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/*
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 spi.c
* @brief SPI Driver code.
* @addtogroup SPI
* @{
*/
#include "ch.h"
#include "hal.h"
#if CH_HAL_USE_SPI || defined(__DOXYGEN__)
/**
* @brief SPI Driver initialization.
*/
void spiInit(void) {
spi_lld_init();
}
/**
* @brief Initializes the standard part of a @p SPIDriver structure.
*
* @param[in] spip pointer to the @p SPIDriver object
*/
void spiObjectInit(SPIDriver *spip) {
spip->spd_state = SPI_STOP;
#if CH_USE_MUTEXES
chMtxInit(&spip->spd_mutex);
#elif CH_USE_SEMAPHORES
chSemInit(&spip->spd_semaphore, 1);
#endif
spip->spd_config = NULL;
}
/**
* @brief Configures and activates the SPI peripheral.
*
* @param[in] spip pointer to the @p SPIDriver object
* @param[in] config pointer to the @p SPIConfig object
*/
void spiStart(SPIDriver *spip, const SPIConfig *config) {
chDbgCheck((spip != NULL) && (config != NULL), "spiStart");
chSysLock();
chDbgAssert((spip->spd_state == SPI_STOP) || (spip->spd_state == SPI_READY),
"spiStart(), #1",
"invalid state");
spip->spd_config = config;
spi_lld_start(spip);
spip->spd_state = SPI_READY;
chSysUnlock();
}
/**
* @brief Deactivates the SPI peripheral.
*
* @param[in] spip pointer to the @p SPIDriver object
*/
void spiStop(SPIDriver *spip) {
chDbgCheck(spip != NULL, "spiStop");
chSysLock();
chDbgAssert((spip->spd_state == SPI_STOP) || (spip->spd_state == SPI_READY),
"spiStop(), #1",
"invalid state");
spi_lld_stop(spip);
spip->spd_state = SPI_STOP;
chSysUnlock();
}
/**
* @brief Asserts the slave select signal and prepares for transfers.
*
* @param[in] spip pointer to the @p SPIDriver object
*/
void spiSelect(SPIDriver *spip) {
chDbgCheck(spip != NULL, "spiSelect");
chSysLock();
chDbgAssert((spip->spd_state == SPI_READY) ||
(spip->spd_state == SPI_ACTIVE),
"spiSelect(), #1",
"not idle");
spi_lld_select(spip);
spip->spd_state = SPI_ACTIVE;
chSysUnlock();
}
/**
* @brief Deasserts the slave select signal.
* @details The previously selected peripheral is unselected.
*
* @param[in] spip pointer to the @p SPIDriver object
*/
void spiUnselect(SPIDriver *spip) {
chDbgCheck(spip != NULL, "spiUnselect");
chSysLock();
chDbgAssert((spip->spd_state == SPI_READY) ||
(spip->spd_state == SPI_ACTIVE),
"spiUnselect(), #1",
"not locked");
spi_lld_unselect(spip);
spip->spd_state = SPI_READY;
chSysUnlock();
}
/**
* @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
*/
void spiIgnore(SPIDriver *spip, size_t n) {
chDbgCheck((spip != NULL) && (n > 0), "spiIgnore");
chDbgAssert((spip->spd_state == SPI_READY) || (spip->spd_state == SPI_ACTIVE),
"spiIgnore(), #1",
"not active");
spi_lld_ignore(spip, n);
}
/**
* @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[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
*
* @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.
*/
void spiExchange(SPIDriver *spip, size_t n, const void *txbuf, void *rxbuf) {
chDbgCheck((spip != NULL) && (n > 0) && (rxbuf != NULL) && (txbuf != NULL),
"spiExchange");
chDbgAssert(spip->spd_state == SPI_ACTIVE,
"spiExchange(), #1",
"not active");
spi_lld_exchange(spip, n, txbuf, rxbuf);
}
/**
* @brief Sends data ever the SPI bus.
*
* @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
*
* @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.
*/
void spiSend(SPIDriver *spip, size_t n, const void *txbuf) {
chDbgCheck((spip != NULL) && (n > 0) && (txbuf != NULL),
"spiSend");
chDbgAssert(spip->spd_state == SPI_ACTIVE,
"spiSend(), #1",
"not active");
spi_lld_send(spip, n, txbuf);
}
/**
* @brief Receives data from the SPI bus.
*
* @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
*
* @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.
*/
void spiReceive(SPIDriver *spip, size_t n, void *rxbuf) {
chDbgCheck((spip != NULL) && (n > 0) && (rxbuf != NULL),
"spiReceive");
chDbgAssert(spip->spd_state == SPI_ACTIVE,
"spiReceive(), #1",
"not active");
spi_lld_receive(spip, n, rxbuf);
}
#if SPI_USE_MUTUAL_EXCLUSION || defined(__DOXYGEN__)
/**
* @brief Gains exclusive access to the SPI bus.
* @details This function tries to gain ownership to the SPI bus, if the bus
* is already being used then the invoking thread is queued.
*
* @param[in] spip pointer to the @p SPIDriver object
*
* @note This function is only available when the @p SPI_USE_MUTUAL_EXCLUSION
* option is set to @p TRUE.
*/
void spiAcquireBus(SPIDriver *spip) {
chDbgCheck(spip != NULL, "spiAcquireBus");
#if CH_USE_MUTEXES
chMtxLock(&spip->spd_mutex);
#elif CH_USE_SEMAPHORES
chSemWait(&spip->spd_semaphore);
#endif
}
/**
* @brief Releases exclusive access to the SPI bus.
*
* @param[in] spip pointer to the @p SPIDriver object
*
* @note This function is only available when the @p SPI_USE_MUTUAL_EXCLUSION
* option is set to @p TRUE.
*/
void spiReleaseBus(SPIDriver *spip) {
chDbgCheck(spip != NULL, "spiReleaseBus");
#if CH_USE_MUTEXES
(void)spip;
chMtxUnlock();
#elif CH_USE_SEMAPHORES
chSemSignal(&spip->spd_semaphore);
#endif
}
#endif /*SPI_USE_MUTUAL_EXCLUSION */
#endif /* CH_HAL_USE_SPI */
/** @} */
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