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 
spdif_dit_probe(struct platform_device * pdev)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);
88