linux/sound/soc/soc-utils.c
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   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
  23int snd_soc_calc_frame_size(int sample_size, int channels, int tdm_slots)
  24{
  25        return sample_size * channels * tdm_slots;
  26}
  27EXPORT_SYMBOL_GPL(snd_soc_calc_frame_size);
  28
  29int 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}
  40EXPORT_SYMBOL_GPL(snd_soc_params_to_frame_size);
  41
  42int 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}
  46EXPORT_SYMBOL_GPL(snd_soc_calc_bclk);
  47
  48int 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}
  59EXPORT_SYMBOL_GPL(snd_soc_params_to_bclk);
  60
  61static const struct snd_pcm_hardware dummy_dma_hardware = {
  62        /* Random values to keep userspace happy when checking constraints */
  63        .info                   = SNDRV_PCM_INFO_INTERLEAVED |
  64                                  SNDRV_PCM_INFO_BLOCK_TRANSFER,
  65        .buffer_bytes_max       = 128*1024,
  66        .period_bytes_min       = PAGE_SIZE,
  67        .period_bytes_max       = PAGE_SIZE*2,
  68        .periods_min            = 2,
  69        .periods_max            = 128,
  70};
  71
  72static int dummy_dma_open(struct snd_pcm_substream *substream)
  73{
  74        struct snd_soc_pcm_runtime *rtd = substream->private_data;
  75
  76        /* BE's dont need dummy params */
  77        if (!rtd->dai_link->no_pcm)
  78                snd_soc_set_runtime_hwparams(substream, &dummy_dma_hardware);
  79
  80        return 0;
  81}
  82
  83static const struct snd_pcm_ops dummy_dma_ops = {
  84        .open           = dummy_dma_open,
  85        .ioctl          = snd_pcm_lib_ioctl,
  86};
  87
  88static struct snd_soc_platform_driver dummy_platform = {
  89        .ops = &dummy_dma_ops,
  90};
  91
  92static struct snd_soc_codec_driver dummy_codec;
  93
  94#define STUB_RATES      SNDRV_PCM_RATE_8000_192000
  95#define STUB_FORMATS    (SNDRV_PCM_FMTBIT_S8 | \
  96                        SNDRV_PCM_FMTBIT_U8 | \
  97                        SNDRV_PCM_FMTBIT_S16_LE | \
  98                        SNDRV_PCM_FMTBIT_U16_LE | \
  99                        SNDRV_PCM_FMTBIT_S24_LE | \
 100                        SNDRV_PCM_FMTBIT_U24_LE | \
 101                        SNDRV_PCM_FMTBIT_S32_LE | \
 102                        SNDRV_PCM_FMTBIT_U32_LE | \
 103                        SNDRV_PCM_FMTBIT_IEC958_SUBFRAME_LE)
 104/*
 105 * The dummy CODEC is only meant to be used in situations where there is no
 106 * actual hardware.
 107 *
 108 * If there is actual hardware even if it does not have a control bus
 109 * the hardware will still have constraints like supported samplerates, etc.
 110 * which should be modelled. And the data flow graph also should be modelled
 111 * using DAPM.
 112 */
 113static struct snd_soc_dai_driver dummy_dai = {
 114        .name = "snd-soc-dummy-dai",
 115        .playback = {
 116                .stream_name    = "Playback",
 117                .channels_min   = 1,
 118                .channels_max   = 384,
 119                .rates          = STUB_RATES,
 120                .formats        = STUB_FORMATS,
 121        },
 122        .capture = {
 123                .stream_name    = "Capture",
 124                .channels_min   = 1,
 125                .channels_max   = 384,
 126                .rates = STUB_RATES,
 127                .formats = STUB_FORMATS,
 128         },
 129};
 130
 131int snd_soc_dai_is_dummy(struct snd_soc_dai *dai)
 132{
 133        if (dai->driver == &dummy_dai)
 134                return 1;
 135        return 0;
 136}
 137
 138static int snd_soc_dummy_probe(struct platform_device *pdev)
 139{
 140        int ret;
 141
 142        ret = snd_soc_register_codec(&pdev->dev, &dummy_codec, &dummy_dai, 1);
 143        if (ret < 0)
 144                return ret;
 145
 146        ret = snd_soc_register_platform(&pdev->dev, &dummy_platform);
 147        if (ret < 0) {
 148                snd_soc_unregister_codec(&pdev->dev);
 149                return ret;
 150        }
 151
 152        return ret;
 153}
 154
 155static int snd_soc_dummy_remove(struct platform_device *pdev)
 156{
 157        snd_soc_unregister_platform(&pdev->dev);
 158        snd_soc_unregister_codec(&pdev->dev);
 159
 160        return 0;
 161}
 162
 163static struct platform_driver soc_dummy_driver = {
 164        .driver = {
 165                .name = "snd-soc-dummy",
 166        },
 167        .probe = snd_soc_dummy_probe,
 168        .remove = snd_soc_dummy_remove,
 169};
 170
 171static struct platform_device *soc_dummy_dev;
 172
 173int __init snd_soc_util_init(void)
 174{
 175        int ret;
 176
 177        soc_dummy_dev =
 178                platform_device_register_simple("snd-soc-dummy", -1, NULL, 0);
 179        if (IS_ERR(soc_dummy_dev))
 180                return PTR_ERR(soc_dummy_dev);
 181
 182        ret = platform_driver_register(&soc_dummy_driver);
 183        if (ret != 0)
 184                platform_device_unregister(soc_dummy_dev);
 185
 186        return ret;
 187}
 188
 189void __exit snd_soc_util_exit(void)
 190{
 191        platform_device_unregister(soc_dummy_dev);
 192        platform_driver_unregister(&soc_dummy_driver);
 193}
 194