xref: /linux/sound/soc/codecs/spdif_transmitter.c (revision e0bf6c5ca2d3281f231c5f0c9bf145e9513644de)
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);
93