/* ChibiOS/RT - Copyright (C) 2006,2007,2008,2009,2010, 2011,2012 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 . --- A special exception to the GPL can be applied should you wish to distribute a combined work that includes ChibiOS/RT, without being obliged to provide the source code for any proprietary components. See the file exception.txt for full details of how and when the exception can be applied. */ /* Concepts and parts of this file have been contributed by Uladzimir Pylinsky aka barthess. */ /** * @file i2c.c * @brief I2C Driver code. * * @addtogroup I2C * @{ */ #include "ch.h" #include "hal.h" #if HAL_USE_I2C || defined(__DOXYGEN__) /*===========================================================================*/ /* Driver local definitions. */ /*===========================================================================*/ /*===========================================================================*/ /* 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->state = I2C_STOP; i2cp->config = NULL; #if I2C_USE_MUTUAL_EXCLUSION #if CH_USE_MUTEXES chMtxInit(&i2cp->mutex); #else chSemInit(&i2cp->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"); chDbgAssert((i2cp->state == I2C_STOP) || (i2cp->state == I2C_READY) || (i2cp->state == I2C_LOCKED), "i2cStart(), #1", "invalid state"); chSysLock(); i2cp->config = config; i2c_lld_start(i2cp); i2cp->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"); chDbgAssert((i2cp->state == I2C_STOP) || (i2cp->state == I2C_READY) || (i2cp->state == I2C_LOCKED), "i2cStop(), #1", "invalid state"); chSysLock(); i2c_lld_stop(i2cp); i2cp->state = I2C_STOP; chSysUnlock(); } /** * @brief Returns the errors mask associated to the previous operation. * * @param[in] i2cp pointer to the @p I2CDriver object * @return The errors mask. * * @api */ i2cflags_t i2cGetErrors(I2CDriver *i2cp) { chDbgCheck(i2cp != NULL, "i2cGetErrors"); return i2c_lld_get_errors(i2cp); } /** * @brief Sends data via the I2C bus. * @details Function designed to realize "read-through-write" transfer * paradigm. If you want transmit data without any further read, * than set @b rxbytes field to 0. * * @param[in] i2cp pointer to the @p I2CDriver object * @param[in] addr slave device address (7 bits) without R/W bit * @param[in] txbuf pointer to transmit buffer * @param[in] txbytes number of bytes to be transmitted * @param[out] rxbuf pointer to receive buffer * @param[in] rxbytes number of bytes to be received, set it to 0 if * you want transmit only * @param[in] timeout the number of ticks before the operation timeouts, * the following special values are allowed: * - @a TIME_INFINITE no timeout. * . * * @return The operation status. * @retval RDY_OK if the function succeeded. * @retval RDY_RESET if one or more I2C errors occurred, the errors can * be retrieved using @p i2cGetErrors(). * @retval RDY_TIMEOUT if a timeout occurred before operation end. * * @api */ msg_t i2cMasterTransmitTimeout(I2CDriver *i2cp, i2caddr_t addr, const uint8_t *txbuf, size_t txbytes, uint8_t *rxbuf, size_t rxbytes, systime_t timeout) { msg_t rdymsg; chDbgCheck((i2cp != NULL) && (addr != 0) && (txbytes > 0) && (txbuf != NULL) && ((rxbytes == 0) || ((rxbytes > 0) && (rxbuf != NULL))) && (timeout != TIME_IMMEDIATE), "i2cMasterTransmitTimeout"); chDbgAssert(i2cp->state == I2C_READY, "i2cMasterTransmitTimeout(), #1", "not ready"); chSysLock(); i2cp->errors = I2CD_NO_ERROR; i2cp->state = I2C_ACTIVE_TX; rdymsg = i2c_lld_master_transmit_timeout(i2cp, addr, txbuf, txbytes, rxbuf, rxbytes, timeout); if (rdymsg == RDY_TIMEOUT) i2cp->state = I2C_LOCKED; else i2cp->state = I2C_READY; chSysUnlock(); return rdymsg; } /** * @brief Receives data from the I2C bus. * * @param[in] i2cp pointer to the @p I2CDriver object * @param[in] addr slave device address (7 bits) without R/W bit * @param[out] rxbuf pointer to receive buffer * @param[in] rxbytes number of bytes to be received * @param[in] timeout the number of ticks before the operation timeouts, * the following special values are allowed: * - @a TIME_INFINITE no timeout. * . * * @return The operation status. * @retval RDY_OK if the function succeeded. * @retval RDY_RESET if one or more I2C errors occurred, the errors can * be retrieved using @p i2cGetErrors(). * @retval RDY_TIMEOUT if a timeout occurred before operation end. * * @api */ msg_t i2cMasterReceiveTimeout(I2CDriver *i2cp, i2caddr_t addr, uint8_t *rxbuf, size_t rxbytes, systime_t timeout){ msg_t rdymsg; chDbgCheck((i2cp != NULL) && (addr != 0) && (rxbytes > 0) && (rxbuf != NULL) && (timeout != TIME_IMMEDIATE), "i2cMasterReceiveTimeout"); chDbgAssert(i2cp->state == I2C_READY, "i2cMasterReceive(), #1", "not ready"); chSysLock(); i2cp->errors = I2CD_NO_ERROR; i2cp->state = I2C_ACTIVE_RX; rdymsg = i2c_lld_master_receive_timeout(i2cp, addr, rxbuf, rxbytes, timeout); if (rdymsg == RDY_TIMEOUT) i2cp->state = I2C_LOCKED; else i2cp->state = I2C_READY; chSysUnlock(); return rdymsg; } #if I2C_USE_MUTUAL_EXCLUSION || defined(__DOXYGEN__) /** * @brief Gains exclusive access to the I2C 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. * @pre In order to use this function the option @p I2C_USE_MUTUAL_EXCLUSION * must be enabled. * * @param[in] i2cp pointer to the @p I2CDriver object * * @api */ void i2cAcquireBus(I2CDriver *i2cp) { chDbgCheck(i2cp != NULL, "i2cAcquireBus"); #if CH_USE_MUTEXES chMtxLock(&i2cp->mutex); #elif CH_USE_SEMAPHORES chSemWait(&i2cp->semaphore); #endif } /** * @brief Releases exclusive access to the I2C bus. * @pre In order to use this function the option @p I2C_USE_MUTUAL_EXCLUSION * must be enabled. * * @param[in] i2cp pointer to the @p I2CDriver object * * @api */ void i2cReleaseBus(I2CDriver *i2cp) { chDbgCheck(i2cp != NULL, "i2cReleaseBus"); #if CH_USE_MUTEXES chMtxUnlock(); #elif CH_USE_SEMAPHORES chSemSignal(&i2cp->semaphore); #endif } #endif /* I2C_USE_MUTUAL_EXCLUSION */ #endif /* HAL_USE_I2C */ /** @} */