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/*
ChibiOS - Copyright (C) 2006..2015 Giovanni Di Sirio
Licensed under the Apache License, Version 2.0 (the "License");
you may not use this file except in compliance with the License.
You may obtain a copy of the License at
http://www.apache.org/licenses/LICENSE-2.0
Unless required by applicable law or agreed to in writing, software
distributed under the License is distributed on an "AS IS" BASIS,
WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
See the License for the specific language governing permissions and
limitations under the License.
*/
/*
Concepts and parts of this file have been contributed by Uladzimir Pylinsky
aka barthess.
*/
/**
* @file i2c.c
* @brief I2C Driver code.
*
* @addtogroup I2C
* @{
*/
#include "hal.h"
#if (HAL_USE_I2C == TRUE) || defined(__DOXYGEN__)
/*===========================================================================*/
/* Driver local definitions. */
/*===========================================================================*/
/*===========================================================================*/
/* Driver exported variables. */
/*===========================================================================*/
/*===========================================================================*/
/* Driver local variables and types. */
/*===========================================================================*/
/*===========================================================================*/
/* 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 == TRUE
osalMutexObjectInit(&i2cp->mutex);
#endif
#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) {
osalDbgCheck((i2cp != NULL) && (config != NULL));
osalDbgAssert((i2cp->state == I2C_STOP) || (i2cp->state == I2C_READY) ||
(i2cp->state == I2C_LOCKED), "invalid state");
osalSysLock();
i2cp->config = config;
i2c_lld_start(i2cp);
i2cp->state = I2C_READY;
osalSysUnlock();
}
/**
* @brief Deactivates the I2C peripheral.
*
* @param[in] i2cp pointer to the @p I2CDriver object
*
* @api
*/
void i2cStop(I2CDriver *i2cp) {
osalDbgCheck(i2cp != NULL);
osalDbgAssert((i2cp->state == I2C_STOP) || (i2cp->state == I2C_READY) ||
(i2cp->state == I2C_LOCKED), "invalid state");
osalSysLock();
i2c_lld_stop(i2cp);
i2cp->state = I2C_STOP;
osalSysUnlock();
}
/**
* @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) {
osalDbgCheck(i2cp != NULL);
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 MSG_OK if the function succeeded.
* @retval MSG_RESET if one or more I2C errors occurred, the errors can
* be retrieved using @p i2cGetErrors().
* @retval MSG_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;
osalDbgCheck((i2cp != NULL) && (addr != 0U) &&
(txbytes > 0U) && (txbuf != NULL) &&
((rxbytes == 0U) || ((rxbytes > 0U) && (rxbuf != NULL))) &&
(timeout != TIME_IMMEDIATE));
osalDbgAssert(i2cp->state == I2C_READY, "not ready");
osalSysLock();
i2cp->errors = I2C_NO_ERROR;
i2cp->state = I2C_ACTIVE_TX;
rdymsg = i2c_lld_master_transmit_timeout(i2cp, addr, txbuf, txbytes,
rxbuf, rxbytes, timeout);
if (rdymsg == MSG_TIMEOUT) {
i2cp->state = I2C_LOCKED;
}
else {
i2cp->state = I2C_READY;
}
osalSysUnlock();
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 MSG_OK if the function succeeded.
* @retval MSG_RESET if one or more I2C errors occurred, the errors can
* be retrieved using @p i2cGetErrors().
* @retval MSG_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;
osalDbgCheck((i2cp != NULL) && (addr != 0U) &&
(rxbytes > 0U) && (rxbuf != NULL) &&
(timeout != TIME_IMMEDIATE));
osalDbgAssert(i2cp->state == I2C_READY, "not ready");
osalSysLock();
i2cp->errors = I2C_NO_ERROR;
i2cp->state = I2C_ACTIVE_RX;
rdymsg = i2c_lld_master_receive_timeout(i2cp, addr, rxbuf, rxbytes, timeout);
if (rdymsg == MSG_TIMEOUT) {
i2cp->state = I2C_LOCKED;
}
else {
i2cp->state = I2C_READY;
}
osalSysUnlock();
return rdymsg;
}
#if (I2C_USE_MUTUAL_EXCLUSION == TRUE) || 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.
* @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) {
osalDbgCheck(i2cp != NULL);
osalMutexLock(&i2cp->mutex);
}
/**
* @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) {
osalDbgCheck(i2cp != NULL);
osalMutexUnlock(&i2cp->mutex);
}
#endif /* I2C_USE_MUTUAL_EXCLUSION == TRUE */
#endif /* HAL_USE_I2C == TRUE */
/** @} */
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