ChibiOS/os/hal/include/i2c.h

/*
    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.h
 * @brief   I2C Driver macros and structures.
 *
 * @addtogroup I2C
 * @{
 */

#ifndef _I2C_H_
#define _I2C_H_

#if HAL_USE_I2C || defined(__DOXYGEN__)

/*===========================================================================*/
/* Driver constants.                                                         */
/*===========================================================================*/

/*===========================================================================*/
/* Driver constants.                                                         */
/*===========================================================================*/

/**
 * @name    I2C bus error conditions
 * @{
 */
#define I2CD_NO_ERROR               0x00   /**< @brief No error.            */
#define I2CD_BUS_ERROR              0x01   /**< @brief Bus Error.           */
#define I2CD_ARBITRATION_LOST       0x02   /**< @brief Arbitration Lost
                                                (master mode).              */
#define I2CD_ACK_FAILURE            0x04   /**< @brief Acknowledge Failure. */
#define I2CD_OVERRUN                0x08   /**< @brief Overrun/Underrun.    */
#define I2CD_PEC_ERROR              0x10   /**< @brief PEC Error in
                                                reception.                  */
#define I2CD_TIMEOUT                0x20   /**< @brief Timeout Error.       */
#define I2CD_SMB_ALERT              0x40   /**< @brief SMBus Alert.         */
/** @} */

/*===========================================================================*/
/* Driver pre-compile time settings.                                         */
/*===========================================================================*/

/**
 * @brief   Enables the mutual exclusion APIs on the I2C bus.
 */
#if !defined(I2C_USE_MUTUAL_EXCLUSION) || defined(__DOXYGEN__)
#define I2C_USE_MUTUAL_EXCLUSION    TRUE
#endif

/*===========================================================================*/
/* Derived constants and error checks.                                       */
/*===========================================================================*/

#if I2C_USE_MUTUAL_EXCLUSION && !CH_USE_MUTEXES && !CH_USE_SEMAPHORES
#error "I2C_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 {
  I2C_UNINIT = 0,                           /**< Not initialized.           */
  I2C_STOP = 1,                             /**< Stopped.                   */
  I2C_READY = 2,                            /**< Ready.                     */
  I2C_ACTIVE_TRANSMIT = 3,                  /**< Transmitting.              */
  I2C_ACTIVE_RECEIVE = 4,                   /**< Receiving.                 */
} i2cstate_t;

#include "i2c_lld.h"


/*===========================================================================*/
/* Driver macros.                                                            */
/*===========================================================================*/

/**
 * @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.
 * @note    No more than one thread can wait on a I2C driver using
 *          this function.
 *
 * @param[in] i2cp      pointer to the @p I2CDriver object
 *
 * @notapi
 */
#define _i2c_wait_s(i2cp) {                                                 \
  chDbgAssert((i2cp)->id_thread == NULL,                                    \
              "_i2c_wait(), #1", "already waiting");                        \
  chSysLock();                                                              \
  (i2cp)->id_thread = chThdSelf();                                          \
  chSchGoSleepS(THD_STATE_SUSPENDED);                                       \
  chSysUnlock();                                                            \
}

/**
 * @brief   Wakes up the waiting thread.
 *
 * @param[in] i2cp      pointer to the @p I2CDriver object
 *
 * @notapi
 */
#define _i2c_wakeup_isr(i2cp) {                                             \
  if ((i2cp)->id_thread != NULL) {                                          \
    Thread *tp = (i2cp)->id_thread;                                         \
    (i2cp)->id_thread = NULL;                                               \
    chSysLockFromIsr();                                                     \
    chSchReadyI(tp);                                                        \
    chSysUnlockFromIsr();                                                   \
  }                                                                         \
}

/**
 * @brief   Common ISR code.
 * @details This code handles the portable part of the ISR code:
 *          - Waiting thread wakeup.
 *          - Driver state transitions.
 *
 * @note    This macro is meant to be used in the low level drivers
 *          implementation only.
 *
 * @param[in] i2cp      pointer to the @p I2CDriver object
 *
 * @notapi
 */
#define _i2c_isr_code(i2cp, i2cscfg) {                                      \
  (i2cp)->id_state = I2C_READY;                                             \
  _i2c_wakeup_isr(i2cp);                                                    \
}

/**
 * @brief   Error ISR code.
 * @details This code handles the portable part of the ISR code:
 *          - Waiting thread wakeup.
 *          - Driver state transitions.
 *
 * @note    This macro is meant to be used in the low level drivers
 *          implementation only.
 *
 * @param[in] i2cp      pointer to the @p I2CDriver object
 *
 * @notapi
 */
#define _i2c_isr_err_code(i2cp, i2cscfg) {                                  \
  (i2cp)->id_state = I2C_READY;                                             \
  _i2c_wakeup_isr(i2cp);                                                    \
}

/*===========================================================================*/
/* External declarations.                                                    */
/*===========================================================================*/

#ifdef __cplusplus
extern "C" {
#endif
  void i2cInit(void);
  void i2cObjectInit(I2CDriver *i2cp);
  void i2cStart(I2CDriver *i2cp, const I2CConfig *config);
  void i2cStop(I2CDriver *i2cp);
  i2cflags_t i2cMasterTransmit(I2CDriver *i2cp,
                         uint8_t slave_addr,
                         uint8_t *txbuf, size_t txbytes,
                         uint8_t *rxbuf, size_t rxbytes);
  i2cflags_t i2cMasterReceive(I2CDriver *i2cp,
                        uint8_t slave_addr, uint8_t *rxbuf, size_t rxbytes);
  void i2cAddFlagsI(I2CDriver *i2cp, i2cflags_t mask);
  i2cflags_t i2cGetAndClearFlags(I2CDriver *i2cp);

#if I2C_USE_MUTUAL_EXCLUSION
  void i2cAcquireBus(I2CDriver *i2cp);
  void i2cReleaseBus(I2CDriver *i2cp);
#endif /* I2C_USE_MUTUAL_EXCLUSION */

#ifdef __cplusplus
}
#endif

#endif /* HAL_USE_I2C */

#endif /* _I2C_H_ */

/** @} */