int i2c_write_regs(i2c_t dev, uint8_t address, uint8_t reg, const void *data, int length)
{
I2C_TypeDef *i2c;
switch (dev) {
#if I2C_0_EN
case I2C_0:
i2c = I2C_0_DEV;
break;
#endif
#if I2C_1_EN
case I2C_1:
i2c = I2C_1_DEV;
break;
#endif
default:
return -1;
}
/* start transmission and send slave address */
_start(i2c, address, I2C_FLAG_WRITE);
_clear_addr(i2c);
/* send register address and wait for complete transfer to be finished*/
_write(i2c, ®, 1);
/* write data to register */
_write(i2c, data, length);
/* finish transfer */
_stop(i2c);
/* return number of bytes send */
return length;
}
int i2c_read_regs(i2c_t dev, uint8_t address, uint8_t reg, void *data, int length)
{
I2C_TypeDef *i2c;
switch (dev) {
#if I2C_0_EN
case I2C_0:
i2c = I2C_0_DEV;
break;
#endif
#if I2C_1_EN
case I2C_1:
i2c = I2C_1_DEV;
break;
#endif
default:
return -1;
}
/* send start condition and slave address */
DEBUG("Send slave address and clear ADDR flag\n");
_start(i2c, address, I2C_FLAG_WRITE);
_clear_addr(i2c);
DEBUG("Write reg into DR\n");
i2c->DR = reg;
_stop(i2c);
DEBUG("Now start a read transaction\n");
return i2c_read_bytes(dev, address, data, length);
}
int i2c_write_bytes(i2c_t dev, uint8_t address, const void *data, int length)
{
I2C_TypeDef *i2c;
switch (dev) {
#if I2C_0_EN
case I2C_0:
i2c = I2C_0_DEV;
break;
#endif
#if I2C_1_EN
case I2C_1:
i2c = I2C_1_DEV;
break;
#endif
default:
return -1;
}
/* start transmission and send slave address */
DEBUG("sending start sequence\n");
_start(i2c, address, I2C_FLAG_WRITE);
_clear_addr(i2c);
/* send out data bytes */
_write(i2c, data, length);
/* end transmission */
DEBUG("Ending transmission\n");
_stop(i2c);
DEBUG("STOP condition was send out\n");
return length;
}
int i2c_read_regs(i2c_t dev, uint8_t address, uint8_t reg, char *data, int length)
{
if ((unsigned int)dev >= I2C_NUMOF) {
return -1;
}
I2C_TypeDef *i2c = i2c_config[dev].dev;
/* send start condition and slave address */
DEBUG("Send slave address and clear ADDR flag\n");
_start(i2c, address, I2C_FLAG_WRITE);
_clear_addr(i2c);
DEBUG("Write reg into DR\n");
i2c->DR = reg;
_stop(i2c);
DEBUG("Now start a read transaction\n");
return i2c_read_bytes(dev, address, data, length);
}
int i2c_write_regs(i2c_t dev, uint8_t address, uint8_t reg, char *data, int length)
{
if ((unsigned int)dev >= I2C_NUMOF) {
return -1;
}
I2C_TypeDef *i2c = i2c_config[dev].dev;
/* start transmission and send slave address */
_start(i2c, address, I2C_FLAG_WRITE);
_clear_addr(i2c);
/* send register address and wait for complete transfer to be finished*/
_write(i2c, (char *)(®), 1);
/* write data to register */
_write(i2c, data, length);
/* finish transfer */
_stop(i2c);
/* return number of bytes send */
return length;
}
int i2c_write_bytes(i2c_t dev, uint8_t address, char *data, int length)
{
if ((unsigned int)dev >= I2C_NUMOF) {
return -1;
}
I2C_TypeDef *i2c = i2c_config[dev].dev;
/* start transmission and send slave address */
DEBUG("sending start sequence\n");
_start(i2c, address, I2C_FLAG_WRITE);
_clear_addr(i2c);
/* send out data bytes */
_write(i2c, data, length);
/* end transmission */
DEBUG("Ending transmission\n");
_stop(i2c);
DEBUG("STOP condition was send out\n");
return length;
}
int i2c_read_bytes(i2c_t dev, uint8_t address, void *data, int length)
{
unsigned int state;
int i = 0;
I2C_TypeDef *i2c;
uint8_t *my_data = data;
switch (dev) {
#if I2C_0_EN
case I2C_0:
i2c = I2C_0_DEV;
break;
#endif
#if I2C_1_EN
case I2C_1:
i2c = I2C_1_DEV;
break;
#endif
default:
return -1;
}
switch (length) {
case 1:
DEBUG("Send Slave address and wait for ADDR == 1\n");
_start(i2c, address, I2C_FLAG_READ);
DEBUG("Set ACK = 0\n");
i2c->CR1 &= ~(I2C_CR1_ACK);
DEBUG("Clear ADDR and set STOP = 1\n");
state = irq_disable();
_clear_addr(i2c);
i2c->CR1 |= (I2C_CR1_STOP);
irq_restore(state);
DEBUG("Wait for RXNE == 1\n");
while (!(i2c->SR1 & I2C_SR1_RXNE)) {}
DEBUG("Read received data\n");
*my_data = i2c->DR;
/* wait until STOP is cleared by hardware */
while (i2c->CR1 & I2C_CR1_STOP) {}
/* reset ACK to be able to receive new data */
i2c->CR1 |= (I2C_CR1_ACK);
break;
case 2:
DEBUG("Send Slave address and wait for ADDR == 1\n");
_start(i2c, address, I2C_FLAG_READ);
DEBUG("Set POS bit\n");
i2c->CR1 |= (I2C_CR1_POS | I2C_CR1_ACK);
DEBUG("Crit block: Clear ADDR bit and clear ACK flag\n");
state = irq_disable();
_clear_addr(i2c);
i2c->CR1 &= ~(I2C_CR1_ACK);
irq_restore(state);
DEBUG("Wait for transfer to be completed\n");
while (!(i2c->SR1 & I2C_SR1_BTF)) {}
DEBUG("Crit block: set STOP and read first byte\n");
state = irq_disable();
i2c->CR1 |= (I2C_CR1_STOP);
my_data[0] = i2c->DR;
irq_restore(state);
DEBUG("read second byte\n");
my_data[1] = i2c->DR;
DEBUG("wait for STOP bit to be cleared again\n");
while (i2c->CR1 & I2C_CR1_STOP) {}
DEBUG("reset POS = 0 and ACK = 1\n");
i2c->CR1 &= ~(I2C_CR1_POS);
i2c->CR1 |= (I2C_CR1_ACK);
break;
default:
DEBUG("Send Slave address and wait for ADDR == 1\n");
_start(i2c, address, I2C_FLAG_READ);
_clear_addr(i2c);
while (i < (length - 3)) {
DEBUG("Wait until byte was received\n");
while (!(i2c->SR1 & I2C_SR1_RXNE)) {}
DEBUG("Copy byte from DR\n");
my_data[i++] = i2c->DR;
}
DEBUG("Reading the last 3 bytes, waiting for BTF flag\n");
while (!(i2c->SR1 & I2C_SR1_BTF)) {}
DEBUG("Disable ACK\n");
i2c->CR1 &= ~(I2C_CR1_ACK);
DEBUG("Crit block: set STOP and read N-2 byte\n");
state = irq_disable();
my_data[i++] = i2c->DR;
i2c->CR1 |= (I2C_CR1_STOP);
irq_restore(state);
DEBUG("Read N-1 byte\n");
my_data[i++] = i2c->DR;
while (!(i2c->SR1 & I2C_SR1_RXNE)) {}
DEBUG("Read last byte\n");
my_data[i++] = i2c->DR;
DEBUG("wait for STOP bit to be cleared again\n");
while (i2c->CR1 & I2C_CR1_STOP) {}
DEBUG("reset POS = 0 and ACK = 1\n");
i2c->CR1 &= ~(I2C_CR1_POS);
i2c->CR1 |= (I2C_CR1_ACK);
}
return length;
}
int i2c_read_bytes(i2c_t dev, uint8_t address, char *data, int length)
{
unsigned int state;
int i = 0;
if ((unsigned int)dev >= I2C_NUMOF) {
return -1;
}
I2C_TypeDef *i2c = i2c_config[dev].dev;
switch (length) {
case 1:
DEBUG("Send Slave address and wait for ADDR == 1\n");
_start(i2c, address, I2C_FLAG_READ);
DEBUG("Set ACK = 0\n");
i2c->CR1 &= ~(I2C_CR1_ACK);
DEBUG("Clear ADDR and set STOP = 1\n");
state = disableIRQ();
_clear_addr(i2c);
i2c->CR1 |= (I2C_CR1_STOP);
restoreIRQ(state);
DEBUG("Wait for RXNE == 1\n");
while (!(i2c->SR1 & I2C_SR1_RXNE));
DEBUG("Read received data\n");
*data = (char)i2c->DR;
/* wait until STOP is cleared by hardware */
while (i2c->CR1 & I2C_CR1_STOP);
/* reset ACK to be able to receive new data */
i2c->CR1 |= (I2C_CR1_ACK);
break;
case 2:
DEBUG("Send Slave address and wait for ADDR == 1\n");
_start(i2c, address, I2C_FLAG_READ);
DEBUG("Set POS bit\n");
i2c->CR1 |= (I2C_CR1_POS | I2C_CR1_ACK);
DEBUG("Crit block: Clear ADDR bit and clear ACK flag\n");
state = disableIRQ();
_clear_addr(i2c);
i2c->CR1 &= ~(I2C_CR1_ACK);
restoreIRQ(state);
DEBUG("Wait for transfer to be completed\n");
while (!(i2c->SR1 & I2C_SR1_BTF));
DEBUG("Crit block: set STOP and read first byte\n");
state = disableIRQ();
i2c->CR1 |= (I2C_CR1_STOP);
data[0] = (char)i2c->DR;
restoreIRQ(state);
DEBUG("read second byte\n");
data[1] = (char)i2c->DR;
DEBUG("wait for STOP bit to be cleared again\n");
while (i2c->CR1 & I2C_CR1_STOP);
DEBUG("reset POS = 0 and ACK = 1\n");
i2c->CR1 &= ~(I2C_CR1_POS);
i2c->CR1 |= (I2C_CR1_ACK);
break;
default:
DEBUG("Send Slave address and wait for ADDR == 1\n");
_start(i2c, address, I2C_FLAG_READ);
_clear_addr(i2c);
while (i < (length - 3)) {
DEBUG("Wait until byte was received\n");
while (!(i2c->SR1 & I2C_SR1_RXNE));
DEBUG("Copy byte from DR\n");
data[i++] = (char)i2c->DR;
}
DEBUG("Reading the last 3 bytes, waiting for BTF flag\n");
while (!(i2c->SR1 & I2C_SR1_BTF));
DEBUG("Disable ACK\n");
i2c->CR1 &= ~(I2C_CR1_ACK);
DEBUG("Crit block: set STOP and read N-2 byte\n");
state = disableIRQ();
data[i++] = (char)i2c->DR;
i2c->CR1 |= (I2C_CR1_STOP);
restoreIRQ(state);
DEBUG("Read N-1 byte\n");
data[i++] = (char)i2c->DR;
while (!(i2c->SR1 & I2C_SR1_RXNE));
DEBUG("Read last byte\n");
data[i++] = (char)i2c->DR;
DEBUG("wait for STOP bit to be cleared again\n");
while (i2c->CR1 & I2C_CR1_STOP);
DEBUG("reset POS = 0 and ACK = 1\n");
i2c->CR1 &= ~(I2C_CR1_POS);
i2c->CR1 |= (I2C_CR1_ACK);
}
return length;
}
