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Merge pull request #3751 from daniel-k/pr/samd21_i2c

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samd21/i2c: add feedback in case transfer failed
This commit is contained in:
Peter Kietzmann 2015-09-29 20:14:43 +02:00
commit d081adeda9
1 changed files with 26 additions and 23 deletions
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49
cpu/samd21/periph/i2c.c
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@ -37,9 +37,9 @@
#define SAMD21_I2C_TIMEOUT (65535)
/* static function definitions */
static inline void _start(SercomI2cm *dev, uint8_t address, uint8_t rw_flag);
static inline void _write(SercomI2cm *dev, char *data, int length);
static inline void _read(SercomI2cm *dev, char *data, int length);
static inline int _start(SercomI2cm *dev, uint8_t address, uint8_t rw_flag);
static inline int _write(SercomI2cm *dev, char *data, int length);
static inline int _read(SercomI2cm *dev, char *data, int length);
static inline void _stop(SercomI2cm *dev);
/**
@ -248,9 +248,9 @@ int i2c_read_bytes(i2c_t dev, uint8_t address, char *data, int length)
}
/* start transmission and send slave address */
_start(i2c, address, I2C_FLAG_READ);
if(_start(i2c, address, I2C_FLAG_READ) < 0) return 0;
/* read data to register */
_read(i2c, data, length);
if(_read(i2c, data, length) < 0) return 0;
_stop(i2c);
/* return number of bytes sent */
return length;
@ -276,10 +276,10 @@ int i2c_read_regs(i2c_t dev, uint8_t address, uint8_t reg, char *data, int lengt
}
/* start transmission and send slave address */
_start(i2c, address, I2C_FLAG_WRITE);
if(_start(i2c, address, I2C_FLAG_WRITE) < 0) return 0;
/* send register address/command and wait for complete transfer to
* be finished */
_write(i2c, (char *)(&reg), 1);
if(_write(i2c, (char *)(&reg), 1) < 0) return 0;
return i2c_read_bytes(dev, address, data, length);
}
@ -302,8 +302,8 @@ int i2c_write_bytes(i2c_t dev, uint8_t address, char *data, int length)
return -1;
}
_start(I2CSercom, address, I2C_FLAG_WRITE);
_write(I2CSercom, data, length);
if(_start(I2CSercom, address, I2C_FLAG_WRITE) < 0) return 0;
if(_write(I2CSercom, data, length) < 0) return 0;
_stop(I2CSercom);
return length;
}
@ -329,11 +329,11 @@ int i2c_write_regs(i2c_t dev, uint8_t address, uint8_t reg, char *data, int leng
}
/* start transmission and send slave address */
_start(i2c, address, I2C_FLAG_WRITE);
if(_start(i2c, address, I2C_FLAG_WRITE) < 0) return 0;
/* send register address and wait for complete transfer to be finished */
_write(i2c, (char *)(&reg), 1);
if(_write(i2c, (char *)(&reg), 1) < 0) return 0;
/* write data to register */
_write(i2c, data, length);
if(_write(i2c, data, length) < 0) return 0;
/* finish transfer */
_stop(i2c);
return length;
@ -367,7 +367,7 @@ void i2c_poweroff(i2c_t dev)
}
}
static void _start(SercomI2cm *dev, uint8_t address, uint8_t rw_flag)
static int _start(SercomI2cm *dev, uint8_t address, uint8_t rw_flag)
{
uint32_t timeout_counter = 0;
@ -387,7 +387,7 @@ static void _start(SercomI2cm *dev, uint8_t address, uint8_t rw_flag)
&& !(dev->INTFLAG.reg & SERCOM_I2CM_INTFLAG_SB)) {
if (++timeout_counter >= SAMD21_I2C_TIMEOUT) {
DEBUG("STATUS_ERR_TIMEOUT\n");
return;
return -1;
}
}
@ -400,7 +400,7 @@ static void _start(SercomI2cm *dev, uint8_t address, uint8_t rw_flag)
/* Check arbitration. */
if (dev->STATUS.reg & SERCOM_I2CM_STATUS_ARBLOST) {
DEBUG("STATUS_ERR_PACKET_COLLISION\n");
return;
return -2;
}
}
/* Check that slave responded with ack. */
@ -408,11 +408,12 @@ static void _start(SercomI2cm *dev, uint8_t address, uint8_t rw_flag)
/* Slave busy. Issue ack and stop command. */
dev->CTRLB.reg |= SERCOM_I2CM_CTRLB_CMD(3);
DEBUG("STATUS_ERR_BAD_ADDRESS\n");
return;
return -3;
}
return 0;
}
static inline void _write(SercomI2cm *dev, char *data, int length)
static inline int _write(SercomI2cm *dev, char *data, int length)
{
uint16_t tmp_data_length = length;
uint32_t timeout_counter = 0;
@ -424,7 +425,7 @@ static inline void _write(SercomI2cm *dev, char *data, int length)
/* Check that bus ownership is not lost. */
if (!(dev->STATUS.reg & SERCOM_I2CM_STATUS_BUSSTATE(2))) {
DEBUG("STATUS_ERR_PACKET_COLLISION\n");
return;
return -2;
}
/* Wait for hardware module to sync */
@ -438,19 +439,20 @@ static inline void _write(SercomI2cm *dev, char *data, int length)
&& !(dev->INTFLAG.reg & SERCOM_I2CM_INTFLAG_SB)) {
if (++timeout_counter >= SAMD21_I2C_TIMEOUT) {
DEBUG("STATUS_ERR_TIMEOUT\n");
return;
return -1;
}
}
/* Check for NACK from slave. */
if (dev->STATUS.reg & SERCOM_I2CM_STATUS_RXNACK) {
DEBUG("STATUS_ERR_OVERFLOW\n");
return;
return -4;
}
}
return 0;
}
static inline void _read(SercomI2cm *dev, char *data, int length)
static inline int _read(SercomI2cm *dev, char *data, int length)
{
uint32_t timeout_counter = 0;
uint8_t count = 0;
@ -463,7 +465,7 @@ static inline void _read(SercomI2cm *dev, char *data, int length)
/* Check that bus ownership is not lost. */
if (!(dev->STATUS.reg & SERCOM_I2CM_STATUS_BUSSTATE(2))) {
DEBUG("STATUS_ERR_PACKET_COLLISION\n");
return;
return -2;
}
/* Wait for hardware module to sync */
@ -477,13 +479,14 @@ static inline void _read(SercomI2cm *dev, char *data, int length)
&& !(dev->INTFLAG.reg & SERCOM_I2CM_INTFLAG_SB)) {
if (++timeout_counter >= SAMD21_I2C_TIMEOUT) {
DEBUG("STATUS_ERR_TIMEOUT\n");
return;
return -1;
}
}
count++;
}
/* Send NACK before STOP */
dev->CTRLB.reg |= SERCOM_I2CM_CTRLB_ACKACT;
return 0;
}
static inline void _stop(SercomI2cm *dev)