blob: a685ebebeb786775da1cd073e539613f5124d2cc [file] [log] [blame]
/*
* Copyright (c) 2016 BayLibre, SAS
* Copyright (c) 2017 Linaro Ltd
*
* SPDX-License-Identifier: Apache-2.0
*
* I2C Driver for: STM32F0, STM32F3, STM32F7, STM32L0, STM32L4, STM32WB and
* STM32WL
*
*/
#include <zephyr/drivers/clock_control/stm32_clock_control.h>
#include <zephyr/drivers/clock_control.h>
#include <zephyr/sys/util.h>
#include <zephyr/kernel.h>
#include <soc.h>
#include <stm32_ll_i2c.h>
#include <errno.h>
#include <zephyr/drivers/i2c.h>
#include <zephyr/pm/device.h>
#include <zephyr/pm/device_runtime.h>
#include "i2c_ll_stm32.h"
#define LOG_LEVEL CONFIG_I2C_LOG_LEVEL
#include <zephyr/logging/log.h>
LOG_MODULE_REGISTER(i2c_ll_stm32_v2);
#include "i2c-priv.h"
#define STM32_I2C_TRANSFER_TIMEOUT_MSEC 500
static inline void msg_init(const struct device *dev, struct i2c_msg *msg,
uint8_t *next_msg_flags, uint16_t slave,
uint32_t transfer)
{
const struct i2c_stm32_config *cfg = dev->config;
struct i2c_stm32_data *data = dev->data;
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_TARGET)
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(const struct device *dev)
{
const struct i2c_stm32_config *cfg = dev->config;
struct i2c_stm32_data *data = dev->data;
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);
if (!data->smbalert_active) {
LL_I2C_DisableIT_ERR(i2c);
}
}
static void stm32_i2c_enable_transfer_interrupts(const struct device *dev)
{
const struct i2c_stm32_config *cfg = dev->config;
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(const struct device *dev)
{
const struct i2c_stm32_config *cfg = dev->config;
struct i2c_stm32_data *data = dev->data;
I2C_TypeDef *i2c = cfg->i2c;
stm32_i2c_disable_transfer_interrupts(dev);
if (LL_I2C_IsEnabledReloadMode(i2c)) {
LL_I2C_DisableReloadMode(i2c);
}
#if defined(CONFIG_I2C_TARGET)
data->master_active = false;
if (!data->slave_attached && !data->smbalert_active) {
LL_I2C_Disable(i2c);
}
#else
if (!data->smbalert_active) {
LL_I2C_Disable(i2c);
}
#endif
k_sem_give(&data->device_sync_sem);
}
#if defined(CONFIG_I2C_TARGET)
static void stm32_i2c_slave_event(const struct device *dev)
{
const struct i2c_stm32_config *cfg = dev->config;
struct i2c_stm32_data *data = dev->data;
I2C_TypeDef *i2c = cfg->i2c;
const struct i2c_target_callbacks *slave_cb;
struct i2c_target_config *slave_cfg;
if (data->slave_cfg->flags != I2C_TARGET_FLAGS_ADDR_10_BITS) {
uint8_t slave_address;
/* Choose the right slave from the address match code */
slave_address = LL_I2C_GetAddressMatchCode(i2c) >> 1;
if (data->slave_cfg != NULL &&
slave_address == data->slave_cfg->address) {
slave_cfg = data->slave_cfg;
} else if (data->slave2_cfg != NULL &&
slave_address == data->slave2_cfg->address) {
slave_cfg = data->slave2_cfg;
} else {
__ASSERT_NO_MSG(0);
return;
}
} else {
/* On STM32 the LL_I2C_GetAddressMatchCode & (ISR register) returns
* only 7bits of address match so 10 bit dual addressing is broken.
* Revert to assuming single address match.
*/
if (data->slave_cfg != NULL) {
slave_cfg = data->slave_cfg;
} else {
__ASSERT_NO_MSG(0);
return;
}
}
slave_cb = slave_cfg->callbacks;
if (LL_I2C_IsActiveFlag_TXIS(i2c)) {
uint8_t val;
slave_cb->read_processed(slave_cfg, &val);
LL_I2C_TransmitData8(i2c, val);
return;
}
if (LL_I2C_IsActiveFlag_RXNE(i2c)) {
uint8_t val = LL_I2C_ReceiveData8(i2c);
if (slave_cb->write_received(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(slave_cfg);
/* Prepare to ACK next transmissions address byte */
LL_I2C_AcknowledgeNextData(i2c, LL_I2C_ACK);
}
if (LL_I2C_IsActiveFlag_ADDR(i2c)) {
uint32_t dir;
LL_I2C_ClearFlag_ADDR(i2c);
dir = LL_I2C_GetTransferDirection(i2c);
if (dir == LL_I2C_DIRECTION_WRITE) {
slave_cb->write_requested(slave_cfg);
LL_I2C_EnableIT_RX(i2c);
} else {
uint8_t val;
slave_cb->read_requested(slave_cfg, &val);
LL_I2C_TransmitData8(i2c, val);
LL_I2C_EnableIT_TX(i2c);
}
stm32_i2c_enable_transfer_interrupts(dev);
}
}
/* Attach and start I2C as target */
int i2c_stm32_target_register(const struct device *dev,
struct i2c_target_config *config)
{
const struct i2c_stm32_config *cfg = dev->config;
struct i2c_stm32_data *data = dev->data;
I2C_TypeDef *i2c = cfg->i2c;
uint32_t bitrate_cfg;
int ret;
if (!config) {
return -EINVAL;
}
if (data->slave_cfg && data->slave2_cfg) {
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;
}
#if defined(CONFIG_PM_DEVICE_RUNTIME)
if (pm_device_wakeup_is_capable(dev)) {
/* Mark device as active */
(void)pm_device_runtime_get(dev);
/* Enable wake-up from stop */
LOG_DBG("i2c: enabling wakeup from stop");
LL_I2C_EnableWakeUpFromStop(cfg->i2c);
}
#endif /* defined(CONFIG_PM_DEVICE_RUNTIME) */
LL_I2C_Enable(i2c);
if (!data->slave_cfg) {
data->slave_cfg = config;
if (data->slave_cfg->flags == I2C_TARGET_FLAGS_ADDR_10_BITS) {
LL_I2C_SetOwnAddress1(i2c, config->address, LL_I2C_OWNADDRESS1_10BIT);
LOG_DBG("i2c: target #1 registered with 10-bit address");
} else {
LL_I2C_SetOwnAddress1(i2c, config->address << 1U, LL_I2C_OWNADDRESS1_7BIT);
LOG_DBG("i2c: target #1 registered with 7-bit address");
}
LL_I2C_EnableOwnAddress1(i2c);
LOG_DBG("i2c: target #1 registered");
} else {
data->slave2_cfg = config;
if (data->slave2_cfg->flags == I2C_TARGET_FLAGS_ADDR_10_BITS) {
return -EINVAL;
}
LL_I2C_SetOwnAddress2(i2c, config->address << 1U,
LL_I2C_OWNADDRESS2_NOMASK);
LL_I2C_EnableOwnAddress2(i2c);
LOG_DBG("i2c: target #2 registered");
}
data->slave_attached = true;
LL_I2C_EnableIT_ADDR(i2c);
return 0;
}
int i2c_stm32_target_unregister(const struct device *dev,
struct i2c_target_config *config)
{
const struct i2c_stm32_config *cfg = dev->config;
struct i2c_stm32_data *data = dev->data;
I2C_TypeDef *i2c = cfg->i2c;
if (!data->slave_attached) {
return -EINVAL;
}
if (data->master_active) {
return -EBUSY;
}
if (config == data->slave_cfg) {
LL_I2C_DisableOwnAddress1(i2c);
data->slave_cfg = NULL;
LOG_DBG("i2c: slave #1 unregistered");
} else if (config == data->slave2_cfg) {
LL_I2C_DisableOwnAddress2(i2c);
data->slave2_cfg = NULL;
LOG_DBG("i2c: slave #2 unregistered");
} else {
return -EINVAL;
}
/* Return if there is a slave remaining */
if (data->slave_cfg || data->slave2_cfg) {
LOG_DBG("i2c: target#%c still registered", data->slave_cfg?'1':'2');
return 0;
}
/* Otherwise disable 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);
if (!data->smbalert_active) {
LL_I2C_Disable(i2c);
}
#if defined(CONFIG_PM_DEVICE_RUNTIME)
if (pm_device_wakeup_is_capable(dev)) {
/* Disable wake-up from STOP */
LOG_DBG("i2c: disabling wakeup from stop");
LL_I2C_DisableWakeUpFromStop(i2c);
/* Release the device */
(void)pm_device_runtime_put(dev);
}
#endif /* defined(CONFIG_PM_DEVICE_RUNTIME) */
data->slave_attached = false;
return 0;
}
#endif /* defined(CONFIG_I2C_TARGET) */
static void stm32_i2c_event(const struct device *dev)
{
const struct i2c_stm32_config *cfg = dev->config;
struct i2c_stm32_data *data = dev->data;
I2C_TypeDef *i2c = cfg->i2c;
#if defined(CONFIG_I2C_TARGET)
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(const struct device *dev)
{
const struct i2c_stm32_config *cfg = dev->config;
struct i2c_stm32_data *data = dev->data;
I2C_TypeDef *i2c = cfg->i2c;
#if defined(CONFIG_I2C_TARGET)
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;
}
#if defined(CONFIG_SMBUS_STM32_SMBALERT)
if (LL_I2C_IsActiveSMBusFlag_ALERT(i2c)) {
LL_I2C_ClearSMBusFlag_ALERT(i2c);
if (data->smbalert_cb_func != NULL) {
data->smbalert_cb_func(data->smbalert_cb_dev);
}
goto end;
}
#endif
return 0;
end:
stm32_i2c_master_mode_end(dev);
return -EIO;
}
#ifdef CONFIG_I2C_STM32_COMBINED_INTERRUPT
void stm32_i2c_combined_isr(void *arg)
{
const struct device *dev = (const struct device *) arg;
if (stm32_i2c_error(dev)) {
return;
}
stm32_i2c_event(dev);
}
#else
void stm32_i2c_event_isr(void *arg)
{
const struct device *dev = (const struct device *) arg;
stm32_i2c_event(dev);
}
void stm32_i2c_error_isr(void *arg)
{
const struct device *dev = (const struct device *) arg;
stm32_i2c_error(dev);
}
#endif
static int stm32_i2c_msg_write(const struct device *dev, struct i2c_msg *msg,
uint8_t *next_msg_flags, uint16_t slave)
{
const struct i2c_stm32_config *cfg = dev->config;
struct i2c_stm32_data *data = dev->data;
I2C_TypeDef *i2c = cfg->i2c;
bool is_timeout = false;
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);
if (k_sem_take(&data->device_sync_sem,
K_MSEC(STM32_I2C_TRANSFER_TIMEOUT_MSEC)) != 0) {
stm32_i2c_master_mode_end(dev);
k_sem_take(&data->device_sync_sem, K_FOREVER);
is_timeout = true;
}
if (data->current.is_nack || data->current.is_err ||
data->current.is_arlo || is_timeout) {
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;
}
if (is_timeout) {
LOG_DBG("%s: TIMEOUT", __func__);
}
return -EIO;
}
static int stm32_i2c_msg_read(const struct device *dev, struct i2c_msg *msg,
uint8_t *next_msg_flags, uint16_t slave)
{
const struct i2c_stm32_config *cfg = dev->config;
struct i2c_stm32_data *data = dev->data;
I2C_TypeDef *i2c = cfg->i2c;
bool is_timeout = false;
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);
if (k_sem_take(&data->device_sync_sem,
K_MSEC(STM32_I2C_TRANSFER_TIMEOUT_MSEC)) != 0) {
stm32_i2c_master_mode_end(dev);
k_sem_take(&data->device_sync_sem, K_FOREVER);
is_timeout = true;
}
if (data->current.is_nack || data->current.is_err ||
data->current.is_arlo || is_timeout) {
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;
}
if (is_timeout) {
LOG_DBG("%s: TIMEOUT", __func__);
}
return -EIO;
}
#else /* !CONFIG_I2C_STM32_INTERRUPT */
static inline int check_errors(const struct device *dev, const char *funcname)
{
const struct i2c_stm32_config *cfg = dev->config;
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(const struct device *dev,
unsigned int current_msg_flags)
{
const struct i2c_stm32_config *cfg = dev->config;
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;
}
static int stm32_i2c_msg_write(const struct device *dev, struct i2c_msg *msg,
uint8_t *next_msg_flags, uint16_t slave)
{
const struct i2c_stm32_config *cfg = dev->config;
I2C_TypeDef *i2c = cfg->i2c;
unsigned int len = 0U;
uint8_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);
}
static int stm32_i2c_msg_read(const struct device *dev, struct i2c_msg *msg,
uint8_t *next_msg_flags, uint16_t slave)
{
const struct i2c_stm32_config *cfg = dev->config;
I2C_TypeDef *i2c = cfg->i2c;
unsigned int len = 0U;
uint8_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(const struct device *dev, uint32_t clock)
{
const struct i2c_stm32_config *cfg = dev->config;
struct i2c_stm32_data *data = dev->data;
I2C_TypeDef *i2c = cfg->i2c;
uint32_t i2c_hold_time_min, i2c_setup_time_min;
uint32_t i2c_h_min_time, i2c_l_min_time;
uint32_t presc = 1U;
uint32_t timing = 0U;
/* Look for an adequate preset timing value */
for (uint32_t i = 0; i < cfg->n_timings; i++) {
const struct i2c_config_timing *preset = &cfg->timings[i];
uint32_t speed = i2c_map_dt_bitrate(preset->i2c_speed);
if ((I2C_SPEED_GET(speed) == I2C_SPEED_GET(data->dev_config))
&& (preset->periph_clock == clock)) {
/* Found a matching periph clock and i2c speed */
LL_I2C_SetTiming(i2c, preset->timing_setting);
return 0;
}
}
/* No preset timing was provided, let's dynamically configure */
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:
LOG_ERR("i2c: speed above \"fast\" requires manual timing configuration, "
"see \"timings\" property of st,stm32-i2c-v2 devicetree binding");
return -EINVAL;
}
/* Calculate period until prescaler matches */
do {
uint32_t t_presc = clock / presc;
uint32_t ns_presc = NSEC_PER_SEC / t_presc;
uint32_t sclh = i2c_h_min_time / ns_presc;
uint32_t scll = i2c_l_min_time / ns_presc;
uint32_t sdadel = i2c_hold_time_min / ns_presc;
uint32_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;
}
int stm32_i2c_transaction(const struct device *dev,
struct i2c_msg msg, uint8_t *next_msg_flags,
uint16_t periph)
{
/*
* Perform a I2C transaction, while taking into account the STM32 I2C V2
* peripheral has a limited maximum chunk size. Take appropriate action
* if the message to send exceeds that limit.
*
* The last chunk of a transmission uses this function's next_msg_flags
* parameter for its backend calls (_write/_read). Any previous chunks
* use a copy of the current message's flags, with the STOP and RESTART
* bits turned off. This will cause the backend to use reload-mode,
* which will make the combination of all chunks to look like one big
* transaction on the wire.
*/
const uint32_t i2c_stm32_maxchunk = 255U;
const uint8_t saved_flags = msg.flags;
uint8_t combine_flags =
saved_flags & ~(I2C_MSG_STOP | I2C_MSG_RESTART);
uint8_t *flagsp = NULL;
uint32_t rest = msg.len;
int ret = 0;
do { /* do ... while to allow zero-length transactions */
if (msg.len > i2c_stm32_maxchunk) {
msg.len = i2c_stm32_maxchunk;
msg.flags &= ~I2C_MSG_STOP;
flagsp = &combine_flags;
} else {
msg.flags = saved_flags;
flagsp = next_msg_flags;
}
if ((msg.flags & I2C_MSG_RW_MASK) == I2C_MSG_WRITE) {
ret = stm32_i2c_msg_write(dev, &msg, flagsp, periph);
} else {
ret = stm32_i2c_msg_read(dev, &msg, flagsp, periph);
}
if (ret < 0) {
break;
}
rest -= msg.len;
msg.buf += msg.len;
msg.len = rest;
} while (rest > 0U);
return ret;
}