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cpu/stm32_common: add timeouts in stm32f4 i2c driver

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This commit is contained in:
Vincent Dupont 2018-06-01 10:59:42 +02:00 committed by dylad
parent e90f2b439e
commit c0c9ea034c
1 changed files with 55 additions and 16 deletions
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71
cpu/stm32_common/periph/i2c_2.c
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@ -52,11 +52,13 @@
#define TICK_TIMEOUT (0xFFFF)
#define ERROR_FLAG (I2C_SR1_AF | I2C_SR1_ARLO | I2C_SR1_BERR)
/* static function definitions */
static void _i2c_init(I2C_TypeDef *i2c, uint32_t clk, uint32_t ccr);
static void _start(I2C_TypeDef *dev, uint8_t address, uint8_t rw_flag, uint8_t flags);
static inline void _clear_addr(I2C_TypeDef *dev);
static inline void _write(I2C_TypeDef *dev, const uint8_t *data, int length);
static inline int _write(I2C_TypeDef *dev, const uint8_t *data, int length);
static inline void _stop(I2C_TypeDef *dev);
static inline int _wait_ready(I2C_TypeDef *dev);
@ -163,6 +165,8 @@ static void _i2c_init(I2C_TypeDef *i2c, uint32_t clk, uint32_t ccr)
/* configure device */
i2c->OAR1 |= (1 << 14); /* datasheet: bit 14 should be kept 1 */
i2c->OAR1 &= ~I2C_OAR1_ADDMODE; /* make sure we are in 7-bit address mode */
/* Clear flags */
i2c->SR1 &= ~ERROR_FLAG;
/* enable device */
i2c->CR1 |= I2C_CR1_PE;
}
@ -205,6 +209,7 @@ int i2c_read_bytes(i2c_t dev, uint16_t address, void *data, size_t length,
uint8_t flags)
{
assert(dev < I2C_NUMOF);
uint16_t tick = TICK_TIMEOUT;
size_t n = length;
char *in = (char *)data;
@ -230,7 +235,12 @@ int i2c_read_bytes(i2c_t dev, uint16_t address, void *data, size_t length,
while (n--) {
/* wait for reception to complete */
while (!(i2c->SR1 & I2C_SR1_RXNE)) {}
while (!(i2c->SR1 & I2C_SR1_RXNE)) {
if ((i2c->SR1 & ERROR_FLAG) || !tick) {
length = 0;
break;
}
}
if (n == 1) {
/* disable ACK */
@ -255,6 +265,7 @@ int i2c_read_regs(i2c_t dev, uint16_t address, uint16_t reg, void *data,
size_t length, uint8_t flags)
{
assert(dev < I2C_NUMOF);
uint16_t tick = TICK_TIMEOUT;
I2C_TypeDef *i2c = i2c_config[dev].dev;
assert(i2c != NULL);
@ -270,9 +281,18 @@ int i2c_read_regs(i2c_t dev, uint16_t address, uint16_t reg, void *data,
_start(i2c, address, I2C_FLAG_WRITE, flags);
DEBUG("[i2c] read_regs: Write reg into DR\n");
_clear_addr(i2c);
while (!(i2c->SR1 & I2C_SR1_TXE)) {}
while (!(i2c->SR1 & I2C_SR1_TXE) && tick--) {
if ((i2c->SR1 & ERROR_FLAG) || !tick) {
break;
}
}
i2c->DR = reg;
while (!(i2c->SR1 & I2C_SR1_TXE)) {}
tick = TICK_TIMEOUT;
while (!(i2c->SR1 & I2C_SR1_TXE) && tick--) {
if ((i2c->SR1 & ERROR_FLAG) || !tick) {
break;
}
}
DEBUG("[i2c] read_regs: Now start a read transaction\n");
return i2c_read_bytes(dev, address, data, length, flags);
}
@ -298,7 +318,9 @@ int i2c_write_bytes(i2c_t dev, uint16_t address, const void *data,
_clear_addr(i2c);
/* send out data bytes */
_write(i2c, data, length);
if (_write(i2c, data, length) < 0) {
length = 0;
}
if (!(flags & I2C_NOSTOP)) {
/* end transmission */
DEBUG("[i2c] write_bytes: Ending transmission\n");
@ -326,9 +348,13 @@ int i2c_write_regs(i2c_t dev, uint16_t address, uint16_t reg, const void *data,
_start(i2c, address, I2C_FLAG_WRITE, flags);
_clear_addr(i2c);
/* send register address and wait for complete transfer to be finished*/
_write(i2c, (uint8_t *)&reg, 1);
if (_write(i2c, (uint8_t *)&reg, 1) < 0) {
length = 0;
}
/* write data to register */
_write(i2c, data, length);
else if (_write(i2c, data, length) < 0) {
length = 0;
}
/* finish transfer */
_stop(i2c);
/* return number of bytes send */
@ -338,7 +364,9 @@ int i2c_write_regs(i2c_t dev, uint16_t address, uint16_t reg, const void *data,
static void _start(I2C_TypeDef *i2c, uint8_t address, uint8_t rw_flag, uint8_t flags)
{
(void)flags;
start:
/* Clear flags */
i2c->SR1 &= ~ERROR_FLAG;
/* generate start condition */
i2c->CR1 |= I2C_CR1_START;
@ -349,12 +377,11 @@ start:
/* send address and read/write flag */
i2c->DR = (address << 1) | rw_flag;
uint16_t tick = TICK_TIMEOUT;
/* Wait for ADDR flag to be set */
while (!(i2c->SR1 & I2C_SR1_ADDR)) {
if (i2c->SR1 & I2C_SR1_AF) {
/* if the device answers NACK on sending the address, retry */
i2c->SR1 &= ~(I2C_SR1_AF);
goto start;
while (!(i2c->SR1 & I2C_SR1_ADDR) && tick--) {
if ((i2c->SR1 & ERROR_FLAG) || !tick) {
return;
}
}
}
@ -365,7 +392,7 @@ static inline void _clear_addr(I2C_TypeDef *i2c)
i2c->SR2;
}
static inline void _write(I2C_TypeDef *i2c, const uint8_t *data, int length)
static inline int _write(I2C_TypeDef *i2c, const uint8_t *data, int length)
{
DEBUG("[i2c] write: Looping through bytes\n");
@ -375,19 +402,31 @@ static inline void _write(I2C_TypeDef *i2c, const uint8_t *data, int length)
DEBUG("[i2c] write: Written %i byte to data reg, now waiting for DR "
"to be empty again\n", i);
uint16_t tick = TICK_TIMEOUT;
/* wait for transfer to finish */
while (!(i2c->SR1 & I2C_SR1_TXE)) {}
while (!(i2c->SR1 & I2C_SR1_TXE) && tick--) {
if ((i2c->SR1 & ERROR_FLAG) || !tick) {
return -1;
}
}
DEBUG("[i2c] write: DR is now empty again\n");
}
return 0;
}
static inline void _stop(I2C_TypeDef *i2c)
{
uint16_t tick = TICK_TIMEOUT;
/* make sure last byte was send */
DEBUG("[i2c] write: Wait if last byte hasn't been sent\n");
while (!(i2c->SR1 & I2C_SR1_BTF)) {}
while (!(i2c->SR1 & I2C_SR1_BTF) && tick--) {
if ((i2c->SR1 & ERROR_FLAG) || !tick) {
break;
}
}
/* send STOP condition */
i2c->CR1 |= I2C_CR1_STOP;