xref: /openbmc/linux/sound/soc/atmel/mchp-pdmc.c (revision 69d0fd34)
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 struct mic_map {
94 	int ds_pos;
95 	int clk_edge;
96 };
97 
98 struct mchp_pdmc_chmap {
99 	struct snd_pcm_chmap_elem *chmap;
100 	struct mchp_pdmc *dd;
101 	struct snd_pcm *pcm;
102 	struct snd_kcontrol *kctl;
103 };
104 
105 struct mchp_pdmc {
106 	struct mic_map channel_mic_map[MCHP_PDMC_MAX_CHANNELS];
107 	struct device *dev;
108 	struct snd_dmaengine_dai_dma_data addr;
109 	struct regmap *regmap;
110 	struct clk *pclk;
111 	struct clk *gclk;
112 	u32 pdmcen;
113 	u32 suspend_irq;
114 	u32 startup_delay_us;
115 	int mic_no;
116 	int sinc_order;
117 	bool audio_filter_en;
118 };
119 
120 static const char *const mchp_pdmc_sinc_filter_order_text[] = {
121 	"1", "2", "3", "4", "5"
122 };
123 
124 static const unsigned int mchp_pdmc_sinc_filter_order_values[] = {
125 	1, 2, 3, 4, 5,
126 };
127 
128 static const struct soc_enum mchp_pdmc_sinc_filter_order_enum = {
129 	.items = ARRAY_SIZE(mchp_pdmc_sinc_filter_order_text),
130 	.texts = mchp_pdmc_sinc_filter_order_text,
131 	.values = mchp_pdmc_sinc_filter_order_values,
132 };
133 
134 static int mchp_pdmc_sinc_order_get(struct snd_kcontrol *kcontrol,
135 				    struct snd_ctl_elem_value *uvalue)
136 {
137 	struct snd_soc_component *component = snd_kcontrol_chip(kcontrol);
138 	struct mchp_pdmc *dd = snd_soc_component_get_drvdata(component);
139 	struct soc_enum *e = (struct soc_enum *)kcontrol->private_value;
140 	unsigned int item;
141 
142 	item = snd_soc_enum_val_to_item(e, dd->sinc_order);
143 	uvalue->value.enumerated.item[0] = item;
144 
145 	return 0;
146 }
147 
148 static int mchp_pdmc_sinc_order_put(struct snd_kcontrol *kcontrol,
149 				    struct snd_ctl_elem_value *uvalue)
150 {
151 	struct snd_soc_component *component = snd_kcontrol_chip(kcontrol);
152 	struct mchp_pdmc *dd = snd_soc_component_get_drvdata(component);
153 	struct soc_enum *e = (struct soc_enum *)kcontrol->private_value;
154 	unsigned int *item = uvalue->value.enumerated.item;
155 	unsigned int val;
156 
157 	if (item[0] >= e->items)
158 		return -EINVAL;
159 
160 	val = snd_soc_enum_item_to_val(e, item[0]) << e->shift_l;
161 	if (val == dd->sinc_order)
162 		return 0;
163 
164 	dd->sinc_order = val;
165 
166 	return 1;
167 }
168 
169 static int mchp_pdmc_af_get(struct snd_kcontrol *kcontrol,
170 			    struct snd_ctl_elem_value *uvalue)
171 {
172 	struct snd_soc_component *component = snd_kcontrol_chip(kcontrol);
173 	struct mchp_pdmc *dd = snd_soc_component_get_drvdata(component);
174 
175 	uvalue->value.integer.value[0] = !!dd->audio_filter_en;
176 
177 	return 0;
178 }
179 
180 static int mchp_pdmc_af_put(struct snd_kcontrol *kcontrol,
181 			    struct snd_ctl_elem_value *uvalue)
182 {
183 	struct snd_soc_component *component = snd_kcontrol_chip(kcontrol);
184 	struct mchp_pdmc *dd = snd_soc_component_get_drvdata(component);
185 	bool af = uvalue->value.integer.value[0] ? true : false;
186 
187 	if (dd->audio_filter_en == af)
188 		return 0;
189 
190 	dd->audio_filter_en = af;
191 
192 	return 1;
193 }
194 
195 static int mchp_pdmc_chmap_ctl_info(struct snd_kcontrol *kcontrol, struct snd_ctl_elem_info *uinfo)
196 {
197 	struct mchp_pdmc_chmap *info = snd_kcontrol_chip(kcontrol);
198 
199 	uinfo->type = SNDRV_CTL_ELEM_TYPE_INTEGER;
200 	uinfo->count = info->dd->mic_no;
201 	uinfo->value.integer.min = 0;
202 	uinfo->value.integer.max = SNDRV_CHMAP_RR; /* maxmimum 4 channels */
203 	return 0;
204 }
205 
206 static inline struct snd_pcm_substream *
207 mchp_pdmc_chmap_substream(struct mchp_pdmc_chmap *info, unsigned int idx)
208 {
209 	struct snd_pcm_substream *s;
210 
211 	for (s = info->pcm->streams[SNDRV_PCM_STREAM_CAPTURE].substream; s; s = s->next)
212 		if (s->number == idx)
213 			return s;
214 	return NULL;
215 }
216 
217 static struct snd_pcm_chmap_elem *mchp_pdmc_chmap_get(struct snd_pcm_substream *substream,
218 						      struct mchp_pdmc_chmap *ch_info)
219 {
220 	struct snd_pcm_chmap_elem *map;
221 
222 	for (map = ch_info->chmap; map->channels; map++) {
223 		if (map->channels == substream->runtime->channels)
224 			return map;
225 	}
226 	return NULL;
227 }
228 
229 static int mchp_pdmc_chmap_ctl_get(struct snd_kcontrol *kcontrol,
230 				   struct snd_ctl_elem_value *ucontrol)
231 {
232 	struct mchp_pdmc_chmap *info = snd_kcontrol_chip(kcontrol);
233 	struct mchp_pdmc *dd = info->dd;
234 	unsigned int idx = snd_ctl_get_ioffidx(kcontrol, &ucontrol->id);
235 	struct snd_pcm_substream *substream;
236 	const struct snd_pcm_chmap_elem *map;
237 	int i;
238 	u32 cfgr_val = 0;
239 
240 	if (!info->chmap)
241 		return -EINVAL;
242 	substream = mchp_pdmc_chmap_substream(info, idx);
243 	if (!substream)
244 		return -ENODEV;
245 	memset(ucontrol->value.integer.value, 0, sizeof(long) * info->dd->mic_no);
246 	if (!substream->runtime)
247 		return 0; /* no channels set */
248 
249 	map = mchp_pdmc_chmap_get(substream, info);
250 	if (!map)
251 		return -EINVAL;
252 
253 	for (i = 0; i < map->channels; i++) {
254 		int map_idx = map->channels == 1 ? map->map[i] - SNDRV_CHMAP_MONO :
255 						   map->map[i] - SNDRV_CHMAP_FL;
256 
257 		/* make sure the reported channel map is the real one, so write the map */
258 		if (dd->channel_mic_map[map_idx].ds_pos)
259 			cfgr_val |= MCHP_PDMC_CFGR_PDMSEL(i);
260 		if (dd->channel_mic_map[map_idx].clk_edge)
261 			cfgr_val |= MCHP_PDMC_CFGR_BSSEL(i);
262 
263 		ucontrol->value.integer.value[i] = map->map[i];
264 	}
265 
266 	regmap_write(dd->regmap, MCHP_PDMC_CFGR, cfgr_val);
267 
268 	return 0;
269 }
270 
271 static int mchp_pdmc_chmap_ctl_put(struct snd_kcontrol *kcontrol,
272 				   struct snd_ctl_elem_value *ucontrol)
273 {
274 	struct mchp_pdmc_chmap *info = snd_kcontrol_chip(kcontrol);
275 	struct mchp_pdmc *dd = info->dd;
276 	unsigned int idx = snd_ctl_get_ioffidx(kcontrol, &ucontrol->id);
277 	struct snd_pcm_substream *substream;
278 	struct snd_pcm_chmap_elem *map;
279 	u32 cfgr_val = 0;
280 	int i;
281 
282 	if (!info->chmap)
283 		return -EINVAL;
284 	substream = mchp_pdmc_chmap_substream(info, idx);
285 	if (!substream)
286 		return -ENODEV;
287 
288 	map = mchp_pdmc_chmap_get(substream, info);
289 	if (!map)
290 		return -EINVAL;
291 
292 	for (i = 0; i < map->channels; i++) {
293 		int map_idx;
294 
295 		map->map[i] = ucontrol->value.integer.value[i];
296 		map_idx = map->channels == 1 ? map->map[i] - SNDRV_CHMAP_MONO :
297 					       map->map[i] - SNDRV_CHMAP_FL;
298 
299 		/* configure IP for the desired channel map */
300 		if (dd->channel_mic_map[map_idx].ds_pos)
301 			cfgr_val |= MCHP_PDMC_CFGR_PDMSEL(i);
302 		if (dd->channel_mic_map[map_idx].clk_edge)
303 			cfgr_val |= MCHP_PDMC_CFGR_BSSEL(i);
304 	}
305 
306 	regmap_write(dd->regmap, MCHP_PDMC_CFGR, cfgr_val);
307 
308 	return 0;
309 }
310 
311 static void mchp_pdmc_chmap_ctl_private_free(struct snd_kcontrol *kcontrol)
312 {
313 	struct mchp_pdmc_chmap *info = snd_kcontrol_chip(kcontrol);
314 
315 	info->pcm->streams[SNDRV_PCM_STREAM_CAPTURE].chmap_kctl = NULL;
316 	kfree(info);
317 }
318 
319 static int mchp_pdmc_chmap_ctl_tlv(struct snd_kcontrol *kcontrol, int op_flag,
320 				   unsigned int size, unsigned int __user *tlv)
321 {
322 	struct mchp_pdmc_chmap *info = snd_kcontrol_chip(kcontrol);
323 	const struct snd_pcm_chmap_elem *map;
324 	unsigned int __user *dst;
325 	int c, count = 0;
326 
327 	if (!info->chmap)
328 		return -EINVAL;
329 	if (size < 8)
330 		return -ENOMEM;
331 	if (put_user(SNDRV_CTL_TLVT_CONTAINER, tlv))
332 		return -EFAULT;
333 	size -= 8;
334 	dst = tlv + 2;
335 	for (map = info->chmap; map->channels; map++) {
336 		int chs_bytes = map->channels * 4;
337 
338 		if (size < 8)
339 			return -ENOMEM;
340 		if (put_user(SNDRV_CTL_TLVT_CHMAP_VAR, dst) ||
341 		    put_user(chs_bytes, dst + 1))
342 			return -EFAULT;
343 		dst += 2;
344 		size -= 8;
345 		count += 8;
346 		if (size < chs_bytes)
347 			return -ENOMEM;
348 		size -= chs_bytes;
349 		count += chs_bytes;
350 		for (c = 0; c < map->channels; c++) {
351 			if (put_user(map->map[c], dst))
352 				return -EFAULT;
353 			dst++;
354 		}
355 	}
356 	if (put_user(count, tlv + 1))
357 		return -EFAULT;
358 	return 0;
359 }
360 
361 static const struct snd_kcontrol_new mchp_pdmc_snd_controls[] = {
362 	SOC_SINGLE_BOOL_EXT("Audio Filter", 0, &mchp_pdmc_af_get, &mchp_pdmc_af_put),
363 	{
364 		.iface = SNDRV_CTL_ELEM_IFACE_MIXER,
365 		.name = "SINC Filter Order",
366 		.info = snd_soc_info_enum_double,
367 		.get = mchp_pdmc_sinc_order_get,
368 		.put = mchp_pdmc_sinc_order_put,
369 		.private_value = (unsigned long)&mchp_pdmc_sinc_filter_order_enum,
370 	},
371 };
372 
373 static int mchp_pdmc_close(struct snd_soc_component *component,
374 			   struct snd_pcm_substream *substream)
375 {
376 	return snd_soc_add_component_controls(component, mchp_pdmc_snd_controls,
377 					      ARRAY_SIZE(mchp_pdmc_snd_controls));
378 }
379 
380 static int mchp_pdmc_open(struct snd_soc_component *component,
381 			  struct snd_pcm_substream *substream)
382 {
383 	int i;
384 
385 	/* remove controls that can't be changed at runtime */
386 	for (i = 0; i < ARRAY_SIZE(mchp_pdmc_snd_controls); i++) {
387 		const struct snd_kcontrol_new *control = &mchp_pdmc_snd_controls[i];
388 		struct snd_ctl_elem_id id;
389 		int err;
390 
391 		if (component->name_prefix)
392 			snprintf(id.name, sizeof(id.name), "%s %s", component->name_prefix,
393 				 control->name);
394 		else
395 			strscpy(id.name, control->name, sizeof(id.name));
396 
397 		id.numid = 0;
398 		id.iface = control->iface;
399 		id.device = control->device;
400 		id.subdevice = control->subdevice;
401 		id.index = control->index;
402 		err = snd_ctl_remove_id(component->card->snd_card, &id);
403 		if (err < 0)
404 			dev_err(component->dev, "%d: Failed to remove %s\n", err,
405 				control->name);
406 	}
407 
408 	return 0;
409 }
410 
411 static const struct snd_soc_component_driver mchp_pdmc_dai_component = {
412 	.name = "mchp-pdmc",
413 	.controls = mchp_pdmc_snd_controls,
414 	.num_controls = ARRAY_SIZE(mchp_pdmc_snd_controls),
415 	.open = &mchp_pdmc_open,
416 	.close = &mchp_pdmc_close,
417 	.legacy_dai_naming = 1,
418 	.trigger_start = SND_SOC_TRIGGER_ORDER_LDC,
419 };
420 
421 static const unsigned int mchp_pdmc_1mic[] = {1};
422 static const unsigned int mchp_pdmc_2mic[] = {1, 2};
423 static const unsigned int mchp_pdmc_3mic[] = {1, 2, 3};
424 static const unsigned int mchp_pdmc_4mic[] = {1, 2, 3, 4};
425 
426 static const struct snd_pcm_hw_constraint_list mchp_pdmc_chan_constr[] = {
427 	{
428 		.list = mchp_pdmc_1mic,
429 		.count = ARRAY_SIZE(mchp_pdmc_1mic),
430 	},
431 	{
432 		.list = mchp_pdmc_2mic,
433 		.count = ARRAY_SIZE(mchp_pdmc_2mic),
434 	},
435 	{
436 		.list = mchp_pdmc_3mic,
437 		.count = ARRAY_SIZE(mchp_pdmc_3mic),
438 	},
439 	{
440 		.list = mchp_pdmc_4mic,
441 		.count = ARRAY_SIZE(mchp_pdmc_4mic),
442 	},
443 };
444 
445 static int mchp_pdmc_startup(struct snd_pcm_substream *substream,
446 			     struct snd_soc_dai *dai)
447 {
448 	struct mchp_pdmc *dd = snd_soc_dai_get_drvdata(dai);
449 
450 	regmap_write(dd->regmap, MCHP_PDMC_CR, MCHP_PDMC_CR_SWRST);
451 
452 	snd_pcm_hw_constraint_list(substream->runtime, 0, SNDRV_PCM_HW_PARAM_CHANNELS,
453 				   &mchp_pdmc_chan_constr[dd->mic_no - 1]);
454 
455 	return 0;
456 }
457 
458 static int mchp_pdmc_dai_probe(struct snd_soc_dai *dai)
459 {
460 	struct mchp_pdmc *dd = snd_soc_dai_get_drvdata(dai);
461 
462 	snd_soc_dai_init_dma_data(dai, NULL, &dd->addr);
463 
464 	return 0;
465 }
466 
467 static int mchp_pdmc_set_fmt(struct snd_soc_dai *dai, unsigned int fmt)
468 {
469 	unsigned int fmt_master = fmt & SND_SOC_DAIFMT_MASTER_MASK;
470 	unsigned int fmt_format = fmt & SND_SOC_DAIFMT_FORMAT_MASK;
471 
472 	/* IP needs to be bitclock master */
473 	if (fmt_master != SND_SOC_DAIFMT_BP_FP &&
474 	    fmt_master != SND_SOC_DAIFMT_BP_FC)
475 		return -EINVAL;
476 
477 	/* IP supports only PDM interface */
478 	if (fmt_format != SND_SOC_DAIFMT_PDM)
479 		return -EINVAL;
480 
481 	return 0;
482 }
483 
484 static u32 mchp_pdmc_mr_set_osr(int audio_filter_en, unsigned int osr)
485 {
486 	if (audio_filter_en) {
487 		switch (osr) {
488 		case 64:
489 			return MCHP_PDMC_MR_OSR64;
490 		case 128:
491 			return MCHP_PDMC_MR_OSR128;
492 		case 256:
493 			return MCHP_PDMC_MR_OSR256;
494 		}
495 	} else {
496 		switch (osr) {
497 		case 8:
498 			return MCHP_PDMC_MR_SINC_OSR_8;
499 		case 16:
500 			return MCHP_PDMC_MR_SINC_OSR_16;
501 		case 32:
502 			return MCHP_PDMC_MR_SINC_OSR_32;
503 		case 64:
504 			return MCHP_PDMC_MR_SINC_OSR_64;
505 		case 128:
506 			return MCHP_PDMC_MR_SINC_OSR_128;
507 		case 256:
508 			return MCHP_PDMC_MR_SINC_OSR_256;
509 		}
510 	}
511 	return 0;
512 }
513 
514 static inline int mchp_pdmc_period_to_maxburst(int period_size)
515 {
516 	if (!(period_size % 8))
517 		return 8;
518 	if (!(period_size % 4))
519 		return 4;
520 	if (!(period_size % 2))
521 		return 2;
522 	return 1;
523 }
524 
525 static struct snd_pcm_chmap_elem mchp_pdmc_std_chmaps[] = {
526 	{ .channels = 1,
527 	  .map = { SNDRV_CHMAP_MONO } },
528 	{ .channels = 2,
529 	  .map = { SNDRV_CHMAP_FL, SNDRV_CHMAP_FR } },
530 	{ .channels = 3,
531 	  .map = { SNDRV_CHMAP_FL, SNDRV_CHMAP_FR,
532 		   SNDRV_CHMAP_RL } },
533 	{ .channels = 4,
534 	  .map = { SNDRV_CHMAP_FL, SNDRV_CHMAP_FR,
535 		   SNDRV_CHMAP_RL, SNDRV_CHMAP_RR } },
536 	{ }
537 };
538 
539 static int mchp_pdmc_hw_params(struct snd_pcm_substream *substream,
540 			       struct snd_pcm_hw_params *params,
541 			       struct snd_soc_dai *dai)
542 {
543 	struct mchp_pdmc *dd = snd_soc_dai_get_drvdata(dai);
544 	struct snd_soc_component *comp = dai->component;
545 	unsigned long gclk_rate = 0;
546 	unsigned long best_diff_rate = ~0UL;
547 	unsigned int channels = params_channels(params);
548 	unsigned int osr = 0, osr_start;
549 	unsigned int fs = params_rate(params);
550 	u32 mr_val = 0;
551 	u32 cfgr_val = 0;
552 	int i;
553 	int ret;
554 
555 	dev_dbg(comp->dev, "%s() rate=%u format=%#x width=%u channels=%u\n",
556 		__func__, params_rate(params), params_format(params),
557 		params_width(params), params_channels(params));
558 
559 	if (channels > dd->mic_no) {
560 		dev_err(comp->dev, "more channels %u than microphones %d\n",
561 			channels, dd->mic_no);
562 		return -EINVAL;
563 	}
564 
565 	dd->pdmcen = 0;
566 	for (i = 0; i < channels; i++) {
567 		dd->pdmcen |= MCHP_PDMC_MR_PDMCEN(i);
568 		if (dd->channel_mic_map[i].ds_pos)
569 			cfgr_val |= MCHP_PDMC_CFGR_PDMSEL(i);
570 		if (dd->channel_mic_map[i].clk_edge)
571 			cfgr_val |= MCHP_PDMC_CFGR_BSSEL(i);
572 	}
573 
574 	for (osr_start = dd->audio_filter_en ? 64 : 8;
575 	     osr_start <= 256 && best_diff_rate; osr_start *= 2) {
576 		long round_rate;
577 		unsigned long diff_rate;
578 
579 		round_rate = clk_round_rate(dd->gclk,
580 					    (unsigned long)fs * 16 * osr_start);
581 		if (round_rate < 0)
582 			continue;
583 		diff_rate = abs((fs * 16 * osr_start) - round_rate);
584 		if (diff_rate < best_diff_rate) {
585 			best_diff_rate = diff_rate;
586 			osr = osr_start;
587 			gclk_rate = fs * 16 * osr;
588 		}
589 	}
590 	if (!gclk_rate) {
591 		dev_err(comp->dev, "invalid sampling rate: %u\n", fs);
592 		return -EINVAL;
593 	}
594 
595 	/* CLK is enabled by runtime PM. */
596 	clk_disable_unprepare(dd->gclk);
597 
598 	/* set the rate */
599 	ret = clk_set_rate(dd->gclk, gclk_rate);
600 	clk_prepare_enable(dd->gclk);
601 	if (ret) {
602 		dev_err(comp->dev, "unable to set rate %lu to GCLK: %d\n",
603 			gclk_rate, ret);
604 		return ret;
605 	}
606 
607 	mr_val |= mchp_pdmc_mr_set_osr(dd->audio_filter_en, osr);
608 
609 	mr_val |= FIELD_PREP(MCHP_PDMC_MR_SINCORDER_MASK, dd->sinc_order);
610 
611 	dd->addr.maxburst = mchp_pdmc_period_to_maxburst(snd_pcm_lib_period_bytes(substream));
612 	mr_val |= FIELD_PREP(MCHP_PDMC_MR_CHUNK_MASK, dd->addr.maxburst);
613 	dev_dbg(comp->dev, "maxburst set to %d\n", dd->addr.maxburst);
614 
615 	snd_soc_component_update_bits(comp, MCHP_PDMC_MR,
616 				      MCHP_PDMC_MR_OSR_MASK |
617 				      MCHP_PDMC_MR_SINCORDER_MASK |
618 				      MCHP_PDMC_MR_SINC_OSR_MASK |
619 				      MCHP_PDMC_MR_CHUNK_MASK, mr_val);
620 
621 	snd_soc_component_write(comp, MCHP_PDMC_CFGR, cfgr_val);
622 
623 	return 0;
624 }
625 
626 static void mchp_pdmc_noise_filter_workaround(struct mchp_pdmc *dd)
627 {
628 	u32 tmp, steps = 16;
629 
630 	/*
631 	 * PDMC doesn't wait for microphones' startup time thus the acquisition
632 	 * may start before the microphones are ready leading to poc noises at
633 	 * the beginning of capture. To avoid this, we need to wait 50ms (in
634 	 * normal startup procedure) or 150 ms (worst case after resume from sleep
635 	 * states) after microphones are enabled and then clear the FIFOs (by
636 	 * reading the RHR 16 times) and possible interrupts before continuing.
637 	 * Also, for this to work the DMA needs to be started after interrupts
638 	 * are enabled.
639 	 */
640 	usleep_range(dd->startup_delay_us, dd->startup_delay_us + 5);
641 
642 	while (steps--)
643 		regmap_read(dd->regmap, MCHP_PDMC_RHR, &tmp);
644 
645 	/* Clear interrupts. */
646 	regmap_read(dd->regmap, MCHP_PDMC_ISR, &tmp);
647 }
648 
649 static int mchp_pdmc_trigger(struct snd_pcm_substream *substream,
650 			     int cmd, struct snd_soc_dai *dai)
651 {
652 	struct mchp_pdmc *dd = snd_soc_dai_get_drvdata(dai);
653 	struct snd_soc_component *cpu = dai->component;
654 #ifdef DEBUG
655 	u32 val;
656 #endif
657 
658 	switch (cmd) {
659 	case SNDRV_PCM_TRIGGER_RESUME:
660 	case SNDRV_PCM_TRIGGER_START:
661 	case SNDRV_PCM_TRIGGER_PAUSE_RELEASE:
662 		snd_soc_component_update_bits(cpu, MCHP_PDMC_MR,
663 					      MCHP_PDMC_MR_PDMCEN_MASK,
664 					      dd->pdmcen);
665 
666 		mchp_pdmc_noise_filter_workaround(dd);
667 
668 		/* Enable interrupts. */
669 		regmap_write(dd->regmap, MCHP_PDMC_IER, dd->suspend_irq |
670 			     MCHP_PDMC_IR_RXOVR | MCHP_PDMC_IR_RXUDR);
671 		dd->suspend_irq = 0;
672 		break;
673 	case SNDRV_PCM_TRIGGER_SUSPEND:
674 		regmap_read(dd->regmap, MCHP_PDMC_IMR, &dd->suspend_irq);
675 		fallthrough;
676 	case SNDRV_PCM_TRIGGER_STOP:
677 		/* Disable overrun and underrun error interrupts */
678 		regmap_write(dd->regmap, MCHP_PDMC_IDR, dd->suspend_irq |
679 			     MCHP_PDMC_IR_RXOVR | MCHP_PDMC_IR_RXUDR);
680 		fallthrough;
681 	case SNDRV_PCM_TRIGGER_PAUSE_PUSH:
682 		snd_soc_component_update_bits(cpu, MCHP_PDMC_MR,
683 					      MCHP_PDMC_MR_PDMCEN_MASK, 0);
684 		break;
685 	default:
686 		return -EINVAL;
687 	}
688 
689 #ifdef DEBUG
690 	regmap_read(dd->regmap, MCHP_PDMC_MR, &val);
691 	dev_dbg(dd->dev, "MR (0x%02x): 0x%08x\n", MCHP_PDMC_MR, val);
692 	regmap_read(dd->regmap, MCHP_PDMC_CFGR, &val);
693 	dev_dbg(dd->dev, "CFGR (0x%02x): 0x%08x\n", MCHP_PDMC_CFGR, val);
694 	regmap_read(dd->regmap, MCHP_PDMC_IMR, &val);
695 	dev_dbg(dd->dev, "IMR (0x%02x): 0x%08x\n", MCHP_PDMC_IMR, val);
696 #endif
697 
698 	return 0;
699 }
700 
701 static int mchp_pdmc_add_chmap_ctls(struct snd_pcm *pcm, struct mchp_pdmc *dd)
702 {
703 	struct mchp_pdmc_chmap *info;
704 	struct snd_kcontrol_new knew = {
705 		.iface = SNDRV_CTL_ELEM_IFACE_PCM,
706 		.access = SNDRV_CTL_ELEM_ACCESS_READWRITE |
707 			SNDRV_CTL_ELEM_ACCESS_TLV_READ |
708 			SNDRV_CTL_ELEM_ACCESS_TLV_CALLBACK,
709 		.info = mchp_pdmc_chmap_ctl_info,
710 		.get = mchp_pdmc_chmap_ctl_get,
711 		.put = mchp_pdmc_chmap_ctl_put,
712 		.tlv.c = mchp_pdmc_chmap_ctl_tlv,
713 	};
714 	int err;
715 
716 	if (WARN_ON(pcm->streams[SNDRV_PCM_STREAM_CAPTURE].chmap_kctl))
717 		return -EBUSY;
718 	info = kzalloc(sizeof(*info), GFP_KERNEL);
719 	if (!info)
720 		return -ENOMEM;
721 	info->pcm = pcm;
722 	info->dd = dd;
723 	info->chmap = mchp_pdmc_std_chmaps;
724 	knew.name = "Capture Channel Map";
725 	knew.device = pcm->device;
726 	knew.count = pcm->streams[SNDRV_PCM_STREAM_CAPTURE].substream_count;
727 	info->kctl = snd_ctl_new1(&knew, info);
728 	if (!info->kctl) {
729 		kfree(info);
730 		return -ENOMEM;
731 	}
732 	info->kctl->private_free = mchp_pdmc_chmap_ctl_private_free;
733 	err = snd_ctl_add(pcm->card, info->kctl);
734 	if (err < 0)
735 		return err;
736 	pcm->streams[SNDRV_PCM_STREAM_CAPTURE].chmap_kctl = info->kctl;
737 	return 0;
738 }
739 
740 static int mchp_pdmc_pcm_new(struct snd_soc_pcm_runtime *rtd,
741 			     struct snd_soc_dai *dai)
742 {
743 	struct mchp_pdmc *dd = snd_soc_dai_get_drvdata(dai);
744 	int ret;
745 
746 	ret = mchp_pdmc_add_chmap_ctls(rtd->pcm, dd);
747 	if (ret < 0)
748 		dev_err(dd->dev, "failed to add channel map controls: %d\n", ret);
749 
750 	return ret;
751 }
752 
753 static const struct snd_soc_dai_ops mchp_pdmc_dai_ops = {
754 	.probe		= mchp_pdmc_dai_probe,
755 	.set_fmt	= mchp_pdmc_set_fmt,
756 	.startup	= mchp_pdmc_startup,
757 	.hw_params	= mchp_pdmc_hw_params,
758 	.trigger	= mchp_pdmc_trigger,
759 	.pcm_new	= &mchp_pdmc_pcm_new,
760 };
761 
762 static struct snd_soc_dai_driver mchp_pdmc_dai = {
763 	.capture = {
764 		.stream_name	= "Capture",
765 		.channels_min	= 1,
766 		.channels_max	= 4,
767 		.rate_min	= 8000,
768 		.rate_max	= 192000,
769 		.rates		= SNDRV_PCM_RATE_KNOT,
770 		.formats	= SNDRV_PCM_FMTBIT_S24_LE,
771 	},
772 	.ops = &mchp_pdmc_dai_ops,
773 };
774 
775 /* PDMC interrupt handler */
776 static irqreturn_t mchp_pdmc_interrupt(int irq, void *dev_id)
777 {
778 	struct mchp_pdmc *dd = dev_id;
779 	u32 isr, msr, pending;
780 	irqreturn_t ret = IRQ_NONE;
781 
782 	regmap_read(dd->regmap, MCHP_PDMC_ISR, &isr);
783 	regmap_read(dd->regmap, MCHP_PDMC_IMR, &msr);
784 
785 	pending = isr & msr;
786 	dev_dbg(dd->dev, "ISR (0x%02x): 0x%08x, IMR (0x%02x): 0x%08x, pending: 0x%08x\n",
787 		MCHP_PDMC_ISR, isr, MCHP_PDMC_IMR, msr, pending);
788 	if (!pending)
789 		return IRQ_NONE;
790 
791 	if (pending & MCHP_PDMC_IR_RXUDR) {
792 		dev_warn(dd->dev, "underrun detected\n");
793 		regmap_write(dd->regmap, MCHP_PDMC_IDR, MCHP_PDMC_IR_RXUDR);
794 		ret = IRQ_HANDLED;
795 	}
796 	if (pending & MCHP_PDMC_IR_RXOVR) {
797 		dev_warn(dd->dev, "overrun detected\n");
798 		regmap_write(dd->regmap, MCHP_PDMC_IDR, MCHP_PDMC_IR_RXOVR);
799 		ret = IRQ_HANDLED;
800 	}
801 
802 	return ret;
803 }
804 
805 /* regmap configuration */
806 static bool mchp_pdmc_readable_reg(struct device *dev, unsigned int reg)
807 {
808 	switch (reg) {
809 	case MCHP_PDMC_MR:
810 	case MCHP_PDMC_CFGR:
811 	case MCHP_PDMC_IMR:
812 	case MCHP_PDMC_ISR:
813 	case MCHP_PDMC_RHR:
814 	case MCHP_PDMC_VER:
815 		return true;
816 	default:
817 		return false;
818 	}
819 }
820 
821 static bool mchp_pdmc_writeable_reg(struct device *dev, unsigned int reg)
822 {
823 	switch (reg) {
824 	case MCHP_PDMC_CR:
825 	case MCHP_PDMC_MR:
826 	case MCHP_PDMC_CFGR:
827 	case MCHP_PDMC_IER:
828 	case MCHP_PDMC_IDR:
829 		return true;
830 	default:
831 		return false;
832 	}
833 }
834 
835 static bool mchp_pdmc_volatile_reg(struct device *dev, unsigned int reg)
836 {
837 	switch (reg) {
838 	case MCHP_PDMC_ISR:
839 	case MCHP_PDMC_RHR:
840 		return true;
841 	default:
842 		return false;
843 	}
844 }
845 
846 static bool mchp_pdmc_precious_reg(struct device *dev, unsigned int reg)
847 {
848 	switch (reg) {
849 	case MCHP_PDMC_RHR:
850 	case MCHP_PDMC_ISR:
851 		return true;
852 	default:
853 		return false;
854 	}
855 }
856 
857 static const struct regmap_config mchp_pdmc_regmap_config = {
858 	.reg_bits	= 32,
859 	.reg_stride	= 4,
860 	.val_bits	= 32,
861 	.max_register	= MCHP_PDMC_VER,
862 	.readable_reg	= mchp_pdmc_readable_reg,
863 	.writeable_reg	= mchp_pdmc_writeable_reg,
864 	.precious_reg	= mchp_pdmc_precious_reg,
865 	.volatile_reg	= mchp_pdmc_volatile_reg,
866 	.cache_type	= REGCACHE_FLAT,
867 };
868 
869 static int mchp_pdmc_dt_init(struct mchp_pdmc *dd)
870 {
871 	struct device_node *np = dd->dev->of_node;
872 	bool mic_ch[MCHP_PDMC_DS_NO][MCHP_PDMC_EDGE_NO] = {0};
873 	int i;
874 	int ret;
875 
876 	if (!np) {
877 		dev_err(dd->dev, "device node not found\n");
878 		return -EINVAL;
879 	}
880 
881 	dd->mic_no = of_property_count_u32_elems(np, "microchip,mic-pos");
882 	if (dd->mic_no < 0) {
883 		dev_err(dd->dev, "failed to get microchip,mic-pos: %d",
884 			dd->mic_no);
885 		return dd->mic_no;
886 	}
887 	if (!dd->mic_no || dd->mic_no % 2 ||
888 	    dd->mic_no / 2 > MCHP_PDMC_MAX_CHANNELS) {
889 		dev_err(dd->dev, "invalid array length for microchip,mic-pos: %d",
890 			dd->mic_no);
891 		return -EINVAL;
892 	}
893 
894 	dd->mic_no /= 2;
895 
896 	dev_info(dd->dev, "%d PDM microphones declared\n", dd->mic_no);
897 
898 	/*
899 	 * by default, we consider the order of microphones in
900 	 * microchip,mic-pos to be the same with the channel mapping;
901 	 * 1st microphone channel 0, 2nd microphone channel 1, etc.
902 	 */
903 	for (i = 0; i < dd->mic_no; i++) {
904 		int ds;
905 		int edge;
906 
907 		ret = of_property_read_u32_index(np, "microchip,mic-pos", i * 2,
908 						 &ds);
909 		if (ret) {
910 			dev_err(dd->dev,
911 				"failed to get value no %d value from microchip,mic-pos: %d",
912 				i * 2, ret);
913 			return ret;
914 		}
915 		if (ds >= MCHP_PDMC_DS_NO) {
916 			dev_err(dd->dev,
917 				"invalid DS index in microchip,mic-pos array: %d",
918 				ds);
919 			return -EINVAL;
920 		}
921 
922 		ret = of_property_read_u32_index(np, "microchip,mic-pos", i * 2 + 1,
923 						 &edge);
924 		if (ret) {
925 			dev_err(dd->dev,
926 				"failed to get value no %d value from microchip,mic-pos: %d",
927 				i * 2 + 1, ret);
928 			return ret;
929 		}
930 
931 		if (edge != MCHP_PDMC_CLK_POSITIVE &&
932 		    edge != MCHP_PDMC_CLK_NEGATIVE) {
933 			dev_err(dd->dev,
934 				"invalid edge in microchip,mic-pos array: %d", edge);
935 			return -EINVAL;
936 		}
937 		if (mic_ch[ds][edge]) {
938 			dev_err(dd->dev,
939 				"duplicated mic (DS %d, edge %d) in microchip,mic-pos array",
940 				ds, edge);
941 			return -EINVAL;
942 		}
943 		mic_ch[ds][edge] = true;
944 		dd->channel_mic_map[i].ds_pos = ds;
945 		dd->channel_mic_map[i].clk_edge = edge;
946 	}
947 
948 	dd->startup_delay_us = 150000;
949 	of_property_read_u32(np, "microchip,startup-delay-us", &dd->startup_delay_us);
950 
951 	return 0;
952 }
953 
954 /* used to clean the channel index found on RHR's MSB */
955 static int mchp_pdmc_process(struct snd_pcm_substream *substream,
956 			     int channel, unsigned long hwoff,
957 			     unsigned long bytes)
958 {
959 	struct snd_pcm_runtime *runtime = substream->runtime;
960 	u8 *dma_ptr = runtime->dma_area + hwoff +
961 		      channel * (runtime->dma_bytes / runtime->channels);
962 	u8 *dma_ptr_end = dma_ptr + bytes;
963 	unsigned int sample_size = samples_to_bytes(runtime, 1);
964 
965 	for (; dma_ptr < dma_ptr_end; dma_ptr += sample_size)
966 		*dma_ptr = 0;
967 
968 	return 0;
969 }
970 
971 static struct snd_dmaengine_pcm_config mchp_pdmc_config = {
972 	.process = mchp_pdmc_process,
973 	.prepare_slave_config = snd_dmaengine_pcm_prepare_slave_config,
974 };
975 
976 static int mchp_pdmc_runtime_suspend(struct device *dev)
977 {
978 	struct mchp_pdmc *dd = dev_get_drvdata(dev);
979 
980 	regcache_cache_only(dd->regmap, true);
981 
982 	clk_disable_unprepare(dd->gclk);
983 	clk_disable_unprepare(dd->pclk);
984 
985 	return 0;
986 }
987 
988 static int mchp_pdmc_runtime_resume(struct device *dev)
989 {
990 	struct mchp_pdmc *dd = dev_get_drvdata(dev);
991 	int ret;
992 
993 	ret = clk_prepare_enable(dd->pclk);
994 	if (ret) {
995 		dev_err(dd->dev,
996 			"failed to enable the peripheral clock: %d\n", ret);
997 		return ret;
998 	}
999 	ret = clk_prepare_enable(dd->gclk);
1000 	if (ret) {
1001 		dev_err(dd->dev,
1002 			"failed to enable generic clock: %d\n", ret);
1003 		goto disable_pclk;
1004 	}
1005 
1006 	regcache_cache_only(dd->regmap, false);
1007 	regcache_mark_dirty(dd->regmap);
1008 	ret = regcache_sync(dd->regmap);
1009 	if (ret) {
1010 		regcache_cache_only(dd->regmap, true);
1011 		clk_disable_unprepare(dd->gclk);
1012 disable_pclk:
1013 		clk_disable_unprepare(dd->pclk);
1014 	}
1015 
1016 	return ret;
1017 }
1018 
1019 static int mchp_pdmc_probe(struct platform_device *pdev)
1020 {
1021 	struct device *dev = &pdev->dev;
1022 	struct mchp_pdmc *dd;
1023 	struct resource *res;
1024 	void __iomem *io_base;
1025 	u32 version;
1026 	int irq;
1027 	int ret;
1028 
1029 	dd = devm_kzalloc(dev, sizeof(*dd), GFP_KERNEL);
1030 	if (!dd)
1031 		return -ENOMEM;
1032 
1033 	dd->dev = &pdev->dev;
1034 	ret = mchp_pdmc_dt_init(dd);
1035 	if (ret < 0)
1036 		return ret;
1037 
1038 	irq = platform_get_irq(pdev, 0);
1039 	if (irq < 0)
1040 		return irq;
1041 
1042 	dd->pclk = devm_clk_get(dev, "pclk");
1043 	if (IS_ERR(dd->pclk)) {
1044 		ret = PTR_ERR(dd->pclk);
1045 		dev_err(dev, "failed to get peripheral clock: %d\n", ret);
1046 		return ret;
1047 	}
1048 
1049 	dd->gclk = devm_clk_get(dev, "gclk");
1050 	if (IS_ERR(dd->gclk)) {
1051 		ret = PTR_ERR(dd->gclk);
1052 		dev_err(dev, "failed to get GCK: %d\n", ret);
1053 		return ret;
1054 	}
1055 
1056 	io_base = devm_platform_get_and_ioremap_resource(pdev, 0, &res);
1057 	if (IS_ERR(io_base)) {
1058 		ret = PTR_ERR(io_base);
1059 		dev_err(dev, "failed to remap register memory: %d\n", ret);
1060 		return ret;
1061 	}
1062 
1063 	dd->regmap = devm_regmap_init_mmio(dev, io_base,
1064 					   &mchp_pdmc_regmap_config);
1065 	if (IS_ERR(dd->regmap)) {
1066 		ret = PTR_ERR(dd->regmap);
1067 		dev_err(dev, "failed to init register map: %d\n", ret);
1068 		return ret;
1069 	}
1070 
1071 	ret = devm_request_irq(dev, irq, mchp_pdmc_interrupt, 0,
1072 			       dev_name(&pdev->dev), dd);
1073 	if (ret < 0) {
1074 		dev_err(dev, "can't register ISR for IRQ %u (ret=%i)\n",
1075 			irq, ret);
1076 		return ret;
1077 	}
1078 
1079 	/* by default audio filter is enabled and the SINC Filter order
1080 	 * will be set to the recommended value, 3
1081 	 */
1082 	dd->audio_filter_en = true;
1083 	dd->sinc_order = 3;
1084 
1085 	dd->addr.addr = (dma_addr_t)res->start + MCHP_PDMC_RHR;
1086 	platform_set_drvdata(pdev, dd);
1087 
1088 	pm_runtime_enable(dd->dev);
1089 	if (!pm_runtime_enabled(dd->dev)) {
1090 		ret = mchp_pdmc_runtime_resume(dd->dev);
1091 		if (ret)
1092 			return ret;
1093 	}
1094 
1095 	/* register platform */
1096 	ret = devm_snd_dmaengine_pcm_register(dev, &mchp_pdmc_config, 0);
1097 	if (ret) {
1098 		dev_err(dev, "could not register platform: %d\n", ret);
1099 		goto pm_runtime_suspend;
1100 	}
1101 
1102 	ret = devm_snd_soc_register_component(dev, &mchp_pdmc_dai_component,
1103 					      &mchp_pdmc_dai, 1);
1104 	if (ret) {
1105 		dev_err(dev, "could not register CPU DAI: %d\n", ret);
1106 		goto pm_runtime_suspend;
1107 	}
1108 
1109 	/* print IP version */
1110 	regmap_read(dd->regmap, MCHP_PDMC_VER, &version);
1111 	dev_info(dd->dev, "hw version: %#lx\n",
1112 		 version & MCHP_PDMC_VER_VERSION);
1113 
1114 	return 0;
1115 
1116 pm_runtime_suspend:
1117 	if (!pm_runtime_status_suspended(dd->dev))
1118 		mchp_pdmc_runtime_suspend(dd->dev);
1119 	pm_runtime_disable(dd->dev);
1120 
1121 	return ret;
1122 }
1123 
1124 static void mchp_pdmc_remove(struct platform_device *pdev)
1125 {
1126 	struct mchp_pdmc *dd = platform_get_drvdata(pdev);
1127 
1128 	if (!pm_runtime_status_suspended(dd->dev))
1129 		mchp_pdmc_runtime_suspend(dd->dev);
1130 
1131 	pm_runtime_disable(dd->dev);
1132 }
1133 
1134 static const struct of_device_id mchp_pdmc_of_match[] = {
1135 	{
1136 		.compatible = "microchip,sama7g5-pdmc",
1137 	}, {
1138 		/* sentinel */
1139 	}
1140 };
1141 MODULE_DEVICE_TABLE(of, mchp_pdmc_of_match);
1142 
1143 static const struct dev_pm_ops mchp_pdmc_pm_ops = {
1144 	SYSTEM_SLEEP_PM_OPS(pm_runtime_force_suspend, pm_runtime_force_resume)
1145 	RUNTIME_PM_OPS(mchp_pdmc_runtime_suspend, mchp_pdmc_runtime_resume,
1146 		       NULL)
1147 };
1148 
1149 static struct platform_driver mchp_pdmc_driver = {
1150 	.driver	= {
1151 		.name		= "mchp-pdmc",
1152 		.of_match_table	= of_match_ptr(mchp_pdmc_of_match),
1153 		.pm		= pm_ptr(&mchp_pdmc_pm_ops),
1154 	},
1155 	.probe	= mchp_pdmc_probe,
1156 	.remove_new = mchp_pdmc_remove,
1157 };
1158 module_platform_driver(mchp_pdmc_driver);
1159 
1160 MODULE_DESCRIPTION("Microchip PDMC driver under ALSA SoC architecture");
1161 MODULE_AUTHOR("Codrin Ciubotariu <codrin.ciubotariu@microchip.com>");
1162 MODULE_LICENSE("GPL v2");
1163