static int
i2c_interrupt(int irq, FAR void *context)
{
uint16_t sr1 = rSR1;
if (sr1 & (I2C_SR1_STOPF | I2C_SR1_AF | I2C_SR1_ADDR)) {
if (sr1 & I2C_SR1_STOPF) {
/* write to CR1 to clear STOPF */
(void)rSR1; /* as recommended, re-read SR1 */
rCR1 |= I2C_CR1_PE;
}
/* DMA never stops, so we should do that now */
switch (direction) {
case DIR_TX:
i2c_tx_complete();
break;
case DIR_RX:
i2c_rx_complete();
break;
default:
/* not currently transferring - must be a new txn */
break;
}
direction = DIR_NONE;
}
if (sr1 & I2C_SR1_ADDR) {
/* clear ADDR to ack our selection and get direction */
(void)rSR1; /* as recommended, re-read SR1 */
uint16_t sr2 = rSR2;
if (sr2 & I2C_SR2_TRA) {
/* we are the transmitter */
direction = DIR_TX;
} else {
/* we are the receiver */
direction = DIR_RX;
}
}
/* clear any errors that might need it (this handles AF as well */
if (sr1 & I2C_SR1_ERRORMASK) {
rSR1 = 0;
}
return 0;
}
/*
* Receives a data byte from the slave-transmitter and returns it
* @param delay_us Delay in microseconds following the read
* @return Byte read from the line
*/
uint8_t i2c_rx_byte(int delay_us) {
uint8_t ret = MCF_I2C0_I2DR; // Read, which generates SCL for the slave to transmit
// Wait for transfer to finish
while(!i2c_tx_complete()) {
}
MCF_I2C0_I2SR &= ~(MCF_I2C_I2SR_IIF); // Clear interrupt request flag
// Delay for delay_us following the transfer
dtim0_delay_us(delay_us);
return ret;
}
/*
* Send a single byte of data to the slave
*
* @param data Byte to send
* @param delay_us Microseconds to delay after the send
*/
void i2c_tx_byte(uint8_t data, int delay_us) {
//asm_set_ipl(7); // Mask all interrupt levels !!! necessary?
// Write data
MCF_I2C0_I2DR = data;
// Wait for data to finish transmitting
while(!i2c_tx_complete()) {
}
MCF_I2C0_I2SR &= ~(MCF_I2C_I2SR_IIF); // Clear interrupt request flag
//asm_set_ipl(0); // Unmask all interrupt levels !!! necessary?
// Delay for delay_us following the transfer
dtim0_delay_us(delay_us);
}
