diff options
Diffstat (limited to 'drivers/avr')
| -rwxr-xr-x | drivers/avr/i2c_master.c | 102 | ||||
| -rwxr-xr-x | drivers/avr/i2c_master.h | 15 |
2 files changed, 46 insertions, 71 deletions
diff --git a/drivers/avr/i2c_master.c b/drivers/avr/i2c_master.c index 97f6900436..caca2179e0 100755 --- a/drivers/avr/i2c_master.c +++ b/drivers/avr/i2c_master.c @@ -19,24 +19,19 @@ void i2c_init(void) //TWBR = 10; } -uint8_t i2c_start(uint8_t address) +i2c_status_t i2c_start(uint8_t address, uint8_t timeout) { // reset TWI control register TWCR = 0; // transmit START condition TWCR = (1<<TWINT) | (1<<TWSTA) | (1<<TWEN); - #ifdef I2C_TIMEOUT - uint16_t timeout_timer = timer_read(); - while( !(TWCR & (1<<TWINT)) ) { - if ((timer_read() - timeout_timer) > I2C_TIMEOUT) { - return 2; // should make these codes standard - } + uint16_t timeout_timer = timer_read(); + while( !(TWCR & (1<<TWINT)) ) { + if (timeout && (timer_read() - timeout_timer) > timeout) { + return I2C_STATUS_TIMEOUT; } - #else - // wait for end of transmission - while( !(TWCR & (1<<TWINT)) ); - #endif + } // check if the start condition was successfully transmitted if(((TW_STATUS & 0xF8) != TW_START) && ((TW_STATUS & 0xF8) != TW_REP_START)){ return 1; } @@ -46,17 +41,12 @@ uint8_t i2c_start(uint8_t address) // start transmission of address TWCR = (1<<TWINT) | (1<<TWEN); - #ifdef I2C_TIMEOUT - timeout_timer = timer_read(); - while( !(TWCR & (1<<TWINT)) ) { - if ((timer_read() - timeout_timer) > I2C_TIMEOUT) { - return 2; // should make these codes standard - } + timeout_timer = timer_read(); + while( !(TWCR & (1<<TWINT)) ) { + if (timeout && (timer_read() - timeout_timer) > I2C_TIMEOUT) { + return I2C_STATUS_TIMEOUT; } - #else - // wait for end of transmission - while( !(TWCR & (1<<TWINT)) ); - #endif + } // check if the device has acknowledged the READ / WRITE mode uint8_t twst = TW_STATUS & 0xF8; @@ -65,75 +55,60 @@ uint8_t i2c_start(uint8_t address) return 0; } -uint8_t i2c_write(uint8_t data) +i2c_status_t i2c_write(uint8_t data, uint8_t timeout) { // load data into data register TWDR = data; // start transmission of data TWCR = (1<<TWINT) | (1<<TWEN); - #ifdef I2C_TIMEOUT - uint16_t timeout_timer = timer_read(); - while( !(TWCR & (1<<TWINT)) ) { - if ((timer_read() - timeout_timer) > I2C_TIMEOUT) { - return 2; // should make these codes standard - } + uint16_t timeout_timer = timer_read(); + while( !(TWCR & (1<<TWINT)) ) { + if (timeout && (timer_read() - timeout_timer) > I2C_TIMEOUT) { + return I2C_STATUS_TIMEOUT; } - #else - // wait for end of transmission - while( !(TWCR & (1<<TWINT)) ); - #endif + } if( (TW_STATUS & 0xF8) != TW_MT_DATA_ACK ){ return 1; } return 0; } -uint8_t i2c_read_ack(void) +i2c_status_t i2c_read_ack(uint8_t timeout) { // start TWI module and acknowledge data after reception TWCR = (1<<TWINT) | (1<<TWEN) | (1<<TWEA); - #ifdef I2C_TIMEOUT - uint16_t timeout_timer = timer_read(); - while( !(TWCR & (1<<TWINT)) ) { - if ((timer_read() - timeout_timer) > I2C_TIMEOUT) { - return 2; // should make these codes standard - } + uint16_t timeout_timer = timer_read(); + while( !(TWCR & (1<<TWINT)) ) { + if (timeout && (timer_read() - timeout_timer) > I2C_TIMEOUT) { + return I2C_STATUS_TIMEOUT; } - #else - // wait for end of transmission - while( !(TWCR & (1<<TWINT)) ); - #endif + } // return received data from TWDR return TWDR; } -uint8_t i2c_read_nack(void) +i2c_status_t i2c_read_nack(uint8_t timeout) { // start receiving without acknowledging reception TWCR = (1<<TWINT) | (1<<TWEN); - #ifdef I2C_TIMEOUT - uint16_t timeout_timer = timer_read(); - while( !(TWCR & (1<<TWINT)) ) { - if ((timer_read() - timeout_timer) > I2C_TIMEOUT) { - return 2; // should make these codes standard - } + uint16_t timeout_timer = timer_read(); + while( !(TWCR & (1<<TWINT)) ) { + if (timeout && (timer_read() - timeout_timer) > I2C_TIMEOUT) { + return I2C_STATUS_TIMEOUT; } - #else - // wait for end of transmission - while( !(TWCR & (1<<TWINT)) ); - #endif + } // return received data from TWDR return TWDR; } -uint8_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) { if (i2c_start(address | I2C_WRITE)) return 1; @@ -197,22 +172,17 @@ uint8_t i2c_readReg(uint8_t devaddr, uint8_t regaddr, uint8_t* data, uint16_t le return 0; } -uint8_t i2c_stop(void) +i2c_status_t i2c_stop(uint8_t timeout) { // transmit STOP condition TWCR = (1<<TWINT) | (1<<TWEN) | (1<<TWSTO); - #ifdef I2C_TIMEOUT - uint16_t timeout_timer = timer_read(); - while(TWCR & (1<<TWSTO)) { - if ((timer_read() - timeout_timer) > I2C_TIMEOUT) { - return 2; // should make these codes standard - } + uint16_t timeout_timer = timer_read(); + while(TWCR & (1<<TWSTO)) { + if (timeout && (timer_read() - timeout_timer) > I2C_TIMEOUT) { + return I2C_STATUS_TIMEOUT; } - #else - // wait for end of transmission - while(TWCR & (1<<TWSTO)); - #endif + } return 0; } diff --git a/drivers/avr/i2c_master.h b/drivers/avr/i2c_master.h index 8686807146..3c7731e8dc 100755 --- a/drivers/avr/i2c_master.h +++ b/drivers/avr/i2c_master.h @@ -8,15 +8,20 @@ #define I2C_READ 0x01 #define I2C_WRITE 0x00 +typedef i2c_status_t int16_t +#define I2C_STATUS_TIMEOUT (-1) + +#define I2C_NO_TIMEOUT 0 + void i2c_init(void); -uint8_t i2c_start(uint8_t address); -uint8_t i2c_write(uint8_t data); -uint8_t i2c_read_ack(void); -uint8_t i2c_read_nack(void); +i2c_status_t i2c_start(uint8_t address, uint8_t timeout); +i2c_status_t i2c_write(uint8_t data, uint8_t timeout); +i2c_status_t i2c_read_ack(uint8_t timeout); +i2c_status_t i2c_read_nack(uint8_t timeout); uint8_t i2c_transmit(uint8_t address, uint8_t* data, uint16_t length); uint8_t i2c_receive(uint8_t address, uint8_t* data, uint16_t length); uint8_t i2c_writeReg(uint8_t devaddr, uint8_t regaddr, uint8_t* data, uint16_t length); uint8_t i2c_readReg(uint8_t devaddr, uint8_t regaddr, uint8_t* data, uint16_t length); -uint8_t i2c_stop(void); +i2c_status_t i2c_stop(uint8_t timeout); #endif // I2C_MASTER_H |