mxs-pcm.c

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/*
 * Copyright (C) 2011 Freescale Semiconductor, Inc. All Rights Reserved.
 *
 * Based on sound/soc/imx/imx-pcm-dma-mx2.c
 *
 * 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.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License along
 * with this program; if not, write to the Free Software Foundation, Inc.,
 * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
 */

#include <linux/clk.h>
#include <linux/delay.h>
#include <linux/device.h>
#include <linux/dma-mapping.h>
#include <linux/init.h>
#include <linux/interrupt.h>
#include <linux/module.h>
#include <linux/platform_device.h>
#include <linux/slab.h>
#include <linux/dmaengine.h>
#include <linux/fsl/mxs-dma.h>

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

#include "mxs-pcm.h"

struct mxs_pcm_dma_data {
    struct mxs_dma_data dma_data;
    struct mxs_pcm_dma_params *dma_params;
};

static struct snd_pcm_hardware snd_mxs_hardware = {
    .info           = SNDRV_PCM_INFO_MMAP |
                  SNDRV_PCM_INFO_MMAP_VALID |
                  SNDRV_PCM_INFO_PAUSE |
                  SNDRV_PCM_INFO_RESUME |
                  SNDRV_PCM_INFO_INTERLEAVED,
    .formats        = SNDRV_PCM_FMTBIT_S16_LE |
                  SNDRV_PCM_FMTBIT_S20_3LE |
                  SNDRV_PCM_FMTBIT_S24_LE,
    .channels_min       = 2,
    .channels_max       = 2,
    .period_bytes_min   = 32,
    .period_bytes_max   = 8192,
    .periods_min        = 1,
    .periods_max        = 52,
    .buffer_bytes_max   = 64 * 1024,
    .fifo_size      = 32,

};

static bool filter(struct dma_chan *chan, void *param)
{
    struct mxs_pcm_dma_data *pcm_dma_data = param;
    struct mxs_pcm_dma_params *dma_params = pcm_dma_data->dma_params;

    if (!mxs_dma_is_apbx(chan))
        return false;

    if (chan->chan_id != dma_params->chan_num)
        return false;

    chan->private = &pcm_dma_data->dma_data;

    return true;
}

static int snd_mxs_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 snd_mxs_open(struct snd_pcm_substream *substream)
{
    struct snd_soc_pcm_runtime *rtd = substream->private_data;
    struct mxs_pcm_dma_data *pcm_dma_data;
    int ret;

    pcm_dma_data = kzalloc(sizeof(*pcm_dma_data), GFP_KERNEL);
    if (pcm_dma_data == NULL)
        return -ENOMEM;

    pcm_dma_data->dma_params = snd_soc_dai_get_dma_data(rtd->cpu_dai, substream);
    pcm_dma_data->dma_data.chan_irq = pcm_dma_data->dma_params->chan_irq;

    ret = snd_dmaengine_pcm_open(substream, filter, pcm_dma_data);
    if (ret) {
        kfree(pcm_dma_data);
        return ret;
    }

    snd_soc_set_runtime_hwparams(substream, &snd_mxs_hardware);

    snd_dmaengine_pcm_set_data(substream, pcm_dma_data);

    return 0;
}

static int snd_mxs_close(struct snd_pcm_substream *substream)
{
    struct mxs_pcm_dma_data *pcm_dma_data = snd_dmaengine_pcm_get_data(substream);

    snd_dmaengine_pcm_close(substream);
    kfree(pcm_dma_data);

    return 0;
}

static int snd_mxs_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 mxs_pcm_ops = {
    .open       = snd_mxs_open,
    .close      = snd_mxs_close,
    .ioctl      = snd_pcm_lib_ioctl,
    .hw_params  = snd_mxs_pcm_hw_params,
    .trigger    = snd_dmaengine_pcm_trigger,
    .pointer    = snd_dmaengine_pcm_pointer_no_residue,
    .mmap       = snd_mxs_pcm_mmap,
};

static int mxs_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 = snd_mxs_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);
    if (!buf->area)
        return -ENOMEM;
    buf->bytes = size;

    return 0;
}

static u64 mxs_pcm_dmamask = DMA_BIT_MASK(32);
static int mxs_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 = &mxs_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 = mxs_pcm_preallocate_dma_buffer(pcm,
            SNDRV_PCM_STREAM_PLAYBACK);
        if (ret)
            goto out;
    }

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

out:
    return ret;
}

static void mxs_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;
    }
}

static struct snd_soc_platform_driver mxs_soc_platform = {
    .ops        = &mxs_pcm_ops,
    .pcm_new    = mxs_pcm_new,
    .pcm_free   = mxs_pcm_free,
};

int __devinit mxs_pcm_platform_register(struct device *dev)
{
    return snd_soc_register_platform(dev, &mxs_soc_platform);
}
EXPORT_SYMBOL_GPL(mxs_pcm_platform_register);

void __devexit mxs_pcm_platform_unregister(struct device *dev)
{
    snd_soc_unregister_platform(dev);
}
EXPORT_SYMBOL_GPL(mxs_pcm_platform_unregister);

MODULE_LICENSE("GPL");