/* SPDX-License-Identifier: BSD-2-Clause */

/**
 * @file
 *
 * @ingroup RTEMSBSPsARMLPC24XX_dma
 *
 * @brief Direct memory access (DMA) support.
 */

/*
 * Copyright (c) 2008-2011 embedded brains GmbH.  All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
 * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
 * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
 * POSSIBILITY OF SUCH DAMAGE.
 */

#include <rtems/endian.h>

#include <bsp/lpc24xx.h>
#include <bsp/dma.h>
#include <bsp/io.h>

/**
 * @brief Table that indicates if a channel is currently occupied.
 */
static bool lpc24xx_dma_channel_occupation [GPDMA_CH_NUMBER];

void lpc24xx_dma_initialize(void)
{
  /* Enable module power */
  lpc24xx_module_enable(LPC24XX_MODULE_GPDMA, LPC24XX_MODULE_PCLK_DEFAULT);

  /* Disable module */
  GPDMA_CONFIG = 0;

  /* Reset registers */
  GPDMA_SOFT_SREQ = 0;
  GPDMA_SOFT_BREQ = 0;
  GPDMA_SOFT_LSREQ = 0;
  GPDMA_SOFT_LBREQ = 0;
  GPDMA_SYNC = 0;
  GPDMA_CH0_CFG = 0;
  GPDMA_CH1_CFG = 0;

  /* Enable module */
  #if BYTE_ORDER == LITTLE_ENDIAN
    GPDMA_CONFIG = GPDMA_CONFIG_EN;
  #else
    GPDMA_CONFIG = GPDMA_CONFIG_EN | GPDMA_CONFIG_MODE;
  #endif
}

rtems_status_code lpc24xx_dma_channel_obtain(unsigned channel)
{
  if (channel < GPDMA_CH_NUMBER) {
    rtems_interrupt_level level;
    bool occupation = true;

    rtems_interrupt_disable(level);
    occupation = lpc24xx_dma_channel_occupation [channel];
    lpc24xx_dma_channel_occupation [channel] = true;
    rtems_interrupt_enable(level);

    return occupation ? RTEMS_RESOURCE_IN_USE : RTEMS_SUCCESSFUL;
  } else {
    return RTEMS_INVALID_ID;
  }
}

void lpc24xx_dma_channel_release(unsigned channel)
{
  if (channel < GPDMA_CH_NUMBER) {
    lpc24xx_dma_channel_occupation [channel] = false;
  }
}

void lpc24xx_dma_channel_disable(unsigned channel, bool force)
{
  if (channel < GPDMA_CH_NUMBER) {
    volatile lpc24xx_dma_channel *ch = GPDMA_CH_BASE_ADDR(channel);
    uint32_t cfg = ch->cfg;

    if (!force) {
      /* Halt */
      ch->cfg |= GPDMA_CH_CFG_HALT;

      /* Wait for inactive */
      do {
        cfg = ch->cfg;
      } while ((cfg & GPDMA_CH_CFG_ACTIVE) != 0);
    }

    /* Disable */
    ch->cfg &= ~GPDMA_CH_CFG_EN;
  }
}