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/*
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 <http://www.gnu.org/licenses/>.
*/
/**
* @file i2c.c
* @brief I2C Driver code.
*
* @addtogroup I2C
* @{
*/
#include "ch.h"
#include "hal.h"
#if HAL_USE_I2C || defined(__DOXYGEN__)
/*===========================================================================*/
/* Driver exported variables. */
/*===========================================================================*/
/*===========================================================================*/
/* Driver local variables. */
/*===========================================================================*/
/*===========================================================================*/
/* Driver local functions. */
/*===========================================================================*/
/*===========================================================================*/
/* Driver exported functions. */
/*===========================================================================*/
/**
* @brief I2C Driver initialization.
* @note This function is implicitly invoked by @p halInit(), there is
* no need to explicitly initialize the driver.
*
* @init
*/
void i2cInit(void) {
i2c_lld_init();
}
/**
* @brief Initializes the standard part of a @p I2CDriver structure.
*
* @param[out] i2cp pointer to the @p I2CDriver object
*
* @init
*/
void i2cObjectInit(I2CDriver *i2cp) {
i2cp->id_state = I2C_STOP;
i2cp->id_config = NULL;
i2cp->rxBuffp = NULL;
i2cp->txBuffp = NULL;
i2cp->id_slave_config = NULL;
#if I2C_USE_WAIT
i2cp->id_thread = NULL;
#endif /* I2C_USE_WAIT */
#if I2C_USE_MUTUAL_EXCLUSION
#if CH_USE_MUTEXES
chMtxInit(&i2cp->id_mutex);
#else
chSemInit(&i2cp->id_semaphore, 1);
#endif /* CH_USE_MUTEXES */
#endif /* I2C_USE_MUTUAL_EXCLUSION */
#if defined(I2C_DRIVER_EXT_INIT_HOOK)
I2C_DRIVER_EXT_INIT_HOOK(i2cp);
#endif
}
/**
* @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
*
* @api
*/
void i2cStart(I2CDriver *i2cp, const I2CConfig *config) {
chDbgCheck((i2cp != NULL) && (config != NULL), "i2cStart");
chSysLock();
chDbgAssert((i2cp->id_state == I2C_STOP) || (i2cp->id_state == I2C_READY),
"i2cStart(), #1",
"invalid state");
i2cp->id_config = config;
i2c_lld_start(i2cp);
i2cp->id_state = I2C_READY;
chSysUnlock();
}
/**
* @brief Deactivates the I2C peripheral.
*
* @param[in] i2cp pointer to the @p I2CDriver object
*
* @api
*/
void i2cStop(I2CDriver *i2cp) {
chDbgCheck(i2cp != NULL, "i2cStop");
chSysLock();
chDbgAssert((i2cp->id_state == I2C_STOP) || (i2cp->id_state == I2C_READY),
"i2cStop(), #1",
"invalid state");
i2c_lld_stop(i2cp);
i2cp->id_state = I2C_STOP;
chSysUnlock();
}
/**
* @brief Sends data ever the I2C bus.
*
* @param[in] i2cp pointer to the @p I2CDriver object
* @param[in] i2cscfg pointer to the @p I2C slave config
* @param[in] slave_addr Slave device address. Bits 0-9 contain slave
* device address. Bit 15 must be set to 1 if 10-bit
* addressing modes used. Otherwise keep it cleared.
* Bits 10-14 unused.
* @param[in] txbytes number of bytes to be transmited
* @param[in] rxbytes number of bytes to be received
*/
void i2cMasterTransmit(I2CDriver *i2cp, const I2CSlaveConfig *i2cscfg, uint16_t slave_addr, size_t txbytes, size_t rxbytes) {
chDbgCheck((i2cp != NULL) && (i2cscfg != NULL) &&\
(slave_addr != 0) &&\
(txbytes > 0) &&\
(i2cscfg->txbuf != NULL),
"i2cMasterTransmit");
/* init slave config field in driver */
i2cp->id_slave_config = i2cscfg;
#if I2C_USE_WAIT
i2c_lld_wait_bus_free(i2cp);
if(i2c_lld_bus_is_busy(i2cp)) {
#ifdef PRINTTRACE
print("I2C Bus busy!\n");
#endif
return;
};
#endif
chSysLock();
chDbgAssert(i2cp->id_state == I2C_READY,
"i2cMasterTransmit(), #1", "not ready");
i2cp->id_state = I2C_ACTIVE;
i2c_lld_master_transmit(i2cp, slave_addr, txbytes, rxbytes);
_i2c_wait_s(i2cp);
#if !I2C_USE_WAIT
i2c_lld_wait_bus_free(i2cp);
#endif
if (i2cp->id_state == I2C_COMPLETE)
i2cp->id_state = I2C_READY;
chSysUnlock();
}
/**
* @brief Receives data from the I2C bus.
*
* @param[in] i2cp pointer to the @p I2CDriver object
* @param[in] i2cscfg pointer to the @p I2C slave config
* @param[in] slave_addr Slave device address. Bits 0-9 contain slave
* device address. Bit 15 must be set to 1 if 10-bit
* addressing modes used. Otherwise keep it cleared.
* Bits 10-14 unused.
* @param[in] txbytes number of bytes to be transmited
*/
void i2cMasterReceive(I2CDriver *i2cp, const I2CSlaveConfig *i2cscfg, uint16_t slave_addr, size_t rxbytes){
chDbgCheck((i2cp != NULL) && (i2cscfg != NULL) &&\
(slave_addr != 0) &&\
(rxbytes > 0) && \
(i2cscfg->rxbuf != NULL),
"i2cMasterReceive");
/* init slave config field in driver */
i2cp->id_slave_config = i2cscfg;
#if I2C_USE_WAIT
i2c_lld_wait_bus_free(i2cp);
if(i2c_lld_bus_is_busy(i2cp)) {
#ifdef PRINTTRACE
print("I2C Bus busy!\n");
#endif
return;
};
#endif
chSysLock();
chDbgAssert(i2cp->id_state == I2C_READY,
"i2cMasterReceive(), #1", "not ready");
i2cp->id_state = I2C_ACTIVE;
i2c_lld_master_receive(i2cp, slave_addr, rxbytes);
_i2c_wait_s(i2cp);
#if !I2C_USE_WAIT
i2c_lld_wait_bus_free(i2cp);
#endif
if (i2cp->id_state == I2C_COMPLETE)
i2cp->id_state = I2C_READY;
chSysUnlock();
}
/* FIXME: I do not know what this function must do. And can not test it
uint16_t i2cSMBusAlertResponse(I2CDriver *i2cp, I2CSlaveConfig *i2cscfg) {
i2cMasterReceive(i2cp, i2cscfg);
return i2cp->id_slave_config->slave_addr;
}
*/
/**
* @brief Handles communication events/errors.
* @details Must be called from the I/O interrupt service routine in order to
* notify I/O conditions as errors, signals change etc.
*
* @param[in] i2cp pointer to a @p I2CDriver structure
* @param[in] mask condition flags to be added to the mask
*
* @iclass
*/
void i2cAddFlagsI(I2CDriver *i2cp, i2cflags_t mask) {
chDbgCheck(i2cp != NULL, "i2cAddFlagsI");
i2cp->errors |= mask;
chEvtBroadcastI(&i2cp->sevent);
}
/**
* @brief Returns and clears the errors mask associated to the driver.
*
* @param[in] i2cp pointer to a @p I2CDriver structure
* @return The condition flags modified since last time this
* function was invoked.
*
* @api
*/
i2cflags_t i2cGetAndClearFlags(I2CDriver *i2cp) {
i2cflags_t mask;
chDbgCheck(i2cp != NULL, "i2cGetAndClearFlags");
chSysLock();
mask = i2cp->errors;
i2cp->errors = I2CD_NO_ERROR;
chSysUnlock();
return mask;
}
#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.
*
* @param[in] i2cp pointer to the @p I2CDriver object
*
* @note This function is only available when the @p I2C_USE_MUTUAL_EXCLUSION
* option is set to @p TRUE.
*/
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.
*
* @param[in] i2cp pointer to the @p I2CDriver object
*
* @note This function is only available when the @p I2C_USE_MUTUAL_EXCLUSION
* option is set to @p TRUE.
*/
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 /* HAL_USE_I2C */
/** @} */
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