diff options
Diffstat (limited to 'drivers/avr/i2c_master.c')
-rwxr-xr-x | drivers/avr/i2c_master.c | 133 |
1 files changed, 82 insertions, 51 deletions
diff --git a/drivers/avr/i2c_master.c b/drivers/avr/i2c_master.c index caca2179e0..30ea760c9f 100755 --- a/drivers/avr/i2c_master.c +++ b/drivers/avr/i2c_master.c @@ -19,7 +19,7 @@ void i2c_init(void) //TWBR = 10; } -i2c_status_t i2c_start(uint8_t address, uint8_t timeout) +i2c_status_t i2c_start(uint8_t address, uint16_t timeout) { // reset TWI control register TWCR = 0; @@ -28,13 +28,13 @@ i2c_status_t i2c_start(uint8_t address, uint8_t timeout) uint16_t timeout_timer = timer_read(); while( !(TWCR & (1<<TWINT)) ) { - if (timeout && (timer_read() - timeout_timer) > timeout) { + if (timeout && ((timer_read() - timeout_timer) > timeout)) { return I2C_STATUS_TIMEOUT; } } // check if the start condition was successfully transmitted - if(((TW_STATUS & 0xF8) != TW_START) && ((TW_STATUS & 0xF8) != TW_REP_START)){ return 1; } + if(((TW_STATUS & 0xF8) != TW_START) && ((TW_STATUS & 0xF8) != TW_REP_START)){ return I2C_STATUS_ERROR; } // load slave address into data register TWDR = address; @@ -43,19 +43,19 @@ i2c_status_t i2c_start(uint8_t address, uint8_t timeout) timeout_timer = timer_read(); while( !(TWCR & (1<<TWINT)) ) { - if (timeout && (timer_read() - timeout_timer) > I2C_TIMEOUT) { + if (timeout && ((timer_read() - timeout_timer) > timeout)) { return I2C_STATUS_TIMEOUT; } } // check if the device has acknowledged the READ / WRITE mode uint8_t twst = TW_STATUS & 0xF8; - if ( (twst != TW_MT_SLA_ACK) && (twst != TW_MR_SLA_ACK) ) return 1; + if ( (twst != TW_MT_SLA_ACK) && (twst != TW_MR_SLA_ACK) ) return I2C_STATUS_ERROR; - return 0; + return I2C_STATUS_SUCCESS; } -i2c_status_t i2c_write(uint8_t data, uint8_t timeout) +i2c_status_t i2c_write(uint8_t data, uint16_t timeout) { // load data into data register TWDR = data; @@ -64,17 +64,17 @@ i2c_status_t i2c_write(uint8_t data, uint8_t timeout) uint16_t timeout_timer = timer_read(); while( !(TWCR & (1<<TWINT)) ) { - if (timeout && (timer_read() - timeout_timer) > I2C_TIMEOUT) { + if (timeout && ((timer_read() - timeout_timer) > timeout)) { return I2C_STATUS_TIMEOUT; } } - if( (TW_STATUS & 0xF8) != TW_MT_DATA_ACK ){ return 1; } + if( (TW_STATUS & 0xF8) != TW_MT_DATA_ACK ){ return I2C_STATUS_ERROR; } - return 0; + return I2C_STATUS_SUCCESS; } -i2c_status_t i2c_read_ack(uint8_t timeout) +int16_t i2c_read_ack(uint16_t timeout) { // start TWI module and acknowledge data after reception @@ -82,7 +82,7 @@ i2c_status_t i2c_read_ack(uint8_t timeout) uint16_t timeout_timer = timer_read(); while( !(TWCR & (1<<TWINT)) ) { - if (timeout && (timer_read() - timeout_timer) > I2C_TIMEOUT) { + if (timeout && ((timer_read() - timeout_timer) > timeout)) { return I2C_STATUS_TIMEOUT; } } @@ -91,7 +91,7 @@ i2c_status_t i2c_read_ack(uint8_t timeout) return TWDR; } -i2c_status_t i2c_read_nack(uint8_t timeout) +int16_t i2c_read_nack(uint16_t timeout) { // start receiving without acknowledging reception @@ -99,7 +99,7 @@ i2c_status_t i2c_read_nack(uint8_t timeout) uint16_t timeout_timer = timer_read(); while( !(TWCR & (1<<TWINT)) ) { - if (timeout && (timer_read() - timeout_timer) > I2C_TIMEOUT) { + if (timeout && ((timer_read() - timeout_timer) > timeout)) { return I2C_STATUS_TIMEOUT; } } @@ -108,81 +108,112 @@ i2c_status_t i2c_read_nack(uint8_t timeout) return TWDR; } -i2c_status_t i2c_transmit(uint8_t address, uint8_t* data, uint16_t length) +i2c_status_t i2c_transmit(uint8_t address, uint8_t* data, uint16_t length, uint16_t timeout) { - if (i2c_start(address | I2C_WRITE)) return 1; + i2c_status_t status = i2c_start(address | I2C_WRITE, timeout); + if (status) return status; - for (uint16_t i = 0; i < length; i++) - { - if (i2c_write(data[i])) return 1; + for (uint16_t i = 0; i < length; i++) { + status = i2c_write(data[i], timeout); + if (status) return status; } - i2c_stop(); + status = i2c_stop(timeout); + if (status) return status; - return 0; + return I2C_STATUS_SUCCESS; } -uint8_t i2c_receive(uint8_t address, uint8_t* data, uint16_t length) +i2c_status_t i2c_receive(uint8_t address, uint8_t* data, uint16_t length, uint16_t timeout) { - if (i2c_start(address | I2C_READ)) return 1; - - for (uint16_t i = 0; i < (length-1); i++) - { - data[i] = i2c_read_ack(); + i2c_status_t status = i2c_start(address | I2C_READ, timeout); + if (status) return status; + + for (uint16_t i = 0; i < (length-1); i++) { + status = i2c_read_ack(timeout); + if (status >= 0) { + data[i] = status; + } else { + return status; + } } - data[(length-1)] = i2c_read_nack(); - i2c_stop(); + status = i2c_read_nack(timeout); + if (status >= 0 ) { + data[(length-1)] = status; + } else { + return status; + } + + status = i2c_stop(timeout); + if (status) return status; - return 0; + return I2C_STATUS_SUCCESS; } -uint8_t i2c_writeReg(uint8_t devaddr, uint8_t regaddr, uint8_t* data, uint16_t length) +i2c_status_t i2c_writeReg(uint8_t devaddr, uint8_t regaddr, uint8_t* data, uint16_t length, uint16_t timeout) { - if (i2c_start(devaddr | 0x00)) return 1; + i2c_status_t status = i2c_start(devaddr | 0x00, timeout); + if (status) return status; - i2c_write(regaddr); + status = i2c_write(regaddr, timeout); + if (status) return status; - for (uint16_t i = 0; i < length; i++) - { - if (i2c_write(data[i])) return 1; + for (uint16_t i = 0; i < length; i++) { + status = i2c_write(data[i], timeout); + if (status) return status; } - i2c_stop(); + status = i2c_stop(timeout); + if (status) return status; - return 0; + return I2C_STATUS_SUCCESS; } -uint8_t i2c_readReg(uint8_t devaddr, uint8_t regaddr, uint8_t* data, uint16_t length) +i2c_status_t i2c_readReg(uint8_t devaddr, uint8_t regaddr, uint8_t* data, uint16_t length, uint16_t timeout) { - if (i2c_start(devaddr)) return 1; + i2c_status_t status = i2c_start(devaddr, timeout); + if (status) return status; - i2c_write(regaddr); + status = i2c_write(regaddr, timeout); + if (status) return status; - if (i2c_start(devaddr | 0x01)) return 1; + status = i2c_start(devaddr | 0x01, timeout); + if (status) return status; - for (uint16_t i = 0; i < (length-1); i++) - { - data[i] = i2c_read_ack(); + for (uint16_t i = 0; i < (length-1); i++) { + status = i2c_read_ack(timeout); + if (status >= 0) { + data[i] = status; + } else { + return status; + } } - data[(length-1)] = i2c_read_nack(); - i2c_stop(); + status = i2c_read_nack(timeout); + if (status >= 0 ) { + data[(length-1)] = status; + } else { + return status; + } + + status = i2c_stop(timeout); + if (status) return status; - return 0; + return I2C_STATUS_SUCCESS; } -i2c_status_t i2c_stop(uint8_t timeout) +i2c_status_t i2c_stop(uint16_t timeout) { // transmit STOP condition TWCR = (1<<TWINT) | (1<<TWEN) | (1<<TWSTO); uint16_t timeout_timer = timer_read(); while(TWCR & (1<<TWSTO)) { - if (timeout && (timer_read() - timeout_timer) > I2C_TIMEOUT) { + if (timeout && ((timer_read() - timeout_timer) > timeout)) { return I2C_STATUS_TIMEOUT; } } - return 0; + return I2C_STATUS_SUCCESS; } |