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micropython/stmhal/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 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 "genhdr/pins.h"
#include "i2c.h"
STATIC const mp_obj_type_t machine_hard_i2c_type;
#if defined(MCU_SERIES_F4)
// F4xx specific driver for I2C hardware peripheral
// The hardware-specific I2C code below is based heavily on the code from
// V1.5.2 of the STM32 CUBE F4 HAL. Its copyright notice is given here.
/*
* COPYRIGHT(c) 2016 STMicroelectronics
*
* Redistribution and use in source and binary forms, with or without modification,
* are permitted provided that the following conditions are met:
* 1. Redistributions of source code must retain the above copyright notice,
* this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright notice,
* this list of conditions and the following disclaimer in the documentation
* and/or other materials provided with the distribution.
* 3. Neither the name of STMicroelectronics nor the names of its contributors
* may be used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
* AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
* DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
* SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
* CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
* OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
* OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
typedef struct _machine_hard_i2c_obj_t {
mp_obj_base_t base;
const pyb_i2c_obj_t *pyb;
uint32_t *timeout;
} machine_hard_i2c_obj_t;
STATIC uint32_t machine_hard_i2c_timeout[4];
STATIC const machine_hard_i2c_obj_t machine_hard_i2c_obj[] = {
{{&machine_hard_i2c_type}, &pyb_i2c_obj[0], &machine_hard_i2c_timeout[0]},
{{&machine_hard_i2c_type}, &pyb_i2c_obj[1], &machine_hard_i2c_timeout[1]},
{{&machine_hard_i2c_type}, &pyb_i2c_obj[2], &machine_hard_i2c_timeout[2]},
{{&machine_hard_i2c_type}, &pyb_i2c_obj[3], &machine_hard_i2c_timeout[3]},
};
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, freq=%u, timeout=%u)",
self - &machine_hard_i2c_obj[0] + 1,
i2c_get_baudrate(&self->pyb->i2c->Init),
*self->timeout);
}
STATIC void machine_hard_i2c_init(const machine_hard_i2c_obj_t *self, uint32_t freq, uint32_t timeout) {
*self->timeout = timeout;
i2c_init_freq(self->pyb, freq);
}
// this function is based on STM code
STATIC bool I2C_IsAcknowledgeFailed(I2C_HandleTypeDef *hi2c) {
if (__HAL_I2C_GET_FLAG(hi2c, I2C_FLAG_AF) == SET) {
/* Clear NACKF Flag */
__HAL_I2C_CLEAR_FLAG(hi2c, I2C_FLAG_AF);
return true;
}
return false;
}
// this function is based on STM code
STATIC bool I2C_WaitOnFlagUntilTimeout(I2C_HandleTypeDef *hi2c, uint32_t Flag, FlagStatus Status, uint32_t Timeout, uint32_t Tickstart) {
/* Wait until flag is set */
while ((__HAL_I2C_GET_FLAG(hi2c, Flag) ? SET : RESET) == Status) {
if (Timeout != HAL_MAX_DELAY) {
if ((Timeout == 0U)||((HAL_GetTick() - Tickstart ) > Timeout)) {
return false;
}
}
}
return true;
}
// this function is based on STM code
STATIC int I2C_WaitOnRXNEFlagUntilTimeout(I2C_HandleTypeDef *hi2c, uint32_t Timeout, uint32_t Tickstart) {
while (__HAL_I2C_GET_FLAG(hi2c, I2C_FLAG_RXNE) == RESET) {
/* Check if a STOPF is detected */
if (__HAL_I2C_GET_FLAG(hi2c, I2C_FLAG_STOPF) == SET) {
/* Clear STOP Flag */
__HAL_I2C_CLEAR_FLAG(hi2c, I2C_FLAG_STOPF);
return -MP_EBUSY;
}
/* Check for the Timeout */
if ((Timeout == 0U) || ((HAL_GetTick()-Tickstart) > Timeout)) {
return -MP_ETIMEDOUT;
}
}
return 0;
}
// this function is based on STM code
STATIC int send_addr_byte(I2C_HandleTypeDef *hi2c, uint8_t addr_byte, uint32_t Timeout, uint32_t Tickstart) {
/* Generate Start */
hi2c->Instance->CR1 |= I2C_CR1_START;
/* Wait until SB flag is set */
if (!I2C_WaitOnFlagUntilTimeout(hi2c, I2C_FLAG_SB, RESET, Timeout, Tickstart)) {
return -MP_ETIMEDOUT;
}
/* Send slave address */
hi2c->Instance->DR = addr_byte;
/* Wait until ADDR flag is set */
while (__HAL_I2C_GET_FLAG(hi2c, I2C_FLAG_ADDR) == RESET) {
if (__HAL_I2C_GET_FLAG(hi2c, I2C_FLAG_AF) == SET) {
// nack received for addr, release the bus cleanly
hi2c->Instance->CR1 |= I2C_CR1_STOP;
__HAL_I2C_CLEAR_FLAG(hi2c, I2C_FLAG_AF);
return -MP_ENODEV;
}
/* Check for the Timeout */
if (Timeout != HAL_MAX_DELAY) {
if ((Timeout == 0U)||((HAL_GetTick() - Tickstart ) > Timeout)) {
return -MP_ETIMEDOUT;
}
}
}
return 0;
}
// this function is based on STM code
int machine_hard_i2c_readfrom(mp_obj_base_t *self_in, uint16_t addr, uint8_t *dest, size_t len, bool stop) {
machine_hard_i2c_obj_t *self = (machine_hard_i2c_obj_t*)self_in;
I2C_HandleTypeDef *hi2c = self->pyb->i2c;
uint32_t Timeout = *self->timeout;
/* Init tickstart for timeout management*/
uint32_t tickstart = HAL_GetTick();
#if 0
// TODO: for multi-master, here we could wait for the bus to be free
// we'd need a flag to tell if we were in the middle of a set of transactions
// (ie didn't send a stop bit in the last call)
/* Wait until BUSY flag is reset */
if (!I2C_WaitOnFlagUntilTimeout(hi2c, I2C_FLAG_BUSY, SET, I2C_TIMEOUT_BUSY_FLAG, tickstart)) {
return -MP_EBUSY;
}
#endif
/* Check if the I2C is already enabled */
if ((hi2c->Instance->CR1 & I2C_CR1_PE) != I2C_CR1_PE) {
/* Enable I2C peripheral */
__HAL_I2C_ENABLE(hi2c);
}
/* Disable Pos */
hi2c->Instance->CR1 &= ~I2C_CR1_POS;
/* Enable Acknowledge */
hi2c->Instance->CR1 |= I2C_CR1_ACK;
/* Send Slave Address */
int ret = send_addr_byte(hi2c, I2C_7BIT_ADD_READ(addr << 1), Timeout, tickstart);
if (ret != 0) {
return ret;
}
if (len == 0U) {
/* Clear ADDR flag */
__HAL_I2C_CLEAR_ADDRFLAG(hi2c);
/* Generate Stop */
if (stop) {
hi2c->Instance->CR1 |= I2C_CR1_STOP;
}
} else if (len == 1U) {
/* Disable Acknowledge */
hi2c->Instance->CR1 &= ~I2C_CR1_ACK;
/* Clear ADDR flag */
__HAL_I2C_CLEAR_ADDRFLAG(hi2c);
/* Generate Stop */
if (stop) {
hi2c->Instance->CR1 |= I2C_CR1_STOP;
}
} else if (len == 2U) {
/* Disable Acknowledge */
hi2c->Instance->CR1 &= ~I2C_CR1_ACK;
/* Enable Pos */
hi2c->Instance->CR1 |= I2C_CR1_POS;
/* Clear ADDR flag */
__HAL_I2C_CLEAR_ADDRFLAG(hi2c);
} else {
/* Enable Acknowledge */
hi2c->Instance->CR1 |= I2C_CR1_ACK;
/* Clear ADDR flag */
__HAL_I2C_CLEAR_ADDRFLAG(hi2c);
}
while (len > 0U) {
if (len <= 3U) {
if (len == 1U) {
/* Wait until RXNE flag is set */
int ret = I2C_WaitOnRXNEFlagUntilTimeout(hi2c, Timeout, tickstart);
if (ret != 0) {
return ret;
}
/* Read data from DR */
*dest++ = hi2c->Instance->DR;
len--;
} else if (len == 2U) {
/* Wait until BTF flag is set */
if (!I2C_WaitOnFlagUntilTimeout(hi2c, I2C_FLAG_BTF, RESET, Timeout, tickstart)) {
return -MP_ETIMEDOUT;
}
/* Generate Stop */
if (stop) {
hi2c->Instance->CR1 |= I2C_CR1_STOP;
}
/* Read data from DR */
*dest++ = hi2c->Instance->DR;
len--;
/* Read data from DR */
*dest++ = hi2c->Instance->DR;
len--;
} else {
/* Wait until BTF flag is set */
if (!I2C_WaitOnFlagUntilTimeout(hi2c, I2C_FLAG_BTF, RESET, Timeout, tickstart)) {
return -MP_ETIMEDOUT;
}
/* Disable Acknowledge */
hi2c->Instance->CR1 &= ~I2C_CR1_ACK;
/* Read data from DR */
*dest++ = hi2c->Instance->DR;
len--;
/* Wait until BTF flag is set */
if (!I2C_WaitOnFlagUntilTimeout(hi2c, I2C_FLAG_BTF, RESET, Timeout, tickstart)) {
return -MP_ETIMEDOUT;
}
/* Generate Stop */
if (stop) {
hi2c->Instance->CR1 |= I2C_CR1_STOP;
}
/* Read data from DR */
*dest++ = hi2c->Instance->DR;
len--;
/* Read data from DR */
*dest++ = hi2c->Instance->DR;
len--;
}
} else {
/* Wait until RXNE flag is set */
int ret = I2C_WaitOnRXNEFlagUntilTimeout(hi2c, Timeout, tickstart);
if (ret != 0) {
return ret;
}
/* Read data from DR */
*dest++ = hi2c->Instance->DR;
len--;
if (__HAL_I2C_GET_FLAG(hi2c, I2C_FLAG_BTF) == SET) {
/* Read data from DR */
*dest++ = hi2c->Instance->DR;
len--;
}
}
}
return 0;
}
// this function is based on STM code
int machine_hard_i2c_writeto(mp_obj_base_t *self_in, uint16_t addr, const uint8_t *src, size_t len, bool stop) {
machine_hard_i2c_obj_t *self = (machine_hard_i2c_obj_t*)self_in;
I2C_HandleTypeDef *hi2c = self->pyb->i2c;
uint32_t Timeout = *self->timeout;
/* Init tickstart for timeout management*/
uint32_t tickstart = HAL_GetTick();
#if 0
// TODO: for multi-master, here we could wait for the bus to be free
// we'd need a flag to tell if we were in the middle of a set of transactions
// (ie didn't send a stop bit in the last call)
/* Wait until BUSY flag is reset */
if (!I2C_WaitOnFlagUntilTimeout(hi2c, I2C_FLAG_BUSY, SET, I2C_TIMEOUT_BUSY_FLAG, tickstart)) {
return -MP_EBUSY;
}
#endif
/* Check if the I2C is already enabled */
if ((hi2c->Instance->CR1 & I2C_CR1_PE) != I2C_CR1_PE) {
/* Enable I2C peripheral */
__HAL_I2C_ENABLE(hi2c);
}
/* Disable Pos */
hi2c->Instance->CR1 &= ~I2C_CR1_POS;
/* Send Slave Address */
int ret = send_addr_byte(hi2c, I2C_7BIT_ADD_WRITE(addr << 1), Timeout, tickstart);
if (ret != 0) {
return ret;
}
/* Clear ADDR flag */
__HAL_I2C_CLEAR_ADDRFLAG(hi2c);
int num_acks = 0;
while (len > 0U) {
/* Wait until TXE flag is set */
while (__HAL_I2C_GET_FLAG(hi2c, I2C_FLAG_TXE) == RESET) {
/* Check if a NACK is detected */
if (I2C_IsAcknowledgeFailed(hi2c)) {
goto nack;
}
/* Check for the Timeout */
if (Timeout != HAL_MAX_DELAY) {
if ((Timeout == 0U) || ((HAL_GetTick()-tickstart) > Timeout)) {
goto timeout;
}
}
}
/* Write data to DR */
hi2c->Instance->DR = *src++;
len--;
/* Wait until BTF flag is set */
while (__HAL_I2C_GET_FLAG(hi2c, I2C_FLAG_BTF) == RESET) {
/* Check if a NACK is detected */
if (I2C_IsAcknowledgeFailed(hi2c)) {
goto nack;
}
/* Check for the Timeout */
if (Timeout != HAL_MAX_DELAY) {
if ((Timeout == 0U) || ((HAL_GetTick()-tickstart) > Timeout)) {
goto timeout;
}
}
}
++num_acks;
}
nack:
/* Generate Stop */
if (stop) {
hi2c->Instance->CR1 |= I2C_CR1_STOP;
}
return num_acks;
timeout:
// timeout, release the bus cleanly
hi2c->Instance->CR1 |= I2C_CR1_STOP;
return -MP_ETIMEDOUT;
}
#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[] = {
#if defined(MICROPY_HW_I2C1_SCL)
{{&machine_hard_i2c_type}, 1, 500, &MICROPY_HW_I2C1_SCL, &MICROPY_HW_I2C1_SDA},
#else
{{NULL}, 0, 0, NULL, NULL},
#endif
#if defined(MICROPY_HW_I2C2_SCL)
{{&machine_hard_i2c_type}, 1, 500, &MICROPY_HW_I2C2_SCL, &MICROPY_HW_I2C2_SDA},
#else
{{NULL}, 0, 0, NULL, NULL},
#endif
#if defined(MICROPY_HW_I2C3_SCL)
{{&machine_hard_i2c_type}, 1, 500, &MICROPY_HW_I2C3_SCL, &MICROPY_HW_I2C3_SDA},
#else
{{NULL}, 0, 0, NULL, NULL},
#endif
#if defined(MICROPY_HW_I2C4_SCL)
{{&machine_hard_i2c_type}, 1, 500, &MICROPY_HW_I2C4_SCL, &MICROPY_HW_I2C4_SDA},
#else
{{NULL}, 0, 0, NULL, NULL},
#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_readfrom mp_machine_soft_i2c_readfrom
#define machine_hard_i2c_writeto mp_machine_soft_i2c_writeto
#endif
/******************************************************************************/
/* MicroPython bindings for machine API */
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) {
// parse args
enum { ARG_id, ARG_scl, ARG_sda, ARG_freq, ARG_timeout };
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 = 1000} },
};
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);
// work out i2c bus
int i2c_id = 0;
if (MP_OBJ_IS_STR(args[ARG_id].u_obj)) {
const char *port = mp_obj_str_get_str(args[ARG_id].u_obj);
if (0) {
#ifdef MICROPY_HW_I2C1_NAME
} else if (strcmp(port, MICROPY_HW_I2C1_NAME) == 0) {
i2c_id = 1;
#endif
#ifdef MICROPY_HW_I2C2_NAME
} else if (strcmp(port, MICROPY_HW_I2C2_NAME) == 0) {
i2c_id = 2;
#endif
#ifdef MICROPY_HW_I2C3_NAME
} else if (strcmp(port, MICROPY_HW_I2C3_NAME) == 0) {
i2c_id = 3;
#endif
} else {
nlr_raise(mp_obj_new_exception_msg_varg(&mp_type_ValueError,
"I2C(%s) does not exist", port));
}
} else {
i2c_id = mp_obj_get_int(args[ARG_id].u_obj);
if (i2c_id < 1 || i2c_id > MP_ARRAY_SIZE(machine_hard_i2c_obj)
|| machine_hard_i2c_obj[i2c_id - 1].base.type == NULL) {
nlr_raise(mp_obj_new_exception_msg_varg(&mp_type_ValueError,
"I2C(%d) does not exist", i2c_id));
}
}
// get static peripheral object
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("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);
return MP_OBJ_FROM_PTR(self);
}
STATIC const mp_machine_i2c_p_t machine_hard_i2c_p = {
.readfrom = machine_hard_i2c_readfrom,
.writeto = machine_hard_i2c_writeto,
};
STATIC const mp_obj_type_t machine_hard_i2c_type = {
{ &mp_type_type },
.name = MP_QSTR_I2C,
.print = machine_hard_i2c_print,
.make_new = machine_hard_i2c_make_new,
.protocol = &machine_hard_i2c_p,
.locals_dict = (mp_obj_dict_t*)&mp_machine_soft_i2c_locals_dict,
};
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