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 && !chip->num_interfaces)
 534                 snd_card_free(chip->card);
 535         mutex_unlock(&register_mutex);
 536  __err_val:
 537         return NULL;
 538 }
 539
 540 /*
 541  * we need to take care of counter, since disconnection can be called also
 542  * many times as well as usb_audio_probe().
 543  */
 544 static void snd_usb_audio_disconnect(struct usb_device *dev,
 545                                      struct snd_usb_audio *chip)
 546 {
 547         struct snd_card *card;
 548         struct list_head *p;
 549
 550         if (chip == (void *)-1L)
 551                 return;
 552
 553         card = chip->card;
 554         mutex_lock(&register_mutex);
 555         mutex_lock(&chip->shutdown_mutex);
 556         chip->shutdown = 1;
 557         chip->num_interfaces--;
 558         if (chip->num_interfaces <= 0) {
 559                 snd_card_disconnect(card);
 560                 /* release the pcm resources */
 561                 list_for_each(p, &chip->pcm_list) {
 562                         snd_usb_stream_disconnect(p);
 563                 }
 564                 /* release the midi resources */
 565                 list_for_each(p, &chip->midi_list) {
 566                         snd_usbmidi_disconnect(p);
 567                 }
 568                 /* release mixer resources */
 569                 list_for_each(p, &chip->mixer_list) {
 570                         snd_usb_mixer_disconnect(p);
 571                 }
 572                 usb_chip[chip->index] = NULL;
 573                 mutex_unlock(&chip->shutdown_mutex);
 574                 mutex_unlock(&register_mutex);
 575                 snd_card_free_when_closed(card);
 576         } else {
 577                 mutex_unlock(&chip->shutdown_mutex);
 578                 mutex_unlock(&register_mutex);
 579         }
 580 }
 581
 582 /*
 583  * new 2.5 USB kernel API
 584  */
 585 static int usb_audio_probe(struct usb_interface *intf,
 586                            const struct usb_device_id *id)
 587 {
 588         struct snd_usb_audio *chip;
 589         chip = snd_usb_audio_probe(interface_to_usbdev(intf), intf, id);
 590         if (chip) {
 591                 usb_set_intfdata(intf, chip);
 592                 return 0;
 593         } else
 594                 return -EIO;
 595 }
 596
 597 static void usb_audio_disconnect(struct usb_interface *intf)
 598 {
 599         snd_usb_audio_disconnect(interface_to_usbdev(intf),
 600                                  usb_get_intfdata(intf));
 601 }
 602
 603 #ifdef CONFIG_PM
 604
 605 int snd_usb_autoresume(struct snd_usb_audio *chip)
 606 {
 607         int err = -ENODEV;
 608
 609         if (!chip->shutdown && !chip->probing)
 610                 err = usb_autopm_get_interface(chip->pm_intf);
 611
 612         return err;
 613 }
 614
 615 void snd_usb_autosuspend(struct snd_usb_audio *chip)
 616 {
 617         if (!chip->shutdown && !chip->probing)
 618                 usb_autopm_put_interface(chip->pm_intf);
 619 }
 620
 621 static int usb_audio_suspend(struct usb_interface *intf, pm_message_t message)
 622 {
 623         struct snd_usb_audio *chip = usb_get_intfdata(intf);
 624         struct list_head *p;
 625         struct snd_usb_stream *as;
 626         struct usb_mixer_interface *mixer;
 627
 628         if (chip == (void *)-1L)
 629                 return 0;
 630
 631         if (!(message.event & PM_EVENT_AUTO)) {
 632                 snd_power_change_state(chip->card, SNDRV_CTL_POWER_D3hot);
 633                 if (!chip->num_suspended_intf++) {
 634                         list_for_each(p, &chip->pcm_list) {
 635                                 as = list_entry(p, struct snd_usb_stream, list);
 636                                 snd_pcm_suspend_all(as->pcm);
 637                         }
 638                 }
 639         } else {
 640                 /*
 641                  * otherwise we keep the rest of the system in the dark
 642                  * to keep this transparent
 643                  */
 644                 if (!chip->num_suspended_intf++)
 645                         chip->autosuspended = 1;
 646         }
 647
 648         list_for_each_entry(mixer, &chip->mixer_list, list)
 649                 snd_usb_mixer_inactivate(mixer);
 650
 651         return 0;
 652 }
 653
 654 static int usb_audio_resume(struct usb_interface *intf)
 655 {
 656         struct snd_usb_audio *chip = usb_get_intfdata(intf);
 657         struct usb_mixer_interface *mixer;
 658         int err = 0;
 659
 660         if (chip == (void *)-1L)
 661                 return 0;
 662         if (--chip->num_suspended_intf)
 663                 return 0;
 664         /*
 665          * ALSA leaves material resumption to user space
 666          * we just notify and restart the mixers
 667          */
 668         list_for_each_entry(mixer, &chip->mixer_list, list) {
 669                 err = snd_usb_mixer_activate(mixer);
 670                 if (err < 0)
 671                         goto err_out;
 672         }
 673
 674         if (!chip->autosuspended)
 675                 snd_power_change_state(chip->card, SNDRV_CTL_POWER_D0);
 676         chip->autosuspended = 0;
 677
 678 err_out:
 679         return err;
 680 }
 681 #else
 682 #define usb_audio_suspend       NULL
 683 #define usb_audio_resume        NULL
 684 #endif          /* CONFIG_PM */
 685
 686 static struct usb_device_id usb_audio_ids [] = {
 687 #include "quirks-table.h"
 688     { .match_flags = (USB_DEVICE_ID_MATCH_INT_CLASS | USB_DEVICE_ID_MATCH_INT_SUBCLASS),
 689       .bInterfaceClass = USB_CLASS_AUDIO,
 690       .bInterfaceSubClass = USB_SUBCLASS_AUDIOCONTROL },
 691     { }                                         /* Terminating entry */
 692 };
 693
 694 MODULE_DEVICE_TABLE (usb, usb_audio_ids);
 695
 696 /*
 697  * entry point for linux usb interface
 698  */
 699
 700 static struct usb_driver usb_audio_driver = {
 701         .name =         "snd-usb-audio",
 702         .probe =        usb_audio_probe,
 703         .disconnect =   usb_audio_disconnect,
 704         .suspend =      usb_audio_suspend,
 705         .resume =       usb_audio_resume,
 706         .id_table =     usb_audio_ids,
 707         .supports_autosuspend = 1,
 708 };
 709
 710 static int __init snd_usb_audio_init(void)
 711 {
 712         if (nrpacks < 1 || nrpacks > MAX_PACKS) {
 713                 printk(KERN_WARNING "invalid nrpacks value.\n");
 714                 return -EINVAL;
 715         }
 716         return usb_register(&usb_audio_driver);
 717 }
 718
 719 static void __exit snd_usb_audio_cleanup(void)
 720 {
 721         usb_deregister(&usb_audio_driver);
 722 }
 723
 724 module_init(snd_usb_audio_init);
 725 module_exit(snd_usb_audio_cleanup);