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author | Stephen Caudle <stephen@caudle.info> | 2015-07-27 21:39:45 -0400 |
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committer | Stephen Caudle <stephen@caudle.info> | 2015-07-27 22:42:45 -0400 |
commit | 6202fcbb8b5779f38088540f2c699aeb8d21dc5c (patch) | |
tree | 957aa4337c3fb7705fbea51c59fcd08f0286f874 /os/hal/ports/NRF51/NRF51822/spi_lld.c | |
parent | eab925c4925e10684973c8e725ff66f5c76660de (diff) | |
download | ChibiOS-Contrib-6202fcbb8b5779f38088540f2c699aeb8d21dc5c.tar.gz ChibiOS-Contrib-6202fcbb8b5779f38088540f2c699aeb8d21dc5c.tar.bz2 ChibiOS-Contrib-6202fcbb8b5779f38088540f2c699aeb8d21dc5c.zip |
Add SPI support for nRF51
Diffstat (limited to 'os/hal/ports/NRF51/NRF51822/spi_lld.c')
-rw-r--r-- | os/hal/ports/NRF51/NRF51822/spi_lld.c | 374 |
1 files changed, 374 insertions, 0 deletions
diff --git a/os/hal/ports/NRF51/NRF51822/spi_lld.c b/os/hal/ports/NRF51/NRF51822/spi_lld.c new file mode 100644 index 0000000..7a70c13 --- /dev/null +++ b/os/hal/ports/NRF51/NRF51822/spi_lld.c @@ -0,0 +1,374 @@ +/*
+ Copyright (C) 2015 Stephen Caudle
+
+ 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 NRF51822/spi_lld.c
+ * @brief NRF51822 low level SPI driver code.
+ *
+ * @addtogroup SPI
+ * @{
+ */
+
+#include "hal.h"
+
+#if HAL_USE_SPI || defined(__DOXYGEN__)
+
+/*===========================================================================*/
+/* Driver exported variables. */
+/*===========================================================================*/
+
+#if NRF51_SPI_USE_SPI0 || defined(__DOXYGEN__)
+/** @brief SPI1 driver identifier.*/
+SPIDriver SPID1;
+#endif
+
+#if NRF51_SPI_USE_SPI1 || defined(__DOXYGEN__)
+/** @brief SPI2 driver identifier.*/
+SPIDriver SPID2;
+#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 port_fifo_preload(SPIDriver *spip) {
+ NRF_SPI_Type *port = spip->port;
+
+ if (spip->txcnt > 0 && spip->txptr != NULL)
+ port->TXD = *(uint8_t *)spip->txptr++;
+ else
+ port->TXD = 0xFF;
+ 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) {
+ NRF_SPI_Type *port = spip->port;
+
+ // Clear SPI READY event flag
+ port->EVENTS_READY = 0;
+
+ if (spip->rxptr != NULL) {
+ *(uint8_t *)spip->rxptr++ = port->RXD;
+ }
+ else {
+ (void)port->RXD;
+ if (--spip->rxcnt == 0) {
+ osalDbgAssert(spip->txcnt == 0, "counter out of synch");
+ /* Stops the IRQ sources.*/
+ spip->port->INTENCLR = (SPI_INTENCLR_READY_Clear << SPI_INTENCLR_READY_Pos);
+ /* Portable SPI ISR code defined in the high level driver, note, it is
+ a macro.*/
+ _spi_isr_code(spip);
+ return;
+ }
+ }
+ if (spip->txcnt > 0) {
+ port_fifo_preload(spip);
+ }
+ else {
+ spip->port->INTENCLR = (SPI_INTENCLR_READY_Clear << SPI_INTENCLR_READY_Pos);
+ /* Portable SPI ISR code defined in the high level driver, note, it is
+ a macro.*/
+ _spi_isr_code(spip);
+ }
+}
+
+/*===========================================================================*/
+/* Driver interrupt handlers. */
+/*===========================================================================*/
+
+#if NRF51_SPI_USE_SPI0 || defined(__DOXYGEN__)
+/**
+ * @brief SPI0 interrupt handler.
+ *
+ * @isr
+ */
+CH_IRQ_HANDLER(Vector4C) {
+
+ CH_IRQ_PROLOGUE();
+ serve_interrupt(&SPID1);
+ CH_IRQ_EPILOGUE();
+}
+#endif
+#if NRF51_SPI_USE_SPI1 || defined(__DOXYGEN__)
+/**
+ * @brief SPI1 interrupt handler.
+ *
+ * @isr
+ */
+CH_IRQ_HANDLER(Vector50) {
+
+ CH_IRQ_PROLOGUE();
+ serve_interrupt(&SPID2);
+ CH_IRQ_EPILOGUE();
+}
+#endif
+
+/*===========================================================================*/
+/* Driver exported functions. */
+/*===========================================================================*/
+
+/**
+ * @brief Low level SPI driver initialization.
+ *
+ * @notapi
+ */
+void spi_lld_init(void) {
+
+#if NRF51_SPI_USE_SPI0
+ spiObjectInit(&SPID1);
+ SPID1.port = NRF_SPI0;
+#endif
+#if NRF51_SPI_USE_SPI1
+ spiObjectInit(&SPID2);
+ SPID2.port = NRF_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) {
+ uint32_t config;
+
+ if (spip->state == SPI_STOP) {
+#if NRF51_SPI_USE_SPI0
+ if (&SPID1 == spip)
+ nvicEnableVector(SPI0_TWI0_IRQn, NRF51_SPI_SPI0_IRQ_PRIORITY);
+#endif
+#if NRF51_SPI_USE_SPI1
+ if (&SPID2 == spip)
+ nvicEnableVector(SPI1_TWI1_IRQn, NRF51_SPI_SPI1_IRQ_PRIORITY);
+#endif
+ }
+
+ config = spip->config->lsbfirst ?
+ (SPI_CONFIG_ORDER_LsbFirst << SPI_CONFIG_ORDER_Pos) :
+ (SPI_CONFIG_ORDER_MsbFirst << SPI_CONFIG_ORDER_Pos);
+
+ switch (spip->config->mode) {
+ case 1:
+ config |= (SPI_CONFIG_CPOL_ActiveLow << SPI_CONFIG_CPOL_Pos);
+ config |= (SPI_CONFIG_CPHA_Trailing << SPI_CONFIG_CPHA_Pos);
+ break;
+ case 2:
+ config |= (SPI_CONFIG_CPOL_ActiveHigh << SPI_CONFIG_CPOL_Pos);
+ config |= (SPI_CONFIG_CPHA_Leading << SPI_CONFIG_CPHA_Pos);
+ break;
+ case 3:
+ config |= (SPI_CONFIG_CPOL_ActiveHigh << SPI_CONFIG_CPOL_Pos);
+ config |= (SPI_CONFIG_CPHA_Trailing << SPI_CONFIG_CPHA_Pos);
+ break;
+ default:
+ config |= (SPI_CONFIG_CPOL_ActiveLow << SPI_CONFIG_CPOL_Pos);
+ config |= (SPI_CONFIG_CPHA_Leading << SPI_CONFIG_CPHA_Pos);
+ break;
+ }
+
+ /* Configuration.*/
+ spip->port->CONFIG = config;
+ spip->port->PSELSCK = spip->config->sckpad;
+ spip->port->PSELMOSI = spip->config->mosipad;
+ spip->port->PSELMISO = spip->config->misopad;
+ spip->port->FREQUENCY = spip->config->freq;
+ spip->port->ENABLE = (SPI_ENABLE_ENABLE_Enabled << SPI_ENABLE_ENABLE_Pos);
+
+ /* clear events flag */
+ spip->port->EVENTS_READY = 0;
+}
+
+/**
+ * @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->port->ENABLE = (SPI_ENABLE_ENABLE_Disabled << SPI_ENABLE_ENABLE_Pos);
+ spip->port->INTENCLR = (SPI_INTENCLR_READY_Clear << SPI_INTENCLR_READY_Pos);
+#if NRF51_SPI_USE_SPI0
+ if (&SPID1 == spip)
+ nvicDisableVector(SPI0_TWI0_IRQn);
+#endif
+#if NRF51_SPI_USE_SPI1
+ if (&SPID2 == spip)
+ nvicDisableVector(SPI1_TWI1_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(IOPORT1, 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(IOPORT1, 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;
+ port_fifo_preload(spip);
+ spip->port->INTENSET = (SPI_INTENCLR_READY_Enabled << SPI_INTENCLR_READY_Pos);
+}
+
+/**
+ * @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;
+ port_fifo_preload(spip);
+ spip->port->INTENSET = (SPI_INTENCLR_READY_Enabled << SPI_INTENCLR_READY_Pos);
+}
+
+/**
+ * @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;
+ port_fifo_preload(spip);
+ spip->port->INTENSET = (SPI_INTENCLR_READY_Enabled << SPI_INTENCLR_READY_Pos);
+}
+
+/**
+ * @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;
+ port_fifo_preload(spip);
+ spip->port->INTENSET = (SPI_INTENCLR_READY_Enabled << SPI_INTENCLR_READY_Pos);
+}
+
+/**
+ * @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->port->TXD = (uint8_t)frame;
+ while (spip->port->EVENTS_READY == 0)
+ ;
+ spip->port->EVENTS_READY = 0;
+ return spip->port->RXD;
+}
+
+#endif /* HAL_USE_SPI */
+
+/** @} */
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