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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 i2c.c
* @brief I2C Driver code.
*
* @addtogroup I2C
* @{
*/
#include "ch.h"
#include "hal.h"
#if CH_HAL_USE_I2C || defined(__DOXYGEN__)
/*===========================================================================*/
/* Driver exported variables. */
/*===========================================================================*/
/*===========================================================================*/
/* Driver local variables. */
/*===========================================================================*/
/*===========================================================================*/
/* Driver local functions. */
/*===========================================================================*/
/*===========================================================================*/
/* Driver exported functions. */
/*===========================================================================*/
/**
* @brief I2C Driver initialization.
*/
void i2cInit(void) {
i2c_lld_init();
}
/**
* @brief Initializes the standard part of a @p I2CDriver structure.
*
* @param[in] i2cp pointer to the @p I2CDriver object
*/
void i2cObjectInit(I2CDriver *i2cp) {
i2cp->i2c_state = I2C_STOP;
i2cp->i2c_config = NULL;
}
/**
* @brief Configures and activates the I2C peripheral.
*
* @param[in] i2cp pointer to the @p I2CDriver object
* @param[in] config pointer to the @p I2CConfig object
*/
void i2cStart(I2CDriver *i2cp, const I2CConfig *config) {
chDbgCheck((i2cp != NULL) && (config != NULL), "i2cStart");
chSysLock();
chDbgAssert((i2cp->i2c_state == I2C_STOP) || (i2cp->i2c_state == I2C_READY),
"i2cStart(), #1",
"invalid state");
i2cp->i2c_config = config;
i2c_lld_start(i2cp);
i2cp->i2c_state = I2C_READY;
chSysUnlock();
}
/**
* @brief Deactivates the I2C peripheral.
*
* @param[in] i2cp pointer to the @p I2CDriver object
*/
void i2cStop(I2CDriver *i2cp) {
chDbgCheck(i2cp != NULL, "i2cStop");
chSysLock();
chDbgAssert((i2cp->i2c_state == I2C_STOP) || (i2cp->i2c_state == I2C_READY),
"i2cStop(), #1",
"invalid state");
i2c_lld_stop(i2cp);
i2cp->i2c_state = I2C_STOP;
chSysUnlock();
}
/**
* @brief Initiates a master bus transaction.
* @details This function sends a start bit followed by an one or two bytes
* header.
*
* @param[in] i2cp pointer to the @p I2CDriver object
* @param[in] header transaction header
* @param[in] callback operation complete callback
*/
void i2cMasterStartI(I2CDriver *i2cp,
uint16_t header,
i2ccallback_t callback) {
chDbgCheck((i2cp != NULL) && (callback != NULL), "i2cMasterStartI");
chDbgAssert(i2cp->i2c_state == I2C_READY,
"i2cMasterStartI(), #1", "invalid state");
i2cp->id_callback = callback;
i2c_lld_master_start(i2cp, header);
}
/**
* @brief Terminates a master bus transaction.
*
* @param[in] i2cp pointer to the @p I2CDriver object
* @param[in] callback operation complete callback
*/
void i2cMasterStopI(I2CDriver *i2cp, i2ccallback_t callback) {
chDbgCheck((i2cp != NULL) && (callback != NULL), "i2cMasterStopI");
chDbgAssert(i2cp->i2c_state == I2C_MREADY,
"i2cMasterStopI(), #1", "invalid state");
i2cp->id_callback = callback;
i2c_lld_master_stop(i2cp);
}
/**
* @brief Sends a restart bit.
* @details Restart bits are required by some types of I2C transactions.
*
* @param[in] i2cp pointer to the @p I2CDriver object
* @param[in] callback operation complete callback
*/
void i2cMasterRestartI(I2CDriver *i2cp, i2ccallback_t callback) {
chDbgCheck((i2cp != NULL) && (callback != NULL), "i2cMasterRestartI");
chDbgAssert(i2cp->i2c_state == I2C_MREADY,
"i2cMasterRestartI(), #1", "invalid state");
i2cp->id_callback = callback;
i2c_lld_master_restart(i2cp);
}
/**
* @brief Master transmission.
*
* @param[in] i2cp pointer to the @p I2CDriver object
* @param[in] n number of bytes to be transmitted
* @param[in] txbuf transmit data buffer pointer
* @param[in] callback operation complete callback
*/
void i2cMasterTransmitI(I2CDriver *i2cp, size_t n, const uint8_t *txbuf,
i2ccallback_t callback) {
chDbgCheck((i2cp != NULL) && (n > 0) &&
(txbuf != NULL) && (callback != NULL), "i2cMasterTransmitI");
chDbgAssert(i2cp->i2c_state == I2C_MREADY,
"i2cMasterTransmitI(), #1", "invalid state");
i2cp->id_callback = callback;
i2c_lld_master_transmit(i2cp, n, txbuf);
}
/**
* @brief Master receive.
*
* @param[in] i2cp pointer to the @p I2CDriver object
* @param[in] n number of bytes to be transmitted
* @param[in] rxbuf receive data buffer pointer
* @param[in] callback operation complete callback
*/
void i2cMasterReceiveI(I2CDriver *i2cp, size_t n, uint8_t *rxbuf,
i2ccallback_t callback) {
chDbgCheck((i2cp != NULL) && (n > 0) &&
(rxbuf != NULL) && (callback != NULL), "i2cMasterReceiveI");
chDbgAssert(i2cp->i2c_state == I2C_MREADY,
"i2cMasterReceiveI(), #1", "invalid state");
i2cp->id_callback = callback;
i2c_lld_master_receive(i2cp, n, rxbuf);
}
#if I2C_USE_MUTUAL_EXCLUSION || defined(__DOXYGEN__)
/**
* @brief Gains exclusive access to the I2C bus.
* @details This function tries to gain ownership to the I2C bus, if the bus
* is already being used then the invoking thread is queued.
* @note This function is only available when the @p I2C_USE_MUTUAL_EXCLUSION
* option is set to @p TRUE.
*
* @param[in] i2cp pointer to the @p I2CDriver object
*
*/
void i2cAcquireBus(I2CDriver *i2cp) {
chDbgCheck(i2cp != NULL, "i2cAcquireBus");
#if CH_USE_MUTEXES
chMtxLock(&i2cp->id_mutex);
#elif CH_USE_SEMAPHORES
chSemWait(&i2cp->id_semaphore);
#endif
}
/**
* @brief Releases exclusive access to the I2C bus.
* @note This function is only available when the @p I2C_USE_MUTUAL_EXCLUSION
* option is set to @p TRUE.
*
* @param[in] i2cp pointer to the @p I2CDriver object
*/
void i2cReleaseBus(I2CDriver *i2cp) {
chDbgCheck(i2cp != NULL, "i2cReleaseBus");
#if CH_USE_MUTEXES
(void)i2cp;
chMtxUnlock();
#elif CH_USE_SEMAPHORES
chSemSignal(&i2cp->id_semaphore);
#endif
}
#endif /* I2C_USE_MUTUAL_EXCLUSION */
#endif /* CH_HAL_USE_I2C */
/** @} */
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