diff options
Diffstat (limited to 'os/hal/platforms/STM8S/spi_lld.c')
| -rw-r--r-- | os/hal/platforms/STM8S/spi_lld.c | 290 |
1 files changed, 290 insertions, 0 deletions
diff --git a/os/hal/platforms/STM8S/spi_lld.c b/os/hal/platforms/STM8S/spi_lld.c new file mode 100644 index 000000000..4accd6cd0 --- /dev/null +++ b/os/hal/platforms/STM8S/spi_lld.c @@ -0,0 +1,290 @@ +/*
+ ChibiOS/RT - Copyright (C) 2006,2007,2008,2009,2010 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 STM8/spi_lld.c
+ * @brief STM8 low level SPI driver code.
+ *
+ * @addtogroup SPI
+ * @{
+ */
+
+#include "ch.h"
+#include "hal.h"
+
+#if HAL_USE_SPI || defined(__DOXYGEN__)
+
+/*===========================================================================*/
+/* Driver exported variables. */
+/*===========================================================================*/
+
+#if STM8_SPI_USE_SPI || defined(__DOXYGEN__)
+/** @brief SPI1 driver identifier.*/
+SPIDriver SPID1;
+#endif
+
+/*===========================================================================*/
+/* Driver local variables. */
+/*===========================================================================*/
+
+/*===========================================================================*/
+/* Driver local functions. */
+/*===========================================================================*/
+
+/*===========================================================================*/
+/* Driver interrupt handlers. */
+/*===========================================================================*/
+
+#if STM8_SPI_USE_SPI || defined(__DOXYGEN__)
+/**
+ * @brief IRQ 10 service routine.
+ *
+ * @isr
+ */
+CH_IRQ_HANDLER(10) {
+
+ CH_IRQ_PROLOGUE();
+
+ if ((SPI->SR & SPI_SR_OVR) != 0) {
+ /* The overflow condition should never happen because priority is given
+ to receive but a hook macro is provided anyway...*/
+ STM8_SPI_ERROR_HOOK(&SPID1);
+ }
+ /* Handling the DR register like it is a FIFO with depth>1 in order to
+ handle the case where a frame arrives immediately after reading the
+ DR register.*/
+ while ((SPI->SR & SPI_SR_RXNE) != 0) {
+ if (SPID1.spd_rxptr != NULL)
+ *SPID1.spd_rxptr++ = SPI->DR;
+ else
+ (void)SPI->DR;
+ if (--SPID1.spd_rxcnt == 0) {
+ chDbgAssert(SPID1.spd_txcnt == 0,
+ "IRQ10, #1", "counter out of synch");
+ /* Stops all the IRQ sources.*/
+ SPI->ICR = 0;
+ /* Portable SPI ISR code defined in the high level driver, note, it
+ is a macro.*/
+ _spi_isr_code(&SPID1);
+ /* Goto because it is mandatory to go through the epilogue, cannot
+ just return.*/
+ goto exit_isr;
+ }
+ }
+ /* Loading the DR register.*/
+ if ((SPI->SR & SPI_SR_TXE) != 0) {
+ if (SPID1.spd_txptr != NULL)
+ SPI->DR = *SPID1.spd_txptr++;
+ else
+ SPI->DR = 0xFF;
+ }
+
+exit_isr:
+ CH_IRQ_EPILOGUE();
+}
+#endif
+
+/*===========================================================================*/
+/* Driver exported functions. */
+/*===========================================================================*/
+
+/**
+ * @brief Low level SPI driver initialization.
+ *
+ * @notapi
+ */
+void spi_lld_init(void) {
+
+#if STM8_SPI_USE_SPI
+ spiObjectInit(&SPID1);
+#endif /* STM8_SPI_USE_SPI */
+}
+
+/**
+ * @brief Configures and activates the SPI peripheral.
+ *
+ * @param[in] spip pointer to the @p SPIDriver object
+ *
+ * @notapi
+ */
+void spi_lld_start(SPIDriver *spip) {
+
+ /* Clock activation.*/
+ CLK->PCKENR1 |= CLK_PCKENR1_SPI; /* PCKEN11, clock source. */
+
+ /* Configuration.*/
+ SPI->CR2 = 0;
+ SPI->CR1 = spip->spd_config->spc_cr1 | SPI_CR1_MSTR | SPI_CR1_SPE;
+}
+
+/**
+ * @brief Deactivates the SPI peripheral.
+ *
+ * @param[in] spip pointer to the @p SPIDriver object
+ *
+ * @notapi
+ */
+void spi_lld_stop(SPIDriver *spip) {
+
+ (void)spip;
+
+ /* Reset state.*/
+ SPI->CR1 = 0;
+ SPI->CR2 = 0;
+ SPI->ICR = 0;
+
+ /* Clock de-activation.*/
+ CLK->PCKENR1 &= (uint8_t)~CLK_PCKENR1_SPI; /* PCKEN11, clock source. */
+}
+
+/**
+ * @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->spd_config->spc_ssport, spip->spd_config->spc_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->spd_config->spc_ssport, spip->spd_config->spc_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->spd_rxptr = NULL;
+ spip->spd_txptr = NULL;
+ spip->spd_rxcnt = spip->spd_txcnt = n;
+ SPI->ICR = SPI_ICR_TXEI | SPI_ICR_RXEI | SPI_ICR_ERRIE;
+}
+
+/**
+ * @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->spd_rxptr = rxbuf;
+ spip->spd_txptr = txbuf;
+ spip->spd_rxcnt = spip->spd_txcnt = n;
+ SPI->ICR = SPI_ICR_TXEI | SPI_ICR_RXEI | SPI_ICR_ERRIE;
+}
+
+/**
+ * @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->spd_rxptr = NULL;
+ spip->spd_txptr = txbuf;
+ spip->spd_rxcnt = spip->spd_txcnt = n;
+ SPI->ICR = SPI_ICR_TXEI | SPI_ICR_RXEI | SPI_ICR_ERRIE;
+}
+
+/**
+ * @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->spd_rxptr = rxbuf;
+ spip->spd_txptr = NULL;
+ spip->spd_rxcnt = spip->spd_txcnt = n;
+ SPI->ICR = SPI_ICR_TXEI | SPI_ICR_RXEI | SPI_ICR_ERRIE;
+}
+
+/**
+ * @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.
+ */
+uint8_t spi_lld_polled_exchange(SPIDriver *spip, uint8_t frame) {
+
+ (void)spip;
+
+ SPI->DR = (uint32_t)frame;
+ while ((SPI->SR & SPI_SR_RXNE) == 0)
+ ;
+ return (uint16_t)SPI->DR;
+}
+
+#endif /* HAL_USE_SPI */
+
+/** @} */
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