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-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
161static 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
168static struct platform_device *smdk_snd_spdif_dit_device;
169static struct platform_device *smdk_snd_spdif_device;
170
171static 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;
201err4:
202	platform_device_del(smdk_snd_spdif_device);
203err3:
204	platform_device_put(smdk_snd_spdif_device);
205err2:
206	platform_device_del(smdk_snd_spdif_dit_device);
207err1:
208	platform_device_put(smdk_snd_spdif_dit_device);
209	return ret;
210}
211
212static 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
218module_init(smdk_init);
219module_exit(smdk_exit);
220
221MODULE_AUTHOR("Seungwhan Youn, <sw.youn@samsung.com>");
222MODULE_DESCRIPTION("ALSA SoC SMDK+S/PDIF");
223MODULE_LICENSE("GPL");
224