mmp-pcm.c

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/*
 * linux/sound/soc/pxa/mmp-pcm.c
 *
 * Copyright (C) 2011 Marvell International Ltd.
 *
 * 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/module.h>
#include <linux/init.h>
#include <linux/platform_device.h>
#include <linux/slab.h>
#include <linux/dma-mapping.h>
#include <linux/dmaengine.h>
#include <linux/platform_data/dma-mmp_tdma.h>
#include <linux/platform_data/mmp_audio.h>
#include <sound/pxa2xx-lib.h>
#include <sound/core.h>
#include <sound/pcm.h>
#include <sound/pcm_params.h>
#include <sound/soc.h>
#include <sound/dmaengine_pcm.h>

struct mmp_dma_data {
    int ssp_id;
    struct resource *dma_res;
};

#define MMP_PCM_INFO (SNDRV_PCM_INFO_MMAP | \
        SNDRV_PCM_INFO_MMAP_VALID | \
        SNDRV_PCM_INFO_INTERLEAVED |    \
        SNDRV_PCM_INFO_PAUSE |      \
        SNDRV_PCM_INFO_RESUME)

#define MMP_PCM_FORMATS (SNDRV_PCM_FMTBIT_S16_LE | \
             SNDRV_PCM_FMTBIT_S24_LE | \
             SNDRV_PCM_FMTBIT_S32_LE)

static struct snd_pcm_hardware mmp_pcm_hardware[] = {
    {
        .info           = MMP_PCM_INFO,
        .formats        = MMP_PCM_FORMATS,
        .period_bytes_min   = 1024,
        .period_bytes_max   = 2048,
        .periods_min        = 2,
        .periods_max        = 32,
        .buffer_bytes_max   = 4096,
        .fifo_size      = 32,
    },
    {
        .info           = MMP_PCM_INFO,
        .formats        = MMP_PCM_FORMATS,
        .period_bytes_min   = 1024,
        .period_bytes_max   = 2048,
        .periods_min        = 2,
        .periods_max        = 32,
        .buffer_bytes_max   = 4096,
        .fifo_size      = 32,
    },
};

static int mmp_pcm_hw_params(struct snd_pcm_substream *substream,
                  struct snd_pcm_hw_params *params)
{
    struct dma_chan *chan = snd_dmaengine_pcm_get_chan(substream);
    struct snd_soc_pcm_runtime *rtd = substream->private_data;
    struct pxa2xx_pcm_dma_params *dma_params;
    struct dma_slave_config slave_config;
    int ret;

    dma_params = snd_soc_dai_get_dma_data(rtd->cpu_dai, substream);
    if (!dma_params)
        return 0;

    ret = snd_hwparams_to_dma_slave_config(substream, params, &slave_config);
    if (ret)
        return ret;

    if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK) {
        slave_config.dst_addr     = dma_params->dev_addr;
        slave_config.dst_maxburst = 4;
    } else {
        slave_config.src_addr     = dma_params->dev_addr;
        slave_config.src_maxburst = 4;
    }

    ret = dmaengine_slave_config(chan, &slave_config);
    if (ret)
        return ret;

    snd_pcm_set_runtime_buffer(substream, &substream->dma_buffer);

    return 0;
}

static bool filter(struct dma_chan *chan, void *param)
{
    struct mmp_dma_data *dma_data = param;
    bool found = false;
    char *devname;

    devname = kasprintf(GFP_KERNEL, "%s.%d", dma_data->dma_res->name,
        dma_data->ssp_id);
    if ((strcmp(dev_name(chan->device->dev), devname) == 0) &&
        (chan->chan_id == dma_data->dma_res->start)) {
        found = true;
    }

    kfree(devname);
    return found;
}

static int mmp_pcm_open(struct snd_pcm_substream *substream)
{
    struct snd_soc_pcm_runtime *rtd = substream->private_data;
    struct platform_device *pdev = to_platform_device(rtd->platform->dev);
    struct snd_soc_dai *cpu_dai = rtd->cpu_dai;
    struct mmp_dma_data *dma_data;
    struct resource *r;
    int ret;

    r = platform_get_resource(pdev, IORESOURCE_DMA, substream->stream);
    if (!r)
        return -EBUSY;

    snd_soc_set_runtime_hwparams(substream,
                &mmp_pcm_hardware[substream->stream]);
    dma_data = devm_kzalloc(&pdev->dev,
            sizeof(struct mmp_dma_data), GFP_KERNEL);
    if (dma_data == NULL)
        return -ENOMEM;

    dma_data->dma_res = r;
    dma_data->ssp_id = cpu_dai->id;

    ret = snd_dmaengine_pcm_open(substream, filter, dma_data);
    if (ret) {
        devm_kfree(&pdev->dev, dma_data);
        return ret;
    }

    snd_dmaengine_pcm_set_data(substream, dma_data);
    return 0;
}

static int mmp_pcm_close(struct snd_pcm_substream *substream)
{
    struct mmp_dma_data *dma_data = snd_dmaengine_pcm_get_data(substream);
    struct snd_soc_pcm_runtime *rtd = substream->private_data;
    struct platform_device *pdev = to_platform_device(rtd->platform->dev);

    snd_dmaengine_pcm_close(substream);
    devm_kfree(&pdev->dev, dma_data);
    return 0;
}

static int mmp_pcm_mmap(struct snd_pcm_substream *substream,
             struct vm_area_struct *vma)
{
    struct snd_pcm_runtime *runtime = substream->runtime;
    unsigned long off = vma->vm_pgoff;

    vma->vm_page_prot = pgprot_noncached(vma->vm_page_prot);
    return remap_pfn_range(vma, vma->vm_start,
        __phys_to_pfn(runtime->dma_addr) + off,
        vma->vm_end - vma->vm_start, vma->vm_page_prot);
}

struct snd_pcm_ops mmp_pcm_ops = {
    .open       = mmp_pcm_open,
    .close      = mmp_pcm_close,
    .ioctl      = snd_pcm_lib_ioctl,
    .hw_params  = mmp_pcm_hw_params,
    .trigger    = snd_dmaengine_pcm_trigger,
    .pointer    = snd_dmaengine_pcm_pointer,
    .mmap       = mmp_pcm_mmap,
};

static void mmp_pcm_free_dma_buffers(struct snd_pcm *pcm)
{
    struct snd_pcm_substream *substream;
    struct snd_dma_buffer *buf;
    int stream;
    struct gen_pool *gpool;

    gpool = sram_get_gpool("asram");
    if (!gpool)
        return;

    for (stream = 0; stream < 2; stream++) {
        size_t size = mmp_pcm_hardware[stream].buffer_bytes_max;

        substream = pcm->streams[stream].substream;
        if (!substream)
            continue;

        buf = &substream->dma_buffer;
        if (!buf->area)
            continue;
        gen_pool_free(gpool, (unsigned long)buf->area, size);
        buf->area = NULL;
    }

    return;
}

static int mmp_pcm_preallocate_dma_buffer(struct snd_pcm_substream *substream,
                                int stream)
{
    struct snd_dma_buffer *buf = &substream->dma_buffer;
    size_t size = mmp_pcm_hardware[stream].buffer_bytes_max;
    struct gen_pool *gpool;

    buf->dev.type = SNDRV_DMA_TYPE_DEV;
    buf->dev.dev = substream->pcm->card->dev;
    buf->private_data = NULL;

    gpool = sram_get_gpool("asram");
    if (!gpool)
        return -ENOMEM;

    buf->area = (unsigned char *)gen_pool_alloc(gpool, size);
    if (!buf->area)
        return -ENOMEM;
    buf->addr = gen_pool_virt_to_phys(gpool, (unsigned long)buf->area);
    buf->bytes = size;
    return 0;
}

int mmp_pcm_new(struct snd_soc_pcm_runtime *rtd)
{
    struct snd_pcm_substream *substream;
    struct snd_pcm *pcm = rtd->pcm;
    int ret = 0, stream;

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

        ret = mmp_pcm_preallocate_dma_buffer(substream, stream);
        if (ret)
            goto err;
    }

    return 0;

err:
    mmp_pcm_free_dma_buffers(pcm);
    return ret;
}

struct snd_soc_platform_driver mmp_soc_platform = {
    .ops        = &mmp_pcm_ops,
    .pcm_new    = mmp_pcm_new,
    .pcm_free   = mmp_pcm_free_dma_buffers,
};

static __devinit int mmp_pcm_probe(struct platform_device *pdev)
{
    struct mmp_audio_platdata *pdata = pdev->dev.platform_data;

    if (pdata) {
        mmp_pcm_hardware[SNDRV_PCM_STREAM_PLAYBACK].buffer_bytes_max =
                        pdata->buffer_max_playback;
        mmp_pcm_hardware[SNDRV_PCM_STREAM_PLAYBACK].period_bytes_max =
                        pdata->period_max_playback;
        mmp_pcm_hardware[SNDRV_PCM_STREAM_CAPTURE].buffer_bytes_max =
                        pdata->buffer_max_capture;
        mmp_pcm_hardware[SNDRV_PCM_STREAM_CAPTURE].period_bytes_max =
                        pdata->period_max_capture;
    }
    return snd_soc_register_platform(&pdev->dev, &mmp_soc_platform);
}

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

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

    .probe = mmp_pcm_probe,
    .remove = __devexit_p(mmp_pcm_remove),
};

module_platform_driver(mmp_pcm_driver);

MODULE_AUTHOR("Leo Yan <[email protected]>");
MODULE_DESCRIPTION("MMP Soc Audio DMA module");
MODULE_LICENSE("GPL");