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drivers/i2c: stm32: (FIX) add mutex to lock bus

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Add mutex to lock STM32 I2C bus in order to guarantee
that data transfers are atomic and have exclusive access
to the bus.
Issue has been found fetching data from multiple sensors
on I2C bus in a mixed context of thread and triggered
interrupt.

Signed-off-by: Armando Visconti <armando.visconti@st.com>
This commit is contained in:
Armando Visconti 2019-01-15 14:34:58 +01:00 • committed by Anas Nashif
commit ab06ec63f9
2 changed files with 17 additions and 3 deletions
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19
drivers/i2c/i2c_ll_stm32.c
View file

@ -26,6 +26,7 @@ int i2c_stm32_runtime_configure(struct device *dev, u32_t config)
struct i2c_stm32_data *data = DEV_DATA(dev);
I2C_TypeDef *i2c = cfg->i2c;
u32_t clock = 0U;
int ret;
#if defined(CONFIG_SOC_SERIES_STM32F3X) || defined(CONFIG_SOC_SERIES_STM32F0X)
LL_RCC_ClocksTypeDef rcc_clocks;
@ -44,10 +45,13 @@ int i2c_stm32_runtime_configure(struct device *dev, u32_t config)
data->dev_config = config;
k_sem_take(&data->bus_mutex, K_FOREVER);
LL_I2C_Disable(i2c);
LL_I2C_SetMode(i2c, LL_I2C_MODE_I2C);
ret = stm32_i2c_configure_timing(dev, clock);
k_sem_give(&data->bus_mutex);
return stm32_i2c_configure_timing(dev, clock);
return ret;
}
#define OPERATION(msg) (((struct i2c_msg *) msg)->flags & I2C_MSG_RW_MASK)
@ -55,6 +59,7 @@ int i2c_stm32_runtime_configure(struct device *dev, u32_t config)
static int i2c_stm32_transfer(struct device *dev, struct i2c_msg *msg,
u8_t num_msgs, u16_t slave)
{
struct i2c_stm32_data *data = DEV_DATA(dev);
#if defined(CONFIG_I2C_STM32_V1)
const struct i2c_stm32_config *cfg = DEV_CFG(dev);
I2C_TypeDef *i2c = cfg->i2c;
@ -112,6 +117,7 @@ static int i2c_stm32_transfer(struct device *dev, struct i2c_msg *msg,
}
/* Send out messages */
k_sem_take(&data->bus_mutex, K_FOREVER);
#if defined(CONFIG_I2C_STM32_V1)
LL_I2C_Enable(i2c);
#endif
@ -144,6 +150,7 @@ static int i2c_stm32_transfer(struct device *dev, struct i2c_msg *msg,
#if defined(CONFIG_I2C_STM32_V1)
LL_I2C_Disable(i2c);
#endif
k_sem_give(&data->bus_mutex);
return ret;
}
@ -162,13 +169,19 @@ static int i2c_stm32_init(struct device *dev)
const struct i2c_stm32_config *cfg = DEV_CFG(dev);
u32_t bitrate_cfg;
int ret;
#ifdef CONFIG_I2C_STM32_INTERRUPT
struct i2c_stm32_data *data = DEV_DATA(dev);
#ifdef CONFIG_I2C_STM32_INTERRUPT
k_sem_init(&data->device_sync_sem, 0, UINT_MAX);
cfg->irq_config_func(dev);
#endif
/*
* initialize mutex used when multiple transfers
* are taking place to guarantee that each one is
* atomic and has exclusive access to the I2C bus.
*/
k_sem_init(&data->bus_mutex, 1, 1);
__ASSERT_NO_MSG(clock);
if (clock_control_on(clock,
(clock_control_subsys_t *) &cfg->pclken) != 0) {

1
drivers/i2c/i2c_ll_stm32.h
View file

@ -24,6 +24,7 @@ struct i2c_stm32_data {
#ifdef CONFIG_I2C_STM32_INTERRUPT
struct k_sem device_sync_sem;
#endif
struct k_sem bus_mutex;
u32_t dev_config;
#ifdef CONFIG_I2C_STM32_V1
u16_t slave_address;