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   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
  31static 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 */
  42static 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->str_pd);
  51	snd_media_stream_delete(subs);
  52}
  53
  54
  55/*
  56 * free a usb stream instance
  57 */
  58static void snd_usb_audio_stream_free(struct snd_usb_stream *stream)
  59{
  60	free_substream(&stream->substream[0]);
  61	free_substream(&stream->substream[1]);
  62	list_del(&stream->list);
  63	kfree(stream);
  64}
  65
  66static void snd_usb_audio_pcm_free(struct snd_pcm *pcm)
  67{
  68	struct snd_usb_stream *stream = pcm->private_data;
  69	if (stream) {
  70		stream->pcm = NULL;
  71		snd_usb_audio_stream_free(stream);
  72	}
  73}
  74
  75/*
  76 * initialize the substream instance.
  77 */
  78
  79static void snd_usb_init_substream(struct snd_usb_stream *as,
  80				   int stream,
  81				   struct audioformat *fp,
  82				   struct snd_usb_power_domain *pd)
  83{
  84	struct snd_usb_substream *subs = &as->substream[stream];
  85
  86	INIT_LIST_HEAD(&subs->fmt_list);
  87	spin_lock_init(&subs->lock);
  88
  89	subs->stream = as;
  90	subs->direction = stream;
  91	subs->dev = as->chip->dev;
  92	subs->txfr_quirk = as->chip->txfr_quirk;
  93	subs->tx_length_quirk = as->chip->tx_length_quirk;
  94	subs->speed = snd_usb_get_speed(subs->dev);
  95	subs->pkt_offset_adj = 0;
  96	subs->stream_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 */
 119static 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 */
 133static 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
 146static 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
 189static 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 = 0;
 196
 197	if (subs->cur_audiofmt)
 198		chmap = subs->cur_audiofmt->chmap;
 199	if (chmap) {
 200		for (i = 0; i < chmap->channels; i++)
 201			ucontrol->value.integer.value[i] = chmap->map[i];
 202	}
 203	for (; i < subs->channels_max; i++)
 204		ucontrol->value.integer.value[i] = 0;
 205	return 0;
 206}
 207
 208/* create a chmap kctl assigned to the given USB substream */
 209static 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 */
 239static struct snd_pcm_chmap_elem *convert_chmap(int channels, unsigned int bits,
 240						int protocol)
 241{
 242	static const 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 const 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 */
 323static struct
 324snd_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 */
 476static 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		if (snd_device_get_state(chip->card, as->pcm) !=
 506		    SNDRV_DEV_BUILD)
 507			chip->need_delayed_register = true;
 508		err = snd_pcm_new_stream(as->pcm, stream, 1);
 509		if (err < 0)
 510			return err;
 511		snd_usb_init_substream(as, stream, fp, pd);
 512		return add_chmap(as->pcm, stream, subs);
 513	}
 514
 515	/* create a new pcm */
 516	as = kzalloc(sizeof(*as), GFP_KERNEL);
 517	if (!as)
 518		return -ENOMEM;
 519	as->pcm_index = chip->pcm_devs;
 520	as->chip = chip;
 521	as->fmt_type = fp->fmt_type;
 522	err = snd_pcm_new(chip->card, "USB Audio", chip->pcm_devs,
 523			  stream == SNDRV_PCM_STREAM_PLAYBACK ? 1 : 0,
 524			  stream == SNDRV_PCM_STREAM_PLAYBACK ? 0 : 1,
 525			  &pcm);
 526	if (err < 0) {
 527		kfree(as);
 528		return err;
 529	}
 530	as->pcm = pcm;
 531	pcm->private_data = as;
 532	pcm->private_free = snd_usb_audio_pcm_free;
 533	pcm->info_flags = 0;
 534	if (chip->pcm_devs > 0)
 535		sprintf(pcm->name, "USB Audio #%d", chip->pcm_devs);
 536	else
 537		strcpy(pcm->name, "USB Audio");
 538
 539	snd_usb_init_substream(as, stream, fp, pd);
 540
 541	/*
 542	 * Keep using head insertion for M-Audio Audiophile USB (tm) which has a
 543	 * fix to swap capture stream order in conf/cards/USB-audio.conf
 544	 */
 545	if (chip->usb_id == USB_ID(0x0763, 0x2003))
 546		list_add(&as->list, &chip->pcm_list);
 547	else
 548		list_add_tail(&as->list, &chip->pcm_list);
 549
 550	chip->pcm_devs++;
 551
 552	snd_usb_proc_pcm_format_add(as);
 553
 554	return add_chmap(pcm, stream, &as->substream[stream]);
 555}
 556
 557int snd_usb_add_audio_stream(struct snd_usb_audio *chip,
 558			     int stream,
 559			     struct audioformat *fp)
 560{
 561	return __snd_usb_add_audio_stream(chip, stream, fp, NULL);
 562}
 563
 564static int snd_usb_add_audio_stream_v3(struct snd_usb_audio *chip,
 565				       int stream,
 566				       struct audioformat *fp,
 567				       struct snd_usb_power_domain *pd)
 568{
 569	return __snd_usb_add_audio_stream(chip, stream, fp, pd);
 570}
 571
 572static int parse_uac_endpoint_attributes(struct snd_usb_audio *chip,
 573					 struct usb_host_interface *alts,
 574					 int protocol, int iface_no)
 575{
 576	/* parsed with a v1 header here. that's ok as we only look at the
 577	 * header first which is the same for both versions */
 578	struct uac_iso_endpoint_descriptor *csep;
 579	struct usb_interface_descriptor *altsd = get_iface_desc(alts);
 580	int attributes = 0;
 581
 582	csep = snd_usb_find_desc(alts->endpoint[0].extra, alts->endpoint[0].extralen, NULL, USB_DT_CS_ENDPOINT);
 583
 584	/* Creamware Noah has this descriptor after the 2nd endpoint */
 585	if (!csep && altsd->bNumEndpoints >= 2)
 586		csep = snd_usb_find_desc(alts->endpoint[1].extra, alts->endpoint[1].extralen, NULL, USB_DT_CS_ENDPOINT);
 587
 588	/*
 589	 * If we can't locate the USB_DT_CS_ENDPOINT descriptor in the extra
 590	 * bytes after the first endpoint, go search the entire interface.
 591	 * Some devices have it directly *before* the standard endpoint.
 592	 */
 593	if (!csep)
 594		csep = snd_usb_find_desc(alts->extra, alts->extralen, NULL, USB_DT_CS_ENDPOINT);
 595
 596	if (!csep || csep->bLength < 7 ||
 597	    csep->bDescriptorSubtype != UAC_EP_GENERAL)
 598		goto error;
 599
 600	if (protocol == UAC_VERSION_1) {
 601		attributes = csep->bmAttributes;
 602	} else if (protocol == UAC_VERSION_2) {
 603		struct uac2_iso_endpoint_descriptor *csep2 =
 604			(struct uac2_iso_endpoint_descriptor *) csep;
 605
 606		if (csep2->bLength < sizeof(*csep2))
 607			goto error;
 608		attributes = csep->bmAttributes & UAC_EP_CS_ATTR_FILL_MAX;
 609
 610		/* emulate the endpoint attributes of a v1 device */
 611		if (csep2->bmControls & UAC2_CONTROL_PITCH)
 612			attributes |= UAC_EP_CS_ATTR_PITCH_CONTROL;
 613	} else { /* UAC_VERSION_3 */
 614		struct uac3_iso_endpoint_descriptor *csep3 =
 615			(struct uac3_iso_endpoint_descriptor *) csep;
 616
 617		if (csep3->bLength < sizeof(*csep3))
 618			goto error;
 619		/* emulate the endpoint attributes of a v1 device */
 620		if (le32_to_cpu(csep3->bmControls) & UAC2_CONTROL_PITCH)
 621			attributes |= UAC_EP_CS_ATTR_PITCH_CONTROL;
 622	}
 623
 624	return attributes;
 625
 626 error:
 627	usb_audio_warn(chip,
 628		       "%u:%d : no or invalid class specific endpoint descriptor\n",
 629		       iface_no, altsd->bAlternateSetting);
 630	return 0;
 631}
 632
 633/* find an input terminal descriptor (either UAC1 or UAC2) with the given
 634 * terminal id
 635 */
 636static void *
 637snd_usb_find_input_terminal_descriptor(struct usb_host_interface *ctrl_iface,
 638				       int terminal_id, int protocol)
 639{
 640	struct uac2_input_terminal_descriptor *term = NULL;
 641
 642	while ((term = snd_usb_find_csint_desc(ctrl_iface->extra,
 643					       ctrl_iface->extralen,
 644					       term, UAC_INPUT_TERMINAL))) {
 645		if (!snd_usb_validate_audio_desc(term, protocol))
 646			continue;
 647		if (term->bTerminalID == terminal_id)
 648			return term;
 649	}
 650
 651	return NULL;
 652}
 653
 654static void *
 655snd_usb_find_output_terminal_descriptor(struct usb_host_interface *ctrl_iface,
 656					int terminal_id, int protocol)
 657{
 658	/* OK to use with both UAC2 and UAC3 */
 659	struct uac2_output_terminal_descriptor *term = NULL;
 660
 661	while ((term = snd_usb_find_csint_desc(ctrl_iface->extra,
 662					       ctrl_iface->extralen,
 663					       term, UAC_OUTPUT_TERMINAL))) {
 664		if (!snd_usb_validate_audio_desc(term, protocol))
 665			continue;
 666		if (term->bTerminalID == terminal_id)
 667			return term;
 668	}
 669
 670	return NULL;
 671}
 672
 673static struct audioformat *
 674audio_format_alloc_init(struct snd_usb_audio *chip,
 675		       struct usb_host_interface *alts,
 676		       int protocol, int iface_no, int altset_idx,
 677		       int altno, int num_channels, int clock)
 678{
 679	struct audioformat *fp;
 680
 681	fp = kzalloc(sizeof(*fp), GFP_KERNEL);
 682	if (!fp)
 683		return NULL;
 684
 685	fp->iface = iface_no;
 686	fp->altsetting = altno;
 687	fp->altset_idx = altset_idx;
 688	fp->endpoint = get_endpoint(alts, 0)->bEndpointAddress;
 689	fp->ep_attr = get_endpoint(alts, 0)->bmAttributes;
 690	fp->datainterval = snd_usb_parse_datainterval(chip, alts);
 691	fp->protocol = protocol;
 692	fp->maxpacksize = le16_to_cpu(get_endpoint(alts, 0)->wMaxPacketSize);
 693	fp->channels = num_channels;
 694	if (snd_usb_get_speed(chip->dev) == USB_SPEED_HIGH)
 695		fp->maxpacksize = (((fp->maxpacksize >> 11) & 3) + 1)
 696				* (fp->maxpacksize & 0x7ff);
 697	fp->clock = clock;
 698	INIT_LIST_HEAD(&fp->list);
 699
 700	return fp;
 701}
 702
 703static struct audioformat *
 704snd_usb_get_audioformat_uac12(struct snd_usb_audio *chip,
 705			      struct usb_host_interface *alts,
 706			      int protocol, int iface_no, int altset_idx,
 707			      int altno, int stream, int bm_quirk)
 708{
 709	struct usb_device *dev = chip->dev;
 710	struct uac_format_type_i_continuous_descriptor *fmt;
 711	unsigned int num_channels = 0, chconfig = 0;
 712	struct audioformat *fp;
 713	int clock = 0;
 714	u64 format;
 715
 716	/* get audio formats */
 717	if (protocol == UAC_VERSION_1) {
 718		struct uac1_as_header_descriptor *as =
 719			snd_usb_find_csint_desc(alts->extra, alts->extralen,
 720						NULL, UAC_AS_GENERAL);
 721		struct uac_input_terminal_descriptor *iterm;
 722
 723		if (!as) {
 724			dev_err(&dev->dev,
 725				"%u:%d : UAC_AS_GENERAL descriptor not found\n",
 726				iface_no, altno);
 727			return NULL;
 728		}
 729
 730		if (as->bLength < sizeof(*as)) {
 731			dev_err(&dev->dev,
 732				"%u:%d : invalid UAC_AS_GENERAL desc\n",
 733				iface_no, altno);
 734			return NULL;
 735		}
 736
 737		format = le16_to_cpu(as->wFormatTag); /* remember the format value */
 738
 739		iterm = snd_usb_find_input_terminal_descriptor(chip->ctrl_intf,
 740							       as->bTerminalLink,
 741							       protocol);
 742		if (iterm) {
 743			num_channels = iterm->bNrChannels;
 744			chconfig = le16_to_cpu(iterm->wChannelConfig);
 745		}
 746	} else { /* UAC_VERSION_2 */
 747		struct uac2_input_terminal_descriptor *input_term;
 748		struct uac2_output_terminal_descriptor *output_term;
 749		struct uac2_as_header_descriptor *as =
 750			snd_usb_find_csint_desc(alts->extra, alts->extralen,
 751						NULL, UAC_AS_GENERAL);
 752
 753		if (!as) {
 754			dev_err(&dev->dev,
 755				"%u:%d : UAC_AS_GENERAL descriptor not found\n",
 756				iface_no, altno);
 757			return NULL;
 758		}
 759
 760		if (as->bLength < sizeof(*as)) {
 761			dev_err(&dev->dev,
 762				"%u:%d : invalid UAC_AS_GENERAL desc\n",
 763				iface_no, altno);
 764			return NULL;
 765		}
 766
 767		num_channels = as->bNrChannels;
 768		format = le32_to_cpu(as->bmFormats);
 769		chconfig = le32_to_cpu(as->bmChannelConfig);
 770
 771		/*
 772		 * lookup the terminal associated to this interface
 773		 * to extract the clock
 774		 */
 775		input_term = snd_usb_find_input_terminal_descriptor(chip->ctrl_intf,
 776								    as->bTerminalLink,
 777								    protocol);
 778		if (input_term) {
 779			clock = input_term->bCSourceID;
 780			if (!chconfig && (num_channels == input_term->bNrChannels))
 781				chconfig = le32_to_cpu(input_term->bmChannelConfig);
 782			goto found_clock;
 783		}
 784
 785		output_term = snd_usb_find_output_terminal_descriptor(chip->ctrl_intf,
 786								      as->bTerminalLink,
 787								      protocol);
 788		if (output_term) {
 789			clock = output_term->bCSourceID;
 790			goto found_clock;
 791		}
 792
 793		dev_err(&dev->dev,
 794			"%u:%d : bogus bTerminalLink %d\n",
 795			iface_no, altno, as->bTerminalLink);
 796		return NULL;
 797	}
 798
 799found_clock:
 800	/* get format type */
 801	fmt = snd_usb_find_csint_desc(alts->extra, alts->extralen,
 802				      NULL, UAC_FORMAT_TYPE);
 803	if (!fmt) {
 804		dev_err(&dev->dev,
 805			"%u:%d : no UAC_FORMAT_TYPE desc\n",
 806			iface_no, altno);
 807		return NULL;
 808	}
 809	if (((protocol == UAC_VERSION_1) && (fmt->bLength < 8))
 810			|| ((protocol == UAC_VERSION_2) &&
 811					(fmt->bLength < 6))) {
 812		dev_err(&dev->dev,
 813			"%u:%d : invalid UAC_FORMAT_TYPE desc\n",
 814			iface_no, altno);
 815		return NULL;
 816	}
 817
 818	/*
 819	 * Blue Microphones workaround: The last altsetting is
 820	 * identical with the previous one, except for a larger
 821	 * packet size, but is actually a mislabeled two-channel
 822	 * setting; ignore it.
 823	 *
 824	 * Part 2: analyze quirk flag and format
 825	 */
 826	if (bm_quirk && fmt->bNrChannels == 1 && fmt->bSubframeSize == 2)
 827		return NULL;
 828
 829	fp = audio_format_alloc_init(chip, alts, protocol, iface_no,
 830				     altset_idx, altno, num_channels, clock);
 831	if (!fp)
 832		return ERR_PTR(-ENOMEM);
 833
 834	fp->attributes = parse_uac_endpoint_attributes(chip, alts, protocol,
 835						       iface_no);
 836
 837	/* some quirks for attributes here */
 838	snd_usb_audioformat_attributes_quirk(chip, fp, stream);
 839
 840	/* ok, let's parse further... */
 841	if (snd_usb_parse_audio_format(chip, fp, format,
 842					fmt, stream) < 0) {
 843		audioformat_free(fp);
 844		return NULL;
 845	}
 846
 847	/* Create chmap */
 848	if (fp->channels != num_channels)
 849		chconfig = 0;
 850
 851	fp->chmap = convert_chmap(fp->channels, chconfig, protocol);
 852
 853	return fp;
 854}
 855
 856static struct audioformat *
 857snd_usb_get_audioformat_uac3(struct snd_usb_audio *chip,
 858			     struct usb_host_interface *alts,
 859			     struct snd_usb_power_domain **pd_out,
 860			     int iface_no, int altset_idx,
 861			     int altno, int stream)
 862{
 863	struct usb_device *dev = chip->dev;
 864	struct uac3_input_terminal_descriptor *input_term;
 865	struct uac3_output_terminal_descriptor *output_term;
 866	struct uac3_cluster_header_descriptor *cluster;
 867	struct uac3_as_header_descriptor *as = NULL;
 868	struct uac3_hc_descriptor_header hc_header;
 869	struct snd_pcm_chmap_elem *chmap;
 870	struct snd_usb_power_domain *pd;
 871	unsigned char badd_profile;
 872	u64 badd_formats = 0;
 873	unsigned int num_channels;
 874	struct audioformat *fp;
 875	u16 cluster_id, wLength;
 876	int clock = 0;
 877	int err;
 878
 879	badd_profile = chip->badd_profile;
 880
 881	if (badd_profile >= UAC3_FUNCTION_SUBCLASS_GENERIC_IO) {
 882		unsigned int maxpacksize =
 883			le16_to_cpu(get_endpoint(alts, 0)->wMaxPacketSize);
 884
 885		switch (maxpacksize) {
 886		default:
 887			dev_err(&dev->dev,
 888				"%u:%d : incorrect wMaxPacketSize for BADD profile\n",
 889				iface_no, altno);
 890			return NULL;
 891		case UAC3_BADD_EP_MAXPSIZE_SYNC_MONO_16:
 892		case UAC3_BADD_EP_MAXPSIZE_ASYNC_MONO_16:
 893			badd_formats = SNDRV_PCM_FMTBIT_S16_LE;
 894			num_channels = 1;
 895			break;
 896		case UAC3_BADD_EP_MAXPSIZE_SYNC_MONO_24:
 897		case UAC3_BADD_EP_MAXPSIZE_ASYNC_MONO_24:
 898			badd_formats = SNDRV_PCM_FMTBIT_S24_3LE;
 899			num_channels = 1;
 900			break;
 901		case UAC3_BADD_EP_MAXPSIZE_SYNC_STEREO_16:
 902		case UAC3_BADD_EP_MAXPSIZE_ASYNC_STEREO_16:
 903			badd_formats = SNDRV_PCM_FMTBIT_S16_LE;
 904			num_channels = 2;
 905			break;
 906		case UAC3_BADD_EP_MAXPSIZE_SYNC_STEREO_24:
 907		case UAC3_BADD_EP_MAXPSIZE_ASYNC_STEREO_24:
 908			badd_formats = SNDRV_PCM_FMTBIT_S24_3LE;
 909			num_channels = 2;
 910			break;
 911		}
 912
 913		chmap = kzalloc(sizeof(*chmap), GFP_KERNEL);
 914		if (!chmap)
 915			return ERR_PTR(-ENOMEM);
 916
 917		if (num_channels == 1) {
 918			chmap->map[0] = SNDRV_CHMAP_MONO;
 919		} else {
 920			chmap->map[0] = SNDRV_CHMAP_FL;
 921			chmap->map[1] = SNDRV_CHMAP_FR;
 922		}
 923
 924		chmap->channels = num_channels;
 925		clock = UAC3_BADD_CS_ID9;
 926		goto found_clock;
 927	}
 928
 929	as = snd_usb_find_csint_desc(alts->extra, alts->extralen,
 930				     NULL, UAC_AS_GENERAL);
 931	if (!as) {
 932		dev_err(&dev->dev,
 933			"%u:%d : UAC_AS_GENERAL descriptor not found\n",
 934			iface_no, altno);
 935		return NULL;
 936	}
 937
 938	if (as->bLength < sizeof(*as)) {
 939		dev_err(&dev->dev,
 940			"%u:%d : invalid UAC_AS_GENERAL desc\n",
 941			iface_no, altno);
 942		return NULL;
 943	}
 944
 945	cluster_id = le16_to_cpu(as->wClusterDescrID);
 946	if (!cluster_id) {
 947		dev_err(&dev->dev,
 948			"%u:%d : no cluster descriptor\n",
 949			iface_no, altno);
 950		return NULL;
 951	}
 952
 953	/*
 954	 * Get number of channels and channel map through
 955	 * High Capability Cluster Descriptor
 956	 *
 957	 * First step: get High Capability header and
 958	 * read size of Cluster Descriptor
 959	 */
 960	err = snd_usb_ctl_msg(chip->dev,
 961			usb_rcvctrlpipe(chip->dev, 0),
 962			UAC3_CS_REQ_HIGH_CAPABILITY_DESCRIPTOR,
 963			USB_RECIP_INTERFACE | USB_TYPE_CLASS | USB_DIR_IN,
 964			cluster_id,
 965			snd_usb_ctrl_intf(chip),
 966			&hc_header, sizeof(hc_header));
 967	if (err < 0)
 968		return ERR_PTR(err);
 969	else if (err != sizeof(hc_header)) {
 970		dev_err(&dev->dev,
 971			"%u:%d : can't get High Capability descriptor\n",
 972			iface_no, altno);
 973		return ERR_PTR(-EIO);
 974	}
 975
 976	/*
 977	 * Second step: allocate needed amount of memory
 978	 * and request Cluster Descriptor
 979	 */
 980	wLength = le16_to_cpu(hc_header.wLength);
 981	cluster = kzalloc(wLength, GFP_KERNEL);
 982	if (!cluster)
 983		return ERR_PTR(-ENOMEM);
 984	err = snd_usb_ctl_msg(chip->dev,
 985			usb_rcvctrlpipe(chip->dev, 0),
 986			UAC3_CS_REQ_HIGH_CAPABILITY_DESCRIPTOR,
 987			USB_RECIP_INTERFACE | USB_TYPE_CLASS | USB_DIR_IN,
 988			cluster_id,
 989			snd_usb_ctrl_intf(chip),
 990			cluster, wLength);
 991	if (err < 0) {
 992		kfree(cluster);
 993		return ERR_PTR(err);
 994	} else if (err != wLength) {
 995		dev_err(&dev->dev,
 996			"%u:%d : can't get Cluster Descriptor\n",
 997			iface_no, altno);
 998		kfree(cluster);
 999		return ERR_PTR(-EIO);
1000	}
1001
1002	num_channels = cluster->bNrChannels;
1003	chmap = convert_chmap_v3(cluster);
1004	kfree(cluster);
1005
1006	/*
1007	 * lookup the terminal associated to this interface
1008	 * to extract the clock
1009	 */
1010	input_term = snd_usb_find_input_terminal_descriptor(chip->ctrl_intf,
1011							    as->bTerminalLink,
1012							    UAC_VERSION_3);
1013	if (input_term) {
1014		clock = input_term->bCSourceID;
1015		goto found_clock;
1016	}
1017
1018	output_term = snd_usb_find_output_terminal_descriptor(chip->ctrl_intf,
1019							      as->bTerminalLink,
1020							      UAC_VERSION_3);
1021	if (output_term) {
1022		clock = output_term->bCSourceID;
1023		goto found_clock;
1024	}
1025
1026	dev_err(&dev->dev, "%u:%d : bogus bTerminalLink %d\n",
1027			iface_no, altno, as->bTerminalLink);
1028	kfree(chmap);
1029	return NULL;
1030
1031found_clock:
1032	fp = audio_format_alloc_init(chip, alts, UAC_VERSION_3, iface_no,
1033				     altset_idx, altno, num_channels, clock);
1034	if (!fp) {
1035		kfree(chmap);
1036		return ERR_PTR(-ENOMEM);
1037	}
1038
1039	fp->chmap = chmap;
1040
1041	if (badd_profile >= UAC3_FUNCTION_SUBCLASS_GENERIC_IO) {
1042		fp->attributes = 0; /* No attributes */
1043
1044		fp->fmt_type = UAC_FORMAT_TYPE_I;
1045		fp->formats = badd_formats;
1046
1047		fp->nr_rates = 0;	/* SNDRV_PCM_RATE_CONTINUOUS */
1048		fp->rate_min = UAC3_BADD_SAMPLING_RATE;
1049		fp->rate_max = UAC3_BADD_SAMPLING_RATE;
1050		fp->rates = SNDRV_PCM_RATE_CONTINUOUS;
1051
1052		pd = kzalloc(sizeof(*pd), GFP_KERNEL);
1053		if (!pd) {
1054			audioformat_free(fp);
1055			return NULL;
1056		}
1057		pd->pd_id = (stream == SNDRV_PCM_STREAM_PLAYBACK) ?
1058					UAC3_BADD_PD_ID10 : UAC3_BADD_PD_ID11;
1059		pd->pd_d1d0_rec = UAC3_BADD_PD_RECOVER_D1D0;
1060		pd->pd_d2d0_rec = UAC3_BADD_PD_RECOVER_D2D0;
1061
1062	} else {
1063		fp->attributes = parse_uac_endpoint_attributes(chip, alts,
1064							       UAC_VERSION_3,
1065							       iface_no);
1066
1067		pd = snd_usb_find_power_domain(chip->ctrl_intf,
1068					       as->bTerminalLink);
1069
1070		/* ok, let's parse further... */
1071		if (snd_usb_parse_audio_format_v3(chip, fp, as, stream) < 0) {
1072			kfree(pd);
1073			audioformat_free(fp);
1074			return NULL;
1075		}
1076	}
1077
1078	if (pd)
1079		*pd_out = pd;
1080
1081	return fp;
1082}
1083
1084static int __snd_usb_parse_audio_interface(struct snd_usb_audio *chip,
1085					   int iface_no,
1086					   bool *has_non_pcm, bool non_pcm)
1087{
1088	struct usb_device *dev;
1089	struct usb_interface *iface;
1090	struct usb_host_interface *alts;
1091	struct usb_interface_descriptor *altsd;
1092	int i, altno, err, stream;
1093	struct audioformat *fp = NULL;
1094	struct snd_usb_power_domain *pd = NULL;
1095	int num, protocol;
1096
1097	dev = chip->dev;
1098
1099	/* parse the interface's altsettings */
1100	iface = usb_ifnum_to_if(dev, iface_no);
1101
1102	num = iface->num_altsetting;
1103
1104	/*
1105	 * Dallas DS4201 workaround: It presents 5 altsettings, but the last
1106	 * one misses syncpipe, and does not produce any sound.
1107	 */
1108	if (chip->usb_id == USB_ID(0x04fa, 0x4201))
1109		num = 4;
1110
1111	for (i = 0; i < num; i++) {
1112		alts = &iface->altsetting[i];
1113		altsd = get_iface_desc(alts);
1114		protocol = altsd->bInterfaceProtocol;
1115		/* skip invalid one */
1116		if (((altsd->bInterfaceClass != USB_CLASS_AUDIO ||
1117		      (altsd->bInterfaceSubClass != USB_SUBCLASS_AUDIOSTREAMING &&
1118		       altsd->bInterfaceSubClass != USB_SUBCLASS_VENDOR_SPEC)) &&
1119		     altsd->bInterfaceClass != USB_CLASS_VENDOR_SPEC) ||
1120		    altsd->bNumEndpoints < 1 ||
1121		    le16_to_cpu(get_endpoint(alts, 0)->wMaxPacketSize) == 0)
1122			continue;
1123		/* must be isochronous */
1124		if ((get_endpoint(alts, 0)->bmAttributes & USB_ENDPOINT_XFERTYPE_MASK) !=
1125		    USB_ENDPOINT_XFER_ISOC)
1126			continue;
1127		/* check direction */
1128		stream = (get_endpoint(alts, 0)->bEndpointAddress & USB_DIR_IN) ?
1129			SNDRV_PCM_STREAM_CAPTURE : SNDRV_PCM_STREAM_PLAYBACK;
1130		altno = altsd->bAlternateSetting;
1131
1132		if (snd_usb_apply_interface_quirk(chip, iface_no, altno))
1133			continue;
1134
1135		/*
1136		 * Roland audio streaming interfaces are marked with protocols
1137		 * 0/1/2, but are UAC 1 compatible.
1138		 */
1139		if (USB_ID_VENDOR(chip->usb_id) == 0x0582 &&
1140		    altsd->bInterfaceClass == USB_CLASS_VENDOR_SPEC &&
1141		    protocol <= 2)
1142			protocol = UAC_VERSION_1;
1143
1144		switch (protocol) {
1145		default:
1146			dev_dbg(&dev->dev, "%u:%d: unknown interface protocol %#02x, assuming v1\n",
1147				iface_no, altno, protocol);
1148			protocol = UAC_VERSION_1;
1149			fallthrough;
1150		case UAC_VERSION_1:
1151		case UAC_VERSION_2: {
1152			int bm_quirk = 0;
1153
1154			/*
1155			 * Blue Microphones workaround: The last altsetting is
1156			 * identical with the previous one, except for a larger
1157			 * packet size, but is actually a mislabeled two-channel
1158			 * setting; ignore it.
1159			 *
1160			 * Part 1: prepare quirk flag
1161			 */
1162			if (altno == 2 && num == 3 &&
1163			    fp && fp->altsetting == 1 && fp->channels == 1 &&
1164			    fp->formats == SNDRV_PCM_FMTBIT_S16_LE &&
1165			    protocol == UAC_VERSION_1 &&
1166			    le16_to_cpu(get_endpoint(alts, 0)->wMaxPacketSize) ==
1167							fp->maxpacksize * 2)
1168				bm_quirk = 1;
1169
1170			fp = snd_usb_get_audioformat_uac12(chip, alts, protocol,
1171							   iface_no, i, altno,
1172							   stream, bm_quirk);
1173			break;
1174		}
1175		case UAC_VERSION_3:
1176			fp = snd_usb_get_audioformat_uac3(chip, alts, &pd,
1177						iface_no, i, altno, stream);
1178			break;
1179		}
1180
1181		if (!fp)
1182			continue;
1183		else if (IS_ERR(fp))
1184			return PTR_ERR(fp);
1185
1186		if (fp->fmt_type != UAC_FORMAT_TYPE_I)
1187			*has_non_pcm = true;
1188		if ((fp->fmt_type == UAC_FORMAT_TYPE_I) == non_pcm) {
1189			audioformat_free(fp);
1190			kfree(pd);
1191			fp = NULL;
1192			pd = NULL;
1193			continue;
1194		}
1195
1196		snd_usb_audioformat_set_sync_ep(chip, fp);
1197
1198		dev_dbg(&dev->dev, "%u:%d: add audio endpoint %#x\n", iface_no, altno, fp->endpoint);
1199		if (protocol == UAC_VERSION_3)
1200			err = snd_usb_add_audio_stream_v3(chip, stream, fp, pd);
1201		else
1202			err = snd_usb_add_audio_stream(chip, stream, fp);
1203
1204		if (err < 0) {
1205			audioformat_free(fp);
1206			kfree(pd);
1207			return err;
1208		}
1209
1210		/* add endpoints */
1211		err = snd_usb_add_endpoint(chip, fp->endpoint,
1212					   SND_USB_ENDPOINT_TYPE_DATA);
1213		if (err < 0)
1214			return err;
1215
1216		if (fp->sync_ep) {
1217			err = snd_usb_add_endpoint(chip, fp->sync_ep,
1218						   fp->implicit_fb ?
1219						   SND_USB_ENDPOINT_TYPE_DATA :
1220						   SND_USB_ENDPOINT_TYPE_SYNC);
1221			if (err < 0)
1222				return err;
1223		}
1224
1225		/* try to set the interface... */
1226		usb_set_interface(chip->dev, iface_no, 0);
1227		snd_usb_init_pitch(chip, fp);
1228		snd_usb_init_sample_rate(chip, fp, fp->rate_max);
1229		usb_set_interface(chip->dev, iface_no, altno);
1230	}
1231	return 0;
1232}
1233
1234int snd_usb_parse_audio_interface(struct snd_usb_audio *chip, int iface_no)
1235{
1236	int err;
1237	bool has_non_pcm = false;
1238
1239	/* parse PCM formats */
1240	err = __snd_usb_parse_audio_interface(chip, iface_no, &has_non_pcm, false);
1241	if (err < 0)
1242		return err;
1243
1244	if (has_non_pcm) {
1245		/* parse non-PCM formats */
1246		err = __snd_usb_parse_audio_interface(chip, iface_no, &has_non_pcm, true);
1247		if (err < 0)
1248			return err;
1249	}
1250
1251	return 0;
1252}
1253