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Diffstat (limited to 'shared-bindings/busio/SPI.c')
| -rw-r--r-- | shared-bindings/busio/SPI.c | 304 |
1 files changed, 304 insertions, 0 deletions
diff --git a/shared-bindings/busio/SPI.c b/shared-bindings/busio/SPI.c new file mode 100644 index 000000000..d4d9ec345 --- /dev/null +++ b/shared-bindings/busio/SPI.c @@ -0,0 +1,304 @@ +/* + * This file is part of the MicroPython project, http://micropython.org/ + * + * The MIT License (MIT) + * + * Copyright (c) 2016 Scott Shawcroft + * + * 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. + */ + +// This file contains all of the Python API definitions for the +// busio.SPI class. + +#include <string.h> + +#include "shared-bindings/microcontroller/Pin.h" +#include "shared-bindings/busio/SPI.h" + +#include "lib/utils/context_manager_helpers.h" +#include "py/mperrno.h" +#include "py/nlr.h" +#include "py/runtime.h" + +//| .. currentmodule:: busio +//| +//| :class:`SPI` -- a 3-4 wire serial protocol +//| ----------------------------------------------- +//| +//| SPI is a serial protocol that has exclusive pins for data in and out of the +//| master. It is typically faster than :py:class:`~busio.I2C` because a +//| separate pin is used to control the active slave rather than a transitted +//| address. This class only manages three of the four SPI lines: `!clock`, +//| `!MOSI`, `!MISO`. Its up to the client to manage the appropriate slave +//| select line. (This is common because multiple slaves can share the `!clock`, +//| `!MOSI` and `!MISO` lines and therefore the hardware.) +//| +//| .. class:: SPI(clock, MOSI=None, MISO=None) +//| +//| Construct an SPI object on the given pins. +//| +//| .. seealso:: Using this class directly requires careful lock management. +//| Instead, use :class:`~adafruit_bus_device.spi_device.SPIDevice` to +//| manage locks. +//| +//| .. seealso:: Using this class to directly read registers requires manual +//| bit unpacking. Instead, use an existing driver or make one with +//| :ref:`Register <register-module-reference>` data descriptors. +//| +//| :param ~microcontroller.Pin clock: the pin to use for the clock. +//| :param ~microcontroller.Pin MOSI: the Master Out Slave In pin. +//| :param ~microcontroller.Pin MISO: the Master In Slave Out pin. +//| + +// TODO(tannewt): Support LSB SPI. +STATIC mp_obj_t busio_spi_make_new(const mp_obj_type_t *type, size_t n_args, size_t n_kw, const mp_obj_t *pos_args) { + mp_arg_check_num(n_args, n_kw, 0, MP_OBJ_FUN_ARGS_MAX, true); + busio_spi_obj_t *self = m_new_obj(busio_spi_obj_t); + self->base.type = &busio_spi_type; + mp_map_t kw_args; + mp_map_init_fixed_table(&kw_args, n_kw, pos_args + n_args); + enum { ARG_clock, ARG_MOSI, ARG_MISO }; + static const mp_arg_t allowed_args[] = { + { MP_QSTR_clock, MP_ARG_REQUIRED | MP_ARG_OBJ }, + { MP_QSTR_MOSI, MP_ARG_OBJ, {.u_obj = mp_const_none} }, + { MP_QSTR_MISO, MP_ARG_OBJ, {.u_obj = mp_const_none} }, + }; + mp_arg_val_t args[MP_ARRAY_SIZE(allowed_args)]; + mp_arg_parse_all(n_args, pos_args, &kw_args, MP_ARRAY_SIZE(allowed_args), allowed_args, args); + assert_pin(args[ARG_clock].u_obj, false); + assert_pin(args[ARG_MOSI].u_obj, true); + assert_pin(args[ARG_MISO].u_obj, true); + const mcu_pin_obj_t* clock = MP_OBJ_TO_PTR(args[ARG_clock].u_obj); + assert_pin_free(clock); + const mcu_pin_obj_t* mosi = MP_OBJ_TO_PTR(args[ARG_MOSI].u_obj); + assert_pin_free(mosi); + const mcu_pin_obj_t* miso = MP_OBJ_TO_PTR(args[ARG_MISO].u_obj); + assert_pin_free(miso); + common_hal_busio_spi_construct(self, clock, mosi, miso); + return (mp_obj_t)self; +} + +//| .. method:: SPI.deinit() +//| +//| Turn off the SPI bus. +//| +STATIC mp_obj_t busio_spi_obj_deinit(mp_obj_t self_in) { + busio_spi_obj_t *self = MP_OBJ_TO_PTR(self_in); + common_hal_busio_spi_deinit(self); + return mp_const_none; +} +MP_DEFINE_CONST_FUN_OBJ_1(busio_spi_deinit_obj, busio_spi_obj_deinit); + +//| .. method:: SPI.__enter__() +//| +//| No-op used by Context Managers. +//| +// Provided by context manager helper. + +//| .. method:: SPI.__exit__() +//| +//| Automatically deinitializes the hardware when exiting a context. +//| +STATIC mp_obj_t busio_spi_obj___exit__(size_t n_args, const mp_obj_t *args) { + (void)n_args; + common_hal_busio_spi_deinit(args[0]); + return mp_const_none; +} +STATIC MP_DEFINE_CONST_FUN_OBJ_VAR_BETWEEN(busio_spi_obj___exit___obj, 4, 4, busio_spi_obj___exit__); + +static void check_lock(busio_spi_obj_t *self) { + if (!common_hal_busio_spi_has_lock(self)) { + mp_raise_RuntimeError("Function requires lock"); + } +} + +//| .. method:: SPI.configure(\*, baudrate=100000, polarity=0, phase=0, bits=8) +//| +//| Configures the SPI bus. Only valid when locked. +//| +//| :param int baudrate: the clock rate in Hertz +//| :param int polarity: the base state of the clock line (0 or 1) +//| :param int phase: the edge of the clock that data is captured. First (0) +//| or second (1). Rising or falling depends on clock polarity. +//| :param int bits: the number of bits per word +//| +STATIC mp_obj_t busio_spi_configure(size_t n_args, const mp_obj_t *pos_args, mp_map_t *kw_args) { + enum { ARG_baudrate, ARG_polarity, ARG_phase, ARG_bits }; + static const mp_arg_t allowed_args[] = { + { MP_QSTR_baudrate, MP_ARG_KW_ONLY | MP_ARG_INT, {.u_int = 100000} }, + { MP_QSTR_polarity, MP_ARG_KW_ONLY | MP_ARG_INT, {.u_int = 0} }, + { MP_QSTR_phase, MP_ARG_KW_ONLY | MP_ARG_INT, {.u_int = 0} }, + { MP_QSTR_bits, MP_ARG_KW_ONLY | MP_ARG_INT, {.u_int = 8} }, + }; + busio_spi_obj_t *self = MP_OBJ_TO_PTR(pos_args[0]); + check_lock(self); + mp_arg_val_t args[MP_ARRAY_SIZE(allowed_args)]; + mp_arg_parse_all(n_args - 1, pos_args + 1, kw_args, MP_ARRAY_SIZE(allowed_args), allowed_args, args); + + uint8_t polarity = args[ARG_polarity].u_int; + if (polarity != 0 && polarity != 1) { + mp_raise_ValueError("Invalid polarity"); + } + uint8_t phase = args[ARG_phase].u_int; + if (phase != 0 && phase != 1) { + mp_raise_ValueError("Invalid phase"); + } + uint8_t bits = args[ARG_bits].u_int; + if (bits != 8 && bits != 9) { + mp_raise_ValueError("Invalid number of bits"); + } + + if (!common_hal_busio_spi_configure(self, args[ARG_baudrate].u_int, + polarity, phase, bits)) { + mp_raise_OSError(MP_EIO); + } + return mp_const_none; +} +MP_DEFINE_CONST_FUN_OBJ_KW(busio_spi_configure_obj, 1, busio_spi_configure); + +//| .. method:: SPI.try_lock() +//| +//| Attempts to grab the SPI lock. Returns True on success. +//| +//| :return: True when lock has been grabbed +//| :rtype: bool +//| +STATIC mp_obj_t busio_spi_obj_try_lock(mp_obj_t self_in) { + return mp_obj_new_bool(common_hal_busio_spi_try_lock(MP_OBJ_TO_PTR(self_in))); +} +MP_DEFINE_CONST_FUN_OBJ_1(busio_spi_try_lock_obj, busio_spi_obj_try_lock); + +//| .. method:: SPI.unlock() +//| +//| Releases the SPI lock. +//| +STATIC mp_obj_t busio_spi_obj_unlock(mp_obj_t self_in) { + common_hal_busio_spi_unlock(MP_OBJ_TO_PTR(self_in)); + return mp_const_none; +} +MP_DEFINE_CONST_FUN_OBJ_1(busio_spi_unlock_obj, busio_spi_obj_unlock); + +//| .. method:: SPI.write(buffer, \*, start=0, end=len(buffer)) +//| +//| Write the data contained in ``buf``. Requires the SPI being locked. +//| +//| :param bytearray buffer: buffer containing the bytes to write +//| :param int start: Index to start writing from +//| :param int end: Index to read up to but not include +//| +STATIC mp_obj_t busio_spi_write(size_t n_args, const mp_obj_t *pos_args, mp_map_t *kw_args) { + enum { ARG_buffer, ARG_start, ARG_end }; + static const mp_arg_t allowed_args[] = { + { MP_QSTR_buffer, MP_ARG_REQUIRED | MP_ARG_OBJ, {.u_obj = MP_OBJ_NULL} }, + { MP_QSTR_start, MP_ARG_KW_ONLY | MP_ARG_INT, {.u_int = 0} }, + { MP_QSTR_end, MP_ARG_KW_ONLY | MP_ARG_INT, {.u_int = INT_MAX} }, + }; + busio_spi_obj_t *self = MP_OBJ_TO_PTR(pos_args[0]); + check_lock(self); + mp_arg_val_t args[MP_ARRAY_SIZE(allowed_args)]; + mp_arg_parse_all(n_args - 1, pos_args + 1, kw_args, MP_ARRAY_SIZE(allowed_args), allowed_args, args); + + mp_buffer_info_t bufinfo; + mp_get_buffer_raise(args[ARG_buffer].u_obj, &bufinfo, MP_BUFFER_READ); + int32_t end = args[ARG_end].u_int; + if (end < 0) { + end += bufinfo.len; + } + uint32_t start = args[ARG_start].u_int; + uint32_t len = end - start; + if ((uint32_t) end < start) { + len = 0; + } else if (len > bufinfo.len) { + len = bufinfo.len; + } + + bool ok = common_hal_busio_spi_write(self, ((uint8_t*)bufinfo.buf) + start, len); + if (!ok) { + mp_raise_OSError(MP_EIO); + } + return mp_const_none; +} +MP_DEFINE_CONST_FUN_OBJ_KW(busio_spi_write_obj, 2, busio_spi_write); + + +//| .. method:: SPI.readinto(buffer, \*, start=0, end=len(buffer), write_value=0) +//| +//| Read into the buffer specified by ``buf`` while writing zeroes. Requires the SPI being locked. +//| +//| :param bytearray buffer: buffer to write into +//| :param int start: Index to start writing at +//| :param int end: Index to write up to but not include +//| :param int write_value: Value to write reading. (Usually ignored.) +//| +STATIC mp_obj_t busio_spi_readinto(size_t n_args, const mp_obj_t *pos_args, mp_map_t *kw_args) { + enum { ARG_buffer, ARG_start, ARG_end, ARG_write_value }; + static const mp_arg_t allowed_args[] = { + { MP_QSTR_buffer, MP_ARG_REQUIRED | MP_ARG_OBJ, {.u_obj = MP_OBJ_NULL} }, + { MP_QSTR_start, MP_ARG_KW_ONLY | MP_ARG_INT, {.u_int = 0} }, + { MP_QSTR_end, MP_ARG_KW_ONLY | MP_ARG_INT, {.u_int = INT_MAX} }, + { MP_QSTR_write_value,MP_ARG_KW_ONLY | MP_ARG_INT, {.u_int = 0} }, + }; + busio_spi_obj_t *self = MP_OBJ_TO_PTR(pos_args[0]); + check_lock(self); + mp_arg_val_t args[MP_ARRAY_SIZE(allowed_args)]; + mp_arg_parse_all(n_args - 1, pos_args + 1, kw_args, MP_ARRAY_SIZE(allowed_args), allowed_args, args); + + mp_buffer_info_t bufinfo; + mp_get_buffer_raise(args[ARG_buffer].u_obj, &bufinfo, MP_BUFFER_WRITE); + int32_t end = args[ARG_end].u_int; + if (end < 0) { + end += bufinfo.len; + } + uint32_t start = args[ARG_start].u_int; + uint32_t len = end - start; + if ((uint32_t) end < start) { + len = 0; + } else if (len > bufinfo.len) { + len = bufinfo.len; + } + + bool ok = common_hal_busio_spi_read(self, ((uint8_t*)bufinfo.buf) + start, len, args[ARG_write_value].u_int); + if (!ok) { + mp_raise_OSError(MP_EIO); + } + return mp_const_none; +} +MP_DEFINE_CONST_FUN_OBJ_KW(busio_spi_readinto_obj, 2, busio_spi_readinto); + +STATIC const mp_rom_map_elem_t busio_spi_locals_dict_table[] = { + { MP_ROM_QSTR(MP_QSTR_deinit), MP_ROM_PTR(&busio_spi_deinit_obj) }, + { MP_ROM_QSTR(MP_QSTR___enter__), MP_ROM_PTR(&default___enter___obj) }, + { MP_ROM_QSTR(MP_QSTR___exit__), MP_ROM_PTR(&busio_spi_obj___exit___obj) }, + + { MP_ROM_QSTR(MP_QSTR_configure), MP_ROM_PTR(&busio_spi_configure_obj) }, + { MP_ROM_QSTR(MP_QSTR_try_lock), MP_ROM_PTR(&busio_spi_try_lock_obj) }, + { MP_ROM_QSTR(MP_QSTR_unlock), MP_ROM_PTR(&busio_spi_unlock_obj) }, + + { MP_ROM_QSTR(MP_QSTR_readinto), MP_ROM_PTR(&busio_spi_readinto_obj) }, + { MP_ROM_QSTR(MP_QSTR_write), MP_ROM_PTR(&busio_spi_write_obj) }, +}; +STATIC MP_DEFINE_CONST_DICT(busio_spi_locals_dict, busio_spi_locals_dict_table); + +const mp_obj_type_t busio_spi_type = { + { &mp_type_type }, + .name = MP_QSTR_SPI, + .make_new = busio_spi_make_new, + .locals_dict = (mp_obj_dict_t*)&busio_spi_locals_dict, +}; |