_ep_abort(const uint8_t ep);
+
+/**
+ * \brief Retrieve endpoint status.
+ * \param[in] ep Endpoint address.
+ * \param[out] stat Pointer to buffer to fill status description.
+ * \return Status.
+ * \retval 2 Packet writing.
+ * \retval 1 Busy.
+ * \retval 0 Ready.
+ * \retval <0 Error code.
+ */
+int32_t _usb_d_dev_ep_get_status(const uint8_t ep, struct usb_d_trans_status *stat);
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif /* _HPL_USB_DEVICE_H_INCLUDED */
diff --git a/atmel-samd/asf4/samd21/hal/include/hpl_usb_host.h b/atmel-samd/asf4/samd21/hal/include/hpl_usb_host.h
new file mode 100644
index 000000000..ee48ecc3a
--- /dev/null
+++ b/atmel-samd/asf4/samd21/hal/include/hpl_usb_host.h
@@ -0,0 +1,628 @@
+/**
+ * \file
+ *
+ * \brief SAM USB host HPL
+ *
+ * Copyright (C) 2016 - 2017 Atmel Corporation. All rights reserved.
+ *
+ * \asf_license_start
+ *
+ * \page License
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright notice,
+ *    this list of conditions and the following disclaimer.
+ *
+ * 2. Redistributions in binary form must reproduce the above copyright notice,
+ *    this list of conditions and the following disclaimer in the documentation
+ *    and/or other materials provided with the distribution.
+ *
+ * 3. The name of Atmel may not be used to endorse or promote products derived
+ *    from this software without specific prior written permission.
+ *
+ * 4. This software may only be redistributed and used in connection with an
+ *    Atmel microcontroller product.
+ *
+ * THIS SOFTWARE IS PROVIDED BY ATMEL "AS IS" AND ANY EXPRESS OR IMPLIED
+ * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
+ * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT ARE
+ * EXPRESSLY AND SPECIFICALLY DISCLAIMED. IN NO EVENT SHALL ATMEL BE LIABLE FOR
+ * ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+ * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
+ * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
+ * ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+ * POSSIBILITY OF SUCH DAMAGE.
+ *
+ * \asf_license_stop
+ *
+ */
+
+#ifndef _HPL_USB_HOST_H_INCLUDED
+#define _HPL_USB_HOST_H_INCLUDED
+
+#include <hpl_usb.h>
+#include <hpl_irq.h>
+#include "hpl_usb_config.h"
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+/** Driver version */
+#define USB_H_VERSION 0x00000001
+
+/**
+ * @brief      USB HCD callback types
+ */
+enum usb_h_cb_type {
+	/** SOF generated */
+	USB_H_CB_SOF,
+	/** Root Hub change detected */
+	USB_H_CB_ROOTHUB_CHANGE,
+	/** Number of USB HCD callback types */
+	USB_H_CB_N
+};
+
+/**
+ * @brief      USB HCD resource strategy
+ */
+enum usb_h_rsc_strategy {
+	/** Normal resource allocation, e.g.,
+     *  1 bank for interrupt endpoint,
+     *  2 bank for bulk endpoint and normal iso endpoint,
+     *  3 bank for iso high bandwidth endpoint.
+     */
+	USB_H_RSC_NORMAL = false,
+	/** Minimal resource allocation, e.g., only 1 bank for bulk endpoints */
+	USB_H_RSC_MINIMAL = true
+};
+
+/**
+ * @brief      USB HCD pipe states
+ */
+enum usb_h_pipe_state {
+	/** Pipe is free to allocate */
+	USB_H_PIPE_S_FREE = 0x00,
+	/** Pipe is in configuration */
+	USB_H_PIPE_S_CFG = 0x01,
+	/** Pipe is allocated and idle */
+	USB_H_PIPE_S_IDLE = 0x02,
+	/** Pipe in control setup stage */
+	USB_H_PIPE_S_SETUP = 0x03,
+	/** Pipe in data IN stage */
+	USB_H_PIPE_S_DATI = 0x05,
+	/** Pipe in data OUT stage */
+	USB_H_PIPE_S_DATO = 0x06,
+	/** Pipe in data IN ZLP stage */
+	USB_H_PIPE_S_ZLPI = 0x07,
+	/** Pipe in data OUT ZLP stage */
+	USB_H_PIPE_S_ZLPO = 0x08,
+	/** Pipe in control status IN stage */
+	USB_H_PIPE_S_STATI = 0x09,
+	/** Pipe in control status OUT stage */
+	USB_H_PIPE_S_STATO = 0x0A,
+	/** Taken by physical pipe (in process) */
+	USB_H_PIPE_S_TAKEN = 0x10
+};
+
+/**
+ * @brief      USB HCD status code
+ */
+enum usb_h_status {
+	/** OK */
+	USB_H_OK = ERR_NONE,
+	/** Busy */
+	USB_H_BUSY = ERR_BUSY,
+	/** Denied */
+	USB_H_DENIED = ERR_DENIED,
+	/** Timeout */
+	USB_H_TIMEOUT = ERR_TIMEOUT,
+	/** Abort */
+	USB_H_ABORT = ERR_ABORTED,
+	/** Stall protocol */
+	USB_H_STALL = ERR_PROTOCOL,
+	/** Transfer reset by pipe re-configure */
+	USB_H_RESET = ERR_REQ_FLUSHED,
+	/** Argument error */
+	USB_H_ERR_ARG = ERR_INVALID_ARG,
+	/** Operation not supported */
+	USB_H_ERR_UNSP_OP = ERR_UNSUPPORTED_OP,
+	/** No resource */
+	USB_H_ERR_NO_RSC = ERR_NO_RESOURCE,
+	/** Not initialized */
+	USB_H_ERR_NOT_INIT = ERR_NOT_INITIALIZED,
+	/** Some general error */
+	USB_H_ERR = ERR_IO
+};
+
+/** Forward declare for pipe structure */
+struct usb_h_pipe;
+
+/** Forward declare for driver descriptor structure */
+struct usb_h_desc;
+
+/**
+ * \brief Prototyping USB HCD callback of SOF
+ */
+typedef void (*usb_h_cb_sof_t)(struct usb_h_desc *drv);
+
+/**
+ * \brief Prototyping USB HCD callback of root hub changing.
+ * According to the bitmap size, max port number is 31.
+ */
+typedef void (*usb_h_cb_roothub_t)(struct usb_h_desc *drv, uint8_t port, uint8_t ftr);
+
+/**
+ * Prototyping USB HCD callback of pipe transfer done.
+ * For control pipe, it's forced to call even if there is no transfer
+ * in progress, since the pipe size could be changed at run time.
+ */
+typedef void (*usb_h_pipe_cb_xfer_t)(struct usb_h_pipe *pipe);
+
+/** Access to max packet size of a pipe */
+#define usb_h_pipe_max_pkt_size(p) (p->max_pkt_size)
+
+/** Access to device address of a pipe */
+#define usb_h_pipe_dev_addr(p) (p->dev)
+
+/** Access to endpoint address of a pipe */
+#define usb_h_pipe_ep_addr(p) (p->ep)
+
+/** Access to state of a pipe */
+#define usb_h_pipe_state(p) (p->x.general.state)
+
+/** Access to status of a pipe */
+#define usb_h_pipe_status(p) (p->x.general.status)
+
+/**
+ * @brief      USB Host Controller device structure
+ */
+struct usb_h_desc {
+	/** Pointer to hardware base */
+	void *hw;
+	/** Pointer to private data for Host Controller driver */
+	void *prvt;
+	/** Interrupt handling descriptor */
+	struct _irq_descriptor irq;
+	/** Callback of SOF */
+	usb_h_cb_sof_t sof_cb;
+	/** Callback of root hub change */
+	usb_h_cb_roothub_t rh_cb;
+#if CONF_USB_H_INST_OWNER_SP
+	/** Extension for the driver owner (upper layer user) */
+	void *owner;
+#endif
+};
+
+/**
+ * @brief      Transfer descriptor for control transfer
+ *
+ * Timing in USB 2.0 spec.:
+ * - 9.2.6.1 : USB sets an upper limit of 5 seconds as the upper limit for any
+ *             command to be processed.
+ * - 9.2.6.3 : if a device receives a SetAddress() request, the device must be
+ *             able to complete processing of the request and be able to
+ *             successfully complete the Status stage of the request within
+ *             50 ms.
+ *             After successful completion of the Status stage, the device is
+ *             allowed a SetAddress() recovery interval of 2 ms. At the end of
+ *             this interval, the device must be able to accept Setup packets
+ *             addressed to the new address.
+ * - 9.2.6.4 : For standard device requests that require no Data stage, a device
+ *             must be able to complete the request and be able to successfully
+ *             complete the Status stage of the request within 50 ms of receipt
+ *             of the request. This limitation applies to requests to the
+ *             device, interface, or endpoint.
+ *             For standard device requests that require data stage transfer to
+ *             the host, the device must be able to return the first data packet
+ *             to the host within 500 ms of receipt of the request. For
+ *             subsequent data packets, if any, the device must be able to
+ *             return them within 500 ms of successful completion of the
+ *             transmission of the previous packet. The device must then be
+ *             able to successfully complete the status stage within 50 ms after
+ *             returning the last data packet.
+ *             For standard device requests that require a data stage transfer
+ *             to the device, the 5-second limit applies.
+ * - 9.2.6.5 : Unless specifically exempted in the class document, all
+ *             class-specific requests must meet the timing limitations for
+ *             standard device requests.
+ *
+ * Conclusion:
+ * 1. Whole request with data: 5 seconds
+ * 2. Whole request without data: 50 ms
+ * 3. Data packets: 500 ms
+ */
+struct usb_h_ctrl_xfer {
+	/** Pointer to transfer data */
+	uint8_t *data;
+	/** Pointer to setup packet */
+	uint8_t *setup;
+	/** Expected transfer size */
+	uint16_t size;
+	/** Transfer count */
+	uint16_t count;
+	/** Timeout for request, -1 if disable timeout */
+	int16_t req_timeout;
+	/** Timeout between packets
+	 *  (500ms for data and 50ms for status), -1 if disabled */
+	int16_t pkt_timeout;
+	/** Packet size during transfer (<= allocate max packet size) */
+	uint16_t pkt_size;
+
+	/** Transfer state */
+	uint8_t state;
+	/** Last transfer status */
+	int8_t status;
+};
+
+/**
+ * @brief      Transfer descriptor for bulk / interrupt / iso transfer
+ */
+struct usb_h_bulk_int_iso_xfer {
+	/** Expected transfer size */
+	uint32_t size;
+	/** Transfer count */
+	uint32_t count;
+	/** Pointer to transfer data */
+	uint8_t *data;
+	/** Reserved */
+	uint16_t reserved[3];
+
+	/** Transfer state */
+	uint8_t state;
+	/** Last transfer status */
+	int8_t status;
+};
+
+/**
+ * @brief      Transfer descriptor for periodic high bandwidth transfer
+ */
+struct usb_h_high_bw_xfer {
+	/** Expected transfer size */
+	uint32_t size;
+	/** Transfer count */
+	uint32_t count;
+	/** Pointer to transfer data */
+	uint8_t *data;
+	/** Micro frame packet sizes */
+	uint16_t pkt_size[3];
+
+	/** Transfer state */
+	uint8_t state;
+	/** Last transfer status */
+	int8_t status;
+};
+
+/**
+ * @brief General transfer descriptor
+ */
+struct usb_h_xfer {
+	/** Reserved for different transfer */
+	union {
+		uint16_t u16[9];
+		uint8_t  u8[18];
+	} reserved;
+	/** Transfer state */
+	uint8_t state;
+	/** Last transfer status */
+	int8_t status;
+};
+
+/**
+ * @brief      USB Host Controller Driver Pipe structure
+ */
+struct usb_h_pipe {
+	/** Pointer to the USB Host Controller Driver */
+	struct usb_h_desc *hcd;
+	/** Pointer to the callback for transfer done */
+	usb_h_pipe_cb_xfer_t done;
+#if CONF_USB_H_INST_OWNER_SP
+	/** Pointer to the pipe owner */
+	void *owner;
+#endif
+
+	/** Endpoint max packet size (bits 10..0) */
+	uint16_t max_pkt_size;
+	/** Device address */
+	uint8_t dev;
+	/** Endpoint address */
+	uint8_t ep;
+
+	/** Endpoint interval */
+	uint8_t interval;
+	/** Endpoint type: Control, Isochronous, Bulk or Interrupt */
+	uint8_t type;
+	/** Current toggle (driver dependent) */
+	uint8_t toggle;
+	/** Endpoint number of banks (HW dependent) */
+	uint8_t bank : 2;
+	/** Transfer speed (HW dependent) */
+	uint8_t speed : 2;
+	/** High bandwidth periodic out */
+	uint8_t high_bw_out : 1;
+	/** Uses DMA (on transfer) */
+	uint8_t dma : 1;
+	/** Transfer ZLP support */
+	uint8_t zlp : 1;
+	/** Transfer periodic */
+	uint8_t periodic_start : 1;
+
+	/** Transfer status */
+	union {
+		/** General transfer info */
+		struct usb_h_xfer general;
+		/** Control transfer status */
+		struct usb_h_ctrl_xfer ctrl;
+		/** Bulk interrupt iso transfer status */
+		struct usb_h_bulk_int_iso_xfer bii;
+		/** Periodic high bandwidth transfer status */
+		struct usb_h_high_bw_xfer hbw;
+	} x;
+};
+
+/**
+ * @brief      USB HCD Initialization
+ *
+ * @param      drv     Pointer to the HCD driver instance
+ * @param[in]  hw      Pointer to hardware base
+ * @param[in]  prvt    The private driver data (implement specific)
+ *
+ * @return     Operation result status
+ * @retval     ERR_DENIED Hardware has been enabled
+ * @retval     ERR_NONE Operation done successfully
+ */
+int32_t _usb_h_init(struct usb_h_desc *drv, void *hw, void *prvt);
+
+/**
+ * @brief      USB HCD de-initialization
+ *
+ * @param      drv   The driver
+ */
+void _usb_h_deinit(struct usb_h_desc *drv);
+
+/**
+ * @brief      USB HCD enable
+ *
+ * @param      drv   The driver
+ */
+void _usb_h_enable(struct usb_h_desc *drv);
+
+/**
+ * @brief      USB HCD disable
+ *
+ * @param      drv   The driver
+ */
+void _usb_h_disable(struct usb_h_desc *drv);
+
+/**
+ * @brief      Register callbacks for USB HCD
+ *
+ * @param      drv   The driver
+ * @param[in]  type  The callback type
+ * @param[in]  cb    The callback function entry
+ *
+ * @return     Operation result status
+ * @retval     ERR_INVALID_ARG Argument error
+ * @retval     ERR_NONE Operation done successfully
+ */
+int32_t _usb_h_register_callback(struct usb_h_desc *drv, enum usb_h_cb_type type, FUNC_PTR cb);
+
+/**
+ * @brief      Return current frame number
+ *
+ * @param      drv   The driver
+ *
+ * @return     current frame number
+ */
+uint16_t _usb_h_get_frame_n(struct usb_h_desc *drv);
+
+/**
+ * @brief      Return current micro frame number
+ *
+ * @param      drv   The driver
+ *
+ * @return     current micro frame number
+ */
+uint8_t _usb_h_get_microframe_n(struct usb_h_desc *drv);
+
+/**
+ * @brief Suspend the USB bus
+ *
+ * @param drv The driver
+ */
+void _usb_h_suspend(struct usb_h_desc *drv);
+
+/**
+ * @brief Resume the USB bus
+ *
+ * @param drv The driver
+ */
+void _usb_h_resume(struct usb_h_desc *drv);
+
+/* Root hub related APIs */
+
+/**
+ * \brief Reset the root hub port
+ *
+ * \param[in,out] drv  Pointer to the USB HCD driver
+ * \param[in]     port Root hub port, ignored if there is only one port
+ */
+void _usb_h_rh_reset(struct usb_h_desc *drv, uint8_t port);
+
+/**
+ * \brief Suspend the root hub port
+ *
+ * \param[in,out] drv  Pointer to the USB HCD driver
+ * \param[in]     port Root hub port, ignored if there is only one port
+ */
+void _usb_h_rh_suspend(struct usb_h_desc *drv, uint8_t port);
+
+/**
+ * \brief Resume the root hub port
+ *
+ * \param[in,out] drv  Pointer to the USB HCD driver
+ * \param[in]     port Root hub port, ignored if there is only one port
+ */
+void _usb_h_rh_resume(struct usb_h_desc *drv, uint8_t port);
+
+/**
+ * \brief Root hub or port feature status check
+ *
+ * Check USB Spec. for hub status and feature selectors.
+ *
+ * \param[in] drv  Pointer to the USB HCD driver
+ * \param[in] port Set to 0 to get hub status, otherwise to get port status
+ * \param[in] ftr  Hub feature/status selector
+ *                 (0: connection, 2: suspend, 4: reset, 9: LS, 10: HS)
+ *
+ * \return     \c true if the status bit is 1
+ */
+bool _usb_h_rh_check_status(struct usb_h_desc *drv, uint8_t port, uint8_t ftr);
+
+/* Pipe transfer functions */
+
+/**
+ * @brief      Allocate a pipe for USB host communication
+ *
+ * @param      drv           The USB HCD driver
+ * @param[in]  dev           The device address
+ * @param[in]  ep            The endpoint address
+ * @param[in]  max_pkt_size  The endpoint maximum packet size
+ * @param[in]  attr          The endpoint attribute
+ * @param[in]  interval      The endpoint interval
+ *                           (bInterval of USB Endpoint Descriptor)
+ * @param[in]  speed         The transfer speed of the endpoint
+ * @param[in]  minimum_rsc   Minimum the resource usage, \sa usb_h_rsc_strategy
+ *
+ * @return     Pointer to allocated pipe structure instance
+ * @retval     NULL allocation fail
+ */
+struct usb_h_pipe *_usb_h_pipe_allocate(struct usb_h_desc *drv, uint8_t dev, uint8_t ep, uint16_t max_pkt_size,
+                                        uint8_t attr, uint8_t interval, uint8_t speed, bool minimum_rsc);
+
+/**
+ * @brief      Free an allocated pipe
+ *
+ * @param      pipe  The pipe
+ *
+ * @return     Operation result status
+ * @retval     ERR_BUSY Pipe is busy, use \ref _usb_h_pipe_abort to abort
+ * @retval     ERR_NONE Operation done successfully
+ */
+int32_t _usb_h_pipe_free(struct usb_h_pipe *pipe);
+
+/**
+ * @brief      Modify parameters of an allocated control pipe
+ *
+ * @param      pipe          The pipe
+ * @param[in]  dev           The device address
+ * @param[in]  ep            The endpoint address
+ * @param[in]  max_pkt_size  The maximum packet size, must be equal or
+ *                           less than allocated size
+ * @param[in]  speed         The working speed
+ *
+ * @return     Operation result status
+ * @retval     ERR_NOT_INITIALIZED Pipe is not allocated
+ * @retval     ERR_BUSY Pipe is busy transferring
+ * @retval     ERR_INVALID_ARG Argument error
+ * @retval     ERR_UNSUPPORTED_OP Pipe is not control pipe
+ * @retval     ERR_NONE Operation done successfully
+ */
+int32_t _usb_h_pipe_set_control_param(struct usb_h_pipe *pipe, uint8_t dev, uint8_t ep, uint16_t max_pkt_size,
+                                      uint8_t speed);
+
+/**
+ * @brief      Register transfer callback on a pipe
+ *
+ * @param      pipe  The pipe
+ * @param[in]  cb    Transfer callback function
+ *
+ * @return     Operation result status
+ * @retval     ERR_INVALID_ARG Argument error
+ * @retval     ERR_NONE Operation done successfully
+ */
+int32_t _usb_h_pipe_register_callback(struct usb_h_pipe *pipe, usb_h_pipe_cb_xfer_t cb);
+
+/**
+ * @brief      Issue a control transfer (request) on a pipe
+ *
+ * \note When there is data stage, timeout between data packets is 500ms, the
+ *       timeout between last data packet and the status packet is 50ms.
+ *
+ * @param         pipe    The pipe
+ * @param[in]     setup   Pointer to the setup packet
+ * @param[in,out] data    Pointer to the data buffer
+ * @param[in]     length  The data length
+ * @param[in]     timeout Timeout for whole request in ms
+ *
+ * @return     Operation result status
+ * @retval     ERR_NOT_INITIALIZED Pipe is not allocated
+ * @retval     ERR_BUSY Pipe is busy transferring
+ * @retval     ERR_INVALID_ARG Argument error
+ * @retval     ERR_UNSUPPORTED_OP Pipe is not control pipe
+ * @retval     ERR_NONE Operation done successfully
+ */
+int32_t _usb_h_control_xfer(struct usb_h_pipe *pipe, uint8_t *setup, uint8_t *data, uint16_t length, int16_t timeout);
+
+/**
+ * @brief      Issue a bulk / interrupt / iso transfer on a pipe
+ *
+ * @param         pipe     The pipe
+ * @param[in,out] data     Pointer to the data buffer
+ * @param[in]     length   The data length
+ * @param[in]     auto_zlp Auto append ZLP for OUT
+ *
+ * @return     Operation result status
+ * @retval     ERR_NOT_INITIALIZED Pipe is not allocated
+ * @retval     ERR_BUSY Pipe is busy transferring
+ * @retval     ERR_INVALID_ARG Argument error
+ * @retval     ERR_UNSUPPORTED_OP Pipe is control pipe
+ * @retval     ERR_NONE Operation done successfully
+ */
+int32_t _usb_h_bulk_int_iso_xfer(struct usb_h_pipe *pipe, uint8_t *data, uint32_t length, bool auto_zlp);
+
+/**
+ * @brief      Issue a periodic high bandwidth output on a pipe
+ *
+ * @param         pipe             The pipe
+ * @param[in,out] data             Pointer to the data buffer
+ * @param[in]     length           The data length
+ * @param[in]     trans_pkt_size   The transaction packet sizes in a micro frame,
+ *                                 0 to use endpoint max packet size
+ *
+ * @return     Operation result status
+ * @retval     ERR_NOT_INITIALIZED Pipe is not allocated
+ * @retval     ERR_BUSY Pipe is busy transferring
+ * @retval     ERR_INVALID_ARG Argument error
+ * @retval     ERR_UNSUPPORTED_OP Pipe is not high bandwidth periodic pipe, or
+ *                                DMA feature not enabled, or
+ *                                high bandwidth not enabled
+ * @retval     ERR_NONE Operation done successfully
+ */
+int32_t _usb_h_high_bw_out(struct usb_h_pipe *pipe, uint8_t *data, uint32_t length, uint16_t trans_pkt_size[3]);
+
+/**
+ * @brief      Check if pipe is busy transferring
+ *
+ * @param      pipe  The pipe
+ *
+ * @return     \c true if pipe is busy
+ */
+bool _usb_h_pipe_is_busy(struct usb_h_pipe *pipe);
+
+/**
+ * @brief      Abort pending transfer on a pipe
+ *
+ * @param      pipe  The pipe
+ */
+void _usb_h_pipe_abort(struct usb_h_pipe *pipe);
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif /* _HPL_USB_HOST_H_INCLUDED */
diff --git a/atmel-samd/asf4/samd21/hal/include/hpl_user_area.h b/atmel-samd/asf4/samd21/hal/include/hpl_user_area.h
new file mode 100644
index 000000000..b5c419bff
--- /dev/null
+++ b/atmel-samd/asf4/samd21/hal/include/hpl_user_area.h
@@ -0,0 +1,133 @@
+/**
+ * \file
+ *
+ * \brief Special user data area access
+ *
+ * Copyright (C) 2016 Atmel Corporation. All rights reserved.
+ *
+ * \asf_license_start
+ *
+ * \page License
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright notice,
+ *    this list of conditions and the following disclaimer.
+ *
+ * 2. Redistributions in binary form must reproduce the above copyright notice,
+ *    this list of conditions and the following disclaimer in the documentation
+ *    and/or other materials provided with the distribution.
+ *
+ * 3. The name of Atmel may not be used to endorse or promote products derived
+ *    from this software without specific prior written permission.
+ *
+ * 4. This software may only be redistributed and used in connection with an
+ *    Atmel microcontroller product.
+ *
+ * THIS SOFTWARE IS PROVIDED BY ATMEL "AS IS" AND ANY EXPRESS OR IMPLIED
+ * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
+ * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT ARE
+ * EXPRESSLY AND SPECIFICALLY DISCLAIMED. IN NO EVENT SHALL ATMEL BE LIABLE FOR
+ * ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+ * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
+ * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
+ * ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+ * POSSIBILITY OF SUCH DAMAGE.
+ *
+ * \asf_license_stop
+ *
+ */
+
+#ifndef _HPL_USER_DATA_H_INCLUDED
+#define _HPL_USER_DATA_H_INCLUDED
+
+#include <stdint.h>
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+/**
+ * \brief Read data from user data area
+ *
+ * The user data area could be the area that stores user data that is not erased
+ * with the flash contents, e.g.,
+ * - NVM Software Calibration Area of SAM D/L/C family
+ * - User Signature of SAM E/S/V 70
+ *
+ * \param[in]  base   The base address of the user area
+ * \param[in]  offset The byte offset of the data to be read inside the area
+ * \param[out] buf    Pointer to buffer to place the read data
+ * \param[in]  size   Size of data in number of bytes
+ *
+ * \return Operation status or bytes read.
+ * \retval ERR_NONE Data read successfully
+ * \retval ERR_UNSUPPORTED_OP base address not in any supported user area
+ * \retval ERR_BAD_ADDRESS offset not in right area
+ * \retval ERR_INVALID_ARG offset and size exceeds the right area
+ */
+int32_t _user_area_read(const void *base, const uint32_t offset, uint8_t *buf, const uint32_t size);
+
+/**
+ * \brief Read no more than 32 bits data from user data area
+ *
+ * When reading bits, the bitfield can cross 32-bis boundaries.
+ *
+ * \param[in] base       The base address of the user area
+ * \param[in] bit_offset Offset in number of bits
+ * \param[in] n_bits     Number of bits to read
+ * \return data read, assert if anything wrong (address not in user area
+ *         offset, size error, etc.).
+ */
+uint32_t _user_area_read_bits(const void *base, const uint32_t bit_offset, const uint8_t n_bits);
+
+/**
+ * \brief Write data to user data area
+ *
+ * The user data area could be the area that stores user data that is not erased
+ * with the flash contents, e.g.,
+ * - NVM Software Calibration Area of SAM D/L/C family
+ * - User Signature of SAM E/S/V 70
+ *
+ * When assigned offset and size exceeds the data area, error is reported.
+ *
+ * \param[out] base  The base address of the user area
+ * \param[in]  offset The offset of the data to be written inside the area
+ * \param[in]  buf    Pointer to buffer to place the written data
+ * \param[in]  size   Size of data in number of bytes
+ *
+ * \return Operation status or bytes writting.
+ * \retval ERR_NONE Data written successfully
+ * \retval ERR_UNSUPPORTED_OP base address not in any supported user area
+ * \retval ERR_DENIED Security bit is set
+ * \retval ERR_BAD_ADDRESS offset not in right area
+ * \retval ERR_INVALID_ARG offset and size exceeds the right area
+ */
+int32_t _user_area_write(void *base, const uint32_t offset, const uint8_t *buf, const uint32_t size);
+
+/**
+ * \brief Write no more than 32 bits data to user data area
+ *
+ * When writting bits, the bitfield can cross 32-bis boundaries.
+ *
+ * \param[out] base       The base address of the user area
+ * \param[in]  bit_offset Offset in number of bits
+ * \param[in]  bits       The data content
+ * \param[in]  n_bits     Number of bits to write
+ * \return Operation result
+ * \retval ERR_NONE Data written successfully
+ * \retval ERR_UNSUPPORTED_OP base address not in any supported user area
+ * \retval ERR_DENIED Security bit is set
+ * \retval ERR_BAD_ADDRESS offset not in right area
+ * \retval ERR_INVALID_ARG offset and size exceeds the right area
+ */
+int32_t _user_area_write_bits(void *base, const uint32_t bit_offset, const uint32_t bits, const uint8_t n_bits);
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif /* _HPL_USER_DATA_H_INCLUDED */