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

#ifndef I2C_H_
#define I2C_H_

#include "ch.h"
#include "hal.h"

#if HAL_USE_I2C || defined(__DOXYGEN__)

/*===========================================================================*/
/* Driver constants.                                                         */
/*===========================================================================*/
#define  I2CD_NO_ERROR                  0
/** @brief Bus Error.*/
#define  I2CD_BUS_ERROR                 0x01
/** @brief Arbitration Lost (master mode).*/
#define  I2CD_ARBITRATION_LOST          0x02
/** @brief Acknowledge Failure.*/
#define  I2CD_ACK_FAILURE               0x04
/** @brief Overrun/Underrun.*/
#define  I2CD_OVERRUN                   0x08
/** @brief PEC Error in reception.*/
#define  I2CD_PEC_ERROR                 0x10
/** @brief Timeout or Tlow Error.*/
#define  I2CD_TIMEOUT                   0x20
/** @brief SMBus Alert.*/
#define  I2CD_SMB_ALERT                 0x40

/*===========================================================================*/
/* Driver pre-compile time settings.                                         */
/*===========================================================================*/
/**
 * @brief   Enables synchronous APIs.
 * @note    Disabling this option saves both code and data space.
 */
#if !defined(I2C_USE_WAIT) || defined(__DOXYGEN__)
#define I2C_USE_WAIT                TRUE
#endif

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

/**
 * @brief Driver state machine possible states.
 */
typedef enum {
  I2C_UNINIT = 0,                           /**< @brief Not initialized.        */
  I2C_STOP = 1,                             /**< @brief Stopped.                */
  I2C_READY = 2,                            /**< @brief Ready.                  */
  I2C_ACTIVE = 3,                           /**< @brief In communication.          */
  I2C_COMPLETE = 4                          /**< @brief Asynchronous operation complete.   */
} i2cstate_t;

#include "i2c_lld.h"

#if I2C_USE_WAIT || defined(__DOXYGEN__)
/**
 * @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)->thread == NULL,                                       \
              "_i2c_wait(), #1", "already waiting");                        \
  (i2cp)->thread = chThdSelf();                                             \
  chSchGoSleepS(THD_STATE_SUSPENDED);                                       \
}

/**
 * @brief   Wakes up the waiting thread.
 *
 * @param[in] i2cp      pointer to the @p I2CDriver object
 *
 * @notapi
 */
#define _i2c_wakeup_isr(i2cp) {                                             \
  if ((i2cp)->thread != NULL) {                                             \
    Thread *tp = (i2cp)->thread;                                            \
    (i2cp)->thread = NULL;                                                  \
    chSysLockFromIsr();                                                     \
    chSchReadyI(tp);                                                        \
    chSysUnlockFromIsr();                                                   \
  }                                                                         \
}
#else /* !I2C_USE_WAIT */
#define _i2c_wait_s(i2cp)
#define _i2c_wakeup_isr(i2cp)
#endif /* !I2C_USE_WAIT */

/**
 * @brief   Common ISR code.
 * @details This code handles the portable part of the ISR code:
 *          - Callback invocation.
 *          - Waiting thread wakeup, if any.
 *          - 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) {                                               \
  (i2cp)->state = I2C_COMPLETE;                                         		\
  if((i2cp)->endcb) {                                                       \
    (i2cp)->endcb(i2cp);                                                    \
  }                                                                         \
  _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);
  void i2cMasterTransmit(I2CDriver *i2cp, uint16_t slave_addr, size_t n, void *txbuf);
  void i2cMasterReceive(I2CDriver *i2cp, uint16_t slave_addr, size_t n, void *rxbuf);
  void i2cAddFlagsI(I2CDriver *i2cp, i2cflags_t mask);
  i2cflags_t i2cGetAndClearFlags(I2CDriver *i2cp);
  uint16_t i2cSMBusAlertResponse(I2CDriver *i2cp);

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


#endif /* CH_HAL_USE_I2C */

#endif /* I2C_H_ */