diff options
Diffstat (limited to 'os/hal/ports/LPC/LPC214x/spi_lld.c')
| -rw-r--r-- | os/hal/ports/LPC/LPC214x/spi_lld.c | 337 |
1 files changed, 337 insertions, 0 deletions
diff --git a/os/hal/ports/LPC/LPC214x/spi_lld.c b/os/hal/ports/LPC/LPC214x/spi_lld.c new file mode 100644 index 000000000..398518f34 --- /dev/null +++ b/os/hal/ports/LPC/LPC214x/spi_lld.c @@ -0,0 +1,337 @@ +/*
+ ChibiOS - 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 LPC214x/spi_lld.c
+ * @brief LPC214x low level SPI driver code.
+ *
+ * @addtogroup SPI
+ * @{
+ */
+
+#include "hal.h"
+
+#if HAL_USE_SPI || defined(__DOXYGEN__)
+
+/*===========================================================================*/
+/* Driver exported variables. */
+/*===========================================================================*/
+
+#if LPC214x_SPI_USE_SSP || defined(__DOXYGEN__)
+/** @brief SPI1 driver identifier.*/
+SPIDriver SPID1;
+#endif
+
+/*===========================================================================*/
+/* Driver local variables and types. */
+/*===========================================================================*/
+
+/*===========================================================================*/
+/* Driver local functions. */
+/*===========================================================================*/
+
+/**
+ * @brief Preloads the transmit FIFO.
+ *
+ * @param[in] spip pointer to the @p SPIDriver object
+ */
+static void ssp_fifo_preload(SPIDriver *spip) {
+ SSP *ssp = spip->ssp;
+ uint32_t n = spip->txcnt > LPC214x_SSP_FIFO_DEPTH ?
+ LPC214x_SSP_FIFO_DEPTH : spip->txcnt;
+
+ while(((ssp->SSP_SR & SR_TNF) != 0) && (n > 0)) {
+ if (spip->txptr != NULL) {
+ if ((ssp->SSP_CR0 & CR0_DSSMASK) > CR0_DSS8BIT)
+ ssp->SSP_DR = *(uint16_t *)spip->txptr++;
+ else
+ ssp->SSP_DR = *(uint8_t *)spip->txptr++;
+ }
+ else
+ ssp->SSP_DR = 0xFFFFFFFF;
+ n--;
+ spip->txcnt--;
+ }
+}
+
+#if defined(__GNUC__)
+__attribute__((noinline))
+#endif
+/**
+ * @brief Common IRQ handler.
+ *
+ * @param[in] spip pointer to the @p SPIDriver object
+ */
+static void serve_interrupt(SPIDriver *spip) {
+ SSP *ssp = spip->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->rxptr != NULL) {
+ if ((ssp->SSP_CR0 & CR0_DSSMASK) > CR0_DSS8BIT)
+ *(uint16_t *)spip->rxptr++ = ssp->SSP_DR;
+ else
+ *(uint8_t *)spip->rxptr++ = ssp->SSP_DR;
+ }
+ else
+ (void)ssp->SSP_DR;
+ if (--spip->rxcnt == 0) {
+ osalDbgAssert(spip->txcnt == 0, "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->txcnt == 0)
+ ssp->SSP_IMSC = IMSC_ROR | IMSC_RT | IMSC_RX;
+}
+
+/*===========================================================================*/
+/* Driver interrupt handlers. */
+/*===========================================================================*/
+
+#if LPC214x_SPI_USE_SSP || defined(__DOXYGEN__)
+/**
+ * @brief SPI1 interrupt handler.
+ *
+ * @isr
+ */
+CH_IRQ_HANDLER(SPI1IrqHandler) {
+
+ CH_IRQ_PROLOGUE();
+
+ serve_interrupt(&SPID1);
+ VICVectAddr = 0;
+
+ CH_IRQ_EPILOGUE();
+}
+#endif
+
+/*===========================================================================*/
+/* Driver exported functions. */
+/*===========================================================================*/
+
+/**
+ * @brief Low level SPI driver initialization.
+ *
+ * @notapi
+ */
+void spi_lld_init(void) {
+
+#if LPC214x_SPI_USE_SSP
+ spiObjectInit(&SPID1);
+ SPID1.ssp = SSPBase;
+ SetVICVector(SPI1IrqHandler, LPC214x_SPI_SSP_IRQ_PRIORITY, SOURCE_SPI1);
+#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 (spip->state == SPI_STOP) {
+ /* Clock activation.*/
+#if LPC214x_SPI_USE_SSP
+ if (&SPID1 == spip) {
+ PCONP = (PCONP & PCALL) | PCSPI1;
+ VICIntEnable = INTMASK(SOURCE_SPI1);
+ }
+#endif
+ }
+ /* Configuration.*/
+ spip->ssp->SSP_CR1 = 0;
+ /* Emptying the receive FIFO, it happens to not be empty while debugging.*/
+ while (spip->ssp->SSP_SR & SR_RNE)
+ (void) spip->ssp->SSP_DR;
+ spip->ssp->SSP_ICR = ICR_RT | ICR_ROR;
+ spip->ssp->SSP_CR0 = spip->config->cr0;
+ spip->ssp->SSP_CPSR = spip->config->cpsr;
+ spip->ssp->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->SSP_CR1 = 0;
+ spip->ssp->SSP_CR0 = 0;
+ spip->ssp->SSP_CPSR = 0;
+#if LPC214x_SPI_USE_SSP
+ if (&SPID1 == spip) {
+ PCONP = (PCONP & PCALL) & ~PCSPI1;
+ VICIntEnClear = INTMASK(SOURCE_SPI1);
+ }
+#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->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->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->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->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->SSP_DR = (uint32_t)frame;
+ while ((spip->ssp->SSP_SR & SR_RNE) == 0)
+ ;
+ return (uint16_t)spip->ssp->SSP_DR;
+}
+
+#endif /* HAL_USE_SPI */
+
+/** @} */
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