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/*
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 <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 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 */
/** @} */
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