Staging
v0.7.0
v0.7.0
https://github.com/torvalds/linux
Tip revision: a0d271cbfed1dd50278c6b06bead3d00ba0a88f9 authored by Linus Torvalds on 30 September 2012, 23:47:46 UTC
Linux 3.6
Linux 3.6
Tip revision: a0d271c
smdk_spdif.c
/*
* smdk_spdif.c -- S/PDIF audio for SMDK
*
* Copyright 2010 Samsung Electronics Co. Ltd.
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License as
* published by the Free Software Foundation; either version 2 of the
* License, or (at your option) any later version.
*
*/
#include <linux/clk.h>
#include <linux/module.h>
#include <sound/soc.h>
#include "spdif.h"
/* Audio clock settings are belonged to board specific part. Every
* board can set audio source clock setting which is matched with H/W
* like this function-'set_audio_clock_heirachy'.
*/
static int set_audio_clock_heirachy(struct platform_device *pdev)
{
struct clk *fout_epll, *mout_epll, *sclk_audio0, *sclk_spdif;
int ret = 0;
fout_epll = clk_get(NULL, "fout_epll");
if (IS_ERR(fout_epll)) {
printk(KERN_WARNING "%s: Cannot find fout_epll.\n",
__func__);
return -EINVAL;
}
mout_epll = clk_get(NULL, "mout_epll");
if (IS_ERR(mout_epll)) {
printk(KERN_WARNING "%s: Cannot find mout_epll.\n",
__func__);
ret = -EINVAL;
goto out1;
}
sclk_audio0 = clk_get(&pdev->dev, "sclk_audio");
if (IS_ERR(sclk_audio0)) {
printk(KERN_WARNING "%s: Cannot find sclk_audio.\n",
__func__);
ret = -EINVAL;
goto out2;
}
sclk_spdif = clk_get(NULL, "sclk_spdif");
if (IS_ERR(sclk_spdif)) {
printk(KERN_WARNING "%s: Cannot find sclk_spdif.\n",
__func__);
ret = -EINVAL;
goto out3;
}
/* Set audio clock hierarchy for S/PDIF */
clk_set_parent(mout_epll, fout_epll);
clk_set_parent(sclk_audio0, mout_epll);
clk_set_parent(sclk_spdif, sclk_audio0);
clk_put(sclk_spdif);
out3:
clk_put(sclk_audio0);
out2:
clk_put(mout_epll);
out1:
clk_put(fout_epll);
return ret;
}
/* We should haved to set clock directly on this part because of clock
* scheme of Samsudng SoCs did not support to set rates from abstrct
* clock of it's hierarchy.
*/
static int set_audio_clock_rate(unsigned long epll_rate,
unsigned long audio_rate)
{
struct clk *fout_epll, *sclk_spdif;
fout_epll = clk_get(NULL, "fout_epll");
if (IS_ERR(fout_epll)) {
printk(KERN_ERR "%s: failed to get fout_epll\n", __func__);
return -ENOENT;
}
clk_set_rate(fout_epll, epll_rate);
clk_put(fout_epll);
sclk_spdif = clk_get(NULL, "sclk_spdif");
if (IS_ERR(sclk_spdif)) {
printk(KERN_ERR "%s: failed to get sclk_spdif\n", __func__);
return -ENOENT;
}
clk_set_rate(sclk_spdif, audio_rate);
clk_put(sclk_spdif);
return 0;
}
static int smdk_hw_params(struct snd_pcm_substream *substream,
struct snd_pcm_hw_params *params)
{
struct snd_soc_pcm_runtime *rtd = substream->private_data;
struct snd_soc_dai *cpu_dai = rtd->cpu_dai;
unsigned long pll_out, rclk_rate;
int ret, ratio;
switch (params_rate(params)) {
case 44100:
pll_out = 45158400;
break;
case 32000:
case 48000:
case 96000:
pll_out = 49152000;
break;
default:
return -EINVAL;
}
/* Setting ratio to 512fs helps to use S/PDIF with HDMI without
* modify S/PDIF ASoC machine driver.
*/
ratio = 512;
rclk_rate = params_rate(params) * ratio;
/* Set audio source clock rates */
ret = set_audio_clock_rate(pll_out, rclk_rate);
if (ret < 0)
return ret;
/* Set S/PDIF uses internal source clock */
ret = snd_soc_dai_set_sysclk(cpu_dai, SND_SOC_SPDIF_INT_MCLK,
rclk_rate, SND_SOC_CLOCK_IN);
if (ret < 0)
return ret;
return ret;
}
static struct snd_soc_ops smdk_spdif_ops = {
.hw_params = smdk_hw_params,
};
static struct snd_soc_dai_link smdk_dai = {
.name = "S/PDIF",
.stream_name = "S/PDIF PCM Playback",
.platform_name = "samsung-audio",
.cpu_dai_name = "samsung-spdif",
.codec_dai_name = "dit-hifi",
.codec_name = "spdif-dit",
.ops = &smdk_spdif_ops,
};
static struct snd_soc_card smdk = {
.name = "SMDK-S/PDIF",
.owner = THIS_MODULE,
.dai_link = &smdk_dai,
.num_links = 1,
};
static struct platform_device *smdk_snd_spdif_dit_device;
static struct platform_device *smdk_snd_spdif_device;
static int __init smdk_init(void)
{
int ret;
smdk_snd_spdif_dit_device = platform_device_alloc("spdif-dit", -1);
if (!smdk_snd_spdif_dit_device)
return -ENOMEM;
ret = platform_device_add(smdk_snd_spdif_dit_device);
if (ret)
goto err1;
smdk_snd_spdif_device = platform_device_alloc("soc-audio", -1);
if (!smdk_snd_spdif_device) {
ret = -ENOMEM;
goto err2;
}
platform_set_drvdata(smdk_snd_spdif_device, &smdk);
ret = platform_device_add(smdk_snd_spdif_device);
if (ret)
goto err3;
/* Set audio clock hierarchy manually */
ret = set_audio_clock_heirachy(smdk_snd_spdif_device);
if (ret)
goto err4;
return 0;
err4:
platform_device_del(smdk_snd_spdif_device);
err3:
platform_device_put(smdk_snd_spdif_device);
err2:
platform_device_del(smdk_snd_spdif_dit_device);
err1:
platform_device_put(smdk_snd_spdif_dit_device);
return ret;
}
static void __exit smdk_exit(void)
{
platform_device_unregister(smdk_snd_spdif_device);
platform_device_unregister(smdk_snd_spdif_dit_device);
}
module_init(smdk_init);
module_exit(smdk_exit);
MODULE_AUTHOR("Seungwhan Youn, <sw.youn@samsung.com>");
MODULE_DESCRIPTION("ALSA SoC SMDK+S/PDIF");
MODULE_LICENSE("GPL");