sound/soc/bcm/rpi-proto.c

   1 /*
   2  * ASoC driver for PROTO AudioCODEC (with a WM8731)
   3  * connected to a Raspberry Pi
   4  *
   5  * Author:      Florian Meier, <koalo@koalo.de>
   6  *            Copyright 2013
   7  *
   8  * This program is free software; you can redistribute it and/or modify
   9  * it under the terms of the GNU General Public License version 2 as
  10  * published by the Free Software Foundation.
  11  */
  12
  13 #include <linux/module.h>
  14 #include <linux/platform_device.h>
  15
  16 #include <sound/core.h>
  17 #include <sound/pcm.h>
  18 #include <sound/soc.h>
  19 #include <sound/jack.h>
  20
  21 #include "../codecs/wm8731.h"
  22
  23 static const unsigned int wm8731_rates_12288000[] = {
  24         8000, 32000, 48000, 96000,
  25 };
  26
  27 static struct snd_pcm_hw_constraint_list wm8731_constraints_12288000 = {
  28         .list = wm8731_rates_12288000,
  29         .count = ARRAY_SIZE(wm8731_rates_12288000),
  30 };
  31
  32 static int snd_rpi_proto_startup(struct snd_pcm_substream *substream)
  33 {
  34         /* Setup constraints, because there is a 12.288 MHz XTAL on the board */
  35         snd_pcm_hw_constraint_list(substream->runtime, 0,
  36                                 SNDRV_PCM_HW_PARAM_RATE,
  37                                 &wm8731_constraints_12288000);
  38         return 0;
  39 }
  40
  41 static int snd_rpi_proto_hw_params(struct snd_pcm_substream *substream,
  42                                        struct snd_pcm_hw_params *params)
  43 {
  44         struct snd_soc_pcm_runtime *rtd = substream->private_data;
  45         struct snd_soc_codec *codec = rtd->codec;
  46         struct snd_soc_dai *codec_dai = rtd->codec_dai;
  47         struct snd_soc_dai *cpu_dai = rtd->cpu_dai;
  48         int sysclk = 12288000; /* This is fixed on this board */
  49
  50         /* Set proto bclk */
  51         int ret = snd_soc_dai_set_bclk_ratio(cpu_dai,32*2);
  52         if (ret < 0){
  53                 dev_err(codec->dev,
  54                                 "Failed to set BCLK ratio %d\n", ret);
  55                 return ret;
  56         }
  57
  58         /* Set proto sysclk */
  59         ret = snd_soc_dai_set_sysclk(codec_dai, WM8731_SYSCLK_XTAL,
  60                         sysclk, SND_SOC_CLOCK_IN);
  61         if (ret < 0) {
  62                 dev_err(codec->dev,
  63                                 "Failed to set WM8731 SYSCLK: %d\n", ret);
  64                 return ret;
  65         }
  66
  67         return 0;
  68 }
  69
  70 /* machine stream operations */
  71 static struct snd_soc_ops snd_rpi_proto_ops = {
  72         .startup = snd_rpi_proto_startup,
  73         .hw_params = snd_rpi_proto_hw_params,
  74 };
  75
  76 static struct snd_soc_dai_link snd_rpi_proto_dai[] = {
  77 {
  78         .name           = "WM8731",
  79         .stream_name    = "WM8731 HiFi",
  80         .cpu_dai_name   = "bcm2708-i2s.0",
  81         .codec_dai_name = "wm8731-hifi",
  82         .platform_name  = "bcm2708-i2s.0",
  83         .codec_name     = "wm8731.1-001a",
  84         .dai_fmt        = SND_SOC_DAIFMT_I2S
  85                                 | SND_SOC_DAIFMT_NB_NF
  86                                 | SND_SOC_DAIFMT_CBM_CFM,
  87         .ops            = &snd_rpi_proto_ops,
  88 },
  89 };
  90
  91 /* audio machine driver */
  92 static struct snd_soc_card snd_rpi_proto = {
  93         .name           = "snd_rpi_proto",
  94         .owner          = THIS_MODULE,
  95         .dai_link       = snd_rpi_proto_dai,
  96         .num_links      = ARRAY_SIZE(snd_rpi_proto_dai),
  97 };
  98
  99 static int snd_rpi_proto_probe(struct platform_device *pdev)
 100 {
 101         int ret = 0;
 102
 103         snd_rpi_proto.dev = &pdev->dev;
 104
 105         if (pdev->dev.of_node) {
 106                 struct device_node *i2s_node;
 107                 struct snd_soc_dai_link *dai = &snd_rpi_proto_dai[0];
 108                 i2s_node = of_parse_phandle(pdev->dev.of_node,
 109                                             "i2s-controller", 0);
 110
 111                 if (i2s_node) {
 112                         dai->cpu_dai_name = NULL;
 113                         dai->cpu_of_node = i2s_node;
 114                         dai->platform_name = NULL;
 115                         dai->platform_of_node = i2s_node;
 116                 }
 117         }
 118
 119         ret = snd_soc_register_card(&snd_rpi_proto);
 120         if (ret) {
 121                 dev_err(&pdev->dev,
 122                                 "snd_soc_register_card() failed: %d\n", ret);
 123         }
 124
 125         return ret;
 126 }
 127
 128
 129 static int snd_rpi_proto_remove(struct platform_device *pdev)
 130 {
 131         return snd_soc_unregister_card(&snd_rpi_proto);
 132 }
 133
 134 static const struct of_device_id snd_rpi_proto_of_match[] = {
 135         { .compatible = "rpi,rpi-proto", },
 136         {},
 137 };
 138 MODULE_DEVICE_TABLE(of, snd_rpi_proto_of_match);
 139
 140 static struct platform_driver snd_rpi_proto_driver = {
 141         .driver = {
 142                 .name   = "snd-rpi-proto",
 143                 .owner  = THIS_MODULE,
 144                 .of_match_table = snd_rpi_proto_of_match,
 145         },
 146         .probe    = snd_rpi_proto_probe,
 147         .remove  = snd_rpi_proto_remove,
 148 };
 149
 150 module_platform_driver(snd_rpi_proto_driver);
 151
 152 MODULE_AUTHOR("Florian Meier");
 153 MODULE_DESCRIPTION("ASoC Driver for Raspberry Pi connected to PROTO board (WM8731)");
 154 MODULE_LICENSE("GPL");