xref: /openbmc/linux/sound/usb/card.c (revision 14eae6e9)
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  *
11  *   This program is free software; you can redistribute it and/or modify
12  *   it under the terms of the GNU General Public License as published by
13  *   the Free Software Foundation; either version 2 of the License, or
14  *   (at your option) any later version.
15  *
16  *   This program is distributed in the hope that it will be useful,
17  *   but WITHOUT ANY WARRANTY; without even the implied warranty of
18  *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
19  *   GNU General Public License for more details.
20  *
21  *   You should have received a copy of the GNU General Public License
22  *   along with this program; if not, write to the Free Software
23  *   Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307 USA
24  *
25  *
26  *  NOTES:
27  *
28  *   - the linked URBs would be preferred but not used so far because of
29  *     the instability of unlinking.
30  *   - type II is not supported properly.  there is no device which supports
31  *     this type *correctly*.  SB extigy looks as if it supports, but it's
32  *     indeed an AC3 stream packed in SPDIF frames (i.e. no real AC3 stream).
33  */
34 
35 
36 #include <linux/bitops.h>
37 #include <linux/init.h>
38 #include <linux/list.h>
39 #include <linux/slab.h>
40 #include <linux/string.h>
41 #include <linux/ctype.h>
42 #include <linux/usb.h>
43 #include <linux/moduleparam.h>
44 #include <linux/mutex.h>
45 #include <linux/usb/audio.h>
46 #include <linux/usb/audio-v2.h>
47 #include <linux/module.h>
48 
49 #include <sound/control.h>
50 #include <sound/core.h>
51 #include <sound/info.h>
52 #include <sound/pcm.h>
53 #include <sound/pcm_params.h>
54 #include <sound/initval.h>
55 
56 #include "usbaudio.h"
57 #include "card.h"
58 #include "midi.h"
59 #include "mixer.h"
60 #include "proc.h"
61 #include "quirks.h"
62 #include "endpoint.h"
63 #include "helper.h"
64 #include "debug.h"
65 #include "pcm.h"
66 #include "format.h"
67 #include "power.h"
68 #include "stream.h"
69 
70 MODULE_AUTHOR("Takashi Iwai <tiwai@suse.de>");
71 MODULE_DESCRIPTION("USB Audio");
72 MODULE_LICENSE("GPL");
73 MODULE_SUPPORTED_DEVICE("{{Generic,USB Audio}}");
74 
75 
76 static int index[SNDRV_CARDS] = SNDRV_DEFAULT_IDX;	/* Index 0-MAX */
77 static char *id[SNDRV_CARDS] = SNDRV_DEFAULT_STR;	/* ID for this card */
78 static bool enable[SNDRV_CARDS] = SNDRV_DEFAULT_ENABLE_PNP;/* Enable this card */
79 /* Vendor/product IDs for this card */
80 static int vid[SNDRV_CARDS] = { [0 ... (SNDRV_CARDS-1)] = -1 };
81 static int pid[SNDRV_CARDS] = { [0 ... (SNDRV_CARDS-1)] = -1 };
82 static int nrpacks = 8;		/* max. number of packets per urb */
83 static int device_setup[SNDRV_CARDS]; /* device parameter for this card */
84 static bool ignore_ctl_error;
85 
86 module_param_array(index, int, NULL, 0444);
87 MODULE_PARM_DESC(index, "Index value for the USB audio adapter.");
88 module_param_array(id, charp, NULL, 0444);
89 MODULE_PARM_DESC(id, "ID string for the USB audio adapter.");
90 module_param_array(enable, bool, NULL, 0444);
91 MODULE_PARM_DESC(enable, "Enable USB audio adapter.");
92 module_param_array(vid, int, NULL, 0444);
93 MODULE_PARM_DESC(vid, "Vendor ID for the USB audio device.");
94 module_param_array(pid, int, NULL, 0444);
95 MODULE_PARM_DESC(pid, "Product ID for the USB audio device.");
96 module_param(nrpacks, int, 0644);
97 MODULE_PARM_DESC(nrpacks, "Max. number of packets per URB.");
98 module_param_array(device_setup, int, NULL, 0444);
99 MODULE_PARM_DESC(device_setup, "Specific device setup (if needed).");
100 module_param(ignore_ctl_error, bool, 0444);
101 MODULE_PARM_DESC(ignore_ctl_error,
102 		 "Ignore errors from USB controller for mixer interfaces.");
103 
104 /*
105  * we keep the snd_usb_audio_t instances by ourselves for merging
106  * the all interfaces on the same card as one sound device.
107  */
108 
109 static DEFINE_MUTEX(register_mutex);
110 static struct snd_usb_audio *usb_chip[SNDRV_CARDS];
111 static struct usb_driver usb_audio_driver;
112 
113 /*
114  * disconnect streams
115  * called from snd_usb_audio_disconnect()
116  */
117 static void snd_usb_stream_disconnect(struct list_head *head)
118 {
119 	int idx;
120 	struct snd_usb_stream *as;
121 	struct snd_usb_substream *subs;
122 
123 	as = list_entry(head, struct snd_usb_stream, list);
124 	for (idx = 0; idx < 2; idx++) {
125 		subs = &as->substream[idx];
126 		if (!subs->num_formats)
127 			continue;
128 		subs->interface = -1;
129 		subs->data_endpoint = NULL;
130 		subs->sync_endpoint = NULL;
131 	}
132 }
133 
134 static int snd_usb_create_stream(struct snd_usb_audio *chip, int ctrlif, int interface)
135 {
136 	struct usb_device *dev = chip->dev;
137 	struct usb_host_interface *alts;
138 	struct usb_interface_descriptor *altsd;
139 	struct usb_interface *iface = usb_ifnum_to_if(dev, interface);
140 
141 	if (!iface) {
142 		snd_printk(KERN_ERR "%d:%u:%d : does not exist\n",
143 			   dev->devnum, ctrlif, interface);
144 		return -EINVAL;
145 	}
146 
147 	if (usb_interface_claimed(iface)) {
148 		snd_printdd(KERN_INFO "%d:%d:%d: skipping, already claimed\n",
149 						dev->devnum, ctrlif, interface);
150 		return -EINVAL;
151 	}
152 
153 	alts = &iface->altsetting[0];
154 	altsd = get_iface_desc(alts);
155 	if ((altsd->bInterfaceClass == USB_CLASS_AUDIO ||
156 	     altsd->bInterfaceClass == USB_CLASS_VENDOR_SPEC) &&
157 	    altsd->bInterfaceSubClass == USB_SUBCLASS_MIDISTREAMING) {
158 		int err = snd_usbmidi_create(chip->card, iface,
159 					     &chip->midi_list, NULL);
160 		if (err < 0) {
161 			snd_printk(KERN_ERR "%d:%u:%d: cannot create sequencer device\n",
162 						dev->devnum, ctrlif, interface);
163 			return -EINVAL;
164 		}
165 		usb_driver_claim_interface(&usb_audio_driver, iface, (void *)-1L);
166 
167 		return 0;
168 	}
169 
170 	if ((altsd->bInterfaceClass != USB_CLASS_AUDIO &&
171 	     altsd->bInterfaceClass != USB_CLASS_VENDOR_SPEC) ||
172 	    altsd->bInterfaceSubClass != USB_SUBCLASS_AUDIOSTREAMING) {
173 		snd_printdd(KERN_ERR "%d:%u:%d: skipping non-supported interface %d\n",
174 					dev->devnum, ctrlif, interface, altsd->bInterfaceClass);
175 		/* skip non-supported classes */
176 		return -EINVAL;
177 	}
178 
179 	if (snd_usb_get_speed(dev) == USB_SPEED_LOW) {
180 		snd_printk(KERN_ERR "low speed audio streaming not supported\n");
181 		return -EINVAL;
182 	}
183 
184 	if (! snd_usb_parse_audio_interface(chip, interface)) {
185 		usb_set_interface(dev, interface, 0); /* reset the current interface */
186 		usb_driver_claim_interface(&usb_audio_driver, iface, (void *)-1L);
187 		return -EINVAL;
188 	}
189 
190 	return 0;
191 }
192 
193 /*
194  * parse audio control descriptor and create pcm/midi streams
195  */
196 static int snd_usb_create_streams(struct snd_usb_audio *chip, int ctrlif)
197 {
198 	struct usb_device *dev = chip->dev;
199 	struct usb_host_interface *host_iface;
200 	struct usb_interface_descriptor *altsd;
201 	void *control_header;
202 	int i, protocol;
203 
204 	/* find audiocontrol interface */
205 	host_iface = &usb_ifnum_to_if(dev, ctrlif)->altsetting[0];
206 	control_header = snd_usb_find_csint_desc(host_iface->extra,
207 						 host_iface->extralen,
208 						 NULL, UAC_HEADER);
209 	altsd = get_iface_desc(host_iface);
210 	protocol = altsd->bInterfaceProtocol;
211 
212 	if (!control_header) {
213 		snd_printk(KERN_ERR "cannot find UAC_HEADER\n");
214 		return -EINVAL;
215 	}
216 
217 	switch (protocol) {
218 	default:
219 		snd_printdd(KERN_WARNING "unknown interface protocol %#02x, assuming v1\n",
220 			    protocol);
221 		/* fall through */
222 
223 	case UAC_VERSION_1: {
224 		struct uac1_ac_header_descriptor *h1 = control_header;
225 
226 		if (!h1->bInCollection) {
227 			snd_printk(KERN_INFO "skipping empty audio interface (v1)\n");
228 			return -EINVAL;
229 		}
230 
231 		if (h1->bLength < sizeof(*h1) + h1->bInCollection) {
232 			snd_printk(KERN_ERR "invalid UAC_HEADER (v1)\n");
233 			return -EINVAL;
234 		}
235 
236 		for (i = 0; i < h1->bInCollection; i++)
237 			snd_usb_create_stream(chip, ctrlif, h1->baInterfaceNr[i]);
238 
239 		break;
240 	}
241 
242 	case UAC_VERSION_2: {
243 		struct usb_interface_assoc_descriptor *assoc =
244 			usb_ifnum_to_if(dev, ctrlif)->intf_assoc;
245 
246 		if (!assoc) {
247 			snd_printk(KERN_ERR "Audio class v2 interfaces need an interface association\n");
248 			return -EINVAL;
249 		}
250 
251 		for (i = 0; i < assoc->bInterfaceCount; i++) {
252 			int intf = assoc->bFirstInterface + i;
253 
254 			if (intf != ctrlif)
255 				snd_usb_create_stream(chip, ctrlif, intf);
256 		}
257 
258 		break;
259 	}
260 	}
261 
262 	return 0;
263 }
264 
265 /*
266  * free the chip instance
267  *
268  * here we have to do not much, since pcm and controls are already freed
269  *
270  */
271 
272 static int snd_usb_audio_free(struct snd_usb_audio *chip)
273 {
274 	mutex_destroy(&chip->mutex);
275 	kfree(chip);
276 	return 0;
277 }
278 
279 static int snd_usb_audio_dev_free(struct snd_device *device)
280 {
281 	struct snd_usb_audio *chip = device->device_data;
282 	return snd_usb_audio_free(chip);
283 }
284 
285 static void remove_trailing_spaces(char *str)
286 {
287 	char *p;
288 
289 	if (!*str)
290 		return;
291 	for (p = str + strlen(str) - 1; p >= str && isspace(*p); p--)
292 		*p = 0;
293 }
294 
295 /*
296  * create a chip instance and set its names.
297  */
298 static int snd_usb_audio_create(struct usb_device *dev, int idx,
299 				const struct snd_usb_audio_quirk *quirk,
300 				struct snd_usb_audio **rchip)
301 {
302 	struct snd_card *card;
303 	struct snd_usb_audio *chip;
304 	int err, len;
305 	char component[14];
306 	static struct snd_device_ops ops = {
307 		.dev_free =	snd_usb_audio_dev_free,
308 	};
309 
310 	*rchip = NULL;
311 
312 	switch (snd_usb_get_speed(dev)) {
313 	case USB_SPEED_LOW:
314 	case USB_SPEED_FULL:
315 	case USB_SPEED_HIGH:
316 	case USB_SPEED_SUPER:
317 		break;
318 	default:
319 		snd_printk(KERN_ERR "unknown device speed %d\n", snd_usb_get_speed(dev));
320 		return -ENXIO;
321 	}
322 
323 	err = snd_card_create(index[idx], id[idx], THIS_MODULE, 0, &card);
324 	if (err < 0) {
325 		snd_printk(KERN_ERR "cannot create card instance %d\n", idx);
326 		return err;
327 	}
328 
329 	chip = kzalloc(sizeof(*chip), GFP_KERNEL);
330 	if (! chip) {
331 		snd_card_free(card);
332 		return -ENOMEM;
333 	}
334 
335 	mutex_init(&chip->mutex);
336 	init_rwsem(&chip->shutdown_rwsem);
337 	chip->index = idx;
338 	chip->dev = dev;
339 	chip->card = card;
340 	chip->setup = device_setup[idx];
341 	chip->nrpacks = nrpacks;
342 	chip->probing = 1;
343 
344 	chip->usb_id = USB_ID(le16_to_cpu(dev->descriptor.idVendor),
345 			      le16_to_cpu(dev->descriptor.idProduct));
346 	INIT_LIST_HEAD(&chip->pcm_list);
347 	INIT_LIST_HEAD(&chip->ep_list);
348 	INIT_LIST_HEAD(&chip->midi_list);
349 	INIT_LIST_HEAD(&chip->mixer_list);
350 
351 	if ((err = snd_device_new(card, SNDRV_DEV_LOWLEVEL, chip, &ops)) < 0) {
352 		snd_usb_audio_free(chip);
353 		snd_card_free(card);
354 		return err;
355 	}
356 
357 	strcpy(card->driver, "USB-Audio");
358 	sprintf(component, "USB%04x:%04x",
359 		USB_ID_VENDOR(chip->usb_id), USB_ID_PRODUCT(chip->usb_id));
360 	snd_component_add(card, component);
361 
362 	/* retrieve the device string as shortname */
363 	if (quirk && quirk->product_name && *quirk->product_name) {
364 		strlcpy(card->shortname, quirk->product_name, sizeof(card->shortname));
365 	} else {
366 		if (!dev->descriptor.iProduct ||
367 		    usb_string(dev, dev->descriptor.iProduct,
368 		    card->shortname, sizeof(card->shortname)) <= 0) {
369 			/* no name available from anywhere, so use ID */
370 			sprintf(card->shortname, "USB Device %#04x:%#04x",
371 				USB_ID_VENDOR(chip->usb_id),
372 				USB_ID_PRODUCT(chip->usb_id));
373 		}
374 	}
375 	remove_trailing_spaces(card->shortname);
376 
377 	/* retrieve the vendor and device strings as longname */
378 	if (quirk && quirk->vendor_name && *quirk->vendor_name) {
379 		len = strlcpy(card->longname, quirk->vendor_name, sizeof(card->longname));
380 	} else {
381 		if (dev->descriptor.iManufacturer)
382 			len = usb_string(dev, dev->descriptor.iManufacturer,
383 					 card->longname, sizeof(card->longname));
384 		else
385 			len = 0;
386 		/* we don't really care if there isn't any vendor string */
387 	}
388 	if (len > 0) {
389 		remove_trailing_spaces(card->longname);
390 		if (*card->longname)
391 			strlcat(card->longname, " ", sizeof(card->longname));
392 	}
393 
394 	strlcat(card->longname, card->shortname, sizeof(card->longname));
395 
396 	len = strlcat(card->longname, " at ", sizeof(card->longname));
397 
398 	if (len < sizeof(card->longname))
399 		usb_make_path(dev, card->longname + len, sizeof(card->longname) - len);
400 
401 	switch (snd_usb_get_speed(dev)) {
402 	case USB_SPEED_LOW:
403 		strlcat(card->longname, ", low speed", sizeof(card->longname));
404 		break;
405 	case USB_SPEED_FULL:
406 		strlcat(card->longname, ", full speed", sizeof(card->longname));
407 		break;
408 	case USB_SPEED_HIGH:
409 		strlcat(card->longname, ", high speed", sizeof(card->longname));
410 		break;
411 	case USB_SPEED_SUPER:
412 		strlcat(card->longname, ", super speed", sizeof(card->longname));
413 		break;
414 	default:
415 		break;
416 	}
417 
418 	snd_usb_audio_create_proc(chip);
419 
420 	*rchip = chip;
421 	return 0;
422 }
423 
424 /*
425  * probe the active usb device
426  *
427  * note that this can be called multiple times per a device, when it
428  * includes multiple audio control interfaces.
429  *
430  * thus we check the usb device pointer and creates the card instance
431  * only at the first time.  the successive calls of this function will
432  * append the pcm interface to the corresponding card.
433  */
434 static struct snd_usb_audio *
435 snd_usb_audio_probe(struct usb_device *dev,
436 		    struct usb_interface *intf,
437 		    const struct usb_device_id *usb_id)
438 {
439 	const struct snd_usb_audio_quirk *quirk = (const struct snd_usb_audio_quirk *)usb_id->driver_info;
440 	int i, err;
441 	struct snd_usb_audio *chip;
442 	struct usb_host_interface *alts;
443 	int ifnum;
444 	u32 id;
445 
446 	alts = &intf->altsetting[0];
447 	ifnum = get_iface_desc(alts)->bInterfaceNumber;
448 	id = USB_ID(le16_to_cpu(dev->descriptor.idVendor),
449 		    le16_to_cpu(dev->descriptor.idProduct));
450 	if (quirk && quirk->ifnum >= 0 && ifnum != quirk->ifnum)
451 		goto __err_val;
452 
453 	if (snd_usb_apply_boot_quirk(dev, intf, quirk) < 0)
454 		goto __err_val;
455 
456 	/*
457 	 * found a config.  now register to ALSA
458 	 */
459 
460 	/* check whether it's already registered */
461 	chip = NULL;
462 	mutex_lock(&register_mutex);
463 	for (i = 0; i < SNDRV_CARDS; i++) {
464 		if (usb_chip[i] && usb_chip[i]->dev == dev) {
465 			if (usb_chip[i]->shutdown) {
466 				snd_printk(KERN_ERR "USB device is in the shutdown state, cannot create a card instance\n");
467 				goto __error;
468 			}
469 			chip = usb_chip[i];
470 			chip->probing = 1;
471 			break;
472 		}
473 	}
474 	if (! chip) {
475 		/* it's a fresh one.
476 		 * now look for an empty slot and create a new card instance
477 		 */
478 		for (i = 0; i < SNDRV_CARDS; i++)
479 			if (enable[i] && ! usb_chip[i] &&
480 			    (vid[i] == -1 || vid[i] == USB_ID_VENDOR(id)) &&
481 			    (pid[i] == -1 || pid[i] == USB_ID_PRODUCT(id))) {
482 				if (snd_usb_audio_create(dev, i, quirk, &chip) < 0) {
483 					goto __error;
484 				}
485 				snd_card_set_dev(chip->card, &intf->dev);
486 				chip->pm_intf = intf;
487 				break;
488 			}
489 		if (!chip) {
490 			printk(KERN_ERR "no available usb audio device\n");
491 			goto __error;
492 		}
493 	}
494 
495 	/*
496 	 * For devices with more than one control interface, we assume the
497 	 * first contains the audio controls. We might need a more specific
498 	 * check here in the future.
499 	 */
500 	if (!chip->ctrl_intf)
501 		chip->ctrl_intf = alts;
502 
503 	chip->txfr_quirk = 0;
504 	err = 1; /* continue */
505 	if (quirk && quirk->ifnum != QUIRK_NO_INTERFACE) {
506 		/* need some special handlings */
507 		if ((err = snd_usb_create_quirk(chip, intf, &usb_audio_driver, quirk)) < 0)
508 			goto __error;
509 	}
510 
511 	if (err > 0) {
512 		/* create normal USB audio interfaces */
513 		if (snd_usb_create_streams(chip, ifnum) < 0 ||
514 		    snd_usb_create_mixer(chip, ifnum, ignore_ctl_error) < 0) {
515 			goto __error;
516 		}
517 	}
518 
519 	/* we are allowed to call snd_card_register() many times */
520 	if (snd_card_register(chip->card) < 0) {
521 		goto __error;
522 	}
523 
524 	usb_chip[chip->index] = chip;
525 	chip->num_interfaces++;
526 	chip->probing = 0;
527 	mutex_unlock(&register_mutex);
528 	return chip;
529 
530  __error:
531 	if (chip) {
532 		if (!chip->num_interfaces)
533 			snd_card_free(chip->card);
534 		chip->probing = 0;
535 	}
536 	mutex_unlock(&register_mutex);
537  __err_val:
538 	return NULL;
539 }
540 
541 /*
542  * we need to take care of counter, since disconnection can be called also
543  * many times as well as usb_audio_probe().
544  */
545 static void snd_usb_audio_disconnect(struct usb_device *dev,
546 				     struct snd_usb_audio *chip)
547 {
548 	struct snd_card *card;
549 	struct list_head *p, *n;
550 
551 	if (chip == (void *)-1L)
552 		return;
553 
554 	card = chip->card;
555 	down_write(&chip->shutdown_rwsem);
556 	chip->shutdown = 1;
557 	up_write(&chip->shutdown_rwsem);
558 
559 	mutex_lock(&register_mutex);
560 	chip->num_interfaces--;
561 	if (chip->num_interfaces <= 0) {
562 		snd_card_disconnect(card);
563 		/* release the pcm resources */
564 		list_for_each(p, &chip->pcm_list) {
565 			snd_usb_stream_disconnect(p);
566 		}
567 		/* release the endpoint resources */
568 		list_for_each_safe(p, n, &chip->ep_list) {
569 			snd_usb_endpoint_free(p);
570 		}
571 		/* release the midi resources */
572 		list_for_each(p, &chip->midi_list) {
573 			snd_usbmidi_disconnect(p);
574 		}
575 		/* release mixer resources */
576 		list_for_each(p, &chip->mixer_list) {
577 			snd_usb_mixer_disconnect(p);
578 		}
579 		usb_chip[chip->index] = NULL;
580 		mutex_unlock(&register_mutex);
581 		snd_card_free_when_closed(card);
582 	} else {
583 		mutex_unlock(&register_mutex);
584 	}
585 }
586 
587 /*
588  * new 2.5 USB kernel API
589  */
590 static int usb_audio_probe(struct usb_interface *intf,
591 			   const struct usb_device_id *id)
592 {
593 	struct snd_usb_audio *chip;
594 	chip = snd_usb_audio_probe(interface_to_usbdev(intf), intf, id);
595 	if (chip) {
596 		usb_set_intfdata(intf, chip);
597 		return 0;
598 	} else
599 		return -EIO;
600 }
601 
602 static void usb_audio_disconnect(struct usb_interface *intf)
603 {
604 	snd_usb_audio_disconnect(interface_to_usbdev(intf),
605 				 usb_get_intfdata(intf));
606 }
607 
608 #ifdef CONFIG_PM
609 
610 int snd_usb_autoresume(struct snd_usb_audio *chip)
611 {
612 	int err = -ENODEV;
613 
614 	down_read(&chip->shutdown_rwsem);
615 	if (!chip->shutdown && !chip->probing)
616 		err = usb_autopm_get_interface(chip->pm_intf);
617 	up_read(&chip->shutdown_rwsem);
618 
619 	return err;
620 }
621 
622 void snd_usb_autosuspend(struct snd_usb_audio *chip)
623 {
624 	down_read(&chip->shutdown_rwsem);
625 	if (!chip->shutdown && !chip->probing)
626 		usb_autopm_put_interface(chip->pm_intf);
627 	up_read(&chip->shutdown_rwsem);
628 }
629 
630 static int usb_audio_suspend(struct usb_interface *intf, pm_message_t message)
631 {
632 	struct snd_usb_audio *chip = usb_get_intfdata(intf);
633 	struct list_head *p;
634 	struct snd_usb_stream *as;
635 	struct usb_mixer_interface *mixer;
636 
637 	if (chip == (void *)-1L)
638 		return 0;
639 
640 	if (!PMSG_IS_AUTO(message)) {
641 		snd_power_change_state(chip->card, SNDRV_CTL_POWER_D3hot);
642 		if (!chip->num_suspended_intf++) {
643 			list_for_each(p, &chip->pcm_list) {
644 				as = list_entry(p, struct snd_usb_stream, list);
645 				snd_pcm_suspend_all(as->pcm);
646 				as->substream[0].need_setup_ep =
647 					as->substream[1].need_setup_ep = true;
648 			}
649  		}
650 	} else {
651 		/*
652 		 * otherwise we keep the rest of the system in the dark
653 		 * to keep this transparent
654 		 */
655 		if (!chip->num_suspended_intf++)
656 			chip->autosuspended = 1;
657 	}
658 
659 	list_for_each_entry(mixer, &chip->mixer_list, list)
660 		snd_usb_mixer_inactivate(mixer);
661 
662 	return 0;
663 }
664 
665 static int usb_audio_resume(struct usb_interface *intf)
666 {
667 	struct snd_usb_audio *chip = usb_get_intfdata(intf);
668 	struct usb_mixer_interface *mixer;
669 	int err = 0;
670 
671 	if (chip == (void *)-1L)
672 		return 0;
673 	if (--chip->num_suspended_intf)
674 		return 0;
675 	/*
676 	 * ALSA leaves material resumption to user space
677 	 * we just notify and restart the mixers
678 	 */
679 	list_for_each_entry(mixer, &chip->mixer_list, list) {
680 		err = snd_usb_mixer_activate(mixer);
681 		if (err < 0)
682 			goto err_out;
683 	}
684 
685 	if (!chip->autosuspended)
686 		snd_power_change_state(chip->card, SNDRV_CTL_POWER_D0);
687 	chip->autosuspended = 0;
688 
689 err_out:
690 	return err;
691 }
692 #else
693 #define usb_audio_suspend	NULL
694 #define usb_audio_resume	NULL
695 #endif		/* CONFIG_PM */
696 
697 static struct usb_device_id usb_audio_ids [] = {
698 #include "quirks-table.h"
699     { .match_flags = (USB_DEVICE_ID_MATCH_INT_CLASS | USB_DEVICE_ID_MATCH_INT_SUBCLASS),
700       .bInterfaceClass = USB_CLASS_AUDIO,
701       .bInterfaceSubClass = USB_SUBCLASS_AUDIOCONTROL },
702     { }						/* Terminating entry */
703 };
704 
705 MODULE_DEVICE_TABLE (usb, usb_audio_ids);
706 
707 /*
708  * entry point for linux usb interface
709  */
710 
711 static struct usb_driver usb_audio_driver = {
712 	.name =		"snd-usb-audio",
713 	.probe =	usb_audio_probe,
714 	.disconnect =	usb_audio_disconnect,
715 	.suspend =	usb_audio_suspend,
716 	.resume =	usb_audio_resume,
717 	.id_table =	usb_audio_ids,
718 	.supports_autosuspend = 1,
719 };
720 
721 static int __init snd_usb_audio_init(void)
722 {
723 	if (nrpacks < 1 || nrpacks > MAX_PACKS) {
724 		printk(KERN_WARNING "invalid nrpacks value.\n");
725 		return -EINVAL;
726 	}
727 	return usb_register(&usb_audio_driver);
728 }
729 
730 static void __exit snd_usb_audio_cleanup(void)
731 {
732 	usb_deregister(&usb_audio_driver);
733 }
734 
735 module_init(snd_usb_audio_init);
736 module_exit(snd_usb_audio_cleanup);
737