sound/soc/soc-utils.c

   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 __devinit int snd_soc_dummy_probe(struct platform_device *pdev)
  93 {
  94         return snd_soc_register_platform(&pdev->dev, &dummy_platform);
  95 }
  96
  97 static __devexit int snd_soc_dummy_remove(struct platform_device *pdev)
  98 {
  99         snd_soc_unregister_platform(&pdev->dev);
 100
 101         return 0;
 102 }
 103
 104 static struct platform_driver soc_dummy_driver = {
 105         .driver = {
 106                 .name = "snd-soc-dummy",
 107                 .owner = THIS_MODULE,
 108         },
 109         .probe = snd_soc_dummy_probe,
 110         .remove = __devexit_p(snd_soc_dummy_remove),
 111 };
 112
 113 static struct platform_device *soc_dummy_dev;
 114
 115 int __init snd_soc_util_init(void)
 116 {
 117         int ret;
 118
 119         soc_dummy_dev = platform_device_alloc("snd-soc-dummy", -1);
 120         if (!soc_dummy_dev)
 121                 return -ENOMEM;
 122
 123         ret = platform_device_add(soc_dummy_dev);
 124         if (ret != 0) {
 125                 platform_device_put(soc_dummy_dev);
 126                 return ret;
 127         }
 128
 129         ret = platform_driver_register(&soc_dummy_driver);
 130         if (ret != 0)
 131                 platform_device_unregister(soc_dummy_dev);
 132
 133         return ret;
 134 }
 135
 136 void __exit snd_soc_util_exit(void)
 137 {
 138         platform_device_unregister(soc_dummy_dev);
 139         platform_driver_unregister(&soc_dummy_driver);
 140 }