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
30static const struct snd_soc_dapm_widget dit_widgets[] = {
31 SND_SOC_DAPM_OUTPUT("spdif-out"),
32};
33
34static const struct snd_soc_dapm_route dit_routes[] = {
35 { "spdif-out", NULL, "Playback" },
36};
37
38static 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
48static 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
59static int spdif_dit_probe(struct platform_device *pdev)
60{
61 return devm_snd_soc_register_component(dev: &pdev->dev,
62 component_driver: &soc_codec_spdif_dit,
63 dai_drv: &dit_stub_dai, num_dai: 1);
64}
65
66#ifdef CONFIG_OF
67static const struct of_device_id spdif_dit_dt_ids[] = {
68 { .compatible = "linux,spdif-dit", },
69 { }
70};
71MODULE_DEVICE_TABLE(of, spdif_dit_dt_ids);
72#endif
73
74static 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
82module_platform_driver(spdif_dit_driver);
83
84MODULE_AUTHOR("Steve Chen <schen@mvista.com>");
85MODULE_DESCRIPTION("SPDIF dummy codec driver");
86MODULE_LICENSE("GPL");
87MODULE_ALIAS("platform:" DRV_NAME);
88

source code of linux/sound/soc/codecs/spdif_transmitter.c