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Merge pull request #2323 from thomaseichinger/i2c_mutex

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periph/i2c: added means to make I2C thread-safe
This commit is contained in:
Peter Kietzmann 2015-01-20 07:57:20 +01:00
commit ebadbd6da3
5 changed files with 174 additions and 1 deletions
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38
cpu/samd21/periph/i2c.c
View File

@ -12,6 +12,7 @@
* @file
* @brief Low-level I2C driver implementation
* @author Baptiste Clenet <baptiste.clenet@xsoen.com>
* @author Thomas Eichinger <thomas.eichinger@fu-berlin.de>
* @}
*/
@ -19,7 +20,7 @@
#include "cpu.h"
#include "board.h"
#include "mutex.h"
#include "periph_conf.h"
#include "periph/i2c.h"
#include "instance/instance_sercom3.h"
@ -41,6 +42,23 @@ static inline void _write(SercomI2cm *dev, char *data, int length);
static inline void _read(SercomI2cm *dev, char *data, int length);
static inline void _stop(SercomI2cm *dev);
/**
* @brief Array holding one pre-initialized mutex for each I2C device
*/
static mutex_t locks[] = {
#if I2C_0_EN
[I2C_0] = MUTEX_INIT,
#endif
#if I2C_1_EN
[I2C_1] = MUTEX_INIT,
#endif
#if I2C_2_EN
[I2C_2] = MUTEX_INIT
#endif
#if I2C_3_EN
[I2C_3] = MUTEX_INIT
#endif
};
int i2c_init_master(i2c_t dev, i2c_speed_t speed)
{
@ -191,6 +209,24 @@ int i2c_init_slave(i2c_t dev, uint8_t address)
return 0;
}
int i2c_acquire(i2c_t dev)
{
if (dev >= I2C_NUMOF) {
return -1;
}
mutex_lock(&locks[dev]);
return 0;
}
int i2c_release(i2c_t dev)
{
if (dev >= I2C_NUMOF) {
return -1;
}
mutex_unlock(&locks[dev]);
return 0;
}
int i2c_read_byte(i2c_t dev, uint8_t address, char *data)
{
return i2c_read_bytes(dev, address, data, 1);

39
cpu/stm32f1/periph/i2c.c
View File

@ -18,6 +18,7 @@
* For implementation details please refer to STM application note AN2824.
*
* @author Hauke Petersen <hauke.petersen@fu-berlin.de>
* @author Thomas Eichinger <thomas.eichinger@fu-berlin.de>
*
* @}
*/
@ -26,6 +27,7 @@
#include "cpu.h"
#include "irq.h"
#include "mutex.h"
#include "periph_conf.h"
#include "periph/i2c.h"
@ -44,6 +46,24 @@ static inline void _clear_addr(I2C_TypeDef *dev);
static inline void _write(I2C_TypeDef *dev, char *data, int length);
static inline void _stop(I2C_TypeDef *dev);
/**
* @brief Array holding one pre-initialized mutex for each I2C device
*/
static mutex_t locks[] = {
#if I2C_0_EN
[I2C_0] = MUTEX_INIT,
#endif
#if I2C_1_EN
[I2C_1] = MUTEX_INIT,
#endif
#if I2C_2_EN
[I2C_2] = MUTEX_INIT
#endif
#if I2C_3_EN
[I2C_3] = MUTEX_INIT
#endif
};
int i2c_init_master(i2c_t dev, i2c_speed_t speed)
{
I2C_TypeDef *i2c;
@ -105,6 +125,7 @@ int i2c_init_master(i2c_t dev, i2c_speed_t speed)
/* enable device */
_i2c_init(i2c, ccr);
}
return 0;
}
@ -173,6 +194,24 @@ int i2c_init_slave(i2c_t dev, uint8_t address)
return -1;
}
int i2c_acquire(i2c_t dev)
{
if (dev >= I2C_NUMOF) {
return -1;
}
mutex_lock(&locks[dev]);
return 0;
}
int i2c_release(i2c_t dev)
{
if (dev >= I2C_NUMOF) {
return -1;
}
mutex_unlock(&locks[dev]);
return 0;
}
int i2c_read_byte(i2c_t dev, uint8_t address, char *data)
{
return i2c_read_bytes(dev, address, data, 1);

38
cpu/stm32f4/periph/i2c.c
View File

@ -17,6 +17,7 @@
*
* @author Peter Kietzmann <peter.kietzmann@haw-hamburg.de>
* @author Hauke Petersen <hauke.petersen@fu-berlin.de>
* @auhtor Thomas Eichinge <thomas.eichinger@fu-berlin.de>
*
* @}
*/
@ -25,6 +26,7 @@
#include "cpu.h"
#include "irq.h"
#include "mutex.h"
#include "periph_conf.h"
#include "periph/i2c.h"
@ -43,6 +45,24 @@ static inline void _clear_addr(I2C_TypeDef *dev);
static inline void _write(I2C_TypeDef *dev, char *data, int length);
static inline void _stop(I2C_TypeDef *dev);
/**
* @brief Array holding one pre-initialized mutex for each I2C device
*/
static mutex_t locks[] = {
#if I2C_0_EN
[I2C_0] = MUTEX_INIT,
#endif
#if I2C_1_EN
[I2C_1] = MUTEX_INIT,
#endif
#if I2C_2_EN
[I2C_2] = MUTEX_INIT
#endif
#if I2C_3_EN
[I2C_3] = MUTEX_INIT
#endif
};
int i2c_init_master(i2c_t dev, i2c_speed_t speed)
{
I2C_TypeDef *i2c;
@ -201,6 +221,24 @@ int i2c_init_slave(i2c_t dev, uint8_t address)
return -1;
}
int i2c_acquire(i2c_t dev)
{
if (dev >= I2C_NUMOF) {
return -1;
}
mutex_lock(&locks[dev]);
return 0;
}
int i2c_release(i2c_t dev)
{
if (dev >= I2C_NUMOF) {
return -1;
}
mutex_unlock(&locks[dev]);
return 0;
}
int i2c_read_byte(i2c_t dev, uint8_t address, char *data)
{
return i2c_read_bytes(dev, address, data, 1);

37
cpu/stm32l1/periph/i2c.c
View File

@ -26,6 +26,7 @@
#include "cpu.h"
#include "mutex.h"
#include "periph/i2c.h"
#include "periph_conf.h"
@ -45,6 +46,24 @@ static inline void _clear_addr(I2C_TypeDef *dev);
static inline void _write(I2C_TypeDef *dev, char *data, int length);
static inline void _stop(I2C_TypeDef *dev);
/**
* @brief Array holding one pre-initialized mutex for each I2C device
*/
static mutex_t locks[] = {
#if I2C_0_EN
[I2C_0] = MUTEX_INIT,
#endif
#if I2C_1_EN
[I2C_1] = MUTEX_INIT,
#endif
#if I2C_2_EN
[I2C_2] = MUTEX_INIT
#endif
#if I2C_3_EN
[I2C_3] = MUTEX_INIT
#endif
};
int i2c_init_master(i2c_t dev, i2c_speed_t speed)
{
I2C_TypeDef *i2c;
@ -200,6 +219,24 @@ int i2c_init_slave(i2c_t dev, uint8_t address)
return -1;
}
int i2c_acquire(i2c_t dev)
{
if (dev >= I2C_NUMOF) {
return -1;
}
mutex_lock(&locks[dev]);
return 0;
}
int i2c_release(i2c_t dev)
{
if (dev >= I2C_NUMOF) {
return -1;
}
mutex_unlock(&locks[dev]);
return 0;
}
int i2c_read_byte(i2c_t dev, uint8_t address, char *data)
{
return i2c_read_bytes(dev, address, data, 1);

23
drivers/include/periph/i2c.h
View File

@ -46,6 +46,7 @@
7-bit addressing mode.
*
* @author Hauke Petersen <hauke.petersen@fu-berlin.de>
* @author Thomas Eichinger <thomas.eichinger@fu-berlin.de>
*/
#ifndef __I2C_H
@ -119,6 +120,28 @@ int i2c_init_master(i2c_t dev, i2c_speed_t speed);
*/
int i2c_init_slave(i2c_t dev, uint8_t address);
/**
* @brief Get mutually exclusive access to the given I2C bus
*
* In case the I2C device is busy, this function will block until the bus is free again.
*
* @param[in] dev I2C device to access
*
* @return 0 on success
* @return -1 on error
*/
int i2c_acquire(i2c_t dev);
/**
* @brief Release the given I2C device to be used by others
*
* @param[in] dev I2C device to release
*
* @return 0 on success
* @return -1 on error
*/
int i2c_release(i2c_t dev);
/**
* @brief Read one byte from an I2C device with the given address
*