188 lines
6.7 KiB
C
188 lines
6.7 KiB
C
/*
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* This file is part of the MicroPython project, http://micropython.org/
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*
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* The MIT License (MIT)
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*
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* Copyright (c) 2020-2021 Damien P. George
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*
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* Permission is hereby granted, free of charge, to any person obtaining a copy
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* of this software and associated documentation files (the "Software"), to deal
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* in the Software without restriction, including without limitation the rights
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* to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
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* copies of the Software, and to permit persons to whom the Software is
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* furnished to do so, subject to the following conditions:
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*
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* The above copyright notice and this permission notice shall be included in
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* all copies or substantial portions of the Software.
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*
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* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
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* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
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* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
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* AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
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* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
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* OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
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* THE SOFTWARE.
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*/
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#include "py/runtime.h"
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#include "py/mphal.h"
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#include "py/mperrno.h"
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#include "extmod/machine_i2c.h"
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#include "modmachine.h"
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#include "hardware/i2c.h"
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#define DEFAULT_I2C_FREQ (400000)
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#ifndef MICROPY_HW_I2C0_SCL
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#if PICO_DEFAULT_I2C == 0
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#define MICROPY_HW_I2C0_SCL (PICO_DEFAULT_I2C_SCL_PIN)
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#define MICROPY_HW_I2C0_SDA (PICO_DEFAULT_I2C_SDA_PIN)
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#else
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#define MICROPY_HW_I2C0_SCL (9)
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#define MICROPY_HW_I2C0_SDA (8)
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#endif
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#endif
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#ifndef MICROPY_HW_I2C1_SCL
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#if PICO_DEFAULT_I2C == 1
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#define MICROPY_HW_I2C1_SCL (PICO_DEFAULT_I2C_SCL_PIN)
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#define MICROPY_HW_I2C1_SDA (PICO_DEFAULT_I2C_SDA_PIN)
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#else
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#define MICROPY_HW_I2C1_SCL (7)
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#define MICROPY_HW_I2C1_SDA (6)
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#endif
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#endif
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// SDA/SCL on even/odd pins, I2C0/I2C1 on even/odd pairs of pins.
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#define IS_VALID_SCL(i2c, pin) (((pin) & 1) == 1 && (((pin) & 2) >> 1) == (i2c))
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#define IS_VALID_SDA(i2c, pin) (((pin) & 1) == 0 && (((pin) & 2) >> 1) == (i2c))
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typedef struct _machine_i2c_obj_t {
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mp_obj_base_t base;
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i2c_inst_t *const i2c_inst;
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uint8_t i2c_id;
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uint8_t scl;
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uint8_t sda;
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uint32_t freq;
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} machine_i2c_obj_t;
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STATIC machine_i2c_obj_t machine_i2c_obj[] = {
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{{&machine_i2c_type}, i2c0, 0, MICROPY_HW_I2C0_SCL, MICROPY_HW_I2C0_SDA, 0},
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{{&machine_i2c_type}, i2c1, 1, MICROPY_HW_I2C1_SCL, MICROPY_HW_I2C1_SDA, 0},
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};
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STATIC void machine_i2c_print(const mp_print_t *print, mp_obj_t self_in, mp_print_kind_t kind) {
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machine_i2c_obj_t *self = MP_OBJ_TO_PTR(self_in);
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mp_printf(print, "I2C(%u, freq=%u, scl=%u, sda=%u)",
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self->i2c_id, self->freq, self->scl, self->sda);
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}
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mp_obj_t machine_i2c_make_new(const mp_obj_type_t *type, size_t n_args, size_t n_kw, const mp_obj_t *all_args) {
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enum { ARG_id, ARG_freq, ARG_scl, ARG_sda };
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static const mp_arg_t allowed_args[] = {
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{ MP_QSTR_id, MP_ARG_REQUIRED | MP_ARG_OBJ },
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{ MP_QSTR_freq, MP_ARG_INT, {.u_int = DEFAULT_I2C_FREQ} },
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{ MP_QSTR_scl, MP_ARG_KW_ONLY | MP_ARG_OBJ, {.u_rom_obj = MP_ROM_NONE} },
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{ MP_QSTR_sda, MP_ARG_KW_ONLY | MP_ARG_OBJ, {.u_rom_obj = MP_ROM_NONE} },
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};
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// Parse args.
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mp_arg_val_t args[MP_ARRAY_SIZE(allowed_args)];
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mp_arg_parse_all_kw_array(n_args, n_kw, all_args, MP_ARRAY_SIZE(allowed_args), allowed_args, args);
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// Get I2C bus.
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int i2c_id = mp_obj_get_int(args[ARG_id].u_obj);
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if (i2c_id < 0 || i2c_id >= MP_ARRAY_SIZE(machine_i2c_obj)) {
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mp_raise_msg_varg(&mp_type_ValueError, MP_ERROR_TEXT("I2C(%d) doesn't exist"), i2c_id);
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}
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// Get static peripheral object.
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machine_i2c_obj_t *self = (machine_i2c_obj_t *)&machine_i2c_obj[i2c_id];
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// Set SCL/SDA pins if configured.
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if (args[ARG_scl].u_obj != mp_const_none) {
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int scl = mp_hal_get_pin_obj(args[ARG_scl].u_obj);
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if (!IS_VALID_SCL(self->i2c_id, scl)) {
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mp_raise_ValueError(MP_ERROR_TEXT("bad SCL pin"));
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}
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self->scl = scl;
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}
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if (args[ARG_sda].u_obj != mp_const_none) {
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int sda = mp_hal_get_pin_obj(args[ARG_sda].u_obj);
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if (!IS_VALID_SDA(self->i2c_id, sda)) {
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mp_raise_ValueError(MP_ERROR_TEXT("bad SDA pin"));
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}
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self->sda = sda;
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}
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// Initialise the I2C peripheral if any arguments given, or it was not initialised previously.
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if (n_args > 1 || n_kw > 0 || self->freq == 0) {
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self->freq = args[ARG_freq].u_int;
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i2c_init(self->i2c_inst, self->freq);
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self->freq = i2c_set_baudrate(self->i2c_inst, self->freq);
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gpio_set_function(self->scl, GPIO_FUNC_I2C);
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gpio_set_function(self->sda, GPIO_FUNC_I2C);
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gpio_set_pulls(self->scl, true, 0);
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gpio_set_pulls(self->sda, true, 0);
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}
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return MP_OBJ_FROM_PTR(self);
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}
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STATIC int machine_i2c_transfer_single(mp_obj_base_t *self_in, uint16_t addr, size_t len, uint8_t *buf, unsigned int flags) {
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machine_i2c_obj_t *self = (machine_i2c_obj_t *)self_in;
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int ret;
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bool nostop = !(flags & MP_MACHINE_I2C_FLAG_STOP);
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if (flags & MP_MACHINE_I2C_FLAG_READ) {
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ret = i2c_read_blocking(self->i2c_inst, addr, buf, len, nostop);
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} else {
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if (len == 0) {
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// Workaround issue with hardware I2C not accepting zero-length writes.
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mp_machine_soft_i2c_obj_t soft_i2c = {
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.base = { &mp_machine_soft_i2c_type },
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.us_delay = 500000 / self->freq + 1,
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.us_timeout = 50000,
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.scl = self->scl,
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.sda = self->sda,
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};
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mp_machine_i2c_buf_t bufs = {
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.len = len,
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.buf = buf,
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};
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mp_hal_pin_open_drain(self->scl);
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mp_hal_pin_open_drain(self->sda);
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ret = mp_machine_soft_i2c_transfer(&soft_i2c.base, addr, 1, &bufs, flags);
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gpio_set_function(self->scl, GPIO_FUNC_I2C);
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gpio_set_function(self->sda, GPIO_FUNC_I2C);
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return ret;
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} else {
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ret = i2c_write_blocking(self->i2c_inst, addr, buf, len, nostop);
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}
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}
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if (ret < 0) {
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if (ret == PICO_ERROR_TIMEOUT) {
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return -MP_ETIMEDOUT;
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} else {
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return -MP_EIO;
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}
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} else {
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return ret;
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}
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}
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STATIC const mp_machine_i2c_p_t machine_i2c_p = {
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.transfer = mp_machine_i2c_transfer_adaptor,
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.transfer_single = machine_i2c_transfer_single,
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};
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MP_DEFINE_CONST_OBJ_TYPE(
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machine_i2c_type,
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MP_QSTR_I2C,
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MP_TYPE_FLAG_NONE,
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make_new, machine_i2c_make_new,
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print, machine_i2c_print,
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protocol, &machine_i2c_p,
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locals_dict, &mp_machine_i2c_locals_dict
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);
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