imx-pcm.c

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/*
 * Copyright 2009 Sascha Hauer <[email protected]>
 *
 * This code is based on code copyrighted by Freescale,
 * Liam Girdwood, Javier Martin and probably others.
 *
 * This program 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 2 of the  License, or (at your
 * option) any later version.
 */

#include <linux/dma-mapping.h>
#include <linux/module.h>
#include <sound/pcm.h>
#include <sound/soc.h>
#include "imx-pcm.h"

int snd_imx_pcm_mmap(struct snd_pcm_substream *substream,
        struct vm_area_struct *vma)
{
    struct snd_pcm_runtime *runtime = substream->runtime;
    int ret;

    ret = dma_mmap_writecombine(substream->pcm->card->dev, vma,
        runtime->dma_area, runtime->dma_addr, runtime->dma_bytes);

    pr_debug("%s: ret: %d %p 0x%08x 0x%08x\n", __func__, ret,
            runtime->dma_area,
            runtime->dma_addr,
            runtime->dma_bytes);
    return ret;
}
EXPORT_SYMBOL_GPL(snd_imx_pcm_mmap);

static int imx_pcm_preallocate_dma_buffer(struct snd_pcm *pcm, int stream)
{
    struct snd_pcm_substream *substream = pcm->streams[stream].substream;
    struct snd_dma_buffer *buf = &substream->dma_buffer;
    size_t size = IMX_SSI_DMABUF_SIZE;

    buf->dev.type = SNDRV_DMA_TYPE_DEV;
    buf->dev.dev = pcm->card->dev;
    buf->private_data = NULL;
    buf->area = dma_alloc_writecombine(pcm->card->dev, size,
                       &buf->addr, GFP_KERNEL);
    if (!buf->area)
        return -ENOMEM;
    buf->bytes = size;

    return 0;
}

static u64 imx_pcm_dmamask = DMA_BIT_MASK(32);

int imx_pcm_new(struct snd_soc_pcm_runtime *rtd)
{
    struct snd_card *card = rtd->card->snd_card;
    struct snd_pcm *pcm = rtd->pcm;
    int ret = 0;

    if (!card->dev->dma_mask)
        card->dev->dma_mask = &imx_pcm_dmamask;
    if (!card->dev->coherent_dma_mask)
        card->dev->coherent_dma_mask = DMA_BIT_MASK(32);
    if (pcm->streams[SNDRV_PCM_STREAM_PLAYBACK].substream) {
        ret = imx_pcm_preallocate_dma_buffer(pcm,
            SNDRV_PCM_STREAM_PLAYBACK);
        if (ret)
            goto out;
    }

    if (pcm->streams[SNDRV_PCM_STREAM_CAPTURE].substream) {
        ret = imx_pcm_preallocate_dma_buffer(pcm,
            SNDRV_PCM_STREAM_CAPTURE);
        if (ret)
            goto out;
    }

out:
    return ret;
}
EXPORT_SYMBOL_GPL(imx_pcm_new);

void imx_pcm_free(struct snd_pcm *pcm)
{
    struct snd_pcm_substream *substream;
    struct snd_dma_buffer *buf;
    int stream;

    for (stream = 0; stream < 2; stream++) {
        substream = pcm->streams[stream].substream;
        if (!substream)
            continue;

        buf = &substream->dma_buffer;
        if (!buf->area)
            continue;

        dma_free_writecombine(pcm->card->dev, buf->bytes,
                      buf->area, buf->addr);
        buf->area = NULL;
    }
}
EXPORT_SYMBOL_GPL(imx_pcm_free);