imx-pcm-dma.c

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/*
 * imx-pcm-dma-mx2.c  --  ALSA Soc Audio Layer
 *
 * 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/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/types.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 <linux/platform_data/dma-imx.h>

#include "imx-pcm.h"

static bool filter(struct dma_chan *chan, void *param)
{
    if (!imx_dma_is_general_purpose(chan))
        return false;

    chan->private = param;

    return true;
}

static int snd_imx_pcm_hw_params(struct snd_pcm_substream *substream,
                struct snd_pcm_hw_params *params)
{
    struct snd_soc_pcm_runtime *rtd = substream->private_data;
    struct dma_chan *chan = snd_dmaengine_pcm_get_chan(substream);
    struct imx_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);

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

    slave_config.device_fc = false;

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

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

    snd_pcm_set_runtime_buffer(substream, &substream->dma_buffer);

    return 0;
}

static struct snd_pcm_hardware snd_imx_hardware = {
    .info = SNDRV_PCM_INFO_INTERLEAVED |
        SNDRV_PCM_INFO_BLOCK_TRANSFER |
        SNDRV_PCM_INFO_MMAP |
        SNDRV_PCM_INFO_MMAP_VALID |
        SNDRV_PCM_INFO_PAUSE |
        SNDRV_PCM_INFO_RESUME,
    .formats = SNDRV_PCM_FMTBIT_S16_LE,
    .rate_min = 8000,
    .channels_min = 2,
    .channels_max = 2,
    .buffer_bytes_max = IMX_SSI_DMABUF_SIZE,
    .period_bytes_min = 128,
    .period_bytes_max = 65535, /* Limited by SDMA engine */
    .periods_min = 2,
    .periods_max = 255,
    .fifo_size = 0,
};

static int snd_imx_open(struct snd_pcm_substream *substream)
{
    struct snd_soc_pcm_runtime *rtd = substream->private_data;
    struct imx_pcm_dma_params *dma_params;
    struct imx_dma_data *dma_data;
    int ret;

    snd_soc_set_runtime_hwparams(substream, &snd_imx_hardware);

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

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

    dma_data->peripheral_type = dma_params->shared_peripheral ?
                    IMX_DMATYPE_SSI_SP : IMX_DMATYPE_SSI;
    dma_data->priority = DMA_PRIO_HIGH;
    dma_data->dma_request = dma_params->dma;

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

    snd_dmaengine_pcm_set_data(substream, dma_data);

    return 0;
}

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

    snd_dmaengine_pcm_close(substream);
    kfree(dma_data);

    return 0;
}

static struct snd_pcm_ops imx_pcm_ops = {
    .open       = snd_imx_open,
    .close      = snd_imx_close,
    .ioctl      = snd_pcm_lib_ioctl,
    .hw_params  = snd_imx_pcm_hw_params,
    .trigger    = snd_dmaengine_pcm_trigger,
    .pointer    = snd_dmaengine_pcm_pointer_no_residue,
    .mmap       = snd_imx_pcm_mmap,
};

static struct snd_soc_platform_driver imx_soc_platform_mx2 = {
    .ops        = &imx_pcm_ops,
    .pcm_new    = imx_pcm_new,
    .pcm_free   = imx_pcm_free,
};

static int __devinit imx_soc_platform_probe(struct platform_device *pdev)
{
    return snd_soc_register_platform(&pdev->dev, &imx_soc_platform_mx2);
}

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

static struct platform_driver imx_pcm_driver = {
    .driver = {
            .name = "imx-pcm-audio",
            .owner = THIS_MODULE,
    },
    .probe = imx_soc_platform_probe,
    .remove = __devexit_p(imx_soc_platform_remove),
};

module_platform_driver(imx_pcm_driver);
MODULE_LICENSE("GPL");
MODULE_ALIAS("platform:imx-pcm-audio");