kernel/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  *   - 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 device_setup[SNDRV_CARDS]; /* device parameter for this card */
  83 static bool ignore_ctl_error;
  84 static bool autoclock = true;
  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_array(device_setup, int, NULL, 0444);
  97 MODULE_PARM_DESC(device_setup, "Specific device setup (if needed).");
  98 module_param(ignore_ctl_error, bool, 0444);
  99 MODULE_PARM_DESC(ignore_ctl_error,
 100                  "Ignore errors from USB controller for mixer interfaces.");
 101 module_param(autoclock, bool, 0444);
 102 MODULE_PARM_DESC(autoclock, "Enable auto-clock selection for UAC2 devices (default: yes).");
 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 usb_audio_disconnect()
 116  */
 117 static void snd_usb_stream_disconnect(struct snd_usb_stream *as)
 118 {
 119         int idx;
 120         struct snd_usb_substream *subs;
 121
 122         for (idx = 0; idx < 2; idx++) {
 123                 subs = &as->substream[idx];
 124                 if (!subs->num_formats)
 125                         continue;
 126                 subs->interface = -1;
 127                 subs->data_endpoint = NULL;
 128                 subs->sync_endpoint = NULL;
 129         }
 130 }
 131
 132 static int snd_usb_create_stream(struct snd_usb_audio *chip, int ctrlif, int interface)
 133 {
 134         struct usb_device *dev = chip->dev;
 135         struct usb_host_interface *alts;
 136         struct usb_interface_descriptor *altsd;
 137         struct usb_interface *iface = usb_ifnum_to_if(dev, interface);
 138
 139         if (!iface) {
 140                 dev_err(&dev->dev, "%u:%d : does not exist\n",
 141                         ctrlif, interface);
 142                 return -EINVAL;
 143         }
 144
 145         alts = &iface->altsetting[0];
 146         altsd = get_iface_desc(alts);
 147
 148         /*
 149          * Android with both accessory and audio interfaces enabled gets the
 150          * interface numbers wrong.
 151          */
 152         if ((chip->usb_id == USB_ID(0x18d1, 0x2d04) ||
 153              chip->usb_id == USB_ID(0x18d1, 0x2d05)) &&
 154             interface == 0 &&
 155             altsd->bInterfaceClass == USB_CLASS_VENDOR_SPEC &&
 156             altsd->bInterfaceSubClass == USB_SUBCLASS_VENDOR_SPEC) {
 157                 interface = 2;
 158                 iface = usb_ifnum_to_if(dev, interface);
 159                 if (!iface)
 160                         return -EINVAL;
 161                 alts = &iface->altsetting[0];
 162                 altsd = get_iface_desc(alts);
 163         }
 164
 165         if (usb_interface_claimed(iface)) {
 166                 dev_dbg(&dev->dev, "%d:%d: skipping, already claimed\n",
 167                         ctrlif, interface);
 168                 return -EINVAL;
 169         }
 170
 171         if ((altsd->bInterfaceClass == USB_CLASS_AUDIO ||
 172              altsd->bInterfaceClass == USB_CLASS_VENDOR_SPEC) &&
 173             altsd->bInterfaceSubClass == USB_SUBCLASS_MIDISTREAMING) {
 174                 int err = snd_usbmidi_create(chip->card, iface,
 175                                              &chip->midi_list, NULL);
 176                 if (err < 0) {
 177                         dev_err(&dev->dev,
 178                                 "%u:%d: cannot create sequencer device\n",
 179                                 ctrlif, interface);
 180                         return -EINVAL;
 181                 }
 182                 usb_driver_claim_interface(&usb_audio_driver, iface, (void *)-1L);
 183
 184                 return 0;
 185         }
 186
 187         if ((altsd->bInterfaceClass != USB_CLASS_AUDIO &&
 188              altsd->bInterfaceClass != USB_CLASS_VENDOR_SPEC) ||
 189             altsd->bInterfaceSubClass != USB_SUBCLASS_AUDIOSTREAMING) {
 190                 dev_dbg(&dev->dev,
 191                         "%u:%d: skipping non-supported interface %d\n",
 192                         ctrlif, interface, altsd->bInterfaceClass);
 193                 /* skip non-supported classes */
 194                 return -EINVAL;
 195         }
 196
 197         if (snd_usb_get_speed(dev) == USB_SPEED_LOW) {
 198                 dev_err(&dev->dev, "low speed audio streaming not supported\n");
 199                 return -EINVAL;
 200         }
 201
 202         if (! snd_usb_parse_audio_interface(chip, interface)) {
 203                 usb_set_interface(dev, interface, 0); /* reset the current interface */
 204                 usb_driver_claim_interface(&usb_audio_driver, iface, (void *)-1L);
 205                 return -EINVAL;
 206         }
 207
 208         return 0;
 209 }
 210
 211 /*
 212  * parse audio control descriptor and create pcm/midi streams
 213  */
 214 static int snd_usb_create_streams(struct snd_usb_audio *chip, int ctrlif)
 215 {
 216         struct usb_device *dev = chip->dev;
 217         struct usb_host_interface *host_iface;
 218         struct usb_interface_descriptor *altsd;
 219         void *control_header;
 220         int i, protocol;
 221
 222         /* find audiocontrol interface */
 223         host_iface = &usb_ifnum_to_if(dev, ctrlif)->altsetting[0];
 224         control_header = snd_usb_find_csint_desc(host_iface->extra,
 225                                                  host_iface->extralen,
 226                                                  NULL, UAC_HEADER);
 227         altsd = get_iface_desc(host_iface);
 228         protocol = altsd->bInterfaceProtocol;
 229
 230         if (!control_header) {
 231                 dev_err(&dev->dev, "cannot find UAC_HEADER\n");
 232                 return -EINVAL;
 233         }
 234
 235         switch (protocol) {
 236         default:
 237                 dev_warn(&dev->dev,
 238                          "unknown interface protocol %#02x, assuming v1\n",
 239                          protocol);
 240                 /* fall through */
 241
 242         case UAC_VERSION_1: {
 243                 struct uac1_ac_header_descriptor *h1 = control_header;
 244
 245                 if (!h1->bInCollection) {
 246                         dev_info(&dev->dev, "skipping empty audio interface (v1)\n");
 247                         return -EINVAL;
 248                 }
 249
 250                 if (h1->bLength < sizeof(*h1) + h1->bInCollection) {
 251                         dev_err(&dev->dev, "invalid UAC_HEADER (v1)\n");
 252                         return -EINVAL;
 253                 }
 254
 255                 for (i = 0; i < h1->bInCollection; i++)
 256                         snd_usb_create_stream(chip, ctrlif, h1->baInterfaceNr[i]);
 257
 258                 break;
 259         }
 260
 261         case UAC_VERSION_2: {
 262                 struct usb_interface_assoc_descriptor *assoc =
 263                         usb_ifnum_to_if(dev, ctrlif)->intf_assoc;
 264
 265                 if (!assoc) {
 266                         /*
 267                          * Firmware writers cannot count to three.  So to find
 268                          * the IAD on the NuForce UDH-100, also check the next
 269                          * interface.
 270                          */
 271                         struct usb_interface *iface =
 272                                 usb_ifnum_to_if(dev, ctrlif + 1);
 273                         if (iface &&
 274                             iface->intf_assoc &&
 275                             iface->intf_assoc->bFunctionClass == USB_CLASS_AUDIO &&
 276                             iface->intf_assoc->bFunctionProtocol == UAC_VERSION_2)
 277                                 assoc = iface->intf_assoc;
 278                 }
 279
 280                 if (!assoc) {
 281                         dev_err(&dev->dev, "Audio class v2 interfaces need an interface association\n");
 282                         return -EINVAL;
 283                 }
 284
 285                 for (i = 0; i < assoc->bInterfaceCount; i++) {
 286                         int intf = assoc->bFirstInterface + i;
 287
 288                         if (intf != ctrlif)
 289                                 snd_usb_create_stream(chip, ctrlif, intf);
 290                 }
 291
 292                 break;
 293         }
 294         }
 295
 296         return 0;
 297 }
 298
 299 /*
 300  * free the chip instance
 301  *
 302  * here we have to do not much, since pcm and controls are already freed
 303  *
 304  */
 305
 306 static int snd_usb_audio_free(struct snd_usb_audio *chip)
 307 {
 308         struct snd_usb_endpoint *ep, *n;
 309
 310         list_for_each_entry_safe(ep, n, &chip->ep_list, list)
 311                 snd_usb_endpoint_free(ep);
 312
 313         mutex_destroy(&chip->mutex);
 314         kfree(chip);
 315         return 0;
 316 }
 317
 318 static int snd_usb_audio_dev_free(struct snd_device *device)
 319 {
 320         struct snd_usb_audio *chip = device->device_data;
 321         return snd_usb_audio_free(chip);
 322 }
 323
 324 /*
 325  * create a chip instance and set its names.
 326  */
 327 static int snd_usb_audio_create(struct usb_interface *intf,
 328                                 struct usb_device *dev, int idx,
 329                                 const struct snd_usb_audio_quirk *quirk,
 330                                 struct snd_usb_audio **rchip)
 331 {
 332         struct snd_card *card;
 333         struct snd_usb_audio *chip;
 334         int err, len;
 335         char component[14];
 336         static struct snd_device_ops ops = {
 337                 .dev_free =     snd_usb_audio_dev_free,
 338         };
 339
 340         *rchip = NULL;
 341
 342         switch (snd_usb_get_speed(dev)) {
 343         case USB_SPEED_LOW:
 344         case USB_SPEED_FULL:
 345         case USB_SPEED_HIGH:
 346         case USB_SPEED_WIRELESS:
 347         case USB_SPEED_SUPER:
 348                 break;
 349         default:
 350                 dev_err(&dev->dev, "unknown device speed %d\n", snd_usb_get_speed(dev));
 351                 return -ENXIO;
 352         }
 353
 354         err = snd_card_new(&intf->dev, index[idx], id[idx], THIS_MODULE,
 355                            0, &card);
 356         if (err < 0) {
 357                 dev_err(&dev->dev, "cannot create card instance %d\n", idx);
 358                 return err;
 359         }
 360
 361         chip = kzalloc(sizeof(*chip), GFP_KERNEL);
 362         if (! chip) {
 363                 snd_card_free(card);
 364                 return -ENOMEM;
 365         }
 366
 367         mutex_init(&chip->mutex);
 368         init_rwsem(&chip->shutdown_rwsem);
 369         chip->index = idx;
 370         chip->dev = dev;
 371         chip->card = card;
 372         chip->setup = device_setup[idx];
 373         chip->autoclock = autoclock;
 374         chip->probing = 1;
 375
 376         chip->usb_id = USB_ID(le16_to_cpu(dev->descriptor.idVendor),
 377                               le16_to_cpu(dev->descriptor.idProduct));
 378         INIT_LIST_HEAD(&chip->pcm_list);
 379         INIT_LIST_HEAD(&chip->ep_list);
 380         INIT_LIST_HEAD(&chip->midi_list);
 381         INIT_LIST_HEAD(&chip->mixer_list);
 382
 383         if ((err = snd_device_new(card, SNDRV_DEV_LOWLEVEL, chip, &ops)) < 0) {
 384                 snd_usb_audio_free(chip);
 385                 snd_card_free(card);
 386                 return err;
 387         }
 388
 389         strcpy(card->driver, "USB-Audio");
 390         sprintf(component, "USB%04x:%04x",
 391                 USB_ID_VENDOR(chip->usb_id), USB_ID_PRODUCT(chip->usb_id));
 392         snd_component_add(card, component);
 393
 394         /* retrieve the device string as shortname */
 395         if (quirk && quirk->product_name && *quirk->product_name) {
 396                 strlcpy(card->shortname, quirk->product_name, sizeof(card->shortname));
 397         } else {
 398                 if (!dev->descriptor.iProduct ||
 399                     usb_string(dev, dev->descriptor.iProduct,
 400                     card->shortname, sizeof(card->shortname)) <= 0) {
 401                         /* no name available from anywhere, so use ID */
 402                         sprintf(card->shortname, "USB Device %#04x:%#04x",
 403                                 USB_ID_VENDOR(chip->usb_id),
 404                                 USB_ID_PRODUCT(chip->usb_id));
 405                 }
 406         }
 407         strim(card->shortname);
 408
 409         /* retrieve the vendor and device strings as longname */
 410         if (quirk && quirk->vendor_name && *quirk->vendor_name) {
 411                 len = strlcpy(card->longname, quirk->vendor_name, sizeof(card->longname));
 412         } else {
 413                 if (dev->descriptor.iManufacturer)
 414                         len = usb_string(dev, dev->descriptor.iManufacturer,
 415                                          card->longname, sizeof(card->longname));
 416                 else
 417                         len = 0;
 418                 /* we don't really care if there isn't any vendor string */
 419         }
 420         if (len > 0) {
 421                 strim(card->longname);
 422                 if (*card->longname)
 423                         strlcat(card->longname, " ", sizeof(card->longname));
 424         }
 425
 426         strlcat(card->longname, card->shortname, sizeof(card->longname));
 427
 428         len = strlcat(card->longname, " at ", sizeof(card->longname));
 429
 430         if (len < sizeof(card->longname))
 431                 usb_make_path(dev, card->longname + len, sizeof(card->longname) - len);
 432
 433         switch (snd_usb_get_speed(dev)) {
 434         case USB_SPEED_LOW:
 435                 strlcat(card->longname, ", low speed", sizeof(card->longname));
 436                 break;
 437         case USB_SPEED_FULL:
 438                 strlcat(card->longname, ", full speed", sizeof(card->longname));
 439                 break;
 440         case USB_SPEED_HIGH:
 441                 strlcat(card->longname, ", high speed", sizeof(card->longname));
 442                 break;
 443         case USB_SPEED_SUPER:
 444                 strlcat(card->longname, ", super speed", sizeof(card->longname));
 445                 break;
 446         default:
 447                 break;
 448         }
 449
 450         snd_usb_audio_create_proc(chip);
 451
 452         *rchip = chip;
 453         return 0;
 454 }
 455
 456 /*
 457  * probe the active usb device
 458  *
 459  * note that this can be called multiple times per a device, when it
 460  * includes multiple audio control interfaces.
 461  *
 462  * thus we check the usb device pointer and creates the card instance
 463  * only at the first time.  the successive calls of this function will
 464  * append the pcm interface to the corresponding card.
 465  */
 466 static int usb_audio_probe(struct usb_interface *intf,
 467                            const struct usb_device_id *usb_id)
 468 {
 469         struct usb_device *dev = interface_to_usbdev(intf);
 470         const struct snd_usb_audio_quirk *quirk =
 471                 (const struct snd_usb_audio_quirk *)usb_id->driver_info;
 472         struct snd_usb_audio *chip;
 473         int i, err;
 474         struct usb_host_interface *alts;
 475         int ifnum;
 476         u32 id;
 477
 478         alts = &intf->altsetting[0];
 479         ifnum = get_iface_desc(alts)->bInterfaceNumber;
 480         id = USB_ID(le16_to_cpu(dev->descriptor.idVendor),
 481                     le16_to_cpu(dev->descriptor.idProduct));
 482         if (quirk && quirk->ifnum >= 0 && ifnum != quirk->ifnum)
 483                 return -ENXIO;
 484
 485         err = snd_usb_apply_boot_quirk(dev, intf, quirk);
 486         if (err < 0)
 487                 return err;
 488
 489         /*
 490          * found a config.  now register to ALSA
 491          */
 492
 493         /* check whether it's already registered */
 494         chip = NULL;
 495         mutex_lock(&register_mutex);
 496         for (i = 0; i < SNDRV_CARDS; i++) {
 497                 if (usb_chip[i] && usb_chip[i]->dev == dev) {
 498                         if (usb_chip[i]->shutdown) {
 499                                 dev_err(&dev->dev, "USB device is in the shutdown state, cannot create a card instance\n");
 500                                 err = -EIO;
 501                                 goto __error;
 502                         }
 503                         chip = usb_chip[i];
 504                         chip->probing = 1;
 505                         break;
 506                 }
 507         }
 508         if (! chip) {
 509                 /* it's a fresh one.
 510                  * now look for an empty slot and create a new card instance
 511                  */
 512                 for (i = 0; i < SNDRV_CARDS; i++)
 513                         if (enable[i] && ! usb_chip[i] &&
 514                             (vid[i] == -1 || vid[i] == USB_ID_VENDOR(id)) &&
 515                             (pid[i] == -1 || pid[i] == USB_ID_PRODUCT(id))) {
 516                                 err = snd_usb_audio_create(intf, dev, i, quirk,
 517                                                            &chip);
 518                                 if (err < 0)
 519                                         goto __error;
 520                                 chip->pm_intf = intf;
 521                                 break;
 522                         }
 523                 if (!chip) {
 524                         dev_err(&dev->dev, "no available usb audio device\n");
 525                         err = -ENODEV;
 526                         goto __error;
 527                 }
 528         }
 529
 530         /*
 531          * For devices with more than one control interface, we assume the
 532          * first contains the audio controls. We might need a more specific
 533          * check here in the future.
 534          */
 535         if (!chip->ctrl_intf)
 536                 chip->ctrl_intf = alts;
 537
 538         chip->txfr_quirk = 0;
 539         err = 1; /* continue */
 540         if (quirk && quirk->ifnum != QUIRK_NO_INTERFACE) {
 541                 /* need some special handlings */
 542                 err = snd_usb_create_quirk(chip, intf, &usb_audio_driver, quirk);
 543                 if (err < 0)
 544                         goto __error;
 545         }
 546
 547         if (err > 0) {
 548                 /* create normal USB audio interfaces */
 549                 err = snd_usb_create_streams(chip, ifnum);
 550                 if (err < 0)
 551                         goto __error;
 552                 err = snd_usb_create_mixer(chip, ifnum, ignore_ctl_error);
 553                 if (err < 0)
 554                         goto __error;
 555         }
 556
 557         /* we are allowed to call snd_card_register() many times */
 558         err = snd_card_register(chip->card);
 559         if (err < 0)
 560                 goto __error;
 561
 562         usb_chip[chip->index] = chip;
 563         chip->num_interfaces++;
 564         chip->probing = 0;
 565         usb_set_intfdata(intf, chip);
 566         mutex_unlock(&register_mutex);
 567         return 0;
 568
 569  __error:
 570         if (chip) {
 571                 if (!chip->num_interfaces)
 572                         snd_card_free(chip->card);
 573                 chip->probing = 0;
 574         }
 575         mutex_unlock(&register_mutex);
 576         return err;
 577 }
 578
 579 /*
 580  * we need to take care of counter, since disconnection can be called also
 581  * many times as well as usb_audio_probe().
 582  */
 583 static void usb_audio_disconnect(struct usb_interface *intf)
 584 {
 585         struct snd_usb_audio *chip = usb_get_intfdata(intf);
 586         struct snd_card *card;
 587         struct list_head *p;
 588         bool was_shutdown;
 589
 590         if (chip == (void *)-1L)
 591                 return;
 592
 593         card = chip->card;
 594         down_write(&chip->shutdown_rwsem);
 595         was_shutdown = chip->shutdown;
 596         chip->shutdown = 1;
 597         up_write(&chip->shutdown_rwsem);
 598
 599         mutex_lock(&register_mutex);
 600         if (!was_shutdown) {
 601                 struct snd_usb_stream *as;
 602                 struct snd_usb_endpoint *ep;
 603                 struct usb_mixer_interface *mixer;
 604
 605                 snd_card_disconnect(card);
 606                 /* release the pcm resources */
 607                 list_for_each_entry(as, &chip->pcm_list, list) {
 608                         snd_usb_stream_disconnect(as);
 609                 }
 610                 /* release the endpoint resources */
 611                 list_for_each_entry(ep, &chip->ep_list, list) {
 612                         snd_usb_endpoint_release(ep);
 613                 }
 614                 /* release the midi resources */
 615                 list_for_each(p, &chip->midi_list) {
 616                         snd_usbmidi_disconnect(p);
 617                 }
 618                 /* release mixer resources */
 619                 list_for_each_entry(mixer, &chip->mixer_list, list) {
 620                         snd_usb_mixer_disconnect(mixer);
 621                 }
 622         }
 623
 624         chip->num_interfaces--;
 625         if (chip->num_interfaces <= 0) {
 626                 usb_chip[chip->index] = NULL;
 627                 mutex_unlock(&register_mutex);
 628                 snd_card_free_when_closed(card);
 629         } else {
 630                 mutex_unlock(&register_mutex);
 631         }
 632 }
 633
 634 #ifdef CONFIG_PM
 635
 636 int snd_usb_autoresume(struct snd_usb_audio *chip)
 637 {
 638         int err = -ENODEV;
 639
 640         down_read(&chip->shutdown_rwsem);
 641         if (chip->probing || chip->in_pm)
 642                 err = 0;
 643         else if (!chip->shutdown)
 644                 err = usb_autopm_get_interface(chip->pm_intf);
 645         up_read(&chip->shutdown_rwsem);
 646
 647         return err;
 648 }
 649
 650 void snd_usb_autosuspend(struct snd_usb_audio *chip)
 651 {
 652         down_read(&chip->shutdown_rwsem);
 653         if (!chip->shutdown && !chip->probing && !chip->in_pm)
 654                 usb_autopm_put_interface(chip->pm_intf);
 655         up_read(&chip->shutdown_rwsem);
 656 }
 657
 658 static int usb_audio_suspend(struct usb_interface *intf, pm_message_t message)
 659 {
 660         struct snd_usb_audio *chip = usb_get_intfdata(intf);
 661         struct snd_usb_stream *as;
 662         struct usb_mixer_interface *mixer;
 663         struct list_head *p;
 664
 665         if (chip == (void *)-1L)
 666                 return 0;
 667
 668         if (!PMSG_IS_AUTO(message)) {
 669                 snd_power_change_state(chip->card, SNDRV_CTL_POWER_D3hot);
 670                 if (!chip->num_suspended_intf++) {
 671                         list_for_each_entry(as, &chip->pcm_list, list) {
 672                                 snd_pcm_suspend_all(as->pcm);
 673                                 as->substream[0].need_setup_ep =
 674                                         as->substream[1].need_setup_ep = true;
 675                         }
 676                         list_for_each(p, &chip->midi_list) {
 677                                 snd_usbmidi_suspend(p);
 678                         }
 679                 }
 680         } else {
 681                 /*
 682                  * otherwise we keep the rest of the system in the dark
 683                  * to keep this transparent
 684                  */
 685                 if (!chip->num_suspended_intf++)
 686                         chip->autosuspended = 1;
 687         }
 688
 689         if (chip->num_suspended_intf == 1)
 690                 list_for_each_entry(mixer, &chip->mixer_list, list)
 691                         snd_usb_mixer_suspend(mixer);
 692
 693         return 0;
 694 }
 695
 696 static int __usb_audio_resume(struct usb_interface *intf, bool reset_resume)
 697 {
 698         struct snd_usb_audio *chip = usb_get_intfdata(intf);
 699         struct usb_mixer_interface *mixer;
 700         struct list_head *p;
 701         int err = 0;
 702
 703         if (chip == (void *)-1L)
 704                 return 0;
 705         if (--chip->num_suspended_intf)
 706                 return 0;
 707
 708         chip->in_pm = 1;
 709         /*
 710          * ALSA leaves material resumption to user space
 711          * we just notify and restart the mixers
 712          */
 713         list_for_each_entry(mixer, &chip->mixer_list, list) {
 714                 err = snd_usb_mixer_resume(mixer, reset_resume);
 715                 if (err < 0)
 716                         goto err_out;
 717         }
 718
 719         list_for_each(p, &chip->midi_list) {
 720                 snd_usbmidi_resume(p);
 721         }
 722
 723         if (!chip->autosuspended)
 724                 snd_power_change_state(chip->card, SNDRV_CTL_POWER_D0);
 725         chip->autosuspended = 0;
 726
 727 err_out:
 728         chip->in_pm = 0;
 729         return err;
 730 }
 731
 732 static int usb_audio_resume(struct usb_interface *intf)
 733 {
 734         return __usb_audio_resume(intf, false);
 735 }
 736
 737 static int usb_audio_reset_resume(struct usb_interface *intf)
 738 {
 739         return __usb_audio_resume(intf, true);
 740 }
 741 #else
 742 #define usb_audio_suspend       NULL
 743 #define usb_audio_resume        NULL
 744 #define usb_audio_reset_resume  NULL
 745 #endif          /* CONFIG_PM */
 746
 747 static struct usb_device_id usb_audio_ids [] = {
 748 #include "quirks-table.h"
 749     { .match_flags = (USB_DEVICE_ID_MATCH_INT_CLASS | USB_DEVICE_ID_MATCH_INT_SUBCLASS),
 750       .bInterfaceClass = USB_CLASS_AUDIO,
 751       .bInterfaceSubClass = USB_SUBCLASS_AUDIOCONTROL },
 752     { }                                         /* Terminating entry */
 753 };
 754 MODULE_DEVICE_TABLE(usb, usb_audio_ids);
 755
 756 /*
 757  * entry point for linux usb interface
 758  */
 759
 760 static struct usb_driver usb_audio_driver = {
 761         .name =         "snd-usb-audio",
 762         .probe =        usb_audio_probe,
 763         .disconnect =   usb_audio_disconnect,
 764         .suspend =      usb_audio_suspend,
 765         .resume =       usb_audio_resume,
 766         .reset_resume = usb_audio_reset_resume,
 767         .id_table =     usb_audio_ids,
 768         .supports_autosuspend = 1,
 769 };
 770
 771 module_usb_driver(usb_audio_driver);