diff options
Diffstat (limited to 'drivers/avr')
-rwxr-xr-x | drivers/avr/i2c_master.c | 160 | ||||
-rwxr-xr-x | drivers/avr/i2c_master.h | 2 | ||||
-rwxr-xr-x | drivers/avr/i2c_slave.c | 2 |
3 files changed, 69 insertions, 95 deletions
diff --git a/drivers/avr/i2c_master.c b/drivers/avr/i2c_master.c index 19bae33e9f..0db949db4a 100755 --- a/drivers/avr/i2c_master.c +++ b/drivers/avr/i2c_master.c @@ -7,43 +7,44 @@ #include "i2c_master.h" #include "timer.h" +#include "wait.h" #ifndef F_SCL -#define F_SCL 400000UL // SCL frequency +# define F_SCL 400000UL // SCL frequency #endif #define Prescaler 1 -#define TWBR_val ((((F_CPU / F_SCL) / Prescaler) - 16 ) / 2) +#define TWBR_val ((((F_CPU / F_SCL) / Prescaler) - 16) / 2) -void i2c_init(void) -{ - TWSR = 0; /* no prescaler */ +void i2c_init(void) { + TWSR = 0; /* no prescaler */ TWBR = (uint8_t)TWBR_val; } -i2c_status_t i2c_start(uint8_t address, uint16_t timeout) -{ +i2c_status_t i2c_start(uint8_t address, uint16_t timeout) { // reset TWI control register TWCR = 0; // transmit START condition - TWCR = (1<<TWINT) | (1<<TWSTA) | (1<<TWEN); + TWCR = (1 << TWINT) | (1 << TWSTA) | (1 << TWEN); uint16_t timeout_timer = timer_read(); - while( !(TWCR & (1<<TWINT)) ) { + while (!(TWCR & (1 << TWINT))) { if ((timeout != I2C_TIMEOUT_INFINITE) && ((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 I2C_STATUS_ERROR; } + if (((TW_STATUS & 0xF8) != TW_START) && ((TW_STATUS & 0xF8) != TW_REP_START)) { + return I2C_STATUS_ERROR; + } // load slave address into data register TWDR = address; // start transmission of address - TWCR = (1<<TWINT) | (1<<TWEN); + TWCR = (1 << TWINT) | (1 << TWEN); timeout_timer = timer_read(); - while( !(TWCR & (1<<TWINT)) ) { + while (!(TWCR & (1 << TWINT))) { if ((timeout != I2C_TIMEOUT_INFINITE) && ((timer_read() - timeout_timer) >= timeout)) { return I2C_STATUS_TIMEOUT; } @@ -51,38 +52,39 @@ i2c_status_t i2c_start(uint8_t address, uint16_t 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 I2C_STATUS_ERROR; + if ((twst != TW_MT_SLA_ACK) && (twst != TW_MR_SLA_ACK)) { + return I2C_STATUS_ERROR; + } return I2C_STATUS_SUCCESS; } -i2c_status_t i2c_write(uint8_t data, uint16_t timeout) -{ +i2c_status_t i2c_write(uint8_t data, uint16_t timeout) { // load data into data register TWDR = data; // start transmission of data - TWCR = (1<<TWINT) | (1<<TWEN); + TWCR = (1 << TWINT) | (1 << TWEN); uint16_t timeout_timer = timer_read(); - while( !(TWCR & (1<<TWINT)) ) { + while (!(TWCR & (1 << TWINT))) { if ((timeout != I2C_TIMEOUT_INFINITE) && ((timer_read() - timeout_timer) >= timeout)) { return I2C_STATUS_TIMEOUT; } } - if( (TW_STATUS & 0xF8) != TW_MT_DATA_ACK ){ return I2C_STATUS_ERROR; } + if ((TW_STATUS & 0xF8) != TW_MT_DATA_ACK) { + return I2C_STATUS_ERROR; + } return I2C_STATUS_SUCCESS; } -int16_t i2c_read_ack(uint16_t timeout) -{ - +int16_t i2c_read_ack(uint16_t timeout) { // start TWI module and acknowledge data after reception - TWCR = (1<<TWINT) | (1<<TWEN) | (1<<TWEA); + TWCR = (1 << TWINT) | (1 << TWEN) | (1 << TWEA); uint16_t timeout_timer = timer_read(); - while( !(TWCR & (1<<TWINT)) ) { + while (!(TWCR & (1 << TWINT))) { if ((timeout != I2C_TIMEOUT_INFINITE) && ((timer_read() - timeout_timer) >= timeout)) { return I2C_STATUS_TIMEOUT; } @@ -92,14 +94,12 @@ int16_t i2c_read_ack(uint16_t timeout) return TWDR; } -int16_t i2c_read_nack(uint16_t timeout) -{ - +int16_t i2c_read_nack(uint16_t timeout) { // start receiving without acknowledging reception - TWCR = (1<<TWINT) | (1<<TWEN); + TWCR = (1 << TWINT) | (1 << TWEN); uint16_t timeout_timer = timer_read(); - while( !(TWCR & (1<<TWINT)) ) { + while (!(TWCR & (1 << TWINT))) { if ((timeout != I2C_TIMEOUT_INFINITE) && ((timer_read() - timeout_timer) >= timeout)) { return I2C_STATUS_TIMEOUT; } @@ -109,115 +109,89 @@ int16_t i2c_read_nack(uint16_t timeout) return TWDR; } -i2c_status_t i2c_transmit(uint8_t address, uint8_t* data, uint16_t length, uint16_t timeout) -{ +i2c_status_t i2c_transmit(uint8_t address, uint8_t* data, uint16_t length, uint16_t timeout) { i2c_status_t status = i2c_start(address | I2C_WRITE, timeout); - if (status) return status; - for (uint16_t i = 0; i < length; i++) { + for (uint16_t i = 0; i < length && status >= 0; i++) { status = i2c_write(data[i], timeout); - if (status) return status; } - status = i2c_stop(timeout); - if (status) return status; + i2c_stop(); - return I2C_STATUS_SUCCESS; + return status; } -i2c_status_t i2c_receive(uint8_t address, uint8_t* data, uint16_t length, uint16_t timeout) -{ +i2c_status_t i2c_receive(uint8_t address, uint8_t* data, uint16_t length, uint16_t timeout) { i2c_status_t status = i2c_start(address | I2C_READ, timeout); - if (status) return status; - for (uint16_t i = 0; i < (length-1); i++) { + for (uint16_t i = 0; i < (length - 1) && status >= 0; i++) { status = i2c_read_ack(timeout); if (status >= 0) { data[i] = status; - } else { - return status; } } - status = i2c_read_nack(timeout); - if (status >= 0 ) { - data[(length-1)] = status; - } else { - return status; + if (status >= 0) { + status = i2c_read_nack(timeout); + if (status >= 0) { + data[(length - 1)] = status; + } } - status = i2c_stop(timeout); - if (status) return status; + i2c_stop(); - return I2C_STATUS_SUCCESS; + return (status < 0) ? status : I2C_STATUS_SUCCESS; } -i2c_status_t i2c_writeReg(uint8_t devaddr, uint8_t regaddr, uint8_t* data, uint16_t length, uint16_t timeout) -{ +i2c_status_t i2c_writeReg(uint8_t devaddr, uint8_t regaddr, uint8_t* data, uint16_t length, uint16_t timeout) { i2c_status_t status = i2c_start(devaddr | 0x00, timeout); - if (status) return status; - - status = i2c_write(regaddr, timeout); - if (status) return status; + if (status >= 0) { + status = i2c_write(regaddr, timeout); - for (uint16_t i = 0; i < length; i++) { - status = i2c_write(data[i], timeout); - if (status) return status; + for (uint16_t i = 0; i < length && status >= 0; i++) { + status = i2c_write(data[i], timeout); + } } - status = i2c_stop(timeout); - if (status) return status; + i2c_stop(); - return I2C_STATUS_SUCCESS; + return status; } -i2c_status_t i2c_readReg(uint8_t devaddr, uint8_t regaddr, uint8_t* data, uint16_t length, uint16_t timeout) -{ +i2c_status_t i2c_readReg(uint8_t devaddr, uint8_t regaddr, uint8_t* data, uint16_t length, uint16_t timeout) { i2c_status_t status = i2c_start(devaddr, timeout); - if (status) return status; + if (status < 0) { + goto error; + } status = i2c_write(regaddr, timeout); - if (status) return status; - - status = i2c_stop(timeout); - if (status) return status; + if (status < 0) { + goto error; + } status = i2c_start(devaddr | 0x01, timeout); - if (status) return status; - for (uint16_t i = 0; i < (length-1); i++) { + for (uint16_t i = 0; i < (length - 1) && status >= 0; i++) { status = i2c_read_ack(timeout); if (status >= 0) { data[i] = status; - } else { - return status; } } - status = i2c_read_nack(timeout); - if (status >= 0 ) { - data[(length-1)] = status; - } else { - return status; + if (status >= 0) { + status = i2c_read_nack(timeout); + if (status >= 0) { + data[(length - 1)] = status; + } } - status = i2c_stop(timeout); - if (status) return status; +error: + i2c_stop(); - return I2C_STATUS_SUCCESS; + return (status < 0) ? status : I2C_STATUS_SUCCESS; } -i2c_status_t i2c_stop(uint16_t timeout) -{ +void i2c_stop(void) { // transmit STOP condition - TWCR = (1<<TWINT) | (1<<TWEN) | (1<<TWSTO); - - uint16_t timeout_timer = timer_read(); - while(TWCR & (1<<TWSTO)) { - if ((timeout != I2C_TIMEOUT_INFINITE) && ((timer_read() - timeout_timer) >= timeout)) { - return I2C_STATUS_TIMEOUT; - } - } - - return I2C_STATUS_SUCCESS; + TWCR = (1 << TWINT) | (1 << TWEN) | (1 << TWSTO); } diff --git a/drivers/avr/i2c_master.h b/drivers/avr/i2c_master.h index 89c64599c5..81a7fb5e32 100755 --- a/drivers/avr/i2c_master.h +++ b/drivers/avr/i2c_master.h @@ -26,6 +26,6 @@ i2c_status_t i2c_transmit(uint8_t address, uint8_t* data, uint16_t length, uint1 i2c_status_t i2c_receive(uint8_t address, uint8_t* data, uint16_t length, uint16_t timeout); i2c_status_t i2c_writeReg(uint8_t devaddr, uint8_t regaddr, uint8_t* data, uint16_t length, uint16_t timeout); i2c_status_t i2c_readReg(uint8_t devaddr, uint8_t regaddr, uint8_t* data, uint16_t length, uint16_t timeout); -i2c_status_t i2c_stop(uint16_t timeout); +void i2c_stop(void); #endif // I2C_MASTER_H
\ No newline at end of file diff --git a/drivers/avr/i2c_slave.c b/drivers/avr/i2c_slave.c index 18a29a45a5..dbb9fb0df3 100755 --- a/drivers/avr/i2c_slave.c +++ b/drivers/avr/i2c_slave.c @@ -16,7 +16,7 @@ static volatile bool slave_has_register_set = false; void i2c_slave_init(uint8_t address){ // load address into TWI address register - TWAR = (address << 1); + TWAR = address; // set the TWCR to enable address matching and enable TWI, clear TWINT, enable TWI interrupt TWCR = (1 << TWIE) | (1 << TWEA) | (1 << TWINT) | (1 << TWEN); } |