soc-utils.c

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/*
 * soc-util.c  --  ALSA SoC Audio Layer utility functions
 *
 * Copyright 2009 Wolfson Microelectronics PLC.
 *
 * Author: Mark Brown <[email protected]>
 *         Liam Girdwood <[email protected]>
 *         
 *
 *  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/platform_device.h>
#include <linux/export.h>
#include <sound/core.h>
#include <sound/pcm.h>
#include <sound/pcm_params.h>
#include <sound/soc.h>

int snd_soc_calc_frame_size(int sample_size, int channels, int tdm_slots)
{
    return sample_size * channels * tdm_slots;
}
EXPORT_SYMBOL_GPL(snd_soc_calc_frame_size);

int snd_soc_params_to_frame_size(struct snd_pcm_hw_params *params)
{
    int sample_size;

    sample_size = snd_pcm_format_width(params_format(params));
    if (sample_size < 0)
        return sample_size;

    return snd_soc_calc_frame_size(sample_size, params_channels(params),
                       1);
}
EXPORT_SYMBOL_GPL(snd_soc_params_to_frame_size);

int snd_soc_calc_bclk(int fs, int sample_size, int channels, int tdm_slots)
{
    return fs * snd_soc_calc_frame_size(sample_size, channels, tdm_slots);
}
EXPORT_SYMBOL_GPL(snd_soc_calc_bclk);

int snd_soc_params_to_bclk(struct snd_pcm_hw_params *params)
{
    int ret;

    ret = snd_soc_params_to_frame_size(params);

    if (ret > 0)
        return ret * params_rate(params);
    else
        return ret;
}
EXPORT_SYMBOL_GPL(snd_soc_params_to_bclk);

static const struct snd_pcm_hardware dummy_dma_hardware = {
    .formats        = 0xffffffff,
    .channels_min       = 1,
    .channels_max       = UINT_MAX,

    /* Random values to keep userspace happy when checking constraints */
    .info           = SNDRV_PCM_INFO_INTERLEAVED |
                  SNDRV_PCM_INFO_BLOCK_TRANSFER,
    .buffer_bytes_max   = 128*1024,
    .period_bytes_min   = PAGE_SIZE,
    .period_bytes_max   = PAGE_SIZE*2,
    .periods_min        = 2,
    .periods_max        = 128,
};

static int dummy_dma_open(struct snd_pcm_substream *substream)
{
    snd_soc_set_runtime_hwparams(substream, &dummy_dma_hardware);

    return 0;
}

static struct snd_pcm_ops dummy_dma_ops = {
    .open       = dummy_dma_open,
    .ioctl      = snd_pcm_lib_ioctl,
};

static struct snd_soc_platform_driver dummy_platform = {
    .ops = &dummy_dma_ops,
};

static struct snd_soc_codec_driver dummy_codec;
static struct snd_soc_dai_driver dummy_dai = {
    .name = "snd-soc-dummy-dai",
};

static __devinit int snd_soc_dummy_probe(struct platform_device *pdev)
{
    int ret;

    ret = snd_soc_register_codec(&pdev->dev, &dummy_codec, &dummy_dai, 1);
    if (ret < 0)
        return ret;

    ret = snd_soc_register_platform(&pdev->dev, &dummy_platform);
    if (ret < 0) {
        snd_soc_unregister_codec(&pdev->dev);
        return ret;
    }

    return ret;
}

static __devexit int snd_soc_dummy_remove(struct platform_device *pdev)
{
    snd_soc_unregister_platform(&pdev->dev);
    snd_soc_unregister_codec(&pdev->dev);

    return 0;
}

static struct platform_driver soc_dummy_driver = {
    .driver = {
        .name = "snd-soc-dummy",
        .owner = THIS_MODULE,
    },
    .probe = snd_soc_dummy_probe,
    .remove = __devexit_p(snd_soc_dummy_remove),
};

static struct platform_device *soc_dummy_dev;

int __init snd_soc_util_init(void)
{
    int ret;

    soc_dummy_dev = platform_device_alloc("snd-soc-dummy", -1);
    if (!soc_dummy_dev)
        return -ENOMEM;

    ret = platform_device_add(soc_dummy_dev);
    if (ret != 0) {
        platform_device_put(soc_dummy_dev);
        return ret;
    }

    ret = platform_driver_register(&soc_dummy_driver);
    if (ret != 0)
        platform_device_unregister(soc_dummy_dev);

    return ret;
}

void __exit snd_soc_util_exit(void)
{
    platform_device_unregister(soc_dummy_dev);
    platform_driver_unregister(&soc_dummy_driver);
}