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7#include <linux/init.h>
8#include <linux/kernel.h>
9#include <linux/module.h>
10#include <linux/platform_device.h>
11#include <linux/slab.h>
12#include <linux/of.h>
13#include <linux/clk.h>
14#include <linux/regmap.h>
15
16#include <sound/core.h>
17#include <sound/pcm.h>
18#include <sound/pcm_params.h>
19#include <sound/soc.h>
20#include <sound/initval.h>
21#include <sound/dmaengine_pcm.h>
22
23#define AXI_SPDIF_REG_CTRL 0x0
24#define AXI_SPDIF_REG_STAT 0x4
25#define AXI_SPDIF_REG_TX_FIFO 0xc
26
27#define AXI_SPDIF_CTRL_TXDATA BIT(1)
28#define AXI_SPDIF_CTRL_TXEN BIT(0)
29#define AXI_SPDIF_CTRL_CLKDIV_OFFSET 8
30#define AXI_SPDIF_CTRL_CLKDIV_MASK (0xff << 8)
31
32#define AXI_SPDIF_FREQ_44100 (0x0 << 6)
33#define AXI_SPDIF_FREQ_48000 (0x1 << 6)
34#define AXI_SPDIF_FREQ_32000 (0x2 << 6)
35#define AXI_SPDIF_FREQ_NA (0x3 << 6)
36
37struct axi_spdif {
38 struct regmap *regmap;
39 struct clk *clk;
40 struct clk *clk_ref;
41
42 struct snd_dmaengine_dai_dma_data dma_data;
43
44 struct snd_ratnum ratnum;
45 struct snd_pcm_hw_constraint_ratnums rate_constraints;
46};
47
48static int axi_spdif_trigger(struct snd_pcm_substream *substream, int cmd,
49 struct snd_soc_dai *dai)
50{
51 struct axi_spdif *spdif = snd_soc_dai_get_drvdata(dai);
52 unsigned int val;
53
54 switch (cmd) {
55 case SNDRV_PCM_TRIGGER_START:
56 case SNDRV_PCM_TRIGGER_RESUME:
57 case SNDRV_PCM_TRIGGER_PAUSE_RELEASE:
58 val = AXI_SPDIF_CTRL_TXDATA;
59 break;
60 case SNDRV_PCM_TRIGGER_STOP:
61 case SNDRV_PCM_TRIGGER_SUSPEND:
62 case SNDRV_PCM_TRIGGER_PAUSE_PUSH:
63 val = 0;
64 break;
65 default:
66 return -EINVAL;
67 }
68
69 regmap_update_bits(spdif->regmap, AXI_SPDIF_REG_CTRL,
70 AXI_SPDIF_CTRL_TXDATA, val);
71
72 return 0;
73}
74
75static int axi_spdif_hw_params(struct snd_pcm_substream *substream,
76 struct snd_pcm_hw_params *params, struct snd_soc_dai *dai)
77{
78 struct axi_spdif *spdif = snd_soc_dai_get_drvdata(dai);
79 unsigned int rate = params_rate(params);
80 unsigned int clkdiv, stat;
81
82 switch (params_rate(params)) {
83 case 32000:
84 stat = AXI_SPDIF_FREQ_32000;
85 break;
86 case 44100:
87 stat = AXI_SPDIF_FREQ_44100;
88 break;
89 case 48000:
90 stat = AXI_SPDIF_FREQ_48000;
91 break;
92 default:
93 stat = AXI_SPDIF_FREQ_NA;
94 break;
95 }
96
97 clkdiv = DIV_ROUND_CLOSEST(clk_get_rate(spdif->clk_ref),
98 rate * 64 * 2) - 1;
99 clkdiv <<= AXI_SPDIF_CTRL_CLKDIV_OFFSET;
100
101 regmap_write(spdif->regmap, AXI_SPDIF_REG_STAT, stat);
102 regmap_update_bits(spdif->regmap, AXI_SPDIF_REG_CTRL,
103 AXI_SPDIF_CTRL_CLKDIV_MASK, clkdiv);
104
105 return 0;
106}
107
108static int axi_spdif_dai_probe(struct snd_soc_dai *dai)
109{
110 struct axi_spdif *spdif = snd_soc_dai_get_drvdata(dai);
111
112 snd_soc_dai_init_dma_data(dai, &spdif->dma_data, NULL);
113
114 return 0;
115}
116
117static int axi_spdif_startup(struct snd_pcm_substream *substream,
118 struct snd_soc_dai *dai)
119{
120 struct axi_spdif *spdif = snd_soc_dai_get_drvdata(dai);
121 int ret;
122
123 ret = snd_pcm_hw_constraint_ratnums(substream->runtime, 0,
124 SNDRV_PCM_HW_PARAM_RATE,
125 &spdif->rate_constraints);
126 if (ret)
127 return ret;
128
129 ret = clk_prepare_enable(spdif->clk_ref);
130 if (ret)
131 return ret;
132
133 regmap_update_bits(spdif->regmap, AXI_SPDIF_REG_CTRL,
134 AXI_SPDIF_CTRL_TXEN, AXI_SPDIF_CTRL_TXEN);
135
136 return 0;
137}
138
139static void axi_spdif_shutdown(struct snd_pcm_substream *substream,
140 struct snd_soc_dai *dai)
141{
142 struct axi_spdif *spdif = snd_soc_dai_get_drvdata(dai);
143
144 regmap_update_bits(spdif->regmap, AXI_SPDIF_REG_CTRL,
145 AXI_SPDIF_CTRL_TXEN, 0);
146
147 clk_disable_unprepare(spdif->clk_ref);
148}
149
150static const struct snd_soc_dai_ops axi_spdif_dai_ops = {
151 .startup = axi_spdif_startup,
152 .shutdown = axi_spdif_shutdown,
153 .trigger = axi_spdif_trigger,
154 .hw_params = axi_spdif_hw_params,
155};
156
157static struct snd_soc_dai_driver axi_spdif_dai = {
158 .probe = axi_spdif_dai_probe,
159 .playback = {
160 .channels_min = 2,
161 .channels_max = 2,
162 .rates = SNDRV_PCM_RATE_KNOT,
163 .formats = SNDRV_PCM_FMTBIT_S16_LE,
164 },
165 .ops = &axi_spdif_dai_ops,
166};
167
168static const struct snd_soc_component_driver axi_spdif_component = {
169 .name = "axi-spdif",
170};
171
172static const struct regmap_config axi_spdif_regmap_config = {
173 .reg_bits = 32,
174 .reg_stride = 4,
175 .val_bits = 32,
176 .max_register = AXI_SPDIF_REG_STAT,
177};
178
179static int axi_spdif_probe(struct platform_device *pdev)
180{
181 struct axi_spdif *spdif;
182 struct resource *res;
183 void __iomem *base;
184 int ret;
185
186 spdif = devm_kzalloc(&pdev->dev, sizeof(*spdif), GFP_KERNEL);
187 if (!spdif)
188 return -ENOMEM;
189
190 platform_set_drvdata(pdev, spdif);
191
192 res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
193 base = devm_ioremap_resource(&pdev->dev, res);
194 if (IS_ERR(base))
195 return PTR_ERR(base);
196
197 spdif->regmap = devm_regmap_init_mmio(&pdev->dev, base,
198 &axi_spdif_regmap_config);
199 if (IS_ERR(spdif->regmap))
200 return PTR_ERR(spdif->regmap);
201
202 spdif->clk = devm_clk_get(&pdev->dev, "axi");
203 if (IS_ERR(spdif->clk))
204 return PTR_ERR(spdif->clk);
205
206 spdif->clk_ref = devm_clk_get(&pdev->dev, "ref");
207 if (IS_ERR(spdif->clk_ref))
208 return PTR_ERR(spdif->clk_ref);
209
210 ret = clk_prepare_enable(spdif->clk);
211 if (ret)
212 return ret;
213
214 spdif->dma_data.addr = res->start + AXI_SPDIF_REG_TX_FIFO;
215 spdif->dma_data.addr_width = 4;
216 spdif->dma_data.maxburst = 1;
217
218 spdif->ratnum.num = clk_get_rate(spdif->clk_ref) / 128;
219 spdif->ratnum.den_step = 1;
220 spdif->ratnum.den_min = 1;
221 spdif->ratnum.den_max = 64;
222
223 spdif->rate_constraints.rats = &spdif->ratnum;
224 spdif->rate_constraints.nrats = 1;
225
226 ret = devm_snd_soc_register_component(&pdev->dev, &axi_spdif_component,
227 &axi_spdif_dai, 1);
228 if (ret)
229 goto err_clk_disable;
230
231 ret = devm_snd_dmaengine_pcm_register(&pdev->dev, NULL, 0);
232 if (ret)
233 goto err_clk_disable;
234
235 return 0;
236
237err_clk_disable:
238 clk_disable_unprepare(spdif->clk);
239 return ret;
240}
241
242static int axi_spdif_dev_remove(struct platform_device *pdev)
243{
244 struct axi_spdif *spdif = platform_get_drvdata(pdev);
245
246 clk_disable_unprepare(spdif->clk);
247
248 return 0;
249}
250
251static const struct of_device_id axi_spdif_of_match[] = {
252 { .compatible = "adi,axi-spdif-tx-1.00.a", },
253 {},
254};
255MODULE_DEVICE_TABLE(of, axi_spdif_of_match);
256
257static struct platform_driver axi_spdif_driver = {
258 .driver = {
259 .name = "axi-spdif",
260 .of_match_table = axi_spdif_of_match,
261 },
262 .probe = axi_spdif_probe,
263 .remove = axi_spdif_dev_remove,
264};
265module_platform_driver(axi_spdif_driver);
266
267MODULE_AUTHOR("Lars-Peter Clausen <lars@metafoo.de>");
268MODULE_DESCRIPTION("AXI SPDIF driver");
269MODULE_LICENSE("GPL");
270
