/* ChibiOS/RT - Copyright (C) 2006,2007,2008,2009,2010, 2011 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 . */ /** * @file STM32/spi_lld.c * @brief STM32 SPI subsystem low level driver source. * * @addtogroup SPI * @{ */ #include "ch.h" #include "hal.h" #if HAL_USE_SPI || defined(__DOXYGEN__) /*===========================================================================*/ /* Driver exported variables. */ /*===========================================================================*/ /** @brief SPI1 driver identifier.*/ #if STM32_SPI_USE_SPI1 || defined(__DOXYGEN__) SPIDriver SPID1; #endif /** @brief SPI2 driver identifier.*/ #if STM32_SPI_USE_SPI2 || defined(__DOXYGEN__) SPIDriver SPID2; #endif /** @brief SPI3 driver identifier.*/ #if STM32_SPI_USE_SPI3 || defined(__DOXYGEN__) SPIDriver SPID3; #endif /*===========================================================================*/ /* Driver local variables. */ /*===========================================================================*/ static uint16_t dummytx; static uint16_t dummyrx; /*===========================================================================*/ /* Driver local functions. */ /*===========================================================================*/ /** * @brief Stops the SPI DMA channels. * * @param[in] spip pointer to the @p SPIDriver object */ #define dma_stop(spip) { \ dmaStreamDisable(spip->dmatx); \ dmaStreamDisable(spip->dmarx); \ } /** * @brief Starts the SPI DMA channels. * * @param[in] spip pointer to the @p SPIDriver object */ #define dma_start(spip) { \ dmaChannelEnable((spip)->dmarx); \ dmaChannelEnable((spip)->dmatx); \ } /** * @brief Shared end-of-rx service routine. * * @param[in] spip pointer to the @p SPIDriver object * @param[in] flags pre-shifted content of the ISR register */ static void spi_lld_serve_rx_interrupt(SPIDriver *spip, uint32_t flags) { /* DMA errors handling.*/ #if defined(STM32_SPI_DMA_ERROR_HOOK) if ((flags & STM32_DMA_ISR_TEIF) != 0) { STM32_SPI_DMA_ERROR_HOOK(spip); } #else (void)flags; #endif /* Stop everything.*/ dma_stop(spip); /* Portable SPI ISR code defined in the high level driver, note, it is a macro.*/ _spi_isr_code(spip); } /** * @brief Shared end-of-tx service routine. * * @param[in] spip pointer to the @p SPIDriver object * @param[in] flags pre-shifted content of the ISR register */ static void spi_lld_serve_tx_interrupt(SPIDriver *spip, uint32_t flags) { /* DMA errors handling.*/ #if defined(STM32_SPI_DMA_ERROR_HOOK) (void)spip; if ((flags & STM32_DMA_ISR_TEIF) != 0) { STM32_SPI_DMA_ERROR_HOOK(spip); } #else (void)spip; (void)flags; #endif } /*===========================================================================*/ /* Driver interrupt handlers. */ /*===========================================================================*/ /*===========================================================================*/ /* Driver exported functions. */ /*===========================================================================*/ /** * @brief Low level SPI driver initialization. * * @notapi */ void spi_lld_init(void) { dummytx = 0xFFFF; #if STM32_SPI_USE_SPI1 spiObjectInit(&SPID1); SPID1.thread = NULL; SPID1.spi = SPI1; SPID1.dmarx = STM32_DMA1_STREAM2; SPID1.dmatx = STM32_DMA1_STREAM3; #endif #if STM32_SPI_USE_SPI2 spiObjectInit(&SPID2); SPID2.thread = NULL; SPID2.spi = SPI2; SPID2.dmarx = STM32_DMA1_STREAM4; SPID2.dmatx = STM32_DMA1_STREAM5; #endif #if STM32_SPI_USE_SPI3 spiObjectInit(&SPID3); SPID3.thread = NULL; SPID3.spi = SPI3; SPID3.dmarx = STM32_DMA2_STREAM1; SPID3.dmatx = STM32_DMA2_STREAM2; #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 in stopped state then enables the SPI and DMA clocks.*/ if (spip->state == SPI_STOP) { #if STM32_SPI_USE_SPI1 if (&SPID1 == spip) { bool_t b; b = dmaStreamAllocate(STM32_DMA1_STREAM2, STM32_SPI_SPI1_IRQ_PRIORITY, (stm32_dmaisr_t)spi_lld_serve_rx_interrupt, (void *)spip); chDbgAssert(!b, "spi_lld_start(), #1", "stream already allocated"); b = dmaStreamAllocate(STM32_DMA1_STREAM3, STM32_SPI_SPI1_IRQ_PRIORITY, (stm32_dmaisr_t)spi_lld_serve_tx_interrupt, (void *)spip); chDbgAssert(!b, "spi_lld_start(), #2", "stream already allocated"); rccEnableSPI1(FALSE); } #endif #if STM32_SPI_USE_SPI2 if (&SPID2 == spip) { bool_t b; b = dmaStreamAllocate(STM32_DMA1_STREAM4, STM32_SPI_SPI2_IRQ_PRIORITY, (stm32_dmaisr_t)spi_lld_serve_rx_interrupt, (void *)spip); chDbgAssert(!b, "spi_lld_start(), #3", "stream already allocated"); b = dmaStreamAllocate(STM32_DMA1_STREAM5, STM32_SPI_SPI2_IRQ_PRIORITY, (stm32_dmaisr_t)spi_lld_serve_tx_interrupt, (void *)spip); chDbgAssert(!b, "spi_lld_start(), #4", "stream already allocated"); rccEnableSPI2(FALSE); } #endif #if STM32_SPI_USE_SPI3 if (&SPID3 == spip) { bool_t b; b = dmaStreamAllocate(STM32_DMA2_STREAM1, STM32_SPI_SPI3_IRQ_PRIORITY, (stm32_dmaisr_t)spi_lld_serve_rx_interrupt, (void *)spip); chDbgAssert(!b, "spi_lld_start(), #5", "stream already allocated"); b = dmaStreamAllocate(STM32_DMA2_STREAM2, STM32_SPI_SPI3_IRQ_PRIORITY, (stm32_dmaisr_t)spi_lld_serve_tx_interrupt, (void *)spip); chDbgAssert(!b, "spi_lld_start(), #6", "stream already allocated"); rccEnableSPI3(FALSE); } #endif /* DMA setup.*/ dmaStreamSetPeripheral(spip->dmarx, &spip->spi->DR); dmaStreamSetPeripheral(spip->dmatx, &spip->spi->DR); } /* More DMA setup.*/ if ((spip->config->cr1 & SPI_CR1_DFF) == 0) spip->dmamode = STM32_DMA_CR_PL(STM32_SPI_SPI2_DMA_PRIORITY) | STM32_DMA_CR_TEIE | STM32_DMA_CR_PSIZE_BYTE | STM32_DMA_CR_MSIZE_BYTE; /* 8 bits transfers. */ else spip->dmamode = STM32_DMA_CR_PL(STM32_SPI_SPI2_DMA_PRIORITY) | STM32_DMA_CR_TEIE | STM32_DMA_CR_PSIZE_HWORD | STM32_DMA_CR_MSIZE_HWORD; /* 16 bits transfers. */ /* SPI setup and enable.*/ spip->spi->CR1 = 0; spip->spi->CR1 = spip->config->cr1 | SPI_CR1_MSTR | SPI_CR1_SSM | SPI_CR1_SSI; spip->spi->CR2 = SPI_CR2_SSOE | SPI_CR2_RXDMAEN | SPI_CR2_TXDMAEN; spip->spi->CR1 |= SPI_CR1_SPE; } /** * @brief Deactivates the SPI peripheral. * * @param[in] spip pointer to the @p SPIDriver object * * @notapi */ void spi_lld_stop(SPIDriver *spip) { /* If in ready state then disables the SPI clock.*/ if (spip->state == SPI_READY) { /* SPI disable.*/ spip->spi->CR1 = 0; #if STM32_SPI_USE_SPI1 if (&SPID1 == spip) { dmaStreamRelease(STM32_DMA1_STREAM2); dmaStreamRelease(STM32_DMA1_STREAM3); rccDisableSPI1(FALSE); } #endif #if STM32_SPI_USE_SPI2 if (&SPID2 == spip) { dmaStreamRelease(STM32_DMA1_STREAM4); dmaStreamRelease(STM32_DMA1_STREAM5); rccDisableSPI2(FALSE); } #endif #if STM32_SPI_USE_SPI3 if (&SPID3 == spip) { dmaStreamRelease(STM32_DMA2_STREAM1); dmaStreamRelease(STM32_DMA2_STREAM2); rccDisableSPI3(FALSE); } #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 asynchronous function starts the transmission of a series of * idle words on the SPI bus and ignores the received data. * @post At the end of the operation the configured callback is invoked. * * @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) { dmaStreamSetMemory0(spip->dmarx, &dummyrx); dmaStreamSetTransactionSize(spip->dmarx, n); dmaStreamSetMode(spip->dmarx, spip->dmamode | STM32_DMA_CR_DIR_P2M | STM32_DMA_CR_TCIE | STM32_DMA_CR_EN); dmaStreamSetMemory0(spip->dmatx, &dummytx); dmaStreamSetTransactionSize(spip->dmatx, n); dmaStreamSetMode(spip->dmatx, spip->dmamode | STM32_DMA_CR_DIR_M2P | STM32_DMA_CR_EN); } /** * @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) { dmaStreamSetMemory0(spip->dmarx, rxbuf); dmaStreamSetTransactionSize(spip->dmarx, n); dmaStreamSetMode(spip->dmarx, spip->dmamode | STM32_DMA_CR_DIR_P2M | STM32_DMA_CR_TCIE | STM32_DMA_CR_MINC | STM32_DMA_CR_EN); dmaStreamSetMemory0(spip->dmatx, txbuf); dmaStreamSetTransactionSize(spip->dmatx, n); dmaStreamSetMode(spip->dmatx, spip->dmamode | STM32_DMA_CR_DIR_M2P | STM32_DMA_CR_MINC | STM32_DMA_CR_EN); } /** * @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) { dmaStreamSetMemory0(spip->dmarx, &dummyrx); dmaStreamSetTransactionSize(spip->dmarx, n); dmaStreamSetMode(spip->dmarx, spip->dmamode | STM32_DMA_CR_DIR_P2M | STM32_DMA_CR_TCIE | STM32_DMA_CR_EN); dmaStreamSetMemory0(spip->dmatx, txbuf); dmaStreamSetTransactionSize(spip->dmatx, n); dmaStreamSetMode(spip->dmatx, spip->dmamode | STM32_DMA_CR_DIR_M2P | STM32_DMA_CR_MINC | STM32_DMA_CR_EN); } /** * @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) { dmaStreamSetMemory0(spip->dmarx, rxbuf); dmaStreamSetTransactionSize(spip->dmarx, n); dmaStreamSetMode(spip->dmarx, spip->dmamode | STM32_DMA_CR_DIR_P2M | STM32_DMA_CR_TCIE | STM32_DMA_CR_MINC | STM32_DMA_CR_EN); dmaStreamSetMemory0(spip->dmatx, &dummytx); dmaStreamSetTransactionSize(spip->dmatx, n); dmaStreamSetMode(spip->dmatx, spip->dmamode | STM32_DMA_CR_DIR_M2P | STM32_DMA_CR_EN); } /** * @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->DR = frame; while ((spip->spi->SR & SPI_SR_RXNE) == 0) ; return spip->spi->DR; } #endif /* HAL_USE_SPI */ /** @} */