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/*
ChibiOS/RT - Copyright (C) 2006,2007,2008,2009,2010 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.h
* @brief SPI Driver macros and structures.
*
* @addtogroup SPI
* @{
*/
#ifndef _SPI_H_
#define _SPI_H_
#if CH_HAL_USE_SPI || defined(__DOXYGEN__)
/*===========================================================================*/
/* Driver constants. */
/*===========================================================================*/
/*===========================================================================*/
/* Driver pre-compile time settings. */
/*===========================================================================*/
/**
* @brief Enables the "wait" 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, /**< @brief Not initialized. */
SPI_STOP = 1, /**< @brief Stopped. */
SPI_READY = 2, /**< @brief Ready. */
SPI_SYNC= 3, /**< @brief Synchronizing. */
SPI_SELECTED = 4, /**< @brief Slave selected. */
SPI_ACTIVE = 5 /**< @brief Exchanging data. */
} 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
*
* @api
*/
#define spiSelectI(spip) { \
(spip)->spd_state = SPI_SELECTED; \
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
*
* @api
*/
#define spiUnselectI(spip) { \
(spip)->spd_state = SPI_READY; \
spi_lld_unselect(spip); \
}
/**
* @brief Emits a train of clock pulses on the SPI bus.
* @details This asynchronous function starts the emission of a train of
* clock pulses without asserting any slave.
* @note This functionality is not usually required by the SPI protocol
* but it is required by initialization procedure of MMC/SD cards
* in SPI mode.
* @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 clocked. The number of pulses
* is equal to the number of words multiplied to the
* configured word size in bits.
*
* @api
*/
#define spiSynchronizeI(spip, n) { \
(spip)->spd_state = SPI_SYNC; \
spi_lld_ignore(spip, n); \
}
/**
* @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
*
* @api
*/
#define spiIgnoreI(spip, n) { \
(spip)->spd_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
*
* @api
*/
#define spiExchangeI(spip, n, txbuf, rxbuf) { \
(spip)->spd_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
*
* @api
*/
#define spiSendI(spip, n, txbuf) { \
(spip)->spd_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
*
* @api
*/
#define spiReceiveI(spip, n, rxbuf) { \
(spip)->spd_state = SPI_ACTIVE; \
spi_lld_receive(spip, n, rxbuf); \
}
#if SPI_USE_WAIT || defined(__DOXYGEN__)
/**
* @brief Awakens the thread waiting for operation completion, if any.
* @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_wakeup(spip) { \
if ((spip)->spd_thread != NULL) { \
Thread *tp = (spip)->spd_thread; \
(spip)->spd_thread = NULL; \
tp->p_u.rdymsg = RDY_RESET; \
chSchReadyI(tp); \
} \
}
/**
* @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.
* @post On exit the SPI driver is ready to accept more commands.
* @note No more than one thread can wait on a SPI driver using
* this function.
*
* @param[in] spip pointer to the @p SPIDriver object
*
* @sclass
*/
#define spiWaitS(spip) { \
chDbgAssert((spip)->spd_thread == NULL, \
"spiWaitS(), #1", "already waiting"); \
(spip)->spd_thread = chThdSelf(); \
chSchGoSleepS(THD_STATE_SUSPENDED); \
}
#else /* !SPI_USE_WAIT */
/* No wakeup when wait functions are disabled.*/
#define _spi_wakeup(spip)
#endif /* !SPI_USE_WAIT */
/*===========================================================================*/
/* 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 spiSynchronize(SPIDriver *spip, size_t n);
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);
#if SPI_USE_WAIT
void spiWait(SPIDriver *spip);
void spiSynchronizeWait(SPIDriver *spip, size_t n);
void spiIgnoreWait(SPIDriver *spip, size_t n);
void spiExchangeWait(SPIDriver *spip, size_t n, const void *txbuf, void *rxbuf);
void spiSendWait(SPIDriver *spip, size_t n, const void *txbuf);
void spiReceiveWait(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 /* CH_HAL_USE_SPI */
#endif /* _SPI_H_ */
/** @} */
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