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circuitpython/ports/stm32/machine_i2c.c
Damien George 2dca693c24 stm32: Change pin_X and pyb_pin_X identifiers to be pointers to objects. 
Rather than pin objects themselves.  The actual object is now pin_X_obj and
defines are provided so that pin_X is &pin_X_obj.  This makes it so that
code that uses pin objects doesn't need to know if they are literals or
objects (that need pointers taken) or something else.  They are just
entities that can be passed to the map_hal_pin_xxx functions.  This mirrors
how the core handles constant objects (eg mp_const_none which is
&mp_const_none_obj) and allows for the possibility of different
implementations of the pin layer.

For example, prior to this patch there was the following:

    extern const pin_obj_t pin_A0;
    #define pyb_pin_X1 pin_A0
    ...
    mp_hal_pin_high(&pin_A0);

and now there is:

    extern const pin_obj_t pin_A0_obj;
    #define pin_A0 (&pin_A0_obj)
    #define pyb_pin_X1 pin_A0
    ...
    mp_hal_pin_high(pin_A0);

This patch should have minimal effect on board configuration files.  The
only change that may be needed is if a board has .c files that configure
pins.
2018-03-28 16:29:50 +11:00

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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 "i2c.h"
#if MICROPY_HW_ENABLE_HW_I2C
STATIC const mp_obj_type_t machine_hard_i2c_type;
#if defined(STM32F4)
// 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),
*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) doesn't 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) doesn't 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,
};
#endif // MICROPY_HW_ENABLE_HW_I2C
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