diff options
Diffstat (limited to 'os/hal/platforms/AT91SAM7/spi_lld.c')
| -rw-r--r-- | os/hal/platforms/AT91SAM7/spi_lld.c | 397 |
1 files changed, 397 insertions, 0 deletions
diff --git a/os/hal/platforms/AT91SAM7/spi_lld.c b/os/hal/platforms/AT91SAM7/spi_lld.c new file mode 100644 index 000000000..a2ffcfd2e --- /dev/null +++ b/os/hal/platforms/AT91SAM7/spi_lld.c @@ -0,0 +1,397 @@ +/*
+ ChibiOS/RT - Copyright (C) 2006-2013 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 AT91SAM7/spi_lld.c
+ * @brief AT91SAM7 low level SPI driver code.
+ *
+ * @addtogroup SPI
+ * @{
+ */
+
+#include "ch.h"
+#include "hal.h"
+
+#if HAL_USE_SPI || defined(__DOXYGEN__)
+
+/*===========================================================================*/
+/* Driver exported variables. */
+/*===========================================================================*/
+
+#if AT91SAM7_SPI_USE_SPI0 || defined(__DOXYGEN__)
+/** @brief SPI1 driver identifier.*/
+SPIDriver SPID1;
+#endif
+
+#if AT91SAM7_SPI_USE_SPI1 || defined(__DOXYGEN__)
+/** @brief SPI2 driver identifier.*/
+SPIDriver SPID2;
+#endif
+
+/*===========================================================================*/
+/* Driver local variables and types. */
+/*===========================================================================*/
+
+/**
+ * @brief Idle line value.
+ * @details This thing's DMA apparently does not allow to *not* increment
+ * the memory pointer so a buffer filled with ones is required
+ * somewhere.
+ * @note This buffer size also limits the maximum transfer size, 512B,
+ * for @p spiReceive() and @p spiIgnore(). @p spiSend() and
+ * @p spiExchange are not affected.
+ */
+static const uint16_t idle_buf[] = {
+ 0xFFFF, 0xFFFF, 0xFFFF, 0xFFFF, 0xFFFF, 0xFFFF, 0xFFFF, 0xFFFF,
+ 0xFFFF, 0xFFFF, 0xFFFF, 0xFFFF, 0xFFFF, 0xFFFF, 0xFFFF, 0xFFFF,
+ 0xFFFF, 0xFFFF, 0xFFFF, 0xFFFF, 0xFFFF, 0xFFFF, 0xFFFF, 0xFFFF,
+ 0xFFFF, 0xFFFF, 0xFFFF, 0xFFFF, 0xFFFF, 0xFFFF, 0xFFFF, 0xFFFF,
+ 0xFFFF, 0xFFFF, 0xFFFF, 0xFFFF, 0xFFFF, 0xFFFF, 0xFFFF, 0xFFFF,
+ 0xFFFF, 0xFFFF, 0xFFFF, 0xFFFF, 0xFFFF, 0xFFFF, 0xFFFF, 0xFFFF,
+ 0xFFFF, 0xFFFF, 0xFFFF, 0xFFFF, 0xFFFF, 0xFFFF, 0xFFFF, 0xFFFF,
+ 0xFFFF, 0xFFFF, 0xFFFF, 0xFFFF, 0xFFFF, 0xFFFF, 0xFFFF, 0xFFFF,
+ 0xFFFF, 0xFFFF, 0xFFFF, 0xFFFF, 0xFFFF, 0xFFFF, 0xFFFF, 0xFFFF,
+ 0xFFFF, 0xFFFF, 0xFFFF, 0xFFFF, 0xFFFF, 0xFFFF, 0xFFFF, 0xFFFF,
+ 0xFFFF, 0xFFFF, 0xFFFF, 0xFFFF, 0xFFFF, 0xFFFF, 0xFFFF, 0xFFFF,
+ 0xFFFF, 0xFFFF, 0xFFFF, 0xFFFF, 0xFFFF, 0xFFFF, 0xFFFF, 0xFFFF,
+ 0xFFFF, 0xFFFF, 0xFFFF, 0xFFFF, 0xFFFF, 0xFFFF, 0xFFFF, 0xFFFF,
+ 0xFFFF, 0xFFFF, 0xFFFF, 0xFFFF, 0xFFFF, 0xFFFF, 0xFFFF, 0xFFFF,
+ 0xFFFF, 0xFFFF, 0xFFFF, 0xFFFF, 0xFFFF, 0xFFFF, 0xFFFF, 0xFFFF,
+ 0xFFFF, 0xFFFF, 0xFFFF, 0xFFFF, 0xFFFF, 0xFFFF, 0xFFFF, 0xFFFF,
+ 0xFFFF, 0xFFFF, 0xFFFF, 0xFFFF, 0xFFFF, 0xFFFF, 0xFFFF, 0xFFFF,
+ 0xFFFF, 0xFFFF, 0xFFFF, 0xFFFF, 0xFFFF, 0xFFFF, 0xFFFF, 0xFFFF,
+ 0xFFFF, 0xFFFF, 0xFFFF, 0xFFFF, 0xFFFF, 0xFFFF, 0xFFFF, 0xFFFF,
+ 0xFFFF, 0xFFFF, 0xFFFF, 0xFFFF, 0xFFFF, 0xFFFF, 0xFFFF, 0xFFFF,
+ 0xFFFF, 0xFFFF, 0xFFFF, 0xFFFF, 0xFFFF, 0xFFFF, 0xFFFF, 0xFFFF,
+ 0xFFFF, 0xFFFF, 0xFFFF, 0xFFFF, 0xFFFF, 0xFFFF, 0xFFFF, 0xFFFF,
+ 0xFFFF, 0xFFFF, 0xFFFF, 0xFFFF, 0xFFFF, 0xFFFF, 0xFFFF, 0xFFFF,
+ 0xFFFF, 0xFFFF, 0xFFFF, 0xFFFF, 0xFFFF, 0xFFFF, 0xFFFF, 0xFFFF,
+ 0xFFFF, 0xFFFF, 0xFFFF, 0xFFFF, 0xFFFF, 0xFFFF, 0xFFFF, 0xFFFF,
+ 0xFFFF, 0xFFFF, 0xFFFF, 0xFFFF, 0xFFFF, 0xFFFF, 0xFFFF, 0xFFFF,
+ 0xFFFF, 0xFFFF, 0xFFFF, 0xFFFF, 0xFFFF, 0xFFFF, 0xFFFF, 0xFFFF,
+ 0xFFFF, 0xFFFF, 0xFFFF, 0xFFFF, 0xFFFF, 0xFFFF, 0xFFFF, 0xFFFF,
+ 0xFFFF, 0xFFFF, 0xFFFF, 0xFFFF, 0xFFFF, 0xFFFF, 0xFFFF, 0xFFFF,
+ 0xFFFF, 0xFFFF, 0xFFFF, 0xFFFF, 0xFFFF, 0xFFFF, 0xFFFF, 0xFFFF,
+ 0xFFFF, 0xFFFF, 0xFFFF, 0xFFFF, 0xFFFF, 0xFFFF, 0xFFFF, 0xFFFF,
+ 0xFFFF, 0xFFFF, 0xFFFF, 0xFFFF, 0xFFFF, 0xFFFF, 0xFFFF, 0xFFFF
+};
+
+/*===========================================================================*/
+/* Driver local functions. */
+/*===========================================================================*/
+
+/**
+ * @brief Initializes a SPI device.
+ */
+static void spi_init(AT91PS_SPI spi) {
+
+ /* Software reset must be written twice (errata for revision B parts).*/
+ spi->SPI_CR = AT91C_SPI_SWRST;
+ spi->SPI_CR = AT91C_SPI_SWRST;
+ spi->SPI_RCR = 0;
+ spi->SPI_RNCR = 0;
+ spi->SPI_TCR = 0;
+ spi->SPI_TNCR = 0;
+ spi->SPI_PTCR = AT91C_PDC_RXTDIS | AT91C_PDC_TXTDIS;
+ spi->SPI_MR = AT91C_SPI_MSTR | AT91C_SPI_MODFDIS;
+}
+
+#if defined(__GNUC__)
+__attribute__((noinline))
+#endif
+/**
+ * @brief Shared interrupt handling code.
+ *
+ * @param[in] spip pointer to the @p SPIDriver object
+ */
+static void spi_lld_serve_interrupt(SPIDriver *spip) {
+ uint32_t sr = spip->spi->SPI_SR;
+
+ if ((sr & AT91C_SPI_ENDRX) != 0) {
+ (void)spip->spi->SPI_RDR; /* Clears eventual overflow.*/
+ spip->spi->SPI_PTCR = AT91C_PDC_RXTDIS |
+ AT91C_PDC_TXTDIS; /* PDC disabled. */
+ spip->spi->SPI_IDR = AT91C_SPI_ENDRX; /* Interrupt disabled. */
+ spip->spi->SPI_CR = AT91C_SPI_SPIDIS; /* SPI disabled. */
+ /* Portable SPI ISR code defined in the high level driver, note, it is
+ a macro.*/
+ _spi_isr_code(spip);
+ }
+}
+
+/*===========================================================================*/
+/* Driver interrupt handlers. */
+/*===========================================================================*/
+
+#if AT91SAM7_SPI_USE_SPI0 || defined(__DOXYGEN__)
+/**
+ * @brief SPI0 interrupt handler.
+ *
+ * @isr
+ */
+CH_IRQ_HANDLER(SPI0IrqHandler) {
+
+ CH_IRQ_PROLOGUE();
+ spi_lld_serve_interrupt(&SPID1);
+ AT91C_BASE_AIC->AIC_EOICR = 0;
+ CH_IRQ_EPILOGUE();
+}
+#endif
+
+#if AT91SAM7_SPI_USE_SPI1 || defined(__DOXYGEN__)
+/**
+ * @brief SPI1 interrupt handler.
+ *
+ * @isr
+ */
+CH_IRQ_HANDLER(SPI1IrqHandler) {
+
+ CH_IRQ_PROLOGUE();
+ spi_lld_serve_interrupt(&SPID2);
+ AT91C_BASE_AIC->AIC_EOICR = 0;
+ CH_IRQ_EPILOGUE();
+}
+#endif
+
+/*===========================================================================*/
+/* Driver exported functions. */
+/*===========================================================================*/
+
+/**
+ * @brief Low level SPI driver initialization.
+ *
+ * @notapi
+ */
+void spi_lld_init(void) {
+
+#if AT91SAM7_SPI_USE_SPI0
+ spiObjectInit(&SPID1);
+ SPID1.spi = AT91C_BASE_SPI0;
+ spi_init(AT91C_BASE_SPI0);
+ AT91C_BASE_PIOA->PIO_PDR = SPI0_MISO | SPI0_MOSI | SPI0_SCK;
+ AT91C_BASE_PIOA->PIO_ASR = SPI0_MISO | SPI0_MOSI | SPI0_SCK;
+ AT91C_BASE_PIOA->PIO_PPUDR = SPI0_MISO | SPI0_MOSI | SPI0_SCK;
+ AIC_ConfigureIT(AT91C_ID_SPI0,
+ AT91C_AIC_SRCTYPE_HIGH_LEVEL | AT91SAM7_SPI0_PRIORITY,
+ SPI0IrqHandler);
+#endif
+
+#if AT91SAM7_SPI_USE_SPI1
+ spiObjectInit(&SPID2);
+ SPID2.spi = AT91C_BASE_SPI1;
+ spi_init(AT91C_BASE_SPI1);
+ AT91C_BASE_PIOA->PIO_PDR = SPI1_MISO | SPI1_MOSI | SPI1_SCK;
+ AT91C_BASE_PIOA->PIO_BSR = SPI1_MISO | SPI1_MOSI | SPI1_SCK;
+ AT91C_BASE_PIOA->PIO_PPUDR = SPI1_MISO | SPI1_MOSI | SPI1_SCK;
+ AIC_ConfigureIT(AT91C_ID_SPI1,
+ AT91C_AIC_SRCTYPE_HIGH_LEVEL | AT91SAM7_SPI1_PRIORITY,
+ SPI1IrqHandler);
+#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) {
+#if AT91SAM7_SPI_USE_SPI0
+ if (&SPID1 == spip) {
+ /* Clock activation.*/
+ AT91C_BASE_PMC->PMC_PCER = (1 << AT91C_ID_SPI0);
+ /* Enables associated interrupt vector.*/
+ AIC_EnableIT(AT91C_ID_SPI0);
+ }
+#endif
+#if AT91SAM7_SPI_USE_SPI1
+ if (&SPID2 == spip) {
+ /* Clock activation.*/
+ AT91C_BASE_PMC->PMC_PCER = (1 << AT91C_ID_SPI1);
+ /* Enables associated interrupt vector.*/
+ AIC_EnableIT(AT91C_ID_SPI1);
+ }
+#endif
+ }
+ /* Configuration.*/
+ spip->spi->SPI_CSR[0] = spip->config->csr;
+}
+
+/**
+ * @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) {
+#if AT91SAM7_SPI_USE_SPI0
+ if (&SPID1 == spip) {
+ AT91C_BASE_PMC->PMC_PCDR = (1 << AT91C_ID_SPI0);
+ AIC_DisableIT(AT91C_ID_SPI0);
+ }
+#endif
+#if AT91SAM7_SPI_USE_SPI1
+ if (&SPID1 == spip) {
+ AT91C_BASE_PMC->PMC_PCDR = (1 << AT91C_ID_SPI1);
+ AIC_DisableIT(AT91C_ID_SPI0);
+ }
+#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->spi->SPI_TCR = n;
+ spip->spi->SPI_RCR = n;
+ spip->spi->SPI_TPR = (AT91_REG)idle_buf;
+ spip->spi->SPI_RPR = (AT91_REG)idle_buf;
+ spip->spi->SPI_IER = AT91C_SPI_ENDRX;
+ spip->spi->SPI_CR = AT91C_SPI_SPIEN;
+ spip->spi->SPI_PTCR = AT91C_PDC_RXTEN | AT91C_PDC_TXTEN;
+}
+
+/**
+ * @brief Exchanges data on the SPI bus.
+ * @details This function performs a simultaneous transmit/receive operation.
+ * @note The buffers are organized as uint8_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->spi->SPI_TCR = n;
+ spip->spi->SPI_RCR = n;
+ spip->spi->SPI_TPR = (AT91_REG)txbuf;
+ spip->spi->SPI_RPR = (AT91_REG)rxbuf;
+ spip->spi->SPI_IER = AT91C_SPI_ENDRX;
+ spip->spi->SPI_CR = AT91C_SPI_SPIEN;
+ spip->spi->SPI_PTCR = AT91C_PDC_RXTEN | AT91C_PDC_TXTEN;
+}
+
+/**
+ * @brief Sends data over the SPI bus.
+ * @note The buffers are organized as uint8_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->spi->SPI_TCR = n;
+ spip->spi->SPI_RCR = n;
+ spip->spi->SPI_TPR = (AT91_REG)txbuf;
+ spip->spi->SPI_RPR = (AT91_REG)idle_buf;
+ spip->spi->SPI_IER = AT91C_SPI_ENDRX;
+ spip->spi->SPI_CR = AT91C_SPI_SPIEN;
+ spip->spi->SPI_PTCR = AT91C_PDC_RXTEN | AT91C_PDC_TXTEN;
+}
+
+/**
+ * @brief Receives data from the SPI bus.
+ * @note The buffers are organized as uint8_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->spi->SPI_TCR = n;
+ spip->spi->SPI_RCR = n;
+ spip->spi->SPI_TPR = (AT91_REG)idle_buf;
+ spip->spi->SPI_RPR = (AT91_REG)rxbuf;
+ spip->spi->SPI_IER = AT91C_SPI_ENDRX;
+ spip->spi->SPI_CR = AT91C_SPI_SPIEN;
+ spip->spi->SPI_PTCR = AT91C_PDC_RXTEN | AT91C_PDC_TXTEN;
+}
+
+/**
+ * @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->spi->SPI_CR = AT91C_SPI_SPIEN;
+ spip->spi->SPI_TDR = frame;
+ while ((spip->spi->SPI_SR & AT91C_SPI_RDRF) == 0)
+ ;
+ return spip->spi->SPI_RDR;
+}
+
+#endif /* HAL_USE_SPI */
+
+/** @} */
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