xref: /openbmc/linux/sound/soc/soc-utils.c (revision 6355592e)
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_pcm_substream *substream)
67 {
68 	struct snd_soc_pcm_runtime *rtd = substream->private_data;
69 
70 	/* BE's dont need dummy params */
71 	if (!rtd->dai_link->no_pcm)
72 		snd_soc_set_runtime_hwparams(substream, &dummy_dma_hardware);
73 
74 	return 0;
75 }
76 
77 static const struct snd_pcm_ops snd_dummy_dma_ops = {
78 	.open		= dummy_dma_open,
79 	.ioctl		= snd_pcm_lib_ioctl,
80 };
81 
82 static const struct snd_soc_component_driver dummy_platform = {
83 	.ops = &snd_dummy_dma_ops,
84 };
85 
86 static const struct snd_soc_component_driver dummy_codec = {
87 	.idle_bias_on		= 1,
88 	.use_pmdown_time	= 1,
89 	.endianness		= 1,
90 	.non_legacy_dai_naming	= 1,
91 };
92 
93 #define STUB_RATES	SNDRV_PCM_RATE_8000_192000
94 #define STUB_FORMATS	(SNDRV_PCM_FMTBIT_S8 | \
95 			SNDRV_PCM_FMTBIT_U8 | \
96 			SNDRV_PCM_FMTBIT_S16_LE | \
97 			SNDRV_PCM_FMTBIT_U16_LE | \
98 			SNDRV_PCM_FMTBIT_S24_LE | \
99 			SNDRV_PCM_FMTBIT_U24_LE | \
100 			SNDRV_PCM_FMTBIT_S32_LE | \
101 			SNDRV_PCM_FMTBIT_U32_LE | \
102 			SNDRV_PCM_FMTBIT_IEC958_SUBFRAME_LE)
103 /*
104  * The dummy CODEC is only meant to be used in situations where there is no
105  * actual hardware.
106  *
107  * If there is actual hardware even if it does not have a control bus
108  * the hardware will still have constraints like supported samplerates, etc.
109  * which should be modelled. And the data flow graph also should be modelled
110  * using DAPM.
111  */
112 static struct snd_soc_dai_driver dummy_dai = {
113 	.name = "snd-soc-dummy-dai",
114 	.playback = {
115 		.stream_name	= "Playback",
116 		.channels_min	= 1,
117 		.channels_max	= 384,
118 		.rates		= STUB_RATES,
119 		.formats	= STUB_FORMATS,
120 	},
121 	.capture = {
122 		.stream_name	= "Capture",
123 		.channels_min	= 1,
124 		.channels_max	= 384,
125 		.rates = STUB_RATES,
126 		.formats = STUB_FORMATS,
127 	 },
128 };
129 
130 int snd_soc_dai_is_dummy(struct snd_soc_dai *dai)
131 {
132 	if (dai->driver == &dummy_dai)
133 		return 1;
134 	return 0;
135 }
136 
137 static int snd_soc_dummy_probe(struct platform_device *pdev)
138 {
139 	int ret;
140 
141 	ret = devm_snd_soc_register_component(&pdev->dev,
142 					      &dummy_codec, &dummy_dai, 1);
143 	if (ret < 0)
144 		return ret;
145 
146 	ret = devm_snd_soc_register_component(&pdev->dev, &dummy_platform,
147 					      NULL, 0);
148 
149 	return ret;
150 }
151 
152 static struct platform_driver soc_dummy_driver = {
153 	.driver = {
154 		.name = "snd-soc-dummy",
155 	},
156 	.probe = snd_soc_dummy_probe,
157 };
158 
159 static struct platform_device *soc_dummy_dev;
160 
161 int __init snd_soc_util_init(void)
162 {
163 	int ret;
164 
165 	soc_dummy_dev =
166 		platform_device_register_simple("snd-soc-dummy", -1, NULL, 0);
167 	if (IS_ERR(soc_dummy_dev))
168 		return PTR_ERR(soc_dummy_dev);
169 
170 	ret = platform_driver_register(&soc_dummy_driver);
171 	if (ret != 0)
172 		platform_device_unregister(soc_dummy_dev);
173 
174 	return ret;
175 }
176 
177 void __exit snd_soc_util_exit(void)
178 {
179 	platform_driver_unregister(&soc_dummy_driver);
180 	platform_device_unregister(soc_dummy_dev);
181 }
182