/* 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 spi.h * @brief SPI Driver macros and structures. * * @addtogroup SPI * @{ */ #ifndef _SPI_H_ #define _SPI_H_ #if HAL_USE_SPI || defined(__DOXYGEN__) /*===========================================================================*/ /* Driver constants. */ /*===========================================================================*/ /*===========================================================================*/ /* Driver pre-compile time settings. */ /*===========================================================================*/ /** * @brief Enables synchronous APIs. * @note Disabling this option saves both code and data space. */ #if !defined(SPI_USE_WAIT) || defined(__DOXYGEN__) #define SPI_USE_WAIT TRUE #endif /** * @brief Enables the @p spiAcquireBus() and @p spiReleaseBus() APIs. * @note Disabling this option saves both code and data space. */ #if !defined(SPI_USE_MUTUAL_EXCLUSION) || defined(__DOXYGEN__) #define SPI_USE_MUTUAL_EXCLUSION TRUE #endif /*===========================================================================*/ /* Derived constants and error checks. */ /*===========================================================================*/ #if SPI_USE_MUTUAL_EXCLUSION && !CH_USE_MUTEXES && !CH_USE_SEMAPHORES #error "SPI_USE_MUTUAL_EXCLUSION requires CH_USE_MUTEXES and/or CH_USE_SEMAPHORES" #endif /*===========================================================================*/ /* Driver data structures and types. */ /*===========================================================================*/ /** * @brief Driver state machine possible states. */ typedef enum { SPI_UNINIT = 0, /**< Not initialized. */ SPI_STOP = 1, /**< Stopped. */ SPI_READY = 2, /**< Ready. */ SPI_ACTIVE = 3, /**< Exchanging data. */ SPI_COMPLETE = 4 /**< Asynchronous operation complete. */ } spistate_t; #include "spi_lld.h" /*===========================================================================*/ /* Driver macros. */ /*===========================================================================*/ /** * @brief Asserts the slave select signal and prepares for transfers. * * @param[in] spip pointer to the @p SPIDriver object * * @iclass */ #define spiSelectI(spip) { \ spi_lld_select(spip); \ } /** * @brief Deasserts the slave select signal. * @details The previously selected peripheral is unselected. * * @param[in] spip pointer to the @p SPIDriver object * * @iclass */ #define spiUnselectI(spip) { \ spi_lld_unselect(spip); \ } /** * @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. * @pre A slave must have been selected using @p spiSelect() or * @p spiSelectI(). * @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 * * @iclass */ #define spiStartIgnoreI(spip, n) { \ (spip)->state = SPI_ACTIVE; \ spi_lld_ignore(spip, n); \ } /** * @brief Exchanges data on the SPI bus. * @details This asynchronous function starts a simultaneous transmit/receive * operation. * @pre A slave must have been selected using @p spiSelect() or * @p spiSelectI(). * @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 * * @iclass */ #define spiStartExchangeI(spip, n, txbuf, rxbuf) { \ (spip)->state = SPI_ACTIVE; \ spi_lld_exchange(spip, n, txbuf, rxbuf); \ } /** * @brief Sends data over the SPI bus. * @details This asynchronous function starts a transmit operation. * @pre A slave must have been selected using @p spiSelect() or * @p spiSelectI(). * @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 * * @iclass */ #define spiStartSendI(spip, n, txbuf) { \ (spip)->state = SPI_ACTIVE; \ spi_lld_send(spip, n, txbuf); \ } /** * @brief Receives data from the SPI bus. * @details This asynchronous function starts a receive operation. * @pre A slave must have been selected using @p spiSelect() or * @p spiSelectI(). * @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 * * @iclass */ #define spiStartReceiveI(spip, n, rxbuf) { \ (spip)->state = SPI_ACTIVE; \ spi_lld_receive(spip, n, rxbuf); \ } /** * @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. * @note This API is implemented as a macro in order to minimize latency. * * @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. */ #define spiPolledExchange(spip, frame) spi_lld_polled_exchange(spip, frame) #if SPI_USE_WAIT || defined(__DOXYGEN__) /** * @brief Waits for operation completion. * @details This function waits for the driver to complete the current * operation. * @pre An operation must be running while the function is invoked. * @note No more than one thread can wait on a SPI driver using * this function. * * @param[in] spip pointer to the @p SPIDriver object * * @notapi */ #define _spi_wait_s(spip) { \ chDbgAssert((spip)->thread == NULL, \ "_spi_wait(), #1", "already waiting"); \ (spip)->thread = chThdSelf(); \ chSchGoSleepS(THD_STATE_SUSPENDED); \ } /** * @brief Wakes up the waiting thread. * * @param[in] spip pointer to the @p SPIDriver object * * @notapi */ #define _spi_wakeup_isr(spip) { \ if ((spip)->thread != NULL) { \ Thread *tp = (spip)->thread; \ (spip)->thread = NULL; \ chSysLockFromIsr(); \ chSchReadyI(tp); \ chSysUnlockFromIsr(); \ } \ } #else /* !SPI_USE_WAIT */ #define _spi_wait_s(spip) #define _spi_wakeup_isr(spip) #endif /* !SPI_USE_WAIT */ /** * @brief Common ISR code. * @details This code handles the portable part of the ISR code: * - Callback invocation. * - Waiting thread wakeup, if any. * - Driver state transitions. * . * @note This macro is meant to be used in the low level drivers * implementation only. * * @param[in] spip pointer to the @p SPIDriver object * * @notapi */ #define _spi_isr_code(spip) { \ if ((spip)->config->end_cb) { \ (spip)->state = SPI_COMPLETE; \ (spip)->config->end_cb(spip); \ if ((spip)->state == SPI_COMPLETE) \ (spip)->state = SPI_READY; \ } \ _spi_wakeup_isr(spip); \ } /*===========================================================================*/ /* External declarations. */ /*===========================================================================*/ #ifdef __cplusplus extern "C" { #endif void spiInit(void); void spiObjectInit(SPIDriver *spip); void spiStart(SPIDriver *spip, const SPIConfig *config); void spiStop(SPIDriver *spip); void spiSelect(SPIDriver *spip); void spiUnselect(SPIDriver *spip); void spiStartIgnore(SPIDriver *spip, size_t n); void spiStartExchange(SPIDriver *spip, size_t n, const void *txbuf, void *rxbuf); void spiStartSend(SPIDriver *spip, size_t n, const void *txbuf); void spiStartReceive(SPIDriver *spip, size_t n, void *rxbuf); #if SPI_USE_WAIT void spiIgnore(SPIDriver *spip, size_t n); void spiExchange(SPIDriver *spip, size_t n, const void *txbuf, void *rxbuf); void spiSend(SPIDriver *spip, size_t n, const void *txbuf); void spiReceive(SPIDriver *spip, size_t n, void *rxbuf); #endif /* SPI_USE_WAIT */ #if SPI_USE_MUTUAL_EXCLUSION void spiAcquireBus(SPIDriver *spip); void spiReleaseBus(SPIDriver *spip); #endif /* SPI_USE_MUTUAL_EXCLUSION */ #ifdef __cplusplus } #endif #endif /* HAL_USE_SPI */ #endif /* _SPI_H_ */ /** @} */