pxa2xx-pcm.c

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/*
 * linux/sound/arm/pxa2xx-pcm.c -- ALSA PCM interface for the Intel PXA2xx chip
 *
 * Author:  Nicolas Pitre
 * Created: Nov 30, 2004
 * Copyright:   (C) 2004 MontaVista Software, Inc.
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License version 2 as
 * published by the Free Software Foundation.
 */

#include <linux/dma-mapping.h>
#include <linux/module.h>

#include <sound/core.h>
#include <sound/soc.h>
#include <sound/pxa2xx-lib.h>

#include "../../arm/pxa2xx-pcm.h"

static int pxa2xx_pcm_hw_params(struct snd_pcm_substream *substream,
    struct snd_pcm_hw_params *params)
{
    struct snd_pcm_runtime *runtime = substream->runtime;
    struct pxa2xx_runtime_data *prtd = runtime->private_data;
    struct snd_soc_pcm_runtime *rtd = substream->private_data;
    struct pxa2xx_pcm_dma_params *dma;
    int ret;

    dma = snd_soc_dai_get_dma_data(rtd->cpu_dai, substream);

    /* return if this is a bufferless transfer e.g.
     * codec <--> BT codec or GSM modem -- lg FIXME */
    if (!dma)
        return 0;

    /* this may get called several times by oss emulation
     * with different params */
    if (prtd->params == NULL) {
        prtd->params = dma;
        ret = pxa_request_dma(prtd->params->name, DMA_PRIO_LOW,
                  pxa2xx_pcm_dma_irq, substream);
        if (ret < 0)
            return ret;
        prtd->dma_ch = ret;
    } else if (prtd->params != dma) {
        pxa_free_dma(prtd->dma_ch);
        prtd->params = dma;
        ret = pxa_request_dma(prtd->params->name, DMA_PRIO_LOW,
                  pxa2xx_pcm_dma_irq, substream);
        if (ret < 0)
            return ret;
        prtd->dma_ch = ret;
    }

    return __pxa2xx_pcm_hw_params(substream, params);
}

static int pxa2xx_pcm_hw_free(struct snd_pcm_substream *substream)
{
    struct pxa2xx_runtime_data *prtd = substream->runtime->private_data;

    __pxa2xx_pcm_hw_free(substream);

    if (prtd->dma_ch >= 0) {
        pxa_free_dma(prtd->dma_ch);
        prtd->dma_ch = -1;
        prtd->params = NULL;
    }

    return 0;
}

static struct snd_pcm_ops pxa2xx_pcm_ops = {
    .open       = __pxa2xx_pcm_open,
    .close      = __pxa2xx_pcm_close,
    .ioctl      = snd_pcm_lib_ioctl,
    .hw_params  = pxa2xx_pcm_hw_params,
    .hw_free    = pxa2xx_pcm_hw_free,
    .prepare    = __pxa2xx_pcm_prepare,
    .trigger    = pxa2xx_pcm_trigger,
    .pointer    = pxa2xx_pcm_pointer,
    .mmap       = pxa2xx_pcm_mmap,
};

static u64 pxa2xx_pcm_dmamask = DMA_BIT_MASK(32);

static int pxa2xx_soc_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 = &pxa2xx_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 = pxa2xx_pcm_preallocate_dma_buffer(pcm,
            SNDRV_PCM_STREAM_PLAYBACK);
        if (ret)
            goto out;
    }

    if (pcm->streams[SNDRV_PCM_STREAM_CAPTURE].substream) {
        ret = pxa2xx_pcm_preallocate_dma_buffer(pcm,
            SNDRV_PCM_STREAM_CAPTURE);
        if (ret)
            goto out;
    }
 out:
    return ret;
}

static struct snd_soc_platform_driver pxa2xx_soc_platform = {
    .ops    = &pxa2xx_pcm_ops,
    .pcm_new    = pxa2xx_soc_pcm_new,
    .pcm_free   = pxa2xx_pcm_free_dma_buffers,
};

static int __devinit pxa2xx_soc_platform_probe(struct platform_device *pdev)
{
    return snd_soc_register_platform(&pdev->dev, &pxa2xx_soc_platform);
}

static int __devexit pxa2xx_soc_platform_remove(struct platform_device *pdev)
{
    snd_soc_unregister_platform(&pdev->dev);
    return 0;
}

static struct platform_driver pxa_pcm_driver = {
    .driver = {
            .name = "pxa-pcm-audio",
            .owner = THIS_MODULE,
    },

    .probe = pxa2xx_soc_platform_probe,
    .remove = __devexit_p(pxa2xx_soc_platform_remove),
};

module_platform_driver(pxa_pcm_driver);

MODULE_AUTHOR("Nicolas Pitre");
MODULE_DESCRIPTION("Intel PXA2xx PCM DMA module");
MODULE_LICENSE("GPL");