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8#include <linux/init.h>
9#include <linux/kernel.h>
10#include <linux/module.h>
11#include <linux/platform_device.h>
12#include <linux/slab.h>
13#include <linux/of.h>
14#include <linux/clk.h>
15#include <linux/regmap.h>
16
17#include <sound/core.h>
18#include <sound/pcm.h>
19#include <sound/pcm_params.h>
20#include <sound/soc.h>
21#include <sound/initval.h>
22#include <sound/dmaengine_pcm.h>
23
24#define AXI_SPDIF_REG_CTRL 0x0
25#define AXI_SPDIF_REG_STAT 0x4
26#define AXI_SPDIF_REG_TX_FIFO 0xc
27
28#define AXI_SPDIF_CTRL_TXDATA BIT(1)
29#define AXI_SPDIF_CTRL_TXEN BIT(0)
30#define AXI_SPDIF_CTRL_CLKDIV_OFFSET 8
31#define AXI_SPDIF_CTRL_CLKDIV_MASK (0xff << 8)
32
33#define AXI_SPDIF_FREQ_44100 (0x0 << 6)
34#define AXI_SPDIF_FREQ_48000 (0x1 << 6)
35#define AXI_SPDIF_FREQ_32000 (0x2 << 6)
36#define AXI_SPDIF_FREQ_NA (0x3 << 6)
37
38struct axi_spdif {
39 struct regmap *regmap;
40 struct clk *clk;
41 struct clk *clk_ref;
42
43 struct snd_dmaengine_dai_dma_data dma_data;
44
45 struct snd_ratnum ratnum;
46 struct snd_pcm_hw_constraint_ratnums rate_constraints;
47};
48
49static int axi_spdif_trigger(struct snd_pcm_substream *substream, int cmd,
50 struct snd_soc_dai *dai)
51{
52 struct axi_spdif *spdif = snd_soc_dai_get_drvdata(dai);
53 unsigned int val;
54
55 switch (cmd) {
56 case SNDRV_PCM_TRIGGER_START:
57 case SNDRV_PCM_TRIGGER_RESUME:
58 case SNDRV_PCM_TRIGGER_PAUSE_RELEASE:
59 val = AXI_SPDIF_CTRL_TXDATA;
60 break;
61 case SNDRV_PCM_TRIGGER_STOP:
62 case SNDRV_PCM_TRIGGER_SUSPEND:
63 case SNDRV_PCM_TRIGGER_PAUSE_PUSH:
64 val = 0;
65 break;
66 default:
67 return -EINVAL;
68 }
69
70 regmap_update_bits(spdif->regmap, AXI_SPDIF_REG_CTRL,
71 AXI_SPDIF_CTRL_TXDATA, val);
72
73 return 0;
74}
75
76static int axi_spdif_hw_params(struct snd_pcm_substream *substream,
77 struct snd_pcm_hw_params *params, struct snd_soc_dai *dai)
78{
79 struct axi_spdif *spdif = snd_soc_dai_get_drvdata(dai);
80 unsigned int rate = params_rate(params);
81 unsigned int clkdiv, stat;
82
83 switch (params_rate(params)) {
84 case 32000:
85 stat = AXI_SPDIF_FREQ_32000;
86 break;
87 case 44100:
88 stat = AXI_SPDIF_FREQ_44100;
89 break;
90 case 48000:
91 stat = AXI_SPDIF_FREQ_48000;
92 break;
93 default:
94 stat = AXI_SPDIF_FREQ_NA;
95 break;
96 }
97
98 clkdiv = DIV_ROUND_CLOSEST(clk_get_rate(spdif->clk_ref),
99 rate * 64 * 2) - 1;
100 clkdiv <<= AXI_SPDIF_CTRL_CLKDIV_OFFSET;
101
102 regmap_write(spdif->regmap, AXI_SPDIF_REG_STAT, stat);
103 regmap_update_bits(spdif->regmap, AXI_SPDIF_REG_CTRL,
104 AXI_SPDIF_CTRL_CLKDIV_MASK, clkdiv);
105
106 return 0;
107}
108
109static int axi_spdif_dai_probe(struct snd_soc_dai *dai)
110{
111 struct axi_spdif *spdif = snd_soc_dai_get_drvdata(dai);
112
113 snd_soc_dai_init_dma_data(dai, &spdif->dma_data, NULL);
114
115 return 0;
116}
117
118static int axi_spdif_startup(struct snd_pcm_substream *substream,
119 struct snd_soc_dai *dai)
120{
121 struct axi_spdif *spdif = snd_soc_dai_get_drvdata(dai);
122 int ret;
123
124 ret = snd_pcm_hw_constraint_ratnums(substream->runtime, 0,
125 SNDRV_PCM_HW_PARAM_RATE,
126 &spdif->rate_constraints);
127 if (ret)
128 return ret;
129
130 ret = clk_prepare_enable(spdif->clk_ref);
131 if (ret)
132 return ret;
133
134 regmap_update_bits(spdif->regmap, AXI_SPDIF_REG_CTRL,
135 AXI_SPDIF_CTRL_TXEN, AXI_SPDIF_CTRL_TXEN);
136
137 return 0;
138}
139
140static void axi_spdif_shutdown(struct snd_pcm_substream *substream,
141 struct snd_soc_dai *dai)
142{
143 struct axi_spdif *spdif = snd_soc_dai_get_drvdata(dai);
144
145 regmap_update_bits(spdif->regmap, AXI_SPDIF_REG_CTRL,
146 AXI_SPDIF_CTRL_TXEN, 0);
147
148 clk_disable_unprepare(spdif->clk_ref);
149}
150
151static const struct snd_soc_dai_ops axi_spdif_dai_ops = {
152 .startup = axi_spdif_startup,
153 .shutdown = axi_spdif_shutdown,
154 .trigger = axi_spdif_trigger,
155 .hw_params = axi_spdif_hw_params,
156};
157
158static struct snd_soc_dai_driver axi_spdif_dai = {
159 .probe = axi_spdif_dai_probe,
160 .playback = {
161 .channels_min = 2,
162 .channels_max = 2,
163 .rates = SNDRV_PCM_RATE_KNOT,
164 .formats = SNDRV_PCM_FMTBIT_S16_LE,
165 },
166 .ops = &axi_spdif_dai_ops,
167};
168
169static const struct snd_soc_component_driver axi_spdif_component = {
170 .name = "axi-spdif",
171};
172
173static const struct regmap_config axi_spdif_regmap_config = {
174 .reg_bits = 32,
175 .reg_stride = 4,
176 .val_bits = 32,
177 .max_register = AXI_SPDIF_REG_STAT,
178};
179
180static int axi_spdif_probe(struct platform_device *pdev)
181{
182 struct axi_spdif *spdif;
183 struct resource *res;
184 void __iomem *base;
185 int ret;
186
187 spdif = devm_kzalloc(&pdev->dev, sizeof(*spdif), GFP_KERNEL);
188 if (!spdif)
189 return -ENOMEM;
190
191 platform_set_drvdata(pdev, spdif);
192
193 res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
194 base = devm_ioremap_resource(&pdev->dev, res);
195 if (IS_ERR(base))
196 return PTR_ERR(base);
197
198 spdif->regmap = devm_regmap_init_mmio(&pdev->dev, base,
199 &axi_spdif_regmap_config);
200 if (IS_ERR(spdif->regmap))
201 return PTR_ERR(spdif->regmap);
202
203 spdif->clk = devm_clk_get(&pdev->dev, "axi");
204 if (IS_ERR(spdif->clk))
205 return PTR_ERR(spdif->clk);
206
207 spdif->clk_ref = devm_clk_get(&pdev->dev, "ref");
208 if (IS_ERR(spdif->clk_ref))
209 return PTR_ERR(spdif->clk_ref);
210
211 ret = clk_prepare_enable(spdif->clk);
212 if (ret)
213 return ret;
214
215 spdif->dma_data.addr = res->start + AXI_SPDIF_REG_TX_FIFO;
216 spdif->dma_data.addr_width = 4;
217 spdif->dma_data.maxburst = 1;
218
219 spdif->ratnum.num = clk_get_rate(spdif->clk_ref) / 128;
220 spdif->ratnum.den_step = 1;
221 spdif->ratnum.den_min = 1;
222 spdif->ratnum.den_max = 64;
223
224 spdif->rate_constraints.rats = &spdif->ratnum;
225 spdif->rate_constraints.nrats = 1;
226
227 ret = devm_snd_soc_register_component(&pdev->dev, &axi_spdif_component,
228 &axi_spdif_dai, 1);
229 if (ret)
230 goto err_clk_disable;
231
232 ret = devm_snd_dmaengine_pcm_register(&pdev->dev, NULL, 0);
233 if (ret)
234 goto err_clk_disable;
235
236 return 0;
237
238err_clk_disable:
239 clk_disable_unprepare(spdif->clk);
240 return ret;
241}
242
243static int axi_spdif_dev_remove(struct platform_device *pdev)
244{
245 struct axi_spdif *spdif = platform_get_drvdata(pdev);
246
247 clk_disable_unprepare(spdif->clk);
248
249 return 0;
250}
251
252static const struct of_device_id axi_spdif_of_match[] = {
253 { .compatible = "adi,axi-spdif-tx-1.00.a", },
254 {},
255};
256MODULE_DEVICE_TABLE(of, axi_spdif_of_match);
257
258static struct platform_driver axi_spdif_driver = {
259 .driver = {
260 .name = "axi-spdif",
261 .of_match_table = axi_spdif_of_match,
262 },
263 .probe = axi_spdif_probe,
264 .remove = axi_spdif_dev_remove,
265};
266module_platform_driver(axi_spdif_driver);
267
268MODULE_AUTHOR("Lars-Peter Clausen <lars@metafoo.de>");
269MODULE_DESCRIPTION("AXI SPDIF driver");
270MODULE_LICENSE("GPL");
271
