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