sound/soc/codecs/spdif_transmitter.c

   1 // SPDX-License-Identifier: GPL-2.0-only
   2 /*
   3  * ALSA SoC SPDIF DIT driver
   4  *
   5  *  This driver is used by controllers which can operate in DIT (SPDI/F) where
   6  *  no codec is needed.  This file provides stub codec that can be used
   7  *  in these configurations. TI DaVinci Audio controller uses this driver.
   8  *
   9  * Author:      Steve Chen,  <schen@mvista.com>
  10  * Copyright:   (C) 2009 MontaVista Software, Inc., <source@mvista.com>
  11  * Copyright:   (C) 2009  Texas Instruments, India
  12  */
  13
  14 #include <linux/module.h>
  15 #include <linux/moduleparam.h>
  16 #include <linux/slab.h>
  17 #include <sound/soc.h>
  18 #include <sound/pcm.h>
  19 #include <sound/initval.h>
  20 #include <linux/of.h>
  21
  22 #define DRV_NAME "spdif-dit"
  23
  24 #define STUB_RATES      SNDRV_PCM_RATE_8000_192000
  25 #define STUB_FORMATS    (SNDRV_PCM_FMTBIT_S16_LE | \
  26                         SNDRV_PCM_FMTBIT_S20_3LE | \
  27                         SNDRV_PCM_FMTBIT_S24_LE  | \
  28                         SNDRV_PCM_FMTBIT_S32_LE)
  29
  30 static const struct snd_soc_dapm_widget dit_widgets[] = {
  31         SND_SOC_DAPM_OUTPUT("spdif-out"),
  32 };
  33
  34 static const struct snd_soc_dapm_route dit_routes[] = {
  35         { "spdif-out", NULL, "Playback" },
  36 };
  37
  38 static struct snd_soc_component_driver soc_codec_spdif_dit = {
  39         .dapm_widgets           = dit_widgets,
  40         .num_dapm_widgets       = ARRAY_SIZE(dit_widgets),
  41         .dapm_routes            = dit_routes,
  42         .num_dapm_routes        = ARRAY_SIZE(dit_routes),
  43         .idle_bias_on           = 1,
  44         .use_pmdown_time        = 1,
  45         .endianness             = 1,
  46 };
  47
  48 static struct snd_soc_dai_driver dit_stub_dai = {
  49         .name           = "dit-hifi",
  50         .playback       = {
  51                 .stream_name    = "Playback",
  52                 .channels_min   = 1,
  53                 .channels_max   = 384,
  54                 .rates          = STUB_RATES,
  55                 .formats        = STUB_FORMATS,
  56         },
  57 };
  58
  59 static int spdif_dit_probe(struct platform_device *pdev)
  60 {
  61         return devm_snd_soc_register_component(&pdev->dev,
  62                         &soc_codec_spdif_dit,
  63                         &dit_stub_dai, 1);
  64 }
  65
  66 #ifdef CONFIG_OF
  67 static const struct of_device_id spdif_dit_dt_ids[] = {
  68         { .compatible = "linux,spdif-dit", },
  69         { }
  70 };
  71 MODULE_DEVICE_TABLE(of, spdif_dit_dt_ids);
  72 #endif
  73
  74 static struct platform_driver spdif_dit_driver = {
  75         .probe          = spdif_dit_probe,
  76         .driver         = {
  77                 .name   = DRV_NAME,
  78                 .of_match_table = of_match_ptr(spdif_dit_dt_ids),
  79         },
  80 };
  81
  82 module_platform_driver(spdif_dit_driver);
  83
  84 MODULE_AUTHOR("Steve Chen <schen@mvista.com>");
  85 MODULE_DESCRIPTION("SPDIF dummy codec driver");
  86 MODULE_LICENSE("GPL");
  87 MODULE_ALIAS("platform:" DRV_NAME);