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 */
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 */
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
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 = snd_soc_substream_to_rtd(substream);
104 struct snd_soc_dai *cpu_dai = snd_soc_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
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
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
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