ChibiOS/os/io/platforms/STM32/spi_lld.c

161 lines
4.9 KiB
C

/*
ChibiOS/RT - Copyright (C) 2006-2007 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 templates/spi_lld.c
* @brief SPI Driver subsystem low level driver source template
* @addtogroup SPI_LLD
* @{
*/
#include <ch.h>
#include <spi.h>
#include "nvic.h"
#include "board.h"
#if USE_STM32_SPI1 || defined(__DOXYGEN__)
/** @brief SPI1 driver identifier.*/
SPIDriver SPID1;
#endif
#if USE_STM32_SPI2 || defined(__DOXYGEN__)
/** @brief SPI2 driver identifier.*/
SPIDriver SPID2;
#endif
/*===========================================================================*/
/* Low Level Driver local functions. */
/*===========================================================================*/
/*===========================================================================*/
/* Low Level Driver interrupt handlers. */
/*===========================================================================*/
#if USE_STM32_SPI1 || defined(__DOXYGEN__)
CH_IRQ_HANDLER(Vector70) {
CH_IRQ_PROLOGUE();
CH_IRQ_EPILOGUE();
}
#endif
#if USE_STM32_SPI2 || defined(__DOXYGEN__)
CH_IRQ_HANDLER(Vector78) {
CH_IRQ_PROLOGUE();
CH_IRQ_EPILOGUE();
}
#endif
/*===========================================================================*/
/* Low Level Driver exported functions. */
/*===========================================================================*/
/**
* @brief Low level SPI driver initialization.
*/
void spi_lld_init(void) {
#if USE_STM32_SPI1
spiObjectInit(&SPID1);
SPID1.spd_spi = SPI1;
SPID1.spd_dmarx = DMA1_Channel2;
SPID1.spd_dmatx = DMA1_Channel3;
SPID1.spd_dmaprio = SPI1_DMA_PRIORITY << 12;
RCC->APB2ENR |= RCC_APB2ENR_SPI1EN;
GPIOA->CRH = (GPIOA->CRH & 0x000FFFFF) | 0xB4B00000;
#endif
#if USE_STM32_SPI2
spiObjectInit(&SPID2);
SPID2.spd_spi = SPI2;
SPID2.spd_dmarx = DMA1_Channel4;
SPID2.spd_dmatx = DMA1_Channel5;
SPID2.spd_dmaprio = SPI2_DMA_PRIORITY << 12;
RCC->APB1ENR |= RCC_APB1ENR_SPI2EN;
GPIOB->CRL = (GPIOB->CRL & 0x000FFFFF) | 0xB4B00000;
#endif
}
/**
* @brief Low level SPI bus setup.
*
* @param[in] spip pointer to the @p SPIDriver object
*/
void spi_lld_setup(SPIDriver *spip) {
spip->spd_spi->CR1 = spip->spd_config->spc_cr1;
}
/**
* @brief Asserts the slave select signal and prepares for transfers.
*
* @param[in] spip pointer to the @p SPIDriver object
*/
void spi_lld_select(SPIDriver *spip) {
palClearPad(spip->spd_config->spc_ssport, spip->spd_config->spc_sspad);
}
/**
* @brief De-asserts the slave select signal.
* @details The previously selected peripheral is unselected.
*
* @param[in] spip pointer to the @p SPIDriver object
*/
void spi_lld_unselect(SPIDriver *spip) {
palSetPad(spip->spd_config->spc_ssport, spip->spd_config->spc_sspad);
}
/**
* @brief Exchanges data on the SPI bus.
* @details This function performs a simultaneous transmit/receive operation.
*
* @param[in] spip pointer to the @p SPIDriver object
* @param n number of words to be exchanged
* @param rxbuf the pointer to the receive buffer, if @p NULL is specified then
* the input data is discarded.
* Note that the buffer is organized as an uint8_t array for
* data sizes below or equal to 8 bits else it is organized as
* an uint16_t array.
* @param txbuf the pointer to the transmit buffer, if @p NULL is specified all
* ones are transmitted.
* Note that the buffer is organized as an uint8_t array for
* data sizes below or equal to 8 bits else it is organized as
* an uint16_t array.
*/
void spi_lld_exchange(SPIDriver *spip, size_t n, void *rxbuf, void *txbuf) {
/*
* DMA setup.
*/
spip->spd_dmarx->CNDTR = (uint32_t)n;
spip->spd_dmarx->CPAR = (uint32_t)&spip->spd_spi->DR;
spip->spd_dmarx->CMAR = (uint32_t)rxbuf;
spip->spd_dmarx->CCR = spip->spd_dmaprio |
DMA_CCR1_MSIZE_0 | DMA_CCR1_MSIZE_0 |
DMA_CCR1_MINC | DMA_CCR1_TEIE | DMA_CCR1_TCIE;
}
/** @} */