ep93xx-pcm.c

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/*
 * linux/sound/arm/ep93xx-pcm.c - EP93xx ALSA PCM interface
 *
 * Copyright (C) 2006 Lennert Buytenhek <[email protected]>
 * Copyright (C) 2006 Applied Data Systems
 *
 * Rewritten for the SoC audio subsystem (Based on PXA2xx code):
 *   Copyright (c) 2008 Ryan Mallon
 *
 * 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/module.h>
#include <linux/init.h>
#include <linux/device.h>
#include <linux/slab.h>
#include <linux/dmaengine.h>
#include <linux/dma-mapping.h>

#include <sound/core.h>
#include <sound/pcm.h>
#include <sound/pcm_params.h>
#include <sound/soc.h>
#include <sound/dmaengine_pcm.h>

#include <linux/platform_data/dma-ep93xx.h>
#include <mach/hardware.h>
#include <mach/ep93xx-regs.h>

#include "ep93xx-pcm.h"

static const struct snd_pcm_hardware ep93xx_pcm_hardware = {
    .info           = (SNDRV_PCM_INFO_MMAP      |
                   SNDRV_PCM_INFO_MMAP_VALID    |
                   SNDRV_PCM_INFO_INTERLEAVED   |
                   SNDRV_PCM_INFO_BLOCK_TRANSFER),
                   
    .rates          = SNDRV_PCM_RATE_8000_192000,
    .rate_min       = SNDRV_PCM_RATE_8000,
    .rate_max       = SNDRV_PCM_RATE_192000,
    
    .formats        = (SNDRV_PCM_FMTBIT_S16_LE |
                   SNDRV_PCM_FMTBIT_S24_LE |
                   SNDRV_PCM_FMTBIT_S32_LE),
    
    .buffer_bytes_max   = 131072,
    .period_bytes_min   = 32,
    .period_bytes_max   = 32768,
    .periods_min        = 1,
    .periods_max        = 32,
    .fifo_size      = 32,
};

static bool ep93xx_pcm_dma_filter(struct dma_chan *chan, void *filter_param)
{
    struct ep93xx_dma_data *data = filter_param;

    if (data->direction == ep93xx_dma_chan_direction(chan)) {
        chan->private = data;
        return true;
    }

    return false;
}

static int ep93xx_pcm_open(struct snd_pcm_substream *substream)
{
    struct snd_soc_pcm_runtime *rtd = substream->private_data;
    struct snd_soc_dai *cpu_dai = rtd->cpu_dai;
    struct ep93xx_pcm_dma_params *dma_params;
    struct ep93xx_dma_data *dma_data;
    int ret;

    snd_soc_set_runtime_hwparams(substream, &ep93xx_pcm_hardware);

    dma_data = kmalloc(sizeof(*dma_data), GFP_KERNEL);
    if (!dma_data)
        return -ENOMEM;

    dma_params = snd_soc_dai_get_dma_data(cpu_dai, substream);
    dma_data->port = dma_params->dma_port;
    dma_data->name = dma_params->name;
    dma_data->direction = snd_pcm_substream_to_dma_direction(substream);

    ret = snd_dmaengine_pcm_open(substream, ep93xx_pcm_dma_filter, dma_data);
    if (ret) {
        kfree(dma_data);
        return ret;
    }

    snd_dmaengine_pcm_set_data(substream, dma_data);

    return 0;
}

static int ep93xx_pcm_close(struct snd_pcm_substream *substream)
{
    struct dma_data *dma_data = snd_dmaengine_pcm_get_data(substream);

    snd_dmaengine_pcm_close(substream);
    kfree(dma_data);
    return 0;
}

static int ep93xx_pcm_hw_params(struct snd_pcm_substream *substream,
                struct snd_pcm_hw_params *params)
{
    snd_pcm_set_runtime_buffer(substream, &substream->dma_buffer);

    return 0;
}

static int ep93xx_pcm_hw_free(struct snd_pcm_substream *substream)
{
    snd_pcm_set_runtime_buffer(substream, NULL);
    return 0;
}

static int ep93xx_pcm_mmap(struct snd_pcm_substream *substream,
               struct vm_area_struct *vma)
{
    struct snd_pcm_runtime *runtime = substream->runtime;

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

static struct snd_pcm_ops ep93xx_pcm_ops = {
    .open       = ep93xx_pcm_open,
    .close      = ep93xx_pcm_close,
    .ioctl      = snd_pcm_lib_ioctl,
    .hw_params  = ep93xx_pcm_hw_params,
    .hw_free    = ep93xx_pcm_hw_free,
    .trigger    = snd_dmaengine_pcm_trigger,
    .pointer    = snd_dmaengine_pcm_pointer_no_residue,
    .mmap       = ep93xx_pcm_mmap,
};

static int ep93xx_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 = ep93xx_pcm_hardware.buffer_bytes_max;

    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);
    buf->bytes = size;

    return (buf->area == NULL) ? -ENOMEM : 0;
}

static void ep93xx_pcm_free_dma_buffers(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;
    }
}

static u64 ep93xx_pcm_dmamask = DMA_BIT_MASK(32);

static int ep93xx_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 = &ep93xx_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 = ep93xx_pcm_preallocate_dma_buffer(pcm,
                    SNDRV_PCM_STREAM_PLAYBACK);
        if (ret)
            return ret;
    }

    if (pcm->streams[SNDRV_PCM_STREAM_CAPTURE].substream) {
        ret = ep93xx_pcm_preallocate_dma_buffer(pcm,
                    SNDRV_PCM_STREAM_CAPTURE);
        if (ret)
            return ret;
    }

    return 0;
}

static struct snd_soc_platform_driver ep93xx_soc_platform = {
    .ops        = &ep93xx_pcm_ops,
    .pcm_new    = &ep93xx_pcm_new,
    .pcm_free   = &ep93xx_pcm_free_dma_buffers,
};

static int __devinit ep93xx_soc_platform_probe(struct platform_device *pdev)
{
    return snd_soc_register_platform(&pdev->dev, &ep93xx_soc_platform);
}

static int __devexit ep93xx_soc_platform_remove(struct platform_device *pdev)
{
    snd_soc_unregister_platform(&pdev->dev);
    return 0;
}

static struct platform_driver ep93xx_pcm_driver = {
    .driver = {
            .name = "ep93xx-pcm-audio",
            .owner = THIS_MODULE,
    },

    .probe = ep93xx_soc_platform_probe,
    .remove = __devexit_p(ep93xx_soc_platform_remove),
};

module_platform_driver(ep93xx_pcm_driver);

MODULE_AUTHOR("Ryan Mallon");
MODULE_DESCRIPTION("EP93xx ALSA PCM interface");
MODULE_LICENSE("GPL");
MODULE_ALIAS("platform:ep93xx-pcm-audio");