/* * 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.I2C class. #include "shared-bindings/microcontroller/Pin.h" #include "shared-bindings/busio/I2C.h" #include "shared-bindings/util.h" #include "lib/utils/buffer_helper.h" #include "lib/utils/context_manager_helpers.h" #include "py/runtime.h" #include "supervisor/shared/translate.h" //| .. currentmodule:: busio //| //| :class:`I2C` --- Two wire serial protocol //| ------------------------------------------ //| //| .. class:: I2C(scl, sda, *, frequency=400000, timeout=255) //| //| I2C is a two-wire protocol for communicating between devices. At the //| physical level it consists of 2 wires: SCL and SDA, the clock and data //| lines respectively. //| //| .. seealso:: Using this class directly requires careful lock management. //| Instead, use :class:`~adafruit_bus_device.i2c_device.I2CDevice` 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 ` data descriptors. //| //| :param ~microcontroller.Pin scl: The clock pin //| :param ~microcontroller.Pin sda: The data pin //| :param int frequency: The clock frequency in Hertz //| :param int timeout: The maximum clock stretching timeut - (used only for bitbangio.I2C; ignored for busio.I2C) //| STATIC mp_obj_t busio_i2c_make_new(const mp_obj_type_t *type, size_t n_args, const mp_obj_t *pos_args, mp_map_t *kw_args) { busio_i2c_obj_t *self = m_new_obj(busio_i2c_obj_t); self->base.type = &busio_i2c_type; enum { ARG_scl, ARG_sda, ARG_frequency, ARG_timeout }; static const mp_arg_t allowed_args[] = { { MP_QSTR_scl, MP_ARG_REQUIRED | MP_ARG_OBJ }, { MP_QSTR_sda, MP_ARG_REQUIRED | MP_ARG_OBJ }, { MP_QSTR_frequency, MP_ARG_KW_ONLY | MP_ARG_INT, {.u_int = 400000} }, { MP_QSTR_timeout, MP_ARG_KW_ONLY | MP_ARG_INT, {.u_int = 255} }, }; 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_scl].u_obj, false); assert_pin(args[ARG_sda].u_obj, false); const mcu_pin_obj_t* scl = MP_OBJ_TO_PTR(args[ARG_scl].u_obj); assert_pin_free(scl); const mcu_pin_obj_t* sda = MP_OBJ_TO_PTR(args[ARG_sda].u_obj); assert_pin_free(sda); common_hal_busio_i2c_construct(self, scl, sda, args[ARG_frequency].u_int, args[ARG_timeout].u_int); return (mp_obj_t)self; } //| .. method:: deinit() //| //| Releases control of the underlying hardware so other classes can use it. //| STATIC mp_obj_t busio_i2c_obj_deinit(mp_obj_t self_in) { busio_i2c_obj_t *self = MP_OBJ_TO_PTR(self_in); common_hal_busio_i2c_deinit(self); return mp_const_none; } MP_DEFINE_CONST_FUN_OBJ_1(busio_i2c_deinit_obj, busio_i2c_obj_deinit); STATIC void check_for_deinit(busio_i2c_obj_t *self) { if (common_hal_busio_i2c_deinited(self)) { raise_deinited_error(); } } //| .. method:: __enter__() //| //| No-op used in Context Managers. //| // Provided by context manager helper. //| .. method:: __exit__() //| //| Automatically deinitializes the hardware on context exit. See //| :ref:`lifetime-and-contextmanagers` for more info. //| STATIC mp_obj_t busio_i2c_obj___exit__(size_t n_args, const mp_obj_t *args) { (void)n_args; common_hal_busio_i2c_deinit(args[0]); return mp_const_none; } STATIC MP_DEFINE_CONST_FUN_OBJ_VAR_BETWEEN(busio_i2c___exit___obj, 4, 4, busio_i2c_obj___exit__); static void check_lock(busio_i2c_obj_t *self) { asm(""); if (!common_hal_busio_i2c_has_lock(self)) { mp_raise_RuntimeError(translate("Function requires lock")); } } //| .. method:: scan() //| //| Scan all I2C addresses between 0x08 and 0x77 inclusive and return a //| list of those that respond. //| //| :return: List of device ids on the I2C bus //| :rtype: list //| STATIC mp_obj_t busio_i2c_scan(mp_obj_t self_in) { busio_i2c_obj_t *self = MP_OBJ_TO_PTR(self_in); check_for_deinit(self); check_lock(self); mp_obj_t list = mp_obj_new_list(0, NULL); // 7-bit addresses 0b0000xxx and 0b1111xxx are reserved for (int addr = 0x08; addr < 0x78; ++addr) { bool success = common_hal_busio_i2c_probe(self, addr); if (success) { mp_obj_list_append(list, MP_OBJ_NEW_SMALL_INT(addr)); } } return list; } MP_DEFINE_CONST_FUN_OBJ_1(busio_i2c_scan_obj, busio_i2c_scan); //| .. method:: try_lock() //| //| Attempts to grab the I2C lock. Returns True on success. //| //| :return: True when lock has been grabbed //| :rtype: bool //| STATIC mp_obj_t busio_i2c_obj_try_lock(mp_obj_t self_in) { busio_i2c_obj_t *self = MP_OBJ_TO_PTR(self_in); check_for_deinit(self); return mp_obj_new_bool(common_hal_busio_i2c_try_lock(self)); } MP_DEFINE_CONST_FUN_OBJ_1(busio_i2c_try_lock_obj, busio_i2c_obj_try_lock); //| .. method:: unlock() //| //| Releases the I2C lock. //| STATIC mp_obj_t busio_i2c_obj_unlock(mp_obj_t self_in) { busio_i2c_obj_t *self = MP_OBJ_TO_PTR(self_in); check_for_deinit(self); common_hal_busio_i2c_unlock(self); return mp_const_none; } MP_DEFINE_CONST_FUN_OBJ_1(busio_i2c_unlock_obj, busio_i2c_obj_unlock); //| .. method:: readfrom_into(address, buffer, *, start=0, end=None) //| //| Read into ``buffer`` from the slave specified by ``address``. //| The number of bytes read will be the length of ``buffer``. //| At least one byte must be read. //| //| If ``start`` or ``end`` is provided, then the buffer will be sliced //| as if ``buffer[start:end]``. This will not cause an allocation like //| ``buf[start:end]`` will so it saves memory. //| //| :param int address: 7-bit device address //| :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. Defaults to ``len(buffer)`` //| // Shared arg parsing for readfrom_into and writeto_then_readfrom. STATIC void readfrom(busio_i2c_obj_t *self, mp_int_t address, mp_obj_t buffer, int32_t start, mp_int_t end) { mp_buffer_info_t bufinfo; mp_get_buffer_raise(buffer, &bufinfo, MP_BUFFER_WRITE); size_t length = bufinfo.len; normalize_buffer_bounds(&start, end, &length); if (length == 0) { mp_raise_ValueError(translate("Buffer must be at least length 1")); } uint8_t status = common_hal_busio_i2c_read(self, address, ((uint8_t*)bufinfo.buf) + start, length); if (status != 0) { mp_raise_OSError(status); } } STATIC mp_obj_t busio_i2c_readfrom_into(size_t n_args, const mp_obj_t *pos_args, mp_map_t *kw_args) { enum { ARG_address, ARG_buffer, ARG_start, ARG_end }; static const mp_arg_t allowed_args[] = { { MP_QSTR_address, MP_ARG_REQUIRED | MP_ARG_INT, {.u_int = 0} }, { 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_i2c_obj_t *self = MP_OBJ_TO_PTR(pos_args[0]); check_for_deinit(self); 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); readfrom(self, args[ARG_address].u_int, args[ARG_buffer].u_obj, args[ARG_start].u_int, args[ARG_end].u_int); return mp_const_none; } MP_DEFINE_CONST_FUN_OBJ_KW(busio_i2c_readfrom_into_obj, 3, busio_i2c_readfrom_into); //| .. method:: writeto(address, buffer, *, start=0, end=None, stop=True) //| //| Write the bytes from ``buffer`` to the slave specified by ``address``. //| Transmits a stop bit when stop is True. Setting stop=False is deprecated and stop will be //| removed in CircuitPython 6.x. Use `writeto_then_readfrom` when needing a write, no stop and //| repeated start before a read. //| //| If ``start`` or ``end`` is provided, then the buffer will be sliced //| as if ``buffer[start:end]``. This will not cause an allocation like //| ``buffer[start:end]`` will so it saves memory. //| //| Writing a buffer or slice of length zero is permitted, as it can be used //| to poll for the existence of a device. //| //| :param int address: 7-bit device address //| :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. Defaults to ``len(buffer)`` //| :param bool stop: If true, output an I2C stop condition after the buffer is written. //| Deprecated. Will be removed in 6.x and act as stop=True. //| // Shared arg parsing for writeto and writeto_then_readfrom. STATIC void writeto(busio_i2c_obj_t *self, mp_int_t address, mp_obj_t buffer, int32_t start, mp_int_t end, bool stop) { // get the buffer to write the data from mp_buffer_info_t bufinfo; mp_get_buffer_raise(buffer, &bufinfo, MP_BUFFER_READ); size_t length = bufinfo.len; normalize_buffer_bounds(&start, end, &length); // do the transfer uint8_t status = common_hal_busio_i2c_write(self, address, ((uint8_t*) bufinfo.buf) + start, length, stop); if (status != 0) { mp_raise_OSError(status); } } STATIC mp_obj_t busio_i2c_writeto(size_t n_args, const mp_obj_t *pos_args, mp_map_t *kw_args) { enum { ARG_address, ARG_buffer, ARG_start, ARG_end, ARG_stop }; static const mp_arg_t allowed_args[] = { { MP_QSTR_address, MP_ARG_REQUIRED | MP_ARG_INT, {.u_int = 0} }, { 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_stop, MP_ARG_KW_ONLY | MP_ARG_BOOL, {.u_bool = true} }, }; busio_i2c_obj_t *self = MP_OBJ_TO_PTR(pos_args[0]); check_for_deinit(self); 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); writeto(self, args[ARG_address].u_int, args[ARG_buffer].u_obj, args[ARG_start].u_int, args[ARG_end].u_int, args[ARG_stop].u_bool); return mp_const_none; } STATIC MP_DEFINE_CONST_FUN_OBJ_KW(busio_i2c_writeto_obj, 1, busio_i2c_writeto); //| .. method:: writeto_then_readfrom(address, out_buffer, in_buffer, *, out_start=0, out_end=None, in_start=0, in_end=None) //| //| Write the bytes from ``out_buffer`` to the slave specified by ``address``, generate no stop //| bit, generate a repeated start and read into ``in_buffer``. ``out_buffer`` and //| ``in_buffer`` can be the same buffer because they are used sequentially. //| //| If ``start`` or ``end`` is provided, then the corresponding buffer will be sliced //| as if ``buffer[start:end]``. This will not cause an allocation like ``buf[start:end]`` //| will so it saves memory. //| //| :param int address: 7-bit device address //| :param bytearray out_buffer: buffer containing the bytes to write //| :param bytearray in_buffer: buffer to write into //| :param int out_start: Index to start writing from //| :param int out_end: Index to read up to but not include. Defaults to ``len(buffer)`` //| :param int in_start: Index to start writing at //| :param int in_end: Index to write up to but not include. Defaults to ``len(buffer)`` //| STATIC mp_obj_t busio_i2c_writeto_then_readfrom(size_t n_args, const mp_obj_t *pos_args, mp_map_t *kw_args) { enum { ARG_address, ARG_out_buffer, ARG_in_buffer, ARG_out_start, ARG_out_end, ARG_in_start, ARG_in_end }; static const mp_arg_t allowed_args[] = { { MP_QSTR_address, MP_ARG_REQUIRED | MP_ARG_INT, {.u_int = 0} }, { MP_QSTR_out_buffer, MP_ARG_REQUIRED | MP_ARG_OBJ, {.u_obj = MP_OBJ_NULL} }, { MP_QSTR_in_buffer, MP_ARG_REQUIRED | MP_ARG_OBJ, {.u_obj = MP_OBJ_NULL} }, { MP_QSTR_out_start, MP_ARG_KW_ONLY | MP_ARG_INT, {.u_int = 0} }, { MP_QSTR_out_end, MP_ARG_KW_ONLY | MP_ARG_INT, {.u_int = INT_MAX} }, { MP_QSTR_in_start, MP_ARG_KW_ONLY | MP_ARG_INT, {.u_int = 0} }, { MP_QSTR_in_end, MP_ARG_KW_ONLY | MP_ARG_INT, {.u_int = INT_MAX} }, }; busio_i2c_obj_t *self = MP_OBJ_TO_PTR(pos_args[0]); check_for_deinit(self); 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); writeto(self, args[ARG_address].u_int, args[ARG_out_buffer].u_obj, args[ARG_out_start].u_int, args[ARG_out_end].u_int, false); readfrom(self, args[ARG_address].u_int, args[ARG_in_buffer].u_obj, args[ARG_in_start].u_int, args[ARG_in_end].u_int); return mp_const_none; } MP_DEFINE_CONST_FUN_OBJ_KW(busio_i2c_writeto_then_readfrom_obj, 3, busio_i2c_writeto_then_readfrom); STATIC const mp_rom_map_elem_t busio_i2c_locals_dict_table[] = { { MP_ROM_QSTR(MP_QSTR_deinit), MP_ROM_PTR(&busio_i2c_deinit_obj) }, { MP_ROM_QSTR(MP_QSTR___enter__), MP_ROM_PTR(&default___enter___obj) }, { MP_ROM_QSTR(MP_QSTR___exit__), MP_ROM_PTR(&busio_i2c___exit___obj) }, { MP_ROM_QSTR(MP_QSTR_scan), MP_ROM_PTR(&busio_i2c_scan_obj) }, { MP_ROM_QSTR(MP_QSTR_try_lock), MP_ROM_PTR(&busio_i2c_try_lock_obj) }, { MP_ROM_QSTR(MP_QSTR_unlock), MP_ROM_PTR(&busio_i2c_unlock_obj) }, { MP_ROM_QSTR(MP_QSTR_readfrom_into), MP_ROM_PTR(&busio_i2c_readfrom_into_obj) }, { MP_ROM_QSTR(MP_QSTR_writeto), MP_ROM_PTR(&busio_i2c_writeto_obj) }, { MP_ROM_QSTR(MP_QSTR_writeto_then_readfrom), MP_ROM_PTR(&busio_i2c_writeto_then_readfrom_obj) }, }; STATIC MP_DEFINE_CONST_DICT(busio_i2c_locals_dict, busio_i2c_locals_dict_table); const mp_obj_type_t busio_i2c_type = { { &mp_type_type }, .name = MP_QSTR_I2C, .make_new = busio_i2c_make_new, .locals_dict = (mp_obj_dict_t*)&busio_i2c_locals_dict, };