655 lines
14 KiB
C
655 lines
14 KiB
C
/*
|
|
* Copyright (c) 2016 BayLibre, SAS
|
|
* Copyright (c) 2017 Linaro Ltd
|
|
*
|
|
* SPDX-License-Identifier: Apache-2.0
|
|
*
|
|
* I2C Driver for: STM32F0, STM32F3, STM32F7, STM32L0, STM32L4 and STM32WB
|
|
*
|
|
*/
|
|
|
|
#include <clock_control/stm32_clock_control.h>
|
|
#include <drivers/clock_control.h>
|
|
#include <sys/util.h>
|
|
#include <kernel.h>
|
|
#include <soc.h>
|
|
#include <errno.h>
|
|
#include <drivers/i2c.h>
|
|
#include "i2c_ll_stm32.h"
|
|
|
|
#define LOG_LEVEL CONFIG_I2C_LOG_LEVEL
|
|
#include <logging/log.h>
|
|
LOG_MODULE_REGISTER(i2c_ll_stm32_v2);
|
|
|
|
#include "i2c-priv.h"
|
|
|
|
static inline void msg_init(struct device *dev, struct i2c_msg *msg,
|
|
u8_t *next_msg_flags, u16_t slave,
|
|
uint32_t transfer)
|
|
{
|
|
const struct i2c_stm32_config *cfg = DEV_CFG(dev);
|
|
struct i2c_stm32_data *data = DEV_DATA(dev);
|
|
I2C_TypeDef *i2c = cfg->i2c;
|
|
|
|
if (LL_I2C_IsEnabledReloadMode(i2c)) {
|
|
LL_I2C_SetTransferSize(i2c, msg->len);
|
|
} else {
|
|
if (I2C_ADDR_10_BITS & data->dev_config) {
|
|
LL_I2C_SetMasterAddressingMode(i2c,
|
|
LL_I2C_ADDRESSING_MODE_10BIT);
|
|
LL_I2C_SetSlaveAddr(i2c, (uint32_t) slave);
|
|
} else {
|
|
LL_I2C_SetMasterAddressingMode(i2c,
|
|
LL_I2C_ADDRESSING_MODE_7BIT);
|
|
LL_I2C_SetSlaveAddr(i2c, (uint32_t) slave << 1);
|
|
}
|
|
|
|
if (!(msg->flags & I2C_MSG_STOP) && next_msg_flags &&
|
|
!(*next_msg_flags & I2C_MSG_RESTART)) {
|
|
LL_I2C_EnableReloadMode(i2c);
|
|
} else {
|
|
LL_I2C_DisableReloadMode(i2c);
|
|
}
|
|
LL_I2C_DisableAutoEndMode(i2c);
|
|
LL_I2C_SetTransferRequest(i2c, transfer);
|
|
LL_I2C_SetTransferSize(i2c, msg->len);
|
|
|
|
#if defined(CONFIG_I2C_SLAVE)
|
|
data->master_active = true;
|
|
#endif
|
|
LL_I2C_Enable(i2c);
|
|
|
|
LL_I2C_GenerateStartCondition(i2c);
|
|
}
|
|
}
|
|
|
|
#ifdef CONFIG_I2C_STM32_INTERRUPT
|
|
|
|
static void stm32_i2c_disable_transfer_interrupts(struct device *dev)
|
|
{
|
|
const struct i2c_stm32_config *cfg = DEV_CFG(dev);
|
|
I2C_TypeDef *i2c = cfg->i2c;
|
|
|
|
LL_I2C_DisableIT_TX(i2c);
|
|
LL_I2C_DisableIT_RX(i2c);
|
|
LL_I2C_DisableIT_STOP(i2c);
|
|
LL_I2C_DisableIT_NACK(i2c);
|
|
LL_I2C_DisableIT_TC(i2c);
|
|
LL_I2C_DisableIT_ERR(i2c);
|
|
}
|
|
|
|
static void stm32_i2c_enable_transfer_interrupts(struct device *dev)
|
|
{
|
|
const struct i2c_stm32_config *cfg = DEV_CFG(dev);
|
|
I2C_TypeDef *i2c = cfg->i2c;
|
|
|
|
LL_I2C_EnableIT_STOP(i2c);
|
|
LL_I2C_EnableIT_NACK(i2c);
|
|
LL_I2C_EnableIT_TC(i2c);
|
|
LL_I2C_EnableIT_ERR(i2c);
|
|
}
|
|
|
|
static void stm32_i2c_master_mode_end(struct device *dev)
|
|
{
|
|
const struct i2c_stm32_config *cfg = DEV_CFG(dev);
|
|
struct i2c_stm32_data *data = DEV_DATA(dev);
|
|
I2C_TypeDef *i2c = cfg->i2c;
|
|
|
|
stm32_i2c_disable_transfer_interrupts(dev);
|
|
|
|
#if defined(CONFIG_I2C_SLAVE)
|
|
data->master_active = false;
|
|
if (!data->slave_attached) {
|
|
LL_I2C_Disable(i2c);
|
|
}
|
|
#else
|
|
LL_I2C_Disable(i2c);
|
|
#endif
|
|
k_sem_give(&data->device_sync_sem);
|
|
}
|
|
|
|
#if defined(CONFIG_I2C_SLAVE)
|
|
static void stm32_i2c_slave_event(struct device *dev)
|
|
{
|
|
const struct i2c_stm32_config *cfg = DEV_CFG(dev);
|
|
struct i2c_stm32_data *data = DEV_DATA(dev);
|
|
I2C_TypeDef *i2c = cfg->i2c;
|
|
const struct i2c_slave_callbacks *slave_cb =
|
|
data->slave_cfg->callbacks;
|
|
|
|
if (LL_I2C_IsActiveFlag_TXIS(i2c)) {
|
|
u8_t val;
|
|
|
|
slave_cb->read_processed(data->slave_cfg, &val);
|
|
LL_I2C_TransmitData8(i2c, val);
|
|
return;
|
|
}
|
|
|
|
if (LL_I2C_IsActiveFlag_RXNE(i2c)) {
|
|
u8_t val = LL_I2C_ReceiveData8(i2c);
|
|
|
|
if (slave_cb->write_received(data->slave_cfg, val)) {
|
|
LL_I2C_AcknowledgeNextData(i2c, LL_I2C_NACK);
|
|
}
|
|
return;
|
|
}
|
|
|
|
if (LL_I2C_IsActiveFlag_NACK(i2c)) {
|
|
LL_I2C_ClearFlag_NACK(i2c);
|
|
}
|
|
|
|
if (LL_I2C_IsActiveFlag_STOP(i2c)) {
|
|
stm32_i2c_disable_transfer_interrupts(dev);
|
|
|
|
/* Flush remaining TX byte before clearing Stop Flag */
|
|
LL_I2C_ClearFlag_TXE(i2c);
|
|
|
|
LL_I2C_ClearFlag_STOP(i2c);
|
|
|
|
slave_cb->stop(data->slave_cfg);
|
|
|
|
/* Prepare to ACK next transmissions address byte */
|
|
LL_I2C_AcknowledgeNextData(i2c, LL_I2C_ACK);
|
|
}
|
|
|
|
if (LL_I2C_IsActiveFlag_ADDR(i2c)) {
|
|
u32_t dir;
|
|
|
|
LL_I2C_ClearFlag_ADDR(i2c);
|
|
|
|
dir = LL_I2C_GetTransferDirection(i2c);
|
|
if (dir == LL_I2C_DIRECTION_WRITE) {
|
|
slave_cb->write_requested(data->slave_cfg);
|
|
LL_I2C_EnableIT_RX(i2c);
|
|
} else {
|
|
u8_t val;
|
|
|
|
slave_cb->read_requested(data->slave_cfg, &val);
|
|
LL_I2C_TransmitData8(i2c, val);
|
|
LL_I2C_EnableIT_TX(i2c);
|
|
}
|
|
|
|
stm32_i2c_enable_transfer_interrupts(dev);
|
|
}
|
|
}
|
|
|
|
/* Attach and start I2C as slave */
|
|
int i2c_stm32_slave_register(struct device *dev,
|
|
struct i2c_slave_config *config)
|
|
{
|
|
const struct i2c_stm32_config *cfg = DEV_CFG(dev);
|
|
struct i2c_stm32_data *data = DEV_DATA(dev);
|
|
I2C_TypeDef *i2c = cfg->i2c;
|
|
u32_t bitrate_cfg;
|
|
int ret;
|
|
|
|
if (!config) {
|
|
return -EINVAL;
|
|
}
|
|
|
|
if (data->slave_attached) {
|
|
return -EBUSY;
|
|
}
|
|
|
|
if (data->master_active) {
|
|
return -EBUSY;
|
|
}
|
|
|
|
bitrate_cfg = i2c_map_dt_bitrate(cfg->bitrate);
|
|
|
|
ret = i2c_stm32_runtime_configure(dev, bitrate_cfg);
|
|
if (ret < 0) {
|
|
LOG_ERR("i2c: failure initializing");
|
|
return ret;
|
|
}
|
|
|
|
data->slave_cfg = config;
|
|
|
|
LL_I2C_Enable(i2c);
|
|
|
|
LL_I2C_SetOwnAddress1(i2c, config->address << 1,
|
|
LL_I2C_OWNADDRESS1_7BIT);
|
|
LL_I2C_EnableOwnAddress1(i2c);
|
|
|
|
data->slave_attached = true;
|
|
|
|
LOG_DBG("i2c: slave registered");
|
|
|
|
LL_I2C_EnableIT_ADDR(i2c);
|
|
|
|
return 0;
|
|
}
|
|
|
|
int i2c_stm32_slave_unregister(struct device *dev,
|
|
struct i2c_slave_config *config)
|
|
{
|
|
const struct i2c_stm32_config *cfg = DEV_CFG(dev);
|
|
struct i2c_stm32_data *data = DEV_DATA(dev);
|
|
I2C_TypeDef *i2c = cfg->i2c;
|
|
|
|
if (!data->slave_attached) {
|
|
return -EINVAL;
|
|
}
|
|
|
|
if (data->master_active) {
|
|
return -EBUSY;
|
|
}
|
|
|
|
LL_I2C_DisableOwnAddress1(i2c);
|
|
|
|
LL_I2C_DisableIT_ADDR(i2c);
|
|
stm32_i2c_disable_transfer_interrupts(dev);
|
|
|
|
LL_I2C_ClearFlag_NACK(i2c);
|
|
LL_I2C_ClearFlag_STOP(i2c);
|
|
LL_I2C_ClearFlag_ADDR(i2c);
|
|
|
|
LL_I2C_Disable(i2c);
|
|
|
|
data->slave_attached = false;
|
|
|
|
LOG_DBG("i2c: slave unregistered");
|
|
|
|
return 0;
|
|
}
|
|
|
|
#endif /* defined(CONFIG_I2C_SLAVE) */
|
|
|
|
static void stm32_i2c_event(struct device *dev)
|
|
{
|
|
const struct i2c_stm32_config *cfg = DEV_CFG(dev);
|
|
struct i2c_stm32_data *data = DEV_DATA(dev);
|
|
I2C_TypeDef *i2c = cfg->i2c;
|
|
|
|
#if defined(CONFIG_I2C_SLAVE)
|
|
if (data->slave_attached && !data->master_active) {
|
|
stm32_i2c_slave_event(dev);
|
|
return;
|
|
}
|
|
#endif
|
|
if (data->current.len) {
|
|
/* Send next byte */
|
|
if (LL_I2C_IsActiveFlag_TXIS(i2c)) {
|
|
LL_I2C_TransmitData8(i2c, *data->current.buf);
|
|
}
|
|
|
|
/* Receive next byte */
|
|
if (LL_I2C_IsActiveFlag_RXNE(i2c)) {
|
|
*data->current.buf = LL_I2C_ReceiveData8(i2c);
|
|
}
|
|
|
|
data->current.buf++;
|
|
data->current.len--;
|
|
}
|
|
|
|
/* NACK received */
|
|
if (LL_I2C_IsActiveFlag_NACK(i2c)) {
|
|
LL_I2C_ClearFlag_NACK(i2c);
|
|
data->current.is_nack = 1U;
|
|
/*
|
|
* AutoEndMode is always disabled in master mode,
|
|
* so send a stop condition manually
|
|
*/
|
|
LL_I2C_GenerateStopCondition(i2c);
|
|
return;
|
|
}
|
|
|
|
/* STOP received */
|
|
if (LL_I2C_IsActiveFlag_STOP(i2c)) {
|
|
LL_I2C_ClearFlag_STOP(i2c);
|
|
LL_I2C_DisableReloadMode(i2c);
|
|
goto end;
|
|
}
|
|
|
|
/* Transfer Complete or Transfer Complete Reload */
|
|
if (LL_I2C_IsActiveFlag_TC(i2c) ||
|
|
LL_I2C_IsActiveFlag_TCR(i2c)) {
|
|
/* Issue stop condition if necessary */
|
|
if (data->current.msg->flags & I2C_MSG_STOP) {
|
|
LL_I2C_GenerateStopCondition(i2c);
|
|
} else {
|
|
stm32_i2c_disable_transfer_interrupts(dev);
|
|
k_sem_give(&data->device_sync_sem);
|
|
}
|
|
}
|
|
|
|
return;
|
|
end:
|
|
stm32_i2c_master_mode_end(dev);
|
|
}
|
|
|
|
static int stm32_i2c_error(struct device *dev)
|
|
{
|
|
const struct i2c_stm32_config *cfg = DEV_CFG(dev);
|
|
struct i2c_stm32_data *data = DEV_DATA(dev);
|
|
I2C_TypeDef *i2c = cfg->i2c;
|
|
|
|
#if defined(CONFIG_I2C_SLAVE)
|
|
if (data->slave_attached && !data->master_active) {
|
|
/* No need for a slave error function right now. */
|
|
return 0;
|
|
}
|
|
#endif
|
|
|
|
if (LL_I2C_IsActiveFlag_ARLO(i2c)) {
|
|
LL_I2C_ClearFlag_ARLO(i2c);
|
|
data->current.is_arlo = 1U;
|
|
goto end;
|
|
}
|
|
|
|
if (LL_I2C_IsActiveFlag_BERR(i2c)) {
|
|
LL_I2C_ClearFlag_BERR(i2c);
|
|
data->current.is_err = 1U;
|
|
goto end;
|
|
}
|
|
|
|
return 0;
|
|
end:
|
|
stm32_i2c_master_mode_end(dev);
|
|
return -EIO;
|
|
}
|
|
|
|
#ifdef CONFIG_I2C_STM32_COMBINED_INTERRUPT
|
|
void stm32_i2c_combined_isr(void *arg)
|
|
{
|
|
struct device *dev = (struct device *) arg;
|
|
|
|
if (stm32_i2c_error(dev)) {
|
|
return;
|
|
}
|
|
stm32_i2c_event(dev);
|
|
}
|
|
#else
|
|
|
|
void stm32_i2c_event_isr(void *arg)
|
|
{
|
|
struct device *dev = (struct device *) arg;
|
|
|
|
stm32_i2c_event(dev);
|
|
}
|
|
|
|
void stm32_i2c_error_isr(void *arg)
|
|
{
|
|
struct device *dev = (struct device *) arg;
|
|
|
|
stm32_i2c_error(dev);
|
|
}
|
|
#endif
|
|
|
|
int stm32_i2c_msg_write(struct device *dev, struct i2c_msg *msg,
|
|
u8_t *next_msg_flags, uint16_t slave)
|
|
{
|
|
const struct i2c_stm32_config *cfg = DEV_CFG(dev);
|
|
struct i2c_stm32_data *data = DEV_DATA(dev);
|
|
I2C_TypeDef *i2c = cfg->i2c;
|
|
|
|
data->current.len = msg->len;
|
|
data->current.buf = msg->buf;
|
|
data->current.is_write = 1U;
|
|
data->current.is_nack = 0U;
|
|
data->current.is_err = 0U;
|
|
data->current.msg = msg;
|
|
|
|
msg_init(dev, msg, next_msg_flags, slave, LL_I2C_REQUEST_WRITE);
|
|
|
|
stm32_i2c_enable_transfer_interrupts(dev);
|
|
LL_I2C_EnableIT_TX(i2c);
|
|
|
|
k_sem_take(&data->device_sync_sem, K_FOREVER);
|
|
|
|
if (data->current.is_nack || data->current.is_err ||
|
|
data->current.is_arlo) {
|
|
goto error;
|
|
}
|
|
|
|
return 0;
|
|
error:
|
|
if (data->current.is_arlo) {
|
|
LOG_DBG("%s: ARLO %d", __func__,
|
|
data->current.is_arlo);
|
|
data->current.is_arlo = 0U;
|
|
}
|
|
|
|
if (data->current.is_nack) {
|
|
LOG_DBG("%s: NACK", __func__);
|
|
data->current.is_nack = 0U;
|
|
}
|
|
|
|
if (data->current.is_err) {
|
|
LOG_DBG("%s: ERR %d", __func__,
|
|
data->current.is_err);
|
|
data->current.is_err = 0U;
|
|
}
|
|
|
|
return -EIO;
|
|
}
|
|
|
|
int stm32_i2c_msg_read(struct device *dev, struct i2c_msg *msg,
|
|
u8_t *next_msg_flags, uint16_t slave)
|
|
{
|
|
const struct i2c_stm32_config *cfg = DEV_CFG(dev);
|
|
struct i2c_stm32_data *data = DEV_DATA(dev);
|
|
I2C_TypeDef *i2c = cfg->i2c;
|
|
|
|
data->current.len = msg->len;
|
|
data->current.buf = msg->buf;
|
|
data->current.is_write = 0U;
|
|
data->current.is_arlo = 0U;
|
|
data->current.is_err = 0U;
|
|
data->current.is_nack = 0U;
|
|
data->current.msg = msg;
|
|
|
|
msg_init(dev, msg, next_msg_flags, slave, LL_I2C_REQUEST_READ);
|
|
|
|
stm32_i2c_enable_transfer_interrupts(dev);
|
|
LL_I2C_EnableIT_RX(i2c);
|
|
|
|
k_sem_take(&data->device_sync_sem, K_FOREVER);
|
|
|
|
if (data->current.is_nack || data->current.is_err ||
|
|
data->current.is_arlo) {
|
|
goto error;
|
|
}
|
|
|
|
return 0;
|
|
error:
|
|
if (data->current.is_arlo) {
|
|
LOG_DBG("%s: ARLO %d", __func__,
|
|
data->current.is_arlo);
|
|
data->current.is_arlo = 0U;
|
|
}
|
|
|
|
if (data->current.is_nack) {
|
|
LOG_DBG("%s: NACK", __func__);
|
|
data->current.is_nack = 0U;
|
|
}
|
|
|
|
if (data->current.is_err) {
|
|
LOG_DBG("%s: ERR %d", __func__,
|
|
data->current.is_err);
|
|
data->current.is_err = 0U;
|
|
}
|
|
|
|
return -EIO;
|
|
}
|
|
|
|
#else /* !CONFIG_I2C_STM32_INTERRUPT */
|
|
static inline int check_errors(struct device *dev, const char *funcname)
|
|
{
|
|
const struct i2c_stm32_config *cfg = DEV_CFG(dev);
|
|
I2C_TypeDef *i2c = cfg->i2c;
|
|
|
|
if (LL_I2C_IsActiveFlag_NACK(i2c)) {
|
|
LL_I2C_ClearFlag_NACK(i2c);
|
|
LOG_DBG("%s: NACK", funcname);
|
|
goto error;
|
|
}
|
|
|
|
if (LL_I2C_IsActiveFlag_ARLO(i2c)) {
|
|
LL_I2C_ClearFlag_ARLO(i2c);
|
|
LOG_DBG("%s: ARLO", funcname);
|
|
goto error;
|
|
}
|
|
|
|
if (LL_I2C_IsActiveFlag_OVR(i2c)) {
|
|
LL_I2C_ClearFlag_OVR(i2c);
|
|
LOG_DBG("%s: OVR", funcname);
|
|
goto error;
|
|
}
|
|
|
|
if (LL_I2C_IsActiveFlag_BERR(i2c)) {
|
|
LL_I2C_ClearFlag_BERR(i2c);
|
|
LOG_DBG("%s: BERR", funcname);
|
|
goto error;
|
|
}
|
|
|
|
return 0;
|
|
error:
|
|
if (LL_I2C_IsEnabledReloadMode(i2c)) {
|
|
LL_I2C_DisableReloadMode(i2c);
|
|
}
|
|
return -EIO;
|
|
}
|
|
|
|
static inline int msg_done(struct device *dev, unsigned int current_msg_flags)
|
|
{
|
|
const struct i2c_stm32_config *cfg = DEV_CFG(dev);
|
|
I2C_TypeDef *i2c = cfg->i2c;
|
|
|
|
/* Wait for transfer to complete */
|
|
while (!LL_I2C_IsActiveFlag_TC(i2c) && !LL_I2C_IsActiveFlag_TCR(i2c)) {
|
|
if (check_errors(dev, __func__)) {
|
|
return -EIO;
|
|
}
|
|
}
|
|
/* Issue stop condition if necessary */
|
|
if (current_msg_flags & I2C_MSG_STOP) {
|
|
LL_I2C_GenerateStopCondition(i2c);
|
|
while (!LL_I2C_IsActiveFlag_STOP(i2c)) {
|
|
}
|
|
|
|
LL_I2C_ClearFlag_STOP(i2c);
|
|
LL_I2C_DisableReloadMode(i2c);
|
|
}
|
|
|
|
return 0;
|
|
}
|
|
|
|
int stm32_i2c_msg_write(struct device *dev, struct i2c_msg *msg,
|
|
u8_t *next_msg_flags, uint16_t slave)
|
|
{
|
|
const struct i2c_stm32_config *cfg = DEV_CFG(dev);
|
|
I2C_TypeDef *i2c = cfg->i2c;
|
|
unsigned int len = 0U;
|
|
u8_t *buf = msg->buf;
|
|
|
|
msg_init(dev, msg, next_msg_flags, slave, LL_I2C_REQUEST_WRITE);
|
|
|
|
len = msg->len;
|
|
while (len) {
|
|
while (1) {
|
|
if (LL_I2C_IsActiveFlag_TXIS(i2c)) {
|
|
break;
|
|
}
|
|
|
|
if (check_errors(dev, __func__)) {
|
|
return -EIO;
|
|
}
|
|
}
|
|
|
|
LL_I2C_TransmitData8(i2c, *buf);
|
|
buf++;
|
|
len--;
|
|
}
|
|
|
|
return msg_done(dev, msg->flags);
|
|
}
|
|
|
|
int stm32_i2c_msg_read(struct device *dev, struct i2c_msg *msg,
|
|
u8_t *next_msg_flags, uint16_t slave)
|
|
{
|
|
const struct i2c_stm32_config *cfg = DEV_CFG(dev);
|
|
I2C_TypeDef *i2c = cfg->i2c;
|
|
unsigned int len = 0U;
|
|
u8_t *buf = msg->buf;
|
|
|
|
msg_init(dev, msg, next_msg_flags, slave, LL_I2C_REQUEST_READ);
|
|
|
|
len = msg->len;
|
|
while (len) {
|
|
while (!LL_I2C_IsActiveFlag_RXNE(i2c)) {
|
|
if (check_errors(dev, __func__)) {
|
|
return -EIO;
|
|
}
|
|
}
|
|
|
|
*buf = LL_I2C_ReceiveData8(i2c);
|
|
buf++;
|
|
len--;
|
|
}
|
|
|
|
return msg_done(dev, msg->flags);
|
|
}
|
|
#endif
|
|
|
|
int stm32_i2c_configure_timing(struct device *dev, u32_t clock)
|
|
{
|
|
const struct i2c_stm32_config *cfg = DEV_CFG(dev);
|
|
struct i2c_stm32_data *data = DEV_DATA(dev);
|
|
I2C_TypeDef *i2c = cfg->i2c;
|
|
u32_t i2c_hold_time_min, i2c_setup_time_min;
|
|
u32_t i2c_h_min_time, i2c_l_min_time;
|
|
u32_t presc = 1U;
|
|
u32_t timing = 0U;
|
|
|
|
switch (I2C_SPEED_GET(data->dev_config)) {
|
|
case I2C_SPEED_STANDARD:
|
|
i2c_h_min_time = 4000U;
|
|
i2c_l_min_time = 4700U;
|
|
i2c_hold_time_min = 500U;
|
|
i2c_setup_time_min = 1250U;
|
|
break;
|
|
case I2C_SPEED_FAST:
|
|
i2c_h_min_time = 600U;
|
|
i2c_l_min_time = 1300U;
|
|
i2c_hold_time_min = 375U;
|
|
i2c_setup_time_min = 500U;
|
|
break;
|
|
default:
|
|
return -EINVAL;
|
|
}
|
|
|
|
/* Calculate period until prescaler matches */
|
|
do {
|
|
u32_t t_presc = clock / presc;
|
|
u32_t ns_presc = NSEC_PER_SEC / t_presc;
|
|
u32_t sclh = i2c_h_min_time / ns_presc;
|
|
u32_t scll = i2c_l_min_time / ns_presc;
|
|
u32_t sdadel = i2c_hold_time_min / ns_presc;
|
|
u32_t scldel = i2c_setup_time_min / ns_presc;
|
|
|
|
if ((sclh - 1) > 255 || (scll - 1) > 255) {
|
|
++presc;
|
|
continue;
|
|
}
|
|
|
|
if (sdadel > 15 || (scldel - 1) > 15) {
|
|
++presc;
|
|
continue;
|
|
}
|
|
|
|
timing = __LL_I2C_CONVERT_TIMINGS(presc - 1,
|
|
scldel - 1, sdadel, sclh - 1, scll - 1);
|
|
break;
|
|
} while (presc < 16);
|
|
|
|
if (presc >= 16U) {
|
|
LOG_DBG("I2C:failed to find prescaler value");
|
|
return -EINVAL;
|
|
}
|
|
|
|
LL_I2C_SetTiming(i2c, timing);
|
|
|
|
return 0;
|
|
}
|