sound/soc/codecs/spdif_transmitter.c

   1 /*
   2  * ALSA SoC SPDIF DIT driver
   3  *
   4  *  This driver is used by controllers which can operate in DIT (SPDI/F) where
   5  *  no codec is needed.  This file provides stub codec that can be used
   6  *  in these configurations. TI DaVinci Audio controller uses this driver.
   7  *
   8  * Author:      Steve Chen,  <schen@mvista.com>
   9  * Copyright:   (C) 2009 MontaVista Software, Inc., <source@mvista.com>
  10  * Copyright:   (C) 2009  Texas Instruments, India
  11  *
  12  * This program is free software; you can redistribute it and/or modify
  13  * it under the terms of the GNU General Public License version 2 as
  14  * published by the Free Software Foundation.
  15  */
  16
  17 #include <linux/module.h>
  18 #include <linux/moduleparam.h>
  19 #include <linux/slab.h>
  20 #include <sound/soc.h>
  21 #include <sound/pcm.h>
  22 #include <sound/initval.h>
  23 #include <linux/of.h>
  24
  25 #define DRV_NAME "spdif-dit"
  26
  27 #define STUB_RATES      SNDRV_PCM_RATE_8000_192000
  28 #define STUB_FORMATS    (SNDRV_PCM_FMTBIT_S16_LE | \
  29                         SNDRV_PCM_FMTBIT_S20_3LE | \
  30                         SNDRV_PCM_FMTBIT_S24_LE)
  31
  32 static const struct snd_soc_dapm_widget dit_widgets[] = {
  33         SND_SOC_DAPM_OUTPUT("spdif-out"),
  34 };
  35
  36 static const struct snd_soc_dapm_route dit_routes[] = {
  37         { "spdif-out", NULL, "Playback" },
  38 };
  39
  40 static struct snd_soc_codec_driver soc_codec_spdif_dit = {
  41         .dapm_widgets = dit_widgets,
  42         .num_dapm_widgets = ARRAY_SIZE(dit_widgets),
  43         .dapm_routes = dit_routes,
  44         .num_dapm_routes = ARRAY_SIZE(dit_routes),
  45 };
  46
  47 static struct snd_soc_dai_driver dit_stub_dai = {
  48         .name           = "dit-hifi",
  49         .playback       = {
  50                 .stream_name    = "Playback",
  51                 .channels_min   = 1,
  52                 .channels_max   = 384,
  53                 .rates          = STUB_RATES,
  54                 .formats        = STUB_FORMATS,
  55         },
  56 };
  57
  58 static int spdif_dit_probe(struct platform_device *pdev)
  59 {
  60         return snd_soc_register_codec(&pdev->dev, &soc_codec_spdif_dit,
  61                         &dit_stub_dai, 1);
  62 }
  63
  64 static int spdif_dit_remove(struct platform_device *pdev)
  65 {
  66         snd_soc_unregister_codec(&pdev->dev);
  67         return 0;
  68 }
  69
  70 #ifdef CONFIG_OF
  71 static const struct of_device_id spdif_dit_dt_ids[] = {
  72         { .compatible = "linux,spdif-dit", },
  73         { }
  74 };
  75 MODULE_DEVICE_TABLE(of, spdif_dit_dt_ids);
  76 #endif
  77
  78 static struct platform_driver spdif_dit_driver = {
  79         .probe          = spdif_dit_probe,
  80         .remove         = spdif_dit_remove,
  81         .driver         = {
  82                 .name   = DRV_NAME,
  83                 .of_match_table = of_match_ptr(spdif_dit_dt_ids),
  84         },
  85 };
  86
  87 module_platform_driver(spdif_dit_driver);
  88
  89 MODULE_AUTHOR("Steve Chen <schen@mvista.com>");
  90 MODULE_DESCRIPTION("SPDIF dummy codec driver");
  91 MODULE_LICENSE("GPL");
  92 MODULE_ALIAS("platform:" DRV_NAME);