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samd21: i2c: improve busstate comparison

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This commit is contained in:
Michael Andersen 2016-09-08 17:50:09 -07:00
parent 5552b92023
commit e367ab93f6
1 changed files with 10 additions and 5 deletions
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15
cpu/samd21/periph/i2c.c
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@ -35,6 +35,11 @@
#define SAMD21_I2C_TIMEOUT (65535)
#define BUSSTATE_UNKNOWN SERCOM_I2CM_STATUS_BUSSTATE(0)
#define BUSSTATE_IDLE SERCOM_I2CM_STATUS_BUSSTATE(1)
#define BUSSTATE_OWNER SERCOM_I2CM_STATUS_BUSSTATE(2)
#define BUSSTATE_BUSY SERCOM_I2CM_STATUS_BUSSTATE(3)
/* static function definitions */
static void _i2c_poweron(SercomI2cm *sercom);
static void _i2c_poweroff(SercomI2cm *sercom);
@ -197,10 +202,10 @@ int i2c_init_master(i2c_t dev, i2c_speed_t speed)
i2c_poweron(dev);
/* Start timeout if bus state is unknown. */
while (!(I2CSercom->STATUS.reg & SERCOM_I2CM_STATUS_BUSSTATE(1))) {
while ((I2CSercom->STATUS.reg & SERCOM_I2CM_STATUS_BUSSTATE_Msk) == BUSSTATE_UNKNOWN) {
if(timeout_counter++ >= SAMD21_I2C_TIMEOUT) {
/* Timeout, force bus state to idle. */
I2CSercom->STATUS.reg = SERCOM_I2CM_STATUS_BUSSTATE(1);
I2CSercom->STATUS.reg = BUSSTATE_IDLE;
}
}
return 0;
@ -435,7 +440,7 @@ static inline int _write(SercomI2cm *dev, char *data, int length)
DEBUG("Looping through bytes\n");
while (tmp_data_length--) {
/* Check that bus ownership is not lost. */
if (!(dev->STATUS.reg & SERCOM_I2CM_STATUS_BUSSTATE(2))) {
if ((dev->STATUS.reg & SERCOM_I2CM_STATUS_BUSSTATE_Msk) != BUSSTATE_OWNER) {
DEBUG("STATUS_ERR_PACKET_COLLISION\n");
return -2;
}
@ -475,7 +480,7 @@ static inline int _read(SercomI2cm *dev, char *data, int length)
/* Read data buffer. */
while (count != length) {
/* Check that bus ownership is not lost. */
if (!(dev->STATUS.reg & SERCOM_I2CM_STATUS_BUSSTATE(2))) {
if ((dev->STATUS.reg & SERCOM_I2CM_STATUS_BUSSTATE_Msk) != BUSSTATE_OWNER) {
DEBUG("STATUS_ERR_PACKET_COLLISION\n");
return -2;
}
@ -508,7 +513,7 @@ static inline void _stop(SercomI2cm *dev)
/* Stop command */
dev->CTRLB.reg |= SERCOM_I2CM_CTRLB_CMD(3);
/* Wait for bus to be idle again */
while(dev->STATUS.reg & SERCOM_I2CM_STATUS_BUSSTATE(1)) {}
while((dev->STATUS.reg & SERCOM_I2CM_STATUS_BUSSTATE_Msk) != BUSSTATE_IDLE) {}
DEBUG("Stop sent\n");
}