xref: /openbmc/linux/sound/usb/stream.c (revision d2ba09c1)
1 /*
2  *   This program is free software; you can redistribute it and/or modify
3  *   it under the terms of the GNU General Public License as published by
4  *   the Free Software Foundation; either version 2 of the License, or
5  *   (at your option) any later version.
6  *
7  *   This program is distributed in the hope that it will be useful,
8  *   but WITHOUT ANY WARRANTY; without even the implied warranty of
9  *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
10  *   GNU General Public License for more details.
11  *
12  *   You should have received a copy of the GNU General Public License
13  *   along with this program; if not, write to the Free Software
14  *   Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307 USA
15  */
16 
17 
18 #include <linux/init.h>
19 #include <linux/slab.h>
20 #include <linux/usb.h>
21 #include <linux/usb/audio.h>
22 #include <linux/usb/audio-v2.h>
23 #include <linux/usb/audio-v3.h>
24 
25 #include <sound/core.h>
26 #include <sound/pcm.h>
27 #include <sound/control.h>
28 #include <sound/tlv.h>
29 
30 #include "usbaudio.h"
31 #include "card.h"
32 #include "proc.h"
33 #include "quirks.h"
34 #include "endpoint.h"
35 #include "pcm.h"
36 #include "helper.h"
37 #include "format.h"
38 #include "clock.h"
39 #include "stream.h"
40 
41 /*
42  * free a substream
43  */
44 static void free_substream(struct snd_usb_substream *subs)
45 {
46 	struct audioformat *fp, *n;
47 
48 	if (!subs->num_formats)
49 		return; /* not initialized */
50 	list_for_each_entry_safe(fp, n, &subs->fmt_list, list) {
51 		kfree(fp->rate_table);
52 		kfree(fp->chmap);
53 		kfree(fp);
54 	}
55 	kfree(subs->rate_list.list);
56 }
57 
58 
59 /*
60  * free a usb stream instance
61  */
62 static void snd_usb_audio_stream_free(struct snd_usb_stream *stream)
63 {
64 	free_substream(&stream->substream[0]);
65 	free_substream(&stream->substream[1]);
66 	list_del(&stream->list);
67 	kfree(stream);
68 }
69 
70 static void snd_usb_audio_pcm_free(struct snd_pcm *pcm)
71 {
72 	struct snd_usb_stream *stream = pcm->private_data;
73 	if (stream) {
74 		stream->pcm = NULL;
75 		snd_usb_audio_stream_free(stream);
76 	}
77 }
78 
79 /*
80  * initialize the substream instance.
81  */
82 
83 static void snd_usb_init_substream(struct snd_usb_stream *as,
84 				   int stream,
85 				   struct audioformat *fp)
86 {
87 	struct snd_usb_substream *subs = &as->substream[stream];
88 
89 	INIT_LIST_HEAD(&subs->fmt_list);
90 	spin_lock_init(&subs->lock);
91 
92 	subs->stream = as;
93 	subs->direction = stream;
94 	subs->dev = as->chip->dev;
95 	subs->txfr_quirk = as->chip->txfr_quirk;
96 	subs->tx_length_quirk = as->chip->tx_length_quirk;
97 	subs->speed = snd_usb_get_speed(subs->dev);
98 	subs->pkt_offset_adj = 0;
99 
100 	snd_usb_set_pcm_ops(as->pcm, stream);
101 
102 	list_add_tail(&fp->list, &subs->fmt_list);
103 	subs->formats |= fp->formats;
104 	subs->num_formats++;
105 	subs->fmt_type = fp->fmt_type;
106 	subs->ep_num = fp->endpoint;
107 	if (fp->channels > subs->channels_max)
108 		subs->channels_max = fp->channels;
109 }
110 
111 /* kctl callbacks for usb-audio channel maps */
112 static int usb_chmap_ctl_info(struct snd_kcontrol *kcontrol,
113 			      struct snd_ctl_elem_info *uinfo)
114 {
115 	struct snd_pcm_chmap *info = snd_kcontrol_chip(kcontrol);
116 	struct snd_usb_substream *subs = info->private_data;
117 
118 	uinfo->type = SNDRV_CTL_ELEM_TYPE_INTEGER;
119 	uinfo->count = subs->channels_max;
120 	uinfo->value.integer.min = 0;
121 	uinfo->value.integer.max = SNDRV_CHMAP_LAST;
122 	return 0;
123 }
124 
125 /* check whether a duplicated entry exists in the audiofmt list */
126 static bool have_dup_chmap(struct snd_usb_substream *subs,
127 			   struct audioformat *fp)
128 {
129 	struct audioformat *prev = fp;
130 
131 	list_for_each_entry_continue_reverse(prev, &subs->fmt_list, list) {
132 		if (prev->chmap &&
133 		    !memcmp(prev->chmap, fp->chmap, sizeof(*fp->chmap)))
134 			return true;
135 	}
136 	return false;
137 }
138 
139 static int usb_chmap_ctl_tlv(struct snd_kcontrol *kcontrol, int op_flag,
140 			     unsigned int size, unsigned int __user *tlv)
141 {
142 	struct snd_pcm_chmap *info = snd_kcontrol_chip(kcontrol);
143 	struct snd_usb_substream *subs = info->private_data;
144 	struct audioformat *fp;
145 	unsigned int __user *dst;
146 	int count = 0;
147 
148 	if (size < 8)
149 		return -ENOMEM;
150 	if (put_user(SNDRV_CTL_TLVT_CONTAINER, tlv))
151 		return -EFAULT;
152 	size -= 8;
153 	dst = tlv + 2;
154 	list_for_each_entry(fp, &subs->fmt_list, list) {
155 		int i, ch_bytes;
156 
157 		if (!fp->chmap)
158 			continue;
159 		if (have_dup_chmap(subs, fp))
160 			continue;
161 		/* copy the entry */
162 		ch_bytes = fp->chmap->channels * 4;
163 		if (size < 8 + ch_bytes)
164 			return -ENOMEM;
165 		if (put_user(SNDRV_CTL_TLVT_CHMAP_FIXED, dst) ||
166 		    put_user(ch_bytes, dst + 1))
167 			return -EFAULT;
168 		dst += 2;
169 		for (i = 0; i < fp->chmap->channels; i++, dst++) {
170 			if (put_user(fp->chmap->map[i], dst))
171 				return -EFAULT;
172 		}
173 
174 		count += 8 + ch_bytes;
175 		size -= 8 + ch_bytes;
176 	}
177 	if (put_user(count, tlv + 1))
178 		return -EFAULT;
179 	return 0;
180 }
181 
182 static int usb_chmap_ctl_get(struct snd_kcontrol *kcontrol,
183 			     struct snd_ctl_elem_value *ucontrol)
184 {
185 	struct snd_pcm_chmap *info = snd_kcontrol_chip(kcontrol);
186 	struct snd_usb_substream *subs = info->private_data;
187 	struct snd_pcm_chmap_elem *chmap = NULL;
188 	int i;
189 
190 	memset(ucontrol->value.integer.value, 0,
191 	       sizeof(ucontrol->value.integer.value));
192 	if (subs->cur_audiofmt)
193 		chmap = subs->cur_audiofmt->chmap;
194 	if (chmap) {
195 		for (i = 0; i < chmap->channels; i++)
196 			ucontrol->value.integer.value[i] = chmap->map[i];
197 	}
198 	return 0;
199 }
200 
201 /* create a chmap kctl assigned to the given USB substream */
202 static int add_chmap(struct snd_pcm *pcm, int stream,
203 		     struct snd_usb_substream *subs)
204 {
205 	struct audioformat *fp;
206 	struct snd_pcm_chmap *chmap;
207 	struct snd_kcontrol *kctl;
208 	int err;
209 
210 	list_for_each_entry(fp, &subs->fmt_list, list)
211 		if (fp->chmap)
212 			goto ok;
213 	/* no chmap is found */
214 	return 0;
215 
216  ok:
217 	err = snd_pcm_add_chmap_ctls(pcm, stream, NULL, 0, 0, &chmap);
218 	if (err < 0)
219 		return err;
220 
221 	/* override handlers */
222 	chmap->private_data = subs;
223 	kctl = chmap->kctl;
224 	kctl->info = usb_chmap_ctl_info;
225 	kctl->get = usb_chmap_ctl_get;
226 	kctl->tlv.c = usb_chmap_ctl_tlv;
227 
228 	return 0;
229 }
230 
231 /* convert from USB ChannelConfig bits to ALSA chmap element */
232 static struct snd_pcm_chmap_elem *convert_chmap(int channels, unsigned int bits,
233 						int protocol)
234 {
235 	static unsigned int uac1_maps[] = {
236 		SNDRV_CHMAP_FL,		/* left front */
237 		SNDRV_CHMAP_FR,		/* right front */
238 		SNDRV_CHMAP_FC,		/* center front */
239 		SNDRV_CHMAP_LFE,	/* LFE */
240 		SNDRV_CHMAP_SL,		/* left surround */
241 		SNDRV_CHMAP_SR,		/* right surround */
242 		SNDRV_CHMAP_FLC,	/* left of center */
243 		SNDRV_CHMAP_FRC,	/* right of center */
244 		SNDRV_CHMAP_RC,		/* surround */
245 		SNDRV_CHMAP_SL,		/* side left */
246 		SNDRV_CHMAP_SR,		/* side right */
247 		SNDRV_CHMAP_TC,		/* top */
248 		0 /* terminator */
249 	};
250 	static unsigned int uac2_maps[] = {
251 		SNDRV_CHMAP_FL,		/* front left */
252 		SNDRV_CHMAP_FR,		/* front right */
253 		SNDRV_CHMAP_FC,		/* front center */
254 		SNDRV_CHMAP_LFE,	/* LFE */
255 		SNDRV_CHMAP_RL,		/* back left */
256 		SNDRV_CHMAP_RR,		/* back right */
257 		SNDRV_CHMAP_FLC,	/* front left of center */
258 		SNDRV_CHMAP_FRC,	/* front right of center */
259 		SNDRV_CHMAP_RC,		/* back center */
260 		SNDRV_CHMAP_SL,		/* side left */
261 		SNDRV_CHMAP_SR,		/* side right */
262 		SNDRV_CHMAP_TC,		/* top center */
263 		SNDRV_CHMAP_TFL,	/* top front left */
264 		SNDRV_CHMAP_TFC,	/* top front center */
265 		SNDRV_CHMAP_TFR,	/* top front right */
266 		SNDRV_CHMAP_TRL,	/* top back left */
267 		SNDRV_CHMAP_TRC,	/* top back center */
268 		SNDRV_CHMAP_TRR,	/* top back right */
269 		SNDRV_CHMAP_TFLC,	/* top front left of center */
270 		SNDRV_CHMAP_TFRC,	/* top front right of center */
271 		SNDRV_CHMAP_LLFE,	/* left LFE */
272 		SNDRV_CHMAP_RLFE,	/* right LFE */
273 		SNDRV_CHMAP_TSL,	/* top side left */
274 		SNDRV_CHMAP_TSR,	/* top side right */
275 		SNDRV_CHMAP_BC,		/* bottom center */
276 		SNDRV_CHMAP_RLC,	/* back left of center */
277 		SNDRV_CHMAP_RRC,	/* back right of center */
278 		0 /* terminator */
279 	};
280 	struct snd_pcm_chmap_elem *chmap;
281 	const unsigned int *maps;
282 	int c;
283 
284 	if (channels > ARRAY_SIZE(chmap->map))
285 		return NULL;
286 
287 	chmap = kzalloc(sizeof(*chmap), GFP_KERNEL);
288 	if (!chmap)
289 		return NULL;
290 
291 	maps = protocol == UAC_VERSION_2 ? uac2_maps : uac1_maps;
292 	chmap->channels = channels;
293 	c = 0;
294 
295 	if (bits) {
296 		for (; bits && *maps; maps++, bits >>= 1)
297 			if (bits & 1)
298 				chmap->map[c++] = *maps;
299 	} else {
300 		/* If we're missing wChannelConfig, then guess something
301 		    to make sure the channel map is not skipped entirely */
302 		if (channels == 1)
303 			chmap->map[c++] = SNDRV_CHMAP_MONO;
304 		else
305 			for (; c < channels && *maps; maps++)
306 				chmap->map[c++] = *maps;
307 	}
308 
309 	for (; c < channels; c++)
310 		chmap->map[c] = SNDRV_CHMAP_UNKNOWN;
311 
312 	return chmap;
313 }
314 
315 /* UAC3 device stores channels information in Cluster Descriptors */
316 static struct
317 snd_pcm_chmap_elem *convert_chmap_v3(struct uac3_cluster_header_descriptor
318 								*cluster)
319 {
320 	unsigned int channels = cluster->bNrChannels;
321 	struct snd_pcm_chmap_elem *chmap;
322 	void *p = cluster;
323 	int len, c;
324 
325 	if (channels > ARRAY_SIZE(chmap->map))
326 		return NULL;
327 
328 	chmap = kzalloc(sizeof(*chmap), GFP_KERNEL);
329 	if (!chmap)
330 		return NULL;
331 
332 	len = le16_to_cpu(cluster->wLength);
333 	c = 0;
334 	p += sizeof(struct uac3_cluster_header_descriptor);
335 
336 	while (((p - (void *)cluster) < len) && (c < channels)) {
337 		struct uac3_cluster_segment_descriptor *cs_desc = p;
338 		u16 cs_len;
339 		u8 cs_type;
340 
341 		cs_len = le16_to_cpu(cs_desc->wLength);
342 		cs_type = cs_desc->bSegmentType;
343 
344 		if (cs_type == UAC3_CHANNEL_INFORMATION) {
345 			struct uac3_cluster_information_segment_descriptor *is = p;
346 			unsigned char map;
347 
348 			/*
349 			 * TODO: this conversion is not complete, update it
350 			 * after adding UAC3 values to asound.h
351 			 */
352 			switch (is->bChRelationship) {
353 			case UAC3_CH_MONO:
354 				map = SNDRV_CHMAP_MONO;
355 				break;
356 			case UAC3_CH_LEFT:
357 			case UAC3_CH_FRONT_LEFT:
358 			case UAC3_CH_HEADPHONE_LEFT:
359 				map = SNDRV_CHMAP_FL;
360 				break;
361 			case UAC3_CH_RIGHT:
362 			case UAC3_CH_FRONT_RIGHT:
363 			case UAC3_CH_HEADPHONE_RIGHT:
364 				map = SNDRV_CHMAP_FR;
365 				break;
366 			case UAC3_CH_FRONT_CENTER:
367 				map = SNDRV_CHMAP_FC;
368 				break;
369 			case UAC3_CH_FRONT_LEFT_OF_CENTER:
370 				map = SNDRV_CHMAP_FLC;
371 				break;
372 			case UAC3_CH_FRONT_RIGHT_OF_CENTER:
373 				map = SNDRV_CHMAP_FRC;
374 				break;
375 			case UAC3_CH_SIDE_LEFT:
376 				map = SNDRV_CHMAP_SL;
377 				break;
378 			case UAC3_CH_SIDE_RIGHT:
379 				map = SNDRV_CHMAP_SR;
380 				break;
381 			case UAC3_CH_BACK_LEFT:
382 				map = SNDRV_CHMAP_RL;
383 				break;
384 			case UAC3_CH_BACK_RIGHT:
385 				map = SNDRV_CHMAP_RR;
386 				break;
387 			case UAC3_CH_BACK_CENTER:
388 				map = SNDRV_CHMAP_RC;
389 				break;
390 			case UAC3_CH_BACK_LEFT_OF_CENTER:
391 				map = SNDRV_CHMAP_RLC;
392 				break;
393 			case UAC3_CH_BACK_RIGHT_OF_CENTER:
394 				map = SNDRV_CHMAP_RRC;
395 				break;
396 			case UAC3_CH_TOP_CENTER:
397 				map = SNDRV_CHMAP_TC;
398 				break;
399 			case UAC3_CH_TOP_FRONT_LEFT:
400 				map = SNDRV_CHMAP_TFL;
401 				break;
402 			case UAC3_CH_TOP_FRONT_RIGHT:
403 				map = SNDRV_CHMAP_TFR;
404 				break;
405 			case UAC3_CH_TOP_FRONT_CENTER:
406 				map = SNDRV_CHMAP_TFC;
407 				break;
408 			case UAC3_CH_TOP_FRONT_LOC:
409 				map = SNDRV_CHMAP_TFLC;
410 				break;
411 			case UAC3_CH_TOP_FRONT_ROC:
412 				map = SNDRV_CHMAP_TFRC;
413 				break;
414 			case UAC3_CH_TOP_SIDE_LEFT:
415 				map = SNDRV_CHMAP_TSL;
416 				break;
417 			case UAC3_CH_TOP_SIDE_RIGHT:
418 				map = SNDRV_CHMAP_TSR;
419 				break;
420 			case UAC3_CH_TOP_BACK_LEFT:
421 				map = SNDRV_CHMAP_TRL;
422 				break;
423 			case UAC3_CH_TOP_BACK_RIGHT:
424 				map = SNDRV_CHMAP_TRR;
425 				break;
426 			case UAC3_CH_TOP_BACK_CENTER:
427 				map = SNDRV_CHMAP_TRC;
428 				break;
429 			case UAC3_CH_BOTTOM_CENTER:
430 				map = SNDRV_CHMAP_BC;
431 				break;
432 			case UAC3_CH_LOW_FREQUENCY_EFFECTS:
433 				map = SNDRV_CHMAP_LFE;
434 				break;
435 			case UAC3_CH_LFE_LEFT:
436 				map = SNDRV_CHMAP_LLFE;
437 				break;
438 			case UAC3_CH_LFE_RIGHT:
439 				map = SNDRV_CHMAP_RLFE;
440 				break;
441 			case UAC3_CH_RELATIONSHIP_UNDEFINED:
442 			default:
443 				map = SNDRV_CHMAP_UNKNOWN;
444 				break;
445 			}
446 			chmap->map[c++] = map;
447 		}
448 		p += cs_len;
449 	}
450 
451 	if (channels < c)
452 		pr_err("%s: channel number mismatch\n", __func__);
453 
454 	chmap->channels = channels;
455 
456 	for (; c < channels; c++)
457 		chmap->map[c] = SNDRV_CHMAP_UNKNOWN;
458 
459 	return chmap;
460 }
461 
462 /*
463  * add this endpoint to the chip instance.
464  * if a stream with the same endpoint already exists, append to it.
465  * if not, create a new pcm stream. note, fp is added to the substream
466  * fmt_list and will be freed on the chip instance release. do not free
467  * fp or do remove it from the substream fmt_list to avoid double-free.
468  */
469 int snd_usb_add_audio_stream(struct snd_usb_audio *chip,
470 			     int stream,
471 			     struct audioformat *fp)
472 {
473 	struct snd_usb_stream *as;
474 	struct snd_usb_substream *subs;
475 	struct snd_pcm *pcm;
476 	int err;
477 
478 	list_for_each_entry(as, &chip->pcm_list, list) {
479 		if (as->fmt_type != fp->fmt_type)
480 			continue;
481 		subs = &as->substream[stream];
482 		if (subs->ep_num == fp->endpoint) {
483 			list_add_tail(&fp->list, &subs->fmt_list);
484 			subs->num_formats++;
485 			subs->formats |= fp->formats;
486 			return 0;
487 		}
488 	}
489 	/* look for an empty stream */
490 	list_for_each_entry(as, &chip->pcm_list, list) {
491 		if (as->fmt_type != fp->fmt_type)
492 			continue;
493 		subs = &as->substream[stream];
494 		if (subs->ep_num)
495 			continue;
496 		err = snd_pcm_new_stream(as->pcm, stream, 1);
497 		if (err < 0)
498 			return err;
499 		snd_usb_init_substream(as, stream, fp);
500 		return add_chmap(as->pcm, stream, subs);
501 	}
502 
503 	/* create a new pcm */
504 	as = kzalloc(sizeof(*as), GFP_KERNEL);
505 	if (!as)
506 		return -ENOMEM;
507 	as->pcm_index = chip->pcm_devs;
508 	as->chip = chip;
509 	as->fmt_type = fp->fmt_type;
510 	err = snd_pcm_new(chip->card, "USB Audio", chip->pcm_devs,
511 			  stream == SNDRV_PCM_STREAM_PLAYBACK ? 1 : 0,
512 			  stream == SNDRV_PCM_STREAM_PLAYBACK ? 0 : 1,
513 			  &pcm);
514 	if (err < 0) {
515 		kfree(as);
516 		return err;
517 	}
518 	as->pcm = pcm;
519 	pcm->private_data = as;
520 	pcm->private_free = snd_usb_audio_pcm_free;
521 	pcm->info_flags = 0;
522 	if (chip->pcm_devs > 0)
523 		sprintf(pcm->name, "USB Audio #%d", chip->pcm_devs);
524 	else
525 		strcpy(pcm->name, "USB Audio");
526 
527 	snd_usb_init_substream(as, stream, fp);
528 
529 	/*
530 	 * Keep using head insertion for M-Audio Audiophile USB (tm) which has a
531 	 * fix to swap capture stream order in conf/cards/USB-audio.conf
532 	 */
533 	if (chip->usb_id == USB_ID(0x0763, 0x2003))
534 		list_add(&as->list, &chip->pcm_list);
535 	else
536 		list_add_tail(&as->list, &chip->pcm_list);
537 
538 	chip->pcm_devs++;
539 
540 	snd_usb_proc_pcm_format_add(as);
541 
542 	return add_chmap(pcm, stream, &as->substream[stream]);
543 }
544 
545 static int parse_uac_endpoint_attributes(struct snd_usb_audio *chip,
546 					 struct usb_host_interface *alts,
547 					 int protocol, int iface_no)
548 {
549 	/* parsed with a v1 header here. that's ok as we only look at the
550 	 * header first which is the same for both versions */
551 	struct uac_iso_endpoint_descriptor *csep;
552 	struct usb_interface_descriptor *altsd = get_iface_desc(alts);
553 	int attributes = 0;
554 
555 	csep = snd_usb_find_desc(alts->endpoint[0].extra, alts->endpoint[0].extralen, NULL, USB_DT_CS_ENDPOINT);
556 
557 	/* Creamware Noah has this descriptor after the 2nd endpoint */
558 	if (!csep && altsd->bNumEndpoints >= 2)
559 		csep = snd_usb_find_desc(alts->endpoint[1].extra, alts->endpoint[1].extralen, NULL, USB_DT_CS_ENDPOINT);
560 
561 	/*
562 	 * If we can't locate the USB_DT_CS_ENDPOINT descriptor in the extra
563 	 * bytes after the first endpoint, go search the entire interface.
564 	 * Some devices have it directly *before* the standard endpoint.
565 	 */
566 	if (!csep)
567 		csep = snd_usb_find_desc(alts->extra, alts->extralen, NULL, USB_DT_CS_ENDPOINT);
568 
569 	if (!csep || csep->bLength < 7 ||
570 	    csep->bDescriptorSubtype != UAC_EP_GENERAL) {
571 		usb_audio_warn(chip,
572 			       "%u:%d : no or invalid class specific endpoint descriptor\n",
573 			       iface_no, altsd->bAlternateSetting);
574 		return 0;
575 	}
576 
577 	if (protocol == UAC_VERSION_1) {
578 		attributes = csep->bmAttributes;
579 	} else if (protocol == UAC_VERSION_2) {
580 		struct uac2_iso_endpoint_descriptor *csep2 =
581 			(struct uac2_iso_endpoint_descriptor *) csep;
582 
583 		attributes = csep->bmAttributes & UAC_EP_CS_ATTR_FILL_MAX;
584 
585 		/* emulate the endpoint attributes of a v1 device */
586 		if (csep2->bmControls & UAC2_CONTROL_PITCH)
587 			attributes |= UAC_EP_CS_ATTR_PITCH_CONTROL;
588 	} else { /* UAC_VERSION_3 */
589 		struct uac3_iso_endpoint_descriptor *csep3 =
590 			(struct uac3_iso_endpoint_descriptor *) csep;
591 
592 		/* emulate the endpoint attributes of a v1 device */
593 		if (le32_to_cpu(csep3->bmControls) & UAC2_CONTROL_PITCH)
594 			attributes |= UAC_EP_CS_ATTR_PITCH_CONTROL;
595 	}
596 
597 	return attributes;
598 }
599 
600 /* find an input terminal descriptor (either UAC1 or UAC2) with the given
601  * terminal id
602  */
603 static void *
604 snd_usb_find_input_terminal_descriptor(struct usb_host_interface *ctrl_iface,
605 					       int terminal_id)
606 {
607 	struct uac2_input_terminal_descriptor *term = NULL;
608 
609 	while ((term = snd_usb_find_csint_desc(ctrl_iface->extra,
610 					       ctrl_iface->extralen,
611 					       term, UAC_INPUT_TERMINAL))) {
612 		if (term->bTerminalID == terminal_id)
613 			return term;
614 	}
615 
616 	return NULL;
617 }
618 
619 static void *
620 snd_usb_find_output_terminal_descriptor(struct usb_host_interface *ctrl_iface,
621 					int terminal_id)
622 {
623 	/* OK to use with both UAC2 and UAC3 */
624 	struct uac2_output_terminal_descriptor *term = NULL;
625 
626 	while ((term = snd_usb_find_csint_desc(ctrl_iface->extra,
627 					       ctrl_iface->extralen,
628 					       term, UAC_OUTPUT_TERMINAL))) {
629 		if (term->bTerminalID == terminal_id)
630 			return term;
631 	}
632 
633 	return NULL;
634 }
635 
636 int snd_usb_parse_audio_interface(struct snd_usb_audio *chip, int iface_no)
637 {
638 	struct usb_device *dev;
639 	struct usb_interface *iface;
640 	struct usb_host_interface *alts;
641 	struct usb_interface_descriptor *altsd;
642 	int i, altno, err, stream;
643 	u64 format = 0;
644 	unsigned int num_channels = 0;
645 	struct audioformat *fp = NULL;
646 	int num, protocol, clock = 0;
647 	struct uac_format_type_i_continuous_descriptor *fmt = NULL;
648 	struct snd_pcm_chmap_elem *chmap_v3 = NULL;
649 	unsigned int chconfig;
650 
651 	dev = chip->dev;
652 
653 	/* parse the interface's altsettings */
654 	iface = usb_ifnum_to_if(dev, iface_no);
655 
656 	num = iface->num_altsetting;
657 
658 	/*
659 	 * Dallas DS4201 workaround: It presents 5 altsettings, but the last
660 	 * one misses syncpipe, and does not produce any sound.
661 	 */
662 	if (chip->usb_id == USB_ID(0x04fa, 0x4201))
663 		num = 4;
664 
665 	for (i = 0; i < num; i++) {
666 		alts = &iface->altsetting[i];
667 		altsd = get_iface_desc(alts);
668 		protocol = altsd->bInterfaceProtocol;
669 		/* skip invalid one */
670 		if (((altsd->bInterfaceClass != USB_CLASS_AUDIO ||
671 		      (altsd->bInterfaceSubClass != USB_SUBCLASS_AUDIOSTREAMING &&
672 		       altsd->bInterfaceSubClass != USB_SUBCLASS_VENDOR_SPEC)) &&
673 		     altsd->bInterfaceClass != USB_CLASS_VENDOR_SPEC) ||
674 		    altsd->bNumEndpoints < 1 ||
675 		    le16_to_cpu(get_endpoint(alts, 0)->wMaxPacketSize) == 0)
676 			continue;
677 		/* must be isochronous */
678 		if ((get_endpoint(alts, 0)->bmAttributes & USB_ENDPOINT_XFERTYPE_MASK) !=
679 		    USB_ENDPOINT_XFER_ISOC)
680 			continue;
681 		/* check direction */
682 		stream = (get_endpoint(alts, 0)->bEndpointAddress & USB_DIR_IN) ?
683 			SNDRV_PCM_STREAM_CAPTURE : SNDRV_PCM_STREAM_PLAYBACK;
684 		altno = altsd->bAlternateSetting;
685 
686 		if (snd_usb_apply_interface_quirk(chip, iface_no, altno))
687 			continue;
688 
689 		/*
690 		 * Roland audio streaming interfaces are marked with protocols
691 		 * 0/1/2, but are UAC 1 compatible.
692 		 */
693 		if (USB_ID_VENDOR(chip->usb_id) == 0x0582 &&
694 		    altsd->bInterfaceClass == USB_CLASS_VENDOR_SPEC &&
695 		    protocol <= 2)
696 			protocol = UAC_VERSION_1;
697 
698 		chconfig = 0;
699 		/* get audio formats */
700 		switch (protocol) {
701 		default:
702 			dev_dbg(&dev->dev, "%u:%d: unknown interface protocol %#02x, assuming v1\n",
703 				iface_no, altno, protocol);
704 			protocol = UAC_VERSION_1;
705 			/* fall through */
706 
707 		case UAC_VERSION_1: {
708 			struct uac1_as_header_descriptor *as =
709 				snd_usb_find_csint_desc(alts->extra, alts->extralen, NULL, UAC_AS_GENERAL);
710 			struct uac_input_terminal_descriptor *iterm;
711 
712 			if (!as) {
713 				dev_err(&dev->dev,
714 					"%u:%d : UAC_AS_GENERAL descriptor not found\n",
715 					iface_no, altno);
716 				continue;
717 			}
718 
719 			if (as->bLength < sizeof(*as)) {
720 				dev_err(&dev->dev,
721 					"%u:%d : invalid UAC_AS_GENERAL desc\n",
722 					iface_no, altno);
723 				continue;
724 			}
725 
726 			format = le16_to_cpu(as->wFormatTag); /* remember the format value */
727 
728 			iterm = snd_usb_find_input_terminal_descriptor(chip->ctrl_intf,
729 								       as->bTerminalLink);
730 			if (iterm) {
731 				num_channels = iterm->bNrChannels;
732 				chconfig = le16_to_cpu(iterm->wChannelConfig);
733 			}
734 
735 			break;
736 		}
737 
738 		case UAC_VERSION_2: {
739 			struct uac2_input_terminal_descriptor *input_term;
740 			struct uac2_output_terminal_descriptor *output_term;
741 			struct uac2_as_header_descriptor *as =
742 				snd_usb_find_csint_desc(alts->extra, alts->extralen, NULL, UAC_AS_GENERAL);
743 
744 			if (!as) {
745 				dev_err(&dev->dev,
746 					"%u:%d : UAC_AS_GENERAL descriptor not found\n",
747 					iface_no, altno);
748 				continue;
749 			}
750 
751 			if (as->bLength < sizeof(*as)) {
752 				dev_err(&dev->dev,
753 					"%u:%d : invalid UAC_AS_GENERAL desc\n",
754 					iface_no, altno);
755 				continue;
756 			}
757 
758 			num_channels = as->bNrChannels;
759 			format = le32_to_cpu(as->bmFormats);
760 			chconfig = le32_to_cpu(as->bmChannelConfig);
761 
762 			/* lookup the terminal associated to this interface
763 			 * to extract the clock */
764 			input_term = snd_usb_find_input_terminal_descriptor(chip->ctrl_intf,
765 									    as->bTerminalLink);
766 			if (input_term) {
767 				clock = input_term->bCSourceID;
768 				if (!chconfig && (num_channels == input_term->bNrChannels))
769 					chconfig = le32_to_cpu(input_term->bmChannelConfig);
770 				break;
771 			}
772 
773 			output_term = snd_usb_find_output_terminal_descriptor(chip->ctrl_intf,
774 									      as->bTerminalLink);
775 			if (output_term) {
776 				clock = output_term->bCSourceID;
777 				break;
778 			}
779 
780 			dev_err(&dev->dev,
781 				"%u:%d : bogus bTerminalLink %d\n",
782 				iface_no, altno, as->bTerminalLink);
783 			continue;
784 		}
785 
786 		case UAC_VERSION_3: {
787 			struct uac3_input_terminal_descriptor *input_term;
788 			struct uac3_output_terminal_descriptor *output_term;
789 			struct uac3_as_header_descriptor *as;
790 			struct uac3_cluster_header_descriptor *cluster;
791 			struct uac3_hc_descriptor_header hc_header;
792 			u16 cluster_id, wLength;
793 
794 			as = snd_usb_find_csint_desc(alts->extra,
795 							alts->extralen,
796 							NULL, UAC_AS_GENERAL);
797 
798 			if (!as) {
799 				dev_err(&dev->dev,
800 					"%u:%d : UAC_AS_GENERAL descriptor not found\n",
801 					iface_no, altno);
802 				continue;
803 			}
804 
805 			if (as->bLength < sizeof(*as)) {
806 				dev_err(&dev->dev,
807 					"%u:%d : invalid UAC_AS_GENERAL desc\n",
808 					iface_no, altno);
809 				continue;
810 			}
811 
812 			cluster_id = le16_to_cpu(as->wClusterDescrID);
813 			if (!cluster_id) {
814 				dev_err(&dev->dev,
815 					"%u:%d : no cluster descriptor\n",
816 					iface_no, altno);
817 				continue;
818 			}
819 
820 			/*
821 			 * Get number of channels and channel map through
822 			 * High Capability Cluster Descriptor
823 			 *
824 			 * First step: get High Capability header and
825 			 * read size of Cluster Descriptor
826 			 */
827 			err = snd_usb_ctl_msg(chip->dev,
828 					usb_rcvctrlpipe(chip->dev, 0),
829 					UAC3_CS_REQ_HIGH_CAPABILITY_DESCRIPTOR,
830 					USB_RECIP_INTERFACE | USB_TYPE_CLASS | USB_DIR_IN,
831 					cluster_id,
832 					snd_usb_ctrl_intf(chip),
833 					&hc_header, sizeof(hc_header));
834 			if (err < 0)
835 				return err;
836 			else if (err != sizeof(hc_header)) {
837 				dev_err(&dev->dev,
838 					"%u:%d : can't get High Capability descriptor\n",
839 					iface_no, altno);
840 				return -EIO;
841 			}
842 
843 			/*
844 			 * Second step: allocate needed amount of memory
845 			 * and request Cluster Descriptor
846 			 */
847 			wLength = le16_to_cpu(hc_header.wLength);
848 			cluster = kzalloc(wLength, GFP_KERNEL);
849 			if (!cluster)
850 				return -ENOMEM;
851 			err = snd_usb_ctl_msg(chip->dev,
852 					usb_rcvctrlpipe(chip->dev, 0),
853 					UAC3_CS_REQ_HIGH_CAPABILITY_DESCRIPTOR,
854 					USB_RECIP_INTERFACE | USB_TYPE_CLASS | USB_DIR_IN,
855 					cluster_id,
856 					snd_usb_ctrl_intf(chip),
857 					cluster, wLength);
858 			if (err < 0) {
859 				kfree(cluster);
860 				return err;
861 			} else if (err != wLength) {
862 				dev_err(&dev->dev,
863 					"%u:%d : can't get Cluster Descriptor\n",
864 					iface_no, altno);
865 				kfree(cluster);
866 				return -EIO;
867 			}
868 
869 			num_channels = cluster->bNrChannels;
870 			chmap_v3 = convert_chmap_v3(cluster);
871 
872 			kfree(cluster);
873 
874 			format = le64_to_cpu(as->bmFormats);
875 
876 			/* lookup the terminal associated to this interface
877 			 * to extract the clock */
878 			input_term = snd_usb_find_input_terminal_descriptor(
879 							chip->ctrl_intf,
880 							as->bTerminalLink);
881 
882 			if (input_term) {
883 				clock = input_term->bCSourceID;
884 				break;
885 			}
886 
887 			output_term = snd_usb_find_output_terminal_descriptor(chip->ctrl_intf,
888 									      as->bTerminalLink);
889 			if (output_term) {
890 				clock = output_term->bCSourceID;
891 				break;
892 			}
893 
894 			dev_err(&dev->dev,
895 				"%u:%d : bogus bTerminalLink %d\n",
896 				iface_no, altno, as->bTerminalLink);
897 			continue;
898 		}
899 		}
900 
901 		if (protocol == UAC_VERSION_1 || protocol == UAC_VERSION_2) {
902 			/* get format type */
903 			fmt = snd_usb_find_csint_desc(alts->extra,
904 						      alts->extralen,
905 						      NULL, UAC_FORMAT_TYPE);
906 			if (!fmt) {
907 				dev_err(&dev->dev,
908 					"%u:%d : no UAC_FORMAT_TYPE desc\n",
909 					iface_no, altno);
910 				continue;
911 			}
912 			if (((protocol == UAC_VERSION_1) && (fmt->bLength < 8))
913 					|| ((protocol == UAC_VERSION_2) &&
914 							(fmt->bLength < 6))) {
915 				dev_err(&dev->dev,
916 					"%u:%d : invalid UAC_FORMAT_TYPE desc\n",
917 					iface_no, altno);
918 				continue;
919 			}
920 
921 			/*
922 			 * Blue Microphones workaround: The last altsetting is
923 			 * identical with the previous one, except for a larger
924 			 * packet size, but is actually a mislabeled two-channel
925 			 * setting; ignore it.
926 			 */
927 			if (fmt->bNrChannels == 1 &&
928 			    fmt->bSubframeSize == 2 &&
929 			    altno == 2 && num == 3 &&
930 			    fp && fp->altsetting == 1 && fp->channels == 1 &&
931 			    fp->formats == SNDRV_PCM_FMTBIT_S16_LE &&
932 			    protocol == UAC_VERSION_1 &&
933 			    le16_to_cpu(get_endpoint(alts, 0)->wMaxPacketSize) ==
934 							fp->maxpacksize * 2)
935 				continue;
936 		}
937 
938 		fp = kzalloc(sizeof(*fp), GFP_KERNEL);
939 		if (!fp)
940 			return -ENOMEM;
941 
942 		fp->iface = iface_no;
943 		fp->altsetting = altno;
944 		fp->altset_idx = i;
945 		fp->endpoint = get_endpoint(alts, 0)->bEndpointAddress;
946 		fp->ep_attr = get_endpoint(alts, 0)->bmAttributes;
947 		fp->datainterval = snd_usb_parse_datainterval(chip, alts);
948 		fp->protocol = protocol;
949 		fp->maxpacksize = le16_to_cpu(get_endpoint(alts, 0)->wMaxPacketSize);
950 		fp->channels = num_channels;
951 		if (snd_usb_get_speed(dev) == USB_SPEED_HIGH)
952 			fp->maxpacksize = (((fp->maxpacksize >> 11) & 3) + 1)
953 					* (fp->maxpacksize & 0x7ff);
954 		fp->attributes = parse_uac_endpoint_attributes(chip, alts, protocol, iface_no);
955 		fp->clock = clock;
956 		INIT_LIST_HEAD(&fp->list);
957 
958 		/* some quirks for attributes here */
959 		snd_usb_audioformat_attributes_quirk(chip, fp, stream);
960 
961 		/* ok, let's parse further... */
962 		if (protocol == UAC_VERSION_1 || protocol == UAC_VERSION_2) {
963 			if (snd_usb_parse_audio_format(chip, fp, format,
964 							fmt, stream) < 0) {
965 				kfree(fp->rate_table);
966 				kfree(fp);
967 				fp = NULL;
968 				continue;
969 			}
970 		} else {
971 			struct uac3_as_header_descriptor *as;
972 
973 			as = snd_usb_find_csint_desc(alts->extra,
974 						     alts->extralen,
975 						     NULL, UAC_AS_GENERAL);
976 
977 			if (snd_usb_parse_audio_format_v3(chip, fp, as,
978 								stream) < 0) {
979 				kfree(fp->rate_table);
980 				kfree(fp);
981 				fp = NULL;
982 				continue;
983 			}
984 		}
985 
986 		/* Create chmap */
987 		if (fp->channels != num_channels)
988 			chconfig = 0;
989 
990 		if (protocol == UAC_VERSION_3)
991 			fp->chmap = chmap_v3;
992 		else
993 			fp->chmap = convert_chmap(fp->channels, chconfig,
994 						  protocol);
995 
996 		dev_dbg(&dev->dev, "%u:%d: add audio endpoint %#x\n", iface_no, altno, fp->endpoint);
997 		err = snd_usb_add_audio_stream(chip, stream, fp);
998 		if (err < 0) {
999 			list_del(&fp->list); /* unlink for avoiding double-free */
1000 			kfree(fp->rate_table);
1001 			kfree(fp->chmap);
1002 			kfree(fp);
1003 			return err;
1004 		}
1005 		/* try to set the interface... */
1006 		usb_set_interface(chip->dev, iface_no, altno);
1007 		snd_usb_init_pitch(chip, iface_no, alts, fp);
1008 		snd_usb_init_sample_rate(chip, iface_no, alts, fp, fp->rate_max);
1009 	}
1010 	return 0;
1011 }
1012 
1013