diff options
Diffstat (limited to 'os/hal/ports/KINETIS/K20x/spi_lld.c')
| -rw-r--r-- | os/hal/ports/KINETIS/K20x/spi_lld.c | 382 |
1 files changed, 382 insertions, 0 deletions
diff --git a/os/hal/ports/KINETIS/K20x/spi_lld.c b/os/hal/ports/KINETIS/K20x/spi_lld.c new file mode 100644 index 000000000..ee645e686 --- /dev/null +++ b/os/hal/ports/KINETIS/K20x/spi_lld.c @@ -0,0 +1,382 @@ +/*
+ ChibiOS/HAL - Copyright (C) 2006-2014 Giovanni Di Sirio
+
+ Licensed under the Apache License, Version 2.0 (the "License");
+ you may not use this file except in compliance with the License.
+ You may obtain a copy of the License at
+
+ http://www.apache.org/licenses/LICENSE-2.0
+
+ Unless required by applicable law or agreed to in writing, software
+ distributed under the License is distributed on an "AS IS" BASIS,
+ WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ See the License for the specific language governing permissions and
+ limitations under the License.
+*/
+
+/**
+ * @file KINETIS/spi_lld.c
+ * @brief KINETIS SPI subsystem low level driver source.
+ *
+ * @addtogroup SPI
+ * @{
+ */
+
+#include "hal.h"
+
+#if HAL_USE_SPI || defined(__DOXYGEN__)
+
+/*===========================================================================*/
+/* Driver local definitions. */
+/*===========================================================================*/
+
+/*===========================================================================*/
+/* Driver exported variables. */
+/*===========================================================================*/
+
+/** @brief SPI0 driver identifier.*/
+#if KINETIS_SPI_USE_SPI0 || defined(__DOXYGEN__)
+SPIDriver SPID1;
+#endif
+
+/*===========================================================================*/
+/* Driver local variables and types. */
+/*===========================================================================*/
+
+/*===========================================================================*/
+/* Driver local functions. */
+/*===========================================================================*/
+
+static void spi_start_xfer(SPIDriver *spip, bool polling)
+{
+ /*
+ * Enable the DSPI peripheral in master mode.
+ * On receive overflow, new data will overwrite old data.
+ * Set slave selects to be active low.
+ * Clear the TX and RX FIFOs.
+ * */
+ spip->spi->MCR = SPIx_MCR_MSTR |
+ SPIx_MCR_ROOE |
+ SPIx_MCR_PCSIS(KINETIS_SPI_PCS_ALL) |
+ SPIx_MCR_CLR_TXF | SPIx_MCR_CLR_RXF;
+
+ /* If we are not polling then enable interrupts */
+ if (!polling) {
+
+ /* Enable transmit fill, receive and end of queue interrupts */
+ spip->spi->RSER = SPIx_RSER_TFFF_RE | SPIx_RSER_RFDF_RE |
+ SPIx_RSER_EOQF_RE;
+
+ }
+}
+
+static void spi_stop_xfer(SPIDriver *spip)
+{
+ /* Halt the DSPI peripheral */
+ spip->spi->MCR = SPIx_MCR_MSTR |
+ SPIx_MCR_ROOE |
+ SPIx_MCR_PCSIS(KINETIS_SPI_PCS_ALL) |
+ SPIx_MCR_CLR_TXF | SPIx_MCR_CLR_RXF |
+ SPIx_MCR_HALT;
+
+ /* Clear all interrupt enables */
+ spip->spi->RSER = 0;
+
+ /* Clear all the flags which are currently set. */
+ spip->spi->SR |= spip->spi->SR;
+}
+
+/*===========================================================================*/
+/* Driver interrupt handlers. */
+/*===========================================================================*/
+
+OSAL_IRQ_HANDLER(Vector70) {
+ OSAL_IRQ_PROLOGUE();
+
+ SPIDriver *spip = &SPID1;
+ uint32_t sr = spip->spi->SR;
+
+ /* Handle Receive FIFO Drain interrupt */
+ if (sr & SPIx_SR_RFDF) {
+
+ /* Pop the data out of the fifo */
+ uint8_t data = spip->spi->POPR;
+
+ /* If we have an rxbuf and it has space then store the data */
+ if (spip->rxbuf && spip->rxidx < spip->nbytes) {
+ spip->rxbuf[spip->rxidx++] = data;
+ }
+
+ /* Clear the Receive FIFO Drain Flag */
+ spip->spi->SR = SPIx_SR_RFDF;
+ }
+
+ /* Handle End of Queue interrupt */
+ if (sr & SPIx_SR_EOQF) {
+
+ spip->spi->SR = SPIx_SR_EOQF;
+
+ spi_stop_xfer(spip);
+
+ _spi_isr_code(spip);
+ }
+
+ /* Handle Transmit FIFO Fill interrupt */
+ if (sr & SPIx_SR_TFFF) {
+
+ /* The data to send is either the next tx byte or a filler byte */
+ uint8_t data = spip->txbuf ? spip->txbuf[spip->txidx] : 0x00;
+
+ /* Calculate the number of bytes remaining and increment the index */
+ size_t n = spip->nbytes - spip->txidx++;
+
+ /* Push the data into the FIFO, CONT if more bytes, EOQ if last byte */
+ spip->spi->PUSHR = (n > 1 ? SPIx_PUSHR_CONT : SPIx_PUSHR_EOQ) |
+ SPIx_PUSHR_PCS(spip->config->pcs) |
+ SPIx_PUSHR_TXDATA(data);
+
+ /* Clear the Transmit FIFO Fill Flag */
+ spip->spi->SR = SPIx_SR_TFFF;
+ }
+
+ OSAL_IRQ_EPILOGUE();
+}
+
+/*===========================================================================*/
+/* Driver exported functions. */
+/*===========================================================================*/
+
+/**
+ * @brief Low level SPI driver initialization.
+ *
+ * @notapi
+ */
+void spi_lld_init(void) {
+
+ nvicEnableVector(SPI0_IRQn, KINETIS_SPI_SPI0_IRQ_PRIORITY);
+
+#if KINETIS_SPI_USE_SPI0
+ spiObjectInit(&SPID1);
+#endif
+
+}
+
+/**
+ * @brief Configures and activates the SPI peripheral.
+ *
+ * @param[in] spip pointer to the @p SPIDriver object
+ *
+ * @notapi
+ */
+void spi_lld_start(SPIDriver *spip) {
+
+ /* If in stopped state then enables the SPI and DMA clocks.*/
+ if (spip->state == SPI_STOP) {
+
+#if KINETIS_SPI_USE_SPI0
+ if (&SPID1 == spip) {
+
+ /* Enable the clock for SPI0 */
+ SIM->SCGC6 |= SIM_SCGC6_SPI0;
+
+ SPID1.spi = SPI0;
+
+ if (spip->config->tar0) {
+ spip->spi->CTAR[0] = spip->config->tar0;
+ } else {
+ spip->spi->CTAR[0] = KINETIS_SPI_TAR0_DEFAULT;
+ }
+
+ spip->spi->CTAR[1] = KINETIS_SPI_TAR1_DEFAULT;
+ }
+#endif
+ }
+
+ /* SPI setup and enable.*/
+}
+
+/**
+ * @brief Deactivates the SPI peripheral.
+ *
+ * @param[in] spip pointer to the @p SPIDriver object
+ *
+ * @notapi
+ */
+void spi_lld_stop(SPIDriver *spip) {
+
+ /* If in ready state then disables the SPI clock.*/
+ if (spip->state == SPI_READY) {
+
+ /* Disable the clock for SPI0 */
+ SIM->SCGC6 &= ~SIM_SCGC6_SPI0;
+
+#if KINETIS_SPI_USE_SPI0
+ if (&SPID1 == spip) {
+ /* SPI halt.*/
+ spip->spi->MCR |= SPIx_MCR_HALT;
+ }
+#endif
+ }
+}
+
+/**
+ * @brief Asserts the slave select signal and prepares for transfers.
+ *
+ * @param[in] spip pointer to the @p SPIDriver object
+ *
+ * @notapi
+ */
+void spi_lld_select(SPIDriver *spip) {
+
+ /* If we are not using the DSPI managed chip select then assert the SS */
+ if (!spip->config->pcs) {
+ palClearPad(spip->config->ssport, spip->config->sspad);
+ }
+}
+
+/**
+ * @brief Deasserts the slave select signal.
+ * @details The previously selected peripheral is unselected.
+ * This has no effect if we are using the KINETIS PCS mode to
+ * manage slave select.
+ *
+ * @param[in] spip pointer to the @p SPIDriver object
+ *
+ * @notapi
+ */
+void spi_lld_unselect(SPIDriver *spip) {
+
+ /* If we are not using the DSPI managed chip select then deassert the SS */
+ if (!spip->config->pcs) {
+ palSetPad(spip->config->ssport, spip->config->sspad);
+ }
+}
+
+/**
+ * @brief Ignores data on the SPI bus.
+ * @details This asynchronous function starts the transmission of a series of
+ * idle words on the SPI bus and ignores the received data.
+ * @post At the end of the operation the configured callback is invoked.
+ *
+ * @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->nbytes = n;
+ spip->rxbuf = NULL;
+ spip->rxidx = 0;
+ spip->txbuf = NULL;
+ spip->txidx = 0;
+
+ spi_start_xfer(spip, false);
+}
+
+/**
+ * @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->nbytes = n;
+ spip->rxbuf = rxbuf;
+ spip->rxidx = 0;
+ spip->txbuf = txbuf;
+ spip->txidx = 0;
+
+ spi_start_xfer(spip, false);
+}
+
+/**
+ * @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->nbytes = n;
+ spip->rxbuf = NULL;
+ spip->rxidx = 0;
+ spip->txbuf = (void *)txbuf;
+ spip->txidx = 0;
+
+ spi_start_xfer(spip, false);
+}
+
+/**
+ * @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->nbytes = n;
+ spip->rxbuf = rxbuf;
+ spip->rxidx = 0;
+ spip->txbuf = NULL;
+ spip->txidx = 0;
+
+ spi_start_xfer(spip, false);
+}
+
+/**
+ * @brief Exchanges one frame using a polled wait.
+ * @details This synchronous function exchanges one frame using a polled
+ * synchronization method. This function is useful when exchanging
+ * small amount of data on high speed channels, usually in this
+ * situation is much more efficient just wait for completion using
+ * polling than suspending the thread waiting for an interrupt.
+ *
+ * @param[in] spip pointer to the @p SPIDriver object
+ * @param[in] frame the data frame to send over the SPI bus
+ * @return The received data frame from the SPI bus.
+ */
+uint16_t spi_lld_polled_exchange(SPIDriver *spip, uint16_t frame) {
+
+ spi_start_xfer(spip, true);
+
+ spip->spi->PUSHR = SPIx_PUSHR_PCS(0x10) | SPIx_PUSHR_TXDATA(frame);
+
+ while ((spip->spi->SR & SPIx_SR_RFDF) == 0)
+ ;
+
+ frame = spip->spi->POPR;
+
+ spi_stop_xfer(spip);
+
+ return frame;
+}
+
+#endif /* HAL_USE_SPI */
+
+/** @} */
|