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
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
28struct 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
45static 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
60static 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
73static 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
103out:
104	mutex_unlock(&priv->lock);
105
106	return ret;
107}
108
109static 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), "%d\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
131static 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
137static 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
150static const struct snd_soc_component_driver stm32_adfsdm_dai_component = {
151	.name = "stm32_dfsdm_audio",
152};
153
154static void stm32_memcpy_32to16(void *dest, const void *src, size_t n)
155{
156	unsigned int i = 0;
157	u16 *d = (u16 *)dest, *s = (u16 *)src;
158
159	s++;
160	for (i = n >> 1; i > 0; i--) {
161		*d++ = *s++;
162		s++;
163	}
164}
165
166static int stm32_afsdm_pcm_cb(const void *data, size_t size, void *private)
167{
168	struct stm32_adfsdm_priv *priv = private;
169	struct snd_soc_pcm_runtime *rtd = asoc_substream_to_rtd(priv->substream);
170	u8 *pcm_buff = priv->pcm_buff;
171	u8 *src_buff = (u8 *)data;
172	unsigned int old_pos = priv->pos;
173	size_t buff_size = snd_pcm_lib_buffer_bytes(priv->substream);
174	size_t period_size = snd_pcm_lib_period_bytes(priv->substream);
175	size_t cur_size, src_size = size;
176	snd_pcm_format_t format = priv->substream->runtime->format;
177
178	if (format == SNDRV_PCM_FORMAT_S16_LE)
179		src_size >>= 1;
180	cur_size = src_size;
181
182	dev_dbg(rtd->dev, "%s: buff_add :%pK, pos = %d, size = %zu\n",
183		__func__, &pcm_buff[priv->pos], priv->pos, src_size);
184
185	if ((priv->pos + src_size) > buff_size) {
186		if (format == SNDRV_PCM_FORMAT_S16_LE)
187			stm32_memcpy_32to16(&pcm_buff[priv->pos], src_buff,
188					    buff_size - priv->pos);
189		else
190			memcpy(&pcm_buff[priv->pos], src_buff,
191			       buff_size - priv->pos);
192		cur_size -= buff_size - priv->pos;
193		priv->pos = 0;
194	}
195
196	if (format == SNDRV_PCM_FORMAT_S16_LE)
197		stm32_memcpy_32to16(&pcm_buff[priv->pos],
198				    &src_buff[src_size - cur_size], cur_size);
199	else
200		memcpy(&pcm_buff[priv->pos], &src_buff[src_size - cur_size],
201		       cur_size);
202
203	priv->pos = (priv->pos + cur_size) % buff_size;
204
205	if (cur_size != src_size || (old_pos && (old_pos % period_size < size)))
206		snd_pcm_period_elapsed(priv->substream);
207
208	return 0;
209}
210
211static int stm32_adfsdm_trigger(struct snd_soc_component *component,
212				struct snd_pcm_substream *substream, int cmd)
213{
214	struct snd_soc_pcm_runtime *rtd = asoc_substream_to_rtd(substream);
215	struct stm32_adfsdm_priv *priv =
216		snd_soc_dai_get_drvdata(asoc_rtd_to_cpu(rtd, 0));
217
218	switch (cmd) {
219	case SNDRV_PCM_TRIGGER_START:
220	case SNDRV_PCM_TRIGGER_RESUME:
221		priv->pos = 0;
222		return stm32_dfsdm_get_buff_cb(priv->iio_ch->indio_dev,
223					       stm32_afsdm_pcm_cb, priv);
224	case SNDRV_PCM_TRIGGER_SUSPEND:
225	case SNDRV_PCM_TRIGGER_STOP:
226		return stm32_dfsdm_release_buff_cb(priv->iio_ch->indio_dev);
227	}
228
229	return -EINVAL;
230}
231
232static int stm32_adfsdm_pcm_open(struct snd_soc_component *component,
233				 struct snd_pcm_substream *substream)
234{
235	struct snd_soc_pcm_runtime *rtd = asoc_substream_to_rtd(substream);
236	struct stm32_adfsdm_priv *priv = snd_soc_dai_get_drvdata(asoc_rtd_to_cpu(rtd, 0));
237	int ret;
238
239	ret =  snd_soc_set_runtime_hwparams(substream, &stm32_adfsdm_pcm_hw);
240	if (!ret)
241		priv->substream = substream;
242
243	return ret;
244}
245
246static int stm32_adfsdm_pcm_close(struct snd_soc_component *component,
247				  struct snd_pcm_substream *substream)
248{
249	struct snd_soc_pcm_runtime *rtd = asoc_substream_to_rtd(substream);
250	struct stm32_adfsdm_priv *priv =
251		snd_soc_dai_get_drvdata(asoc_rtd_to_cpu(rtd, 0));
252
253	priv->substream = NULL;
254
255	return 0;
256}
257
258static snd_pcm_uframes_t stm32_adfsdm_pcm_pointer(
259					    struct snd_soc_component *component,
260					    struct snd_pcm_substream *substream)
261{
262	struct snd_soc_pcm_runtime *rtd = asoc_substream_to_rtd(substream);
263	struct stm32_adfsdm_priv *priv =
264		snd_soc_dai_get_drvdata(asoc_rtd_to_cpu(rtd, 0));
265
266	return bytes_to_frames(substream->runtime, priv->pos);
267}
268
269static int stm32_adfsdm_pcm_hw_params(struct snd_soc_component *component,
270				      struct snd_pcm_substream *substream,
271				      struct snd_pcm_hw_params *params)
272{
273	struct snd_soc_pcm_runtime *rtd = asoc_substream_to_rtd(substream);
274	struct stm32_adfsdm_priv *priv =
275		snd_soc_dai_get_drvdata(asoc_rtd_to_cpu(rtd, 0));
276
277	priv->pcm_buff = substream->runtime->dma_area;
278
279	return iio_channel_cb_set_buffer_watermark(priv->iio_cb,
280						   params_period_size(params));
281}
282
283static int stm32_adfsdm_pcm_new(struct snd_soc_component *component,
284				struct snd_soc_pcm_runtime *rtd)
285{
286	struct snd_pcm *pcm = rtd->pcm;
287	struct stm32_adfsdm_priv *priv =
288		snd_soc_dai_get_drvdata(asoc_rtd_to_cpu(rtd, 0));
289	unsigned int size = DFSDM_MAX_PERIODS * DFSDM_MAX_PERIOD_SIZE;
290
291	snd_pcm_set_managed_buffer_all(pcm, SNDRV_DMA_TYPE_DEV,
292				       priv->dev, size, size);
293	return 0;
294}
295
296static struct snd_soc_component_driver stm32_adfsdm_soc_platform = {
297	.open		= stm32_adfsdm_pcm_open,
298	.close		= stm32_adfsdm_pcm_close,
299	.hw_params	= stm32_adfsdm_pcm_hw_params,
300	.trigger	= stm32_adfsdm_trigger,
301	.pointer	= stm32_adfsdm_pcm_pointer,
302	.pcm_construct	= stm32_adfsdm_pcm_new,
303};
304
305static const struct of_device_id stm32_adfsdm_of_match[] = {
306	{.compatible = "st,stm32h7-dfsdm-dai"},
307	{}
308};
309MODULE_DEVICE_TABLE(of, stm32_adfsdm_of_match);
310
311static int stm32_adfsdm_probe(struct platform_device *pdev)
312{
313	struct stm32_adfsdm_priv *priv;
314	struct snd_soc_component *component;
315	int ret;
316
317	priv = devm_kzalloc(&pdev->dev, sizeof(*priv), GFP_KERNEL);
318	if (!priv)
319		return -ENOMEM;
320
321	priv->dev = &pdev->dev;
322	priv->dai_drv = stm32_adfsdm_dai;
323	mutex_init(&priv->lock);
324
325	dev_set_drvdata(&pdev->dev, priv);
326
327	ret = devm_snd_soc_register_component(&pdev->dev,
328					      &stm32_adfsdm_dai_component,
329					      &priv->dai_drv, 1);
330	if (ret < 0)
331		return ret;
332
333	/* Associate iio channel */
334	priv->iio_ch  = devm_iio_channel_get_all(&pdev->dev);
335	if (IS_ERR(priv->iio_ch))
336		return PTR_ERR(priv->iio_ch);
337
338	priv->iio_cb = iio_channel_get_all_cb(&pdev->dev, NULL, NULL);
339	if (IS_ERR(priv->iio_cb))
340		return PTR_ERR(priv->iio_cb);
341
342	component = devm_kzalloc(&pdev->dev, sizeof(*component), GFP_KERNEL);
343	if (!component)
344		return -ENOMEM;
345
346	ret = snd_soc_component_initialize(component,
347					   &stm32_adfsdm_soc_platform,
348					   &pdev->dev);
349	if (ret < 0)
350		return ret;
351#ifdef CONFIG_DEBUG_FS
352	component->debugfs_prefix = "pcm";
353#endif
354
355	ret = snd_soc_add_component(component, NULL, 0);
356	if (ret < 0)
357		dev_err(&pdev->dev, "%s: Failed to register PCM platform\n",
358			__func__);
359
360	return ret;
361}
362
363static int stm32_adfsdm_remove(struct platform_device *pdev)
364{
365	snd_soc_unregister_component(&pdev->dev);
366
367	return 0;
368}
369
370static struct platform_driver stm32_adfsdm_driver = {
371	.driver = {
372		   .name = STM32_ADFSDM_DRV_NAME,
373		   .of_match_table = stm32_adfsdm_of_match,
374		   },
375	.probe = stm32_adfsdm_probe,
376	.remove = stm32_adfsdm_remove,
377};
378
379module_platform_driver(stm32_adfsdm_driver);
380
381MODULE_DESCRIPTION("stm32 DFSDM DAI driver");
382MODULE_AUTHOR("Arnaud Pouliquen <arnaud.pouliquen@st.com>");
383MODULE_LICENSE("GPL v2");
384MODULE_ALIAS("platform:" STM32_ADFSDM_DRV_NAME);
385