/**
* @brief Transmits data via the I2C bus as master.
*
* @param[in] i2cp pointer to the @p I2CDriver object
* @param[in] addr slave device address
* @param[in] txbuf pointer to the transmit buffer
* @param[in] txbytes number of bytes to be transmitted
* @param[out] rxbuf pointer to the receive buffer
* @param[in] rxbytes number of bytes to be received
* @param[in] timeout the number of ticks before the operation timeouts,
* the following special values are allowed:
* - @a TIME_INFINITE no timeout.
* .
* @return The operation status.
* @retval RDY_OK if the function succeeded.
* @retval RDY_RESET if one or more I2C errors occurred, the errors can
* be retrieved using @p i2cGetErrors().
* @retval RDY_TIMEOUT if a timeout occurred before operation end. <b>After a
* timeout the driver must be stopped and restarted
* because the bus is in an uncertain state</b>.
*
* @notapi
*/
msg_t i2c_lld_master_transmit_timeout(I2CDriver *i2cp, i2caddr_t addr,
const uint8_t *txbuf, size_t txbytes,
uint8_t *rxbuf, size_t rxbytes,
systime_t timeout)
{
I2C_TypeDef *dp = i2cp->i2c;
systime_t start, end;
i2cp->rxbuf = rxbuf;
i2cp->rxbytes = rxbytes;
i2cp->txbuf = txbuf;
i2cp->txbytes = txbytes;
/* Resetting error flags for this transfer.*/
i2cp->errors = I2C_NO_ERROR;
/* Releases the lock from high level driver.*/
osalSysUnlock();
/* Calculating the time window for the timeout on the busy bus condition.*/
start = osalOsGetSystemTimeX();
end = start + OSAL_MS2ST(TIVA_I2C_BUSY_TIMEOUT);
/* Waits until BUSY flag is reset or, alternatively, for a timeout
condition.*/
while (true) {
osalSysLock();
/* If the bus is not busy then the operation can continue, note, the
loop is exited in the locked state.*/
if ((dp->MCS & TIVA_MCS_BUSY) == 0)
break;
/* If the system time went outside the allowed window then a timeout
condition is returned.*/
if (!osalOsIsTimeWithinX(osalOsGetSystemTimeX(), start, end))
return MSG_TIMEOUT;
osalSysUnlock();
}
/* Initializes driver fields, LSB = 0 -> write.*/
i2cp->addr = addr << 1 | 0;
/* set slave address */
dp->MSA = i2cp->addr;
/* enable interrupts */
dp->MIMR = TIVA_MIMR_IM;
/* put data in register */
dp->MDR = *(i2cp->txbuf);
/* check if 1 or more bytes */
if (i2cp->txbytes == 1) {
if (i2cp->rxbytes == 1) {
// one byte read
i2cp->intstate = STATE_READ_ONE;
}
else {
// multiple byte read
i2cp->intstate = STATE_READ_FIRST;
}
// single byte send
dp->MCS = TIVA_I2C_SIGNLE_SEND;
}
else {
if (i2cp->txbytes == 2) {
// 2 bytes
i2cp->intstate = STATE_WRITE_FINAL;
}
else {
// more then 2 bytes
i2cp->intstate = STATE_WRITE_NEXT;
}
// multiple bytes start send
dp->MCS = TIVA_I2C_BURST_SEND_START;
}
i2cp->txbuf++;
i2cp->txbytes--;
/* Waits for the operation completion or a timeout.*/
return osalThreadSuspendTimeoutS(&i2cp->thread, timeout);
}
/**
* @brief Transmits data via the I2C bus as master.
* @details Number of receiving bytes must be 0 or more than 1 on STM32F1x.
* This is hardware restriction.
*
* @param[in] i2cp pointer to the @p I2CDriver object
* @param[in] addr slave device address
* @param[in] txbuf pointer to the transmit buffer
* @param[in] txbytes number of bytes to be transmitted
* @param[out] rxbuf pointer to the receive buffer
* @param[in] rxbytes number of bytes to be received
* @param[in] timeout the number of ticks before the operation timeouts,
* the following special values are allowed:
* - @a TIME_INFINITE no timeout.
* .
* @return The operation status.
* @retval MSG_OK if the function succeeded.
* @retval MSG_RESET if one or more I2C errors occurred, the errors can
* be retrieved using @p i2cGetErrors().
* @retval MSG_TIMEOUT if a timeout occurred before operation end. <b>After a
* timeout the driver must be stopped and restarted
* because the bus is in an uncertain state</b>.
*
* @notapi
*/
msg_t i2c_lld_master_transmit_timeout(I2CDriver *i2cp, i2caddr_t addr,
const uint8_t *txbuf, size_t txbytes,
uint8_t *rxbuf, size_t rxbytes,
systime_t timeout) {
msg_t msg;
I2C_TypeDef *dp = i2cp->i2c;
systime_t start, end;
/* Resetting error flags for this transfer.*/
i2cp->errors = I2C_NO_ERROR;
/* Releases the lock from high level driver.*/
osalSysUnlock();
#if STM32_I2C_USE_DMA == TRUE
/* TX DMA setup.*/
dmaStreamSetMode(i2cp->dmatx, i2cp->txdmamode);
dmaStreamSetMemory0(i2cp->dmatx, txbuf);
dmaStreamSetTransactionSize(i2cp->dmatx, txbytes);
/* RX DMA setup, note, rxbytes can be zero but we write the value anyway.*/
dmaStreamSetMode(i2cp->dmarx, i2cp->rxdmamode);
dmaStreamSetMemory0(i2cp->dmarx, rxbuf);
dmaStreamSetTransactionSize(i2cp->dmarx, rxbytes);
#else
i2cp->txptr = txbuf;
i2cp->txbytes = txbytes;
i2cp->rxptr = rxbuf;
i2cp->rxbytes = rxbytes;
#endif
/* Calculating the time window for the timeout on the busy bus condition.*/
start = osalOsGetSystemTimeX();
end = start + OSAL_MS2ST(STM32_I2C_BUSY_TIMEOUT);
/* Waits until BUSY flag is reset or, alternatively, for a timeout
condition.*/
while (true) {
osalSysLock();
/* If the bus is not busy then the operation can continue, note, the
loop is exited in the locked state.*/
if ((dp->ISR & I2C_ISR_BUSY) == 0)
break;
/* If the system time went outside the allowed window then a timeout
condition is returned.*/
if (!osalOsIsTimeWithinX(osalOsGetSystemTimeX(), start, end)) {
return MSG_TIMEOUT;
}
osalSysUnlock();
}
/* Setting up the slave address.*/
i2c_lld_set_address(i2cp, addr);
/* Preparing the transfer.*/
i2c_lld_setup_tx_transfer(i2cp);
#if STM32_I2C_USE_DMA == TRUE
/* Enabling TX DMA.*/
dmaStreamEnable(i2cp->dmatx);
/* Transfer complete interrupt enabled.*/
dp->CR1 |= I2C_CR1_TCIE;
#else
/* Transfer complete and TX interrupts enabled.*/
dp->CR1 |= I2C_CR1_TCIE | I2C_CR1_TXIE;
#endif
/* Starts the operation.*/
dp->CR2 |= I2C_CR2_START;
/* Waits for the operation completion or a timeout.*/
msg = osalThreadSuspendTimeoutS(&i2cp->thread, timeout);
/* In case of a software timeout a STOP is sent as an extreme attempt
to release the bus.*/
if (msg == MSG_TIMEOUT) {
dp->CR2 |= I2C_CR2_STOP;
}
return msg;
}