diff options
Diffstat (limited to 'os/hal/platforms/LPC11Uxx/spi_lld.c')
| -rw-r--r-- | os/hal/platforms/LPC11Uxx/spi_lld.c | 395 |
1 files changed, 395 insertions, 0 deletions
diff --git a/os/hal/platforms/LPC11Uxx/spi_lld.c b/os/hal/platforms/LPC11Uxx/spi_lld.c new file mode 100644 index 000000000..49fcf1913 --- /dev/null +++ b/os/hal/platforms/LPC11Uxx/spi_lld.c @@ -0,0 +1,395 @@ +/*
+ ChibiOS/RT - Copyright (C) 2006,2007,2008,2009,2010,
+ 2011,2012 Giovanni Di Sirio.
+
+ This file is part of ChibiOS/RT.
+
+ ChibiOS/RT is free software; you can redistribute it and/or modify
+ it under the terms of the GNU General Public License as published by
+ the Free Software Foundation; either version 3 of the License, or
+ (at your option) any later version.
+
+ ChibiOS/RT is distributed in the hope that it will be useful,
+ but WITHOUT ANY WARRANTY; without even the implied warranty of
+ MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ GNU General Public License for more details.
+
+ You should have received a copy of the GNU General Public License
+ along with this program. If not, see <http://www.gnu.org/licenses/>.
+*/
+
+/**
+ * @file LPC11Uxx/spi_lld.c
+ * @brief LPC11Uxx low level SPI driver code.
+ *
+ * @addtogroup SPI
+ * @{
+ */
+
+#include "ch.h"
+#include "hal.h"
+
+#if HAL_USE_SPI || defined(__DOXYGEN__)
+
+/*===========================================================================*/
+/* Driver exported variables. */
+/*===========================================================================*/
+
+#if LPC_SPI_USE_SSP0 || defined(__DOXYGEN__)
+/** @brief SPI1 driver identifier.*/
+SPIDriver SPID1;
+#endif
+
+#if LPC_SPI_USE_SSP1 || defined(__DOXYGEN__)
+/** @brief SPI2 driver identifier.*/
+SPIDriver SPID2;
+#endif
+
+/*===========================================================================*/
+/* Driver local variables. */
+/*===========================================================================*/
+
+/*===========================================================================*/
+/* Driver local functions. */
+/*===========================================================================*/
+
+/**
+ * @brief Preloads the transmit FIFO.
+ *
+ * @param[in] spip pointer to the @p SPIDriver object
+ */
+static void ssp_fifo_preload(SPIDriver *spip) {
+ LPC_SSPx_Type *ssp = spip->ssp;
+ uint32_t n = spip->txcnt > LPC_SSP_FIFO_DEPTH ?
+ LPC_SSP_FIFO_DEPTH : spip->txcnt;
+
+ while(((ssp->SR & SR_TNF) != 0) && (n > 0)) {
+ if (spip->txptr != NULL) {
+ if ((ssp->CR0 & CR0_DSSMASK) > CR0_DSS8BIT) {
+ const uint16_t *p = spip->txptr;
+ ssp->DR = *p++;
+ spip->txptr = p;
+ }
+ else {
+ const uint8_t *p = spip->txptr;
+ ssp->DR = *p++;
+ spip->txptr = p;
+ }
+ }
+ else
+ ssp->DR = 0xFFFFFFFF;
+ n--;
+ spip->txcnt--;
+ }
+}
+
+/**
+ * @brief Common IRQ handler.
+ *
+ * @param[in] spip pointer to the @p SPIDriver object
+ */
+static void spi_serve_interrupt(SPIDriver *spip) {
+ LPC_SSPx_Type *ssp = spip->ssp;
+
+ if ((ssp->MIS & MIS_ROR) != 0) {
+ /* The overflow condition should never happen because priority is given
+ to receive but a hook macro is provided anyway...*/
+ LPC_SPI_SSP_ERROR_HOOK(spip);
+ }
+ ssp->ICR = ICR_RT | ICR_ROR;
+ while ((ssp->SR & SR_RNE) != 0) {
+ if (spip->rxptr != NULL) {
+ if ((ssp->CR0 & CR0_DSSMASK) > CR0_DSS8BIT) {
+ uint16_t *p = spip->rxptr;
+ *p++ = ssp->DR;
+ spip->rxptr = p;
+ }
+ else {
+ uint8_t *p = spip->rxptr;
+ *p++ = ssp->DR;
+ spip->rxptr = p;
+ }
+ }
+ else
+ (void)ssp->DR;
+ if (--spip->rxcnt == 0) {
+ chDbgAssert(spip->txcnt == 0,
+ "spi_serve_interrupt(), #1", "counter out of synch");
+ /* Stops the IRQ sources.*/
+ 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->txcnt == 0)
+ ssp->IMSC = IMSC_ROR | IMSC_RT | IMSC_RX;
+}
+
+/*===========================================================================*/
+/* Driver interrupt handlers. */
+/*===========================================================================*/
+
+#if LPC_SPI_USE_SSP0 || defined(__DOXYGEN__)
+/**
+ * @brief SSP0 interrupt handler.
+ *
+ * @isr
+ */
+CH_IRQ_HANDLER(Vector90) {
+
+ CH_IRQ_PROLOGUE();
+
+ spi_serve_interrupt(&SPID1);
+
+ CH_IRQ_EPILOGUE();
+}
+#endif
+
+#if LPC_SPI_USE_SSP1 || defined(__DOXYGEN__)
+/**
+ * @brief SSP1 interrupt handler.
+ *
+ * @isr
+ */
+CH_IRQ_HANDLER(Vector78) {
+
+ CH_IRQ_PROLOGUE();
+
+ spi_serve_interrupt(&SPID2);
+
+ CH_IRQ_EPILOGUE();
+}
+#endif
+
+/*===========================================================================*/
+/* Driver exported functions. */
+/*===========================================================================*/
+
+/**
+ * @brief Low level SPI driver initialization.
+ *
+ * @notapi
+ */
+void spi_lld_init(void) {
+
+#if LPC_SPI_USE_SSP0
+ spiObjectInit(&SPID1);
+ SPID1.ssp = LPC_SSP0;
+#endif /* LPC_SPI_USE_SSP0 */
+
+#if LPC_SPI_USE_SSP1
+ spiObjectInit(&SPID2);
+ SPID2.ssp = LPC_SSP1;
+#endif /* LPC_SPI_USE_SSP0 */
+}
+
+/**
+ * @brief Configures and activates the SPI peripheral.
+ *
+ * @param[in] spip pointer to the @p SPIDriver object
+ *
+ * @notapi
+ */
+void spi_lld_start(SPIDriver *spip) {
+
+ if (spip->state == SPI_STOP) {
+ /* Clock activation.*/
+#if LPC_SPI_USE_SSP0
+ if (&SPID1 == spip) {
+ LPC_SYSCON->SSP0CLKDIV = LPC_SPI_SSP0CLKDIV;
+ LPC_SYSCON->SYSAHBCLKCTRL |= (1 << 11);
+ LPC_SYSCON->PRESETCTRL |= 1;
+ nvicEnableVector(SSP0_IRQn,
+ CORTEX_PRIORITY_MASK(LPC_SPI_SSP0_IRQ_PRIORITY));
+ }
+#endif
+#if LPC_SPI_USE_SSP1
+ if (&SPID2 == spip) {
+ LPC_SYSCON->SSP1CLKDIV = LPC_SPI_SSP1CLKDIV;
+ LPC_SYSCON->SYSAHBCLKCTRL |= (1 << 18);
+ LPC_SYSCON->PRESETCTRL |= 4;
+ nvicEnableVector(SSP1_IRQn,
+ CORTEX_PRIORITY_MASK(LPC_SPI_SSP1_IRQ_PRIORITY));
+ }
+#endif
+ }
+ /* Configuration.*/
+ spip->ssp->CR1 = 0;
+ spip->ssp->ICR = ICR_RT | ICR_ROR;
+ spip->ssp->CR0 = spip->config->cr0;
+ spip->ssp->CPSR = spip->config->cpsr;
+ spip->ssp->CR1 = CR1_SSE;
+}
+
+/**
+ * @brief Deactivates the SPI peripheral.
+ *
+ * @param[in] spip pointer to the @p SPIDriver object
+ *
+ * @notapi
+ */
+void spi_lld_stop(SPIDriver *spip) {
+
+ if (spip->state != SPI_STOP) {
+ spip->ssp->CR1 = 0;
+ spip->ssp->CR0 = 0;
+ spip->ssp->CPSR = 0;
+#if LPC_SPI_USE_SSP0
+ if (&SPID1 == spip) {
+ LPC_SYSCON->PRESETCTRL &= ~1;
+ LPC_SYSCON->SYSAHBCLKCTRL &= ~(1 << 11);
+ LPC_SYSCON->SSP0CLKDIV = 0;
+ nvicDisableVector(SSP0_IRQn);
+ }
+#endif
+#if LPC_SPI_USE_SSP1
+ if (&SPID2 == spip) {
+ LPC_SYSCON->PRESETCTRL &= ~4;
+ LPC_SYSCON->SYSAHBCLKCTRL &= ~(1 << 18);
+ LPC_SYSCON->SSP1CLKDIV = 0;
+ nvicDisableVector(SSP1_IRQn);
+ }
+#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) {
+
+ palClearPad(spip->config->ssport, spip->config->sspad);
+}
+
+/**
+ * @brief Deasserts the slave select signal.
+ * @details The previously selected peripheral is unselected.
+ *
+ * @param[in] spip pointer to the @p SPIDriver object
+ *
+ * @notapi
+ */
+void spi_lld_unselect(SPIDriver *spip) {
+
+ palSetPad(spip->config->ssport, spip->config->sspad);
+}
+
+/**
+ * @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->rxptr = rxbuf;
+ spip->txptr = txbuf;
+ 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 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 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) {
+
+ spip->ssp->DR = (uint32_t)frame;
+ while ((spip->ssp->SR & SR_RNE) == 0)
+ ;
+ return (uint16_t)spip->ssp->DR;
+}
+
+#endif /* HAL_USE_SPI */
+
+/** @} */
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