1 // SPDX-License-Identifier: GPL-2.0
2 /*
3 * This file is part of STM32 DFSDM ASoC DAI driver
4 *
5 * Copyright (C) 2017, STMicroelectronics - All Rights Reserved
6 * Authors: Arnaud Pouliquen <arnaud.pouliquen@st.com>
7 * Olivier Moysan <olivier.moysan@st.com>
8 */
9
10 #include <linux/clk.h>
11 #include <linux/module.h>
12 #include <linux/mutex.h>
13 #include <linux/platform_device.h>
14 #include <linux/slab.h>
15 #include <linux/pm_runtime.h>
16 #include <linux/iio/iio.h>
17 #include <linux/iio/consumer.h>
18 #include <linux/iio/adc/stm32-dfsdm-adc.h>
19
20 #include <sound/pcm.h>
21 #include <sound/soc.h>
22
23 #define STM32_ADFSDM_DRV_NAME "stm32-adfsdm"
24
25 #define DFSDM_MAX_PERIOD_SIZE (PAGE_SIZE / 2)
26 #define DFSDM_MAX_PERIODS 6
27
28 struct stm32_adfsdm_priv {
29 struct snd_soc_dai_driver dai_drv;
30 struct snd_pcm_substream *substream;
31 struct device *dev;
32
33 /* IIO */
34 struct iio_channel *iio_ch;
35 struct iio_cb_buffer *iio_cb;
36 bool iio_active;
37
38 /* PCM buffer */
39 unsigned char *pcm_buff;
40 unsigned int pos;
41
42 struct mutex lock; /* protect against race condition on iio state */
43 };
44
45 static const struct snd_pcm_hardware stm32_adfsdm_pcm_hw = {
46 .info = SNDRV_PCM_INFO_INTERLEAVED | SNDRV_PCM_INFO_BLOCK_TRANSFER |
47 SNDRV_PCM_INFO_MMAP | SNDRV_PCM_INFO_PAUSE,
48 .formats = SNDRV_PCM_FMTBIT_S16_LE | SNDRV_PCM_FMTBIT_S32_LE,
49
50 .channels_min = 1,
51 .channels_max = 1,
52
53 .periods_min = 2,
54 .periods_max = DFSDM_MAX_PERIODS,
55
56 .period_bytes_max = DFSDM_MAX_PERIOD_SIZE,
57 .buffer_bytes_max = DFSDM_MAX_PERIODS * DFSDM_MAX_PERIOD_SIZE
58 };
59
60 static void stm32_adfsdm_shutdown(struct snd_pcm_substream *substream,
61 struct snd_soc_dai *dai)
62 {
63 struct stm32_adfsdm_priv *priv = snd_soc_dai_get_drvdata(dai);
64
65 mutex_lock(&priv->lock);
66 if (priv->iio_active) {
67 iio_channel_stop_all_cb(priv->iio_cb);
68 priv->iio_active = false;
69 }
70 mutex_unlock(&priv->lock);
71 }
72
73 static int stm32_adfsdm_dai_prepare(struct snd_pcm_substream *substream,
74 struct snd_soc_dai *dai)
75 {
76 struct stm32_adfsdm_priv *priv = snd_soc_dai_get_drvdata(dai);
77 int ret;
78
79 mutex_lock(&priv->lock);
80 if (priv->iio_active) {
81 iio_channel_stop_all_cb(priv->iio_cb);
82 priv->iio_active = false;
83 }
84
85 ret = iio_write_channel_attribute(priv->iio_ch,
86 substream->runtime->rate, 0,
87 IIO_CHAN_INFO_SAMP_FREQ);
88 if (ret < 0) {
89 dev_err(dai->dev, "%s: Failed to set %d sampling rate\n",
90 __func__, substream->runtime->rate);
91 goto out;
92 }
93
94 if (!priv->iio_active) {
95 ret = iio_channel_start_all_cb(priv->iio_cb);
96 if (!ret)
97 priv->iio_active = true;
98 else
99 dev_err(dai->dev, "%s: IIO channel start failed (%d)\n",
100 __func__, ret);
101 }
102
103 out:
104 mutex_unlock(&priv->lock);
105
106 return ret;
107 }
108
109 static int stm32_adfsdm_set_sysclk(struct snd_soc_dai *dai, int clk_id,
110 unsigned int freq, int dir)
111 {
112 struct stm32_adfsdm_priv *priv = snd_soc_dai_get_drvdata(dai);
113 ssize_t size;
114 char str_freq[10];
115
116 dev_dbg(dai->dev, "%s: Enter for freq %d\n", __func__, freq);
117
118 /* Set IIO frequency if CODEC is master as clock comes from SPI_IN */
119
120 snprintf(str_freq, sizeof(str_freq), "%u\n", freq);
121 size = iio_write_channel_ext_info(priv->iio_ch, "spi_clk_freq",
122 str_freq, sizeof(str_freq));
123 if (size != sizeof(str_freq)) {
124 dev_err(dai->dev, "%s: Failed to set SPI clock\n",
125 __func__);
126 return -EINVAL;
127 }
128 return 0;
129 }
130
131 static const struct snd_soc_dai_ops stm32_adfsdm_dai_ops = {
132 .shutdown = stm32_adfsdm_shutdown,
133 .prepare = stm32_adfsdm_dai_prepare,
134 .set_sysclk = stm32_adfsdm_set_sysclk,
135 };
136
137 static const struct snd_soc_dai_driver stm32_adfsdm_dai = {
138 .capture = {
139 .channels_min = 1,
140 .channels_max = 1,
141 .formats = SNDRV_PCM_FMTBIT_S16_LE |
142 SNDRV_PCM_FMTBIT_S32_LE,
143 .rates = SNDRV_PCM_RATE_CONTINUOUS,
144 .rate_min = 8000,
145 .rate_max = 48000,
146 },
147 .ops = &stm32_adfsdm_dai_ops,
148 };
149
150 static const struct snd_soc_component_driver stm32_adfsdm_dai_component = {
151 .name = "stm32_dfsdm_audio",
152 .legacy_dai_naming = 1,
153 };
154
155 static void stm32_memcpy_32to16(void *dest, const void *src, size_t n)
156 {
157 unsigned int i = 0;
158 u16 *d = (u16 *)dest, *s = (u16 *)src;
159
160 s++;
161 for (i = n >> 1; i > 0; i--) {
162 *d++ = *s++;
163 s++;
164 }
165 }
166
167 static int stm32_afsdm_pcm_cb(const void *data, size_t size, void *private)
168 {
169 struct stm32_adfsdm_priv *priv = private;
170 struct snd_soc_pcm_runtime *rtd = snd_soc_substream_to_rtd(priv->substream);
171 u8 *pcm_buff = priv->pcm_buff;
172 u8 *src_buff = (u8 *)data;
173 unsigned int old_pos = priv->pos;
174 size_t buff_size = snd_pcm_lib_buffer_bytes(priv->substream);
175 size_t period_size = snd_pcm_lib_period_bytes(priv->substream);
176 size_t cur_size, src_size = size;
177 snd_pcm_format_t format = priv->substream->runtime->format;
178
179 if (format == SNDRV_PCM_FORMAT_S16_LE)
180 src_size >>= 1;
181 cur_size = src_size;
182
183 dev_dbg(rtd->dev, "%s: buff_add :%pK, pos = %d, size = %zu\n",
184 __func__, &pcm_buff[priv->pos], priv->pos, src_size);
185
186 if ((priv->pos + src_size) > buff_size) {
187 if (format == SNDRV_PCM_FORMAT_S16_LE)
188 stm32_memcpy_32to16(&pcm_buff[priv->pos], src_buff,
189 buff_size - priv->pos);
190 else
191 memcpy(&pcm_buff[priv->pos], src_buff,
192 buff_size - priv->pos);
193 cur_size -= buff_size - priv->pos;
194 priv->pos = 0;
195 }
196
197 if (format == SNDRV_PCM_FORMAT_S16_LE)
198 stm32_memcpy_32to16(&pcm_buff[priv->pos],
199 &src_buff[src_size - cur_size], cur_size);
200 else
201 memcpy(&pcm_buff[priv->pos], &src_buff[src_size - cur_size],
202 cur_size);
203
204 priv->pos = (priv->pos + cur_size) % buff_size;
205
206 if (cur_size != src_size || (old_pos && (old_pos % period_size < size)))
207 snd_pcm_period_elapsed(priv->substream);
208
209 return 0;
210 }
211
212 static int stm32_adfsdm_trigger(struct snd_soc_component *component,
213 struct snd_pcm_substream *substream, int cmd)
214 {
215 struct snd_soc_pcm_runtime *rtd = snd_soc_substream_to_rtd(substream);
216 struct stm32_adfsdm_priv *priv =
217 snd_soc_dai_get_drvdata(snd_soc_rtd_to_cpu(rtd, 0));
218
219 switch (cmd) {
220 case SNDRV_PCM_TRIGGER_START:
221 case SNDRV_PCM_TRIGGER_RESUME:
222 priv->pos = 0;
223 return stm32_dfsdm_get_buff_cb(priv->iio_ch->indio_dev,
224 stm32_afsdm_pcm_cb, priv);
225 case SNDRV_PCM_TRIGGER_SUSPEND:
226 case SNDRV_PCM_TRIGGER_STOP:
227 return stm32_dfsdm_release_buff_cb(priv->iio_ch->indio_dev);
228 }
229
230 return -EINVAL;
231 }
232
233 static int stm32_adfsdm_pcm_open(struct snd_soc_component *component,
234 struct snd_pcm_substream *substream)
235 {
236 struct snd_soc_pcm_runtime *rtd = snd_soc_substream_to_rtd(substream);
237 struct stm32_adfsdm_priv *priv = snd_soc_dai_get_drvdata(snd_soc_rtd_to_cpu(rtd, 0));
238 int ret;
239
240 ret = snd_soc_set_runtime_hwparams(substream, &stm32_adfsdm_pcm_hw);
241 if (!ret)
242 priv->substream = substream;
243
244 return ret;
245 }
246
247 static int stm32_adfsdm_pcm_close(struct snd_soc_component *component,
248 struct snd_pcm_substream *substream)
249 {
250 struct snd_soc_pcm_runtime *rtd = snd_soc_substream_to_rtd(substream);
251 struct stm32_adfsdm_priv *priv =
252 snd_soc_dai_get_drvdata(snd_soc_rtd_to_cpu(rtd, 0));
253
254 priv->substream = NULL;
255
256 return 0;
257 }
258
259 static snd_pcm_uframes_t stm32_adfsdm_pcm_pointer(
260 struct snd_soc_component *component,
261 struct snd_pcm_substream *substream)
262 {
263 struct snd_soc_pcm_runtime *rtd = snd_soc_substream_to_rtd(substream);
264 struct stm32_adfsdm_priv *priv =
265 snd_soc_dai_get_drvdata(snd_soc_rtd_to_cpu(rtd, 0));
266
267 return bytes_to_frames(substream->runtime, priv->pos);
268 }
269
270 static int stm32_adfsdm_pcm_hw_params(struct snd_soc_component *component,
271 struct snd_pcm_substream *substream,
272 struct snd_pcm_hw_params *params)
273 {
274 struct snd_soc_pcm_runtime *rtd = snd_soc_substream_to_rtd(substream);
275 struct stm32_adfsdm_priv *priv =
276 snd_soc_dai_get_drvdata(snd_soc_rtd_to_cpu(rtd, 0));
277
278 priv->pcm_buff = substream->runtime->dma_area;
279
280 return iio_channel_cb_set_buffer_watermark(priv->iio_cb,
281 params_period_size(params));
282 }
283
284 static int stm32_adfsdm_pcm_new(struct snd_soc_component *component,
285 struct snd_soc_pcm_runtime *rtd)
286 {
287 struct snd_pcm *pcm = rtd->pcm;
288 struct stm32_adfsdm_priv *priv =
289 snd_soc_dai_get_drvdata(snd_soc_rtd_to_cpu(rtd, 0));
290 unsigned int size = DFSDM_MAX_PERIODS * DFSDM_MAX_PERIOD_SIZE;
291
292 snd_pcm_set_managed_buffer_all(pcm, SNDRV_DMA_TYPE_DEV,
293 priv->dev, size, size);
294 return 0;
295 }
296
297 static int stm32_adfsdm_dummy_cb(const void *data, void *private)
298 {
299 /*
300 * This dummy callback is requested by iio_channel_get_all_cb() API,
301 * but the stm32_dfsdm_get_buff_cb() API is used instead, to optimize
302 * DMA transfers.
303 */
304 return 0;
305 }
306
307 static void stm32_adfsdm_cleanup(void *data)
308 {
309 iio_channel_release_all_cb(data);
310 }
311
312 static struct snd_soc_component_driver stm32_adfsdm_soc_platform = {
313 .open = stm32_adfsdm_pcm_open,
314 .close = stm32_adfsdm_pcm_close,
315 .hw_params = stm32_adfsdm_pcm_hw_params,
316 .trigger = stm32_adfsdm_trigger,
317 .pointer = stm32_adfsdm_pcm_pointer,
318 .pcm_construct = stm32_adfsdm_pcm_new,
319 };
320
321 static const struct of_device_id stm32_adfsdm_of_match[] = {
322 {.compatible = "st,stm32h7-dfsdm-dai"},
323 {}
324 };
325 MODULE_DEVICE_TABLE(of, stm32_adfsdm_of_match);
326
327 static int stm32_adfsdm_probe(struct platform_device *pdev)
328 {
329 struct stm32_adfsdm_priv *priv;
330 struct snd_soc_component *component;
331 int ret;
332
333 priv = devm_kzalloc(&pdev->dev, sizeof(*priv), GFP_KERNEL);
334 if (!priv)
335 return -ENOMEM;
336
337 priv->dev = &pdev->dev;
338 priv->dai_drv = stm32_adfsdm_dai;
339 mutex_init(&priv->lock);
340
341 dev_set_drvdata(&pdev->dev, priv);
342
343 ret = devm_snd_soc_register_component(&pdev->dev,
344 &stm32_adfsdm_dai_component,
345 &priv->dai_drv, 1);
346 if (ret < 0)
347 return ret;
348
349 /* Associate iio channel */
350 priv->iio_ch = devm_iio_channel_get_all(&pdev->dev);
351 if (IS_ERR(priv->iio_ch))
352 return PTR_ERR(priv->iio_ch);
353
354 priv->iio_cb = iio_channel_get_all_cb(&pdev->dev, &stm32_adfsdm_dummy_cb, NULL);
355 if (IS_ERR(priv->iio_cb))
356 return PTR_ERR(priv->iio_cb);
357
358 ret = devm_add_action_or_reset(&pdev->dev, stm32_adfsdm_cleanup, priv->iio_cb);
359 if (ret < 0) {
360 dev_err(&pdev->dev, "Unable to add action\n");
361 return ret;
362 }
363
364 component = devm_kzalloc(&pdev->dev, sizeof(*component), GFP_KERNEL);
365 if (!component)
366 return -ENOMEM;
367
368 ret = snd_soc_component_initialize(component,
369 &stm32_adfsdm_soc_platform,
370 &pdev->dev);
371 if (ret < 0)
372 return ret;
373 #ifdef CONFIG_DEBUG_FS
374 component->debugfs_prefix = "pcm";
375 #endif
376
377 ret = snd_soc_add_component(component, NULL, 0);
378 if (ret < 0) {
379 dev_err(&pdev->dev, "%s: Failed to register PCM platform\n",
380 __func__);
381 return ret;
382 }
383
384 pm_runtime_enable(&pdev->dev);
385
386 return ret;
387 }
388
389 static void stm32_adfsdm_remove(struct platform_device *pdev)
390 {
391 snd_soc_unregister_component(&pdev->dev);
392 pm_runtime_disable(&pdev->dev);
393 }
394
395 static struct platform_driver stm32_adfsdm_driver = {
396 .driver = {
397 .name = STM32_ADFSDM_DRV_NAME,
398 .of_match_table = stm32_adfsdm_of_match,
399 },
400 .probe = stm32_adfsdm_probe,
401 .remove_new = stm32_adfsdm_remove,
402 };
403
404 module_platform_driver(stm32_adfsdm_driver);
405
406 MODULE_DESCRIPTION("stm32 DFSDM DAI driver");
407 MODULE_AUTHOR("Arnaud Pouliquen <arnaud.pouliquen@st.com>");
408 MODULE_LICENSE("GPL v2");
409 MODULE_ALIAS("platform:" STM32_ADFSDM_DRV_NAME);
410
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