xref: /linux/sound/soc/soc-utils.c (revision b77e0ce62d63a761ffb7f7245a215a49f5921c2f)
1 // SPDX-License-Identifier: GPL-2.0+
2 //
3 // soc-util.c  --  ALSA SoC Audio Layer utility functions
4 //
5 // Copyright 2009 Wolfson Microelectronics PLC.
6 //
7 // Author: Mark Brown <broonie@opensource.wolfsonmicro.com>
8 //         Liam Girdwood <lrg@slimlogic.co.uk>
9 
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>
16 
17 int snd_soc_calc_frame_size(int sample_size, int channels, int tdm_slots)
18 {
19 	return sample_size * channels * tdm_slots;
20 }
21 EXPORT_SYMBOL_GPL(snd_soc_calc_frame_size);
22 
23 int snd_soc_params_to_frame_size(struct snd_pcm_hw_params *params)
24 {
25 	int sample_size;
26 
27 	sample_size = snd_pcm_format_width(params_format(params));
28 	if (sample_size < 0)
29 		return sample_size;
30 
31 	return snd_soc_calc_frame_size(sample_size, params_channels(params),
32 				       1);
33 }
34 EXPORT_SYMBOL_GPL(snd_soc_params_to_frame_size);
35 
36 int snd_soc_calc_bclk(int fs, int sample_size, int channels, int tdm_slots)
37 {
38 	return fs * snd_soc_calc_frame_size(sample_size, channels, tdm_slots);
39 }
40 EXPORT_SYMBOL_GPL(snd_soc_calc_bclk);
41 
42 int snd_soc_params_to_bclk(struct snd_pcm_hw_params *params)
43 {
44 	int ret;
45 
46 	ret = snd_soc_params_to_frame_size(params);
47 
48 	if (ret > 0)
49 		return ret * params_rate(params);
50 	else
51 		return ret;
52 }
53 EXPORT_SYMBOL_GPL(snd_soc_params_to_bclk);
54 
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,
62 	.periods_min		= 2,
63 	.periods_max		= 128,
64 };
65 
66 static int dummy_dma_open(struct snd_soc_component *component,
67 			  struct snd_pcm_substream *substream)
68 {
69 	struct snd_soc_pcm_runtime *rtd = asoc_substream_to_rtd(substream);
70 
71 	/* BE's dont need dummy params */
72 	if (!rtd->dai_link->no_pcm)
73 		snd_soc_set_runtime_hwparams(substream, &dummy_dma_hardware);
74 
75 	return 0;
76 }
77 
78 static const struct snd_soc_component_driver dummy_platform = {
79 	.open		= dummy_dma_open,
80 };
81 
82 static const struct snd_soc_component_driver dummy_codec = {
83 	.idle_bias_on		= 1,
84 	.use_pmdown_time	= 1,
85 	.endianness		= 1,
86 	.non_legacy_dai_naming	= 1,
87 };
88 
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)
100 /*
101  * The dummy CODEC is only meant to be used in situations where there is no
102  * actual hardware.
103  *
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
107  * using DAPM.
108  */
109 static struct snd_soc_dai_driver dummy_dai = {
110 	.name = "snd-soc-dummy-dai",
111 	.playback = {
112 		.stream_name	= "Playback",
113 		.channels_min	= 1,
114 		.channels_max	= 384,
115 		.rates		= STUB_RATES,
116 		.formats	= STUB_FORMATS,
117 	},
118 	.capture = {
119 		.stream_name	= "Capture",
120 		.channels_min	= 1,
121 		.channels_max	= 384,
122 		.rates = STUB_RATES,
123 		.formats = STUB_FORMATS,
124 	 },
125 };
126 
127 int snd_soc_dai_is_dummy(struct snd_soc_dai *dai)
128 {
129 	if (dai->driver == &dummy_dai)
130 		return 1;
131 	return 0;
132 }
133 
134 static int snd_soc_dummy_probe(struct platform_device *pdev)
135 {
136 	int ret;
137 
138 	ret = devm_snd_soc_register_component(&pdev->dev,
139 					      &dummy_codec, &dummy_dai, 1);
140 	if (ret < 0)
141 		return ret;
142 
143 	ret = devm_snd_soc_register_component(&pdev->dev, &dummy_platform,
144 					      NULL, 0);
145 
146 	return ret;
147 }
148 
149 static struct platform_driver soc_dummy_driver = {
150 	.driver = {
151 		.name = "snd-soc-dummy",
152 	},
153 	.probe = snd_soc_dummy_probe,
154 };
155 
156 static struct platform_device *soc_dummy_dev;
157 
158 int __init snd_soc_util_init(void)
159 {
160 	int ret;
161 
162 	soc_dummy_dev =
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);
166 
167 	ret = platform_driver_register(&soc_dummy_driver);
168 	if (ret != 0)
169 		platform_device_unregister(soc_dummy_dev);
170 
171 	return ret;
172 }
173 
174 void __exit snd_soc_util_exit(void)
175 {
176 	platform_driver_unregister(&soc_dummy_driver);
177 	platform_device_unregister(soc_dummy_dev);
178 }
179