linux/sound/soc/samsung/smdk_spdif.c
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   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 */
  24static 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);
  66out3:
  67        clk_put(sclk_audio0);
  68out2:
  69        clk_put(mout_epll);
  70out1:
  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 */
  80static 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
 106static 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
 147static struct snd_soc_ops smdk_spdif_ops = {
 148        .hw_params = smdk_hw_params,
 149};
 150
 151static struct snd_soc_dai_link smdk_dai = {
 152        .name = "S/PDIF",
 153        .stream_name = "S/PDIF PCM Playback",
 154        .platform_name = "samsung-audio",
 155        .cpu_dai_name = "samsung-spdif",
 156        .codec_dai_name = "dit-hifi",
 157        .codec_name = "spdif-dit",
 158        .ops = &smdk_spdif_ops,
 159};
 160
 161static struct snd_soc_card smdk = {
 162        .name = "SMDK-S/PDIF",
 163        .dai_link = &smdk_dai,
 164        .num_links = 1,
 165};
 166
 167static struct platform_device *smdk_snd_spdif_dit_device;
 168static struct platform_device *smdk_snd_spdif_device;
 169
 170static int __init smdk_init(void)
 171{
 172        int ret;
 173
 174        smdk_snd_spdif_dit_device = platform_device_alloc("spdif-dit", -1);
 175        if (!smdk_snd_spdif_dit_device)
 176                return -ENOMEM;
 177
 178        ret = platform_device_add(smdk_snd_spdif_dit_device);
 179        if (ret)
 180                goto err1;
 181
 182        smdk_snd_spdif_device = platform_device_alloc("soc-audio", -1);
 183        if (!smdk_snd_spdif_device) {
 184                ret = -ENOMEM;
 185                goto err2;
 186        }
 187
 188        platform_set_drvdata(smdk_snd_spdif_device, &smdk);
 189
 190        ret = platform_device_add(smdk_snd_spdif_device);
 191        if (ret)
 192                goto err3;
 193
 194        /* Set audio clock hierarchy manually */
 195        ret = set_audio_clock_heirachy(smdk_snd_spdif_device);
 196        if (ret)
 197                goto err4;
 198
 199        return 0;
 200err4:
 201        platform_device_del(smdk_snd_spdif_device);
 202err3:
 203        platform_device_put(smdk_snd_spdif_device);
 204err2:
 205        platform_device_del(smdk_snd_spdif_dit_device);
 206err1:
 207        platform_device_put(smdk_snd_spdif_dit_device);
 208        return ret;
 209}
 210
 211static void __exit smdk_exit(void)
 212{
 213        platform_device_unregister(smdk_snd_spdif_device);
 214        platform_device_unregister(smdk_snd_spdif_dit_device);
 215}
 216
 217module_init(smdk_init);
 218module_exit(smdk_exit);
 219
 220MODULE_AUTHOR("Seungwhan Youn, <sw.youn@samsung.com>");
 221MODULE_DESCRIPTION("ALSA SoC SMDK+S/PDIF");
 222MODULE_LICENSE("GPL");
 223