tinySA/os/hal/platforms/STM32/spi_lld.c

/*
    ChibiOS/RT - Copyright (C) 2006,2007,2008,2009,2010,
                 2011,2012 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    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 local definitions.                                                 */
/*===========================================================================*/

#define SPI1_RX_DMA_CHANNEL                                                 \
  STM32_DMA_GETCHANNEL(STM32_SPI_SPI1_RX_DMA_STREAM,                        \
                       STM32_SPI1_RX_DMA_CHN)

#define SPI1_TX_DMA_CHANNEL                                                 \
  STM32_DMA_GETCHANNEL(STM32_SPI_SPI1_TX_DMA_STREAM,                        \
                       STM32_SPI1_TX_DMA_CHN)

#define SPI2_RX_DMA_CHANNEL                                                 \
  STM32_DMA_GETCHANNEL(STM32_SPI_SPI2_RX_DMA_STREAM,                        \
                       STM32_SPI2_RX_DMA_CHN)

#define SPI2_TX_DMA_CHANNEL                                                 \
  STM32_DMA_GETCHANNEL(STM32_SPI_SPI2_TX_DMA_STREAM,                        \
                       STM32_SPI2_TX_DMA_CHN)

#define SPI3_RX_DMA_CHANNEL                                                 \
  STM32_DMA_GETCHANNEL(STM32_SPI_SPI3_RX_DMA_STREAM,                        \
                       STM32_SPI3_RX_DMA_CHN)

#define SPI3_TX_DMA_CHANNEL                                                 \
  STM32_DMA_GETCHANNEL(STM32_SPI_SPI3_TX_DMA_STREAM,                        \
                       STM32_SPI3_TX_DMA_CHN)

/*===========================================================================*/
/* 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   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 | STM32_DMA_ISR_DMEIF)) != 0) {
    STM32_SPI_DMA_ERROR_HOOK(spip);
  }
#else
  (void)flags;
#endif

  /* Stop everything.*/
  dmaStreamDisable(spip->dmatx);
  dmaStreamDisable(spip->dmarx);

  /* 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 | STM32_DMA_ISR_DMEIF)) != 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.spi       = SPI1;
  SPID1.dmarx     = STM32_DMA_STREAM(STM32_SPI_SPI1_RX_DMA_STREAM);
  SPID1.dmatx     = STM32_DMA_STREAM(STM32_SPI_SPI1_TX_DMA_STREAM);
  SPID1.rxdmamode = STM32_DMA_CR_CHSEL(SPI1_RX_DMA_CHANNEL) |
                    STM32_DMA_CR_PL(STM32_SPI_SPI1_DMA_PRIORITY) |
                    STM32_DMA_CR_DIR_P2M |
                    STM32_DMA_CR_TCIE |
                    STM32_DMA_CR_DMEIE |
                    STM32_DMA_CR_TEIE;
  SPID1.txdmamode = STM32_DMA_CR_CHSEL(SPI1_TX_DMA_CHANNEL) |
                    STM32_DMA_CR_PL(STM32_SPI_SPI1_DMA_PRIORITY) |
                    STM32_DMA_CR_DIR_M2P |
                    STM32_DMA_CR_DMEIE |
                    STM32_DMA_CR_TEIE;
#endif

#if STM32_SPI_USE_SPI2
  spiObjectInit(&SPID2);
  SPID2.spi       = SPI2;
  SPID2.dmarx     = STM32_DMA_STREAM(STM32_SPI_SPI2_RX_DMA_STREAM);
  SPID2.dmatx     = STM32_DMA_STREAM(STM32_SPI_SPI2_TX_DMA_STREAM);
  SPID2.rxdmamode = STM32_DMA_CR_CHSEL(SPI2_RX_DMA_CHANNEL) |
                    STM32_DMA_CR_PL(STM32_SPI_SPI2_DMA_PRIORITY) |
                    STM32_DMA_CR_DIR_P2M |
                    STM32_DMA_CR_TCIE |
                    STM32_DMA_CR_DMEIE |
                    STM32_DMA_CR_TEIE;
  SPID2.txdmamode = STM32_DMA_CR_CHSEL(SPI2_TX_DMA_CHANNEL) |
                    STM32_DMA_CR_PL(STM32_SPI_SPI2_DMA_PRIORITY) |
                    STM32_DMA_CR_DIR_M2P |
                    STM32_DMA_CR_DMEIE |
                    STM32_DMA_CR_TEIE;
#endif

#if STM32_SPI_USE_SPI3
  spiObjectInit(&SPID3);
  SPID3.spi       = SPI3;
  SPID3.dmarx     = STM32_DMA_STREAM(STM32_SPI_SPI3_RX_DMA_STREAM);
  SPID3.dmatx     = STM32_DMA_STREAM(STM32_SPI_SPI3_TX_DMA_STREAM);
  SPID3.rxdmamode = STM32_DMA_CR_CHSEL(SPI3_RX_DMA_CHANNEL) |
                    STM32_DMA_CR_PL(STM32_SPI_SPI3_DMA_PRIORITY) |
                    STM32_DMA_CR_DIR_P2M |
                    STM32_DMA_CR_TCIE |
                    STM32_DMA_CR_DMEIE |
                    STM32_DMA_CR_TEIE;
  SPID3.txdmamode = STM32_DMA_CR_CHSEL(SPI3_TX_DMA_CHANNEL) |
                    STM32_DMA_CR_PL(STM32_SPI_SPI3_DMA_PRIORITY) |
                    STM32_DMA_CR_DIR_M2P |
                    STM32_DMA_CR_DMEIE |
                    STM32_DMA_CR_TEIE;
#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(spip->dmarx,
                            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(spip->dmatx,
                            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(spip->dmarx,
                            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(spip->dmatx,
                            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(spip->dmarx,
                            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(spip->dmatx,
                            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);
  }

  /* Configuration-specific DMA setup.*/
  if ((spip->config->cr1 & SPI_CR1_DFF) == 0) {     /* 8 bits transfers.    */
    spip->rxdmamode = (spip->rxdmamode & ~STM32_DMA_CR_SIZE_MASK) |
                      STM32_DMA_CR_PSIZE_BYTE | STM32_DMA_CR_MSIZE_BYTE;
    spip->txdmamode = (spip->txdmamode & ~STM32_DMA_CR_SIZE_MASK) |
                      STM32_DMA_CR_PSIZE_BYTE | STM32_DMA_CR_MSIZE_BYTE;
  }
  else {                                            /* 16 bits transfers.   */
    spip->rxdmamode = (spip->rxdmamode & ~STM32_DMA_CR_SIZE_MASK) |
                      STM32_DMA_CR_PSIZE_HWORD | STM32_DMA_CR_MSIZE_HWORD;
    spip->txdmamode = (spip->txdmamode & ~STM32_DMA_CR_SIZE_MASK) |
                      STM32_DMA_CR_PSIZE_HWORD | STM32_DMA_CR_MSIZE_HWORD;
  }
  /* 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;
    dmaStreamRelease(spip->dmarx);
    dmaStreamRelease(spip->dmatx);

#if STM32_SPI_USE_SPI1
    if (&SPID1 == spip)
      rccDisableSPI1(FALSE);
#endif
#if STM32_SPI_USE_SPI2
    if (&SPID2 == spip)
      rccDisableSPI2(FALSE);
#endif
#if STM32_SPI_USE_SPI3
    if (&SPID3 == spip)
      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->rxdmamode | STM32_DMA_CR_EN);

  dmaStreamSetMemory0(spip->dmatx, &dummytx);
  dmaStreamSetTransactionSize(spip->dmatx, n);
  dmaStreamSetMode(spip->dmatx, spip->txdmamode | 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->rxdmamode| STM32_DMA_CR_MINC |
                                                 STM32_DMA_CR_EN);
  dmaStreamSetMemory0(spip->dmatx, txbuf);
  dmaStreamSetTransactionSize(spip->dmatx, n);
  dmaStreamSetMode(spip->dmatx, spip->txdmamode | 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->rxdmamode | STM32_DMA_CR_EN);

  dmaStreamSetMemory0(spip->dmatx, txbuf);
  dmaStreamSetTransactionSize(spip->dmatx, n);
  dmaStreamSetMode(spip->dmatx, spip->txdmamode | 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->rxdmamode | STM32_DMA_CR_MINC |
                                                  STM32_DMA_CR_EN);
  dmaStreamSetMemory0(spip->dmatx, &dummytx);
  dmaStreamSetTransactionSize(spip->dmatx, n);
  dmaStreamSetMode(spip->dmatx, spip->txdmamode | 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 */

/** @} */