sound/soc/bcm/allo-piano-dac.c

   1 /*
   2  * ALSA ASoC Machine Driver for Allo Piano DAC
   3  *
   4  * Author:      Baswaraj K <jaikumar@cem-solutions.net>
   5  *              Copyright 2016
   6  *              based on code by Daniel Matuschek <info@crazy-audio.com>
   7  *              based on code by Florian Meier <florian.meier@koalo.de>
   8  *
   9  * This program is free software; you can redistribute it and/or
  10  * modify it under the terms of the GNU General Public License
  11  * version 2 as published by the Free Software Foundation.
  12  *
  13  * This program is distributed in the hope that it will be useful, but
  14  * WITHOUT ANY WARRANTY; without even the implied warranty of
  15  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  16  * General Public License for more details.
  17  */
  18
  19 #include <linux/module.h>
  20 #include <linux/platform_device.h>
  21
  22 #include <sound/core.h>
  23 #include <sound/pcm.h>
  24 #include <sound/pcm_params.h>
  25 #include <sound/soc.h>
  26
  27 static bool digital_gain_0db_limit = true;
  28
  29 static int snd_allo_piano_dac_init(struct snd_soc_pcm_runtime *rtd)
  30 {
  31         if (digital_gain_0db_limit) {
  32                 int ret;
  33                 struct snd_soc_card *card = rtd->card;
  34
  35                 ret = snd_soc_limit_volume(card, "Digital Playback Volume",
  36                                            207);
  37                 if (ret < 0)
  38                         dev_warn(card->dev, "Failed to set volume limit: %d\n",
  39                                  ret);
  40         }
  41
  42         return 0;
  43 }
  44
  45 SND_SOC_DAILINK_DEFS(allo_piano_dai,
  46         DAILINK_COMP_ARRAY(COMP_CPU("bcm2708-i2s.0")),
  47         DAILINK_COMP_ARRAY(COMP_CODEC("pcm512x.1-004c", "pcm512x-hifi")),
  48         DAILINK_COMP_ARRAY(COMP_PLATFORM("bcm2708-i2s.0")));
  49
  50 static struct snd_soc_dai_link snd_allo_piano_dac_dai[] = {
  51 {
  52         .name           = "Piano DAC",
  53         .stream_name    = "Piano DAC HiFi",
  54         .dai_fmt        = SND_SOC_DAIFMT_I2S |
  55                           SND_SOC_DAIFMT_NB_NF |
  56                           SND_SOC_DAIFMT_CBS_CFS,
  57         .init           = snd_allo_piano_dac_init,
  58         SND_SOC_DAILINK_REG(allo_piano_dai),
  59 },
  60 };
  61
  62 /* audio machine driver */
  63 static struct snd_soc_card snd_allo_piano_dac = {
  64         .name         = "PianoDAC",
  65         .owner        = THIS_MODULE,
  66         .dai_link     = snd_allo_piano_dac_dai,
  67         .num_links    = ARRAY_SIZE(snd_allo_piano_dac_dai),
  68 };
  69
  70 static int snd_allo_piano_dac_probe(struct platform_device *pdev)
  71 {
  72         int ret = 0;
  73
  74         snd_allo_piano_dac.dev = &pdev->dev;
  75
  76         if (pdev->dev.of_node) {
  77                 struct device_node *i2s_node;
  78                 struct snd_soc_dai_link *dai;
  79
  80                 dai = &snd_allo_piano_dac_dai[0];
  81                 i2s_node = of_parse_phandle(pdev->dev.of_node,
  82                                             "i2s-controller", 0);
  83
  84                 if (i2s_node) {
  85                         dai->cpus->dai_name = NULL;
  86                         dai->cpus->of_node = i2s_node;
  87                         dai->platforms->name = NULL;
  88                         dai->platforms->of_node = i2s_node;
  89                 }
  90
  91                 digital_gain_0db_limit = !of_property_read_bool(
  92                         pdev->dev.of_node, "allo,24db_digital_gain");
  93         }
  94
  95         ret = devm_snd_soc_register_card(&pdev->dev, &snd_allo_piano_dac);
  96         if (ret && ret != -EPROBE_DEFER)
  97                 dev_err(&pdev->dev,
  98                         "snd_soc_register_card() failed: %d\n", ret);
  99
 100         return ret;
 101 }
 102
 103 static const struct of_device_id snd_allo_piano_dac_of_match[] = {
 104         { .compatible = "allo,piano-dac", },
 105         { /* sentinel */ },
 106 };
 107 MODULE_DEVICE_TABLE(of, snd_allo_piano_dac_of_match);
 108
 109 static struct platform_driver snd_allo_piano_dac_driver = {
 110         .driver = {
 111                 .name   = "snd-allo-piano-dac",
 112                 .owner  = THIS_MODULE,
 113                 .of_match_table = snd_allo_piano_dac_of_match,
 114         },
 115         .probe          = snd_allo_piano_dac_probe,
 116 };
 117
 118 module_platform_driver(snd_allo_piano_dac_driver);
 119
 120 MODULE_AUTHOR("Baswaraj K <jaikumar@cem-solutions.net>");
 121 MODULE_DESCRIPTION("ALSA ASoC Machine Driver for Allo Piano DAC");
 122 MODULE_LICENSE("GPL v2");