1 // SPDX-License-Identifier: GPL-2.0+
2 //
3 // smdk_spdif.c - S/PDIF audio for SMDK
4 //
5 // Copyright (C) 2010 Samsung Electronics Co., Ltd.
6 
7 #include <linux/clk.h>
8 #include <linux/module.h>
9 
10 #include <sound/soc.h>
11 
12 #include "spdif.h"
13 
14 /* Audio clock settings are belonged to board specific part. Every
15  * board can set audio source clock setting which is matched with H/W
16  * like this function-'set_audio_clock_heirachy'.
17  */
set_audio_clock_heirachy(struct platform_device * pdev)18 static int set_audio_clock_heirachy(struct platform_device *pdev)
19 {
20 	struct clk *fout_epll, *mout_epll, *sclk_audio0, *sclk_spdif;
21 	int ret = 0;
22 
23 	fout_epll = clk_get(NULL, "fout_epll");
24 	if (IS_ERR(fout_epll)) {
25 		printk(KERN_WARNING "%s: Cannot find fout_epll.\n",
26 				__func__);
27 		return -EINVAL;
28 	}
29 
30 	mout_epll = clk_get(NULL, "mout_epll");
31 	if (IS_ERR(mout_epll)) {
32 		printk(KERN_WARNING "%s: Cannot find mout_epll.\n",
33 				__func__);
34 		ret = -EINVAL;
35 		goto out1;
36 	}
37 
38 	sclk_audio0 = clk_get(&pdev->dev, "sclk_audio");
39 	if (IS_ERR(sclk_audio0)) {
40 		printk(KERN_WARNING "%s: Cannot find sclk_audio.\n",
41 				__func__);
42 		ret = -EINVAL;
43 		goto out2;
44 	}
45 
46 	sclk_spdif = clk_get(NULL, "sclk_spdif");
47 	if (IS_ERR(sclk_spdif)) {
48 		printk(KERN_WARNING "%s: Cannot find sclk_spdif.\n",
49 				__func__);
50 		ret = -EINVAL;
51 		goto out3;
52 	}
53 
54 	/* Set audio clock hierarchy for S/PDIF */
55 	clk_set_parent(mout_epll, fout_epll);
56 	clk_set_parent(sclk_audio0, mout_epll);
57 	clk_set_parent(sclk_spdif, sclk_audio0);
58 
59 	clk_put(sclk_spdif);
60 out3:
61 	clk_put(sclk_audio0);
62 out2:
63 	clk_put(mout_epll);
64 out1:
65 	clk_put(fout_epll);
66 
67 	return ret;
68 }
69 
70 /* We should haved to set clock directly on this part because of clock
71  * scheme of Samsudng SoCs did not support to set rates from abstrct
72  * clock of it's hierarchy.
73  */
set_audio_clock_rate(unsigned long epll_rate,unsigned long audio_rate)74 static int set_audio_clock_rate(unsigned long epll_rate,
75 				unsigned long audio_rate)
76 {
77 	struct clk *fout_epll, *sclk_spdif;
78 
79 	fout_epll = clk_get(NULL, "fout_epll");
80 	if (IS_ERR(fout_epll)) {
81 		printk(KERN_ERR "%s: failed to get fout_epll\n", __func__);
82 		return -ENOENT;
83 	}
84 
85 	clk_set_rate(fout_epll, epll_rate);
86 	clk_put(fout_epll);
87 
88 	sclk_spdif = clk_get(NULL, "sclk_spdif");
89 	if (IS_ERR(sclk_spdif)) {
90 		printk(KERN_ERR "%s: failed to get sclk_spdif\n", __func__);
91 		return -ENOENT;
92 	}
93 
94 	clk_set_rate(sclk_spdif, audio_rate);
95 	clk_put(sclk_spdif);
96 
97 	return 0;
98 }
99 
smdk_hw_params(struct snd_pcm_substream * substream,struct snd_pcm_hw_params * params)100 static int smdk_hw_params(struct snd_pcm_substream *substream,
101 		struct snd_pcm_hw_params *params)
102 {
103 	struct snd_soc_pcm_runtime *rtd = asoc_substream_to_rtd(substream);
104 	struct snd_soc_dai *cpu_dai = asoc_rtd_to_cpu(rtd, 0);
105 	unsigned long pll_out, rclk_rate;
106 	int ret, ratio;
107 
108 	switch (params_rate(params)) {
109 	case 44100:
110 		pll_out = 45158400;
111 		break;
112 	case 32000:
113 	case 48000:
114 	case 96000:
115 		pll_out = 49152000;
116 		break;
117 	default:
118 		return -EINVAL;
119 	}
120 
121 	/* Setting ratio to 512fs helps to use S/PDIF with HDMI without
122 	 * modify S/PDIF ASoC machine driver.
123 	 */
124 	ratio = 512;
125 	rclk_rate = params_rate(params) * ratio;
126 
127 	/* Set audio source clock rates */
128 	ret = set_audio_clock_rate(pll_out, rclk_rate);
129 	if (ret < 0)
130 		return ret;
131 
132 	/* Set S/PDIF uses internal source clock */
133 	ret = snd_soc_dai_set_sysclk(cpu_dai, SND_SOC_SPDIF_INT_MCLK,
134 					rclk_rate, SND_SOC_CLOCK_IN);
135 	if (ret < 0)
136 		return ret;
137 
138 	return ret;
139 }
140 
141 static const struct snd_soc_ops smdk_spdif_ops = {
142 	.hw_params = smdk_hw_params,
143 };
144 
145 SND_SOC_DAILINK_DEFS(spdif,
146 	DAILINK_COMP_ARRAY(COMP_CPU("samsung-spdif")),
147 	DAILINK_COMP_ARRAY(COMP_CODEC("spdif-dit", "dit-hifi")),
148 	DAILINK_COMP_ARRAY(COMP_PLATFORM("samsung-spdif")));
149 
150 static struct snd_soc_dai_link smdk_dai = {
151 	.name = "S/PDIF",
152 	.stream_name = "S/PDIF PCM Playback",
153 	.ops = &smdk_spdif_ops,
154 	SND_SOC_DAILINK_REG(spdif),
155 };
156 
157 static struct snd_soc_card smdk = {
158 	.name = "SMDK-S/PDIF",
159 	.owner = THIS_MODULE,
160 	.dai_link = &smdk_dai,
161 	.num_links = 1,
162 };
163 
164 static struct platform_device *smdk_snd_spdif_dit_device;
165 static struct platform_device *smdk_snd_spdif_device;
166 
smdk_init(void)167 static int __init smdk_init(void)
168 {
169 	int ret;
170 
171 	smdk_snd_spdif_dit_device = platform_device_alloc("spdif-dit", -1);
172 	if (!smdk_snd_spdif_dit_device)
173 		return -ENOMEM;
174 
175 	ret = platform_device_add(smdk_snd_spdif_dit_device);
176 	if (ret)
177 		goto err1;
178 
179 	smdk_snd_spdif_device = platform_device_alloc("soc-audio", -1);
180 	if (!smdk_snd_spdif_device) {
181 		ret = -ENOMEM;
182 		goto err2;
183 	}
184 
185 	platform_set_drvdata(smdk_snd_spdif_device, &smdk);
186 
187 	ret = platform_device_add(smdk_snd_spdif_device);
188 	if (ret)
189 		goto err3;
190 
191 	/* Set audio clock hierarchy manually */
192 	ret = set_audio_clock_heirachy(smdk_snd_spdif_device);
193 	if (ret)
194 		goto err4;
195 
196 	return 0;
197 err4:
198 	platform_device_del(smdk_snd_spdif_device);
199 err3:
200 	platform_device_put(smdk_snd_spdif_device);
201 err2:
202 	platform_device_del(smdk_snd_spdif_dit_device);
203 err1:
204 	platform_device_put(smdk_snd_spdif_dit_device);
205 	return ret;
206 }
207 
smdk_exit(void)208 static void __exit smdk_exit(void)
209 {
210 	platform_device_unregister(smdk_snd_spdif_device);
211 	platform_device_unregister(smdk_snd_spdif_dit_device);
212 }
213 
214 module_init(smdk_init);
215 module_exit(smdk_exit);
216 
217 MODULE_AUTHOR("Seungwhan Youn, <sw.youn@samsung.com>");
218 MODULE_DESCRIPTION("ALSA SoC SMDK+S/PDIF");
219 MODULE_LICENSE("GPL");
220