xref: /linux/sound/soc/codecs/spdif_transmitter.c (revision e5c86679d5e864947a52fb31e45a425dea3e7fa9)
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 	.component_driver = {
42 		.dapm_widgets		= dit_widgets,
43 		.num_dapm_widgets	= ARRAY_SIZE(dit_widgets),
44 		.dapm_routes		= dit_routes,
45 		.num_dapm_routes	= ARRAY_SIZE(dit_routes),
46 	},
47 };
48 
49 static struct snd_soc_dai_driver dit_stub_dai = {
50 	.name		= "dit-hifi",
51 	.playback 	= {
52 		.stream_name	= "Playback",
53 		.channels_min	= 1,
54 		.channels_max	= 384,
55 		.rates		= STUB_RATES,
56 		.formats	= STUB_FORMATS,
57 	},
58 };
59 
60 static int spdif_dit_probe(struct platform_device *pdev)
61 {
62 	return snd_soc_register_codec(&pdev->dev, &soc_codec_spdif_dit,
63 			&dit_stub_dai, 1);
64 }
65 
66 static int spdif_dit_remove(struct platform_device *pdev)
67 {
68 	snd_soc_unregister_codec(&pdev->dev);
69 	return 0;
70 }
71 
72 #ifdef CONFIG_OF
73 static const struct of_device_id spdif_dit_dt_ids[] = {
74 	{ .compatible = "linux,spdif-dit", },
75 	{ }
76 };
77 MODULE_DEVICE_TABLE(of, spdif_dit_dt_ids);
78 #endif
79 
80 static struct platform_driver spdif_dit_driver = {
81 	.probe		= spdif_dit_probe,
82 	.remove		= spdif_dit_remove,
83 	.driver		= {
84 		.name	= DRV_NAME,
85 		.of_match_table = of_match_ptr(spdif_dit_dt_ids),
86 	},
87 };
88 
89 module_platform_driver(spdif_dit_driver);
90 
91 MODULE_AUTHOR("Steve Chen <schen@mvista.com>");
92 MODULE_DESCRIPTION("SPDIF dummy codec driver");
93 MODULE_LICENSE("GPL");
94 MODULE_ALIAS("platform:" DRV_NAME);
95