xref: /linux/sound/usb/stream.c (revision 0889d07f3e4b171c453b2aaf2b257f9074cdf624)
1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3  */
4 
5 
6 #include <linux/init.h>
7 #include <linux/slab.h>
8 #include <linux/usb.h>
9 #include <linux/usb/audio.h>
10 #include <linux/usb/audio-v2.h>
11 #include <linux/usb/audio-v3.h>
12 
13 #include <sound/core.h>
14 #include <sound/pcm.h>
15 #include <sound/control.h>
16 #include <sound/tlv.h>
17 
18 #include "usbaudio.h"
19 #include "card.h"
20 #include "proc.h"
21 #include "quirks.h"
22 #include "endpoint.h"
23 #include "pcm.h"
24 #include "helper.h"
25 #include "format.h"
26 #include "clock.h"
27 #include "stream.h"
28 #include "power.h"
29 #include "media.h"
30 
31 static void audioformat_free(struct audioformat *fp)
32 {
33 	list_del(&fp->list); /* unlink for avoiding double-free */
34 	kfree(fp->rate_table);
35 	kfree(fp->chmap);
36 	kfree(fp);
37 }
38 
39 /*
40  * free a substream
41  */
42 static void free_substream(struct snd_usb_substream *subs)
43 {
44 	struct audioformat *fp, *n;
45 
46 	if (!subs->num_formats)
47 		return; /* not initialized */
48 	list_for_each_entry_safe(fp, n, &subs->fmt_list, list)
49 		audioformat_free(fp);
50 	kfree(subs->rate_list.list);
51 	kfree(subs->str_pd);
52 	snd_media_stream_delete(subs);
53 }
54 
55 
56 /*
57  * free a usb stream instance
58  */
59 static void snd_usb_audio_stream_free(struct snd_usb_stream *stream)
60 {
61 	free_substream(&stream->substream[0]);
62 	free_substream(&stream->substream[1]);
63 	list_del(&stream->list);
64 	kfree(stream);
65 }
66 
67 static void snd_usb_audio_pcm_free(struct snd_pcm *pcm)
68 {
69 	struct snd_usb_stream *stream = pcm->private_data;
70 	if (stream) {
71 		stream->pcm = NULL;
72 		snd_usb_audio_stream_free(stream);
73 	}
74 }
75 
76 /*
77  * initialize the substream instance.
78  */
79 
80 static void snd_usb_init_substream(struct snd_usb_stream *as,
81 				   int stream,
82 				   struct audioformat *fp,
83 				   struct snd_usb_power_domain *pd)
84 {
85 	struct snd_usb_substream *subs = &as->substream[stream];
86 
87 	INIT_LIST_HEAD(&subs->fmt_list);
88 	spin_lock_init(&subs->lock);
89 
90 	subs->stream = as;
91 	subs->direction = stream;
92 	subs->dev = as->chip->dev;
93 	subs->txfr_quirk = as->chip->txfr_quirk;
94 	subs->tx_length_quirk = as->chip->tx_length_quirk;
95 	subs->speed = snd_usb_get_speed(subs->dev);
96 	subs->pkt_offset_adj = 0;
97 
98 	snd_usb_set_pcm_ops(as->pcm, stream);
99 
100 	list_add_tail(&fp->list, &subs->fmt_list);
101 	subs->formats |= fp->formats;
102 	subs->num_formats++;
103 	subs->fmt_type = fp->fmt_type;
104 	subs->ep_num = fp->endpoint;
105 	if (fp->channels > subs->channels_max)
106 		subs->channels_max = fp->channels;
107 
108 	if (pd) {
109 		subs->str_pd = pd;
110 		/* Initialize Power Domain to idle status D1 */
111 		snd_usb_power_domain_set(subs->stream->chip, pd,
112 					 UAC3_PD_STATE_D1);
113 	}
114 
115 	snd_usb_preallocate_buffer(subs);
116 }
117 
118 /* kctl callbacks for usb-audio channel maps */
119 static int usb_chmap_ctl_info(struct snd_kcontrol *kcontrol,
120 			      struct snd_ctl_elem_info *uinfo)
121 {
122 	struct snd_pcm_chmap *info = snd_kcontrol_chip(kcontrol);
123 	struct snd_usb_substream *subs = info->private_data;
124 
125 	uinfo->type = SNDRV_CTL_ELEM_TYPE_INTEGER;
126 	uinfo->count = subs->channels_max;
127 	uinfo->value.integer.min = 0;
128 	uinfo->value.integer.max = SNDRV_CHMAP_LAST;
129 	return 0;
130 }
131 
132 /* check whether a duplicated entry exists in the audiofmt list */
133 static bool have_dup_chmap(struct snd_usb_substream *subs,
134 			   struct audioformat *fp)
135 {
136 	struct audioformat *prev = fp;
137 
138 	list_for_each_entry_continue_reverse(prev, &subs->fmt_list, list) {
139 		if (prev->chmap &&
140 		    !memcmp(prev->chmap, fp->chmap, sizeof(*fp->chmap)))
141 			return true;
142 	}
143 	return false;
144 }
145 
146 static int usb_chmap_ctl_tlv(struct snd_kcontrol *kcontrol, int op_flag,
147 			     unsigned int size, unsigned int __user *tlv)
148 {
149 	struct snd_pcm_chmap *info = snd_kcontrol_chip(kcontrol);
150 	struct snd_usb_substream *subs = info->private_data;
151 	struct audioformat *fp;
152 	unsigned int __user *dst;
153 	int count = 0;
154 
155 	if (size < 8)
156 		return -ENOMEM;
157 	if (put_user(SNDRV_CTL_TLVT_CONTAINER, tlv))
158 		return -EFAULT;
159 	size -= 8;
160 	dst = tlv + 2;
161 	list_for_each_entry(fp, &subs->fmt_list, list) {
162 		int i, ch_bytes;
163 
164 		if (!fp->chmap)
165 			continue;
166 		if (have_dup_chmap(subs, fp))
167 			continue;
168 		/* copy the entry */
169 		ch_bytes = fp->chmap->channels * 4;
170 		if (size < 8 + ch_bytes)
171 			return -ENOMEM;
172 		if (put_user(SNDRV_CTL_TLVT_CHMAP_FIXED, dst) ||
173 		    put_user(ch_bytes, dst + 1))
174 			return -EFAULT;
175 		dst += 2;
176 		for (i = 0; i < fp->chmap->channels; i++, dst++) {
177 			if (put_user(fp->chmap->map[i], dst))
178 				return -EFAULT;
179 		}
180 
181 		count += 8 + ch_bytes;
182 		size -= 8 + ch_bytes;
183 	}
184 	if (put_user(count, tlv + 1))
185 		return -EFAULT;
186 	return 0;
187 }
188 
189 static int usb_chmap_ctl_get(struct snd_kcontrol *kcontrol,
190 			     struct snd_ctl_elem_value *ucontrol)
191 {
192 	struct snd_pcm_chmap *info = snd_kcontrol_chip(kcontrol);
193 	struct snd_usb_substream *subs = info->private_data;
194 	struct snd_pcm_chmap_elem *chmap = NULL;
195 	int i;
196 
197 	memset(ucontrol->value.integer.value, 0,
198 	       sizeof(ucontrol->value.integer.value));
199 	if (subs->cur_audiofmt)
200 		chmap = subs->cur_audiofmt->chmap;
201 	if (chmap) {
202 		for (i = 0; i < chmap->channels; i++)
203 			ucontrol->value.integer.value[i] = chmap->map[i];
204 	}
205 	return 0;
206 }
207 
208 /* create a chmap kctl assigned to the given USB substream */
209 static int add_chmap(struct snd_pcm *pcm, int stream,
210 		     struct snd_usb_substream *subs)
211 {
212 	struct audioformat *fp;
213 	struct snd_pcm_chmap *chmap;
214 	struct snd_kcontrol *kctl;
215 	int err;
216 
217 	list_for_each_entry(fp, &subs->fmt_list, list)
218 		if (fp->chmap)
219 			goto ok;
220 	/* no chmap is found */
221 	return 0;
222 
223  ok:
224 	err = snd_pcm_add_chmap_ctls(pcm, stream, NULL, 0, 0, &chmap);
225 	if (err < 0)
226 		return err;
227 
228 	/* override handlers */
229 	chmap->private_data = subs;
230 	kctl = chmap->kctl;
231 	kctl->info = usb_chmap_ctl_info;
232 	kctl->get = usb_chmap_ctl_get;
233 	kctl->tlv.c = usb_chmap_ctl_tlv;
234 
235 	return 0;
236 }
237 
238 /* convert from USB ChannelConfig bits to ALSA chmap element */
239 static struct snd_pcm_chmap_elem *convert_chmap(int channels, unsigned int bits,
240 						int protocol)
241 {
242 	static unsigned int uac1_maps[] = {
243 		SNDRV_CHMAP_FL,		/* left front */
244 		SNDRV_CHMAP_FR,		/* right front */
245 		SNDRV_CHMAP_FC,		/* center front */
246 		SNDRV_CHMAP_LFE,	/* LFE */
247 		SNDRV_CHMAP_SL,		/* left surround */
248 		SNDRV_CHMAP_SR,		/* right surround */
249 		SNDRV_CHMAP_FLC,	/* left of center */
250 		SNDRV_CHMAP_FRC,	/* right of center */
251 		SNDRV_CHMAP_RC,		/* surround */
252 		SNDRV_CHMAP_SL,		/* side left */
253 		SNDRV_CHMAP_SR,		/* side right */
254 		SNDRV_CHMAP_TC,		/* top */
255 		0 /* terminator */
256 	};
257 	static unsigned int uac2_maps[] = {
258 		SNDRV_CHMAP_FL,		/* front left */
259 		SNDRV_CHMAP_FR,		/* front right */
260 		SNDRV_CHMAP_FC,		/* front center */
261 		SNDRV_CHMAP_LFE,	/* LFE */
262 		SNDRV_CHMAP_RL,		/* back left */
263 		SNDRV_CHMAP_RR,		/* back right */
264 		SNDRV_CHMAP_FLC,	/* front left of center */
265 		SNDRV_CHMAP_FRC,	/* front right of center */
266 		SNDRV_CHMAP_RC,		/* back center */
267 		SNDRV_CHMAP_SL,		/* side left */
268 		SNDRV_CHMAP_SR,		/* side right */
269 		SNDRV_CHMAP_TC,		/* top center */
270 		SNDRV_CHMAP_TFL,	/* top front left */
271 		SNDRV_CHMAP_TFC,	/* top front center */
272 		SNDRV_CHMAP_TFR,	/* top front right */
273 		SNDRV_CHMAP_TRL,	/* top back left */
274 		SNDRV_CHMAP_TRC,	/* top back center */
275 		SNDRV_CHMAP_TRR,	/* top back right */
276 		SNDRV_CHMAP_TFLC,	/* top front left of center */
277 		SNDRV_CHMAP_TFRC,	/* top front right of center */
278 		SNDRV_CHMAP_LLFE,	/* left LFE */
279 		SNDRV_CHMAP_RLFE,	/* right LFE */
280 		SNDRV_CHMAP_TSL,	/* top side left */
281 		SNDRV_CHMAP_TSR,	/* top side right */
282 		SNDRV_CHMAP_BC,		/* bottom center */
283 		SNDRV_CHMAP_RLC,	/* back left of center */
284 		SNDRV_CHMAP_RRC,	/* back right of center */
285 		0 /* terminator */
286 	};
287 	struct snd_pcm_chmap_elem *chmap;
288 	const unsigned int *maps;
289 	int c;
290 
291 	if (channels > ARRAY_SIZE(chmap->map))
292 		return NULL;
293 
294 	chmap = kzalloc(sizeof(*chmap), GFP_KERNEL);
295 	if (!chmap)
296 		return NULL;
297 
298 	maps = protocol == UAC_VERSION_2 ? uac2_maps : uac1_maps;
299 	chmap->channels = channels;
300 	c = 0;
301 
302 	if (bits) {
303 		for (; bits && *maps; maps++, bits >>= 1)
304 			if (bits & 1)
305 				chmap->map[c++] = *maps;
306 	} else {
307 		/* If we're missing wChannelConfig, then guess something
308 		    to make sure the channel map is not skipped entirely */
309 		if (channels == 1)
310 			chmap->map[c++] = SNDRV_CHMAP_MONO;
311 		else
312 			for (; c < channels && *maps; maps++)
313 				chmap->map[c++] = *maps;
314 	}
315 
316 	for (; c < channels; c++)
317 		chmap->map[c] = SNDRV_CHMAP_UNKNOWN;
318 
319 	return chmap;
320 }
321 
322 /* UAC3 device stores channels information in Cluster Descriptors */
323 static struct
324 snd_pcm_chmap_elem *convert_chmap_v3(struct uac3_cluster_header_descriptor
325 								*cluster)
326 {
327 	unsigned int channels = cluster->bNrChannels;
328 	struct snd_pcm_chmap_elem *chmap;
329 	void *p = cluster;
330 	int len, c;
331 
332 	if (channels > ARRAY_SIZE(chmap->map))
333 		return NULL;
334 
335 	chmap = kzalloc(sizeof(*chmap), GFP_KERNEL);
336 	if (!chmap)
337 		return NULL;
338 
339 	len = le16_to_cpu(cluster->wLength);
340 	c = 0;
341 	p += sizeof(struct uac3_cluster_header_descriptor);
342 
343 	while (((p - (void *)cluster) < len) && (c < channels)) {
344 		struct uac3_cluster_segment_descriptor *cs_desc = p;
345 		u16 cs_len;
346 		u8 cs_type;
347 
348 		cs_len = le16_to_cpu(cs_desc->wLength);
349 		cs_type = cs_desc->bSegmentType;
350 
351 		if (cs_type == UAC3_CHANNEL_INFORMATION) {
352 			struct uac3_cluster_information_segment_descriptor *is = p;
353 			unsigned char map;
354 
355 			/*
356 			 * TODO: this conversion is not complete, update it
357 			 * after adding UAC3 values to asound.h
358 			 */
359 			switch (is->bChRelationship) {
360 			case UAC3_CH_MONO:
361 				map = SNDRV_CHMAP_MONO;
362 				break;
363 			case UAC3_CH_LEFT:
364 			case UAC3_CH_FRONT_LEFT:
365 			case UAC3_CH_HEADPHONE_LEFT:
366 				map = SNDRV_CHMAP_FL;
367 				break;
368 			case UAC3_CH_RIGHT:
369 			case UAC3_CH_FRONT_RIGHT:
370 			case UAC3_CH_HEADPHONE_RIGHT:
371 				map = SNDRV_CHMAP_FR;
372 				break;
373 			case UAC3_CH_FRONT_CENTER:
374 				map = SNDRV_CHMAP_FC;
375 				break;
376 			case UAC3_CH_FRONT_LEFT_OF_CENTER:
377 				map = SNDRV_CHMAP_FLC;
378 				break;
379 			case UAC3_CH_FRONT_RIGHT_OF_CENTER:
380 				map = SNDRV_CHMAP_FRC;
381 				break;
382 			case UAC3_CH_SIDE_LEFT:
383 				map = SNDRV_CHMAP_SL;
384 				break;
385 			case UAC3_CH_SIDE_RIGHT:
386 				map = SNDRV_CHMAP_SR;
387 				break;
388 			case UAC3_CH_BACK_LEFT:
389 				map = SNDRV_CHMAP_RL;
390 				break;
391 			case UAC3_CH_BACK_RIGHT:
392 				map = SNDRV_CHMAP_RR;
393 				break;
394 			case UAC3_CH_BACK_CENTER:
395 				map = SNDRV_CHMAP_RC;
396 				break;
397 			case UAC3_CH_BACK_LEFT_OF_CENTER:
398 				map = SNDRV_CHMAP_RLC;
399 				break;
400 			case UAC3_CH_BACK_RIGHT_OF_CENTER:
401 				map = SNDRV_CHMAP_RRC;
402 				break;
403 			case UAC3_CH_TOP_CENTER:
404 				map = SNDRV_CHMAP_TC;
405 				break;
406 			case UAC3_CH_TOP_FRONT_LEFT:
407 				map = SNDRV_CHMAP_TFL;
408 				break;
409 			case UAC3_CH_TOP_FRONT_RIGHT:
410 				map = SNDRV_CHMAP_TFR;
411 				break;
412 			case UAC3_CH_TOP_FRONT_CENTER:
413 				map = SNDRV_CHMAP_TFC;
414 				break;
415 			case UAC3_CH_TOP_FRONT_LOC:
416 				map = SNDRV_CHMAP_TFLC;
417 				break;
418 			case UAC3_CH_TOP_FRONT_ROC:
419 				map = SNDRV_CHMAP_TFRC;
420 				break;
421 			case UAC3_CH_TOP_SIDE_LEFT:
422 				map = SNDRV_CHMAP_TSL;
423 				break;
424 			case UAC3_CH_TOP_SIDE_RIGHT:
425 				map = SNDRV_CHMAP_TSR;
426 				break;
427 			case UAC3_CH_TOP_BACK_LEFT:
428 				map = SNDRV_CHMAP_TRL;
429 				break;
430 			case UAC3_CH_TOP_BACK_RIGHT:
431 				map = SNDRV_CHMAP_TRR;
432 				break;
433 			case UAC3_CH_TOP_BACK_CENTER:
434 				map = SNDRV_CHMAP_TRC;
435 				break;
436 			case UAC3_CH_BOTTOM_CENTER:
437 				map = SNDRV_CHMAP_BC;
438 				break;
439 			case UAC3_CH_LOW_FREQUENCY_EFFECTS:
440 				map = SNDRV_CHMAP_LFE;
441 				break;
442 			case UAC3_CH_LFE_LEFT:
443 				map = SNDRV_CHMAP_LLFE;
444 				break;
445 			case UAC3_CH_LFE_RIGHT:
446 				map = SNDRV_CHMAP_RLFE;
447 				break;
448 			case UAC3_CH_RELATIONSHIP_UNDEFINED:
449 			default:
450 				map = SNDRV_CHMAP_UNKNOWN;
451 				break;
452 			}
453 			chmap->map[c++] = map;
454 		}
455 		p += cs_len;
456 	}
457 
458 	if (channels < c)
459 		pr_err("%s: channel number mismatch\n", __func__);
460 
461 	chmap->channels = channels;
462 
463 	for (; c < channels; c++)
464 		chmap->map[c] = SNDRV_CHMAP_UNKNOWN;
465 
466 	return chmap;
467 }
468 
469 /*
470  * add this endpoint to the chip instance.
471  * if a stream with the same endpoint already exists, append to it.
472  * if not, create a new pcm stream. note, fp is added to the substream
473  * fmt_list and will be freed on the chip instance release. do not free
474  * fp or do remove it from the substream fmt_list to avoid double-free.
475  */
476 static int __snd_usb_add_audio_stream(struct snd_usb_audio *chip,
477 				      int stream,
478 				      struct audioformat *fp,
479 				      struct snd_usb_power_domain *pd)
480 
481 {
482 	struct snd_usb_stream *as;
483 	struct snd_usb_substream *subs;
484 	struct snd_pcm *pcm;
485 	int err;
486 
487 	list_for_each_entry(as, &chip->pcm_list, list) {
488 		if (as->fmt_type != fp->fmt_type)
489 			continue;
490 		subs = &as->substream[stream];
491 		if (subs->ep_num == fp->endpoint) {
492 			list_add_tail(&fp->list, &subs->fmt_list);
493 			subs->num_formats++;
494 			subs->formats |= fp->formats;
495 			return 0;
496 		}
497 	}
498 	/* look for an empty stream */
499 	list_for_each_entry(as, &chip->pcm_list, list) {
500 		if (as->fmt_type != fp->fmt_type)
501 			continue;
502 		subs = &as->substream[stream];
503 		if (subs->ep_num)
504 			continue;
505 		err = snd_pcm_new_stream(as->pcm, stream, 1);
506 		if (err < 0)
507 			return err;
508 		snd_usb_init_substream(as, stream, fp, pd);
509 		return add_chmap(as->pcm, stream, subs);
510 	}
511 
512 	/* create a new pcm */
513 	as = kzalloc(sizeof(*as), GFP_KERNEL);
514 	if (!as)
515 		return -ENOMEM;
516 	as->pcm_index = chip->pcm_devs;
517 	as->chip = chip;
518 	as->fmt_type = fp->fmt_type;
519 	err = snd_pcm_new(chip->card, "USB Audio", chip->pcm_devs,
520 			  stream == SNDRV_PCM_STREAM_PLAYBACK ? 1 : 0,
521 			  stream == SNDRV_PCM_STREAM_PLAYBACK ? 0 : 1,
522 			  &pcm);
523 	if (err < 0) {
524 		kfree(as);
525 		return err;
526 	}
527 	as->pcm = pcm;
528 	pcm->private_data = as;
529 	pcm->private_free = snd_usb_audio_pcm_free;
530 	pcm->info_flags = 0;
531 	if (chip->pcm_devs > 0)
532 		sprintf(pcm->name, "USB Audio #%d", chip->pcm_devs);
533 	else
534 		strcpy(pcm->name, "USB Audio");
535 
536 	snd_usb_init_substream(as, stream, fp, pd);
537 
538 	/*
539 	 * Keep using head insertion for M-Audio Audiophile USB (tm) which has a
540 	 * fix to swap capture stream order in conf/cards/USB-audio.conf
541 	 */
542 	if (chip->usb_id == USB_ID(0x0763, 0x2003))
543 		list_add(&as->list, &chip->pcm_list);
544 	else
545 		list_add_tail(&as->list, &chip->pcm_list);
546 
547 	chip->pcm_devs++;
548 
549 	snd_usb_proc_pcm_format_add(as);
550 
551 	return add_chmap(pcm, stream, &as->substream[stream]);
552 }
553 
554 int snd_usb_add_audio_stream(struct snd_usb_audio *chip,
555 			     int stream,
556 			     struct audioformat *fp)
557 {
558 	return __snd_usb_add_audio_stream(chip, stream, fp, NULL);
559 }
560 
561 static int snd_usb_add_audio_stream_v3(struct snd_usb_audio *chip,
562 				       int stream,
563 				       struct audioformat *fp,
564 				       struct snd_usb_power_domain *pd)
565 {
566 	return __snd_usb_add_audio_stream(chip, stream, fp, pd);
567 }
568 
569 static int parse_uac_endpoint_attributes(struct snd_usb_audio *chip,
570 					 struct usb_host_interface *alts,
571 					 int protocol, int iface_no)
572 {
573 	/* parsed with a v1 header here. that's ok as we only look at the
574 	 * header first which is the same for both versions */
575 	struct uac_iso_endpoint_descriptor *csep;
576 	struct usb_interface_descriptor *altsd = get_iface_desc(alts);
577 	int attributes = 0;
578 
579 	csep = snd_usb_find_desc(alts->endpoint[0].extra, alts->endpoint[0].extralen, NULL, USB_DT_CS_ENDPOINT);
580 
581 	/* Creamware Noah has this descriptor after the 2nd endpoint */
582 	if (!csep && altsd->bNumEndpoints >= 2)
583 		csep = snd_usb_find_desc(alts->endpoint[1].extra, alts->endpoint[1].extralen, NULL, USB_DT_CS_ENDPOINT);
584 
585 	/*
586 	 * If we can't locate the USB_DT_CS_ENDPOINT descriptor in the extra
587 	 * bytes after the first endpoint, go search the entire interface.
588 	 * Some devices have it directly *before* the standard endpoint.
589 	 */
590 	if (!csep)
591 		csep = snd_usb_find_desc(alts->extra, alts->extralen, NULL, USB_DT_CS_ENDPOINT);
592 
593 	if (!csep || csep->bLength < 7 ||
594 	    csep->bDescriptorSubtype != UAC_EP_GENERAL)
595 		goto error;
596 
597 	if (protocol == UAC_VERSION_1) {
598 		attributes = csep->bmAttributes;
599 	} else if (protocol == UAC_VERSION_2) {
600 		struct uac2_iso_endpoint_descriptor *csep2 =
601 			(struct uac2_iso_endpoint_descriptor *) csep;
602 
603 		if (csep2->bLength < sizeof(*csep2))
604 			goto error;
605 		attributes = csep->bmAttributes & UAC_EP_CS_ATTR_FILL_MAX;
606 
607 		/* emulate the endpoint attributes of a v1 device */
608 		if (csep2->bmControls & UAC2_CONTROL_PITCH)
609 			attributes |= UAC_EP_CS_ATTR_PITCH_CONTROL;
610 	} else { /* UAC_VERSION_3 */
611 		struct uac3_iso_endpoint_descriptor *csep3 =
612 			(struct uac3_iso_endpoint_descriptor *) csep;
613 
614 		if (csep3->bLength < sizeof(*csep3))
615 			goto error;
616 		/* emulate the endpoint attributes of a v1 device */
617 		if (le32_to_cpu(csep3->bmControls) & UAC2_CONTROL_PITCH)
618 			attributes |= UAC_EP_CS_ATTR_PITCH_CONTROL;
619 	}
620 
621 	return attributes;
622 
623  error:
624 	usb_audio_warn(chip,
625 		       "%u:%d : no or invalid class specific endpoint descriptor\n",
626 		       iface_no, altsd->bAlternateSetting);
627 	return 0;
628 }
629 
630 /* find an input terminal descriptor (either UAC1 or UAC2) with the given
631  * terminal id
632  */
633 static void *
634 snd_usb_find_input_terminal_descriptor(struct usb_host_interface *ctrl_iface,
635 				       int terminal_id, int protocol)
636 {
637 	struct uac2_input_terminal_descriptor *term = NULL;
638 
639 	while ((term = snd_usb_find_csint_desc(ctrl_iface->extra,
640 					       ctrl_iface->extralen,
641 					       term, UAC_INPUT_TERMINAL))) {
642 		if (!snd_usb_validate_audio_desc(term, protocol))
643 			continue;
644 		if (term->bTerminalID == terminal_id)
645 			return term;
646 	}
647 
648 	return NULL;
649 }
650 
651 static void *
652 snd_usb_find_output_terminal_descriptor(struct usb_host_interface *ctrl_iface,
653 					int terminal_id, int protocol)
654 {
655 	/* OK to use with both UAC2 and UAC3 */
656 	struct uac2_output_terminal_descriptor *term = NULL;
657 
658 	while ((term = snd_usb_find_csint_desc(ctrl_iface->extra,
659 					       ctrl_iface->extralen,
660 					       term, UAC_OUTPUT_TERMINAL))) {
661 		if (!snd_usb_validate_audio_desc(term, protocol))
662 			continue;
663 		if (term->bTerminalID == terminal_id)
664 			return term;
665 	}
666 
667 	return NULL;
668 }
669 
670 static struct audioformat *
671 audio_format_alloc_init(struct snd_usb_audio *chip,
672 		       struct usb_host_interface *alts,
673 		       int protocol, int iface_no, int altset_idx,
674 		       int altno, int num_channels, int clock)
675 {
676 	struct audioformat *fp;
677 
678 	fp = kzalloc(sizeof(*fp), GFP_KERNEL);
679 	if (!fp)
680 		return NULL;
681 
682 	fp->iface = iface_no;
683 	fp->altsetting = altno;
684 	fp->altset_idx = altset_idx;
685 	fp->endpoint = get_endpoint(alts, 0)->bEndpointAddress;
686 	fp->ep_attr = get_endpoint(alts, 0)->bmAttributes;
687 	fp->datainterval = snd_usb_parse_datainterval(chip, alts);
688 	fp->protocol = protocol;
689 	fp->maxpacksize = le16_to_cpu(get_endpoint(alts, 0)->wMaxPacketSize);
690 	fp->channels = num_channels;
691 	if (snd_usb_get_speed(chip->dev) == USB_SPEED_HIGH)
692 		fp->maxpacksize = (((fp->maxpacksize >> 11) & 3) + 1)
693 				* (fp->maxpacksize & 0x7ff);
694 	fp->clock = clock;
695 	INIT_LIST_HEAD(&fp->list);
696 
697 	return fp;
698 }
699 
700 static struct audioformat *
701 snd_usb_get_audioformat_uac12(struct snd_usb_audio *chip,
702 			      struct usb_host_interface *alts,
703 			      int protocol, int iface_no, int altset_idx,
704 			      int altno, int stream, int bm_quirk)
705 {
706 	struct usb_device *dev = chip->dev;
707 	struct uac_format_type_i_continuous_descriptor *fmt;
708 	unsigned int num_channels = 0, chconfig = 0;
709 	struct audioformat *fp;
710 	int clock = 0;
711 	u64 format;
712 
713 	/* get audio formats */
714 	if (protocol == UAC_VERSION_1) {
715 		struct uac1_as_header_descriptor *as =
716 			snd_usb_find_csint_desc(alts->extra, alts->extralen,
717 						NULL, UAC_AS_GENERAL);
718 		struct uac_input_terminal_descriptor *iterm;
719 
720 		if (!as) {
721 			dev_err(&dev->dev,
722 				"%u:%d : UAC_AS_GENERAL descriptor not found\n",
723 				iface_no, altno);
724 			return NULL;
725 		}
726 
727 		if (as->bLength < sizeof(*as)) {
728 			dev_err(&dev->dev,
729 				"%u:%d : invalid UAC_AS_GENERAL desc\n",
730 				iface_no, altno);
731 			return NULL;
732 		}
733 
734 		format = le16_to_cpu(as->wFormatTag); /* remember the format value */
735 
736 		iterm = snd_usb_find_input_terminal_descriptor(chip->ctrl_intf,
737 							       as->bTerminalLink,
738 							       protocol);
739 		if (iterm) {
740 			num_channels = iterm->bNrChannels;
741 			chconfig = le16_to_cpu(iterm->wChannelConfig);
742 		}
743 	} else { /* UAC_VERSION_2 */
744 		struct uac2_input_terminal_descriptor *input_term;
745 		struct uac2_output_terminal_descriptor *output_term;
746 		struct uac2_as_header_descriptor *as =
747 			snd_usb_find_csint_desc(alts->extra, alts->extralen,
748 						NULL, UAC_AS_GENERAL);
749 
750 		if (!as) {
751 			dev_err(&dev->dev,
752 				"%u:%d : UAC_AS_GENERAL descriptor not found\n",
753 				iface_no, altno);
754 			return NULL;
755 		}
756 
757 		if (as->bLength < sizeof(*as)) {
758 			dev_err(&dev->dev,
759 				"%u:%d : invalid UAC_AS_GENERAL desc\n",
760 				iface_no, altno);
761 			return NULL;
762 		}
763 
764 		num_channels = as->bNrChannels;
765 		format = le32_to_cpu(as->bmFormats);
766 		chconfig = le32_to_cpu(as->bmChannelConfig);
767 
768 		/*
769 		 * lookup the terminal associated to this interface
770 		 * to extract the clock
771 		 */
772 		input_term = snd_usb_find_input_terminal_descriptor(chip->ctrl_intf,
773 								    as->bTerminalLink,
774 								    protocol);
775 		if (input_term) {
776 			clock = input_term->bCSourceID;
777 			if (!chconfig && (num_channels == input_term->bNrChannels))
778 				chconfig = le32_to_cpu(input_term->bmChannelConfig);
779 			goto found_clock;
780 		}
781 
782 		output_term = snd_usb_find_output_terminal_descriptor(chip->ctrl_intf,
783 								      as->bTerminalLink,
784 								      protocol);
785 		if (output_term) {
786 			clock = output_term->bCSourceID;
787 			goto found_clock;
788 		}
789 
790 		dev_err(&dev->dev,
791 			"%u:%d : bogus bTerminalLink %d\n",
792 			iface_no, altno, as->bTerminalLink);
793 		return NULL;
794 	}
795 
796 found_clock:
797 	/* get format type */
798 	fmt = snd_usb_find_csint_desc(alts->extra, alts->extralen,
799 				      NULL, UAC_FORMAT_TYPE);
800 	if (!fmt) {
801 		dev_err(&dev->dev,
802 			"%u:%d : no UAC_FORMAT_TYPE desc\n",
803 			iface_no, altno);
804 		return NULL;
805 	}
806 	if (((protocol == UAC_VERSION_1) && (fmt->bLength < 8))
807 			|| ((protocol == UAC_VERSION_2) &&
808 					(fmt->bLength < 6))) {
809 		dev_err(&dev->dev,
810 			"%u:%d : invalid UAC_FORMAT_TYPE desc\n",
811 			iface_no, altno);
812 		return NULL;
813 	}
814 
815 	/*
816 	 * Blue Microphones workaround: The last altsetting is
817 	 * identical with the previous one, except for a larger
818 	 * packet size, but is actually a mislabeled two-channel
819 	 * setting; ignore it.
820 	 *
821 	 * Part 2: analyze quirk flag and format
822 	 */
823 	if (bm_quirk && fmt->bNrChannels == 1 && fmt->bSubframeSize == 2)
824 		return NULL;
825 
826 	fp = audio_format_alloc_init(chip, alts, protocol, iface_no,
827 				     altset_idx, altno, num_channels, clock);
828 	if (!fp)
829 		return ERR_PTR(-ENOMEM);
830 
831 	fp->attributes = parse_uac_endpoint_attributes(chip, alts, protocol,
832 						       iface_no);
833 
834 	/* some quirks for attributes here */
835 	snd_usb_audioformat_attributes_quirk(chip, fp, stream);
836 
837 	/* ok, let's parse further... */
838 	if (snd_usb_parse_audio_format(chip, fp, format,
839 					fmt, stream) < 0) {
840 		audioformat_free(fp);
841 		return NULL;
842 	}
843 
844 	/* Create chmap */
845 	if (fp->channels != num_channels)
846 		chconfig = 0;
847 
848 	fp->chmap = convert_chmap(fp->channels, chconfig, protocol);
849 
850 	return fp;
851 }
852 
853 static struct audioformat *
854 snd_usb_get_audioformat_uac3(struct snd_usb_audio *chip,
855 			     struct usb_host_interface *alts,
856 			     struct snd_usb_power_domain **pd_out,
857 			     int iface_no, int altset_idx,
858 			     int altno, int stream)
859 {
860 	struct usb_device *dev = chip->dev;
861 	struct uac3_input_terminal_descriptor *input_term;
862 	struct uac3_output_terminal_descriptor *output_term;
863 	struct uac3_cluster_header_descriptor *cluster;
864 	struct uac3_as_header_descriptor *as = NULL;
865 	struct uac3_hc_descriptor_header hc_header;
866 	struct snd_pcm_chmap_elem *chmap;
867 	struct snd_usb_power_domain *pd;
868 	unsigned char badd_profile;
869 	u64 badd_formats = 0;
870 	unsigned int num_channels;
871 	struct audioformat *fp;
872 	u16 cluster_id, wLength;
873 	int clock = 0;
874 	int err;
875 
876 	badd_profile = chip->badd_profile;
877 
878 	if (badd_profile >= UAC3_FUNCTION_SUBCLASS_GENERIC_IO) {
879 		unsigned int maxpacksize =
880 			le16_to_cpu(get_endpoint(alts, 0)->wMaxPacketSize);
881 
882 		switch (maxpacksize) {
883 		default:
884 			dev_err(&dev->dev,
885 				"%u:%d : incorrect wMaxPacketSize for BADD profile\n",
886 				iface_no, altno);
887 			return NULL;
888 		case UAC3_BADD_EP_MAXPSIZE_SYNC_MONO_16:
889 		case UAC3_BADD_EP_MAXPSIZE_ASYNC_MONO_16:
890 			badd_formats = SNDRV_PCM_FMTBIT_S16_LE;
891 			num_channels = 1;
892 			break;
893 		case UAC3_BADD_EP_MAXPSIZE_SYNC_MONO_24:
894 		case UAC3_BADD_EP_MAXPSIZE_ASYNC_MONO_24:
895 			badd_formats = SNDRV_PCM_FMTBIT_S24_3LE;
896 			num_channels = 1;
897 			break;
898 		case UAC3_BADD_EP_MAXPSIZE_SYNC_STEREO_16:
899 		case UAC3_BADD_EP_MAXPSIZE_ASYNC_STEREO_16:
900 			badd_formats = SNDRV_PCM_FMTBIT_S16_LE;
901 			num_channels = 2;
902 			break;
903 		case UAC3_BADD_EP_MAXPSIZE_SYNC_STEREO_24:
904 		case UAC3_BADD_EP_MAXPSIZE_ASYNC_STEREO_24:
905 			badd_formats = SNDRV_PCM_FMTBIT_S24_3LE;
906 			num_channels = 2;
907 			break;
908 		}
909 
910 		chmap = kzalloc(sizeof(*chmap), GFP_KERNEL);
911 		if (!chmap)
912 			return ERR_PTR(-ENOMEM);
913 
914 		if (num_channels == 1) {
915 			chmap->map[0] = SNDRV_CHMAP_MONO;
916 		} else {
917 			chmap->map[0] = SNDRV_CHMAP_FL;
918 			chmap->map[1] = SNDRV_CHMAP_FR;
919 		}
920 
921 		chmap->channels = num_channels;
922 		clock = UAC3_BADD_CS_ID9;
923 		goto found_clock;
924 	}
925 
926 	as = snd_usb_find_csint_desc(alts->extra, alts->extralen,
927 				     NULL, UAC_AS_GENERAL);
928 	if (!as) {
929 		dev_err(&dev->dev,
930 			"%u:%d : UAC_AS_GENERAL descriptor not found\n",
931 			iface_no, altno);
932 		return NULL;
933 	}
934 
935 	if (as->bLength < sizeof(*as)) {
936 		dev_err(&dev->dev,
937 			"%u:%d : invalid UAC_AS_GENERAL desc\n",
938 			iface_no, altno);
939 		return NULL;
940 	}
941 
942 	cluster_id = le16_to_cpu(as->wClusterDescrID);
943 	if (!cluster_id) {
944 		dev_err(&dev->dev,
945 			"%u:%d : no cluster descriptor\n",
946 			iface_no, altno);
947 		return NULL;
948 	}
949 
950 	/*
951 	 * Get number of channels and channel map through
952 	 * High Capability Cluster Descriptor
953 	 *
954 	 * First step: get High Capability header and
955 	 * read size of Cluster Descriptor
956 	 */
957 	err = snd_usb_ctl_msg(chip->dev,
958 			usb_rcvctrlpipe(chip->dev, 0),
959 			UAC3_CS_REQ_HIGH_CAPABILITY_DESCRIPTOR,
960 			USB_RECIP_INTERFACE | USB_TYPE_CLASS | USB_DIR_IN,
961 			cluster_id,
962 			snd_usb_ctrl_intf(chip),
963 			&hc_header, sizeof(hc_header));
964 	if (err < 0)
965 		return ERR_PTR(err);
966 	else if (err != sizeof(hc_header)) {
967 		dev_err(&dev->dev,
968 			"%u:%d : can't get High Capability descriptor\n",
969 			iface_no, altno);
970 		return ERR_PTR(-EIO);
971 	}
972 
973 	/*
974 	 * Second step: allocate needed amount of memory
975 	 * and request Cluster Descriptor
976 	 */
977 	wLength = le16_to_cpu(hc_header.wLength);
978 	cluster = kzalloc(wLength, GFP_KERNEL);
979 	if (!cluster)
980 		return ERR_PTR(-ENOMEM);
981 	err = snd_usb_ctl_msg(chip->dev,
982 			usb_rcvctrlpipe(chip->dev, 0),
983 			UAC3_CS_REQ_HIGH_CAPABILITY_DESCRIPTOR,
984 			USB_RECIP_INTERFACE | USB_TYPE_CLASS | USB_DIR_IN,
985 			cluster_id,
986 			snd_usb_ctrl_intf(chip),
987 			cluster, wLength);
988 	if (err < 0) {
989 		kfree(cluster);
990 		return ERR_PTR(err);
991 	} else if (err != wLength) {
992 		dev_err(&dev->dev,
993 			"%u:%d : can't get Cluster Descriptor\n",
994 			iface_no, altno);
995 		kfree(cluster);
996 		return ERR_PTR(-EIO);
997 	}
998 
999 	num_channels = cluster->bNrChannels;
1000 	chmap = convert_chmap_v3(cluster);
1001 	kfree(cluster);
1002 
1003 	/*
1004 	 * lookup the terminal associated to this interface
1005 	 * to extract the clock
1006 	 */
1007 	input_term = snd_usb_find_input_terminal_descriptor(chip->ctrl_intf,
1008 							    as->bTerminalLink,
1009 							    UAC_VERSION_3);
1010 	if (input_term) {
1011 		clock = input_term->bCSourceID;
1012 		goto found_clock;
1013 	}
1014 
1015 	output_term = snd_usb_find_output_terminal_descriptor(chip->ctrl_intf,
1016 							      as->bTerminalLink,
1017 							      UAC_VERSION_3);
1018 	if (output_term) {
1019 		clock = output_term->bCSourceID;
1020 		goto found_clock;
1021 	}
1022 
1023 	dev_err(&dev->dev, "%u:%d : bogus bTerminalLink %d\n",
1024 			iface_no, altno, as->bTerminalLink);
1025 	kfree(chmap);
1026 	return NULL;
1027 
1028 found_clock:
1029 	fp = audio_format_alloc_init(chip, alts, UAC_VERSION_3, iface_no,
1030 				     altset_idx, altno, num_channels, clock);
1031 	if (!fp) {
1032 		kfree(chmap);
1033 		return ERR_PTR(-ENOMEM);
1034 	}
1035 
1036 	fp->chmap = chmap;
1037 
1038 	if (badd_profile >= UAC3_FUNCTION_SUBCLASS_GENERIC_IO) {
1039 		fp->attributes = 0; /* No attributes */
1040 
1041 		fp->fmt_type = UAC_FORMAT_TYPE_I;
1042 		fp->formats = badd_formats;
1043 
1044 		fp->nr_rates = 0;	/* SNDRV_PCM_RATE_CONTINUOUS */
1045 		fp->rate_min = UAC3_BADD_SAMPLING_RATE;
1046 		fp->rate_max = UAC3_BADD_SAMPLING_RATE;
1047 		fp->rates = SNDRV_PCM_RATE_CONTINUOUS;
1048 
1049 		pd = kzalloc(sizeof(*pd), GFP_KERNEL);
1050 		if (!pd) {
1051 			audioformat_free(fp);
1052 			return NULL;
1053 		}
1054 		pd->pd_id = (stream == SNDRV_PCM_STREAM_PLAYBACK) ?
1055 					UAC3_BADD_PD_ID10 : UAC3_BADD_PD_ID11;
1056 		pd->pd_d1d0_rec = UAC3_BADD_PD_RECOVER_D1D0;
1057 		pd->pd_d2d0_rec = UAC3_BADD_PD_RECOVER_D2D0;
1058 
1059 	} else {
1060 		fp->attributes = parse_uac_endpoint_attributes(chip, alts,
1061 							       UAC_VERSION_3,
1062 							       iface_no);
1063 
1064 		pd = snd_usb_find_power_domain(chip->ctrl_intf,
1065 					       as->bTerminalLink);
1066 
1067 		/* ok, let's parse further... */
1068 		if (snd_usb_parse_audio_format_v3(chip, fp, as, stream) < 0) {
1069 			kfree(pd);
1070 			audioformat_free(fp);
1071 			return NULL;
1072 		}
1073 	}
1074 
1075 	if (pd)
1076 		*pd_out = pd;
1077 
1078 	return fp;
1079 }
1080 
1081 static int __snd_usb_parse_audio_interface(struct snd_usb_audio *chip,
1082 					   int iface_no,
1083 					   bool *has_non_pcm, bool non_pcm)
1084 {
1085 	struct usb_device *dev;
1086 	struct usb_interface *iface;
1087 	struct usb_host_interface *alts;
1088 	struct usb_interface_descriptor *altsd;
1089 	int i, altno, err, stream;
1090 	struct audioformat *fp = NULL;
1091 	struct snd_usb_power_domain *pd = NULL;
1092 	int num, protocol;
1093 
1094 	dev = chip->dev;
1095 
1096 	/* parse the interface's altsettings */
1097 	iface = usb_ifnum_to_if(dev, iface_no);
1098 
1099 	num = iface->num_altsetting;
1100 
1101 	/*
1102 	 * Dallas DS4201 workaround: It presents 5 altsettings, but the last
1103 	 * one misses syncpipe, and does not produce any sound.
1104 	 */
1105 	if (chip->usb_id == USB_ID(0x04fa, 0x4201))
1106 		num = 4;
1107 
1108 	for (i = 0; i < num; i++) {
1109 		alts = &iface->altsetting[i];
1110 		altsd = get_iface_desc(alts);
1111 		protocol = altsd->bInterfaceProtocol;
1112 		/* skip invalid one */
1113 		if (((altsd->bInterfaceClass != USB_CLASS_AUDIO ||
1114 		      (altsd->bInterfaceSubClass != USB_SUBCLASS_AUDIOSTREAMING &&
1115 		       altsd->bInterfaceSubClass != USB_SUBCLASS_VENDOR_SPEC)) &&
1116 		     altsd->bInterfaceClass != USB_CLASS_VENDOR_SPEC) ||
1117 		    altsd->bNumEndpoints < 1 ||
1118 		    le16_to_cpu(get_endpoint(alts, 0)->wMaxPacketSize) == 0)
1119 			continue;
1120 		/* must be isochronous */
1121 		if ((get_endpoint(alts, 0)->bmAttributes & USB_ENDPOINT_XFERTYPE_MASK) !=
1122 		    USB_ENDPOINT_XFER_ISOC)
1123 			continue;
1124 		/* check direction */
1125 		stream = (get_endpoint(alts, 0)->bEndpointAddress & USB_DIR_IN) ?
1126 			SNDRV_PCM_STREAM_CAPTURE : SNDRV_PCM_STREAM_PLAYBACK;
1127 		altno = altsd->bAlternateSetting;
1128 
1129 		if (snd_usb_apply_interface_quirk(chip, iface_no, altno))
1130 			continue;
1131 
1132 		/*
1133 		 * Roland audio streaming interfaces are marked with protocols
1134 		 * 0/1/2, but are UAC 1 compatible.
1135 		 */
1136 		if (USB_ID_VENDOR(chip->usb_id) == 0x0582 &&
1137 		    altsd->bInterfaceClass == USB_CLASS_VENDOR_SPEC &&
1138 		    protocol <= 2)
1139 			protocol = UAC_VERSION_1;
1140 
1141 		switch (protocol) {
1142 		default:
1143 			dev_dbg(&dev->dev, "%u:%d: unknown interface protocol %#02x, assuming v1\n",
1144 				iface_no, altno, protocol);
1145 			protocol = UAC_VERSION_1;
1146 			/* fall through */
1147 		case UAC_VERSION_1:
1148 			/* fall through */
1149 		case UAC_VERSION_2: {
1150 			int bm_quirk = 0;
1151 
1152 			/*
1153 			 * Blue Microphones workaround: The last altsetting is
1154 			 * identical with the previous one, except for a larger
1155 			 * packet size, but is actually a mislabeled two-channel
1156 			 * setting; ignore it.
1157 			 *
1158 			 * Part 1: prepare quirk flag
1159 			 */
1160 			if (altno == 2 && num == 3 &&
1161 			    fp && fp->altsetting == 1 && fp->channels == 1 &&
1162 			    fp->formats == SNDRV_PCM_FMTBIT_S16_LE &&
1163 			    protocol == UAC_VERSION_1 &&
1164 			    le16_to_cpu(get_endpoint(alts, 0)->wMaxPacketSize) ==
1165 							fp->maxpacksize * 2)
1166 				bm_quirk = 1;
1167 
1168 			fp = snd_usb_get_audioformat_uac12(chip, alts, protocol,
1169 							   iface_no, i, altno,
1170 							   stream, bm_quirk);
1171 			break;
1172 		}
1173 		case UAC_VERSION_3:
1174 			fp = snd_usb_get_audioformat_uac3(chip, alts, &pd,
1175 						iface_no, i, altno, stream);
1176 			break;
1177 		}
1178 
1179 		if (!fp)
1180 			continue;
1181 		else if (IS_ERR(fp))
1182 			return PTR_ERR(fp);
1183 
1184 		if (fp->fmt_type != UAC_FORMAT_TYPE_I)
1185 			*has_non_pcm = true;
1186 		if ((fp->fmt_type == UAC_FORMAT_TYPE_I) == non_pcm) {
1187 			audioformat_free(fp);
1188 			kfree(pd);
1189 			fp = NULL;
1190 			pd = NULL;
1191 			continue;
1192 		}
1193 
1194 		dev_dbg(&dev->dev, "%u:%d: add audio endpoint %#x\n", iface_no, altno, fp->endpoint);
1195 		if (protocol == UAC_VERSION_3)
1196 			err = snd_usb_add_audio_stream_v3(chip, stream, fp, pd);
1197 		else
1198 			err = snd_usb_add_audio_stream(chip, stream, fp);
1199 
1200 		if (err < 0) {
1201 			audioformat_free(fp);
1202 			kfree(pd);
1203 			return err;
1204 		}
1205 		/* try to set the interface... */
1206 		usb_set_interface(chip->dev, iface_no, altno);
1207 		snd_usb_init_pitch(chip, iface_no, alts, fp);
1208 		snd_usb_init_sample_rate(chip, iface_no, alts, fp, fp->rate_max);
1209 	}
1210 	return 0;
1211 }
1212 
1213 int snd_usb_parse_audio_interface(struct snd_usb_audio *chip, int iface_no)
1214 {
1215 	int err;
1216 	bool has_non_pcm = false;
1217 
1218 	/* parse PCM formats */
1219 	err = __snd_usb_parse_audio_interface(chip, iface_no, &has_non_pcm, false);
1220 	if (err < 0)
1221 		return err;
1222 
1223 	if (has_non_pcm) {
1224 		/* parse non-PCM formats */
1225 		err = __snd_usb_parse_audio_interface(chip, iface_no, &has_non_pcm, true);
1226 		if (err < 0)
1227 			return err;
1228 	}
1229 
1230 	return 0;
1231 }
1232 
1233