sound/soc/samsung/smdk_spdif.c

   1 /*
   2  * smdk_spdif.c  --  S/PDIF audio for SMDK
   3  *
   4  * Copyright 2010 Samsung Electronics Co. Ltd.
   5  *
   6  * This program is free software; you can redistribute it and/or
   7  * modify it under the terms of the GNU General Public License as
   8  * published by the Free Software Foundation; either version 2 of the
   9  * License, or (at your option) any later version.
  10  *
  11  */
  12
  13 #include <linux/clk.h>
  14 #include <linux/module.h>
  15
  16 #include <sound/soc.h>
  17
  18 #include "spdif.h"
  19
  20 /* Audio clock settings are belonged to board specific part. Every
  21  * board can set audio source clock setting which is matched with H/W
  22  * like this function-'set_audio_clock_heirachy'.
  23  */
  24 static int set_audio_clock_heirachy(struct platform_device *pdev)
  25 {
  26         struct clk *fout_epll, *mout_epll, *sclk_audio0, *sclk_spdif;
  27         int ret = 0;
  28
  29         fout_epll = clk_get(NULL, "fout_epll");
  30         if (IS_ERR(fout_epll)) {
  31                 printk(KERN_WARNING "%s: Cannot find fout_epll.\n",
  32                                 __func__);
  33                 return -EINVAL;
  34         }
  35
  36         mout_epll = clk_get(NULL, "mout_epll");
  37         if (IS_ERR(mout_epll)) {
  38                 printk(KERN_WARNING "%s: Cannot find mout_epll.\n",
  39                                 __func__);
  40                 ret = -EINVAL;
  41                 goto out1;
  42         }
  43
  44         sclk_audio0 = clk_get(&pdev->dev, "sclk_audio");
  45         if (IS_ERR(sclk_audio0)) {
  46                 printk(KERN_WARNING "%s: Cannot find sclk_audio.\n",
  47                                 __func__);
  48                 ret = -EINVAL;
  49                 goto out2;
  50         }
  51
  52         sclk_spdif = clk_get(NULL, "sclk_spdif");
  53         if (IS_ERR(sclk_spdif)) {
  54                 printk(KERN_WARNING "%s: Cannot find sclk_spdif.\n",
  55                                 __func__);
  56                 ret = -EINVAL;
  57                 goto out3;
  58         }
  59
  60         /* Set audio clock hierarchy for S/PDIF */
  61         clk_set_parent(mout_epll, fout_epll);
  62         clk_set_parent(sclk_audio0, mout_epll);
  63         clk_set_parent(sclk_spdif, sclk_audio0);
  64
  65         clk_put(sclk_spdif);
  66 out3:
  67         clk_put(sclk_audio0);
  68 out2:
  69         clk_put(mout_epll);
  70 out1:
  71         clk_put(fout_epll);
  72
  73         return ret;
  74 }
  75
  76 /* We should haved to set clock directly on this part because of clock
  77  * scheme of Samsudng SoCs did not support to set rates from abstrct
  78  * clock of it's hierarchy.
  79  */
  80 static int set_audio_clock_rate(unsigned long epll_rate,
  81                                 unsigned long audio_rate)
  82 {
  83         struct clk *fout_epll, *sclk_spdif;
  84
  85         fout_epll = clk_get(NULL, "fout_epll");
  86         if (IS_ERR(fout_epll)) {
  87                 printk(KERN_ERR "%s: failed to get fout_epll\n", __func__);
  88                 return -ENOENT;
  89         }
  90
  91         clk_set_rate(fout_epll, epll_rate);
  92         clk_put(fout_epll);
  93
  94         sclk_spdif = clk_get(NULL, "sclk_spdif");
  95         if (IS_ERR(sclk_spdif)) {
  96                 printk(KERN_ERR "%s: failed to get sclk_spdif\n", __func__);
  97                 return -ENOENT;
  98         }
  99
 100         clk_set_rate(sclk_spdif, audio_rate);
 101         clk_put(sclk_spdif);
 102
 103         return 0;
 104 }
 105
 106 static int smdk_hw_params(struct snd_pcm_substream *substream,
 107                 struct snd_pcm_hw_params *params)
 108 {
 109         struct snd_soc_pcm_runtime *rtd = substream->private_data;
 110         struct snd_soc_dai *cpu_dai = rtd->cpu_dai;
 111         unsigned long pll_out, rclk_rate;
 112         int ret, ratio;
 113
 114         switch (params_rate(params)) {
 115         case 44100:
 116                 pll_out = 45158400;
 117                 break;
 118         case 32000:
 119         case 48000:
 120         case 96000:
 121                 pll_out = 49152000;
 122                 break;
 123         default:
 124                 return -EINVAL;
 125         }
 126
 127         /* Setting ratio to 512fs helps to use S/PDIF with HDMI without
 128          * modify S/PDIF ASoC machine driver.
 129          */
 130         ratio = 512;
 131         rclk_rate = params_rate(params) * ratio;
 132
 133         /* Set audio source clock rates */
 134         ret = set_audio_clock_rate(pll_out, rclk_rate);
 135         if (ret < 0)
 136                 return ret;
 137
 138         /* Set S/PDIF uses internal source clock */
 139         ret = snd_soc_dai_set_sysclk(cpu_dai, SND_SOC_SPDIF_INT_MCLK,
 140                                         rclk_rate, SND_SOC_CLOCK_IN);
 141         if (ret < 0)
 142                 return ret;
 143
 144         return ret;
 145 }
 146
 147 static struct snd_soc_ops smdk_spdif_ops = {
 148         .hw_params = smdk_hw_params,
 149 };
 150
 151 static struct snd_soc_dai_link smdk_dai = {
 152         .name = "S/PDIF",
 153         .stream_name = "S/PDIF PCM Playback",
 154         .platform_name = "samsung-spdif",
 155         .cpu_dai_name = "samsung-spdif",
 156         .codec_dai_name = "dit-hifi",
 157         .codec_name = "spdif-dit",
 158         .ops = &smdk_spdif_ops,
 159 };
 160
 161 static struct snd_soc_card smdk = {
 162         .name = "SMDK-S/PDIF",
 163         .owner = THIS_MODULE,
 164         .dai_link = &smdk_dai,
 165         .num_links = 1,
 166 };
 167
 168 static struct platform_device *smdk_snd_spdif_dit_device;
 169 static struct platform_device *smdk_snd_spdif_device;
 170
 171 static int __init smdk_init(void)
 172 {
 173         int ret;
 174
 175         smdk_snd_spdif_dit_device = platform_device_alloc("spdif-dit", -1);
 176         if (!smdk_snd_spdif_dit_device)
 177                 return -ENOMEM;
 178
 179         ret = platform_device_add(smdk_snd_spdif_dit_device);
 180         if (ret)
 181                 goto err1;
 182
 183         smdk_snd_spdif_device = platform_device_alloc("soc-audio", -1);
 184         if (!smdk_snd_spdif_device) {
 185                 ret = -ENOMEM;
 186                 goto err2;
 187         }
 188
 189         platform_set_drvdata(smdk_snd_spdif_device, &smdk);
 190
 191         ret = platform_device_add(smdk_snd_spdif_device);
 192         if (ret)
 193                 goto err3;
 194
 195         /* Set audio clock hierarchy manually */
 196         ret = set_audio_clock_heirachy(smdk_snd_spdif_device);
 197         if (ret)
 198                 goto err4;
 199
 200         return 0;
 201 err4:
 202         platform_device_del(smdk_snd_spdif_device);
 203 err3:
 204         platform_device_put(smdk_snd_spdif_device);
 205 err2:
 206         platform_device_del(smdk_snd_spdif_dit_device);
 207 err1:
 208         platform_device_put(smdk_snd_spdif_dit_device);
 209         return ret;
 210 }
 211
 212 static void __exit smdk_exit(void)
 213 {
 214         platform_device_unregister(smdk_snd_spdif_device);
 215         platform_device_unregister(smdk_snd_spdif_dit_device);
 216 }
 217
 218 module_init(smdk_init);
 219 module_exit(smdk_exit);
 220
 221 MODULE_AUTHOR("Seungwhan Youn, <sw.youn@samsung.com>");
 222 MODULE_DESCRIPTION("ALSA SoC SMDK+S/PDIF");
 223 MODULE_LICENSE("GPL");