1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  * ALSA SoC SPDIF DIR (Digital Interface Reciever) driver
4  *
5  * Based on ALSA SoC SPDIF DIT driver
6  *
7  *  This driver is used by controllers which can operate in DIR (SPDI/F) where
8  *  no codec is needed.  This file provides stub codec that can be used
9  *  in these configurations. SPEAr SPDIF IN Audio controller uses this driver.
10  *
11  * Author:      Vipin Kumar,  <vipin.kumar@st.com>
12  * Copyright:   (C) 2012  ST Microelectronics
13  */
14 
15 #include <linux/module.h>
16 #include <linux/moduleparam.h>
17 #include <linux/slab.h>
18 #include <sound/soc.h>
19 #include <sound/pcm.h>
20 #include <sound/initval.h>
21 #include <linux/of.h>
22 
23 static const struct snd_soc_dapm_widget dir_widgets[] = {
24 	SND_SOC_DAPM_INPUT("spdif-in"),
25 };
26 
27 static const struct snd_soc_dapm_route dir_routes[] = {
28 	{ "Capture", NULL, "spdif-in" },
29 };
30 
31 #define STUB_RATES	SNDRV_PCM_RATE_8000_192000
32 #define STUB_FORMATS	(SNDRV_PCM_FMTBIT_S16_LE | \
33 			SNDRV_PCM_FMTBIT_S20_3LE | \
34 			SNDRV_PCM_FMTBIT_S24_LE  | \
35 			SNDRV_PCM_FMTBIT_S32_LE | \
36 			SNDRV_PCM_FMTBIT_IEC958_SUBFRAME_LE)
37 
38 static struct snd_soc_component_driver soc_codec_spdif_dir = {
39 	.dapm_widgets		= dir_widgets,
40 	.num_dapm_widgets	= ARRAY_SIZE(dir_widgets),
41 	.dapm_routes		= dir_routes,
42 	.num_dapm_routes	= ARRAY_SIZE(dir_routes),
43 	.idle_bias_on		= 1,
44 	.use_pmdown_time	= 1,
45 	.endianness		= 1,
46 };
47 
48 static struct snd_soc_dai_driver dir_stub_dai = {
49 	.name		= "dir-hifi",
50 	.capture	= {
51 		.stream_name	= "Capture",
52 		.channels_min	= 1,
53 		.channels_max	= 384,
54 		.rates		= STUB_RATES,
55 		.formats	= STUB_FORMATS,
56 	},
57 };
58 
59 static int spdif_dir_probe(struct platform_device *pdev)
60 {
61 	return devm_snd_soc_register_component(&pdev->dev,
62 			&soc_codec_spdif_dir,
63 			&dir_stub_dai, 1);
64 }
65 
66 #ifdef CONFIG_OF
67 static const struct of_device_id spdif_dir_dt_ids[] = {
68 	{ .compatible = "linux,spdif-dir", },
69 	{ }
70 };
71 MODULE_DEVICE_TABLE(of, spdif_dir_dt_ids);
72 #endif
73 
74 static struct platform_driver spdif_dir_driver = {
75 	.probe		= spdif_dir_probe,
76 	.driver		= {
77 		.name	= "spdif-dir",
78 		.of_match_table = of_match_ptr(spdif_dir_dt_ids),
79 	},
80 };
81 
82 module_platform_driver(spdif_dir_driver);
83 
84 MODULE_DESCRIPTION("ASoC SPDIF DIR driver");
85 MODULE_AUTHOR("Vipin Kumar <vipin.kumar@st.com>");
86 MODULE_LICENSE("GPL");
87