xref: /linux/sound/usb/stream.c (revision 6eb2fb3170549737207974c2c6ad34bcc2f3025e)
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 
24 #include <sound/core.h>
25 #include <sound/pcm.h>
26 #include <sound/control.h>
27 #include <sound/tlv.h>
28 
29 #include "usbaudio.h"
30 #include "card.h"
31 #include "proc.h"
32 #include "quirks.h"
33 #include "endpoint.h"
34 #include "pcm.h"
35 #include "helper.h"
36 #include "format.h"
37 #include "clock.h"
38 #include "stream.h"
39 
40 /*
41  * free a substream
42  */
43 static void free_substream(struct snd_usb_substream *subs)
44 {
45 	struct audioformat *fp, *n;
46 
47 	if (!subs->num_formats)
48 		return; /* not initialized */
49 	list_for_each_entry_safe(fp, n, &subs->fmt_list, list) {
50 		kfree(fp->rate_table);
51 		kfree(fp->chmap);
52 		kfree(fp);
53 	}
54 	kfree(subs->rate_list.list);
55 }
56 
57 
58 /*
59  * free a usb stream instance
60  */
61 static void snd_usb_audio_stream_free(struct snd_usb_stream *stream)
62 {
63 	free_substream(&stream->substream[0]);
64 	free_substream(&stream->substream[1]);
65 	list_del(&stream->list);
66 	kfree(stream);
67 }
68 
69 static void snd_usb_audio_pcm_free(struct snd_pcm *pcm)
70 {
71 	struct snd_usb_stream *stream = pcm->private_data;
72 	if (stream) {
73 		stream->pcm = NULL;
74 		snd_usb_audio_stream_free(stream);
75 	}
76 }
77 
78 /*
79  * initialize the substream instance.
80  */
81 
82 static void snd_usb_init_substream(struct snd_usb_stream *as,
83 				   int stream,
84 				   struct audioformat *fp)
85 {
86 	struct snd_usb_substream *subs = &as->substream[stream];
87 
88 	INIT_LIST_HEAD(&subs->fmt_list);
89 	spin_lock_init(&subs->lock);
90 
91 	subs->stream = as;
92 	subs->direction = stream;
93 	subs->dev = as->chip->dev;
94 	subs->txfr_quirk = as->chip->txfr_quirk;
95 	subs->speed = snd_usb_get_speed(subs->dev);
96 	subs->pkt_offset_adj = 0;
97 
98 	snd_usb_set_pcm_ops(as->pcm, stream);
99 
100 	list_add_tail(&fp->list, &subs->fmt_list);
101 	subs->formats |= fp->formats;
102 	subs->num_formats++;
103 	subs->fmt_type = fp->fmt_type;
104 	subs->ep_num = fp->endpoint;
105 	if (fp->channels > subs->channels_max)
106 		subs->channels_max = fp->channels;
107 }
108 
109 /* kctl callbacks for usb-audio channel maps */
110 static int usb_chmap_ctl_info(struct snd_kcontrol *kcontrol,
111 			      struct snd_ctl_elem_info *uinfo)
112 {
113 	struct snd_pcm_chmap *info = snd_kcontrol_chip(kcontrol);
114 	struct snd_usb_substream *subs = info->private_data;
115 
116 	uinfo->type = SNDRV_CTL_ELEM_TYPE_INTEGER;
117 	uinfo->count = subs->channels_max;
118 	uinfo->value.integer.min = 0;
119 	uinfo->value.integer.max = SNDRV_CHMAP_LAST;
120 	return 0;
121 }
122 
123 /* check whether a duplicated entry exists in the audiofmt list */
124 static bool have_dup_chmap(struct snd_usb_substream *subs,
125 			   struct audioformat *fp)
126 {
127 	struct list_head *p;
128 
129 	for (p = fp->list.prev; p != &subs->fmt_list; p = p->prev) {
130 		struct audioformat *prev;
131 		prev = list_entry(p, struct audioformat, 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_BLC,	/* bottom left center */
277 		SNDRV_CHMAP_BRC,	/* bottom right center */
278 		0 /* terminator */
279 	};
280 	struct snd_pcm_chmap_elem *chmap;
281 	const unsigned int *maps;
282 	int c;
283 
284 	if (!bits)
285 		return NULL;
286 	if (channels > ARRAY_SIZE(chmap->map))
287 		return NULL;
288 
289 	chmap = kzalloc(sizeof(*chmap), GFP_KERNEL);
290 	if (!chmap)
291 		return NULL;
292 
293 	maps = protocol == UAC_VERSION_2 ? uac2_maps : uac1_maps;
294 	chmap->channels = channels;
295 	c = 0;
296 	for (; bits && *maps; maps++, bits >>= 1) {
297 		if (bits & 1)
298 			chmap->map[c++] = *maps;
299 	}
300 
301 	for (; c < channels; c++)
302 		chmap->map[c] = SNDRV_CHMAP_UNKNOWN;
303 
304 	return chmap;
305 }
306 
307 /*
308  * add this endpoint to the chip instance.
309  * if a stream with the same endpoint already exists, append to it.
310  * if not, create a new pcm stream.
311  */
312 int snd_usb_add_audio_stream(struct snd_usb_audio *chip,
313 			     int stream,
314 			     struct audioformat *fp)
315 {
316 	struct snd_usb_stream *as;
317 	struct snd_usb_substream *subs;
318 	struct snd_pcm *pcm;
319 	int err;
320 
321 	list_for_each_entry(as, &chip->pcm_list, list) {
322 		if (as->fmt_type != fp->fmt_type)
323 			continue;
324 		subs = &as->substream[stream];
325 		if (subs->ep_num == fp->endpoint) {
326 			list_add_tail(&fp->list, &subs->fmt_list);
327 			subs->num_formats++;
328 			subs->formats |= fp->formats;
329 			return 0;
330 		}
331 	}
332 	/* look for an empty stream */
333 	list_for_each_entry(as, &chip->pcm_list, list) {
334 		if (as->fmt_type != fp->fmt_type)
335 			continue;
336 		subs = &as->substream[stream];
337 		if (subs->ep_num)
338 			continue;
339 		err = snd_pcm_new_stream(as->pcm, stream, 1);
340 		if (err < 0)
341 			return err;
342 		snd_usb_init_substream(as, stream, fp);
343 		return add_chmap(as->pcm, stream, subs);
344 	}
345 
346 	/* create a new pcm */
347 	as = kzalloc(sizeof(*as), GFP_KERNEL);
348 	if (!as)
349 		return -ENOMEM;
350 	as->pcm_index = chip->pcm_devs;
351 	as->chip = chip;
352 	as->fmt_type = fp->fmt_type;
353 	err = snd_pcm_new(chip->card, "USB Audio", chip->pcm_devs,
354 			  stream == SNDRV_PCM_STREAM_PLAYBACK ? 1 : 0,
355 			  stream == SNDRV_PCM_STREAM_PLAYBACK ? 0 : 1,
356 			  &pcm);
357 	if (err < 0) {
358 		kfree(as);
359 		return err;
360 	}
361 	as->pcm = pcm;
362 	pcm->private_data = as;
363 	pcm->private_free = snd_usb_audio_pcm_free;
364 	pcm->info_flags = 0;
365 	if (chip->pcm_devs > 0)
366 		sprintf(pcm->name, "USB Audio #%d", chip->pcm_devs);
367 	else
368 		strcpy(pcm->name, "USB Audio");
369 
370 	snd_usb_init_substream(as, stream, fp);
371 
372 	list_add(&as->list, &chip->pcm_list);
373 	chip->pcm_devs++;
374 
375 	snd_usb_proc_pcm_format_add(as);
376 
377 	return add_chmap(pcm, stream, &as->substream[stream]);
378 }
379 
380 static int parse_uac_endpoint_attributes(struct snd_usb_audio *chip,
381 					 struct usb_host_interface *alts,
382 					 int protocol, int iface_no)
383 {
384 	/* parsed with a v1 header here. that's ok as we only look at the
385 	 * header first which is the same for both versions */
386 	struct uac_iso_endpoint_descriptor *csep;
387 	struct usb_interface_descriptor *altsd = get_iface_desc(alts);
388 	int attributes = 0;
389 
390 	csep = snd_usb_find_desc(alts->endpoint[0].extra, alts->endpoint[0].extralen, NULL, USB_DT_CS_ENDPOINT);
391 
392 	/* Creamware Noah has this descriptor after the 2nd endpoint */
393 	if (!csep && altsd->bNumEndpoints >= 2)
394 		csep = snd_usb_find_desc(alts->endpoint[1].extra, alts->endpoint[1].extralen, NULL, USB_DT_CS_ENDPOINT);
395 
396 	/*
397 	 * If we can't locate the USB_DT_CS_ENDPOINT descriptor in the extra
398 	 * bytes after the first endpoint, go search the entire interface.
399 	 * Some devices have it directly *before* the standard endpoint.
400 	 */
401 	if (!csep)
402 		csep = snd_usb_find_desc(alts->extra, alts->extralen, NULL, USB_DT_CS_ENDPOINT);
403 
404 	if (!csep || csep->bLength < 7 ||
405 	    csep->bDescriptorSubtype != UAC_EP_GENERAL) {
406 		snd_printk(KERN_WARNING "%d:%u:%d : no or invalid"
407 			   " class specific endpoint descriptor\n",
408 			   chip->dev->devnum, iface_no,
409 			   altsd->bAlternateSetting);
410 		return 0;
411 	}
412 
413 	if (protocol == UAC_VERSION_1) {
414 		attributes = csep->bmAttributes;
415 	} else {
416 		struct uac2_iso_endpoint_descriptor *csep2 =
417 			(struct uac2_iso_endpoint_descriptor *) csep;
418 
419 		attributes = csep->bmAttributes & UAC_EP_CS_ATTR_FILL_MAX;
420 
421 		/* emulate the endpoint attributes of a v1 device */
422 		if (csep2->bmControls & UAC2_CONTROL_PITCH)
423 			attributes |= UAC_EP_CS_ATTR_PITCH_CONTROL;
424 	}
425 
426 	return attributes;
427 }
428 
429 /* find an input terminal descriptor (either UAC1 or UAC2) with the given
430  * terminal id
431  */
432 static void *
433 snd_usb_find_input_terminal_descriptor(struct usb_host_interface *ctrl_iface,
434 					       int terminal_id)
435 {
436 	struct uac2_input_terminal_descriptor *term = NULL;
437 
438 	while ((term = snd_usb_find_csint_desc(ctrl_iface->extra,
439 					       ctrl_iface->extralen,
440 					       term, UAC_INPUT_TERMINAL))) {
441 		if (term->bTerminalID == terminal_id)
442 			return term;
443 	}
444 
445 	return NULL;
446 }
447 
448 static struct uac2_output_terminal_descriptor *
449 	snd_usb_find_output_terminal_descriptor(struct usb_host_interface *ctrl_iface,
450 						int terminal_id)
451 {
452 	struct uac2_output_terminal_descriptor *term = NULL;
453 
454 	while ((term = snd_usb_find_csint_desc(ctrl_iface->extra,
455 					       ctrl_iface->extralen,
456 					       term, UAC_OUTPUT_TERMINAL))) {
457 		if (term->bTerminalID == terminal_id)
458 			return term;
459 	}
460 
461 	return NULL;
462 }
463 
464 int snd_usb_parse_audio_interface(struct snd_usb_audio *chip, int iface_no)
465 {
466 	struct usb_device *dev;
467 	struct usb_interface *iface;
468 	struct usb_host_interface *alts;
469 	struct usb_interface_descriptor *altsd;
470 	int i, altno, err, stream;
471 	unsigned int format = 0, num_channels = 0;
472 	struct audioformat *fp = NULL;
473 	int num, protocol, clock = 0;
474 	struct uac_format_type_i_continuous_descriptor *fmt;
475 	unsigned int chconfig;
476 
477 	dev = chip->dev;
478 
479 	/* parse the interface's altsettings */
480 	iface = usb_ifnum_to_if(dev, iface_no);
481 
482 	num = iface->num_altsetting;
483 
484 	/*
485 	 * Dallas DS4201 workaround: It presents 5 altsettings, but the last
486 	 * one misses syncpipe, and does not produce any sound.
487 	 */
488 	if (chip->usb_id == USB_ID(0x04fa, 0x4201))
489 		num = 4;
490 
491 	for (i = 0; i < num; i++) {
492 		alts = &iface->altsetting[i];
493 		altsd = get_iface_desc(alts);
494 		protocol = altsd->bInterfaceProtocol;
495 		/* skip invalid one */
496 		if ((altsd->bInterfaceClass != USB_CLASS_AUDIO &&
497 		     altsd->bInterfaceClass != USB_CLASS_VENDOR_SPEC) ||
498 		    (altsd->bInterfaceSubClass != USB_SUBCLASS_AUDIOSTREAMING &&
499 		     altsd->bInterfaceSubClass != USB_SUBCLASS_VENDOR_SPEC) ||
500 		    altsd->bNumEndpoints < 1 ||
501 		    le16_to_cpu(get_endpoint(alts, 0)->wMaxPacketSize) == 0)
502 			continue;
503 		/* must be isochronous */
504 		if ((get_endpoint(alts, 0)->bmAttributes & USB_ENDPOINT_XFERTYPE_MASK) !=
505 		    USB_ENDPOINT_XFER_ISOC)
506 			continue;
507 		/* check direction */
508 		stream = (get_endpoint(alts, 0)->bEndpointAddress & USB_DIR_IN) ?
509 			SNDRV_PCM_STREAM_CAPTURE : SNDRV_PCM_STREAM_PLAYBACK;
510 		altno = altsd->bAlternateSetting;
511 
512 		if (snd_usb_apply_interface_quirk(chip, iface_no, altno))
513 			continue;
514 
515 		chconfig = 0;
516 		/* get audio formats */
517 		switch (protocol) {
518 		default:
519 			snd_printdd(KERN_WARNING "%d:%u:%d: unknown interface protocol %#02x, assuming v1\n",
520 				    dev->devnum, iface_no, altno, protocol);
521 			protocol = UAC_VERSION_1;
522 			/* fall through */
523 
524 		case UAC_VERSION_1: {
525 			struct uac1_as_header_descriptor *as =
526 				snd_usb_find_csint_desc(alts->extra, alts->extralen, NULL, UAC_AS_GENERAL);
527 			struct uac_input_terminal_descriptor *iterm;
528 
529 			if (!as) {
530 				snd_printk(KERN_ERR "%d:%u:%d : UAC_AS_GENERAL descriptor not found\n",
531 					   dev->devnum, iface_no, altno);
532 				continue;
533 			}
534 
535 			if (as->bLength < sizeof(*as)) {
536 				snd_printk(KERN_ERR "%d:%u:%d : invalid UAC_AS_GENERAL desc\n",
537 					   dev->devnum, iface_no, altno);
538 				continue;
539 			}
540 
541 			format = le16_to_cpu(as->wFormatTag); /* remember the format value */
542 
543 			iterm = snd_usb_find_input_terminal_descriptor(chip->ctrl_intf,
544 								       as->bTerminalLink);
545 			if (iterm) {
546 				num_channels = iterm->bNrChannels;
547 				chconfig = le16_to_cpu(iterm->wChannelConfig);
548 			}
549 
550 			break;
551 		}
552 
553 		case UAC_VERSION_2: {
554 			struct uac2_input_terminal_descriptor *input_term;
555 			struct uac2_output_terminal_descriptor *output_term;
556 			struct uac2_as_header_descriptor *as =
557 				snd_usb_find_csint_desc(alts->extra, alts->extralen, NULL, UAC_AS_GENERAL);
558 
559 			if (!as) {
560 				snd_printk(KERN_ERR "%d:%u:%d : UAC_AS_GENERAL descriptor not found\n",
561 					   dev->devnum, iface_no, altno);
562 				continue;
563 			}
564 
565 			if (as->bLength < sizeof(*as)) {
566 				snd_printk(KERN_ERR "%d:%u:%d : invalid UAC_AS_GENERAL desc\n",
567 					   dev->devnum, iface_no, altno);
568 				continue;
569 			}
570 
571 			num_channels = as->bNrChannels;
572 			format = le32_to_cpu(as->bmFormats);
573 
574 			/* lookup the terminal associated to this interface
575 			 * to extract the clock */
576 			input_term = snd_usb_find_input_terminal_descriptor(chip->ctrl_intf,
577 									    as->bTerminalLink);
578 			if (input_term) {
579 				clock = input_term->bCSourceID;
580 				chconfig = le32_to_cpu(input_term->bmChannelConfig);
581 				break;
582 			}
583 
584 			output_term = snd_usb_find_output_terminal_descriptor(chip->ctrl_intf,
585 									      as->bTerminalLink);
586 			if (output_term) {
587 				clock = output_term->bCSourceID;
588 				break;
589 			}
590 
591 			snd_printk(KERN_ERR "%d:%u:%d : bogus bTerminalLink %d\n",
592 				   dev->devnum, iface_no, altno, as->bTerminalLink);
593 			continue;
594 		}
595 		}
596 
597 		/* get format type */
598 		fmt = snd_usb_find_csint_desc(alts->extra, alts->extralen, NULL, UAC_FORMAT_TYPE);
599 		if (!fmt) {
600 			snd_printk(KERN_ERR "%d:%u:%d : no UAC_FORMAT_TYPE desc\n",
601 				   dev->devnum, iface_no, altno);
602 			continue;
603 		}
604 		if (((protocol == UAC_VERSION_1) && (fmt->bLength < 8)) ||
605 		    ((protocol == UAC_VERSION_2) && (fmt->bLength < 6))) {
606 			snd_printk(KERN_ERR "%d:%u:%d : invalid UAC_FORMAT_TYPE desc\n",
607 				   dev->devnum, iface_no, altno);
608 			continue;
609 		}
610 
611 		/*
612 		 * Blue Microphones workaround: The last altsetting is identical
613 		 * with the previous one, except for a larger packet size, but
614 		 * is actually a mislabeled two-channel setting; ignore it.
615 		 */
616 		if (fmt->bNrChannels == 1 &&
617 		    fmt->bSubframeSize == 2 &&
618 		    altno == 2 && num == 3 &&
619 		    fp && fp->altsetting == 1 && fp->channels == 1 &&
620 		    fp->formats == SNDRV_PCM_FMTBIT_S16_LE &&
621 		    protocol == UAC_VERSION_1 &&
622 		    le16_to_cpu(get_endpoint(alts, 0)->wMaxPacketSize) ==
623 							fp->maxpacksize * 2)
624 			continue;
625 
626 		fp = kzalloc(sizeof(*fp), GFP_KERNEL);
627 		if (! fp) {
628 			snd_printk(KERN_ERR "cannot malloc\n");
629 			return -ENOMEM;
630 		}
631 
632 		fp->iface = iface_no;
633 		fp->altsetting = altno;
634 		fp->altset_idx = i;
635 		fp->endpoint = get_endpoint(alts, 0)->bEndpointAddress;
636 		fp->ep_attr = get_endpoint(alts, 0)->bmAttributes;
637 		fp->datainterval = snd_usb_parse_datainterval(chip, alts);
638 		fp->maxpacksize = le16_to_cpu(get_endpoint(alts, 0)->wMaxPacketSize);
639 		fp->channels = num_channels;
640 		if (snd_usb_get_speed(dev) == USB_SPEED_HIGH)
641 			fp->maxpacksize = (((fp->maxpacksize >> 11) & 3) + 1)
642 					* (fp->maxpacksize & 0x7ff);
643 		fp->attributes = parse_uac_endpoint_attributes(chip, alts, protocol, iface_no);
644 		fp->clock = clock;
645 		fp->chmap = convert_chmap(num_channels, chconfig, protocol);
646 
647 		/* some quirks for attributes here */
648 
649 		switch (chip->usb_id) {
650 		case USB_ID(0x0a92, 0x0053): /* AudioTrak Optoplay */
651 			/* Optoplay sets the sample rate attribute although
652 			 * it seems not supporting it in fact.
653 			 */
654 			fp->attributes &= ~UAC_EP_CS_ATTR_SAMPLE_RATE;
655 			break;
656 		case USB_ID(0x041e, 0x3020): /* Creative SB Audigy 2 NX */
657 		case USB_ID(0x0763, 0x2003): /* M-Audio Audiophile USB */
658 			/* doesn't set the sample rate attribute, but supports it */
659 			fp->attributes |= UAC_EP_CS_ATTR_SAMPLE_RATE;
660 			break;
661 		case USB_ID(0x0763, 0x2001):  /* M-Audio Quattro USB */
662 		case USB_ID(0x0763, 0x2012):  /* M-Audio Fast Track Pro USB */
663 		case USB_ID(0x047f, 0x0ca1): /* plantronics headset */
664 		case USB_ID(0x077d, 0x07af): /* Griffin iMic (note that there is
665 						an older model 77d:223) */
666 		/*
667 		 * plantronics headset and Griffin iMic have set adaptive-in
668 		 * although it's really not...
669 		 */
670 			fp->ep_attr &= ~USB_ENDPOINT_SYNCTYPE;
671 			if (stream == SNDRV_PCM_STREAM_PLAYBACK)
672 				fp->ep_attr |= USB_ENDPOINT_SYNC_ADAPTIVE;
673 			else
674 				fp->ep_attr |= USB_ENDPOINT_SYNC_SYNC;
675 			break;
676 		}
677 
678 		/* ok, let's parse further... */
679 		if (snd_usb_parse_audio_format(chip, fp, format, fmt, stream, alts) < 0) {
680 			kfree(fp->rate_table);
681 			kfree(fp->chmap);
682 			kfree(fp);
683 			fp = NULL;
684 			continue;
685 		}
686 
687 		snd_printdd(KERN_INFO "%d:%u:%d: add audio endpoint %#x\n", dev->devnum, iface_no, altno, fp->endpoint);
688 		err = snd_usb_add_audio_stream(chip, stream, fp);
689 		if (err < 0) {
690 			kfree(fp->rate_table);
691 			kfree(fp->chmap);
692 			kfree(fp);
693 			return err;
694 		}
695 		/* try to set the interface... */
696 		usb_set_interface(chip->dev, iface_no, altno);
697 		snd_usb_init_pitch(chip, iface_no, alts, fp);
698 		snd_usb_init_sample_rate(chip, iface_no, alts, fp, fp->rate_max);
699 	}
700 	return 0;
701 }
702 
703