1 // SPDX-License-Identifier: GPL-2.0+
3 // soc-util.c -- ALSA SoC Audio Layer utility functions
5 // Copyright 2009 Wolfson Microelectronics PLC.
7 // Author: Mark Brown <broonie@opensource.wolfsonmicro.com>
8 // Liam Girdwood <lrg@slimlogic.co.uk>
10 #include <linux/platform_device.h>
11 #include <linux/export.h>
12 #include <sound/core.h>
13 #include <sound/pcm.h>
14 #include <sound/pcm_params.h>
15 #include <sound/soc.h>
17 int snd_soc_calc_frame_size(int sample_size, int channels, int tdm_slots)
19 return sample_size * channels * tdm_slots;
21 EXPORT_SYMBOL_GPL(snd_soc_calc_frame_size);
23 int snd_soc_params_to_frame_size(struct snd_pcm_hw_params *params)
27 sample_size = snd_pcm_format_width(params_format(params));
31 return snd_soc_calc_frame_size(sample_size, params_channels(params),
34 EXPORT_SYMBOL_GPL(snd_soc_params_to_frame_size);
36 int snd_soc_calc_bclk(int fs, int sample_size, int channels, int tdm_slots)
38 return fs * snd_soc_calc_frame_size(sample_size, channels, tdm_slots);
40 EXPORT_SYMBOL_GPL(snd_soc_calc_bclk);
42 int snd_soc_params_to_bclk(struct snd_pcm_hw_params *params)
46 ret = snd_soc_params_to_frame_size(params);
49 return ret * params_rate(params);
53 EXPORT_SYMBOL_GPL(snd_soc_params_to_bclk);
55 static const struct snd_pcm_hardware dummy_dma_hardware = {
56 /* Random values to keep userspace happy when checking constraints */
57 .info = SNDRV_PCM_INFO_INTERLEAVED |
58 SNDRV_PCM_INFO_BLOCK_TRANSFER,
59 .buffer_bytes_max = 128*1024,
60 .period_bytes_min = PAGE_SIZE,
61 .period_bytes_max = PAGE_SIZE*2,
66 static int dummy_dma_open(struct snd_soc_component *component,
67 struct snd_pcm_substream *substream)
69 struct snd_soc_pcm_runtime *rtd = asoc_substream_to_rtd(substream);
71 /* BE's dont need dummy params */
72 if (!rtd->dai_link->no_pcm)
73 snd_soc_set_runtime_hwparams(substream, &dummy_dma_hardware);
78 static const struct snd_soc_component_driver dummy_platform = {
79 .open = dummy_dma_open,
82 static const struct snd_soc_component_driver dummy_codec = {
86 .non_legacy_dai_naming = 1,
89 #define STUB_RATES SNDRV_PCM_RATE_8000_384000
90 #define STUB_FORMATS (SNDRV_PCM_FMTBIT_S8 | \
91 SNDRV_PCM_FMTBIT_U8 | \
92 SNDRV_PCM_FMTBIT_S16_LE | \
93 SNDRV_PCM_FMTBIT_U16_LE | \
94 SNDRV_PCM_FMTBIT_S24_LE | \
95 SNDRV_PCM_FMTBIT_S24_3LE | \
96 SNDRV_PCM_FMTBIT_U24_LE | \
97 SNDRV_PCM_FMTBIT_S32_LE | \
98 SNDRV_PCM_FMTBIT_U32_LE | \
99 SNDRV_PCM_FMTBIT_IEC958_SUBFRAME_LE)
101 * The dummy CODEC is only meant to be used in situations where there is no
104 * If there is actual hardware even if it does not have a control bus
105 * the hardware will still have constraints like supported samplerates, etc.
106 * which should be modelled. And the data flow graph also should be modelled
109 static struct snd_soc_dai_driver dummy_dai = {
110 .name = "snd-soc-dummy-dai",
112 .stream_name = "Playback",
116 .formats = STUB_FORMATS,
119 .stream_name = "Capture",
123 .formats = STUB_FORMATS,
127 int snd_soc_dai_is_dummy(struct snd_soc_dai *dai)
129 if (dai->driver == &dummy_dai)
134 static int snd_soc_dummy_probe(struct platform_device *pdev)
138 ret = devm_snd_soc_register_component(&pdev->dev,
139 &dummy_codec, &dummy_dai, 1);
143 ret = devm_snd_soc_register_component(&pdev->dev, &dummy_platform,
149 static struct platform_driver soc_dummy_driver = {
151 .name = "snd-soc-dummy",
153 .probe = snd_soc_dummy_probe,
156 static struct platform_device *soc_dummy_dev;
158 int __init snd_soc_util_init(void)
163 platform_device_register_simple("snd-soc-dummy", -1, NULL, 0);
164 if (IS_ERR(soc_dummy_dev))
165 return PTR_ERR(soc_dummy_dev);
167 ret = platform_driver_register(&soc_dummy_driver);
169 platform_device_unregister(soc_dummy_dev);
174 void __exit snd_soc_util_exit(void)
176 platform_driver_unregister(&soc_dummy_driver);
177 platform_device_unregister(soc_dummy_dev);