xref: /linux/sound/soc/soc-utils.c (revision b889fcf63cb62e7fdb7816565e28f44dbe4a76a5)
1 /*
2  * soc-util.c  --  ALSA SoC Audio Layer utility functions
3  *
4  * Copyright 2009 Wolfson Microelectronics PLC.
5  *
6  * Author: Mark Brown <broonie@opensource.wolfsonmicro.com>
7  *         Liam Girdwood <lrg@slimlogic.co.uk>
8  *
9  *
10  *  This program is free software; you can redistribute  it and/or modify it
11  *  under  the terms of  the GNU General  Public License as published by the
12  *  Free Software Foundation;  either version 2 of the  License, or (at your
13  *  option) any later version.
14  */
15 
16 #include <linux/platform_device.h>
17 #include <linux/export.h>
18 #include <sound/core.h>
19 #include <sound/pcm.h>
20 #include <sound/pcm_params.h>
21 #include <sound/soc.h>
22 
23 int snd_soc_calc_frame_size(int sample_size, int channels, int tdm_slots)
24 {
25 	return sample_size * channels * tdm_slots;
26 }
27 EXPORT_SYMBOL_GPL(snd_soc_calc_frame_size);
28 
29 int snd_soc_params_to_frame_size(struct snd_pcm_hw_params *params)
30 {
31 	int sample_size;
32 
33 	sample_size = snd_pcm_format_width(params_format(params));
34 	if (sample_size < 0)
35 		return sample_size;
36 
37 	return snd_soc_calc_frame_size(sample_size, params_channels(params),
38 				       1);
39 }
40 EXPORT_SYMBOL_GPL(snd_soc_params_to_frame_size);
41 
42 int snd_soc_calc_bclk(int fs, int sample_size, int channels, int tdm_slots)
43 {
44 	return fs * snd_soc_calc_frame_size(sample_size, channels, tdm_slots);
45 }
46 EXPORT_SYMBOL_GPL(snd_soc_calc_bclk);
47 
48 int snd_soc_params_to_bclk(struct snd_pcm_hw_params *params)
49 {
50 	int ret;
51 
52 	ret = snd_soc_params_to_frame_size(params);
53 
54 	if (ret > 0)
55 		return ret * params_rate(params);
56 	else
57 		return ret;
58 }
59 EXPORT_SYMBOL_GPL(snd_soc_params_to_bclk);
60 
61 static const struct snd_pcm_hardware dummy_dma_hardware = {
62 	.formats		= 0xffffffff,
63 	.channels_min		= 1,
64 	.channels_max		= UINT_MAX,
65 
66 	/* Random values to keep userspace happy when checking constraints */
67 	.info			= SNDRV_PCM_INFO_INTERLEAVED |
68 				  SNDRV_PCM_INFO_BLOCK_TRANSFER,
69 	.buffer_bytes_max	= 128*1024,
70 	.period_bytes_min	= PAGE_SIZE,
71 	.period_bytes_max	= PAGE_SIZE*2,
72 	.periods_min		= 2,
73 	.periods_max		= 128,
74 };
75 
76 static int dummy_dma_open(struct snd_pcm_substream *substream)
77 {
78 	snd_soc_set_runtime_hwparams(substream, &dummy_dma_hardware);
79 
80 	return 0;
81 }
82 
83 static struct snd_pcm_ops dummy_dma_ops = {
84 	.open		= dummy_dma_open,
85 	.ioctl		= snd_pcm_lib_ioctl,
86 };
87 
88 static struct snd_soc_platform_driver dummy_platform = {
89 	.ops = &dummy_dma_ops,
90 };
91 
92 static struct snd_soc_codec_driver dummy_codec;
93 static struct snd_soc_dai_driver dummy_dai = {
94 	.name = "snd-soc-dummy-dai",
95 };
96 
97 static int snd_soc_dummy_probe(struct platform_device *pdev)
98 {
99 	int ret;
100 
101 	ret = snd_soc_register_codec(&pdev->dev, &dummy_codec, &dummy_dai, 1);
102 	if (ret < 0)
103 		return ret;
104 
105 	ret = snd_soc_register_platform(&pdev->dev, &dummy_platform);
106 	if (ret < 0) {
107 		snd_soc_unregister_codec(&pdev->dev);
108 		return ret;
109 	}
110 
111 	return ret;
112 }
113 
114 static int snd_soc_dummy_remove(struct platform_device *pdev)
115 {
116 	snd_soc_unregister_platform(&pdev->dev);
117 	snd_soc_unregister_codec(&pdev->dev);
118 
119 	return 0;
120 }
121 
122 static struct platform_driver soc_dummy_driver = {
123 	.driver = {
124 		.name = "snd-soc-dummy",
125 		.owner = THIS_MODULE,
126 	},
127 	.probe = snd_soc_dummy_probe,
128 	.remove = snd_soc_dummy_remove,
129 };
130 
131 static struct platform_device *soc_dummy_dev;
132 
133 int __init snd_soc_util_init(void)
134 {
135 	int ret;
136 
137 	soc_dummy_dev = platform_device_alloc("snd-soc-dummy", -1);
138 	if (!soc_dummy_dev)
139 		return -ENOMEM;
140 
141 	ret = platform_device_add(soc_dummy_dev);
142 	if (ret != 0) {
143 		platform_device_put(soc_dummy_dev);
144 		return ret;
145 	}
146 
147 	ret = platform_driver_register(&soc_dummy_driver);
148 	if (ret != 0)
149 		platform_device_unregister(soc_dummy_dev);
150 
151 	return ret;
152 }
153 
154 void __exit snd_soc_util_exit(void)
155 {
156 	platform_device_unregister(soc_dummy_dev);
157 	platform_driver_unregister(&soc_dummy_driver);
158 }
159