soc/codecs/spdif_transmitter.c

0001 // SPDX-License-Identifier: GPL-2.0-only
0002 /*
0003  * ALSA SoC SPDIF DIT driver
0004  *
0005  *  This driver is used by controllers which can operate in DIT (SPDI/F) where
0006  *  no codec is needed.  This file provides stub codec that can be used
0007  *  in these configurations. TI DaVinci Audio controller uses this driver.
0008  *
0009  * Author:      Steve Chen,  <schen@mvista.com>
0010  * Copyright:   (C) 2009 MontaVista Software, Inc., <source@mvista.com>
0011  * Copyright:   (C) 2009  Texas Instruments, India
0012  */
0013
0014 #include <linux/module.h>
0015 #include <linux/moduleparam.h>
0016 #include <linux/slab.h>
0017 #include <sound/soc.h>
0018 #include <sound/pcm.h>
0019 #include <sound/initval.h>
0020 #include <linux/of.h>
0021
0022 #define DRV_NAME "spdif-dit"
0023
0024 #define STUB_RATES  SNDRV_PCM_RATE_8000_192000
0025 #define STUB_FORMATS    (SNDRV_PCM_FMTBIT_S16_LE | \
0026             SNDRV_PCM_FMTBIT_S20_3LE | \
0027             SNDRV_PCM_FMTBIT_S24_LE  | \
0028             SNDRV_PCM_FMTBIT_S32_LE)
0029
0030 static const struct snd_soc_dapm_widget dit_widgets[] = {
0031     SND_SOC_DAPM_OUTPUT("spdif-out"),
0032 };
0033
0034 static const struct snd_soc_dapm_route dit_routes[] = {
0035     { "spdif-out", NULL, "Playback" },
0036 };
0037
0038 static struct snd_soc_component_driver soc_codec_spdif_dit = {
0039     .dapm_widgets       = dit_widgets,
0040     .num_dapm_widgets   = ARRAY_SIZE(dit_widgets),
0041     .dapm_routes        = dit_routes,
0042     .num_dapm_routes    = ARRAY_SIZE(dit_routes),
0043     .idle_bias_on       = 1,
0044     .use_pmdown_time    = 1,
0045     .endianness     = 1,
0046 };
0047
0048 static struct snd_soc_dai_driver dit_stub_dai = {
0049     .name       = "dit-hifi",
0050     .playback   = {
0051         .stream_name    = "Playback",
0052         .channels_min   = 1,
0053         .channels_max   = 384,
0054         .rates      = STUB_RATES,
0055         .formats    = STUB_FORMATS,
0056     },
0057 };
0058
0059 static int spdif_dit_probe(struct platform_device *pdev)
0060 {
0061     return devm_snd_soc_register_component(&pdev->dev,
0062             &soc_codec_spdif_dit,
0063             &dit_stub_dai, 1);
0064 }
0065
0066 #ifdef CONFIG_OF
0067 static const struct of_device_id spdif_dit_dt_ids[] = {
0068     { .compatible = "linux,spdif-dit", },
0069     { }
0070 };
0071 MODULE_DEVICE_TABLE(of, spdif_dit_dt_ids);
0072 #endif
0073
0074 static struct platform_driver spdif_dit_driver = {
0075     .probe      = spdif_dit_probe,
0076     .driver     = {
0077         .name   = DRV_NAME,
0078         .of_match_table = of_match_ptr(spdif_dit_dt_ids),
0079     },
0080 };
0081
0082 module_platform_driver(spdif_dit_driver);
0083
0084 MODULE_AUTHOR("Steve Chen <schen@mvista.com>");
0085 MODULE_DESCRIPTION("SPDIF dummy codec driver");
0086 MODULE_LICENSE("GPL");
0087 MODULE_ALIAS("platform:" DRV_NAME);