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ac97.c

/*
 * ac97.c  --  ALSA Soc AC97 codec support
 *
 * Copyright 2005 Wolfson Microelectronics PLC.
 * Author: Liam Girdwood
 *         liam.girdwood@wolfsonmicro.com or linux@wolfsonmicro.com
 *
 *  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.
 *
 *  Revision history
 *    17th Oct 2005   Initial version.
 *
 * Generic AC97 support.
 */

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

#define AC97_VERSION "0.6"

static int ac97_prepare(struct snd_pcm_substream *substream)
{
      struct snd_pcm_runtime *runtime = substream->runtime;
      struct snd_soc_pcm_runtime *rtd = substream->private_data;
      struct snd_soc_device *socdev = rtd->socdev;
      struct snd_soc_codec *codec = socdev->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, 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)

struct snd_soc_codec_dai ac97_dai = {
      .name = "AC97 HiFi",
      .type = SND_SOC_DAI_AC97,
      .playback = {
            .stream_name = "AC97 Playback",
            .channels_min = 1,
            .channels_max = 2,
            .rates = STD_AC97_RATES,
            .formats = SNDRV_PCM_FMTBIT_S16_LE,},
      .capture = {
            .stream_name = "AC97 Capture",
            .channels_min = 1,
            .channels_max = 2,
            .rates = STD_AC97_RATES,
            .formats = SNDRV_PCM_FMTBIT_S16_LE,},
      .ops = {
            .prepare = ac97_prepare,},
};
EXPORT_SYMBOL_GPL(ac97_dai);

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 platform_device *pdev)
{
      struct snd_soc_device *socdev = platform_get_drvdata(pdev);
      struct snd_soc_codec *codec;
      struct snd_ac97_bus *ac97_bus;
      struct snd_ac97_template ac97_template;
      int ret = 0;

      printk(KERN_INFO "AC97 SoC Audio Codec %s\n", AC97_VERSION);

      socdev->codec = kzalloc(sizeof(struct snd_soc_codec), GFP_KERNEL);
      if (socdev->codec == NULL)
            return -ENOMEM;
      codec = socdev->codec;
      mutex_init(&codec->mutex);

      codec->name = "AC97";
      codec->owner = THIS_MODULE;
      codec->dai = &ac97_dai;
      codec->num_dai = 1;
      codec->write = ac97_write;
      codec->read = ac97_read;
      INIT_LIST_HEAD(&codec->dapm_widgets);
      INIT_LIST_HEAD(&codec->dapm_paths);

      /* register pcms */
      ret = snd_soc_new_pcms(socdev, SNDRV_DEFAULT_IDX1, SNDRV_DEFAULT_STR1);
      if(ret < 0)
            goto err;

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

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

      ret = snd_soc_register_card(socdev);
      if (ret < 0)
            goto bus_err;
      return 0;

bus_err:
      snd_soc_free_pcms(socdev);

err:
      kfree(socdev->codec->reg_cache);
      kfree(socdev->codec);
      socdev->codec = NULL;
      return ret;
}

static int ac97_soc_remove(struct platform_device *pdev)
{
      struct snd_soc_device *socdev = platform_get_drvdata(pdev);
      struct snd_soc_codec *codec = socdev->codec;

      if(codec == NULL)
            return 0;

      snd_soc_free_pcms(socdev);
      kfree(socdev->codec->reg_cache);
      kfree(socdev->codec);

      return 0;
}

struct snd_soc_codec_device soc_codec_dev_ac97= {
      .probe =    ac97_soc_probe,
      .remove =   ac97_soc_remove,
};

EXPORT_SYMBOL_GPL(soc_codec_dev_ac97);

MODULE_DESCRIPTION("Soc Generic AC97 driver");
MODULE_AUTHOR("Liam Girdwood");
MODULE_LICENSE("GPL");

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