1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3 * Copyright (C) 2012-2013, Analog Devices Inc.
4 * Author: Lars-Peter Clausen <lars@metafoo.de>
5 */
6
7 #include <linux/clk.h>
8 #include <linux/init.h>
9 #include <linux/kernel.h>
10 #include <linux/module.h>
11 #include <linux/of.h>
12 #include <linux/platform_device.h>
13 #include <linux/regmap.h>
14 #include <linux/slab.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/dmaengine_pcm.h>
21
22 #define AXI_I2S_REG_RESET 0x00
23 #define AXI_I2S_REG_CTRL 0x04
24 #define AXI_I2S_REG_CLK_CTRL 0x08
25 #define AXI_I2S_REG_STATUS 0x10
26
27 #define AXI_I2S_REG_RX_FIFO 0x28
28 #define AXI_I2S_REG_TX_FIFO 0x2C
29
30 #define AXI_I2S_RESET_GLOBAL BIT(0)
31 #define AXI_I2S_RESET_TX_FIFO BIT(1)
32 #define AXI_I2S_RESET_RX_FIFO BIT(2)
33
34 #define AXI_I2S_CTRL_TX_EN BIT(0)
35 #define AXI_I2S_CTRL_RX_EN BIT(1)
36
37 /* The frame size is configurable, but for now we always set it 64 bit */
38 #define AXI_I2S_BITS_PER_FRAME 64
39
40 struct axi_i2s {
41 struct regmap *regmap;
42 struct clk *clk;
43 struct clk *clk_ref;
44
45 bool has_capture;
46 bool has_playback;
47
48 struct snd_soc_dai_driver dai_driver;
49
50 struct snd_dmaengine_dai_dma_data capture_dma_data;
51 struct snd_dmaengine_dai_dma_data playback_dma_data;
52
53 struct snd_ratnum ratnum;
54 struct snd_pcm_hw_constraint_ratnums rate_constraints;
55 };
56
axi_i2s_trigger(struct snd_pcm_substream * substream,int cmd,struct snd_soc_dai * dai)57 static int axi_i2s_trigger(struct snd_pcm_substream *substream, int cmd,
58 struct snd_soc_dai *dai)
59 {
60 struct axi_i2s *i2s = snd_soc_dai_get_drvdata(dai);
61 unsigned int mask, val;
62
63 if (substream->stream == SNDRV_PCM_STREAM_CAPTURE)
64 mask = AXI_I2S_CTRL_RX_EN;
65 else
66 mask = AXI_I2S_CTRL_TX_EN;
67
68 switch (cmd) {
69 case SNDRV_PCM_TRIGGER_START:
70 case SNDRV_PCM_TRIGGER_RESUME:
71 case SNDRV_PCM_TRIGGER_PAUSE_RELEASE:
72 val = mask;
73 break;
74 case SNDRV_PCM_TRIGGER_STOP:
75 case SNDRV_PCM_TRIGGER_SUSPEND:
76 case SNDRV_PCM_TRIGGER_PAUSE_PUSH:
77 val = 0;
78 break;
79 default:
80 return -EINVAL;
81 }
82
83 regmap_update_bits(i2s->regmap, AXI_I2S_REG_CTRL, mask, val);
84
85 return 0;
86 }
87
axi_i2s_hw_params(struct snd_pcm_substream * substream,struct snd_pcm_hw_params * params,struct snd_soc_dai * dai)88 static int axi_i2s_hw_params(struct snd_pcm_substream *substream,
89 struct snd_pcm_hw_params *params, struct snd_soc_dai *dai)
90 {
91 struct axi_i2s *i2s = snd_soc_dai_get_drvdata(dai);
92 unsigned int bclk_div, word_size;
93 unsigned int bclk_rate;
94
95 bclk_rate = params_rate(params) * AXI_I2S_BITS_PER_FRAME;
96
97 word_size = AXI_I2S_BITS_PER_FRAME / 2 - 1;
98 bclk_div = DIV_ROUND_UP(clk_get_rate(i2s->clk_ref), bclk_rate) / 2 - 1;
99
100 regmap_write(i2s->regmap, AXI_I2S_REG_CLK_CTRL, (word_size << 16) |
101 bclk_div);
102
103 return 0;
104 }
105
axi_i2s_startup(struct snd_pcm_substream * substream,struct snd_soc_dai * dai)106 static int axi_i2s_startup(struct snd_pcm_substream *substream,
107 struct snd_soc_dai *dai)
108 {
109 struct axi_i2s *i2s = snd_soc_dai_get_drvdata(dai);
110 uint32_t mask;
111 int ret;
112
113 if (substream->stream == SNDRV_PCM_STREAM_CAPTURE)
114 mask = AXI_I2S_RESET_RX_FIFO;
115 else
116 mask = AXI_I2S_RESET_TX_FIFO;
117
118 regmap_write(i2s->regmap, AXI_I2S_REG_RESET, mask);
119
120 ret = snd_pcm_hw_constraint_ratnums(substream->runtime, 0,
121 SNDRV_PCM_HW_PARAM_RATE,
122 &i2s->rate_constraints);
123 if (ret)
124 return ret;
125
126 return clk_prepare_enable(i2s->clk_ref);
127 }
128
axi_i2s_shutdown(struct snd_pcm_substream * substream,struct snd_soc_dai * dai)129 static void axi_i2s_shutdown(struct snd_pcm_substream *substream,
130 struct snd_soc_dai *dai)
131 {
132 struct axi_i2s *i2s = snd_soc_dai_get_drvdata(dai);
133
134 clk_disable_unprepare(i2s->clk_ref);
135 }
136
axi_i2s_dai_probe(struct snd_soc_dai * dai)137 static int axi_i2s_dai_probe(struct snd_soc_dai *dai)
138 {
139 struct axi_i2s *i2s = snd_soc_dai_get_drvdata(dai);
140
141 snd_soc_dai_init_dma_data(
142 dai,
143 i2s->has_playback ? &i2s->playback_dma_data : NULL,
144 i2s->has_capture ? &i2s->capture_dma_data : NULL);
145
146 return 0;
147 }
148
149 static const struct snd_soc_dai_ops axi_i2s_dai_ops = {
150 .probe = axi_i2s_dai_probe,
151 .startup = axi_i2s_startup,
152 .shutdown = axi_i2s_shutdown,
153 .trigger = axi_i2s_trigger,
154 .hw_params = axi_i2s_hw_params,
155 };
156
157 static struct snd_soc_dai_driver axi_i2s_dai = {
158 .ops = &axi_i2s_dai_ops,
159 .symmetric_rate = 1,
160 };
161
162 static const struct snd_soc_component_driver axi_i2s_component = {
163 .name = "axi-i2s",
164 .legacy_dai_naming = 1,
165 };
166
167 static const struct regmap_config axi_i2s_regmap_config = {
168 .reg_bits = 32,
169 .reg_stride = 4,
170 .val_bits = 32,
171 .max_register = AXI_I2S_REG_STATUS,
172 };
173
axi_i2s_parse_of(struct axi_i2s * i2s,const struct device_node * np)174 static void axi_i2s_parse_of(struct axi_i2s *i2s, const struct device_node *np)
175 {
176 struct property *dma_names;
177 const char *dma_name;
178
179 of_property_for_each_string(np, "dma-names", dma_names, dma_name) {
180 if (strcmp(dma_name, "rx") == 0)
181 i2s->has_capture = true;
182 if (strcmp(dma_name, "tx") == 0)
183 i2s->has_playback = true;
184 }
185 }
186
axi_i2s_probe(struct platform_device * pdev)187 static int axi_i2s_probe(struct platform_device *pdev)
188 {
189 struct resource *res;
190 struct axi_i2s *i2s;
191 void __iomem *base;
192 int ret;
193
194 i2s = devm_kzalloc(&pdev->dev, sizeof(*i2s), GFP_KERNEL);
195 if (!i2s)
196 return -ENOMEM;
197
198 platform_set_drvdata(pdev, i2s);
199
200 axi_i2s_parse_of(i2s, pdev->dev.of_node);
201
202 base = devm_platform_get_and_ioremap_resource(pdev, 0, &res);
203 if (IS_ERR(base))
204 return PTR_ERR(base);
205
206 i2s->regmap = devm_regmap_init_mmio(&pdev->dev, base,
207 &axi_i2s_regmap_config);
208 if (IS_ERR(i2s->regmap))
209 return PTR_ERR(i2s->regmap);
210
211 i2s->clk = devm_clk_get(&pdev->dev, "axi");
212 if (IS_ERR(i2s->clk))
213 return PTR_ERR(i2s->clk);
214
215 i2s->clk_ref = devm_clk_get(&pdev->dev, "ref");
216 if (IS_ERR(i2s->clk_ref))
217 return PTR_ERR(i2s->clk_ref);
218
219 ret = clk_prepare_enable(i2s->clk);
220 if (ret)
221 return ret;
222
223 if (i2s->has_playback) {
224 axi_i2s_dai.playback.channels_min = 2;
225 axi_i2s_dai.playback.channels_max = 2;
226 axi_i2s_dai.playback.rates = SNDRV_PCM_RATE_KNOT;
227 axi_i2s_dai.playback.formats =
228 SNDRV_PCM_FMTBIT_S32_LE | SNDRV_PCM_FMTBIT_U32_LE;
229
230 i2s->playback_dma_data.addr = res->start + AXI_I2S_REG_TX_FIFO;
231 i2s->playback_dma_data.addr_width = 4;
232 i2s->playback_dma_data.maxburst = 1;
233 }
234
235 if (i2s->has_capture) {
236 axi_i2s_dai.capture.channels_min = 2;
237 axi_i2s_dai.capture.channels_max = 2;
238 axi_i2s_dai.capture.rates = SNDRV_PCM_RATE_KNOT;
239 axi_i2s_dai.capture.formats =
240 SNDRV_PCM_FMTBIT_S32_LE | SNDRV_PCM_FMTBIT_U32_LE;
241
242 i2s->capture_dma_data.addr = res->start + AXI_I2S_REG_RX_FIFO;
243 i2s->capture_dma_data.addr_width = 4;
244 i2s->capture_dma_data.maxburst = 1;
245 }
246
247 i2s->ratnum.num = clk_get_rate(i2s->clk_ref) / 2 / AXI_I2S_BITS_PER_FRAME;
248 i2s->ratnum.den_step = 1;
249 i2s->ratnum.den_min = 1;
250 i2s->ratnum.den_max = 64;
251
252 i2s->rate_constraints.rats = &i2s->ratnum;
253 i2s->rate_constraints.nrats = 1;
254
255 regmap_write(i2s->regmap, AXI_I2S_REG_RESET, AXI_I2S_RESET_GLOBAL);
256
257 ret = devm_snd_soc_register_component(&pdev->dev, &axi_i2s_component,
258 &axi_i2s_dai, 1);
259 if (ret)
260 goto err_clk_disable;
261
262 ret = devm_snd_dmaengine_pcm_register(&pdev->dev, NULL, 0);
263 if (ret)
264 goto err_clk_disable;
265
266 dev_info(&pdev->dev, "probed, capture %s, playback %s\n",
267 str_enabled_disabled(i2s->has_capture),
268 str_enabled_disabled(i2s->has_playback));
269
270 return 0;
271
272 err_clk_disable:
273 clk_disable_unprepare(i2s->clk);
274 return ret;
275 }
276
axi_i2s_dev_remove(struct platform_device * pdev)277 static void axi_i2s_dev_remove(struct platform_device *pdev)
278 {
279 struct axi_i2s *i2s = platform_get_drvdata(pdev);
280
281 clk_disable_unprepare(i2s->clk);
282 }
283
284 static const struct of_device_id axi_i2s_of_match[] = {
285 { .compatible = "adi,axi-i2s-1.00.a", },
286 {},
287 };
288 MODULE_DEVICE_TABLE(of, axi_i2s_of_match);
289
290 static struct platform_driver axi_i2s_driver = {
291 .driver = {
292 .name = "axi-i2s",
293 .of_match_table = axi_i2s_of_match,
294 },
295 .probe = axi_i2s_probe,
296 .remove = axi_i2s_dev_remove,
297 };
298 module_platform_driver(axi_i2s_driver);
299
300 MODULE_AUTHOR("Lars-Peter Clausen <lars@metafoo.de>");
301 MODULE_DESCRIPTION("AXI I2S driver");
302 MODULE_LICENSE("GPL");
303