xref: /linux/sound/usb/stream.c (revision 962fad301c33dec69324dc2d9320fd84a119a24c)
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 	subs->stream_offset_adj = 0;
98 
99 	snd_usb_set_pcm_ops(as->pcm, stream);
100 
101 	list_add_tail(&fp->list, &subs->fmt_list);
102 	subs->formats |= fp->formats;
103 	subs->num_formats++;
104 	subs->fmt_type = fp->fmt_type;
105 	subs->ep_num = fp->endpoint;
106 	if (fp->channels > subs->channels_max)
107 		subs->channels_max = fp->channels;
108 
109 	if (pd) {
110 		subs->str_pd = pd;
111 		/* Initialize Power Domain to idle status D1 */
112 		snd_usb_power_domain_set(subs->stream->chip, pd,
113 					 UAC3_PD_STATE_D1);
114 	}
115 
116 	snd_usb_preallocate_buffer(subs);
117 }
118 
119 /* kctl callbacks for usb-audio channel maps */
120 static int usb_chmap_ctl_info(struct snd_kcontrol *kcontrol,
121 			      struct snd_ctl_elem_info *uinfo)
122 {
123 	struct snd_pcm_chmap *info = snd_kcontrol_chip(kcontrol);
124 	struct snd_usb_substream *subs = info->private_data;
125 
126 	uinfo->type = SNDRV_CTL_ELEM_TYPE_INTEGER;
127 	uinfo->count = subs->channels_max;
128 	uinfo->value.integer.min = 0;
129 	uinfo->value.integer.max = SNDRV_CHMAP_LAST;
130 	return 0;
131 }
132 
133 /* check whether a duplicated entry exists in the audiofmt list */
134 static bool have_dup_chmap(struct snd_usb_substream *subs,
135 			   struct audioformat *fp)
136 {
137 	struct audioformat *prev = fp;
138 
139 	list_for_each_entry_continue_reverse(prev, &subs->fmt_list, list) {
140 		if (prev->chmap &&
141 		    !memcmp(prev->chmap, fp->chmap, sizeof(*fp->chmap)))
142 			return true;
143 	}
144 	return false;
145 }
146 
147 static int usb_chmap_ctl_tlv(struct snd_kcontrol *kcontrol, int op_flag,
148 			     unsigned int size, unsigned int __user *tlv)
149 {
150 	struct snd_pcm_chmap *info = snd_kcontrol_chip(kcontrol);
151 	struct snd_usb_substream *subs = info->private_data;
152 	struct audioformat *fp;
153 	unsigned int __user *dst;
154 	int count = 0;
155 
156 	if (size < 8)
157 		return -ENOMEM;
158 	if (put_user(SNDRV_CTL_TLVT_CONTAINER, tlv))
159 		return -EFAULT;
160 	size -= 8;
161 	dst = tlv + 2;
162 	list_for_each_entry(fp, &subs->fmt_list, list) {
163 		int i, ch_bytes;
164 
165 		if (!fp->chmap)
166 			continue;
167 		if (have_dup_chmap(subs, fp))
168 			continue;
169 		/* copy the entry */
170 		ch_bytes = fp->chmap->channels * 4;
171 		if (size < 8 + ch_bytes)
172 			return -ENOMEM;
173 		if (put_user(SNDRV_CTL_TLVT_CHMAP_FIXED, dst) ||
174 		    put_user(ch_bytes, dst + 1))
175 			return -EFAULT;
176 		dst += 2;
177 		for (i = 0; i < fp->chmap->channels; i++, dst++) {
178 			if (put_user(fp->chmap->map[i], dst))
179 				return -EFAULT;
180 		}
181 
182 		count += 8 + ch_bytes;
183 		size -= 8 + ch_bytes;
184 	}
185 	if (put_user(count, tlv + 1))
186 		return -EFAULT;
187 	return 0;
188 }
189 
190 static int usb_chmap_ctl_get(struct snd_kcontrol *kcontrol,
191 			     struct snd_ctl_elem_value *ucontrol)
192 {
193 	struct snd_pcm_chmap *info = snd_kcontrol_chip(kcontrol);
194 	struct snd_usb_substream *subs = info->private_data;
195 	struct snd_pcm_chmap_elem *chmap = NULL;
196 	int i;
197 
198 	memset(ucontrol->value.integer.value, 0,
199 	       sizeof(ucontrol->value.integer.value));
200 	if (subs->cur_audiofmt)
201 		chmap = subs->cur_audiofmt->chmap;
202 	if (chmap) {
203 		for (i = 0; i < chmap->channels; i++)
204 			ucontrol->value.integer.value[i] = chmap->map[i];
205 	}
206 	return 0;
207 }
208 
209 /* create a chmap kctl assigned to the given USB substream */
210 static int add_chmap(struct snd_pcm *pcm, int stream,
211 		     struct snd_usb_substream *subs)
212 {
213 	struct audioformat *fp;
214 	struct snd_pcm_chmap *chmap;
215 	struct snd_kcontrol *kctl;
216 	int err;
217 
218 	list_for_each_entry(fp, &subs->fmt_list, list)
219 		if (fp->chmap)
220 			goto ok;
221 	/* no chmap is found */
222 	return 0;
223 
224  ok:
225 	err = snd_pcm_add_chmap_ctls(pcm, stream, NULL, 0, 0, &chmap);
226 	if (err < 0)
227 		return err;
228 
229 	/* override handlers */
230 	chmap->private_data = subs;
231 	kctl = chmap->kctl;
232 	kctl->info = usb_chmap_ctl_info;
233 	kctl->get = usb_chmap_ctl_get;
234 	kctl->tlv.c = usb_chmap_ctl_tlv;
235 
236 	return 0;
237 }
238 
239 /* convert from USB ChannelConfig bits to ALSA chmap element */
240 static struct snd_pcm_chmap_elem *convert_chmap(int channels, unsigned int bits,
241 						int protocol)
242 {
243 	static const unsigned int uac1_maps[] = {
244 		SNDRV_CHMAP_FL,		/* left front */
245 		SNDRV_CHMAP_FR,		/* right front */
246 		SNDRV_CHMAP_FC,		/* center front */
247 		SNDRV_CHMAP_LFE,	/* LFE */
248 		SNDRV_CHMAP_SL,		/* left surround */
249 		SNDRV_CHMAP_SR,		/* right surround */
250 		SNDRV_CHMAP_FLC,	/* left of center */
251 		SNDRV_CHMAP_FRC,	/* right of center */
252 		SNDRV_CHMAP_RC,		/* surround */
253 		SNDRV_CHMAP_SL,		/* side left */
254 		SNDRV_CHMAP_SR,		/* side right */
255 		SNDRV_CHMAP_TC,		/* top */
256 		0 /* terminator */
257 	};
258 	static const unsigned int uac2_maps[] = {
259 		SNDRV_CHMAP_FL,		/* front left */
260 		SNDRV_CHMAP_FR,		/* front right */
261 		SNDRV_CHMAP_FC,		/* front center */
262 		SNDRV_CHMAP_LFE,	/* LFE */
263 		SNDRV_CHMAP_RL,		/* back left */
264 		SNDRV_CHMAP_RR,		/* back right */
265 		SNDRV_CHMAP_FLC,	/* front left of center */
266 		SNDRV_CHMAP_FRC,	/* front right of center */
267 		SNDRV_CHMAP_RC,		/* back center */
268 		SNDRV_CHMAP_SL,		/* side left */
269 		SNDRV_CHMAP_SR,		/* side right */
270 		SNDRV_CHMAP_TC,		/* top center */
271 		SNDRV_CHMAP_TFL,	/* top front left */
272 		SNDRV_CHMAP_TFC,	/* top front center */
273 		SNDRV_CHMAP_TFR,	/* top front right */
274 		SNDRV_CHMAP_TRL,	/* top back left */
275 		SNDRV_CHMAP_TRC,	/* top back center */
276 		SNDRV_CHMAP_TRR,	/* top back right */
277 		SNDRV_CHMAP_TFLC,	/* top front left of center */
278 		SNDRV_CHMAP_TFRC,	/* top front right of center */
279 		SNDRV_CHMAP_LLFE,	/* left LFE */
280 		SNDRV_CHMAP_RLFE,	/* right LFE */
281 		SNDRV_CHMAP_TSL,	/* top side left */
282 		SNDRV_CHMAP_TSR,	/* top side right */
283 		SNDRV_CHMAP_BC,		/* bottom center */
284 		SNDRV_CHMAP_RLC,	/* back left of center */
285 		SNDRV_CHMAP_RRC,	/* back right of center */
286 		0 /* terminator */
287 	};
288 	struct snd_pcm_chmap_elem *chmap;
289 	const unsigned int *maps;
290 	int c;
291 
292 	if (channels > ARRAY_SIZE(chmap->map))
293 		return NULL;
294 
295 	chmap = kzalloc(sizeof(*chmap), GFP_KERNEL);
296 	if (!chmap)
297 		return NULL;
298 
299 	maps = protocol == UAC_VERSION_2 ? uac2_maps : uac1_maps;
300 	chmap->channels = channels;
301 	c = 0;
302 
303 	if (bits) {
304 		for (; bits && *maps; maps++, bits >>= 1)
305 			if (bits & 1)
306 				chmap->map[c++] = *maps;
307 	} else {
308 		/* If we're missing wChannelConfig, then guess something
309 		    to make sure the channel map is not skipped entirely */
310 		if (channels == 1)
311 			chmap->map[c++] = SNDRV_CHMAP_MONO;
312 		else
313 			for (; c < channels && *maps; maps++)
314 				chmap->map[c++] = *maps;
315 	}
316 
317 	for (; c < channels; c++)
318 		chmap->map[c] = SNDRV_CHMAP_UNKNOWN;
319 
320 	return chmap;
321 }
322 
323 /* UAC3 device stores channels information in Cluster Descriptors */
324 static struct
325 snd_pcm_chmap_elem *convert_chmap_v3(struct uac3_cluster_header_descriptor
326 								*cluster)
327 {
328 	unsigned int channels = cluster->bNrChannels;
329 	struct snd_pcm_chmap_elem *chmap;
330 	void *p = cluster;
331 	int len, c;
332 
333 	if (channels > ARRAY_SIZE(chmap->map))
334 		return NULL;
335 
336 	chmap = kzalloc(sizeof(*chmap), GFP_KERNEL);
337 	if (!chmap)
338 		return NULL;
339 
340 	len = le16_to_cpu(cluster->wLength);
341 	c = 0;
342 	p += sizeof(struct uac3_cluster_header_descriptor);
343 
344 	while (((p - (void *)cluster) < len) && (c < channels)) {
345 		struct uac3_cluster_segment_descriptor *cs_desc = p;
346 		u16 cs_len;
347 		u8 cs_type;
348 
349 		cs_len = le16_to_cpu(cs_desc->wLength);
350 		cs_type = cs_desc->bSegmentType;
351 
352 		if (cs_type == UAC3_CHANNEL_INFORMATION) {
353 			struct uac3_cluster_information_segment_descriptor *is = p;
354 			unsigned char map;
355 
356 			/*
357 			 * TODO: this conversion is not complete, update it
358 			 * after adding UAC3 values to asound.h
359 			 */
360 			switch (is->bChRelationship) {
361 			case UAC3_CH_MONO:
362 				map = SNDRV_CHMAP_MONO;
363 				break;
364 			case UAC3_CH_LEFT:
365 			case UAC3_CH_FRONT_LEFT:
366 			case UAC3_CH_HEADPHONE_LEFT:
367 				map = SNDRV_CHMAP_FL;
368 				break;
369 			case UAC3_CH_RIGHT:
370 			case UAC3_CH_FRONT_RIGHT:
371 			case UAC3_CH_HEADPHONE_RIGHT:
372 				map = SNDRV_CHMAP_FR;
373 				break;
374 			case UAC3_CH_FRONT_CENTER:
375 				map = SNDRV_CHMAP_FC;
376 				break;
377 			case UAC3_CH_FRONT_LEFT_OF_CENTER:
378 				map = SNDRV_CHMAP_FLC;
379 				break;
380 			case UAC3_CH_FRONT_RIGHT_OF_CENTER:
381 				map = SNDRV_CHMAP_FRC;
382 				break;
383 			case UAC3_CH_SIDE_LEFT:
384 				map = SNDRV_CHMAP_SL;
385 				break;
386 			case UAC3_CH_SIDE_RIGHT:
387 				map = SNDRV_CHMAP_SR;
388 				break;
389 			case UAC3_CH_BACK_LEFT:
390 				map = SNDRV_CHMAP_RL;
391 				break;
392 			case UAC3_CH_BACK_RIGHT:
393 				map = SNDRV_CHMAP_RR;
394 				break;
395 			case UAC3_CH_BACK_CENTER:
396 				map = SNDRV_CHMAP_RC;
397 				break;
398 			case UAC3_CH_BACK_LEFT_OF_CENTER:
399 				map = SNDRV_CHMAP_RLC;
400 				break;
401 			case UAC3_CH_BACK_RIGHT_OF_CENTER:
402 				map = SNDRV_CHMAP_RRC;
403 				break;
404 			case UAC3_CH_TOP_CENTER:
405 				map = SNDRV_CHMAP_TC;
406 				break;
407 			case UAC3_CH_TOP_FRONT_LEFT:
408 				map = SNDRV_CHMAP_TFL;
409 				break;
410 			case UAC3_CH_TOP_FRONT_RIGHT:
411 				map = SNDRV_CHMAP_TFR;
412 				break;
413 			case UAC3_CH_TOP_FRONT_CENTER:
414 				map = SNDRV_CHMAP_TFC;
415 				break;
416 			case UAC3_CH_TOP_FRONT_LOC:
417 				map = SNDRV_CHMAP_TFLC;
418 				break;
419 			case UAC3_CH_TOP_FRONT_ROC:
420 				map = SNDRV_CHMAP_TFRC;
421 				break;
422 			case UAC3_CH_TOP_SIDE_LEFT:
423 				map = SNDRV_CHMAP_TSL;
424 				break;
425 			case UAC3_CH_TOP_SIDE_RIGHT:
426 				map = SNDRV_CHMAP_TSR;
427 				break;
428 			case UAC3_CH_TOP_BACK_LEFT:
429 				map = SNDRV_CHMAP_TRL;
430 				break;
431 			case UAC3_CH_TOP_BACK_RIGHT:
432 				map = SNDRV_CHMAP_TRR;
433 				break;
434 			case UAC3_CH_TOP_BACK_CENTER:
435 				map = SNDRV_CHMAP_TRC;
436 				break;
437 			case UAC3_CH_BOTTOM_CENTER:
438 				map = SNDRV_CHMAP_BC;
439 				break;
440 			case UAC3_CH_LOW_FREQUENCY_EFFECTS:
441 				map = SNDRV_CHMAP_LFE;
442 				break;
443 			case UAC3_CH_LFE_LEFT:
444 				map = SNDRV_CHMAP_LLFE;
445 				break;
446 			case UAC3_CH_LFE_RIGHT:
447 				map = SNDRV_CHMAP_RLFE;
448 				break;
449 			case UAC3_CH_RELATIONSHIP_UNDEFINED:
450 			default:
451 				map = SNDRV_CHMAP_UNKNOWN;
452 				break;
453 			}
454 			chmap->map[c++] = map;
455 		}
456 		p += cs_len;
457 	}
458 
459 	if (channels < c)
460 		pr_err("%s: channel number mismatch\n", __func__);
461 
462 	chmap->channels = channels;
463 
464 	for (; c < channels; c++)
465 		chmap->map[c] = SNDRV_CHMAP_UNKNOWN;
466 
467 	return chmap;
468 }
469 
470 /*
471  * add this endpoint to the chip instance.
472  * if a stream with the same endpoint already exists, append to it.
473  * if not, create a new pcm stream. note, fp is added to the substream
474  * fmt_list and will be freed on the chip instance release. do not free
475  * fp or do remove it from the substream fmt_list to avoid double-free.
476  */
477 static int __snd_usb_add_audio_stream(struct snd_usb_audio *chip,
478 				      int stream,
479 				      struct audioformat *fp,
480 				      struct snd_usb_power_domain *pd)
481 
482 {
483 	struct snd_usb_stream *as;
484 	struct snd_usb_substream *subs;
485 	struct snd_pcm *pcm;
486 	int err;
487 
488 	list_for_each_entry(as, &chip->pcm_list, list) {
489 		if (as->fmt_type != fp->fmt_type)
490 			continue;
491 		subs = &as->substream[stream];
492 		if (subs->ep_num == fp->endpoint) {
493 			list_add_tail(&fp->list, &subs->fmt_list);
494 			subs->num_formats++;
495 			subs->formats |= fp->formats;
496 			return 0;
497 		}
498 	}
499 	/* look for an empty stream */
500 	list_for_each_entry(as, &chip->pcm_list, list) {
501 		if (as->fmt_type != fp->fmt_type)
502 			continue;
503 		subs = &as->substream[stream];
504 		if (subs->ep_num)
505 			continue;
506 		if (snd_device_get_state(chip->card, as->pcm) !=
507 		    SNDRV_DEV_BUILD)
508 			chip->need_delayed_register = true;
509 		err = snd_pcm_new_stream(as->pcm, stream, 1);
510 		if (err < 0)
511 			return err;
512 		snd_usb_init_substream(as, stream, fp, pd);
513 		return add_chmap(as->pcm, stream, subs);
514 	}
515 
516 	/* create a new pcm */
517 	as = kzalloc(sizeof(*as), GFP_KERNEL);
518 	if (!as)
519 		return -ENOMEM;
520 	as->pcm_index = chip->pcm_devs;
521 	as->chip = chip;
522 	as->fmt_type = fp->fmt_type;
523 	err = snd_pcm_new(chip->card, "USB Audio", chip->pcm_devs,
524 			  stream == SNDRV_PCM_STREAM_PLAYBACK ? 1 : 0,
525 			  stream == SNDRV_PCM_STREAM_PLAYBACK ? 0 : 1,
526 			  &pcm);
527 	if (err < 0) {
528 		kfree(as);
529 		return err;
530 	}
531 	as->pcm = pcm;
532 	pcm->private_data = as;
533 	pcm->private_free = snd_usb_audio_pcm_free;
534 	pcm->info_flags = 0;
535 	if (chip->pcm_devs > 0)
536 		sprintf(pcm->name, "USB Audio #%d", chip->pcm_devs);
537 	else
538 		strcpy(pcm->name, "USB Audio");
539 
540 	snd_usb_init_substream(as, stream, fp, pd);
541 
542 	/*
543 	 * Keep using head insertion for M-Audio Audiophile USB (tm) which has a
544 	 * fix to swap capture stream order in conf/cards/USB-audio.conf
545 	 */
546 	if (chip->usb_id == USB_ID(0x0763, 0x2003))
547 		list_add(&as->list, &chip->pcm_list);
548 	else
549 		list_add_tail(&as->list, &chip->pcm_list);
550 
551 	chip->pcm_devs++;
552 
553 	snd_usb_proc_pcm_format_add(as);
554 
555 	return add_chmap(pcm, stream, &as->substream[stream]);
556 }
557 
558 int snd_usb_add_audio_stream(struct snd_usb_audio *chip,
559 			     int stream,
560 			     struct audioformat *fp)
561 {
562 	return __snd_usb_add_audio_stream(chip, stream, fp, NULL);
563 }
564 
565 static int snd_usb_add_audio_stream_v3(struct snd_usb_audio *chip,
566 				       int stream,
567 				       struct audioformat *fp,
568 				       struct snd_usb_power_domain *pd)
569 {
570 	return __snd_usb_add_audio_stream(chip, stream, fp, pd);
571 }
572 
573 static int parse_uac_endpoint_attributes(struct snd_usb_audio *chip,
574 					 struct usb_host_interface *alts,
575 					 int protocol, int iface_no)
576 {
577 	/* parsed with a v1 header here. that's ok as we only look at the
578 	 * header first which is the same for both versions */
579 	struct uac_iso_endpoint_descriptor *csep;
580 	struct usb_interface_descriptor *altsd = get_iface_desc(alts);
581 	int attributes = 0;
582 
583 	csep = snd_usb_find_desc(alts->endpoint[0].extra, alts->endpoint[0].extralen, NULL, USB_DT_CS_ENDPOINT);
584 
585 	/* Creamware Noah has this descriptor after the 2nd endpoint */
586 	if (!csep && altsd->bNumEndpoints >= 2)
587 		csep = snd_usb_find_desc(alts->endpoint[1].extra, alts->endpoint[1].extralen, NULL, USB_DT_CS_ENDPOINT);
588 
589 	/*
590 	 * If we can't locate the USB_DT_CS_ENDPOINT descriptor in the extra
591 	 * bytes after the first endpoint, go search the entire interface.
592 	 * Some devices have it directly *before* the standard endpoint.
593 	 */
594 	if (!csep)
595 		csep = snd_usb_find_desc(alts->extra, alts->extralen, NULL, USB_DT_CS_ENDPOINT);
596 
597 	if (!csep || csep->bLength < 7 ||
598 	    csep->bDescriptorSubtype != UAC_EP_GENERAL)
599 		goto error;
600 
601 	if (protocol == UAC_VERSION_1) {
602 		attributes = csep->bmAttributes;
603 	} else if (protocol == UAC_VERSION_2) {
604 		struct uac2_iso_endpoint_descriptor *csep2 =
605 			(struct uac2_iso_endpoint_descriptor *) csep;
606 
607 		if (csep2->bLength < sizeof(*csep2))
608 			goto error;
609 		attributes = csep->bmAttributes & UAC_EP_CS_ATTR_FILL_MAX;
610 
611 		/* emulate the endpoint attributes of a v1 device */
612 		if (csep2->bmControls & UAC2_CONTROL_PITCH)
613 			attributes |= UAC_EP_CS_ATTR_PITCH_CONTROL;
614 	} else { /* UAC_VERSION_3 */
615 		struct uac3_iso_endpoint_descriptor *csep3 =
616 			(struct uac3_iso_endpoint_descriptor *) csep;
617 
618 		if (csep3->bLength < sizeof(*csep3))
619 			goto error;
620 		/* emulate the endpoint attributes of a v1 device */
621 		if (le32_to_cpu(csep3->bmControls) & UAC2_CONTROL_PITCH)
622 			attributes |= UAC_EP_CS_ATTR_PITCH_CONTROL;
623 	}
624 
625 	return attributes;
626 
627  error:
628 	usb_audio_warn(chip,
629 		       "%u:%d : no or invalid class specific endpoint descriptor\n",
630 		       iface_no, altsd->bAlternateSetting);
631 	return 0;
632 }
633 
634 /* find an input terminal descriptor (either UAC1 or UAC2) with the given
635  * terminal id
636  */
637 static void *
638 snd_usb_find_input_terminal_descriptor(struct usb_host_interface *ctrl_iface,
639 				       int terminal_id, int protocol)
640 {
641 	struct uac2_input_terminal_descriptor *term = NULL;
642 
643 	while ((term = snd_usb_find_csint_desc(ctrl_iface->extra,
644 					       ctrl_iface->extralen,
645 					       term, UAC_INPUT_TERMINAL))) {
646 		if (!snd_usb_validate_audio_desc(term, protocol))
647 			continue;
648 		if (term->bTerminalID == terminal_id)
649 			return term;
650 	}
651 
652 	return NULL;
653 }
654 
655 static void *
656 snd_usb_find_output_terminal_descriptor(struct usb_host_interface *ctrl_iface,
657 					int terminal_id, int protocol)
658 {
659 	/* OK to use with both UAC2 and UAC3 */
660 	struct uac2_output_terminal_descriptor *term = NULL;
661 
662 	while ((term = snd_usb_find_csint_desc(ctrl_iface->extra,
663 					       ctrl_iface->extralen,
664 					       term, UAC_OUTPUT_TERMINAL))) {
665 		if (!snd_usb_validate_audio_desc(term, protocol))
666 			continue;
667 		if (term->bTerminalID == terminal_id)
668 			return term;
669 	}
670 
671 	return NULL;
672 }
673 
674 static struct audioformat *
675 audio_format_alloc_init(struct snd_usb_audio *chip,
676 		       struct usb_host_interface *alts,
677 		       int protocol, int iface_no, int altset_idx,
678 		       int altno, int num_channels, int clock)
679 {
680 	struct audioformat *fp;
681 
682 	fp = kzalloc(sizeof(*fp), GFP_KERNEL);
683 	if (!fp)
684 		return NULL;
685 
686 	fp->iface = iface_no;
687 	fp->altsetting = altno;
688 	fp->altset_idx = altset_idx;
689 	fp->endpoint = get_endpoint(alts, 0)->bEndpointAddress;
690 	fp->ep_attr = get_endpoint(alts, 0)->bmAttributes;
691 	fp->datainterval = snd_usb_parse_datainterval(chip, alts);
692 	fp->protocol = protocol;
693 	fp->maxpacksize = le16_to_cpu(get_endpoint(alts, 0)->wMaxPacketSize);
694 	fp->channels = num_channels;
695 	if (snd_usb_get_speed(chip->dev) == USB_SPEED_HIGH)
696 		fp->maxpacksize = (((fp->maxpacksize >> 11) & 3) + 1)
697 				* (fp->maxpacksize & 0x7ff);
698 	fp->clock = clock;
699 	INIT_LIST_HEAD(&fp->list);
700 
701 	return fp;
702 }
703 
704 static struct audioformat *
705 snd_usb_get_audioformat_uac12(struct snd_usb_audio *chip,
706 			      struct usb_host_interface *alts,
707 			      int protocol, int iface_no, int altset_idx,
708 			      int altno, int stream, int bm_quirk)
709 {
710 	struct usb_device *dev = chip->dev;
711 	struct uac_format_type_i_continuous_descriptor *fmt;
712 	unsigned int num_channels = 0, chconfig = 0;
713 	struct audioformat *fp;
714 	int clock = 0;
715 	u64 format;
716 
717 	/* get audio formats */
718 	if (protocol == UAC_VERSION_1) {
719 		struct uac1_as_header_descriptor *as =
720 			snd_usb_find_csint_desc(alts->extra, alts->extralen,
721 						NULL, UAC_AS_GENERAL);
722 		struct uac_input_terminal_descriptor *iterm;
723 
724 		if (!as) {
725 			dev_err(&dev->dev,
726 				"%u:%d : UAC_AS_GENERAL descriptor not found\n",
727 				iface_no, altno);
728 			return NULL;
729 		}
730 
731 		if (as->bLength < sizeof(*as)) {
732 			dev_err(&dev->dev,
733 				"%u:%d : invalid UAC_AS_GENERAL desc\n",
734 				iface_no, altno);
735 			return NULL;
736 		}
737 
738 		format = le16_to_cpu(as->wFormatTag); /* remember the format value */
739 
740 		iterm = snd_usb_find_input_terminal_descriptor(chip->ctrl_intf,
741 							       as->bTerminalLink,
742 							       protocol);
743 		if (iterm) {
744 			num_channels = iterm->bNrChannels;
745 			chconfig = le16_to_cpu(iterm->wChannelConfig);
746 		}
747 	} else { /* UAC_VERSION_2 */
748 		struct uac2_input_terminal_descriptor *input_term;
749 		struct uac2_output_terminal_descriptor *output_term;
750 		struct uac2_as_header_descriptor *as =
751 			snd_usb_find_csint_desc(alts->extra, alts->extralen,
752 						NULL, UAC_AS_GENERAL);
753 
754 		if (!as) {
755 			dev_err(&dev->dev,
756 				"%u:%d : UAC_AS_GENERAL descriptor not found\n",
757 				iface_no, altno);
758 			return NULL;
759 		}
760 
761 		if (as->bLength < sizeof(*as)) {
762 			dev_err(&dev->dev,
763 				"%u:%d : invalid UAC_AS_GENERAL desc\n",
764 				iface_no, altno);
765 			return NULL;
766 		}
767 
768 		num_channels = as->bNrChannels;
769 		format = le32_to_cpu(as->bmFormats);
770 		chconfig = le32_to_cpu(as->bmChannelConfig);
771 
772 		/*
773 		 * lookup the terminal associated to this interface
774 		 * to extract the clock
775 		 */
776 		input_term = snd_usb_find_input_terminal_descriptor(chip->ctrl_intf,
777 								    as->bTerminalLink,
778 								    protocol);
779 		if (input_term) {
780 			clock = input_term->bCSourceID;
781 			if (!chconfig && (num_channels == input_term->bNrChannels))
782 				chconfig = le32_to_cpu(input_term->bmChannelConfig);
783 			goto found_clock;
784 		}
785 
786 		output_term = snd_usb_find_output_terminal_descriptor(chip->ctrl_intf,
787 								      as->bTerminalLink,
788 								      protocol);
789 		if (output_term) {
790 			clock = output_term->bCSourceID;
791 			goto found_clock;
792 		}
793 
794 		dev_err(&dev->dev,
795 			"%u:%d : bogus bTerminalLink %d\n",
796 			iface_no, altno, as->bTerminalLink);
797 		return NULL;
798 	}
799 
800 found_clock:
801 	/* get format type */
802 	fmt = snd_usb_find_csint_desc(alts->extra, alts->extralen,
803 				      NULL, UAC_FORMAT_TYPE);
804 	if (!fmt) {
805 		dev_err(&dev->dev,
806 			"%u:%d : no UAC_FORMAT_TYPE desc\n",
807 			iface_no, altno);
808 		return NULL;
809 	}
810 	if (((protocol == UAC_VERSION_1) && (fmt->bLength < 8))
811 			|| ((protocol == UAC_VERSION_2) &&
812 					(fmt->bLength < 6))) {
813 		dev_err(&dev->dev,
814 			"%u:%d : invalid UAC_FORMAT_TYPE desc\n",
815 			iface_no, altno);
816 		return NULL;
817 	}
818 
819 	/*
820 	 * Blue Microphones workaround: The last altsetting is
821 	 * identical with the previous one, except for a larger
822 	 * packet size, but is actually a mislabeled two-channel
823 	 * setting; ignore it.
824 	 *
825 	 * Part 2: analyze quirk flag and format
826 	 */
827 	if (bm_quirk && fmt->bNrChannels == 1 && fmt->bSubframeSize == 2)
828 		return NULL;
829 
830 	fp = audio_format_alloc_init(chip, alts, protocol, iface_no,
831 				     altset_idx, altno, num_channels, clock);
832 	if (!fp)
833 		return ERR_PTR(-ENOMEM);
834 
835 	fp->attributes = parse_uac_endpoint_attributes(chip, alts, protocol,
836 						       iface_no);
837 
838 	/* some quirks for attributes here */
839 	snd_usb_audioformat_attributes_quirk(chip, fp, stream);
840 
841 	/* ok, let's parse further... */
842 	if (snd_usb_parse_audio_format(chip, fp, format,
843 					fmt, stream) < 0) {
844 		audioformat_free(fp);
845 		return NULL;
846 	}
847 
848 	/* Create chmap */
849 	if (fp->channels != num_channels)
850 		chconfig = 0;
851 
852 	fp->chmap = convert_chmap(fp->channels, chconfig, protocol);
853 
854 	return fp;
855 }
856 
857 static struct audioformat *
858 snd_usb_get_audioformat_uac3(struct snd_usb_audio *chip,
859 			     struct usb_host_interface *alts,
860 			     struct snd_usb_power_domain **pd_out,
861 			     int iface_no, int altset_idx,
862 			     int altno, int stream)
863 {
864 	struct usb_device *dev = chip->dev;
865 	struct uac3_input_terminal_descriptor *input_term;
866 	struct uac3_output_terminal_descriptor *output_term;
867 	struct uac3_cluster_header_descriptor *cluster;
868 	struct uac3_as_header_descriptor *as = NULL;
869 	struct uac3_hc_descriptor_header hc_header;
870 	struct snd_pcm_chmap_elem *chmap;
871 	struct snd_usb_power_domain *pd;
872 	unsigned char badd_profile;
873 	u64 badd_formats = 0;
874 	unsigned int num_channels;
875 	struct audioformat *fp;
876 	u16 cluster_id, wLength;
877 	int clock = 0;
878 	int err;
879 
880 	badd_profile = chip->badd_profile;
881 
882 	if (badd_profile >= UAC3_FUNCTION_SUBCLASS_GENERIC_IO) {
883 		unsigned int maxpacksize =
884 			le16_to_cpu(get_endpoint(alts, 0)->wMaxPacketSize);
885 
886 		switch (maxpacksize) {
887 		default:
888 			dev_err(&dev->dev,
889 				"%u:%d : incorrect wMaxPacketSize for BADD profile\n",
890 				iface_no, altno);
891 			return NULL;
892 		case UAC3_BADD_EP_MAXPSIZE_SYNC_MONO_16:
893 		case UAC3_BADD_EP_MAXPSIZE_ASYNC_MONO_16:
894 			badd_formats = SNDRV_PCM_FMTBIT_S16_LE;
895 			num_channels = 1;
896 			break;
897 		case UAC3_BADD_EP_MAXPSIZE_SYNC_MONO_24:
898 		case UAC3_BADD_EP_MAXPSIZE_ASYNC_MONO_24:
899 			badd_formats = SNDRV_PCM_FMTBIT_S24_3LE;
900 			num_channels = 1;
901 			break;
902 		case UAC3_BADD_EP_MAXPSIZE_SYNC_STEREO_16:
903 		case UAC3_BADD_EP_MAXPSIZE_ASYNC_STEREO_16:
904 			badd_formats = SNDRV_PCM_FMTBIT_S16_LE;
905 			num_channels = 2;
906 			break;
907 		case UAC3_BADD_EP_MAXPSIZE_SYNC_STEREO_24:
908 		case UAC3_BADD_EP_MAXPSIZE_ASYNC_STEREO_24:
909 			badd_formats = SNDRV_PCM_FMTBIT_S24_3LE;
910 			num_channels = 2;
911 			break;
912 		}
913 
914 		chmap = kzalloc(sizeof(*chmap), GFP_KERNEL);
915 		if (!chmap)
916 			return ERR_PTR(-ENOMEM);
917 
918 		if (num_channels == 1) {
919 			chmap->map[0] = SNDRV_CHMAP_MONO;
920 		} else {
921 			chmap->map[0] = SNDRV_CHMAP_FL;
922 			chmap->map[1] = SNDRV_CHMAP_FR;
923 		}
924 
925 		chmap->channels = num_channels;
926 		clock = UAC3_BADD_CS_ID9;
927 		goto found_clock;
928 	}
929 
930 	as = snd_usb_find_csint_desc(alts->extra, alts->extralen,
931 				     NULL, UAC_AS_GENERAL);
932 	if (!as) {
933 		dev_err(&dev->dev,
934 			"%u:%d : UAC_AS_GENERAL descriptor not found\n",
935 			iface_no, altno);
936 		return NULL;
937 	}
938 
939 	if (as->bLength < sizeof(*as)) {
940 		dev_err(&dev->dev,
941 			"%u:%d : invalid UAC_AS_GENERAL desc\n",
942 			iface_no, altno);
943 		return NULL;
944 	}
945 
946 	cluster_id = le16_to_cpu(as->wClusterDescrID);
947 	if (!cluster_id) {
948 		dev_err(&dev->dev,
949 			"%u:%d : no cluster descriptor\n",
950 			iface_no, altno);
951 		return NULL;
952 	}
953 
954 	/*
955 	 * Get number of channels and channel map through
956 	 * High Capability Cluster Descriptor
957 	 *
958 	 * First step: get High Capability header and
959 	 * read size of Cluster Descriptor
960 	 */
961 	err = snd_usb_ctl_msg(chip->dev,
962 			usb_rcvctrlpipe(chip->dev, 0),
963 			UAC3_CS_REQ_HIGH_CAPABILITY_DESCRIPTOR,
964 			USB_RECIP_INTERFACE | USB_TYPE_CLASS | USB_DIR_IN,
965 			cluster_id,
966 			snd_usb_ctrl_intf(chip),
967 			&hc_header, sizeof(hc_header));
968 	if (err < 0)
969 		return ERR_PTR(err);
970 	else if (err != sizeof(hc_header)) {
971 		dev_err(&dev->dev,
972 			"%u:%d : can't get High Capability descriptor\n",
973 			iface_no, altno);
974 		return ERR_PTR(-EIO);
975 	}
976 
977 	/*
978 	 * Second step: allocate needed amount of memory
979 	 * and request Cluster Descriptor
980 	 */
981 	wLength = le16_to_cpu(hc_header.wLength);
982 	cluster = kzalloc(wLength, GFP_KERNEL);
983 	if (!cluster)
984 		return ERR_PTR(-ENOMEM);
985 	err = snd_usb_ctl_msg(chip->dev,
986 			usb_rcvctrlpipe(chip->dev, 0),
987 			UAC3_CS_REQ_HIGH_CAPABILITY_DESCRIPTOR,
988 			USB_RECIP_INTERFACE | USB_TYPE_CLASS | USB_DIR_IN,
989 			cluster_id,
990 			snd_usb_ctrl_intf(chip),
991 			cluster, wLength);
992 	if (err < 0) {
993 		kfree(cluster);
994 		return ERR_PTR(err);
995 	} else if (err != wLength) {
996 		dev_err(&dev->dev,
997 			"%u:%d : can't get Cluster Descriptor\n",
998 			iface_no, altno);
999 		kfree(cluster);
1000 		return ERR_PTR(-EIO);
1001 	}
1002 
1003 	num_channels = cluster->bNrChannels;
1004 	chmap = convert_chmap_v3(cluster);
1005 	kfree(cluster);
1006 
1007 	/*
1008 	 * lookup the terminal associated to this interface
1009 	 * to extract the clock
1010 	 */
1011 	input_term = snd_usb_find_input_terminal_descriptor(chip->ctrl_intf,
1012 							    as->bTerminalLink,
1013 							    UAC_VERSION_3);
1014 	if (input_term) {
1015 		clock = input_term->bCSourceID;
1016 		goto found_clock;
1017 	}
1018 
1019 	output_term = snd_usb_find_output_terminal_descriptor(chip->ctrl_intf,
1020 							      as->bTerminalLink,
1021 							      UAC_VERSION_3);
1022 	if (output_term) {
1023 		clock = output_term->bCSourceID;
1024 		goto found_clock;
1025 	}
1026 
1027 	dev_err(&dev->dev, "%u:%d : bogus bTerminalLink %d\n",
1028 			iface_no, altno, as->bTerminalLink);
1029 	kfree(chmap);
1030 	return NULL;
1031 
1032 found_clock:
1033 	fp = audio_format_alloc_init(chip, alts, UAC_VERSION_3, iface_no,
1034 				     altset_idx, altno, num_channels, clock);
1035 	if (!fp) {
1036 		kfree(chmap);
1037 		return ERR_PTR(-ENOMEM);
1038 	}
1039 
1040 	fp->chmap = chmap;
1041 
1042 	if (badd_profile >= UAC3_FUNCTION_SUBCLASS_GENERIC_IO) {
1043 		fp->attributes = 0; /* No attributes */
1044 
1045 		fp->fmt_type = UAC_FORMAT_TYPE_I;
1046 		fp->formats = badd_formats;
1047 
1048 		fp->nr_rates = 0;	/* SNDRV_PCM_RATE_CONTINUOUS */
1049 		fp->rate_min = UAC3_BADD_SAMPLING_RATE;
1050 		fp->rate_max = UAC3_BADD_SAMPLING_RATE;
1051 		fp->rates = SNDRV_PCM_RATE_CONTINUOUS;
1052 
1053 		pd = kzalloc(sizeof(*pd), GFP_KERNEL);
1054 		if (!pd) {
1055 			audioformat_free(fp);
1056 			return NULL;
1057 		}
1058 		pd->pd_id = (stream == SNDRV_PCM_STREAM_PLAYBACK) ?
1059 					UAC3_BADD_PD_ID10 : UAC3_BADD_PD_ID11;
1060 		pd->pd_d1d0_rec = UAC3_BADD_PD_RECOVER_D1D0;
1061 		pd->pd_d2d0_rec = UAC3_BADD_PD_RECOVER_D2D0;
1062 
1063 	} else {
1064 		fp->attributes = parse_uac_endpoint_attributes(chip, alts,
1065 							       UAC_VERSION_3,
1066 							       iface_no);
1067 
1068 		pd = snd_usb_find_power_domain(chip->ctrl_intf,
1069 					       as->bTerminalLink);
1070 
1071 		/* ok, let's parse further... */
1072 		if (snd_usb_parse_audio_format_v3(chip, fp, as, stream) < 0) {
1073 			kfree(pd);
1074 			audioformat_free(fp);
1075 			return NULL;
1076 		}
1077 	}
1078 
1079 	if (pd)
1080 		*pd_out = pd;
1081 
1082 	return fp;
1083 }
1084 
1085 static int __snd_usb_parse_audio_interface(struct snd_usb_audio *chip,
1086 					   int iface_no,
1087 					   bool *has_non_pcm, bool non_pcm)
1088 {
1089 	struct usb_device *dev;
1090 	struct usb_interface *iface;
1091 	struct usb_host_interface *alts;
1092 	struct usb_interface_descriptor *altsd;
1093 	int i, altno, err, stream;
1094 	struct audioformat *fp = NULL;
1095 	struct snd_usb_power_domain *pd = NULL;
1096 	int num, protocol;
1097 
1098 	dev = chip->dev;
1099 
1100 	/* parse the interface's altsettings */
1101 	iface = usb_ifnum_to_if(dev, iface_no);
1102 
1103 	num = iface->num_altsetting;
1104 
1105 	/*
1106 	 * Dallas DS4201 workaround: It presents 5 altsettings, but the last
1107 	 * one misses syncpipe, and does not produce any sound.
1108 	 */
1109 	if (chip->usb_id == USB_ID(0x04fa, 0x4201))
1110 		num = 4;
1111 
1112 	for (i = 0; i < num; i++) {
1113 		alts = &iface->altsetting[i];
1114 		altsd = get_iface_desc(alts);
1115 		protocol = altsd->bInterfaceProtocol;
1116 		/* skip invalid one */
1117 		if (((altsd->bInterfaceClass != USB_CLASS_AUDIO ||
1118 		      (altsd->bInterfaceSubClass != USB_SUBCLASS_AUDIOSTREAMING &&
1119 		       altsd->bInterfaceSubClass != USB_SUBCLASS_VENDOR_SPEC)) &&
1120 		     altsd->bInterfaceClass != USB_CLASS_VENDOR_SPEC) ||
1121 		    altsd->bNumEndpoints < 1 ||
1122 		    le16_to_cpu(get_endpoint(alts, 0)->wMaxPacketSize) == 0)
1123 			continue;
1124 		/* must be isochronous */
1125 		if ((get_endpoint(alts, 0)->bmAttributes & USB_ENDPOINT_XFERTYPE_MASK) !=
1126 		    USB_ENDPOINT_XFER_ISOC)
1127 			continue;
1128 		/* check direction */
1129 		stream = (get_endpoint(alts, 0)->bEndpointAddress & USB_DIR_IN) ?
1130 			SNDRV_PCM_STREAM_CAPTURE : SNDRV_PCM_STREAM_PLAYBACK;
1131 		altno = altsd->bAlternateSetting;
1132 
1133 		if (snd_usb_apply_interface_quirk(chip, iface_no, altno))
1134 			continue;
1135 
1136 		/*
1137 		 * Roland audio streaming interfaces are marked with protocols
1138 		 * 0/1/2, but are UAC 1 compatible.
1139 		 */
1140 		if (USB_ID_VENDOR(chip->usb_id) == 0x0582 &&
1141 		    altsd->bInterfaceClass == USB_CLASS_VENDOR_SPEC &&
1142 		    protocol <= 2)
1143 			protocol = UAC_VERSION_1;
1144 
1145 		switch (protocol) {
1146 		default:
1147 			dev_dbg(&dev->dev, "%u:%d: unknown interface protocol %#02x, assuming v1\n",
1148 				iface_no, altno, protocol);
1149 			protocol = UAC_VERSION_1;
1150 			fallthrough;
1151 		case UAC_VERSION_1:
1152 		case UAC_VERSION_2: {
1153 			int bm_quirk = 0;
1154 
1155 			/*
1156 			 * Blue Microphones workaround: The last altsetting is
1157 			 * identical with the previous one, except for a larger
1158 			 * packet size, but is actually a mislabeled two-channel
1159 			 * setting; ignore it.
1160 			 *
1161 			 * Part 1: prepare quirk flag
1162 			 */
1163 			if (altno == 2 && num == 3 &&
1164 			    fp && fp->altsetting == 1 && fp->channels == 1 &&
1165 			    fp->formats == SNDRV_PCM_FMTBIT_S16_LE &&
1166 			    protocol == UAC_VERSION_1 &&
1167 			    le16_to_cpu(get_endpoint(alts, 0)->wMaxPacketSize) ==
1168 							fp->maxpacksize * 2)
1169 				bm_quirk = 1;
1170 
1171 			fp = snd_usb_get_audioformat_uac12(chip, alts, protocol,
1172 							   iface_no, i, altno,
1173 							   stream, bm_quirk);
1174 			break;
1175 		}
1176 		case UAC_VERSION_3:
1177 			fp = snd_usb_get_audioformat_uac3(chip, alts, &pd,
1178 						iface_no, i, altno, stream);
1179 			break;
1180 		}
1181 
1182 		if (!fp)
1183 			continue;
1184 		else if (IS_ERR(fp))
1185 			return PTR_ERR(fp);
1186 
1187 		if (fp->fmt_type != UAC_FORMAT_TYPE_I)
1188 			*has_non_pcm = true;
1189 		if ((fp->fmt_type == UAC_FORMAT_TYPE_I) == non_pcm) {
1190 			audioformat_free(fp);
1191 			kfree(pd);
1192 			fp = NULL;
1193 			pd = NULL;
1194 			continue;
1195 		}
1196 
1197 		dev_dbg(&dev->dev, "%u:%d: add audio endpoint %#x\n", iface_no, altno, fp->endpoint);
1198 		if (protocol == UAC_VERSION_3)
1199 			err = snd_usb_add_audio_stream_v3(chip, stream, fp, pd);
1200 		else
1201 			err = snd_usb_add_audio_stream(chip, stream, fp);
1202 
1203 		if (err < 0) {
1204 			audioformat_free(fp);
1205 			kfree(pd);
1206 			return err;
1207 		}
1208 		/* try to set the interface... */
1209 		usb_set_interface(chip->dev, iface_no, altno);
1210 		snd_usb_init_pitch(chip, iface_no, alts, fp);
1211 		snd_usb_init_sample_rate(chip, iface_no, alts, fp, fp->rate_max);
1212 	}
1213 	return 0;
1214 }
1215 
1216 int snd_usb_parse_audio_interface(struct snd_usb_audio *chip, int iface_no)
1217 {
1218 	int err;
1219 	bool has_non_pcm = false;
1220 
1221 	/* parse PCM formats */
1222 	err = __snd_usb_parse_audio_interface(chip, iface_no, &has_non_pcm, false);
1223 	if (err < 0)
1224 		return err;
1225 
1226 	if (has_non_pcm) {
1227 		/* parse non-PCM formats */
1228 		err = __snd_usb_parse_audio_interface(chip, iface_no, &has_non_pcm, true);
1229 		if (err < 0)
1230 			return err;
1231 	}
1232 
1233 	return 0;
1234 }
1235 
1236