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micropython/ports/stm32/machine_i2c.c

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/*
* This file is part of the MicroPython project, http://micropython.org/
*
* The MIT License (MIT)
*
* Copyright (c) 2016-2018 Damien P. George
*
* 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 <stdio.h>
#include <string.h>
#include "py/runtime.h"
#include "py/mphal.h"
#include "py/mperrno.h"
#include "extmod/machine_i2c.h"
#include "i2c.h"
#include "modmachine.h"
#if MICROPY_HW_ENABLE_HW_I2C
#define I2C_POLL_DEFAULT_TIMEOUT_US (50000) // 50ms
#if defined(STM32F0) || defined(STM32F4) || defined(STM32F7) || defined(STM32H7)
typedef struct _machine_hard_i2c_obj_t {
mp_obj_base_t base;
i2c_t *i2c;
mp_hal_pin_obj_t scl;
mp_hal_pin_obj_t sda;
} machine_hard_i2c_obj_t;
STATIC const machine_hard_i2c_obj_t machine_hard_i2c_obj[MICROPY_HW_MAX_I2C] = {
#if defined(MICROPY_HW_I2C1_SCL)
[0] = {{&machine_hard_i2c_type}, I2C1, MICROPY_HW_I2C1_SCL, MICROPY_HW_I2C1_SDA},
#endif
#if defined(MICROPY_HW_I2C2_SCL)
[1] = {{&machine_hard_i2c_type}, I2C2, MICROPY_HW_I2C2_SCL, MICROPY_HW_I2C2_SDA},
#endif
#if defined(MICROPY_HW_I2C3_SCL)
[2] = {{&machine_hard_i2c_type}, I2C3, MICROPY_HW_I2C3_SCL, MICROPY_HW_I2C3_SDA},
#endif
#if defined(MICROPY_HW_I2C4_SCL)
[3] = {{&machine_hard_i2c_type}, I2C4, MICROPY_HW_I2C4_SCL, MICROPY_HW_I2C4_SDA},
#endif
};
STATIC void machine_hard_i2c_print(const mp_print_t *print, mp_obj_t self_in, mp_print_kind_t kind) {
machine_hard_i2c_obj_t *self = MP_OBJ_TO_PTR(self_in);
#if defined(STM32F4)
uint32_t freq = self->i2c->CR2 & 0x3f;
uint32_t ccr = self->i2c->CCR;
if (ccr & 0x8000) {
// Fast mode, assume duty cycle of 16/9
freq = freq * 40000 / (ccr & 0xfff);
} else {
// Standard mode
freq = freq * 500000 / (ccr & 0xfff);
}
mp_printf(print, "I2C(%u, scl=%q, sda=%q, freq=%u)",
self - &machine_hard_i2c_obj[0] + 1,
mp_hal_pin_name(self->scl), mp_hal_pin_name(self->sda),
freq);
#else
uint32_t timingr = self->i2c->TIMINGR;
uint32_t presc = timingr >> 28;
uint32_t sclh = timingr >> 8 & 0xff;
uint32_t scll = timingr & 0xff;
uint32_t freq = HAL_RCC_GetPCLK1Freq() / (presc + 1) / (sclh + scll + 2);
mp_printf(print, "I2C(%u, scl=%q, sda=%q, freq=%u, timingr=0x%08x)",
self - &machine_hard_i2c_obj[0] + 1,
mp_hal_pin_name(self->scl), mp_hal_pin_name(self->sda),
freq, timingr);
#endif
}
void machine_hard_i2c_init(machine_hard_i2c_obj_t *self, uint32_t freq, uint32_t timeout_us) {
uint32_t timeout_ms = (timeout_us + 999) / 1000;
i2c_init(self->i2c, self->scl, self->sda, freq, timeout_ms);
}
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) {
machine_hard_i2c_obj_t *self = MP_OBJ_TO_PTR(self_in);
size_t remain_len = 0;
for (size_t i = 0; i < n; ++i) {
remain_len += bufs[i].len;
}
int ret = i2c_start_addr(self->i2c, flags & MP_MACHINE_I2C_FLAG_READ, addr, remain_len, flags & MP_MACHINE_I2C_FLAG_STOP);
if (ret < 0) {
return ret;
}
int num_acks = 0; // only valid for write; for read it'll be 0
for (; n--; ++bufs) {
remain_len -= bufs->len;
if (flags & MP_MACHINE_I2C_FLAG_READ) {
ret = i2c_read(self->i2c, bufs->buf, bufs->len, remain_len);
} else {
ret = i2c_write(self->i2c, bufs->buf, bufs->len, remain_len);
}
if (ret < 0) {
return ret;
}
num_acks += ret;
}
return num_acks;
}
#else
// No hardware I2C driver for this MCU so use the software implementation
typedef mp_machine_soft_i2c_obj_t machine_hard_i2c_obj_t;
STATIC machine_hard_i2c_obj_t machine_hard_i2c_obj[MICROPY_HW_MAX_I2C] = {
#if defined(MICROPY_HW_I2C1_SCL)
[0] = {{&machine_hard_i2c_type}, 1, I2C_POLL_DEFAULT_TIMEOUT_US, MICROPY_HW_I2C1_SCL, MICROPY_HW_I2C1_SDA},
#endif
#if defined(MICROPY_HW_I2C2_SCL)
[1] = {{&machine_hard_i2c_type}, 1, I2C_POLL_DEFAULT_TIMEOUT_US, MICROPY_HW_I2C2_SCL, MICROPY_HW_I2C2_SDA},
#endif
#if defined(MICROPY_HW_I2C3_SCL)
[2] = {{&machine_hard_i2c_type}, 1, I2C_POLL_DEFAULT_TIMEOUT_US, MICROPY_HW_I2C3_SCL, MICROPY_HW_I2C3_SDA},
#endif
#if defined(MICROPY_HW_I2C4_SCL)
[3] = {{&machine_hard_i2c_type}, 1, I2C_POLL_DEFAULT_TIMEOUT_US, MICROPY_HW_I2C4_SCL, MICROPY_HW_I2C4_SDA},
#endif
};
STATIC void machine_hard_i2c_print(const mp_print_t *print, mp_obj_t self_in, mp_print_kind_t kind) {
machine_hard_i2c_obj_t *self = MP_OBJ_TO_PTR(self_in);
mp_printf(print, "I2C(%u, scl=%q, sda=%q, freq=%u, timeout=%u)",
self - &machine_hard_i2c_obj[0] + 1,
self->scl->name, self->sda->name, 500000 / self->us_delay, self->us_timeout);
}
STATIC void machine_hard_i2c_init(machine_hard_i2c_obj_t *self, uint32_t freq, uint32_t timeout) {
// set parameters
if (freq >= 1000000) {
// allow fastest possible bit-bang rate
self->us_delay = 0;
} else {
self->us_delay = 500000 / freq;
if (self->us_delay == 0) {
self->us_delay = 1;
}
}
self->us_timeout = timeout;
// init pins
mp_hal_pin_open_drain(self->scl);
mp_hal_pin_open_drain(self->sda);
}
#define machine_hard_i2c_transfer mp_machine_soft_i2c_transfer
#endif
/******************************************************************************/
/* MicroPython bindings for machine API */
#if defined(STM32F0) || defined(STM32F7) || defined(STM32H7)
#define MACHINE_I2C_TIMINGR (1)
#else
#define MACHINE_I2C_TIMINGR (0)
#endif
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) {
MP_MACHINE_I2C_CHECK_FOR_LEGACY_SOFTI2C_CONSTRUCTION(n_args, n_kw, all_args);
// parse args
enum { ARG_id, ARG_scl, ARG_sda, ARG_freq, ARG_timeout, ARG_timingr };
static const mp_arg_t allowed_args[] = {
{ MP_QSTR_id, MP_ARG_REQUIRED | MP_ARG_OBJ },
{ MP_QSTR_scl, MP_ARG_KW_ONLY | MP_ARG_OBJ, {.u_obj = MP_OBJ_NULL} },
{ MP_QSTR_sda, MP_ARG_KW_ONLY | MP_ARG_OBJ, {.u_obj = MP_OBJ_NULL} },
{ MP_QSTR_freq, MP_ARG_KW_ONLY | MP_ARG_INT, {.u_int = 400000} },
{ MP_QSTR_timeout, MP_ARG_KW_ONLY | MP_ARG_INT, {.u_int = I2C_POLL_DEFAULT_TIMEOUT_US} },
#if MACHINE_I2C_TIMINGR
{ MP_QSTR_timingr, MP_ARG_KW_ONLY | MP_ARG_OBJ, {.u_rom_obj = MP_ROM_NONE} },
#endif
};
mp_arg_val_t args[MP_ARRAY_SIZE(allowed_args)];
mp_arg_parse_all_kw_array(n_args, n_kw, all_args, MP_ARRAY_SIZE(allowed_args), allowed_args, args);
// get static peripheral object
int i2c_id = i2c_find_peripheral(args[ARG_id].u_obj);
machine_hard_i2c_obj_t *self = (machine_hard_i2c_obj_t *)&machine_hard_i2c_obj[i2c_id - 1];
// here we would check the scl/sda pins and configure them, but it's not implemented
if (args[ARG_scl].u_obj != MP_OBJ_NULL || args[ARG_sda].u_obj != MP_OBJ_NULL) {
mp_raise_ValueError(MP_ERROR_TEXT("explicit choice of scl/sda is not implemented"));
}
// initialise the I2C peripheral
machine_hard_i2c_init(self, args[ARG_freq].u_int, args[ARG_timeout].u_int);
#if MACHINE_I2C_TIMINGR
// If given, explicitly set the TIMINGR value
if (args[ARG_timingr].u_obj != mp_const_none) {
self->i2c->TIMINGR = mp_obj_get_int_truncated(args[ARG_timingr].u_obj);
}
#endif
return MP_OBJ_FROM_PTR(self);
}
STATIC const mp_machine_i2c_p_t machine_hard_i2c_p = {
.transfer = machine_hard_i2c_transfer,
};
MP_DEFINE_CONST_OBJ_TYPE(
machine_hard_i2c_type,
MP_QSTR_I2C,
MP_TYPE_FLAG_NONE,
make_new, machine_hard_i2c_make_new,
print, machine_hard_i2c_print,
protocol, &machine_hard_i2c_p,
locals_dict, &mp_machine_i2c_locals_dict
);
#endif // MICROPY_HW_ENABLE_HW_I2C
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