ac97.c

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/*
 * ac97.c  --  ALSA Soc AC97 codec support
 *
 * Copyright 2005 Wolfson Microelectronics PLC.
 * Author: 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.
 *
 * Generic AC97 support.
 */

#include <linux/init.h>
#include <linux/slab.h>
#include <linux/kernel.h>
#include <linux/device.h>
#include <linux/module.h>
#include <sound/core.h>
#include <sound/pcm.h>
#include <sound/ac97_codec.h>
#include <sound/initval.h>
#include <sound/soc.h>

static int ac97_prepare(struct snd_pcm_substream *substream,
            struct snd_soc_dai *dai)
{
    struct snd_soc_codec *codec = dai->codec;

    int reg = (substream->stream == SNDRV_PCM_STREAM_PLAYBACK) ?
          AC97_PCM_FRONT_DAC_RATE : AC97_PCM_LR_ADC_RATE;
    return snd_ac97_set_rate(codec->ac97, reg, substream->runtime->rate);
}

#define STD_AC97_RATES (SNDRV_PCM_RATE_8000 | SNDRV_PCM_RATE_11025 |\
        SNDRV_PCM_RATE_22050 | SNDRV_PCM_RATE_44100 |\
        SNDRV_PCM_RATE_48000)

static const struct snd_soc_dai_ops ac97_dai_ops = {
    .prepare    = ac97_prepare,
};

static struct snd_soc_dai_driver ac97_dai = {
    .name = "ac97-hifi",
    .ac97_control = 1,
    .playback = {
        .stream_name = "AC97 Playback",
        .channels_min = 1,
        .channels_max = 2,
        .rates = STD_AC97_RATES,
        .formats = SND_SOC_STD_AC97_FMTS,},
    .capture = {
        .stream_name = "AC97 Capture",
        .channels_min = 1,
        .channels_max = 2,
        .rates = STD_AC97_RATES,
        .formats = SND_SOC_STD_AC97_FMTS,},
    .ops = &ac97_dai_ops,
};

static unsigned int ac97_read(struct snd_soc_codec *codec,
    unsigned int reg)
{
    return soc_ac97_ops.read(codec->ac97, reg);
}

static int ac97_write(struct snd_soc_codec *codec, unsigned int reg,
    unsigned int val)
{
    soc_ac97_ops.write(codec->ac97, reg, val);
    return 0;
}

static int ac97_soc_probe(struct snd_soc_codec *codec)
{
    struct snd_ac97_bus *ac97_bus;
    struct snd_ac97_template ac97_template;
    int ret;

    /* add codec as bus device for standard ac97 */
    ret = snd_ac97_bus(codec->card->snd_card, 0, &soc_ac97_ops, NULL, &ac97_bus);
    if (ret < 0)
        return ret;

    memset(&ac97_template, 0, sizeof(struct snd_ac97_template));
    ret = snd_ac97_mixer(ac97_bus, &ac97_template, &codec->ac97);
    if (ret < 0)
        return ret;

    return 0;
}

#ifdef CONFIG_PM
static int ac97_soc_suspend(struct snd_soc_codec *codec)
{
    snd_ac97_suspend(codec->ac97);

    return 0;
}

static int ac97_soc_resume(struct snd_soc_codec *codec)
{
    snd_ac97_resume(codec->ac97);

    return 0;
}
#else
#define ac97_soc_suspend NULL
#define ac97_soc_resume NULL
#endif

static struct snd_soc_codec_driver soc_codec_dev_ac97 = {
    .write =    ac97_write,
    .read =     ac97_read,
    .probe =    ac97_soc_probe,
    .suspend =  ac97_soc_suspend,
    .resume =   ac97_soc_resume,
};

static __devinit int ac97_probe(struct platform_device *pdev)
{
    return snd_soc_register_codec(&pdev->dev,
            &soc_codec_dev_ac97, &ac97_dai, 1);
}

static int __devexit ac97_remove(struct platform_device *pdev)
{
    snd_soc_unregister_codec(&pdev->dev);
    return 0;
}

static struct platform_driver ac97_codec_driver = {
    .driver = {
        .name = "ac97-codec",
        .owner = THIS_MODULE,
    },

    .probe = ac97_probe,
    .remove = __devexit_p(ac97_remove),
};

module_platform_driver(ac97_codec_driver);

MODULE_DESCRIPTION("Soc Generic AC97 driver");
MODULE_AUTHOR("Liam Girdwood");
MODULE_LICENSE("GPL");
MODULE_ALIAS("platform:ac97-codec");