c769da1aaa
On MCUs that have an I2C TIMINGR register, this can now be explicitly set via the "timingr" keyword argument to the I2C constructor, for both machine.I2C and pyb.I2C. This allows to configure precise timing values when the defaults are inadequate.
277 lines
9.7 KiB
C
277 lines
9.7 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) 2016-2018 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 <stdio.h>
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#include <string.h>
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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 "i2c.h"
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#if MICROPY_HW_ENABLE_HW_I2C
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STATIC const mp_obj_type_t machine_hard_i2c_type;
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#define I2C_POLL_DEFAULT_TIMEOUT_US (50000) // 50ms
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#if defined(STM32F0) || defined(STM32F4) || defined(STM32F7)
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typedef struct _machine_hard_i2c_obj_t {
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mp_obj_base_t base;
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i2c_t *i2c;
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mp_hal_pin_obj_t scl;
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mp_hal_pin_obj_t sda;
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} machine_hard_i2c_obj_t;
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STATIC const machine_hard_i2c_obj_t machine_hard_i2c_obj[MICROPY_HW_MAX_I2C] = {
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#if defined(MICROPY_HW_I2C1_SCL)
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[0] = {{&machine_hard_i2c_type}, I2C1, MICROPY_HW_I2C1_SCL, MICROPY_HW_I2C1_SDA},
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#endif
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#if defined(MICROPY_HW_I2C2_SCL)
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[1] = {{&machine_hard_i2c_type}, I2C2, MICROPY_HW_I2C2_SCL, MICROPY_HW_I2C2_SDA},
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#endif
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#if defined(MICROPY_HW_I2C3_SCL)
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[2] = {{&machine_hard_i2c_type}, I2C3, MICROPY_HW_I2C3_SCL, MICROPY_HW_I2C3_SDA},
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#endif
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#if defined(MICROPY_HW_I2C4_SCL)
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[3] = {{&machine_hard_i2c_type}, I2C4, MICROPY_HW_I2C4_SCL, MICROPY_HW_I2C4_SDA},
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#endif
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};
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STATIC void machine_hard_i2c_print(const mp_print_t *print, mp_obj_t self_in, mp_print_kind_t kind) {
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machine_hard_i2c_obj_t *self = MP_OBJ_TO_PTR(self_in);
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#if defined(STM32F4)
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uint32_t freq = self->i2c->CR2 & 0x3f;
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uint32_t ccr = self->i2c->CCR;
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if (ccr & 0x8000) {
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// Fast mode, assume duty cycle of 16/9
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freq = freq * 40000 / (ccr & 0xfff);
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} else {
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// Standard mode
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freq = freq * 500000 / (ccr & 0xfff);
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}
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mp_printf(print, "I2C(%u, scl=%q, sda=%q, freq=%u)",
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self - &machine_hard_i2c_obj[0] + 1,
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mp_hal_pin_name(self->scl), mp_hal_pin_name(self->sda),
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freq);
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#else
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uint32_t timingr = self->i2c->TIMINGR;
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uint32_t presc = timingr >> 28;
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uint32_t sclh = timingr >> 8 & 0xff;
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uint32_t scll = timingr & 0xff;
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uint32_t freq = HAL_RCC_GetPCLK1Freq() / (presc + 1) / (sclh + scll + 2);
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mp_printf(print, "I2C(%u, scl=%q, sda=%q, freq=%u, timingr=0x%08x)",
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self - &machine_hard_i2c_obj[0] + 1,
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mp_hal_pin_name(self->scl), mp_hal_pin_name(self->sda),
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freq, timingr);
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#endif
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}
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void machine_hard_i2c_init(machine_hard_i2c_obj_t *self, uint32_t freq, uint32_t timeout_us) {
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uint32_t timeout_ms = (timeout_us + 999) / 1000;
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i2c_init(self->i2c, self->scl, self->sda, freq, timeout_ms);
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}
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int machine_hard_i2c_transfer(mp_obj_base_t *self_in, uint16_t addr, size_t n, mp_machine_i2c_buf_t *bufs, unsigned int flags) {
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machine_hard_i2c_obj_t *self = MP_OBJ_TO_PTR(self_in);
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size_t remain_len = 0;
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for (size_t i = 0; i < n; ++i) {
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remain_len += bufs[i].len;
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}
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int ret = i2c_start_addr(self->i2c, flags & MP_MACHINE_I2C_FLAG_READ, addr, remain_len, flags & MP_MACHINE_I2C_FLAG_STOP);
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if (ret < 0) {
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return ret;
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}
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int num_acks = 0; // only valid for write; for read it'll be 0
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for (; n--; ++bufs) {
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remain_len -= bufs->len;
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if (flags & MP_MACHINE_I2C_FLAG_READ) {
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ret = i2c_read(self->i2c, bufs->buf, bufs->len, remain_len);
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} else {
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ret = i2c_write(self->i2c, bufs->buf, bufs->len, remain_len);
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}
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if (ret < 0) {
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return ret;
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}
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num_acks += ret;
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}
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return num_acks;
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}
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#else
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// No hardware I2C driver for this MCU so use the software implementation
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typedef mp_machine_soft_i2c_obj_t machine_hard_i2c_obj_t;
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STATIC machine_hard_i2c_obj_t machine_hard_i2c_obj[MICROPY_HW_MAX_I2C] = {
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#if defined(MICROPY_HW_I2C1_SCL)
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[0] = {{&machine_hard_i2c_type}, 1, I2C_POLL_DEFAULT_TIMEOUT_US, MICROPY_HW_I2C1_SCL, MICROPY_HW_I2C1_SDA},
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#endif
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#if defined(MICROPY_HW_I2C2_SCL)
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[1] = {{&machine_hard_i2c_type}, 1, I2C_POLL_DEFAULT_TIMEOUT_US, MICROPY_HW_I2C2_SCL, MICROPY_HW_I2C2_SDA},
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#endif
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#if defined(MICROPY_HW_I2C3_SCL)
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[2] = {{&machine_hard_i2c_type}, 1, I2C_POLL_DEFAULT_TIMEOUT_US, MICROPY_HW_I2C3_SCL, MICROPY_HW_I2C3_SDA},
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#endif
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#if defined(MICROPY_HW_I2C4_SCL)
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[3] = {{&machine_hard_i2c_type}, 1, I2C_POLL_DEFAULT_TIMEOUT_US, MICROPY_HW_I2C4_SCL, MICROPY_HW_I2C4_SDA},
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#endif
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};
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STATIC void machine_hard_i2c_print(const mp_print_t *print, mp_obj_t self_in, mp_print_kind_t kind) {
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machine_hard_i2c_obj_t *self = MP_OBJ_TO_PTR(self_in);
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mp_printf(print, "I2C(%u, scl=%q, sda=%q, freq=%u, timeout=%u)",
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self - &machine_hard_i2c_obj[0] + 1,
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self->scl->name, self->sda->name, 500000 / self->us_delay, self->us_timeout);
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}
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STATIC void machine_hard_i2c_init(machine_hard_i2c_obj_t *self, uint32_t freq, uint32_t timeout) {
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// set parameters
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if (freq >= 1000000) {
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// allow fastest possible bit-bang rate
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self->us_delay = 0;
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} else {
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self->us_delay = 500000 / freq;
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if (self->us_delay == 0) {
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self->us_delay = 1;
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}
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}
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self->us_timeout = timeout;
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// init pins
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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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}
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#define machine_hard_i2c_transfer mp_machine_soft_i2c_transfer
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#endif
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/******************************************************************************/
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/* MicroPython bindings for machine API */
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#if defined(STM32F0) || defined(STM32F7)
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#define MACHINE_I2C_TIMINGR (1)
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#else
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#define MACHINE_I2C_TIMINGR (0)
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#endif
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mp_obj_t machine_hard_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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// parse args
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enum { ARG_id, ARG_scl, ARG_sda, ARG_freq, ARG_timeout, ARG_timingr };
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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_scl, MP_ARG_KW_ONLY | MP_ARG_OBJ, {.u_obj = MP_OBJ_NULL} },
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{ MP_QSTR_sda, MP_ARG_KW_ONLY | MP_ARG_OBJ, {.u_obj = MP_OBJ_NULL} },
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{ MP_QSTR_freq, MP_ARG_KW_ONLY | MP_ARG_INT, {.u_int = 400000} },
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{ MP_QSTR_timeout, MP_ARG_KW_ONLY | MP_ARG_INT, {.u_int = I2C_POLL_DEFAULT_TIMEOUT_US} },
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#if MACHINE_I2C_TIMINGR
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{ MP_QSTR_timingr, MP_ARG_KW_ONLY | MP_ARG_OBJ, {.u_obj = mp_const_none} },
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#endif
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};
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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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// work out i2c bus
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int i2c_id = 0;
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if (mp_obj_is_str(args[ARG_id].u_obj)) {
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const char *port = mp_obj_str_get_str(args[ARG_id].u_obj);
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if (0) {
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#ifdef MICROPY_HW_I2C1_NAME
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} else if (strcmp(port, MICROPY_HW_I2C1_NAME) == 0) {
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i2c_id = 1;
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#endif
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#ifdef MICROPY_HW_I2C2_NAME
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} else if (strcmp(port, MICROPY_HW_I2C2_NAME) == 0) {
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i2c_id = 2;
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#endif
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#ifdef MICROPY_HW_I2C3_NAME
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} else if (strcmp(port, MICROPY_HW_I2C3_NAME) == 0) {
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i2c_id = 3;
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#endif
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} else {
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nlr_raise(mp_obj_new_exception_msg_varg(&mp_type_ValueError,
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"I2C(%s) doesn't exist", port));
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}
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} else {
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i2c_id = mp_obj_get_int(args[ARG_id].u_obj);
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if (i2c_id < 1 || i2c_id > MP_ARRAY_SIZE(machine_hard_i2c_obj)
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|| machine_hard_i2c_obj[i2c_id - 1].base.type == NULL) {
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nlr_raise(mp_obj_new_exception_msg_varg(&mp_type_ValueError,
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"I2C(%d) doesn't exist", i2c_id));
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}
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}
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// get static peripheral object
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machine_hard_i2c_obj_t *self = (machine_hard_i2c_obj_t*)&machine_hard_i2c_obj[i2c_id - 1];
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// here we would check the scl/sda pins and configure them, but it's not implemented
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if (args[ARG_scl].u_obj != MP_OBJ_NULL || args[ARG_sda].u_obj != MP_OBJ_NULL) {
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mp_raise_ValueError("explicit choice of scl/sda is not implemented");
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}
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// initialise the I2C peripheral
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machine_hard_i2c_init(self, args[ARG_freq].u_int, args[ARG_timeout].u_int);
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#if MACHINE_I2C_TIMINGR
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// If given, explicitly set the TIMINGR value
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if (args[ARG_timingr].u_obj != mp_const_none) {
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self->i2c->TIMINGR = mp_obj_get_int_truncated(args[ARG_timingr].u_obj);
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}
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#endif
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return MP_OBJ_FROM_PTR(self);
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}
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STATIC const mp_machine_i2c_p_t machine_hard_i2c_p = {
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.transfer = machine_hard_i2c_transfer,
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};
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STATIC const mp_obj_type_t machine_hard_i2c_type = {
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{ &mp_type_type },
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.name = MP_QSTR_I2C,
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.print = machine_hard_i2c_print,
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.make_new = machine_hard_i2c_make_new,
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.protocol = &machine_hard_i2c_p,
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.locals_dict = (mp_obj_dict_t*)&mp_machine_soft_i2c_locals_dict,
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};
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#endif // MICROPY_HW_ENABLE_HW_I2C
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