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 
stm32_adfsdm_shutdown(struct snd_pcm_substream * substream,struct snd_soc_dai * dai)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 
stm32_adfsdm_dai_prepare(struct snd_pcm_substream * substream,struct snd_soc_dai * dai)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 
stm32_adfsdm_set_sysclk(struct snd_soc_dai * dai,int clk_id,unsigned int freq,int dir)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 
stm32_memcpy_32to16(void * dest,const void * src,size_t n)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 
stm32_afsdm_pcm_cb(const void * data,size_t size,void * private)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 = asoc_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 
stm32_adfsdm_trigger(struct snd_soc_component * component,struct snd_pcm_substream * substream,int cmd)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 = asoc_substream_to_rtd(substream);
216 	struct stm32_adfsdm_priv *priv =
217 		snd_soc_dai_get_drvdata(asoc_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 
stm32_adfsdm_pcm_open(struct snd_soc_component * component,struct snd_pcm_substream * substream)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 = asoc_substream_to_rtd(substream);
237 	struct stm32_adfsdm_priv *priv = snd_soc_dai_get_drvdata(asoc_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 
stm32_adfsdm_pcm_close(struct snd_soc_component * component,struct snd_pcm_substream * substream)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 = asoc_substream_to_rtd(substream);
251 	struct stm32_adfsdm_priv *priv =
252 		snd_soc_dai_get_drvdata(asoc_rtd_to_cpu(rtd, 0));
253 
254 	priv->substream = NULL;
255 
256 	return 0;
257 }
258 
stm32_adfsdm_pcm_pointer(struct snd_soc_component * component,struct snd_pcm_substream * substream)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 = asoc_substream_to_rtd(substream);
264 	struct stm32_adfsdm_priv *priv =
265 		snd_soc_dai_get_drvdata(asoc_rtd_to_cpu(rtd, 0));
266 
267 	return bytes_to_frames(substream->runtime, priv->pos);
268 }
269 
stm32_adfsdm_pcm_hw_params(struct snd_soc_component * component,struct snd_pcm_substream * substream,struct snd_pcm_hw_params * params)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 = asoc_substream_to_rtd(substream);
275 	struct stm32_adfsdm_priv *priv =
276 		snd_soc_dai_get_drvdata(asoc_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 
stm32_adfsdm_pcm_new(struct snd_soc_component * component,struct snd_soc_pcm_runtime * rtd)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(asoc_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 
stm32_adfsdm_dummy_cb(const void * data,void * private)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 
stm32_adfsdm_cleanup(void * data)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 
stm32_adfsdm_probe(struct platform_device * pdev)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 
stm32_adfsdm_remove(struct platform_device * pdev)389 static int stm32_adfsdm_remove(struct platform_device *pdev)
390 {
391 	snd_soc_unregister_component(&pdev->dev);
392 	pm_runtime_disable(&pdev->dev);
393 
394 	return 0;
395 }
396 
397 static struct platform_driver stm32_adfsdm_driver = {
398 	.driver = {
399 		   .name = STM32_ADFSDM_DRV_NAME,
400 		   .of_match_table = stm32_adfsdm_of_match,
401 		   },
402 	.probe = stm32_adfsdm_probe,
403 	.remove = stm32_adfsdm_remove,
404 };
405 
406 module_platform_driver(stm32_adfsdm_driver);
407 
408 MODULE_DESCRIPTION("stm32 DFSDM DAI driver");
409 MODULE_AUTHOR("Arnaud Pouliquen <arnaud.pouliquen@st.com>");
410 MODULE_LICENSE("GPL v2");
411 MODULE_ALIAS("platform:" STM32_ADFSDM_DRV_NAME);
412