xref: /linux/sound/soc/codecs/spdif_transmitter.c (revision e9f0878c4b2004ac19581274c1ae4c61ae3ca70e)
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 			SNDRV_PCM_FMTBIT_S32_LE)
32 
33 static const struct snd_soc_dapm_widget dit_widgets[] = {
34 	SND_SOC_DAPM_OUTPUT("spdif-out"),
35 };
36 
37 static const struct snd_soc_dapm_route dit_routes[] = {
38 	{ "spdif-out", NULL, "Playback" },
39 };
40 
41 static struct snd_soc_component_driver soc_codec_spdif_dit = {
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 	.idle_bias_on		= 1,
47 	.use_pmdown_time	= 1,
48 	.endianness		= 1,
49 	.non_legacy_dai_naming	= 1,
50 };
51 
52 static struct snd_soc_dai_driver dit_stub_dai = {
53 	.name		= "dit-hifi",
54 	.playback 	= {
55 		.stream_name	= "Playback",
56 		.channels_min	= 1,
57 		.channels_max	= 384,
58 		.rates		= STUB_RATES,
59 		.formats	= STUB_FORMATS,
60 	},
61 };
62 
63 static int spdif_dit_probe(struct platform_device *pdev)
64 {
65 	return devm_snd_soc_register_component(&pdev->dev,
66 			&soc_codec_spdif_dit,
67 			&dit_stub_dai, 1);
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 	.driver		= {
81 		.name	= DRV_NAME,
82 		.of_match_table = of_match_ptr(spdif_dit_dt_ids),
83 	},
84 };
85 
86 module_platform_driver(spdif_dit_driver);
87 
88 MODULE_AUTHOR("Steve Chen <schen@mvista.com>");
89 MODULE_DESCRIPTION("SPDIF dummy codec driver");
90 MODULE_LICENSE("GPL");
91 MODULE_ALIAS("platform:" DRV_NAME);
92