dma.c

/*
 * dma.c
 *
 * Copyright (c) 2014 Jeremy Garff <jer @ jers.net>
 *
 * 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.
 *     3.  Neither the name of the owner nor the names of its contributors may be used to endorse
 *         or promote products derived from this software without specific prior written permission.
 * 
 * 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 HOLDER 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 <stdint.h>
#include <stdio.h>
#include <string.h>
#include <stdlib.h>
#include <unistd.h>

#include <sys/types.h>
#include <sys/stat.h>
#include <sys/mman.h>

#include "dma.h"


// DMA address mapping by DMA number index
static const uint32_t dma_offset[] =
{
    DMA0_OFFSET,
    DMA1_OFFSET,
    DMA2_OFFSET,
    DMA3_OFFSET,
    DMA4_OFFSET,
    DMA5_OFFSET,
    DMA6_OFFSET,
    DMA7_OFFSET,
    DMA8_OFFSET,
    DMA9_OFFSET,
    DMA10_OFFSET,
    DMA11_OFFSET,
    DMA12_OFFSET,
    DMA13_OFFSET,
    DMA14_OFFSET,
    DMA15_OFFSET,
};


uint32_t dmanum_to_offset(int dmanum)
{
    int array_size = sizeof(dma_offset) / sizeof(dma_offset[0]);

    if (dmanum >= array_size)
    {
        return 0;
    }

    return dma_offset[dmanum];
}