Merge branch 'pm-runtime' into pm-for-linus
[linux-2.6.git] / sound / usb / card.c
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  *   - async unlink should be used for avoiding the sleep inside lock.
29  *     2.4.22 usb-uhci seems buggy for async unlinking and results in
30  *     oops.  in such a cse, pass async_unlink=0 option.
31  *   - the linked URBs would be preferred but not used so far because of
32  *     the instability of unlinking.
33  *   - type II is not supported properly.  there is no device which supports
34  *     this type *correctly*.  SB extigy looks as if it supports, but it's
35  *     indeed an AC3 stream packed in SPDIF frames (i.e. no real AC3 stream).
36  */
37
38
39 #include <linux/bitops.h>
40 #include <linux/init.h>
41 #include <linux/list.h>
42 #include <linux/slab.h>
43 #include <linux/string.h>
44 #include <linux/ctype.h>
45 #include <linux/usb.h>
46 #include <linux/moduleparam.h>
47 #include <linux/mutex.h>
48 #include <linux/usb/audio.h>
49 #include <linux/usb/audio-v2.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 "urb.h"
69 #include "format.h"
70 #include "power.h"
71
72 MODULE_AUTHOR("Takashi Iwai <tiwai@suse.de>");
73 MODULE_DESCRIPTION("USB Audio");
74 MODULE_LICENSE("GPL");
75 MODULE_SUPPORTED_DEVICE("{{Generic,USB Audio}}");
76
77
78 static int index[SNDRV_CARDS] = SNDRV_DEFAULT_IDX;      /* Index 0-MAX */
79 static char *id[SNDRV_CARDS] = SNDRV_DEFAULT_STR;       /* ID for this card */
80 static int enable[SNDRV_CARDS] = SNDRV_DEFAULT_ENABLE_PNP;/* Enable this card */
81 /* Vendor/product IDs for this card */
82 static int vid[SNDRV_CARDS] = { [0 ... (SNDRV_CARDS-1)] = -1 };
83 static int pid[SNDRV_CARDS] = { [0 ... (SNDRV_CARDS-1)] = -1 };
84 static int nrpacks = 8;         /* max. number of packets per urb */
85 static int async_unlink = 1;
86 static int device_setup[SNDRV_CARDS]; /* device parameter for this card */
87 static int ignore_ctl_error;
88
89 module_param_array(index, int, NULL, 0444);
90 MODULE_PARM_DESC(index, "Index value for the USB audio adapter.");
91 module_param_array(id, charp, NULL, 0444);
92 MODULE_PARM_DESC(id, "ID string for the USB audio adapter.");
93 module_param_array(enable, bool, NULL, 0444);
94 MODULE_PARM_DESC(enable, "Enable USB audio adapter.");
95 module_param_array(vid, int, NULL, 0444);
96 MODULE_PARM_DESC(vid, "Vendor ID for the USB audio device.");
97 module_param_array(pid, int, NULL, 0444);
98 MODULE_PARM_DESC(pid, "Product ID for the USB audio device.");
99 module_param(nrpacks, int, 0644);
100 MODULE_PARM_DESC(nrpacks, "Max. number of packets per URB.");
101 module_param(async_unlink, bool, 0444);
102 MODULE_PARM_DESC(async_unlink, "Use async unlink mode.");
103 module_param_array(device_setup, int, NULL, 0444);
104 MODULE_PARM_DESC(device_setup, "Specific device setup (if needed).");
105 module_param(ignore_ctl_error, bool, 0444);
106 MODULE_PARM_DESC(ignore_ctl_error,
107                  "Ignore errors from USB controller for mixer interfaces.");
108
109 /*
110  * we keep the snd_usb_audio_t instances by ourselves for merging
111  * the all interfaces on the same card as one sound device.
112  */
113
114 static DEFINE_MUTEX(register_mutex);
115 static struct snd_usb_audio *usb_chip[SNDRV_CARDS];
116 static struct usb_driver usb_audio_driver;
117
118 /*
119  * disconnect streams
120  * called from snd_usb_audio_disconnect()
121  */
122 static void snd_usb_stream_disconnect(struct list_head *head)
123 {
124         int idx;
125         struct snd_usb_stream *as;
126         struct snd_usb_substream *subs;
127
128         as = list_entry(head, struct snd_usb_stream, list);
129         for (idx = 0; idx < 2; idx++) {
130                 subs = &as->substream[idx];
131                 if (!subs->num_formats)
132                         continue;
133                 snd_usb_release_substream_urbs(subs, 1);
134                 subs->interface = -1;
135         }
136 }
137
138 static int snd_usb_create_stream(struct snd_usb_audio *chip, int ctrlif, int interface)
139 {
140         struct usb_device *dev = chip->dev;
141         struct usb_host_interface *alts;
142         struct usb_interface_descriptor *altsd;
143         struct usb_interface *iface = usb_ifnum_to_if(dev, interface);
144
145         if (!iface) {
146                 snd_printk(KERN_ERR "%d:%u:%d : does not exist\n",
147                            dev->devnum, ctrlif, interface);
148                 return -EINVAL;
149         }
150
151         if (usb_interface_claimed(iface)) {
152                 snd_printdd(KERN_INFO "%d:%d:%d: skipping, already claimed\n",
153                                                 dev->devnum, ctrlif, interface);
154                 return -EINVAL;
155         }
156
157         alts = &iface->altsetting[0];
158         altsd = get_iface_desc(alts);
159         if ((altsd->bInterfaceClass == USB_CLASS_AUDIO ||
160              altsd->bInterfaceClass == USB_CLASS_VENDOR_SPEC) &&
161             altsd->bInterfaceSubClass == USB_SUBCLASS_MIDISTREAMING) {
162                 int err = snd_usbmidi_create(chip->card, iface,
163                                              &chip->midi_list, NULL);
164                 if (err < 0) {
165                         snd_printk(KERN_ERR "%d:%u:%d: cannot create sequencer device\n",
166                                                 dev->devnum, ctrlif, interface);
167                         return -EINVAL;
168                 }
169                 usb_driver_claim_interface(&usb_audio_driver, iface, (void *)-1L);
170
171                 return 0;
172         }
173
174         if ((altsd->bInterfaceClass != USB_CLASS_AUDIO &&
175              altsd->bInterfaceClass != USB_CLASS_VENDOR_SPEC) ||
176             altsd->bInterfaceSubClass != USB_SUBCLASS_AUDIOSTREAMING) {
177                 snd_printdd(KERN_ERR "%d:%u:%d: skipping non-supported interface %d\n",
178                                         dev->devnum, ctrlif, interface, altsd->bInterfaceClass);
179                 /* skip non-supported classes */
180                 return -EINVAL;
181         }
182
183         if (snd_usb_get_speed(dev) == USB_SPEED_LOW) {
184                 snd_printk(KERN_ERR "low speed audio streaming not supported\n");
185                 return -EINVAL;
186         }
187
188         if (! snd_usb_parse_audio_endpoints(chip, interface)) {
189                 usb_set_interface(dev, interface, 0); /* reset the current interface */
190                 usb_driver_claim_interface(&usb_audio_driver, iface, (void *)-1L);
191                 return -EINVAL;
192         }
193
194         return 0;
195 }
196
197 /*
198  * parse audio control descriptor and create pcm/midi streams
199  */
200 static int snd_usb_create_streams(struct snd_usb_audio *chip, int ctrlif)
201 {
202         struct usb_device *dev = chip->dev;
203         struct usb_host_interface *host_iface;
204         struct usb_interface_descriptor *altsd;
205         void *control_header;
206         int i, protocol;
207
208         /* find audiocontrol interface */
209         host_iface = &usb_ifnum_to_if(dev, ctrlif)->altsetting[0];
210         control_header = snd_usb_find_csint_desc(host_iface->extra,
211                                                  host_iface->extralen,
212                                                  NULL, UAC_HEADER);
213         altsd = get_iface_desc(host_iface);
214         protocol = altsd->bInterfaceProtocol;
215
216         if (!control_header) {
217                 snd_printk(KERN_ERR "cannot find UAC_HEADER\n");
218                 return -EINVAL;
219         }
220
221         switch (protocol) {
222         default:
223                 snd_printdd(KERN_WARNING "unknown interface protocol %#02x, assuming v1\n",
224                             protocol);
225                 /* fall through */
226
227         case UAC_VERSION_1: {
228                 struct uac1_ac_header_descriptor *h1 = control_header;
229
230                 if (!h1->bInCollection) {
231                         snd_printk(KERN_INFO "skipping empty audio interface (v1)\n");
232                         return -EINVAL;
233                 }
234
235                 if (h1->bLength < sizeof(*h1) + h1->bInCollection) {
236                         snd_printk(KERN_ERR "invalid UAC_HEADER (v1)\n");
237                         return -EINVAL;
238                 }
239
240                 for (i = 0; i < h1->bInCollection; i++)
241                         snd_usb_create_stream(chip, ctrlif, h1->baInterfaceNr[i]);
242
243                 break;
244         }
245
246         case UAC_VERSION_2: {
247                 struct usb_interface_assoc_descriptor *assoc =
248                         usb_ifnum_to_if(dev, ctrlif)->intf_assoc;
249
250                 if (!assoc) {
251                         snd_printk(KERN_ERR "Audio class v2 interfaces need an interface association\n");
252                         return -EINVAL;
253                 }
254
255                 for (i = 0; i < assoc->bInterfaceCount; i++) {
256                         int intf = assoc->bFirstInterface + i;
257
258                         if (intf != ctrlif)
259                                 snd_usb_create_stream(chip, ctrlif, intf);
260                 }
261
262                 break;
263         }
264         }
265
266         return 0;
267 }
268
269 /*
270  * free the chip instance
271  *
272  * here we have to do not much, since pcm and controls are already freed
273  *
274  */
275
276 static int snd_usb_audio_free(struct snd_usb_audio *chip)
277 {
278         kfree(chip);
279         return 0;
280 }
281
282 static int snd_usb_audio_dev_free(struct snd_device *device)
283 {
284         struct snd_usb_audio *chip = device->device_data;
285         return snd_usb_audio_free(chip);
286 }
287
288 static void remove_trailing_spaces(char *str)
289 {
290         char *p;
291
292         if (!*str)
293                 return;
294         for (p = str + strlen(str) - 1; p >= str && isspace(*p); p--)
295                 *p = 0;
296 }
297
298 /*
299  * create a chip instance and set its names.
300  */
301 static int snd_usb_audio_create(struct usb_device *dev, int idx,
302                                 const struct snd_usb_audio_quirk *quirk,
303                                 struct snd_usb_audio **rchip)
304 {
305         struct snd_card *card;
306         struct snd_usb_audio *chip;
307         int err, len;
308         char component[14];
309         static struct snd_device_ops ops = {
310                 .dev_free =     snd_usb_audio_dev_free,
311         };
312
313         *rchip = NULL;
314
315         switch (snd_usb_get_speed(dev)) {
316         case USB_SPEED_LOW:
317         case USB_SPEED_FULL:
318         case USB_SPEED_HIGH:
319         case USB_SPEED_SUPER:
320                 break;
321         default:
322                 snd_printk(KERN_ERR "unknown device speed %d\n", snd_usb_get_speed(dev));
323                 return -ENXIO;
324         }
325
326         err = snd_card_create(index[idx], id[idx], THIS_MODULE, 0, &card);
327         if (err < 0) {
328                 snd_printk(KERN_ERR "cannot create card instance %d\n", idx);
329                 return err;
330         }
331
332         chip = kzalloc(sizeof(*chip), GFP_KERNEL);
333         if (! chip) {
334                 snd_card_free(card);
335                 return -ENOMEM;
336         }
337
338         mutex_init(&chip->shutdown_mutex);
339         chip->index = idx;
340         chip->dev = dev;
341         chip->card = card;
342         chip->setup = device_setup[idx];
343         chip->nrpacks = nrpacks;
344         chip->async_unlink = async_unlink;
345         chip->probing = 1;
346
347         chip->usb_id = USB_ID(le16_to_cpu(dev->descriptor.idVendor),
348                               le16_to_cpu(dev->descriptor.idProduct));
349         INIT_LIST_HEAD(&chip->pcm_list);
350         INIT_LIST_HEAD(&chip->midi_list);
351         INIT_LIST_HEAD(&chip->mixer_list);
352
353         if ((err = snd_device_new(card, SNDRV_DEV_LOWLEVEL, chip, &ops)) < 0) {
354                 snd_usb_audio_free(chip);
355                 snd_card_free(card);
356                 return err;
357         }
358
359         strcpy(card->driver, "USB-Audio");
360         sprintf(component, "USB%04x:%04x",
361                 USB_ID_VENDOR(chip->usb_id), USB_ID_PRODUCT(chip->usb_id));
362         snd_component_add(card, component);
363
364         /* retrieve the device string as shortname */
365         if (quirk && quirk->product_name && *quirk->product_name) {
366                 strlcpy(card->shortname, quirk->product_name, sizeof(card->shortname));
367         } else {
368                 if (!dev->descriptor.iProduct ||
369                     usb_string(dev, dev->descriptor.iProduct,
370                     card->shortname, sizeof(card->shortname)) <= 0) {
371                         /* no name available from anywhere, so use ID */
372                         sprintf(card->shortname, "USB Device %#04x:%#04x",
373                                 USB_ID_VENDOR(chip->usb_id),
374                                 USB_ID_PRODUCT(chip->usb_id));
375                 }
376         }
377         remove_trailing_spaces(card->shortname);
378
379         /* retrieve the vendor and device strings as longname */
380         if (quirk && quirk->vendor_name && *quirk->vendor_name) {
381                 len = strlcpy(card->longname, quirk->vendor_name, sizeof(card->longname));
382         } else {
383                 if (dev->descriptor.iManufacturer)
384                         len = usb_string(dev, dev->descriptor.iManufacturer,
385                                          card->longname, sizeof(card->longname));
386                 else
387                         len = 0;
388                 /* we don't really care if there isn't any vendor string */
389         }
390         if (len > 0) {
391                 remove_trailing_spaces(card->longname);
392                 if (*card->longname)
393                         strlcat(card->longname, " ", sizeof(card->longname));
394         }
395
396         strlcat(card->longname, card->shortname, sizeof(card->longname));
397
398         len = strlcat(card->longname, " at ", sizeof(card->longname));
399
400         if (len < sizeof(card->longname))
401                 usb_make_path(dev, card->longname + len, sizeof(card->longname) - len);
402
403         switch (snd_usb_get_speed(dev)) {
404         case USB_SPEED_LOW:
405                 strlcat(card->longname, ", low speed", sizeof(card->longname));
406                 break;
407         case USB_SPEED_FULL:
408                 strlcat(card->longname, ", full speed", sizeof(card->longname));
409                 break;
410         case USB_SPEED_HIGH:
411                 strlcat(card->longname, ", high speed", sizeof(card->longname));
412                 break;
413         case USB_SPEED_SUPER:
414                 strlcat(card->longname, ", super speed", sizeof(card->longname));
415                 break;
416         default:
417                 break;
418         }
419
420         snd_usb_audio_create_proc(chip);
421
422         *rchip = chip;
423         return 0;
424 }
425
426 /*
427  * probe the active usb device
428  *
429  * note that this can be called multiple times per a device, when it
430  * includes multiple audio control interfaces.
431  *
432  * thus we check the usb device pointer and creates the card instance
433  * only at the first time.  the successive calls of this function will
434  * append the pcm interface to the corresponding card.
435  */
436 static struct snd_usb_audio *
437 snd_usb_audio_probe(struct usb_device *dev,
438                     struct usb_interface *intf,
439                     const struct usb_device_id *usb_id)
440 {
441         const struct snd_usb_audio_quirk *quirk = (const struct snd_usb_audio_quirk *)usb_id->driver_info;
442         int i, err;
443         struct snd_usb_audio *chip;
444         struct usb_host_interface *alts;
445         int ifnum;
446         u32 id;
447
448         alts = &intf->altsetting[0];
449         ifnum = get_iface_desc(alts)->bInterfaceNumber;
450         id = USB_ID(le16_to_cpu(dev->descriptor.idVendor),
451                     le16_to_cpu(dev->descriptor.idProduct));
452         if (quirk && quirk->ifnum >= 0 && ifnum != quirk->ifnum)
453                 goto __err_val;
454
455         if (snd_usb_apply_boot_quirk(dev, intf, quirk) < 0)
456                 goto __err_val;
457
458         /*
459          * found a config.  now register to ALSA
460          */
461
462         /* check whether it's already registered */
463         chip = NULL;
464         mutex_lock(&register_mutex);
465         for (i = 0; i < SNDRV_CARDS; i++) {
466                 if (usb_chip[i] && usb_chip[i]->dev == dev) {
467                         if (usb_chip[i]->shutdown) {
468                                 snd_printk(KERN_ERR "USB device is in the shutdown state, cannot create a card instance\n");
469                                 goto __error;
470                         }
471                         chip = usb_chip[i];
472                         chip->probing = 1;
473                         break;
474                 }
475         }
476         if (! chip) {
477                 /* it's a fresh one.
478                  * now look for an empty slot and create a new card instance
479                  */
480                 for (i = 0; i < SNDRV_CARDS; i++)
481                         if (enable[i] && ! usb_chip[i] &&
482                             (vid[i] == -1 || vid[i] == USB_ID_VENDOR(id)) &&
483                             (pid[i] == -1 || pid[i] == USB_ID_PRODUCT(id))) {
484                                 if (snd_usb_audio_create(dev, i, quirk, &chip) < 0) {
485                                         goto __error;
486                                 }
487                                 snd_card_set_dev(chip->card, &intf->dev);
488                                 chip->pm_intf = intf;
489                                 break;
490                         }
491                 if (!chip) {
492                         printk(KERN_ERR "no available usb audio device\n");
493                         goto __error;
494                 }
495         }
496
497         /*
498          * For devices with more than one control interface, we assume the
499          * first contains the audio controls. We might need a more specific
500          * check here in the future.
501          */
502         if (!chip->ctrl_intf)
503                 chip->ctrl_intf = alts;
504
505         chip->txfr_quirk = 0;
506         err = 1; /* continue */
507         if (quirk && quirk->ifnum != QUIRK_NO_INTERFACE) {
508                 /* need some special handlings */
509                 if ((err = snd_usb_create_quirk(chip, intf, &usb_audio_driver, quirk)) < 0)
510                         goto __error;
511         }
512
513         if (err > 0) {
514                 /* create normal USB audio interfaces */
515                 if (snd_usb_create_streams(chip, ifnum) < 0 ||
516                     snd_usb_create_mixer(chip, ifnum, ignore_ctl_error) < 0) {
517                         goto __error;
518                 }
519         }
520
521         /* we are allowed to call snd_card_register() many times */
522         if (snd_card_register(chip->card) < 0) {
523                 goto __error;
524         }
525
526         usb_chip[chip->index] = chip;
527         chip->num_interfaces++;
528         chip->probing = 0;
529         mutex_unlock(&register_mutex);
530         return chip;
531
532  __error:
533         if (chip) {
534                 if (!chip->num_interfaces)
535                         snd_card_free(chip->card);
536                 chip->probing = 0;
537         }
538         mutex_unlock(&register_mutex);
539  __err_val:
540         return NULL;
541 }
542
543 /*
544  * we need to take care of counter, since disconnection can be called also
545  * many times as well as usb_audio_probe().
546  */
547 static void snd_usb_audio_disconnect(struct usb_device *dev,
548                                      struct snd_usb_audio *chip)
549 {
550         struct snd_card *card;
551         struct list_head *p;
552
553         if (chip == (void *)-1L)
554                 return;
555
556         card = chip->card;
557         mutex_lock(&register_mutex);
558         mutex_lock(&chip->shutdown_mutex);
559         chip->shutdown = 1;
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 midi resources */
568                 list_for_each(p, &chip->midi_list) {
569                         snd_usbmidi_disconnect(p);
570                 }
571                 /* release mixer resources */
572                 list_for_each(p, &chip->mixer_list) {
573                         snd_usb_mixer_disconnect(p);
574                 }
575                 usb_chip[chip->index] = NULL;
576                 mutex_unlock(&chip->shutdown_mutex);
577                 mutex_unlock(&register_mutex);
578                 snd_card_free_when_closed(card);
579         } else {
580                 mutex_unlock(&chip->shutdown_mutex);
581                 mutex_unlock(&register_mutex);
582         }
583 }
584
585 /*
586  * new 2.5 USB kernel API
587  */
588 static int usb_audio_probe(struct usb_interface *intf,
589                            const struct usb_device_id *id)
590 {
591         struct snd_usb_audio *chip;
592         chip = snd_usb_audio_probe(interface_to_usbdev(intf), intf, id);
593         if (chip) {
594                 usb_set_intfdata(intf, chip);
595                 return 0;
596         } else
597                 return -EIO;
598 }
599
600 static void usb_audio_disconnect(struct usb_interface *intf)
601 {
602         snd_usb_audio_disconnect(interface_to_usbdev(intf),
603                                  usb_get_intfdata(intf));
604 }
605
606 #ifdef CONFIG_PM
607
608 int snd_usb_autoresume(struct snd_usb_audio *chip)
609 {
610         int err = -ENODEV;
611
612         if (!chip->shutdown && !chip->probing)
613                 err = usb_autopm_get_interface(chip->pm_intf);
614
615         return err;
616 }
617
618 void snd_usb_autosuspend(struct snd_usb_audio *chip)
619 {
620         if (!chip->shutdown && !chip->probing)
621                 usb_autopm_put_interface(chip->pm_intf);
622 }
623
624 static int usb_audio_suspend(struct usb_interface *intf, pm_message_t message)
625 {
626         struct snd_usb_audio *chip = usb_get_intfdata(intf);
627         struct list_head *p;
628         struct snd_usb_stream *as;
629         struct usb_mixer_interface *mixer;
630
631         if (chip == (void *)-1L)
632                 return 0;
633
634         if (!PMSG_IS_AUTO(message)) {
635                 snd_power_change_state(chip->card, SNDRV_CTL_POWER_D3hot);
636                 if (!chip->num_suspended_intf++) {
637                         list_for_each(p, &chip->pcm_list) {
638                                 as = list_entry(p, struct snd_usb_stream, list);
639                                 snd_pcm_suspend_all(as->pcm);
640                         }
641                 }
642         } else {
643                 /*
644                  * otherwise we keep the rest of the system in the dark
645                  * to keep this transparent
646                  */
647                 if (!chip->num_suspended_intf++)
648                         chip->autosuspended = 1;
649         }
650
651         list_for_each_entry(mixer, &chip->mixer_list, list)
652                 snd_usb_mixer_inactivate(mixer);
653
654         return 0;
655 }
656
657 static int usb_audio_resume(struct usb_interface *intf)
658 {
659         struct snd_usb_audio *chip = usb_get_intfdata(intf);
660         struct usb_mixer_interface *mixer;
661         int err = 0;
662
663         if (chip == (void *)-1L)
664                 return 0;
665         if (--chip->num_suspended_intf)
666                 return 0;
667         /*
668          * ALSA leaves material resumption to user space
669          * we just notify and restart the mixers
670          */
671         list_for_each_entry(mixer, &chip->mixer_list, list) {
672                 err = snd_usb_mixer_activate(mixer);
673                 if (err < 0)
674                         goto err_out;
675         }
676
677         if (!chip->autosuspended)
678                 snd_power_change_state(chip->card, SNDRV_CTL_POWER_D0);
679         chip->autosuspended = 0;
680
681 err_out:
682         return err;
683 }
684 #else
685 #define usb_audio_suspend       NULL
686 #define usb_audio_resume        NULL
687 #endif          /* CONFIG_PM */
688
689 static struct usb_device_id usb_audio_ids [] = {
690 #include "quirks-table.h"
691     { .match_flags = (USB_DEVICE_ID_MATCH_INT_CLASS | USB_DEVICE_ID_MATCH_INT_SUBCLASS),
692       .bInterfaceClass = USB_CLASS_AUDIO,
693       .bInterfaceSubClass = USB_SUBCLASS_AUDIOCONTROL },
694     { }                                         /* Terminating entry */
695 };
696
697 MODULE_DEVICE_TABLE (usb, usb_audio_ids);
698
699 /*
700  * entry point for linux usb interface
701  */
702
703 static struct usb_driver usb_audio_driver = {
704         .name =         "snd-usb-audio",
705         .probe =        usb_audio_probe,
706         .disconnect =   usb_audio_disconnect,
707         .suspend =      usb_audio_suspend,
708         .resume =       usb_audio_resume,
709         .id_table =     usb_audio_ids,
710         .supports_autosuspend = 1,
711 };
712
713 static int __init snd_usb_audio_init(void)
714 {
715         if (nrpacks < 1 || nrpacks > MAX_PACKS) {
716                 printk(KERN_WARNING "invalid nrpacks value.\n");
717                 return -EINVAL;
718         }
719         return usb_register(&usb_audio_driver);
720 }
721
722 static void __exit snd_usb_audio_cleanup(void)
723 {
724         usb_deregister(&usb_audio_driver);
725 }
726
727 module_init(snd_usb_audio_init);
728 module_exit(snd_usb_audio_cleanup);