/**
* @brief Common IRQ handler.
*
* @param[in] spip pointer to the @p SPIDriver object
*/
static void serve_interrupt(SPIDriver *spip) {
SSP *ssp = spip->spd_ssp;
if ((ssp->SSP_MIS & MIS_ROR) != 0) {
/* The overflow condition should never happen because priority is given
to receive but a hook macro is provided anyway...*/
LPC214x_SPI_SSP_ERROR_HOOK();
}
ssp->SSP_ICR = ICR_RT | ICR_ROR;
while ((ssp->SSP_SR & SR_RNE) != 0) {
if (spip->spd_rxptr != NULL) {
if ((ssp->SSP_CR0 & CR0_DSSMASK) > CR0_DSS8BIT)
*(uint16_t *)spip->spd_rxptr++ = ssp->SSP_DR;
else
*(uint8_t *)spip->spd_rxptr++ = ssp->SSP_DR;
}
else
(void)ssp->SSP_DR;
if (--spip->spd_rxcnt == 0) {
chDbgAssert(spip->spd_txcnt == 0,
"spi_serve_interrupt(), #1", "counter out of synch");
/* Stops the IRQ sources.*/
ssp->SSP_IMSC = 0;
/* Portable SPI ISR code defined in the high level driver, note, it is
a macro.*/
_spi_isr_code(spip);
return;
}
}
ssp_fifo_preload(spip);
if (spip->spd_txcnt == 0)
ssp->SSP_IMSC = IMSC_ROR | IMSC_RT | IMSC_RX;
}
/**
* @brief Receives data from the SPI bus.
* @details This asynchronous function starts a receive operation.
* @post At the end of the operation the configured callback is invoked.
* @note The buffers are organized as uint8_t arrays for data sizes below or
* equal to 8 bits else it is organized as uint16_t arrays.
*
* @param[in] spip pointer to the @p SPIDriver object
* @param[in] n number of words to receive
* @param[out] rxbuf the pointer to the receive buffer
*
* @notapi
*/
void spi_lld_receive(SPIDriver *spip, size_t n, void *rxbuf) {
spip->rxptr = rxbuf;
spip->txptr = NULL;
spip->rxcnt = spip->txcnt = n;
ssp_fifo_preload(spip);
spip->ssp->IMSC = IMSC_ROR | IMSC_RT | IMSC_TX | IMSC_RX;
}
/**
* @brief Sends data over the SPI bus.
* @details This asynchronous function starts a transmit operation.
* @post At the end of the operation the configured callback is invoked.
* @note The buffers are organized as uint8_t arrays for data sizes below or
* equal to 8 bits else it is organized as uint16_t arrays.
*
* @param[in] spip pointer to the @p SPIDriver object
* @param[in] n number of words to send
* @param[in] txbuf the pointer to the transmit buffer
*
* @notapi
*/
void spi_lld_send(SPIDriver *spip, size_t n, const void *txbuf) {
spip->rxptr = NULL;
spip->txptr = txbuf;
spip->rxcnt = spip->txcnt = n;
ssp_fifo_preload(spip);
spip->ssp->IMSC = IMSC_ROR | IMSC_RT | IMSC_TX | IMSC_RX;
}
/**
* @brief Ignores data on the SPI bus.
* @details This function transmits a series of idle words on the SPI bus and
* ignores the received data. This function can be invoked even
* when a slave select signal has not been yet asserted.
*
* @param[in] spip pointer to the @p SPIDriver object
* @param[in] n number of words to be ignored
*
* @notapi
*/
void spi_lld_ignore(SPIDriver *spip, size_t n) {
spip->rxptr = NULL;
spip->txptr = NULL;
spip->rxcnt = spip->txcnt = n;
ssp_fifo_preload(spip);
spip->ssp->IMSC = IMSC_ROR | IMSC_RT | IMSC_TX | IMSC_RX;
}
/**
* @brief Exchanges data on the SPI bus.
* @details This asynchronous function starts a simultaneous transmit/receive
* operation.
* @post At the end of the operation the configured callback is invoked.
* @note The buffers are organized as uint8_t arrays for data sizes below or
* equal to 8 bits else it is organized as uint16_t arrays.
*
* @param[in] spip pointer to the @p SPIDriver object
* @param[in] n number of words to be exchanged
* @param[in] txbuf the pointer to the transmit buffer
* @param[out] rxbuf the pointer to the receive buffer
*
* @notapi
*/
void spi_lld_exchange(SPIDriver *spip, size_t n,
const void *txbuf, void *rxbuf) {
spip->spd_rxptr = rxbuf;
spip->spd_txptr = txbuf;
spip->spd_rxcnt = spip->spd_txcnt = n;
ssp_fifo_preload(spip);
spip->spd_ssp->SSP_IMSC = IMSC_ROR | IMSC_RT | IMSC_TX | IMSC_RX;
}