xref: /linux/sound/soc/atmel/mchp-pdmc.c (revision c532de5a67a70f8533d495f8f2aaa9a0491c3ad0)
1 // SPDX-License-Identifier: GPL-2.0
2 //
3 // Driver for Microchip Pulse Density Microphone Controller (PDMC) interfaces
4 //
5 // Copyright (C) 2019-2022 Microchip Technology Inc. and its subsidiaries
6 //
7 // Author: Codrin Ciubotariu <codrin.ciubotariu@microchip.com>
8 
9 #include <dt-bindings/sound/microchip,pdmc.h>
10 
11 #include <linux/bitfield.h>
12 #include <linux/clk.h>
13 #include <linux/module.h>
14 #include <linux/of.h>
15 #include <linux/pm_runtime.h>
16 #include <linux/regmap.h>
17 
18 #include <sound/core.h>
19 #include <sound/dmaengine_pcm.h>
20 #include <sound/pcm_params.h>
21 #include <sound/tlv.h>
22 
23 /*
24  * ---- PDMC Register map ----
25  */
26 #define MCHP_PDMC_CR			0x00	/* Control Register */
27 #define MCHP_PDMC_MR			0x04	/* Mode Register */
28 #define MCHP_PDMC_CFGR			0x08	/* Configuration Register */
29 #define MCHP_PDMC_RHR			0x0C	/* Receive Holding Register */
30 #define MCHP_PDMC_IER			0x14	/* Interrupt Enable Register */
31 #define MCHP_PDMC_IDR			0x18	/* Interrupt Disable Register */
32 #define MCHP_PDMC_IMR			0x1C	/* Interrupt Mask Register */
33 #define MCHP_PDMC_ISR			0x20	/* Interrupt Status Register */
34 #define MCHP_PDMC_VER			0x50	/* Version Register */
35 
36 /*
37  * ---- Control Register (Write-only) ----
38  */
39 #define MCHP_PDMC_CR_SWRST		BIT(0)	/* Software Reset */
40 
41 /*
42  * ---- Mode Register (Read/Write) ----
43  */
44 #define MCHP_PDMC_MR_PDMCEN_MASK	GENMASK(3, 0)
45 #define MCHP_PDMC_MR_PDMCEN(ch)		(BIT(ch) & MCHP_PDMC_MR_PDMCEN_MASK)
46 
47 #define MCHP_PDMC_MR_OSR_MASK		GENMASK(17, 16)
48 #define MCHP_PDMC_MR_OSR64		(1 << 16)
49 #define MCHP_PDMC_MR_OSR128		(2 << 16)
50 #define MCHP_PDMC_MR_OSR256		(3 << 16)
51 
52 #define MCHP_PDMC_MR_SINCORDER_MASK	GENMASK(23, 20)
53 
54 #define MCHP_PDMC_MR_SINC_OSR_MASK	GENMASK(27, 24)
55 #define MCHP_PDMC_MR_SINC_OSR_DIS	(0 << 24)
56 #define MCHP_PDMC_MR_SINC_OSR_8		(1 << 24)
57 #define MCHP_PDMC_MR_SINC_OSR_16	(2 << 24)
58 #define MCHP_PDMC_MR_SINC_OSR_32	(3 << 24)
59 #define MCHP_PDMC_MR_SINC_OSR_64	(4 << 24)
60 #define MCHP_PDMC_MR_SINC_OSR_128	(5 << 24)
61 #define MCHP_PDMC_MR_SINC_OSR_256	(6 << 24)
62 
63 #define MCHP_PDMC_MR_CHUNK_MASK		GENMASK(31, 28)
64 
65 /*
66  * ---- Configuration Register (Read/Write) ----
67  */
68 #define MCHP_PDMC_CFGR_BSSEL_MASK	(BIT(0) | BIT(2) | BIT(4) | BIT(6))
69 #define MCHP_PDMC_CFGR_BSSEL(ch)	BIT((ch) * 2)
70 
71 #define MCHP_PDMC_CFGR_PDMSEL_MASK	(BIT(16) | BIT(18) | BIT(20) | BIT(22))
72 #define MCHP_PDMC_CFGR_PDMSEL(ch)	BIT((ch) * 2 + 16)
73 
74 /*
75  * ---- Interrupt Enable/Disable/Mask/Status Registers ----
76  */
77 #define MCHP_PDMC_IR_RXRDY		BIT(0)
78 #define MCHP_PDMC_IR_RXEMPTY		BIT(1)
79 #define MCHP_PDMC_IR_RXFULL		BIT(2)
80 #define MCHP_PDMC_IR_RXCHUNK		BIT(3)
81 #define MCHP_PDMC_IR_RXUDR		BIT(4)
82 #define MCHP_PDMC_IR_RXOVR		BIT(5)
83 
84 /*
85  * ---- Version Register (Read-only) ----
86  */
87 #define MCHP_PDMC_VER_VERSION		GENMASK(11, 0)
88 
89 #define MCHP_PDMC_MAX_CHANNELS		4
90 #define MCHP_PDMC_DS_NO			2
91 #define MCHP_PDMC_EDGE_NO		2
92 
93 /*
94  * ---- DMA chunk size allowed ----
95  */
96 #define MCHP_PDMC_DMA_8_WORD_CHUNK			8
97 #define MCHP_PDMC_DMA_4_WORD_CHUNK			4
98 #define MCHP_PDMC_DMA_2_WORD_CHUNK			2
99 #define MCHP_PDMC_DMA_1_WORD_CHUNK			1
100 #define DMA_BURST_ALIGNED(_p, _s, _w)		!(_p % (_s * _w))
101 
102 struct mic_map {
103 	int ds_pos;
104 	int clk_edge;
105 };
106 
107 struct mchp_pdmc_chmap {
108 	struct snd_pcm_chmap_elem *chmap;
109 	struct mchp_pdmc *dd;
110 	struct snd_pcm *pcm;
111 	struct snd_kcontrol *kctl;
112 };
113 
114 struct mchp_pdmc {
115 	struct mic_map channel_mic_map[MCHP_PDMC_MAX_CHANNELS];
116 	struct device *dev;
117 	struct snd_dmaengine_dai_dma_data addr;
118 	struct regmap *regmap;
119 	struct clk *pclk;
120 	struct clk *gclk;
121 	u32 pdmcen;
122 	u32 suspend_irq;
123 	u32 startup_delay_us;
124 	int mic_no;
125 	int sinc_order;
126 	bool audio_filter_en;
127 	atomic_t busy_stream;
128 };
129 
130 static const char *const mchp_pdmc_sinc_filter_order_text[] = {
131 	"1", "2", "3", "4", "5"
132 };
133 
134 static const unsigned int mchp_pdmc_sinc_filter_order_values[] = {
135 	1, 2, 3, 4, 5,
136 };
137 
138 static const struct soc_enum mchp_pdmc_sinc_filter_order_enum = {
139 	.items = ARRAY_SIZE(mchp_pdmc_sinc_filter_order_text),
140 	.texts = mchp_pdmc_sinc_filter_order_text,
141 	.values = mchp_pdmc_sinc_filter_order_values,
142 };
143 
144 static int mchp_pdmc_sinc_order_get(struct snd_kcontrol *kcontrol,
145 				    struct snd_ctl_elem_value *uvalue)
146 {
147 	struct snd_soc_component *component = snd_kcontrol_chip(kcontrol);
148 	struct mchp_pdmc *dd = snd_soc_component_get_drvdata(component);
149 	struct soc_enum *e = (struct soc_enum *)kcontrol->private_value;
150 	unsigned int item;
151 
152 	item = snd_soc_enum_val_to_item(e, dd->sinc_order);
153 	uvalue->value.enumerated.item[0] = item;
154 
155 	return 0;
156 }
157 
158 static int mchp_pdmc_sinc_order_put(struct snd_kcontrol *kcontrol,
159 				    struct snd_ctl_elem_value *uvalue)
160 {
161 	struct snd_soc_component *component = snd_kcontrol_chip(kcontrol);
162 	struct mchp_pdmc *dd = snd_soc_component_get_drvdata(component);
163 	struct soc_enum *e = (struct soc_enum *)kcontrol->private_value;
164 	unsigned int *item = uvalue->value.enumerated.item;
165 	unsigned int val;
166 
167 	if (item[0] >= e->items)
168 		return -EINVAL;
169 
170 	val = snd_soc_enum_item_to_val(e, item[0]) << e->shift_l;
171 
172 	if (atomic_read(&dd->busy_stream))
173 		return -EBUSY;
174 
175 	if (val == dd->sinc_order)
176 		return 0;
177 
178 	dd->sinc_order = val;
179 
180 	return 1;
181 }
182 
183 static int mchp_pdmc_af_get(struct snd_kcontrol *kcontrol,
184 			    struct snd_ctl_elem_value *uvalue)
185 {
186 	struct snd_soc_component *component = snd_kcontrol_chip(kcontrol);
187 	struct mchp_pdmc *dd = snd_soc_component_get_drvdata(component);
188 
189 	uvalue->value.integer.value[0] = !!dd->audio_filter_en;
190 
191 	return 0;
192 }
193 
194 static int mchp_pdmc_af_put(struct snd_kcontrol *kcontrol,
195 			    struct snd_ctl_elem_value *uvalue)
196 {
197 	struct snd_soc_component *component = snd_kcontrol_chip(kcontrol);
198 	struct mchp_pdmc *dd = snd_soc_component_get_drvdata(component);
199 	bool af = uvalue->value.integer.value[0] ? true : false;
200 
201 	if (atomic_read(&dd->busy_stream))
202 		return -EBUSY;
203 
204 	if (dd->audio_filter_en == af)
205 		return 0;
206 
207 	dd->audio_filter_en = af;
208 
209 	return 1;
210 }
211 
212 static int mchp_pdmc_chmap_ctl_info(struct snd_kcontrol *kcontrol, struct snd_ctl_elem_info *uinfo)
213 {
214 	struct mchp_pdmc_chmap *info = snd_kcontrol_chip(kcontrol);
215 
216 	uinfo->type = SNDRV_CTL_ELEM_TYPE_INTEGER;
217 	uinfo->count = info->dd->mic_no;
218 	uinfo->value.integer.min = 0;
219 	uinfo->value.integer.max = SNDRV_CHMAP_RR; /* maxmimum 4 channels */
220 	return 0;
221 }
222 
223 static inline struct snd_pcm_substream *
224 mchp_pdmc_chmap_substream(struct mchp_pdmc_chmap *info, unsigned int idx)
225 {
226 	struct snd_pcm_substream *s;
227 
228 	for (s = info->pcm->streams[SNDRV_PCM_STREAM_CAPTURE].substream; s; s = s->next)
229 		if (s->number == idx)
230 			return s;
231 	return NULL;
232 }
233 
234 static struct snd_pcm_chmap_elem *mchp_pdmc_chmap_get(struct snd_pcm_substream *substream,
235 						      struct mchp_pdmc_chmap *ch_info)
236 {
237 	struct snd_pcm_chmap_elem *map;
238 
239 	for (map = ch_info->chmap; map->channels; map++) {
240 		if (map->channels == substream->runtime->channels)
241 			return map;
242 	}
243 	return NULL;
244 }
245 
246 static int mchp_pdmc_chmap_ctl_get(struct snd_kcontrol *kcontrol,
247 				   struct snd_ctl_elem_value *ucontrol)
248 {
249 	struct mchp_pdmc_chmap *info = snd_kcontrol_chip(kcontrol);
250 	struct mchp_pdmc *dd = info->dd;
251 	unsigned int idx = snd_ctl_get_ioffidx(kcontrol, &ucontrol->id);
252 	struct snd_pcm_substream *substream;
253 	const struct snd_pcm_chmap_elem *map;
254 	int i;
255 	u32 cfgr_val = 0;
256 
257 	if (!info->chmap)
258 		return -EINVAL;
259 	substream = mchp_pdmc_chmap_substream(info, idx);
260 	if (!substream)
261 		return -ENODEV;
262 	memset(ucontrol->value.integer.value, 0, sizeof(long) * info->dd->mic_no);
263 	if (!substream->runtime)
264 		return 0; /* no channels set */
265 
266 	map = mchp_pdmc_chmap_get(substream, info);
267 	if (!map)
268 		return -EINVAL;
269 
270 	for (i = 0; i < map->channels; i++) {
271 		int map_idx = map->channels == 1 ? map->map[i] - SNDRV_CHMAP_MONO :
272 						   map->map[i] - SNDRV_CHMAP_FL;
273 
274 		/* make sure the reported channel map is the real one, so write the map */
275 		if (dd->channel_mic_map[map_idx].ds_pos)
276 			cfgr_val |= MCHP_PDMC_CFGR_PDMSEL(i);
277 		if (dd->channel_mic_map[map_idx].clk_edge)
278 			cfgr_val |= MCHP_PDMC_CFGR_BSSEL(i);
279 
280 		ucontrol->value.integer.value[i] = map->map[i];
281 	}
282 
283 	regmap_write(dd->regmap, MCHP_PDMC_CFGR, cfgr_val);
284 
285 	return 0;
286 }
287 
288 static int mchp_pdmc_chmap_ctl_put(struct snd_kcontrol *kcontrol,
289 				   struct snd_ctl_elem_value *ucontrol)
290 {
291 	struct mchp_pdmc_chmap *info = snd_kcontrol_chip(kcontrol);
292 	struct mchp_pdmc *dd = info->dd;
293 	unsigned int idx = snd_ctl_get_ioffidx(kcontrol, &ucontrol->id);
294 	struct snd_pcm_substream *substream;
295 	struct snd_pcm_chmap_elem *map;
296 	u32 cfgr_val = 0;
297 	int i;
298 
299 	if (!info->chmap)
300 		return -EINVAL;
301 	substream = mchp_pdmc_chmap_substream(info, idx);
302 	if (!substream)
303 		return -ENODEV;
304 
305 	if (!substream->runtime)
306 		return 0; /* just for avoiding error from alsactl restore */
307 
308 	map = mchp_pdmc_chmap_get(substream, info);
309 	if (!map)
310 		return -EINVAL;
311 
312 	for (i = 0; i < map->channels; i++) {
313 		int map_idx;
314 
315 		map->map[i] = ucontrol->value.integer.value[i];
316 		map_idx = map->channels == 1 ? map->map[i] - SNDRV_CHMAP_MONO :
317 					       map->map[i] - SNDRV_CHMAP_FL;
318 
319 		/* configure IP for the desired channel map */
320 		if (dd->channel_mic_map[map_idx].ds_pos)
321 			cfgr_val |= MCHP_PDMC_CFGR_PDMSEL(i);
322 		if (dd->channel_mic_map[map_idx].clk_edge)
323 			cfgr_val |= MCHP_PDMC_CFGR_BSSEL(i);
324 	}
325 
326 	regmap_write(dd->regmap, MCHP_PDMC_CFGR, cfgr_val);
327 
328 	return 0;
329 }
330 
331 static void mchp_pdmc_chmap_ctl_private_free(struct snd_kcontrol *kcontrol)
332 {
333 	struct mchp_pdmc_chmap *info = snd_kcontrol_chip(kcontrol);
334 
335 	info->pcm->streams[SNDRV_PCM_STREAM_CAPTURE].chmap_kctl = NULL;
336 	kfree(info);
337 }
338 
339 static int mchp_pdmc_chmap_ctl_tlv(struct snd_kcontrol *kcontrol, int op_flag,
340 				   unsigned int size, unsigned int __user *tlv)
341 {
342 	struct mchp_pdmc_chmap *info = snd_kcontrol_chip(kcontrol);
343 	const struct snd_pcm_chmap_elem *map;
344 	unsigned int __user *dst;
345 	int c, count = 0;
346 
347 	if (!info->chmap)
348 		return -EINVAL;
349 	if (size < 8)
350 		return -ENOMEM;
351 	if (put_user(SNDRV_CTL_TLVT_CONTAINER, tlv))
352 		return -EFAULT;
353 	size -= 8;
354 	dst = tlv + 2;
355 	for (map = info->chmap; map->channels; map++) {
356 		int chs_bytes = map->channels * 4;
357 
358 		if (size < 8)
359 			return -ENOMEM;
360 		if (put_user(SNDRV_CTL_TLVT_CHMAP_VAR, dst) ||
361 		    put_user(chs_bytes, dst + 1))
362 			return -EFAULT;
363 		dst += 2;
364 		size -= 8;
365 		count += 8;
366 		if (size < chs_bytes)
367 			return -ENOMEM;
368 		size -= chs_bytes;
369 		count += chs_bytes;
370 		for (c = 0; c < map->channels; c++) {
371 			if (put_user(map->map[c], dst))
372 				return -EFAULT;
373 			dst++;
374 		}
375 	}
376 	if (put_user(count, tlv + 1))
377 		return -EFAULT;
378 	return 0;
379 }
380 
381 static const struct snd_kcontrol_new mchp_pdmc_snd_controls[] = {
382 	SOC_SINGLE_BOOL_EXT("Audio Filter", 0, &mchp_pdmc_af_get, &mchp_pdmc_af_put),
383 	{
384 		.iface = SNDRV_CTL_ELEM_IFACE_MIXER,
385 		.name = "SINC Filter Order",
386 		.info = snd_soc_info_enum_double,
387 		.get = mchp_pdmc_sinc_order_get,
388 		.put = mchp_pdmc_sinc_order_put,
389 		.private_value = (unsigned long)&mchp_pdmc_sinc_filter_order_enum,
390 	},
391 };
392 
393 static const struct snd_soc_component_driver mchp_pdmc_dai_component = {
394 	.name = "mchp-pdmc",
395 	.controls = mchp_pdmc_snd_controls,
396 	.num_controls = ARRAY_SIZE(mchp_pdmc_snd_controls),
397 };
398 
399 static const unsigned int mchp_pdmc_1mic[] = {1};
400 static const unsigned int mchp_pdmc_2mic[] = {1, 2};
401 static const unsigned int mchp_pdmc_3mic[] = {1, 2, 3};
402 static const unsigned int mchp_pdmc_4mic[] = {1, 2, 3, 4};
403 
404 static const struct snd_pcm_hw_constraint_list mchp_pdmc_chan_constr[] = {
405 	{
406 		.list = mchp_pdmc_1mic,
407 		.count = ARRAY_SIZE(mchp_pdmc_1mic),
408 	},
409 	{
410 		.list = mchp_pdmc_2mic,
411 		.count = ARRAY_SIZE(mchp_pdmc_2mic),
412 	},
413 	{
414 		.list = mchp_pdmc_3mic,
415 		.count = ARRAY_SIZE(mchp_pdmc_3mic),
416 	},
417 	{
418 		.list = mchp_pdmc_4mic,
419 		.count = ARRAY_SIZE(mchp_pdmc_4mic),
420 	},
421 };
422 
423 static int mchp_pdmc_startup(struct snd_pcm_substream *substream,
424 			     struct snd_soc_dai *dai)
425 {
426 	struct mchp_pdmc *dd = snd_soc_dai_get_drvdata(dai);
427 
428 	regmap_write(dd->regmap, MCHP_PDMC_CR, MCHP_PDMC_CR_SWRST);
429 
430 	snd_pcm_hw_constraint_list(substream->runtime, 0, SNDRV_PCM_HW_PARAM_CHANNELS,
431 				   &mchp_pdmc_chan_constr[dd->mic_no - 1]);
432 
433 	return 0;
434 }
435 
436 static int mchp_pdmc_dai_probe(struct snd_soc_dai *dai)
437 {
438 	struct mchp_pdmc *dd = snd_soc_dai_get_drvdata(dai);
439 
440 	snd_soc_dai_init_dma_data(dai, NULL, &dd->addr);
441 
442 	return 0;
443 }
444 
445 static int mchp_pdmc_set_fmt(struct snd_soc_dai *dai, unsigned int fmt)
446 {
447 	unsigned int fmt_master = fmt & SND_SOC_DAIFMT_MASTER_MASK;
448 	unsigned int fmt_format = fmt & SND_SOC_DAIFMT_FORMAT_MASK;
449 
450 	/* IP needs to be bitclock master */
451 	if (fmt_master != SND_SOC_DAIFMT_BP_FP &&
452 	    fmt_master != SND_SOC_DAIFMT_BP_FC)
453 		return -EINVAL;
454 
455 	/* IP supports only PDM interface */
456 	if (fmt_format != SND_SOC_DAIFMT_PDM)
457 		return -EINVAL;
458 
459 	return 0;
460 }
461 
462 static u32 mchp_pdmc_mr_set_osr(int audio_filter_en, unsigned int osr)
463 {
464 	if (audio_filter_en) {
465 		switch (osr) {
466 		case 64:
467 			return MCHP_PDMC_MR_OSR64;
468 		case 128:
469 			return MCHP_PDMC_MR_OSR128;
470 		case 256:
471 			return MCHP_PDMC_MR_OSR256;
472 		}
473 	} else {
474 		switch (osr) {
475 		case 8:
476 			return MCHP_PDMC_MR_SINC_OSR_8;
477 		case 16:
478 			return MCHP_PDMC_MR_SINC_OSR_16;
479 		case 32:
480 			return MCHP_PDMC_MR_SINC_OSR_32;
481 		case 64:
482 			return MCHP_PDMC_MR_SINC_OSR_64;
483 		case 128:
484 			return MCHP_PDMC_MR_SINC_OSR_128;
485 		case 256:
486 			return MCHP_PDMC_MR_SINC_OSR_256;
487 		}
488 	}
489 	return 0;
490 }
491 
492 static inline int mchp_pdmc_period_to_maxburst(int period_size, int sample_size)
493 {
494 	int p_size = period_size;
495 	int s_size = sample_size;
496 
497 	if (DMA_BURST_ALIGNED(p_size, s_size, MCHP_PDMC_DMA_8_WORD_CHUNK))
498 		return MCHP_PDMC_DMA_8_WORD_CHUNK;
499 	if (DMA_BURST_ALIGNED(p_size, s_size, MCHP_PDMC_DMA_4_WORD_CHUNK))
500 		return MCHP_PDMC_DMA_4_WORD_CHUNK;
501 	if (DMA_BURST_ALIGNED(p_size, s_size, MCHP_PDMC_DMA_2_WORD_CHUNK))
502 		return MCHP_PDMC_DMA_2_WORD_CHUNK;
503 	return MCHP_PDMC_DMA_1_WORD_CHUNK;
504 }
505 
506 static struct snd_pcm_chmap_elem mchp_pdmc_std_chmaps[] = {
507 	{ .channels = 1,
508 	  .map = { SNDRV_CHMAP_MONO } },
509 	{ .channels = 2,
510 	  .map = { SNDRV_CHMAP_FL, SNDRV_CHMAP_FR } },
511 	{ .channels = 3,
512 	  .map = { SNDRV_CHMAP_FL, SNDRV_CHMAP_FR,
513 		   SNDRV_CHMAP_RL } },
514 	{ .channels = 4,
515 	  .map = { SNDRV_CHMAP_FL, SNDRV_CHMAP_FR,
516 		   SNDRV_CHMAP_RL, SNDRV_CHMAP_RR } },
517 	{ }
518 };
519 
520 static int mchp_pdmc_hw_params(struct snd_pcm_substream *substream,
521 			       struct snd_pcm_hw_params *params,
522 			       struct snd_soc_dai *dai)
523 {
524 	struct mchp_pdmc *dd = snd_soc_dai_get_drvdata(dai);
525 	struct snd_soc_component *comp = dai->component;
526 	unsigned long gclk_rate = 0;
527 	unsigned long best_diff_rate = ~0UL;
528 	unsigned int channels = params_channels(params);
529 	unsigned int osr = 0, osr_start;
530 	unsigned int fs = params_rate(params);
531 	int sample_bytes = params_physical_width(params) / 8;
532 	int period_bytes = params_period_size(params) *
533 		params_channels(params) * sample_bytes;
534 	int maxburst;
535 	u32 mr_val = 0;
536 	u32 cfgr_val = 0;
537 	int i;
538 	int ret;
539 
540 	dev_dbg(comp->dev, "%s() rate=%u format=%#x width=%u channels=%u period_bytes=%d\n",
541 		__func__, params_rate(params), params_format(params),
542 		params_width(params), params_channels(params), period_bytes);
543 
544 	if (channels > dd->mic_no) {
545 		dev_err(comp->dev, "more channels %u than microphones %d\n",
546 			channels, dd->mic_no);
547 		return -EINVAL;
548 	}
549 
550 	dd->pdmcen = 0;
551 	for (i = 0; i < channels; i++) {
552 		dd->pdmcen |= MCHP_PDMC_MR_PDMCEN(i);
553 		if (dd->channel_mic_map[i].ds_pos)
554 			cfgr_val |= MCHP_PDMC_CFGR_PDMSEL(i);
555 		if (dd->channel_mic_map[i].clk_edge)
556 			cfgr_val |= MCHP_PDMC_CFGR_BSSEL(i);
557 	}
558 
559 	/*
560 	 * from these point forward, we consider the controller busy, so the
561 	 * audio filter and SINC order can't be changed
562 	 */
563 	atomic_set(&dd->busy_stream, 1);
564 	for (osr_start = dd->audio_filter_en ? 64 : 8;
565 	     osr_start <= 256 && best_diff_rate; osr_start *= 2) {
566 		long round_rate;
567 		unsigned long diff_rate;
568 
569 		round_rate = clk_round_rate(dd->gclk,
570 					    (unsigned long)fs * 16 * osr_start);
571 		if (round_rate < 0)
572 			continue;
573 		diff_rate = abs((fs * 16 * osr_start) - round_rate);
574 		if (diff_rate < best_diff_rate) {
575 			best_diff_rate = diff_rate;
576 			osr = osr_start;
577 			gclk_rate = fs * 16 * osr;
578 		}
579 	}
580 	if (!gclk_rate) {
581 		dev_err(comp->dev, "invalid sampling rate: %u\n", fs);
582 		return -EINVAL;
583 	}
584 
585 	/* CLK is enabled by runtime PM. */
586 	clk_disable_unprepare(dd->gclk);
587 
588 	/* set the rate */
589 	ret = clk_set_rate(dd->gclk, gclk_rate);
590 	clk_prepare_enable(dd->gclk);
591 	if (ret) {
592 		dev_err(comp->dev, "unable to set rate %lu to GCLK: %d\n",
593 			gclk_rate, ret);
594 		return ret;
595 	}
596 
597 	mr_val |= mchp_pdmc_mr_set_osr(dd->audio_filter_en, osr);
598 
599 	mr_val |= FIELD_PREP(MCHP_PDMC_MR_SINCORDER_MASK, dd->sinc_order);
600 
601 	maxburst = mchp_pdmc_period_to_maxburst(period_bytes, sample_bytes);
602 	dd->addr.maxburst = maxburst;
603 	mr_val |= FIELD_PREP(MCHP_PDMC_MR_CHUNK_MASK, dd->addr.maxburst);
604 	dev_dbg(comp->dev, "maxburst set to %d\n", dd->addr.maxburst);
605 
606 	snd_soc_component_update_bits(comp, MCHP_PDMC_MR,
607 				      MCHP_PDMC_MR_OSR_MASK |
608 				      MCHP_PDMC_MR_SINCORDER_MASK |
609 				      MCHP_PDMC_MR_SINC_OSR_MASK |
610 				      MCHP_PDMC_MR_CHUNK_MASK, mr_val);
611 
612 	snd_soc_component_write(comp, MCHP_PDMC_CFGR, cfgr_val);
613 
614 	return 0;
615 }
616 
617 static void mchp_pdmc_noise_filter_workaround(struct mchp_pdmc *dd)
618 {
619 	u32 tmp, steps = 16;
620 
621 	/*
622 	 * PDMC doesn't wait for microphones' startup time thus the acquisition
623 	 * may start before the microphones are ready leading to poc noises at
624 	 * the beginning of capture. To avoid this, we need to wait 50ms (in
625 	 * normal startup procedure) or 150 ms (worst case after resume from sleep
626 	 * states) after microphones are enabled and then clear the FIFOs (by
627 	 * reading the RHR 16 times) and possible interrupts before continuing.
628 	 * Also, for this to work the DMA needs to be started after interrupts
629 	 * are enabled.
630 	 */
631 	usleep_range(dd->startup_delay_us, dd->startup_delay_us + 5);
632 
633 	while (steps--)
634 		regmap_read(dd->regmap, MCHP_PDMC_RHR, &tmp);
635 
636 	/* Clear interrupts. */
637 	regmap_read(dd->regmap, MCHP_PDMC_ISR, &tmp);
638 }
639 
640 static int mchp_pdmc_trigger(struct snd_pcm_substream *substream,
641 			     int cmd, struct snd_soc_dai *dai)
642 {
643 	struct mchp_pdmc *dd = snd_soc_dai_get_drvdata(dai);
644 	struct snd_soc_component *cpu = dai->component;
645 #ifdef DEBUG
646 	u32 val;
647 #endif
648 
649 	switch (cmd) {
650 	case SNDRV_PCM_TRIGGER_RESUME:
651 	case SNDRV_PCM_TRIGGER_START:
652 	case SNDRV_PCM_TRIGGER_PAUSE_RELEASE:
653 		snd_soc_component_update_bits(cpu, MCHP_PDMC_MR,
654 					      MCHP_PDMC_MR_PDMCEN_MASK,
655 					      dd->pdmcen);
656 
657 		mchp_pdmc_noise_filter_workaround(dd);
658 
659 		/* Enable interrupts. */
660 		regmap_write(dd->regmap, MCHP_PDMC_IER, dd->suspend_irq |
661 			     MCHP_PDMC_IR_RXOVR | MCHP_PDMC_IR_RXUDR);
662 		dd->suspend_irq = 0;
663 		break;
664 	case SNDRV_PCM_TRIGGER_SUSPEND:
665 		regmap_read(dd->regmap, MCHP_PDMC_IMR, &dd->suspend_irq);
666 		fallthrough;
667 	case SNDRV_PCM_TRIGGER_STOP:
668 		/* Disable overrun and underrun error interrupts */
669 		regmap_write(dd->regmap, MCHP_PDMC_IDR, dd->suspend_irq |
670 			     MCHP_PDMC_IR_RXOVR | MCHP_PDMC_IR_RXUDR);
671 		fallthrough;
672 	case SNDRV_PCM_TRIGGER_PAUSE_PUSH:
673 		snd_soc_component_update_bits(cpu, MCHP_PDMC_MR,
674 					      MCHP_PDMC_MR_PDMCEN_MASK, 0);
675 		break;
676 	default:
677 		return -EINVAL;
678 	}
679 
680 #ifdef DEBUG
681 	regmap_read(dd->regmap, MCHP_PDMC_MR, &val);
682 	dev_dbg(dd->dev, "MR (0x%02x): 0x%08x\n", MCHP_PDMC_MR, val);
683 	regmap_read(dd->regmap, MCHP_PDMC_CFGR, &val);
684 	dev_dbg(dd->dev, "CFGR (0x%02x): 0x%08x\n", MCHP_PDMC_CFGR, val);
685 	regmap_read(dd->regmap, MCHP_PDMC_IMR, &val);
686 	dev_dbg(dd->dev, "IMR (0x%02x): 0x%08x\n", MCHP_PDMC_IMR, val);
687 #endif
688 
689 	return 0;
690 }
691 
692 static int mchp_pdmc_add_chmap_ctls(struct snd_pcm *pcm, struct mchp_pdmc *dd)
693 {
694 	struct mchp_pdmc_chmap *info;
695 	struct snd_kcontrol_new knew = {
696 		.iface = SNDRV_CTL_ELEM_IFACE_PCM,
697 		.access = SNDRV_CTL_ELEM_ACCESS_READWRITE |
698 			SNDRV_CTL_ELEM_ACCESS_TLV_READ |
699 			SNDRV_CTL_ELEM_ACCESS_TLV_CALLBACK,
700 		.info = mchp_pdmc_chmap_ctl_info,
701 		.get = mchp_pdmc_chmap_ctl_get,
702 		.put = mchp_pdmc_chmap_ctl_put,
703 		.tlv.c = mchp_pdmc_chmap_ctl_tlv,
704 	};
705 	int err;
706 
707 	if (WARN_ON(pcm->streams[SNDRV_PCM_STREAM_CAPTURE].chmap_kctl))
708 		return -EBUSY;
709 	info = kzalloc(sizeof(*info), GFP_KERNEL);
710 	if (!info)
711 		return -ENOMEM;
712 	info->pcm = pcm;
713 	info->dd = dd;
714 	info->chmap = mchp_pdmc_std_chmaps;
715 	knew.name = "Capture Channel Map";
716 	knew.device = pcm->device;
717 	knew.count = pcm->streams[SNDRV_PCM_STREAM_CAPTURE].substream_count;
718 	info->kctl = snd_ctl_new1(&knew, info);
719 	if (!info->kctl) {
720 		kfree(info);
721 		return -ENOMEM;
722 	}
723 	info->kctl->private_free = mchp_pdmc_chmap_ctl_private_free;
724 	err = snd_ctl_add(pcm->card, info->kctl);
725 	if (err < 0)
726 		return err;
727 	pcm->streams[SNDRV_PCM_STREAM_CAPTURE].chmap_kctl = info->kctl;
728 	return 0;
729 }
730 
731 static int mchp_pdmc_pcm_new(struct snd_soc_pcm_runtime *rtd,
732 			     struct snd_soc_dai *dai)
733 {
734 	struct mchp_pdmc *dd = snd_soc_dai_get_drvdata(dai);
735 	int ret;
736 
737 	ret = mchp_pdmc_add_chmap_ctls(rtd->pcm, dd);
738 	if (ret < 0)
739 		dev_err(dd->dev, "failed to add channel map controls: %d\n", ret);
740 
741 	return ret;
742 }
743 
744 static const struct snd_soc_dai_ops mchp_pdmc_dai_ops = {
745 	.probe		= mchp_pdmc_dai_probe,
746 	.set_fmt	= mchp_pdmc_set_fmt,
747 	.startup	= mchp_pdmc_startup,
748 	.hw_params	= mchp_pdmc_hw_params,
749 	.trigger	= mchp_pdmc_trigger,
750 	.pcm_new	= &mchp_pdmc_pcm_new,
751 };
752 
753 static struct snd_soc_dai_driver mchp_pdmc_dai = {
754 	.name	= "mchp-pdmc",
755 	.capture = {
756 		.stream_name	= "Capture",
757 		.channels_min	= 1,
758 		.channels_max	= 4,
759 		.rate_min	= 8000,
760 		.rate_max	= 192000,
761 		.rates		= SNDRV_PCM_RATE_KNOT,
762 		.formats	= SNDRV_PCM_FMTBIT_S24_LE,
763 	},
764 	.ops = &mchp_pdmc_dai_ops,
765 };
766 
767 /* PDMC interrupt handler */
768 static irqreturn_t mchp_pdmc_interrupt(int irq, void *dev_id)
769 {
770 	struct mchp_pdmc *dd = dev_id;
771 	u32 isr, msr, pending;
772 	irqreturn_t ret = IRQ_NONE;
773 
774 	regmap_read(dd->regmap, MCHP_PDMC_ISR, &isr);
775 	regmap_read(dd->regmap, MCHP_PDMC_IMR, &msr);
776 
777 	pending = isr & msr;
778 	dev_dbg(dd->dev, "ISR (0x%02x): 0x%08x, IMR (0x%02x): 0x%08x, pending: 0x%08x\n",
779 		MCHP_PDMC_ISR, isr, MCHP_PDMC_IMR, msr, pending);
780 	if (!pending)
781 		return IRQ_NONE;
782 
783 	if (pending & MCHP_PDMC_IR_RXUDR) {
784 		dev_warn(dd->dev, "underrun detected\n");
785 		regmap_write(dd->regmap, MCHP_PDMC_IDR, MCHP_PDMC_IR_RXUDR);
786 		ret = IRQ_HANDLED;
787 	}
788 	if (pending & MCHP_PDMC_IR_RXOVR) {
789 		dev_warn(dd->dev, "overrun detected\n");
790 		regmap_write(dd->regmap, MCHP_PDMC_IDR, MCHP_PDMC_IR_RXOVR);
791 		ret = IRQ_HANDLED;
792 	}
793 
794 	return ret;
795 }
796 
797 /* regmap configuration */
798 static bool mchp_pdmc_readable_reg(struct device *dev, unsigned int reg)
799 {
800 	switch (reg) {
801 	case MCHP_PDMC_MR:
802 	case MCHP_PDMC_CFGR:
803 	case MCHP_PDMC_IMR:
804 	case MCHP_PDMC_ISR:
805 	case MCHP_PDMC_RHR:
806 	case MCHP_PDMC_VER:
807 		return true;
808 	default:
809 		return false;
810 	}
811 }
812 
813 static bool mchp_pdmc_writeable_reg(struct device *dev, unsigned int reg)
814 {
815 	switch (reg) {
816 	case MCHP_PDMC_CR:
817 	case MCHP_PDMC_MR:
818 	case MCHP_PDMC_CFGR:
819 	case MCHP_PDMC_IER:
820 	case MCHP_PDMC_IDR:
821 		return true;
822 	default:
823 		return false;
824 	}
825 }
826 
827 static bool mchp_pdmc_volatile_reg(struct device *dev, unsigned int reg)
828 {
829 	switch (reg) {
830 	case MCHP_PDMC_ISR:
831 	case MCHP_PDMC_RHR:
832 		return true;
833 	default:
834 		return false;
835 	}
836 }
837 
838 static bool mchp_pdmc_precious_reg(struct device *dev, unsigned int reg)
839 {
840 	switch (reg) {
841 	case MCHP_PDMC_RHR:
842 	case MCHP_PDMC_ISR:
843 		return true;
844 	default:
845 		return false;
846 	}
847 }
848 
849 static const struct regmap_config mchp_pdmc_regmap_config = {
850 	.reg_bits	= 32,
851 	.reg_stride	= 4,
852 	.val_bits	= 32,
853 	.max_register	= MCHP_PDMC_VER,
854 	.readable_reg	= mchp_pdmc_readable_reg,
855 	.writeable_reg	= mchp_pdmc_writeable_reg,
856 	.precious_reg	= mchp_pdmc_precious_reg,
857 	.volatile_reg	= mchp_pdmc_volatile_reg,
858 	.cache_type	= REGCACHE_FLAT,
859 };
860 
861 static int mchp_pdmc_dt_init(struct mchp_pdmc *dd)
862 {
863 	struct device_node *np = dd->dev->of_node;
864 	bool mic_ch[MCHP_PDMC_DS_NO][MCHP_PDMC_EDGE_NO] = {0};
865 	int i;
866 	int ret;
867 
868 	if (!np) {
869 		dev_err(dd->dev, "device node not found\n");
870 		return -EINVAL;
871 	}
872 
873 	dd->mic_no = of_property_count_u32_elems(np, "microchip,mic-pos");
874 	if (dd->mic_no < 0) {
875 		dev_err(dd->dev, "failed to get microchip,mic-pos: %d",
876 			dd->mic_no);
877 		return dd->mic_no;
878 	}
879 	if (!dd->mic_no || dd->mic_no % 2 ||
880 	    dd->mic_no / 2 > MCHP_PDMC_MAX_CHANNELS) {
881 		dev_err(dd->dev, "invalid array length for microchip,mic-pos: %d",
882 			dd->mic_no);
883 		return -EINVAL;
884 	}
885 
886 	dd->mic_no /= 2;
887 
888 	dev_info(dd->dev, "%d PDM microphones declared\n", dd->mic_no);
889 
890 	/*
891 	 * by default, we consider the order of microphones in
892 	 * microchip,mic-pos to be the same with the channel mapping;
893 	 * 1st microphone channel 0, 2nd microphone channel 1, etc.
894 	 */
895 	for (i = 0; i < dd->mic_no; i++) {
896 		int ds;
897 		int edge;
898 
899 		ret = of_property_read_u32_index(np, "microchip,mic-pos", i * 2,
900 						 &ds);
901 		if (ret) {
902 			dev_err(dd->dev,
903 				"failed to get value no %d value from microchip,mic-pos: %d",
904 				i * 2, ret);
905 			return ret;
906 		}
907 		if (ds >= MCHP_PDMC_DS_NO) {
908 			dev_err(dd->dev,
909 				"invalid DS index in microchip,mic-pos array: %d",
910 				ds);
911 			return -EINVAL;
912 		}
913 
914 		ret = of_property_read_u32_index(np, "microchip,mic-pos", i * 2 + 1,
915 						 &edge);
916 		if (ret) {
917 			dev_err(dd->dev,
918 				"failed to get value no %d value from microchip,mic-pos: %d",
919 				i * 2 + 1, ret);
920 			return ret;
921 		}
922 
923 		if (edge != MCHP_PDMC_CLK_POSITIVE &&
924 		    edge != MCHP_PDMC_CLK_NEGATIVE) {
925 			dev_err(dd->dev,
926 				"invalid edge in microchip,mic-pos array: %d", edge);
927 			return -EINVAL;
928 		}
929 		if (mic_ch[ds][edge]) {
930 			dev_err(dd->dev,
931 				"duplicated mic (DS %d, edge %d) in microchip,mic-pos array",
932 				ds, edge);
933 			return -EINVAL;
934 		}
935 		mic_ch[ds][edge] = true;
936 		dd->channel_mic_map[i].ds_pos = ds;
937 		dd->channel_mic_map[i].clk_edge = edge;
938 	}
939 
940 	dd->startup_delay_us = 150000;
941 	of_property_read_u32(np, "microchip,startup-delay-us", &dd->startup_delay_us);
942 
943 	return 0;
944 }
945 
946 /* used to clean the channel index found on RHR's MSB */
947 static int mchp_pdmc_process(struct snd_pcm_substream *substream,
948 			     int channel, unsigned long hwoff,
949 			     unsigned long bytes)
950 {
951 	struct snd_pcm_runtime *runtime = substream->runtime;
952 	u8 *dma_ptr = runtime->dma_area + hwoff +
953 		      channel * (runtime->dma_bytes / runtime->channels);
954 	u8 *dma_ptr_end = dma_ptr + bytes;
955 	unsigned int sample_size = samples_to_bytes(runtime, 1);
956 
957 	for (; dma_ptr < dma_ptr_end; dma_ptr += sample_size)
958 		*dma_ptr = 0;
959 
960 	return 0;
961 }
962 
963 static struct snd_dmaengine_pcm_config mchp_pdmc_config = {
964 	.process = mchp_pdmc_process,
965 	.prepare_slave_config = snd_dmaengine_pcm_prepare_slave_config,
966 };
967 
968 static int mchp_pdmc_runtime_suspend(struct device *dev)
969 {
970 	struct mchp_pdmc *dd = dev_get_drvdata(dev);
971 
972 	regcache_cache_only(dd->regmap, true);
973 
974 	clk_disable_unprepare(dd->gclk);
975 	clk_disable_unprepare(dd->pclk);
976 
977 	return 0;
978 }
979 
980 static int mchp_pdmc_runtime_resume(struct device *dev)
981 {
982 	struct mchp_pdmc *dd = dev_get_drvdata(dev);
983 	int ret;
984 
985 	ret = clk_prepare_enable(dd->pclk);
986 	if (ret) {
987 		dev_err(dd->dev,
988 			"failed to enable the peripheral clock: %d\n", ret);
989 		return ret;
990 	}
991 	ret = clk_prepare_enable(dd->gclk);
992 	if (ret) {
993 		dev_err(dd->dev,
994 			"failed to enable generic clock: %d\n", ret);
995 		goto disable_pclk;
996 	}
997 
998 	regcache_cache_only(dd->regmap, false);
999 	regcache_mark_dirty(dd->regmap);
1000 	ret = regcache_sync(dd->regmap);
1001 	if (ret) {
1002 		regcache_cache_only(dd->regmap, true);
1003 		clk_disable_unprepare(dd->gclk);
1004 disable_pclk:
1005 		clk_disable_unprepare(dd->pclk);
1006 	}
1007 
1008 	return ret;
1009 }
1010 
1011 static int mchp_pdmc_probe(struct platform_device *pdev)
1012 {
1013 	struct device *dev = &pdev->dev;
1014 	struct mchp_pdmc *dd;
1015 	struct resource *res;
1016 	void __iomem *io_base;
1017 	u32 version;
1018 	int irq;
1019 	int ret;
1020 
1021 	dd = devm_kzalloc(dev, sizeof(*dd), GFP_KERNEL);
1022 	if (!dd)
1023 		return -ENOMEM;
1024 
1025 	dd->dev = &pdev->dev;
1026 	ret = mchp_pdmc_dt_init(dd);
1027 	if (ret < 0)
1028 		return ret;
1029 
1030 	irq = platform_get_irq(pdev, 0);
1031 	if (irq < 0)
1032 		return irq;
1033 
1034 	dd->pclk = devm_clk_get(dev, "pclk");
1035 	if (IS_ERR(dd->pclk)) {
1036 		ret = PTR_ERR(dd->pclk);
1037 		dev_err(dev, "failed to get peripheral clock: %d\n", ret);
1038 		return ret;
1039 	}
1040 
1041 	dd->gclk = devm_clk_get(dev, "gclk");
1042 	if (IS_ERR(dd->gclk)) {
1043 		ret = PTR_ERR(dd->gclk);
1044 		dev_err(dev, "failed to get GCK: %d\n", ret);
1045 		return ret;
1046 	}
1047 
1048 	io_base = devm_platform_get_and_ioremap_resource(pdev, 0, &res);
1049 	if (IS_ERR(io_base)) {
1050 		ret = PTR_ERR(io_base);
1051 		dev_err(dev, "failed to remap register memory: %d\n", ret);
1052 		return ret;
1053 	}
1054 
1055 	dd->regmap = devm_regmap_init_mmio(dev, io_base,
1056 					   &mchp_pdmc_regmap_config);
1057 	if (IS_ERR(dd->regmap)) {
1058 		ret = PTR_ERR(dd->regmap);
1059 		dev_err(dev, "failed to init register map: %d\n", ret);
1060 		return ret;
1061 	}
1062 
1063 	ret = devm_request_irq(dev, irq, mchp_pdmc_interrupt, 0,
1064 			       dev_name(&pdev->dev), dd);
1065 	if (ret < 0) {
1066 		dev_err(dev, "can't register ISR for IRQ %u (ret=%i)\n",
1067 			irq, ret);
1068 		return ret;
1069 	}
1070 
1071 	/* by default audio filter is enabled and the SINC Filter order
1072 	 * will be set to the recommended value, 3
1073 	 */
1074 	dd->audio_filter_en = true;
1075 	dd->sinc_order = 3;
1076 
1077 	dd->addr.addr = (dma_addr_t)res->start + MCHP_PDMC_RHR;
1078 	platform_set_drvdata(pdev, dd);
1079 
1080 	pm_runtime_enable(dd->dev);
1081 	if (!pm_runtime_enabled(dd->dev)) {
1082 		ret = mchp_pdmc_runtime_resume(dd->dev);
1083 		if (ret)
1084 			return ret;
1085 	}
1086 
1087 	/* register platform */
1088 	ret = devm_snd_dmaengine_pcm_register(dev, &mchp_pdmc_config, 0);
1089 	if (ret) {
1090 		dev_err(dev, "could not register platform: %d\n", ret);
1091 		goto pm_runtime_suspend;
1092 	}
1093 
1094 	ret = devm_snd_soc_register_component(dev, &mchp_pdmc_dai_component,
1095 					      &mchp_pdmc_dai, 1);
1096 	if (ret) {
1097 		dev_err(dev, "could not register CPU DAI: %d\n", ret);
1098 		goto pm_runtime_suspend;
1099 	}
1100 
1101 	/* print IP version */
1102 	regmap_read(dd->regmap, MCHP_PDMC_VER, &version);
1103 	dev_info(dd->dev, "hw version: %#lx\n",
1104 		 version & MCHP_PDMC_VER_VERSION);
1105 
1106 	return 0;
1107 
1108 pm_runtime_suspend:
1109 	if (!pm_runtime_status_suspended(dd->dev))
1110 		mchp_pdmc_runtime_suspend(dd->dev);
1111 	pm_runtime_disable(dd->dev);
1112 
1113 	return ret;
1114 }
1115 
1116 static void mchp_pdmc_remove(struct platform_device *pdev)
1117 {
1118 	struct mchp_pdmc *dd = platform_get_drvdata(pdev);
1119 
1120 	atomic_set(&dd->busy_stream, 0);
1121 
1122 	if (!pm_runtime_status_suspended(dd->dev))
1123 		mchp_pdmc_runtime_suspend(dd->dev);
1124 
1125 	pm_runtime_disable(dd->dev);
1126 }
1127 
1128 static const struct of_device_id mchp_pdmc_of_match[] = {
1129 	{
1130 		.compatible = "microchip,sama7g5-pdmc",
1131 	}, {
1132 		/* sentinel */
1133 	}
1134 };
1135 MODULE_DEVICE_TABLE(of, mchp_pdmc_of_match);
1136 
1137 static const struct dev_pm_ops mchp_pdmc_pm_ops = {
1138 	SYSTEM_SLEEP_PM_OPS(pm_runtime_force_suspend, pm_runtime_force_resume)
1139 	RUNTIME_PM_OPS(mchp_pdmc_runtime_suspend, mchp_pdmc_runtime_resume,
1140 		       NULL)
1141 };
1142 
1143 static struct platform_driver mchp_pdmc_driver = {
1144 	.driver	= {
1145 		.name		= "mchp-pdmc",
1146 		.of_match_table	= of_match_ptr(mchp_pdmc_of_match),
1147 		.pm		= pm_ptr(&mchp_pdmc_pm_ops),
1148 	},
1149 	.probe	= mchp_pdmc_probe,
1150 	.remove = mchp_pdmc_remove,
1151 };
1152 module_platform_driver(mchp_pdmc_driver);
1153 
1154 MODULE_DESCRIPTION("Microchip PDMC driver under ALSA SoC architecture");
1155 MODULE_AUTHOR("Codrin Ciubotariu <codrin.ciubotariu@microchip.com>");
1156 MODULE_LICENSE("GPL v2");
1157