Merge remote-tracking branch 'adafruit/main' into cp-flow

8 files changed, 1053 insertions, 0 deletions

diff --git a/ports/raspberrypi/common-hal/busio/I2C.c b/ports/raspberrypi/common-hal/busio/I2C.c
new file mode 100644
index 000000000..fa49e375e
--- /dev/null
+++ b/ports/raspberrypi/common-hal/busio/I2C.c
@@ -0,0 +1,175 @@
+/*
+ * This file is part of the MicroPython project, http://micropython.org/
+ *
+ * The MIT License (MIT)
+ *
+ * Copyright (c) 2021 Scott Shawcroft for Adafruit Industries
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+ * THE SOFTWARE.
+ */
+
+#include "shared-bindings/busio/I2C.h"
+#include "py/mperrno.h"
+#include "py/runtime.h"
+
+#include "shared-bindings/microcontroller/__init__.h"
+#include "supervisor/shared/translate.h"
+
+#include "src/rp2_common/hardware_gpio/include/hardware/gpio.h"
+
+// Synopsys  DW_apb_i2c  (v2.01)  IP
+
+#define NO_PIN 0xff
+
+STATIC bool never_reset_i2c[2];
+STATIC i2c_inst_t* i2c[2] = {i2c0, i2c1};
+
+void reset_i2c(void) {
+    for (size_t i = 0; i < 2; i++) {
+        if (never_reset_i2c[i]) {
+            continue;
+        }
+
+        i2c_deinit(i2c[i]);
+    }
+}
+
+void common_hal_busio_i2c_construct(busio_i2c_obj_t *self,
+        const mcu_pin_obj_t* scl, const mcu_pin_obj_t* sda, uint32_t frequency, uint32_t timeout) {
+    self->peripheral = NULL;
+    // I2C pins have a regular pattern. SCL is always odd and SDA is even. They match up in pairs
+    // so we can divide by two to get the instance. This pattern repeats.
+    if (scl->number % 2 == 1 && sda->number % 2 == 0 && scl->number / 2 == sda->number / 2) {
+        size_t instance = (scl->number / 2) % 2;
+        self->peripheral = i2c[instance];
+    }
+    if (self->peripheral == NULL) {
+        mp_raise_ValueError(translate("Invalid pins"));
+    }
+    if ((i2c_get_hw(self->peripheral)->enable & I2C_IC_ENABLE_ENABLE_BITS) != 0) {
+        mp_raise_ValueError(translate("I2C peripheral in use"));
+    }
+    if (frequency > 1000000) {
+        mp_raise_ValueError(translate("Unsupported baudrate"));
+    }
+
+#if CIRCUITPY_REQUIRE_I2C_PULLUPS
+    // Test that the pins are in a high state. (Hopefully indicating they are pulled up.)
+    gpio_set_function(sda->number, GPIO_FUNC_SIO);
+    gpio_set_function(scl->number, GPIO_FUNC_SIO);
+    gpio_set_dir(sda->number, GPIO_IN);
+    gpio_set_dir(scl->number, GPIO_IN);
+
+    gpio_set_pulls(sda->number, false, true);
+    gpio_set_pulls(scl->number, false, true);
+
+    common_hal_mcu_delay_us(10);
+
+    gpio_set_pulls(sda->number, false, false);
+    gpio_set_pulls(scl->number, false, false);
+
+    // We must pull up within 3us to achieve 400khz.
+    common_hal_mcu_delay_us(3);
+
+    if (!gpio_get(sda->number) || !gpio_get(scl->number)) {
+        reset_pin_number(sda->number);
+        reset_pin_number(scl->number);
+        mp_raise_RuntimeError(translate("SDA or SCL needs a pull up"));
+    }
+#endif
+
+    gpio_set_function(sda->number, GPIO_FUNC_I2C);
+    gpio_set_function(scl->number, GPIO_FUNC_I2C);
+
+    self->baudrate = i2c_init(self->peripheral, frequency);
+
+    self->sda_pin = sda->number;
+    self->scl_pin = scl->number;
+    claim_pin(sda);
+    claim_pin(scl);
+}
+
+bool common_hal_busio_i2c_deinited(busio_i2c_obj_t *self) {
+    return self->sda_pin == NO_PIN;
+}
+
+void common_hal_busio_i2c_deinit(busio_i2c_obj_t *self) {
+    if (common_hal_busio_i2c_deinited(self)) {
+        return;
+    }
+    never_reset_i2c[i2c_hw_index(self->peripheral)] = false;
+
+    i2c_deinit(self->peripheral);
+
+    reset_pin_number(self->sda_pin);
+    reset_pin_number(self->scl_pin);
+    self->sda_pin = NO_PIN;
+    self->scl_pin = NO_PIN;
+}
+
+bool common_hal_busio_i2c_probe(busio_i2c_obj_t *self, uint8_t addr) {
+    uint8_t fake_read = 0;
+    return i2c_read_blocking(self->peripheral, addr, &fake_read, 1, false) != PICO_ERROR_GENERIC;
+}
+
+bool common_hal_busio_i2c_try_lock(busio_i2c_obj_t *self) {
+    bool grabbed_lock = false;
+    if (!self->has_lock) {
+        grabbed_lock = true;
+        self->has_lock = true;
+    }
+    return grabbed_lock;
+}
+
+bool common_hal_busio_i2c_has_lock(busio_i2c_obj_t *self) {
+    return self->has_lock;
+}
+
+void common_hal_busio_i2c_unlock(busio_i2c_obj_t *self) {
+    self->has_lock = false;
+}
+
+uint8_t common_hal_busio_i2c_write(busio_i2c_obj_t *self, uint16_t addr,
+                                   const uint8_t *data, size_t len, bool transmit_stop_bit) {
+    int result = i2c_write_blocking(self->peripheral, addr, data, len, !transmit_stop_bit);
+    if (result == len) {
+        return 0;
+    } else if (result == PICO_ERROR_GENERIC) {
+        return MP_ENODEV;
+    }
+    return MP_EIO;
+}
+
+uint8_t common_hal_busio_i2c_read(busio_i2c_obj_t *self, uint16_t addr,
+        uint8_t *data, size_t len) {
+    int result = i2c_read_blocking(self->peripheral, addr, data, len, false);
+    if (result == len) {
+        return 0;
+    } else if (result == PICO_ERROR_GENERIC) {
+        return MP_ENODEV;
+    }
+    return MP_EIO;
+}
+
+void common_hal_busio_i2c_never_reset(busio_i2c_obj_t *self) {
+    never_reset_i2c[i2c_hw_index(self->peripheral)] = true;
+
+    never_reset_pin_number(self->scl_pin);
+    never_reset_pin_number(self->sda_pin);
+}
diff --git a/ports/raspberrypi/common-hal/busio/I2C.h b/ports/raspberrypi/common-hal/busio/I2C.h
new file mode 100644
index 000000000..d09f29e54
--- /dev/null
+++ b/ports/raspberrypi/common-hal/busio/I2C.h
@@ -0,0 +1,47 @@
+/*
+ * This file is part of the MicroPython project, http://micropython.org/
+ *
+ * The MIT License (MIT)
+ *
+ * Copyright (c) 2021 Scott Shawcroft for Adafruit Industries
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+ * THE SOFTWARE.
+ */
+
+#ifndef MICROPY_INCLUDED_RASPBERRYPI_COMMON_HAL_BUSIO_I2C_H
+#define MICROPY_INCLUDED_RASPBERRYPI_COMMON_HAL_BUSIO_I2C_H
+
+#include "common-hal/microcontroller/Pin.h"
+
+#include "py/obj.h"
+
+#include "src/rp2_common/hardware_i2c/include/hardware/i2c.h"
+
+typedef struct {
+    mp_obj_base_t base;
+    i2c_inst_t * peripheral;
+    bool has_lock;
+    uint baudrate;
+    uint8_t scl_pin;
+    uint8_t sda_pin;
+} busio_i2c_obj_t;
+
+void reset_i2c(void);
+
+#endif // MICROPY_INCLUDED_RASPBERRYPI_COMMON_HAL_BUSIO_I2C_H
diff --git a/ports/raspberrypi/common-hal/busio/OneWire.h b/ports/raspberrypi/common-hal/busio/OneWire.h
new file mode 100644
index 000000000..e27723ab2
--- /dev/null
+++ b/ports/raspberrypi/common-hal/busio/OneWire.h
@@ -0,0 +1,33 @@
+/*
+ * This file is part of the MicroPython project, http://micropython.org/
+ *
+ * The MIT License (MIT)
+ *
+ * Copyright (c) 2021 Scott Shawcroft for Adafruit Industries
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+ * THE SOFTWARE.
+ */
+
+#ifndef MICROPY_INCLUDED_RASPBERRYPI_COMMON_HAL_BUSIO_ONEWIRE_H
+#define MICROPY_INCLUDED_RASPBERRYPI_COMMON_HAL_BUSIO_ONEWIRE_H
+
+// Use bitbangio.
+#include "shared-module/busio/OneWire.h"
+
+#endif // MICROPY_INCLUDED_RASPBERRYPI_COMMON_HAL_BUSIO_ONEWIRE_H
diff --git a/ports/raspberrypi/common-hal/busio/SPI.c b/ports/raspberrypi/common-hal/busio/SPI.c
new file mode 100644
index 000000000..b157ae3eb
--- /dev/null
+++ b/ports/raspberrypi/common-hal/busio/SPI.c
@@ -0,0 +1,294 @@
+/*
+ * This file is part of the MicroPython project, http://micropython.org/
+ *
+ * The MIT License (MIT)
+ *
+ * Copyright (c) 2021 Scott Shawcroft for Adafruit Industries
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+ * THE SOFTWARE.
+ */
+
+#include "shared-bindings/busio/SPI.h"
+
+#include "lib/utils/interrupt_char.h"
+#include "py/mperrno.h"
+#include "py/runtime.h"
+
+#include "supervisor/board.h"
+#include "common-hal/microcontroller/Pin.h"
+#include "supervisor/shared/rgb_led_status.h"
+#include "shared-bindings/microcontroller/Pin.h"
+
+#include "src/rp2_common/hardware_dma/include/hardware/dma.h"
+#include "src/rp2_common/hardware_gpio/include/hardware/gpio.h"
+
+#define NO_INSTANCE 0xff
+
+STATIC bool never_reset_spi[2];
+STATIC spi_inst_t* spi[2] = {spi0, spi1};
+
+void reset_spi(void) {
+    for (size_t i = 0; i < 2; i++) {
+        if (never_reset_spi[i]) {
+            continue;
+        }
+
+        spi_deinit(spi[i]);
+    }
+}
+
+void common_hal_busio_spi_construct(busio_spi_obj_t *self,
+        const mcu_pin_obj_t * clock, const mcu_pin_obj_t * mosi,
+        const mcu_pin_obj_t * miso) {
+    size_t instance_index = NO_INSTANCE;
+    if (clock->number % 4 == 2) {
+        instance_index = (clock->number / 8) % 2;
+    }
+    if (mosi != NULL) {
+        // Make sure the set MOSI matches the clock settings.
+        if (mosi->number % 4 != 3 ||
+            (mosi->number / 8) % 2 != instance_index) {
+            instance_index = NO_INSTANCE;
+        }
+    }
+    if (miso != NULL) {
+        // Make sure the set MOSI matches the clock settings.
+        if (miso->number % 4 != 0 ||
+            (miso->number / 8) % 2 != instance_index) {
+            instance_index = NO_INSTANCE;
+        }
+    }
+
+    // TODO: Check to see if we're sharing the SPI with a native APA102.
+
+    if (instance_index > 1) {
+        mp_raise_ValueError(translate("Invalid pins"));
+    }
+
+    if (instance_index == 0) {
+        self->peripheral = spi0;
+    } else if (instance_index == 1) {
+        self->peripheral = spi1;
+    }
+
+    if ((spi_get_hw(self->peripheral)->cr1 & SPI_SSPCR1_SSE_BITS) != 0) {
+        mp_raise_ValueError(translate("SPI peripheral in use"));
+    }
+
+    spi_init(self->peripheral, 250000);
+
+    gpio_set_function(clock->number, GPIO_FUNC_SPI);
+    claim_pin(clock);
+    self->clock = clock;
+
+    self->MOSI = mosi;
+    if (mosi != NULL) {
+        gpio_set_function(mosi->number, GPIO_FUNC_SPI);
+        claim_pin(mosi);
+    }
+
+    self->MISO = miso;
+    if (miso != NULL) {
+        gpio_set_function(miso->number, GPIO_FUNC_SPI);
+        claim_pin(miso);
+    }
+}
+
+void common_hal_busio_spi_never_reset(busio_spi_obj_t *self) {
+    never_reset_spi[spi_get_index(self->peripheral)] = true;
+
+    common_hal_never_reset_pin(self->clock);
+    common_hal_never_reset_pin(self->MOSI);
+    common_hal_never_reset_pin(self->MISO);
+}
+
+bool common_hal_busio_spi_deinited(busio_spi_obj_t *self) {
+    return self->clock == NULL;
+}
+
+void common_hal_busio_spi_deinit(busio_spi_obj_t *self) {
+    if (common_hal_busio_spi_deinited(self)) {
+        return;
+    }
+    never_reset_spi[spi_get_index(self->peripheral)] = false;
+    spi_deinit(self->peripheral);
+
+    common_hal_reset_pin(self->clock);
+    common_hal_reset_pin(self->MOSI);
+    common_hal_reset_pin(self->MISO);
+    self->clock = NULL;
+}
+
+bool common_hal_busio_spi_configure(busio_spi_obj_t *self,
+        uint32_t baudrate, uint8_t polarity, uint8_t phase, uint8_t bits) {
+    if (baudrate == self->target_frequency &&
+        polarity == self->polarity &&
+        phase == self->phase &&
+        bits == self->bits) {
+        return true;
+    }
+
+    spi_set_format(self->peripheral, bits, polarity, phase, SPI_MSB_FIRST);
+
+    self->polarity = polarity;
+    self->phase = phase;
+    self->bits = bits;
+    self->target_frequency = baudrate;
+    self->real_frequency = spi_set_baudrate(self->peripheral, baudrate);
+
+    return true;
+}
+
+bool common_hal_busio_spi_try_lock(busio_spi_obj_t *self) {
+    bool grabbed_lock = false;
+    if (!self->has_lock) {
+        grabbed_lock = true;
+        self->has_lock = true;
+    }
+    return grabbed_lock;
+}
+
+bool common_hal_busio_spi_has_lock(busio_spi_obj_t *self) {
+    return self->has_lock;
+}
+
+void common_hal_busio_spi_unlock(busio_spi_obj_t *self) {
+    self->has_lock = false;
+}
+
+static bool _transfer(busio_spi_obj_t *self,
+    const uint8_t *data_out, size_t out_len,
+    uint8_t *data_in, size_t in_len) {
+    // Use DMA for large transfers if channels are available
+    const size_t dma_min_size_threshold = 32;
+    int chan_tx = -1;
+    int chan_rx = -1;
+    size_t len = MAX(out_len, in_len);
+    if (len >= dma_min_size_threshold) {
+        // Use two DMA channels to service the two FIFOs
+        chan_tx = dma_claim_unused_channel(false);
+        chan_rx = dma_claim_unused_channel(false);
+    }
+    bool use_dma = chan_rx >= 0 && chan_tx >= 0;
+    if (use_dma) {
+        dma_channel_config c = dma_channel_get_default_config(chan_tx);
+        channel_config_set_transfer_data_size(&c, DMA_SIZE_8);
+        channel_config_set_dreq(&c, spi_get_index(self->peripheral) ? DREQ_SPI1_TX : DREQ_SPI0_TX);
+        channel_config_set_read_increment(&c, out_len == len);
+        channel_config_set_write_increment(&c, false);
+        dma_channel_configure(chan_tx, &c,
+            &spi_get_hw(self->peripheral)->dr,
+            data_out,
+            len,
+            false);
+
+        c = dma_channel_get_default_config(chan_rx);
+        channel_config_set_transfer_data_size(&c, DMA_SIZE_8);
+        channel_config_set_dreq(&c, spi_get_index(self->peripheral) ? DREQ_SPI1_RX : DREQ_SPI0_RX);
+        channel_config_set_read_increment(&c, false);
+        channel_config_set_write_increment(&c, in_len == len);
+        dma_channel_configure(chan_rx, &c,
+            data_in,
+            &spi_get_hw(self->peripheral)->dr,
+            len,
+            false);
+
+        dma_start_channel_mask((1u << chan_rx) | (1u << chan_tx));
+        while (dma_channel_is_busy(chan_rx) || dma_channel_is_busy(chan_tx)) {
+            // TODO: We should idle here until we get a DMA interrupt or something else.
+            RUN_BACKGROUND_TASKS;
+            if (mp_hal_is_interrupted()) {
+                if (dma_channel_is_busy(chan_rx)) {
+                    dma_channel_abort(chan_rx);
+                }
+                if (dma_channel_is_busy(chan_tx)) {
+                    dma_channel_abort(chan_tx);
+                }
+                break;
+            }
+        }
+    }
+
+    // If we have claimed only one channel successfully, we should release immediately. This also
+    // releases the DMA after use_dma has been done.
+    if (chan_rx >= 0) {
+        dma_channel_unclaim(chan_rx);
+    }
+    if (chan_tx >= 0) {
+        dma_channel_unclaim(chan_tx);
+    }
+
+    if (!use_dma && !mp_hal_is_interrupted()) {
+        // Use software for small transfers, or if couldn't claim two DMA channels
+        // Never have more transfers in flight than will fit into the RX FIFO,
+        // else FIFO will overflow if this code is heavily interrupted.
+        const size_t fifo_depth = 8;
+        size_t rx_remaining = len;
+        size_t tx_remaining = len;
+
+        while (!mp_hal_is_interrupted() && (rx_remaining || tx_remaining)) {
+            if (tx_remaining && spi_is_writable(self->peripheral) && rx_remaining - tx_remaining < fifo_depth) {
+                spi_get_hw(self->peripheral)->dr = (uint32_t) *data_out;
+                // Increment only if the buffer is the transfer length. It's 1 otherwise.
+                if (out_len == len) {
+                    data_out++;
+                }
+                --tx_remaining;
+            }
+            if (rx_remaining && spi_is_readable(self->peripheral)) {
+                *data_in = (uint8_t) spi_get_hw(self->peripheral)->dr;
+                // Increment only if the buffer is the transfer length. It's 1 otherwise.
+                if (in_len == len) {
+                    data_in++;
+                }
+                --rx_remaining;
+            }
+            RUN_BACKGROUND_TASKS;
+        }
+    }
+    return true;
+}
+
+bool common_hal_busio_spi_write(busio_spi_obj_t *self,
+        const uint8_t *data, size_t len) {
+    uint32_t data_in;
+    return _transfer(self, data, len, (uint8_t*) &data_in, MIN(len, 4));
+}
+
+bool common_hal_busio_spi_read(busio_spi_obj_t *self,
+        uint8_t *data, size_t len, uint8_t write_value) {
+    uint32_t data_out = write_value << 24 | write_value << 16 | write_value << 8 | write_value;
+    return _transfer(self, (const uint8_t*) &data_out, MIN(4, len), data, len);
+}
+
+bool common_hal_busio_spi_transfer(busio_spi_obj_t *self, const uint8_t *data_out, uint8_t *data_in, size_t len) {
+    return _transfer(self, data_out, len, data_in, len);
+}
+
+uint32_t common_hal_busio_spi_get_frequency(busio_spi_obj_t* self) {
+    return self->real_frequency;
+}
+
+uint8_t common_hal_busio_spi_get_phase(busio_spi_obj_t* self) {
+    return self->phase;
+}
+
+uint8_t common_hal_busio_spi_get_polarity(busio_spi_obj_t* self) {
+    return self->polarity;
+}
diff --git a/ports/raspberrypi/common-hal/busio/SPI.h b/ports/raspberrypi/common-hal/busio/SPI.h
new file mode 100644
index 000000000..981db46d4
--- /dev/null
+++ b/ports/raspberrypi/common-hal/busio/SPI.h
@@ -0,0 +1,52 @@
+/*
+ * This file is part of the MicroPython project, http://micropython.org/
+ *
+ * The MIT License (MIT)
+ *
+ * Copyright (c) 2021 Scott Shawcroft for Adafruit Industries
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+ * THE SOFTWARE.
+ */
+
+#ifndef MICROPY_INCLUDED_RASPBERRYPI_COMMON_HAL_BUSIO_SPI_H
+#define MICROPY_INCLUDED_RASPBERRYPI_COMMON_HAL_BUSIO_SPI_H
+
+#include "common-hal/microcontroller/Pin.h"
+
+#include "py/obj.h"
+
+#include "src/rp2_common/hardware_spi/include/hardware/spi.h"
+
+typedef struct {
+    mp_obj_base_t base;
+    spi_inst_t * peripheral;
+    bool has_lock;
+    const mcu_pin_obj_t* clock;
+    const mcu_pin_obj_t* MOSI;
+    const mcu_pin_obj_t* MISO;
+    uint32_t target_frequency;
+    int32_t real_frequency;
+    uint8_t polarity;
+    uint8_t phase;
+    uint8_t bits;
+} busio_spi_obj_t;
+
+void reset_spi(void);
+
+#endif // MICROPY_INCLUDED_RASPBERRYPI_COMMON_HAL_BUSIO_SPI_H
diff --git a/ports/raspberrypi/common-hal/busio/UART.c b/ports/raspberrypi/common-hal/busio/UART.c
new file mode 100644
index 000000000..f9a75b499
--- /dev/null
+++ b/ports/raspberrypi/common-hal/busio/UART.c
@@ -0,0 +1,404 @@
+/*
+ * This file is part of the MicroPython project, http://micropython.org/
+ *
+ * The MIT License (MIT)
+ *
+ * Copyright (c) 2021 Scott Shawcroft for Adafruit Industries
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+ * THE SOFTWARE.
+ */
+
+#include "shared-bindings/microcontroller/__init__.h"
+#include "shared-bindings/busio/UART.h"
+
+#include "mpconfigport.h"
+#include "lib/utils/interrupt_char.h"
+#include "py/gc.h"
+#include "py/mperrno.h"
+#include "py/runtime.h"
+#include "py/stream.h"
+#include "supervisor/shared/translate.h"
+#include "supervisor/shared/tick.h"
+
+#define UART_DEBUG(...) (void)0
+// #define UART_DEBUG(...) mp_printf(&mp_plat_print __VA_OPT__(,) __VA_ARGS__)
+
+// Do-nothing callback needed so that usart_async code will enable rx interrupts.
+// See comment below re usart_async_register_callback()
+// static void usart_async_rxc_callback(const struct usart_async_descriptor *const descr) {
+//     // Nothing needs to be done by us.
+// }
+
+#define NO_PIN 0xff
+
+void common_hal_busio_uart_construct(busio_uart_obj_t *self,
+    const mcu_pin_obj_t * tx, const mcu_pin_obj_t * rx,
+    const mcu_pin_obj_t * rts, const mcu_pin_obj_t * cts,
+    const mcu_pin_obj_t * rs485_dir, bool rs485_invert,
+    uint32_t baudrate, uint8_t bits, busio_uart_parity_t parity, uint8_t stop,
+    mp_float_t timeout, uint16_t receiver_buffer_size, byte* receiver_buffer,
+    bool sigint_enabled) {
+    mp_raise_NotImplementedError(translate("UART not yet supported"));
+
+//     Sercom* sercom = NULL;
+//     uint8_t sercom_index = 255; // Unset index
+//     uint32_t rx_pinmux = 0;
+//     uint8_t rx_pad = 255; // Unset pad
+//     uint32_t tx_pinmux = 0;
+//     uint8_t tx_pad = 255; // Unset pad
+
+//     if ((rts != NULL) || (cts != NULL) || (rs485_dir != NULL) || (rs485_invert)) {
+//         mp_raise_ValueError(translate("RTS/CTS/RS485 Not yet supported on this device"));
+//     }
+
+//     if (bits > 8) {
+//         mp_raise_NotImplementedError(translate("bytes > 8 bits not supported"));
+//     }
+
+//     bool have_tx = tx != NULL;
+//     bool have_rx = rx != NULL;
+//     if (!have_tx && !have_rx) {
+//         mp_raise_ValueError(translate("tx and rx cannot both be None"));
+//     }
+
+//     self->baudrate = baudrate;
+//     self->character_bits = bits;
+//     self->timeout_ms = timeout * 1000;
+
+//     // This assignment is only here because the usart_async routines take a *const argument.
+//     struct usart_async_descriptor * const usart_desc_p = (struct usart_async_descriptor * const) &self->usart_desc;
+
+//     for (int i = 0; i < NUM_SERCOMS_PER_PIN; i++) {
+//         Sercom* potential_sercom = NULL;
+//         if (have_tx) {
+//             sercom_index = tx->sercom[i].index;
+//             if (sercom_index >= SERCOM_INST_NUM) {
+//                 continue;
+//             }
+//             potential_sercom = sercom_insts[sercom_index];
+// #ifdef SAMD21
+// 	    if (potential_sercom->USART.CTRLA.bit.ENABLE != 0 ||
+//                 !(tx->sercom[i].pad == 0 ||
+//                   tx->sercom[i].pad == 2)) {
+//                 continue;
+//             }
+// #endif
+// #ifdef SAM_D5X_E5X
+// 	    if (potential_sercom->USART.CTRLA.bit.ENABLE != 0 ||
+//                 !(tx->sercom[i].pad == 0)) {
+//                 continue;
+//             }
+// #endif
+//             tx_pinmux = PINMUX(tx->number, (i == 0) ? MUX_C : MUX_D);
+//             tx_pad = tx->sercom[i].pad;
+//             if (rx == NULL) {
+//                 sercom = potential_sercom;
+//                 break;
+//             }
+//         }
+//         for (int j = 0; j < NUM_SERCOMS_PER_PIN; j++) {
+//             if (((!have_tx && rx->sercom[j].index < SERCOM_INST_NUM &&
+//                   sercom_insts[rx->sercom[j].index]->USART.CTRLA.bit.ENABLE == 0) ||
+//                  sercom_index == rx->sercom[j].index) &&
+//                 rx->sercom[j].pad != tx_pad) {
+//                 rx_pinmux = PINMUX(rx->number, (j == 0) ? MUX_C : MUX_D);
+//                 rx_pad = rx->sercom[j].pad;
+//                 sercom = sercom_insts[rx->sercom[j].index];
+//                 sercom_index = rx->sercom[j].index;
+//                 break;
+//             }
+//         }
+//         if (sercom != NULL) {
+//             break;
+//         }
+//     }
+//     if (sercom == NULL) {
+//         mp_raise_ValueError(translate("Invalid pins"));
+//     }
+//     if (!have_tx) {
+//         tx_pad = 0;
+//         if (rx_pad == 0) {
+//             tx_pad = 2;
+//         }
+//     }
+//     if (!have_rx) {
+//         rx_pad = (tx_pad + 1) % 4;
+//     }
+
+//     // Set up clocks on SERCOM.
+//     samd_peripherals_sercom_clock_init(sercom, sercom_index);
+
+//     if (rx && receiver_buffer_size > 0) {
+//         self->buffer_length = receiver_buffer_size;
+//         // Initially allocate the UART's buffer in the long-lived part of the
+//         // heap.  UARTs are generally long-lived objects, but the "make long-
+//         // lived" machinery is incapable of moving internal pointers like
+//         // self->buffer, so do it manually.  (However, as long as internal
+//         // pointers like this are NOT moved, allocating the buffer
+//         // in the long-lived pool is not strictly necessary)
+//         self->buffer = (uint8_t *) gc_alloc(self->buffer_length * sizeof(uint8_t), false, true);
+//         if (self->buffer == NULL) {
+//             common_hal_busio_uart_deinit(self);
+//             mp_raise_msg_varg(&mp_type_MemoryError, translate("Failed to allocate RX buffer of %d bytes"), self->buffer_length * sizeof(uint8_t));
+//         }
+//     } else {
+//         self->buffer_length = 0;
+//         self->buffer = NULL;
+//     }
+
+//     if (usart_async_init(usart_desc_p, sercom, self->buffer, self->buffer_length, NULL) != ERR_NONE) {
+//         mp_raise_ValueError(translate("Could not initialize UART"));
+//     }
+
+//     // usart_async_init() sets a number of defaults based on a prototypical SERCOM
+//     // which don't necessarily match what we need. After calling it, set the values
+//     // specific to this instantiation of UART.
+
+//     // Set pads computed for this SERCOM.
+//     // TXPO:
+//     // 0x0: TX pad 0; no RTS/CTS
+//     // 0x1: TX pad 2; no RTS/CTS
+//     // 0x2: TX pad 0; RTS: pad 2, CTS: pad 3 (not used by us right now)
+//     // So divide by 2 to map pad to value.
+//     // RXPO:
+//     // 0x0: RX pad 0
+//     // 0x1: RX pad 1
+//     // 0x2: RX pad 2
+//     // 0x3: RX pad 3
+
+//     // Doing a group mask and set of the registers saves 60 bytes over setting the bitfields individually.
+
+//     sercom->USART.CTRLA.reg &= ~(SERCOM_USART_CTRLA_TXPO_Msk |
+//                                  SERCOM_USART_CTRLA_RXPO_Msk |
+//                                  SERCOM_USART_CTRLA_FORM_Msk);
+//     sercom->USART.CTRLA.reg |= SERCOM_USART_CTRLA_TXPO(tx_pad / 2) |
+//                                SERCOM_USART_CTRLA_RXPO(rx_pad) |
+//                                (parity == BUSIO_UART_PARITY_NONE ? 0 : SERCOM_USART_CTRLA_FORM(1));
+
+//     // Enable tx and/or rx based on whether the pins were specified.
+//     // CHSIZE is 0 for 8 bits, 5, 6, 7 for 5, 6, 7 bits. 1 for 9 bits, but we don't support that.
+//     sercom->USART.CTRLB.reg &= ~(SERCOM_USART_CTRLB_TXEN |
+//                                  SERCOM_USART_CTRLB_RXEN |
+//                                  SERCOM_USART_CTRLB_PMODE |
+//                                  SERCOM_USART_CTRLB_SBMODE |
+//                                  SERCOM_USART_CTRLB_CHSIZE_Msk);
+//     sercom->USART.CTRLB.reg |= (have_tx ? SERCOM_USART_CTRLB_TXEN : 0) |
+//                                (have_rx ? SERCOM_USART_CTRLB_RXEN : 0) |
+//                                (parity == BUSIO_UART_PARITY_ODD ? SERCOM_USART_CTRLB_PMODE : 0) |
+//                                (stop > 1 ? SERCOM_USART_CTRLB_SBMODE : 0) |
+//                                SERCOM_USART_CTRLB_CHSIZE(bits % 8);
+
+//     // Set baud rate
+//     common_hal_busio_uart_set_baudrate(self, baudrate);
+
+//     // Turn on rx interrupt handling. The UART async driver has its own set of internal callbacks,
+//     // which are set up by uart_async_init(). These in turn can call user-specified callbacks.
+//     // In fact, the actual interrupts are not enabled unless we set up a user-specified callback.
+//     // This is confusing. It's explained in the Atmel START User Guide -> Implementation Description ->
+//     // Different read function behavior in some asynchronous drivers. As of this writing:
+//     // http://start.atmel.com/static/help/index.html?GUID-79201A5A-226F-4FBB-B0B8-AB0BE0554836
+//     // Look at the ASFv4 code example for async USART.
+//     usart_async_register_callback(usart_desc_p, USART_ASYNC_RXC_CB, usart_async_rxc_callback);
+
+
+//     if (have_tx) {
+//         gpio_set_pin_direction(tx->number, GPIO_DIRECTION_OUT);
+//         gpio_set_pin_pull_mode(tx->number, GPIO_PULL_OFF);
+//         gpio_set_pin_function(tx->number, tx_pinmux);
+//         self->tx_pin  = tx->number;
+//         claim_pin(tx);
+//     } else {
+//         self->tx_pin = NO_PIN;
+//     }
+
+//     if (have_rx) {
+//         gpio_set_pin_direction(rx->number, GPIO_DIRECTION_IN);
+//         gpio_set_pin_pull_mode(rx->number, GPIO_PULL_OFF);
+//         gpio_set_pin_function(rx->number, rx_pinmux);
+//         self->rx_pin  = rx->number;
+//         claim_pin(rx);
+//     } else {
+//         self->rx_pin = NO_PIN;
+//     }
+
+//     usart_async_enable(usart_desc_p);
+}
+
+bool common_hal_busio_uart_deinited(busio_uart_obj_t *self) {
+    return self->rx_pin == NO_PIN && self->tx_pin == NO_PIN;
+}
+
+void common_hal_busio_uart_deinit(busio_uart_obj_t *self) {
+    if (common_hal_busio_uart_deinited(self)) {
+        return;
+    }
+    // This assignment is only here because the usart_async routines take a *const argument.
+    // struct usart_async_descriptor * const usart_desc_p = (struct usart_async_descriptor * const) &self->usart_desc;
+    // usart_async_disable(usart_desc_p);
+    // usart_async_deinit(usart_desc_p);
+    reset_pin_number(self->rx_pin);
+    reset_pin_number(self->tx_pin);
+    self->rx_pin = NO_PIN;
+    self->tx_pin = NO_PIN;
+}
+
+// Read characters.
+size_t common_hal_busio_uart_read(busio_uart_obj_t *self, uint8_t *data, size_t len, int *errcode) {
+    if (self->rx_pin == NO_PIN) {
+        mp_raise_ValueError(translate("No RX pin"));
+    }
+
+    // This assignment is only here because the usart_async routines take a *const argument.
+    // struct usart_async_descriptor * const usart_desc_p = (struct usart_async_descriptor * const) &self->usart_desc;
+
+    if (len == 0) {
+        // Nothing to read.
+        return 0;
+    }
+
+    // struct io_descriptor *io;
+    // usart_async_get_io_descriptor(usart_desc_p, &io);
+
+    size_t total_read = 0;
+    // uint64_t start_ticks = supervisor_ticks_ms64();
+
+    // // Busy-wait until timeout or until we've read enough chars.
+    // while (supervisor_ticks_ms64() - start_ticks <= self->timeout_ms) {
+    //     // Read as many chars as we can right now, up to len.
+    //     size_t num_read = io_read(io, data, len);
+
+    //     // Advance pointer in data buffer, and decrease how many chars left to read.
+    //     data += num_read;
+    //     len -= num_read;
+    //     total_read += num_read;
+    //     if (len == 0) {
+    //         // Don't need to read any more: data buf is full.
+    //         break;
+    //     }
+    //     if (num_read > 0) {
+    //         // Reset the timeout on every character read.
+    //         start_ticks = supervisor_ticks_ms64();
+    //     }
+    //     RUN_BACKGROUND_TASKS;
+    //     // Allow user to break out of a timeout with a KeyboardInterrupt.
+    //     if (mp_hal_is_interrupted()) {
+    //         break;
+    //     }
+    //     // If we are zero timeout, make sure we don't loop again (in the event
+    //     // we read in under 1ms)
+    //     if (self->timeout_ms == 0) {
+    //         break;
+    //     }
+    // }
+
+    // if (total_read == 0) {
+    //     *errcode = EAGAIN;
+    //     return MP_STREAM_ERROR;
+    // }
+
+    return total_read;
+}
+
+// Write characters.
+size_t common_hal_busio_uart_write(busio_uart_obj_t *self, const uint8_t *data, size_t len, int *errcode) {
+    if (self->tx_pin == NO_PIN) {
+        mp_raise_ValueError(translate("No TX pin"));
+    }
+
+    // This assignment is only here because the usart_async routines take a *const argument.
+    // struct usart_async_descriptor * const usart_desc_p = (struct usart_async_descriptor * const) &self->usart_desc;
+
+    // struct io_descriptor *io;
+    // usart_async_get_io_descriptor(usart_desc_p, &io);
+
+    // // Start writing characters. This is non-blocking and will
+    // // return immediately after setting up the write.
+    // if (io_write(io, data, len) < 0) {
+    //     *errcode = MP_EAGAIN;
+    //     return MP_STREAM_ERROR;
+    // }
+
+    // // Busy-wait until all characters transmitted.
+    // struct usart_async_status async_status;
+    // while (true) {
+    //     usart_async_get_status(usart_desc_p, &async_status);
+    //     if (async_status.txcnt >= len) {
+    //         break;
+    //     }
+    //     RUN_BACKGROUND_TASKS;
+    // }
+
+    return len;
+}
+
+uint32_t common_hal_busio_uart_get_baudrate(busio_uart_obj_t *self) {
+    return self->baudrate;
+}
+
+void common_hal_busio_uart_set_baudrate(busio_uart_obj_t *self, uint32_t baudrate) {
+    // This assignment is only here because the usart_async routines take a *const argument.
+    // struct usart_async_descriptor * const usart_desc_p = (struct usart_async_descriptor * const) &self->usart_desc;
+    // usart_async_set_baud_rate(usart_desc_p,
+    //                           // Samples and ARITHMETIC vs FRACTIONAL must correspond to USART_SAMPR in
+    //                           // hpl_sercom_config.h.
+    //                           _usart_async_calculate_baud_rate(baudrate,  // e.g. 9600 baud
+    //                                                            PROTOTYPE_SERCOM_USART_ASYNC_CLOCK_FREQUENCY,
+    //                                                            16,   // samples
+    //                                                            USART_BAUDRATE_ASYNCH_ARITHMETIC,
+    //                                                            0  // fraction - not used for ARITHMETIC
+    //                                                            ));
+    self->baudrate = baudrate;
+}
+
+mp_float_t common_hal_busio_uart_get_timeout(busio_uart_obj_t *self) {
+    return (mp_float_t) (self->timeout_ms / 1000.0f);
+}
+
+void common_hal_busio_uart_set_timeout(busio_uart_obj_t *self, mp_float_t timeout) {
+    self->timeout_ms = timeout * 1000;
+}
+
+uint32_t common_hal_busio_uart_rx_characters_available(busio_uart_obj_t *self) {
+    // This assignment is only here because the usart_async routines take a *const argument.
+    // struct usart_async_descriptor * const usart_desc_p = (struct usart_async_descriptor * const) &self->usart_desc;
+    // struct usart_async_status async_status;
+    // usart_async_get_status(usart_desc_p, &async_status);
+    // return async_status.rxcnt;
+    return 0;
+}
+
+void common_hal_busio_uart_clear_rx_buffer(busio_uart_obj_t *self) {
+    // This assignment is only here because the usart_async routines take a *const argument.
+    // struct usart_async_descriptor * const usart_desc_p = (struct usart_async_descriptor * const) &self->usart_desc;
+    // usart_async_flush_rx_buffer(usart_desc_p);
+
+}
+
+// True if there are no characters still to be written.
+bool common_hal_busio_uart_ready_to_tx(busio_uart_obj_t *self) {
+    if (self->tx_pin == NO_PIN) {
+        return false;
+    }
+    return false;
+    // // This assignment is only here because the usart_async routines take a *const argument.
+    // struct usart_async_descriptor * const usart_desc_p = (struct usart_async_descriptor * const) &self->usart_desc;
+    // struct usart_async_status async_status;
+    // usart_async_get_status(usart_desc_p, &async_status);
+    // return !(async_status.flags & USART_ASYNC_STATUS_BUSY);
+}
diff --git a/ports/raspberrypi/common-hal/busio/UART.h b/ports/raspberrypi/common-hal/busio/UART.h
new file mode 100644
index 000000000..43ed9bee0
--- /dev/null
+++ b/ports/raspberrypi/common-hal/busio/UART.h
@@ -0,0 +1,47 @@
+/*
+ * This file is part of the MicroPython project, http://micropython.org/
+ *
+ * The MIT License (MIT)
+ *
+ * Copyright (c) 2021 Scott Shawcroft for Adafruit Industries
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+ * THE SOFTWARE.
+ */
+
+#ifndef MICROPY_INCLUDED_RASPBERRYPI_COMMON_HAL_BUSIO_UART_H
+#define MICROPY_INCLUDED_RASPBERRYPI_COMMON_HAL_BUSIO_UART_H
+
+#include "common-hal/microcontroller/Pin.h"
+
+#include "py/obj.h"
+
+typedef struct {
+    mp_obj_base_t base;
+    // struct usart_async_descriptor usart_desc;
+    uint8_t rx_pin;
+    uint8_t tx_pin;
+    uint8_t character_bits;
+    bool rx_error;
+    uint32_t baudrate;
+    uint32_t timeout_ms;
+    uint32_t buffer_length;
+    uint8_t* buffer;
+} busio_uart_obj_t;
+
+#endif // MICROPY_INCLUDED_RASPBERRYPI_COMMON_HAL_BUSIO_UART_H
diff --git a/ports/raspberrypi/common-hal/busio/__init__.c b/ports/raspberrypi/common-hal/busio/__init__.c
new file mode 100644
index 000000000..41761b674
--- /dev/null
+++ b/ports/raspberrypi/common-hal/busio/__init__.c
@@ -0,0 +1 @@
+// No busio module functions.