/*
    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.c
 * @brief   AT91SAM7 EXT subsystem low level driver source.
 *
 * @addtogroup EXT
 * @{
 */

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

#if HAL_USE_EXT || defined(__DOXYGEN__)

/*===========================================================================*/
/* Driver local definitions.                                                 */
/*===========================================================================*/

/*===========================================================================*/
/* Driver exported variables.                                                */
/*===========================================================================*/

/**
 * @brief   EXTDA driver identifier.
 */
EXTDriver EXTDA;

#if (SAM7_PLATFORM == SAM7X128) || (SAM7_PLATFORM == SAM7X256) || \
    (SAM7_PLATFORM == SAM7X512) || (SAM7_PLATFORM == SAM7A3)
/**
 * @brief   EXTDB driver identifier.
 */
EXTDriver EXTDB;
#endif

/*===========================================================================*/
/* Driver local variables.                                                   */
/*===========================================================================*/

/*===========================================================================*/
/* Driver local functions.                                                   */
/*===========================================================================*/

/**
 * @brief   Handles external interrupts.
 *
 * @param[in] extp      pointer to the driver that received the interrupt
 */
static void ext_lld_serveInterrupt(EXTDriver *extp) {
  uint32_t irqFlags;
  uint32_t ch;

  chSysLockFromIsr();

  /* Read flags of pending PIO interrupts.*/
  irqFlags = extp->pio->PIO_ISR;

  /* Call callback function for any pending interrupt.*/
  for(ch = 0; ch < EXT_MAX_CHANNELS; ch++) {

    /* Check if the channel is activated and if its IRQ flag is set.*/
    if((extp->config->channels[ch].mode &
        EXT_CH_MODE_ENABLED & EXT_CH_MODE_EDGES_MASK)
        && ((1 << ch) & irqFlags)) {
      (extp->config->channels[ch].cb)(extp, ch);
    }
  }

  chSysUnlockFromIsr();

  AT91C_BASE_AIC->AIC_EOICR = 0;
}

/*===========================================================================*/
/* Driver interrupt handlers.                                                */
/*===========================================================================*/

/**
 * @brief   EXTI[0] interrupt handler.
 *
 * @isr
 */
CH_IRQ_HANDLER(EXTIA_IRQHandler) {

  CH_IRQ_PROLOGUE();

  ext_lld_serveInterrupt(&EXTDA);

  CH_IRQ_EPILOGUE();
}

#if (SAM7_PLATFORM == SAM7X128) || (SAM7_PLATFORM == SAM7X256) || \
    (SAM7_PLATFORM == SAM7X512) || (SAM7_PLATFORM == SAM7A3)
/**
 * @brief   EXTI[1] interrupt handler.
 *
 * @isr
 */
CH_IRQ_HANDLER(EXTIB_IRQHandler) {
  CH_IRQ_PROLOGUE();

  ext_lld_serveInterrupt(&EXTDB);

  CH_IRQ_EPILOGUE();
}
#endif

/*===========================================================================*/
/* Driver exported functions.                                                */
/*===========================================================================*/

/**
 * @brief   Low level EXT driver initialization.
 *
 * @notapi
 */
void ext_lld_init(void) {

  /* Driver initialization.*/
  extObjectInit(&EXTDA);

  /* Set PIO base addresses.*/
  EXTDA.pio = AT91C_BASE_PIOA;

  /* Set peripheral IDs.*/
  EXTDA.pid = AT91C_ID_PIOA;

#if (SAM7_PLATFORM == SAM7X128) || (SAM7_PLATFORM == SAM7X256) || \
    (SAM7_PLATFORM == SAM7X512) || (SAM7_PLATFORM == SAM7A3)
  /* Same for PIOB.*/
  extObjectInit(&EXTDB);
  EXTDB.pio = AT91C_BASE_PIOB;
  EXTDB.pid = AT91C_ID_PIOB;
#endif
}

/**
 * @brief   Configures and activates the EXT peripheral.
 *
 * @param[in] extp      pointer to the @p EXTDriver object
 *
 * @notapi
 */
void ext_lld_start(EXTDriver *extp) {
  uint16_t ch;
  uint32_t ier = 0;
  const EXTConfig *config = extp->config;

  switch(extp->pid) {
  case AT91C_ID_PIOA:
    AIC_ConfigureIT(AT91C_ID_PIOA, SAM7_computeSMR(config->mode,
                                                   config->priority),
                                                   EXTIA_IRQHandler);
    break;
#if (SAM7_PLATFORM == SAM7X128) || (SAM7_PLATFORM == SAM7X256) || \
    (SAM7_PLATFORM == SAM7X512) || (SAM7_PLATFORM == SAM7A3)
  case AT91C_ID_PIOB:
    AIC_ConfigureIT(AT91C_ID_PIOB, SAM7_computeSMR(config->mode,
                                                   config->priority),
                                                   EXTIB_IRQHandler);
    break;
#endif
  }

  /* Enable and Disable channels with respect to config.*/
  for(ch = 0; ch < EXT_MAX_CHANNELS; ch++) {
    ier |= (config->channels[ch].mode & EXT_CH_MODE_EDGES_MASK & EXT_CH_MODE_ENABLED ? 1 : 0) << ch;
  }
  extp->pio->PIO_IER = ier;
  extp->pio->PIO_IDR = ~ier;

  /* Enable interrupt on corresponding PIO port in AIC.*/
  AIC_EnableIT(extp->pid);
}

/**
 * @brief   Deactivates the EXT peripheral.
 *
 * @param[in] extp      pointer to the @p EXTDriver object
 *
 * @notapi
 */
void ext_lld_stop(EXTDriver *extp) {

  /* Disable interrupt on corresponding PIO port in AIC.*/
  AIC_DisableIT(extp->pid);
}

/**
 * @brief   Enables an EXT channel.
 *
 * @param[in] extp      pointer to the @p EXTDriver object
 * @param[in] channel   channel to be enabled
 *
 * @notapi
 */
void ext_lld_channel_enable(EXTDriver *extp, expchannel_t channel) {

  chDbgCheck((extp->config->channels[channel].cb != NULL),
      "Call back pointer can not be NULL");

  extp->pio->PIO_IER = (1 << channel);
}

/**
 * @brief   Disables an EXT channel.
 *
 * @param[in] extp      pointer to the @p EXTDriver object
 * @param[in] channel   channel to be disabled
 *
 * @notapi
 */
void ext_lld_channel_disable(EXTDriver *extp, expchannel_t channel) {

  extp->pio->PIO_IDR = (1 << channel);
}

#endif /* HAL_USE_EXT */

/** @} */