/*
    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 <http://www.gnu.org/licenses/>.
*/

/**
 * @file    AT91SAM7/ext_lld.h
 * @brief   AT91SAM7 EXT subsystem low level driver header.
 *
 * @addtogroup EXT
 * @{
 */

#ifndef _EXT_LLD_H_
#define _EXT_LLD_H_

#if HAL_USE_EXT || defined(__DOXYGEN__)

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

/**
 * @brief    Pointer to the SAM7 AIC register block.
 */
#define SAM7_EXT_AIC    ((AT91PS_AIC *)AT91C_BASE_AIC)

/**
 * @brief    Number of channels within one ext driver.
 */
#define    EXT_MAX_CHANNELS            32

/**
 * @brief    Mask of priority bits in interrupt mode register.
 */
#define SAM7_EXT_PRIORITY_MASK        0x00000007

/**
 * @brief    Shifter for priority bits in interrupt mode register.
 */
#define SAM7_EXT_PRIORITY_SHIFTER    0

/**
 * @brief    Shifter for mode bits in interrupt mode register.
 */
#define SAM7_EXT_MODE_SHIFTER        5

/*
 * On the SAM7 architecture, a single channel can only be enables or disabled
 * Hence, undefine the other channel mode constants
 */
#ifdef EXT_CH_MODE_RISING_EDGE
#undef EXT_CH_MODE_RISING_EDGE
#endif

#ifdef EXT_CH_MODE_FALLING_EDGE
#undef EXT_CH_MODE_FALLING_EDGE
#endif

#ifdef EXT_CH_MODE_BOTH_EDGES
#undef EXT_CH_MODE_BOTH_EDGES
#endif

/**
 * @name    EXT channels mode
 * @{
 */
#define EXT_CH_MODE_ENABLED            1        /**< @brief Channel is enabled. */
/** @} */

/**
 * @name    EXT drivers mode
 * @{
 */
/**
 * @brief   Mask for modes.
 */
#define SAM7_EXT_MODE_MASK            AT91C_AIC_SRCTYPE
/**
 * @brief   Falling edge callback.
 */
#define SAM7_EXT_MODE_FALLING_EDGE    AT91C_AIC_SRCTYPE_EXT_NEGATIVE_EDGE
/**
 * @brief   Rising edge callback.
 */
#define SAM7_EXT_MODE_RISING_EDGE    AT91C_AIC_SRCTYPE_POSITIVE_EDGE
/**
 * @brief   High-level callback.
 */
#define SAM7_EXT_MODE_HIGH_LEVEL    AT91C_AIC_SRCTYPE_HIGH_LEVEL
/**
 * @brief   Low-level callback.
 */
#define SAM7_EXT_MODE_LOW_LEVEL        AT91C_AIC_SRCTYPE_EXT_LOW_LEVEL
/** @} */

/**
 * @name    EXT drivers priorities
 * @{
 */
#define SAM7_EXT_PRIOR_HIGHEST        AT91C_AIC_PRIOR_HIGHEST
#define SAM7_EXT_PRIOR_LOWEST        AT91C_AIC_PRIOR_LOWEST
/** @} */

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

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

/*===========================================================================*/
/* Driver data structures and types.                                         */
/*===========================================================================*/

/**
 * @brief   EXT channel identifier.
 */
typedef uint32_t expchannel_t;

/**
 * @brief   Type of an EXT generic notification callback.
 *
 * @param[in] extp      pointer to the @p EXPDriver object triggering the
 *                      callback
 */
typedef void (*extcallback_t)(EXTDriver *extp, expchannel_t channel);

/**
 * @brief   Channel configuration structure.
 */
typedef struct {
  /**
   * @brief Channel mode.
   */
  uint32_t              mode;
  /**
   * @brief Channel callback.
   * @details  In the STM32 implementation a @p NULL callback pointer is
   *           valid and configures the channel as an event sources instead
   *           of an interrupt source.
   */
  extcallback_t         cb;
} EXTChannelConfig;

/**
 * @brief   Driver configuration structure.
 * @note    It could be empty on some architectures.
 */
typedef struct {
  /**
   * @brief Channel configurations.
   */
  EXTChannelConfig      channels[EXT_MAX_CHANNELS];
  /* End of the mandatory fields.*/

  /**
   * @brief interrupt mode.
   */
  uint32_t              mode;

  /**
   * @brief interrupt priority.
   */
  uint32_t              priority;
} EXTConfig;

/**
 * @brief   Structure representing an EXT driver.
 */
struct EXTDriver {
  /**
   * @brief Driver state.
   */
  extstate_t                state;
  /**
   * @brief Current configuration data.
   */
  const EXTConfig           *config;
  /* End of the mandatory fields.*/
  /**
   * @brief Pointer to the corresponding PIO registers block.
   */
  AT91PS_PIO                pio;
  /**
   * @brief peripheral ID of the corresponding PIO block.
   */
  uint32_t                    pid;
};

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

/**
 * @brief    Computes the content for the interrupt source mode register.
 */
#define SAM7_computeSMR(mode, prio) (                                       \
    ((mode & SAM7_EXT_MODE_MASK) << SAM7_EXT_MODE_SHIFTER) |                \
    ((prio & SAM7_EXT_PRIORITY_MASK) << SAM7_EXT_PRIORITY_SHIFTER)          \
)

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

#if !defined(__DOXYGEN__)
extern EXTDriver EXTDA;
#if (SAM7_PLATFORM == SAM7X128) || (SAM7_PLATFORM == SAM7X256) ||           \
    (SAM7_PLATFORM == SAM7X512)
extern EXTDriver EXTDB;
#endif
#endif

#ifdef __cplusplus
extern "C" {
#endif
  void ext_lld_init(void);
  void ext_lld_start(EXTDriver *extp);
  void ext_lld_stop(EXTDriver *extp);
  void ext_lld_channel_enable(EXTDriver *extp, expchannel_t channel);
  void ext_lld_channel_disable(EXTDriver *extp, expchannel_t channel);
#ifdef __cplusplus
}
#endif

#endif /* HAL_USE_EXT */

#endif /* _EXT_LLD_H_ */

/** @} */