xref: /openbmc/linux/sound/usb/card.c (revision ae213c44)
1 /*
2  *   (Tentative) USB Audio Driver for ALSA
3  *
4  *   Copyright (c) 2002 by Takashi Iwai <tiwai@suse.de>
5  *
6  *   Many codes borrowed from audio.c by
7  *	    Alan Cox (alan@lxorguk.ukuu.org.uk)
8  *	    Thomas Sailer (sailer@ife.ee.ethz.ch)
9  *
10  *   Audio Class 3.0 support by Ruslan Bilovol <ruslan.bilovol@gmail.com>
11  *
12  *   This program is free software; you can redistribute it and/or modify
13  *   it under the terms of the GNU General Public License as published by
14  *   the Free Software Foundation; either version 2 of the License, or
15  *   (at your option) any later version.
16  *
17  *   This program is distributed in the hope that it will be useful,
18  *   but WITHOUT ANY WARRANTY; without even the implied warranty of
19  *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
20  *   GNU General Public License for more details.
21  *
22  *   You should have received a copy of the GNU General Public License
23  *   along with this program; if not, write to the Free Software
24  *   Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307 USA
25  *
26  *
27  *  NOTES:
28  *
29  *   - the linked URBs would be preferred but not used so far because of
30  *     the instability of unlinking.
31  *   - type II is not supported properly.  there is no device which supports
32  *     this type *correctly*.  SB extigy looks as if it supports, but it's
33  *     indeed an AC3 stream packed in SPDIF frames (i.e. no real AC3 stream).
34  */
35 
36 
37 #include <linux/bitops.h>
38 #include <linux/init.h>
39 #include <linux/list.h>
40 #include <linux/slab.h>
41 #include <linux/string.h>
42 #include <linux/ctype.h>
43 #include <linux/usb.h>
44 #include <linux/moduleparam.h>
45 #include <linux/mutex.h>
46 #include <linux/usb/audio.h>
47 #include <linux/usb/audio-v2.h>
48 #include <linux/usb/audio-v3.h>
49 #include <linux/module.h>
50 
51 #include <sound/control.h>
52 #include <sound/core.h>
53 #include <sound/info.h>
54 #include <sound/pcm.h>
55 #include <sound/pcm_params.h>
56 #include <sound/initval.h>
57 
58 #include "usbaudio.h"
59 #include "card.h"
60 #include "midi.h"
61 #include "mixer.h"
62 #include "proc.h"
63 #include "quirks.h"
64 #include "endpoint.h"
65 #include "helper.h"
66 #include "debug.h"
67 #include "pcm.h"
68 #include "format.h"
69 #include "power.h"
70 #include "stream.h"
71 #include "media.h"
72 
73 MODULE_AUTHOR("Takashi Iwai <tiwai@suse.de>");
74 MODULE_DESCRIPTION("USB Audio");
75 MODULE_LICENSE("GPL");
76 MODULE_SUPPORTED_DEVICE("{{Generic,USB Audio}}");
77 
78 
79 static int index[SNDRV_CARDS] = SNDRV_DEFAULT_IDX;	/* Index 0-MAX */
80 static char *id[SNDRV_CARDS] = SNDRV_DEFAULT_STR;	/* ID for this card */
81 static bool enable[SNDRV_CARDS] = SNDRV_DEFAULT_ENABLE_PNP;/* Enable this card */
82 /* Vendor/product IDs for this card */
83 static int vid[SNDRV_CARDS] = { [0 ... (SNDRV_CARDS-1)] = -1 };
84 static int pid[SNDRV_CARDS] = { [0 ... (SNDRV_CARDS-1)] = -1 };
85 static int device_setup[SNDRV_CARDS]; /* device parameter for this card */
86 static bool ignore_ctl_error;
87 static bool autoclock = true;
88 static char *quirk_alias[SNDRV_CARDS];
89 
90 bool snd_usb_use_vmalloc = true;
91 
92 module_param_array(index, int, NULL, 0444);
93 MODULE_PARM_DESC(index, "Index value for the USB audio adapter.");
94 module_param_array(id, charp, NULL, 0444);
95 MODULE_PARM_DESC(id, "ID string for the USB audio adapter.");
96 module_param_array(enable, bool, NULL, 0444);
97 MODULE_PARM_DESC(enable, "Enable USB audio adapter.");
98 module_param_array(vid, int, NULL, 0444);
99 MODULE_PARM_DESC(vid, "Vendor ID for the USB audio device.");
100 module_param_array(pid, int, NULL, 0444);
101 MODULE_PARM_DESC(pid, "Product ID for the USB audio device.");
102 module_param_array(device_setup, int, NULL, 0444);
103 MODULE_PARM_DESC(device_setup, "Specific device setup (if needed).");
104 module_param(ignore_ctl_error, bool, 0444);
105 MODULE_PARM_DESC(ignore_ctl_error,
106 		 "Ignore errors from USB controller for mixer interfaces.");
107 module_param(autoclock, bool, 0444);
108 MODULE_PARM_DESC(autoclock, "Enable auto-clock selection for UAC2 devices (default: yes).");
109 module_param_array(quirk_alias, charp, NULL, 0444);
110 MODULE_PARM_DESC(quirk_alias, "Quirk aliases, e.g. 0123abcd:5678beef.");
111 module_param_named(use_vmalloc, snd_usb_use_vmalloc, bool, 0444);
112 MODULE_PARM_DESC(use_vmalloc, "Use vmalloc for PCM intermediate buffers (default: yes).");
113 
114 /*
115  * we keep the snd_usb_audio_t instances by ourselves for merging
116  * the all interfaces on the same card as one sound device.
117  */
118 
119 static DEFINE_MUTEX(register_mutex);
120 static struct snd_usb_audio *usb_chip[SNDRV_CARDS];
121 static struct usb_driver usb_audio_driver;
122 
123 /*
124  * disconnect streams
125  * called from usb_audio_disconnect()
126  */
127 static void snd_usb_stream_disconnect(struct snd_usb_stream *as)
128 {
129 	int idx;
130 	struct snd_usb_substream *subs;
131 
132 	for (idx = 0; idx < 2; idx++) {
133 		subs = &as->substream[idx];
134 		if (!subs->num_formats)
135 			continue;
136 		subs->interface = -1;
137 		subs->data_endpoint = NULL;
138 		subs->sync_endpoint = NULL;
139 	}
140 }
141 
142 static int snd_usb_create_stream(struct snd_usb_audio *chip, int ctrlif, int interface)
143 {
144 	struct usb_device *dev = chip->dev;
145 	struct usb_host_interface *alts;
146 	struct usb_interface_descriptor *altsd;
147 	struct usb_interface *iface = usb_ifnum_to_if(dev, interface);
148 
149 	if (!iface) {
150 		dev_err(&dev->dev, "%u:%d : does not exist\n",
151 			ctrlif, interface);
152 		return -EINVAL;
153 	}
154 
155 	alts = &iface->altsetting[0];
156 	altsd = get_iface_desc(alts);
157 
158 	/*
159 	 * Android with both accessory and audio interfaces enabled gets the
160 	 * interface numbers wrong.
161 	 */
162 	if ((chip->usb_id == USB_ID(0x18d1, 0x2d04) ||
163 	     chip->usb_id == USB_ID(0x18d1, 0x2d05)) &&
164 	    interface == 0 &&
165 	    altsd->bInterfaceClass == USB_CLASS_VENDOR_SPEC &&
166 	    altsd->bInterfaceSubClass == USB_SUBCLASS_VENDOR_SPEC) {
167 		interface = 2;
168 		iface = usb_ifnum_to_if(dev, interface);
169 		if (!iface)
170 			return -EINVAL;
171 		alts = &iface->altsetting[0];
172 		altsd = get_iface_desc(alts);
173 	}
174 
175 	if (usb_interface_claimed(iface)) {
176 		dev_dbg(&dev->dev, "%d:%d: skipping, already claimed\n",
177 			ctrlif, interface);
178 		return -EINVAL;
179 	}
180 
181 	if ((altsd->bInterfaceClass == USB_CLASS_AUDIO ||
182 	     altsd->bInterfaceClass == USB_CLASS_VENDOR_SPEC) &&
183 	    altsd->bInterfaceSubClass == USB_SUBCLASS_MIDISTREAMING) {
184 		int err = __snd_usbmidi_create(chip->card, iface,
185 					     &chip->midi_list, NULL,
186 					     chip->usb_id);
187 		if (err < 0) {
188 			dev_err(&dev->dev,
189 				"%u:%d: cannot create sequencer device\n",
190 				ctrlif, interface);
191 			return -EINVAL;
192 		}
193 		usb_driver_claim_interface(&usb_audio_driver, iface, (void *)-1L);
194 
195 		return 0;
196 	}
197 
198 	if ((altsd->bInterfaceClass != USB_CLASS_AUDIO &&
199 	     altsd->bInterfaceClass != USB_CLASS_VENDOR_SPEC) ||
200 	    altsd->bInterfaceSubClass != USB_SUBCLASS_AUDIOSTREAMING) {
201 		dev_dbg(&dev->dev,
202 			"%u:%d: skipping non-supported interface %d\n",
203 			ctrlif, interface, altsd->bInterfaceClass);
204 		/* skip non-supported classes */
205 		return -EINVAL;
206 	}
207 
208 	if (snd_usb_get_speed(dev) == USB_SPEED_LOW) {
209 		dev_err(&dev->dev, "low speed audio streaming not supported\n");
210 		return -EINVAL;
211 	}
212 
213 	if (! snd_usb_parse_audio_interface(chip, interface)) {
214 		usb_set_interface(dev, interface, 0); /* reset the current interface */
215 		usb_driver_claim_interface(&usb_audio_driver, iface, (void *)-1L);
216 	}
217 
218 	return 0;
219 }
220 
221 /*
222  * parse audio control descriptor and create pcm/midi streams
223  */
224 static int snd_usb_create_streams(struct snd_usb_audio *chip, int ctrlif)
225 {
226 	struct usb_device *dev = chip->dev;
227 	struct usb_host_interface *host_iface;
228 	struct usb_interface_descriptor *altsd;
229 	int i, protocol;
230 
231 	/* find audiocontrol interface */
232 	host_iface = &usb_ifnum_to_if(dev, ctrlif)->altsetting[0];
233 	altsd = get_iface_desc(host_iface);
234 	protocol = altsd->bInterfaceProtocol;
235 
236 	switch (protocol) {
237 	default:
238 		dev_warn(&dev->dev,
239 			 "unknown interface protocol %#02x, assuming v1\n",
240 			 protocol);
241 		/* fall through */
242 
243 	case UAC_VERSION_1: {
244 		struct uac1_ac_header_descriptor *h1;
245 		int rest_bytes;
246 
247 		h1 = snd_usb_find_csint_desc(host_iface->extra,
248 							 host_iface->extralen,
249 							 NULL, UAC_HEADER);
250 		if (!h1 || h1->bLength < sizeof(*h1)) {
251 			dev_err(&dev->dev, "cannot find UAC_HEADER\n");
252 			return -EINVAL;
253 		}
254 
255 		rest_bytes = (void *)(host_iface->extra +
256 				host_iface->extralen) - (void *)h1;
257 
258 		/* just to be sure -- this shouldn't hit at all */
259 		if (rest_bytes <= 0) {
260 			dev_err(&dev->dev, "invalid control header\n");
261 			return -EINVAL;
262 		}
263 
264 		if (rest_bytes < sizeof(*h1)) {
265 			dev_err(&dev->dev, "too short v1 buffer descriptor\n");
266 			return -EINVAL;
267 		}
268 
269 		if (!h1->bInCollection) {
270 			dev_info(&dev->dev, "skipping empty audio interface (v1)\n");
271 			return -EINVAL;
272 		}
273 
274 		if (rest_bytes < h1->bLength) {
275 			dev_err(&dev->dev, "invalid buffer length (v1)\n");
276 			return -EINVAL;
277 		}
278 
279 		if (h1->bLength < sizeof(*h1) + h1->bInCollection) {
280 			dev_err(&dev->dev, "invalid UAC_HEADER (v1)\n");
281 			return -EINVAL;
282 		}
283 
284 		for (i = 0; i < h1->bInCollection; i++)
285 			snd_usb_create_stream(chip, ctrlif, h1->baInterfaceNr[i]);
286 
287 		break;
288 	}
289 
290 	case UAC_VERSION_2:
291 	case UAC_VERSION_3: {
292 		struct usb_interface_assoc_descriptor *assoc =
293 			usb_ifnum_to_if(dev, ctrlif)->intf_assoc;
294 
295 		if (!assoc) {
296 			/*
297 			 * Firmware writers cannot count to three.  So to find
298 			 * the IAD on the NuForce UDH-100, also check the next
299 			 * interface.
300 			 */
301 			struct usb_interface *iface =
302 				usb_ifnum_to_if(dev, ctrlif + 1);
303 			if (iface &&
304 			    iface->intf_assoc &&
305 			    iface->intf_assoc->bFunctionClass == USB_CLASS_AUDIO &&
306 			    iface->intf_assoc->bFunctionProtocol == UAC_VERSION_2)
307 				assoc = iface->intf_assoc;
308 		}
309 
310 		if (!assoc) {
311 			dev_err(&dev->dev, "Audio class v2/v3 interfaces need an interface association\n");
312 			return -EINVAL;
313 		}
314 
315 		if (protocol == UAC_VERSION_3) {
316 			int badd = assoc->bFunctionSubClass;
317 
318 			if (badd != UAC3_FUNCTION_SUBCLASS_FULL_ADC_3_0 &&
319 			    (badd < UAC3_FUNCTION_SUBCLASS_GENERIC_IO ||
320 			     badd > UAC3_FUNCTION_SUBCLASS_SPEAKERPHONE)) {
321 				dev_err(&dev->dev,
322 					"Unsupported UAC3 BADD profile\n");
323 				return -EINVAL;
324 			}
325 
326 			chip->badd_profile = badd;
327 		}
328 
329 		for (i = 0; i < assoc->bInterfaceCount; i++) {
330 			int intf = assoc->bFirstInterface + i;
331 
332 			if (intf != ctrlif)
333 				snd_usb_create_stream(chip, ctrlif, intf);
334 		}
335 
336 		break;
337 	}
338 	}
339 
340 	return 0;
341 }
342 
343 /*
344  * free the chip instance
345  *
346  * here we have to do not much, since pcm and controls are already freed
347  *
348  */
349 
350 static void snd_usb_audio_free(struct snd_card *card)
351 {
352 	struct snd_usb_audio *chip = card->private_data;
353 	struct snd_usb_endpoint *ep, *n;
354 
355 	list_for_each_entry_safe(ep, n, &chip->ep_list, list)
356 		snd_usb_endpoint_free(ep);
357 
358 	mutex_destroy(&chip->mutex);
359 	if (!atomic_read(&chip->shutdown))
360 		dev_set_drvdata(&chip->dev->dev, NULL);
361 }
362 
363 static void usb_audio_make_shortname(struct usb_device *dev,
364 				     struct snd_usb_audio *chip,
365 				     const struct snd_usb_audio_quirk *quirk)
366 {
367 	struct snd_card *card = chip->card;
368 
369 	if (quirk && quirk->product_name && *quirk->product_name) {
370 		strlcpy(card->shortname, quirk->product_name,
371 			sizeof(card->shortname));
372 		return;
373 	}
374 
375 	/* retrieve the device string as shortname */
376 	if (!dev->descriptor.iProduct ||
377 	    usb_string(dev, dev->descriptor.iProduct,
378 		       card->shortname, sizeof(card->shortname)) <= 0) {
379 		/* no name available from anywhere, so use ID */
380 		sprintf(card->shortname, "USB Device %#04x:%#04x",
381 			USB_ID_VENDOR(chip->usb_id),
382 			USB_ID_PRODUCT(chip->usb_id));
383 	}
384 
385 	strim(card->shortname);
386 }
387 
388 static void usb_audio_make_longname(struct usb_device *dev,
389 				    struct snd_usb_audio *chip,
390 				    const struct snd_usb_audio_quirk *quirk)
391 {
392 	struct snd_card *card = chip->card;
393 	int len;
394 
395 	/* shortcut - if any pre-defined string is given, use it */
396 	if (quirk && quirk->profile_name && *quirk->profile_name) {
397 		strlcpy(card->longname, quirk->profile_name,
398 			sizeof(card->longname));
399 		return;
400 	}
401 
402 	if (quirk && quirk->vendor_name && *quirk->vendor_name) {
403 		len = strlcpy(card->longname, quirk->vendor_name, sizeof(card->longname));
404 	} else {
405 		/* retrieve the vendor and device strings as longname */
406 		if (dev->descriptor.iManufacturer)
407 			len = usb_string(dev, dev->descriptor.iManufacturer,
408 					 card->longname, sizeof(card->longname));
409 		else
410 			len = 0;
411 		/* we don't really care if there isn't any vendor string */
412 	}
413 	if (len > 0) {
414 		strim(card->longname);
415 		if (*card->longname)
416 			strlcat(card->longname, " ", sizeof(card->longname));
417 	}
418 
419 	strlcat(card->longname, card->shortname, sizeof(card->longname));
420 
421 	len = strlcat(card->longname, " at ", sizeof(card->longname));
422 
423 	if (len < sizeof(card->longname))
424 		usb_make_path(dev, card->longname + len, sizeof(card->longname) - len);
425 
426 	switch (snd_usb_get_speed(dev)) {
427 	case USB_SPEED_LOW:
428 		strlcat(card->longname, ", low speed", sizeof(card->longname));
429 		break;
430 	case USB_SPEED_FULL:
431 		strlcat(card->longname, ", full speed", sizeof(card->longname));
432 		break;
433 	case USB_SPEED_HIGH:
434 		strlcat(card->longname, ", high speed", sizeof(card->longname));
435 		break;
436 	case USB_SPEED_SUPER:
437 		strlcat(card->longname, ", super speed", sizeof(card->longname));
438 		break;
439 	case USB_SPEED_SUPER_PLUS:
440 		strlcat(card->longname, ", super speed plus", sizeof(card->longname));
441 		break;
442 	default:
443 		break;
444 	}
445 }
446 
447 /*
448  * create a chip instance and set its names.
449  */
450 static int snd_usb_audio_create(struct usb_interface *intf,
451 				struct usb_device *dev, int idx,
452 				const struct snd_usb_audio_quirk *quirk,
453 				unsigned int usb_id,
454 				struct snd_usb_audio **rchip)
455 {
456 	struct snd_card *card;
457 	struct snd_usb_audio *chip;
458 	int err;
459 	char component[14];
460 
461 	*rchip = NULL;
462 
463 	switch (snd_usb_get_speed(dev)) {
464 	case USB_SPEED_LOW:
465 	case USB_SPEED_FULL:
466 	case USB_SPEED_HIGH:
467 	case USB_SPEED_WIRELESS:
468 	case USB_SPEED_SUPER:
469 	case USB_SPEED_SUPER_PLUS:
470 		break;
471 	default:
472 		dev_err(&dev->dev, "unknown device speed %d\n", snd_usb_get_speed(dev));
473 		return -ENXIO;
474 	}
475 
476 	err = snd_card_new(&intf->dev, index[idx], id[idx], THIS_MODULE,
477 			   sizeof(*chip), &card);
478 	if (err < 0) {
479 		dev_err(&dev->dev, "cannot create card instance %d\n", idx);
480 		return err;
481 	}
482 
483 	chip = card->private_data;
484 	mutex_init(&chip->mutex);
485 	init_waitqueue_head(&chip->shutdown_wait);
486 	chip->index = idx;
487 	chip->dev = dev;
488 	chip->card = card;
489 	chip->setup = device_setup[idx];
490 	chip->autoclock = autoclock;
491 	atomic_set(&chip->active, 1); /* avoid autopm during probing */
492 	atomic_set(&chip->usage_count, 0);
493 	atomic_set(&chip->shutdown, 0);
494 
495 	chip->usb_id = usb_id;
496 	INIT_LIST_HEAD(&chip->pcm_list);
497 	INIT_LIST_HEAD(&chip->ep_list);
498 	INIT_LIST_HEAD(&chip->midi_list);
499 	INIT_LIST_HEAD(&chip->mixer_list);
500 
501 	card->private_free = snd_usb_audio_free;
502 
503 	strcpy(card->driver, "USB-Audio");
504 	sprintf(component, "USB%04x:%04x",
505 		USB_ID_VENDOR(chip->usb_id), USB_ID_PRODUCT(chip->usb_id));
506 	snd_component_add(card, component);
507 
508 	usb_audio_make_shortname(dev, chip, quirk);
509 	usb_audio_make_longname(dev, chip, quirk);
510 
511 	snd_usb_audio_create_proc(chip);
512 
513 	*rchip = chip;
514 	return 0;
515 }
516 
517 /* look for a matching quirk alias id */
518 static bool get_alias_id(struct usb_device *dev, unsigned int *id)
519 {
520 	int i;
521 	unsigned int src, dst;
522 
523 	for (i = 0; i < ARRAY_SIZE(quirk_alias); i++) {
524 		if (!quirk_alias[i] ||
525 		    sscanf(quirk_alias[i], "%x:%x", &src, &dst) != 2 ||
526 		    src != *id)
527 			continue;
528 		dev_info(&dev->dev,
529 			 "device (%04x:%04x): applying quirk alias %04x:%04x\n",
530 			 USB_ID_VENDOR(*id), USB_ID_PRODUCT(*id),
531 			 USB_ID_VENDOR(dst), USB_ID_PRODUCT(dst));
532 		*id = dst;
533 		return true;
534 	}
535 
536 	return false;
537 }
538 
539 static const struct usb_device_id usb_audio_ids[]; /* defined below */
540 
541 /* look for the corresponding quirk */
542 static const struct snd_usb_audio_quirk *
543 get_alias_quirk(struct usb_device *dev, unsigned int id)
544 {
545 	const struct usb_device_id *p;
546 
547 	for (p = usb_audio_ids; p->match_flags; p++) {
548 		/* FIXME: this checks only vendor:product pair in the list */
549 		if ((p->match_flags & USB_DEVICE_ID_MATCH_DEVICE) ==
550 		    USB_DEVICE_ID_MATCH_DEVICE &&
551 		    p->idVendor == USB_ID_VENDOR(id) &&
552 		    p->idProduct == USB_ID_PRODUCT(id))
553 			return (const struct snd_usb_audio_quirk *)p->driver_info;
554 	}
555 
556 	return NULL;
557 }
558 
559 /*
560  * probe the active usb device
561  *
562  * note that this can be called multiple times per a device, when it
563  * includes multiple audio control interfaces.
564  *
565  * thus we check the usb device pointer and creates the card instance
566  * only at the first time.  the successive calls of this function will
567  * append the pcm interface to the corresponding card.
568  */
569 static int usb_audio_probe(struct usb_interface *intf,
570 			   const struct usb_device_id *usb_id)
571 {
572 	struct usb_device *dev = interface_to_usbdev(intf);
573 	const struct snd_usb_audio_quirk *quirk =
574 		(const struct snd_usb_audio_quirk *)usb_id->driver_info;
575 	struct snd_usb_audio *chip;
576 	int i, err;
577 	struct usb_host_interface *alts;
578 	int ifnum;
579 	u32 id;
580 
581 	alts = &intf->altsetting[0];
582 	ifnum = get_iface_desc(alts)->bInterfaceNumber;
583 	id = USB_ID(le16_to_cpu(dev->descriptor.idVendor),
584 		    le16_to_cpu(dev->descriptor.idProduct));
585 	if (get_alias_id(dev, &id))
586 		quirk = get_alias_quirk(dev, id);
587 	if (quirk && quirk->ifnum >= 0 && ifnum != quirk->ifnum)
588 		return -ENXIO;
589 
590 	err = snd_usb_apply_boot_quirk(dev, intf, quirk, id);
591 	if (err < 0)
592 		return err;
593 
594 	/*
595 	 * found a config.  now register to ALSA
596 	 */
597 
598 	/* check whether it's already registered */
599 	chip = NULL;
600 	mutex_lock(&register_mutex);
601 	for (i = 0; i < SNDRV_CARDS; i++) {
602 		if (usb_chip[i] && usb_chip[i]->dev == dev) {
603 			if (atomic_read(&usb_chip[i]->shutdown)) {
604 				dev_err(&dev->dev, "USB device is in the shutdown state, cannot create a card instance\n");
605 				err = -EIO;
606 				goto __error;
607 			}
608 			chip = usb_chip[i];
609 			atomic_inc(&chip->active); /* avoid autopm */
610 			break;
611 		}
612 	}
613 	if (! chip) {
614 		/* it's a fresh one.
615 		 * now look for an empty slot and create a new card instance
616 		 */
617 		for (i = 0; i < SNDRV_CARDS; i++)
618 			if (!usb_chip[i] &&
619 			    (vid[i] == -1 || vid[i] == USB_ID_VENDOR(id)) &&
620 			    (pid[i] == -1 || pid[i] == USB_ID_PRODUCT(id))) {
621 				if (enable[i]) {
622 					err = snd_usb_audio_create(intf, dev, i, quirk,
623 								   id, &chip);
624 					if (err < 0)
625 						goto __error;
626 					chip->pm_intf = intf;
627 					break;
628 				} else if (vid[i] != -1 || pid[i] != -1) {
629 					dev_info(&dev->dev,
630 						 "device (%04x:%04x) is disabled\n",
631 						 USB_ID_VENDOR(id),
632 						 USB_ID_PRODUCT(id));
633 					err = -ENOENT;
634 					goto __error;
635 				}
636 			}
637 		if (!chip) {
638 			dev_err(&dev->dev, "no available usb audio device\n");
639 			err = -ENODEV;
640 			goto __error;
641 		}
642 	}
643 	dev_set_drvdata(&dev->dev, chip);
644 
645 	/*
646 	 * For devices with more than one control interface, we assume the
647 	 * first contains the audio controls. We might need a more specific
648 	 * check here in the future.
649 	 */
650 	if (!chip->ctrl_intf)
651 		chip->ctrl_intf = alts;
652 
653 	chip->txfr_quirk = 0;
654 	err = 1; /* continue */
655 	if (quirk && quirk->ifnum != QUIRK_NO_INTERFACE) {
656 		/* need some special handlings */
657 		err = snd_usb_create_quirk(chip, intf, &usb_audio_driver, quirk);
658 		if (err < 0)
659 			goto __error;
660 	}
661 
662 	if (err > 0) {
663 		/* create normal USB audio interfaces */
664 		err = snd_usb_create_streams(chip, ifnum);
665 		if (err < 0)
666 			goto __error;
667 		err = snd_usb_create_mixer(chip, ifnum, ignore_ctl_error);
668 		if (err < 0)
669 			goto __error;
670 	}
671 
672 	/* we are allowed to call snd_card_register() many times */
673 	err = snd_card_register(chip->card);
674 	if (err < 0)
675 		goto __error;
676 
677 	if (quirk && quirk->shares_media_device) {
678 		/* don't want to fail when snd_media_device_create() fails */
679 		snd_media_device_create(chip, intf);
680 	}
681 
682 	usb_chip[chip->index] = chip;
683 	chip->num_interfaces++;
684 	usb_set_intfdata(intf, chip);
685 	atomic_dec(&chip->active);
686 	mutex_unlock(&register_mutex);
687 	return 0;
688 
689  __error:
690 	if (chip) {
691 		/* chip->active is inside the chip->card object,
692 		 * decrement before memory is possibly returned.
693 		 */
694 		atomic_dec(&chip->active);
695 		if (!chip->num_interfaces)
696 			snd_card_free(chip->card);
697 	}
698 	mutex_unlock(&register_mutex);
699 	return err;
700 }
701 
702 /*
703  * we need to take care of counter, since disconnection can be called also
704  * many times as well as usb_audio_probe().
705  */
706 static void usb_audio_disconnect(struct usb_interface *intf)
707 {
708 	struct snd_usb_audio *chip = usb_get_intfdata(intf);
709 	struct snd_card *card;
710 	struct list_head *p;
711 
712 	if (chip == (void *)-1L)
713 		return;
714 
715 	card = chip->card;
716 
717 	mutex_lock(&register_mutex);
718 	if (atomic_inc_return(&chip->shutdown) == 1) {
719 		struct snd_usb_stream *as;
720 		struct snd_usb_endpoint *ep;
721 		struct usb_mixer_interface *mixer;
722 
723 		/* wait until all pending tasks done;
724 		 * they are protected by snd_usb_lock_shutdown()
725 		 */
726 		wait_event(chip->shutdown_wait,
727 			   !atomic_read(&chip->usage_count));
728 		snd_card_disconnect(card);
729 		/* release the pcm resources */
730 		list_for_each_entry(as, &chip->pcm_list, list) {
731 			snd_usb_stream_disconnect(as);
732 		}
733 		/* release the endpoint resources */
734 		list_for_each_entry(ep, &chip->ep_list, list) {
735 			snd_usb_endpoint_release(ep);
736 		}
737 		/* release the midi resources */
738 		list_for_each(p, &chip->midi_list) {
739 			snd_usbmidi_disconnect(p);
740 		}
741 		/*
742 		 * Nice to check quirk && quirk->shares_media_device and
743 		 * then call the snd_media_device_delete(). Don't have
744 		 * access to the quirk here. snd_media_device_delete()
745 		 * accesses mixer_list
746 		 */
747 		snd_media_device_delete(chip);
748 
749 		/* release mixer resources */
750 		list_for_each_entry(mixer, &chip->mixer_list, list) {
751 			snd_usb_mixer_disconnect(mixer);
752 		}
753 	}
754 
755 	chip->num_interfaces--;
756 	if (chip->num_interfaces <= 0) {
757 		usb_chip[chip->index] = NULL;
758 		mutex_unlock(&register_mutex);
759 		snd_card_free_when_closed(card);
760 	} else {
761 		mutex_unlock(&register_mutex);
762 	}
763 }
764 
765 /* lock the shutdown (disconnect) task and autoresume */
766 int snd_usb_lock_shutdown(struct snd_usb_audio *chip)
767 {
768 	int err;
769 
770 	atomic_inc(&chip->usage_count);
771 	if (atomic_read(&chip->shutdown)) {
772 		err = -EIO;
773 		goto error;
774 	}
775 	err = snd_usb_autoresume(chip);
776 	if (err < 0)
777 		goto error;
778 	return 0;
779 
780  error:
781 	if (atomic_dec_and_test(&chip->usage_count))
782 		wake_up(&chip->shutdown_wait);
783 	return err;
784 }
785 
786 /* autosuspend and unlock the shutdown */
787 void snd_usb_unlock_shutdown(struct snd_usb_audio *chip)
788 {
789 	snd_usb_autosuspend(chip);
790 	if (atomic_dec_and_test(&chip->usage_count))
791 		wake_up(&chip->shutdown_wait);
792 }
793 
794 #ifdef CONFIG_PM
795 
796 int snd_usb_autoresume(struct snd_usb_audio *chip)
797 {
798 	if (atomic_read(&chip->shutdown))
799 		return -EIO;
800 	if (atomic_inc_return(&chip->active) == 1)
801 		return usb_autopm_get_interface(chip->pm_intf);
802 	return 0;
803 }
804 
805 void snd_usb_autosuspend(struct snd_usb_audio *chip)
806 {
807 	if (atomic_read(&chip->shutdown))
808 		return;
809 	if (atomic_dec_and_test(&chip->active))
810 		usb_autopm_put_interface(chip->pm_intf);
811 }
812 
813 static int usb_audio_suspend(struct usb_interface *intf, pm_message_t message)
814 {
815 	struct snd_usb_audio *chip = usb_get_intfdata(intf);
816 	struct snd_usb_stream *as;
817 	struct usb_mixer_interface *mixer;
818 	struct list_head *p;
819 
820 	if (chip == (void *)-1L)
821 		return 0;
822 
823 	chip->autosuspended = !!PMSG_IS_AUTO(message);
824 	if (!chip->autosuspended)
825 		snd_power_change_state(chip->card, SNDRV_CTL_POWER_D3hot);
826 	if (!chip->num_suspended_intf++) {
827 		list_for_each_entry(as, &chip->pcm_list, list) {
828 			snd_usb_pcm_suspend(as);
829 			as->substream[0].need_setup_ep =
830 				as->substream[1].need_setup_ep = true;
831 		}
832 		list_for_each(p, &chip->midi_list)
833 			snd_usbmidi_suspend(p);
834 		list_for_each_entry(mixer, &chip->mixer_list, list)
835 			snd_usb_mixer_suspend(mixer);
836 	}
837 
838 	return 0;
839 }
840 
841 static int __usb_audio_resume(struct usb_interface *intf, bool reset_resume)
842 {
843 	struct snd_usb_audio *chip = usb_get_intfdata(intf);
844 	struct snd_usb_stream *as;
845 	struct usb_mixer_interface *mixer;
846 	struct list_head *p;
847 	int err = 0;
848 
849 	if (chip == (void *)-1L)
850 		return 0;
851 	if (--chip->num_suspended_intf)
852 		return 0;
853 
854 	atomic_inc(&chip->active); /* avoid autopm */
855 
856 	list_for_each_entry(as, &chip->pcm_list, list) {
857 		err = snd_usb_pcm_resume(as);
858 		if (err < 0)
859 			goto err_out;
860 	}
861 
862 	/*
863 	 * ALSA leaves material resumption to user space
864 	 * we just notify and restart the mixers
865 	 */
866 	list_for_each_entry(mixer, &chip->mixer_list, list) {
867 		err = snd_usb_mixer_resume(mixer, reset_resume);
868 		if (err < 0)
869 			goto err_out;
870 	}
871 
872 	list_for_each(p, &chip->midi_list) {
873 		snd_usbmidi_resume(p);
874 	}
875 
876 	if (!chip->autosuspended)
877 		snd_power_change_state(chip->card, SNDRV_CTL_POWER_D0);
878 	chip->autosuspended = 0;
879 
880 err_out:
881 	atomic_dec(&chip->active); /* allow autopm after this point */
882 	return err;
883 }
884 
885 static int usb_audio_resume(struct usb_interface *intf)
886 {
887 	return __usb_audio_resume(intf, false);
888 }
889 
890 static int usb_audio_reset_resume(struct usb_interface *intf)
891 {
892 	return __usb_audio_resume(intf, true);
893 }
894 #else
895 #define usb_audio_suspend	NULL
896 #define usb_audio_resume	NULL
897 #define usb_audio_reset_resume	NULL
898 #endif		/* CONFIG_PM */
899 
900 static const struct usb_device_id usb_audio_ids [] = {
901 #include "quirks-table.h"
902     { .match_flags = (USB_DEVICE_ID_MATCH_INT_CLASS | USB_DEVICE_ID_MATCH_INT_SUBCLASS),
903       .bInterfaceClass = USB_CLASS_AUDIO,
904       .bInterfaceSubClass = USB_SUBCLASS_AUDIOCONTROL },
905     { }						/* Terminating entry */
906 };
907 MODULE_DEVICE_TABLE(usb, usb_audio_ids);
908 
909 /*
910  * entry point for linux usb interface
911  */
912 
913 static struct usb_driver usb_audio_driver = {
914 	.name =		"snd-usb-audio",
915 	.probe =	usb_audio_probe,
916 	.disconnect =	usb_audio_disconnect,
917 	.suspend =	usb_audio_suspend,
918 	.resume =	usb_audio_resume,
919 	.reset_resume =	usb_audio_reset_resume,
920 	.id_table =	usb_audio_ids,
921 	.supports_autosuspend = 1,
922 };
923 
924 module_usb_driver(usb_audio_driver);
925