sound/usb/card.c

   1 // SPDX-License-Identifier: GPL-2.0-or-later
   2 /*
   3  *   (Tentative) USB Audio Driver for ALSA
   4  *
   5  *   Copyright (c) 2002 by Takashi Iwai <[email protected]>
   6  *
   7  *   Many codes borrowed from audio.c by
   8  *          Alan Cox ([email protected])
   9  *          Thomas Sailer ([email protected])
  10  *
  11  *   Audio Class 3.0 support by Ruslan Bilovol <[email protected]>
  12  *
  13  *  NOTES:
  14  *
  15  *   - the linked URBs would be preferred but not used so far because of
  16  *     the instability of unlinking.
  17  *   - type II is not supported properly.  there is no device which supports
  18  *     this type *correctly*.  SB extigy looks as if it supports, but it's
  19  *     indeed an AC3 stream packed in SPDIF frames (i.e. no real AC3 stream).
  20  */
  21
  22
  23 #include <linux/bitops.h>
  24 #include <linux/init.h>
  25 #include <linux/list.h>
  26 #include <linux/slab.h>
  27 #include <linux/string.h>
  28 #include <linux/ctype.h>
  29 #include <linux/usb.h>
  30 #include <linux/moduleparam.h>
  31 #include <linux/mutex.h>
  32 #include <linux/usb/audio.h>
  33 #include <linux/usb/audio-v2.h>
  34 #include <linux/usb/audio-v3.h>
  35 #include <linux/module.h>
  36
  37 #include <sound/control.h>
  38 #include <sound/core.h>
  39 #include <sound/info.h>
  40 #include <sound/pcm.h>
  41 #include <sound/pcm_params.h>
  42 #include <sound/initval.h>
  43
  44 #include "usbaudio.h"
  45 #include "card.h"
  46 #include "midi.h"
  47 #include "mixer.h"
  48 #include "proc.h"
  49 #include "quirks.h"
  50 #include "endpoint.h"
  51 #include "helper.h"
  52 #include "debug.h"
  53 #include "pcm.h"
  54 #include "format.h"
  55 #include "power.h"
  56 #include "stream.h"
  57 #include "media.h"
  58
  59 MODULE_AUTHOR("Takashi Iwai <[email protected]>");
  60 MODULE_DESCRIPTION("USB Audio");
  61 MODULE_LICENSE("GPL");
  62 MODULE_SUPPORTED_DEVICE("{{Generic,USB Audio}}");
  63
  64
  65 static int index[SNDRV_CARDS] = SNDRV_DEFAULT_IDX;      /* Index 0-MAX */
  66 static char *id[SNDRV_CARDS] = SNDRV_DEFAULT_STR;       /* ID for this card */
  67 static bool enable[SNDRV_CARDS] = SNDRV_DEFAULT_ENABLE_PNP;/* Enable this card */
  68 /* Vendor/product IDs for this card */
  69 static int vid[SNDRV_CARDS] = { [0 ... (SNDRV_CARDS-1)] = -1 };
  70 static int pid[SNDRV_CARDS] = { [0 ... (SNDRV_CARDS-1)] = -1 };
  71 static int device_setup[SNDRV_CARDS]; /* device parameter for this card */
  72 static bool ignore_ctl_error;
  73 static bool autoclock = true;
  74 static char *quirk_alias[SNDRV_CARDS];
  75
  76 bool snd_usb_use_vmalloc = true;
  77 bool snd_usb_skip_validation;
  78
  79 module_param_array(index, int, NULL, 0444);
  80 MODULE_PARM_DESC(index, "Index value for the USB audio adapter.");
  81 module_param_array(id, charp, NULL, 0444);
  82 MODULE_PARM_DESC(id, "ID string for the USB audio adapter.");
  83 module_param_array(enable, bool, NULL, 0444);
  84 MODULE_PARM_DESC(enable, "Enable USB audio adapter.");
  85 module_param_array(vid, int, NULL, 0444);
  86 MODULE_PARM_DESC(vid, "Vendor ID for the USB audio device.");
  87 module_param_array(pid, int, NULL, 0444);
  88 MODULE_PARM_DESC(pid, "Product ID for the USB audio device.");
  89 module_param_array(device_setup, int, NULL, 0444);
  90 MODULE_PARM_DESC(device_setup, "Specific device setup (if needed).");
  91 module_param(ignore_ctl_error, bool, 0444);
  92 MODULE_PARM_DESC(ignore_ctl_error,
  93                  "Ignore errors from USB controller for mixer interfaces.");
  94 module_param(autoclock, bool, 0444);
  95 MODULE_PARM_DESC(autoclock, "Enable auto-clock selection for UAC2 devices (default: yes).");
  96 module_param_array(quirk_alias, charp, NULL, 0444);
  97 MODULE_PARM_DESC(quirk_alias, "Quirk aliases, e.g. 0123abcd:5678beef.");
  98 module_param_named(use_vmalloc, snd_usb_use_vmalloc, bool, 0444);
  99 MODULE_PARM_DESC(use_vmalloc, "Use vmalloc for PCM intermediate buffers (default: yes).");
 100 module_param_named(skip_validation, snd_usb_skip_validation, bool, 0444);
 101 MODULE_PARM_DESC(skip_validation, "Skip unit descriptor validation (default: no).");
 102
 103 /*
 104  * we keep the snd_usb_audio_t instances by ourselves for merging
 105  * the all interfaces on the same card as one sound device.
 106  */
 107
 108 static DEFINE_MUTEX(register_mutex);
 109 static struct snd_usb_audio *usb_chip[SNDRV_CARDS];
 110 static struct usb_driver usb_audio_driver;
 111
 112 /*
 113  * disconnect streams
 114  * called from usb_audio_disconnect()
 115  */
 116 static void snd_usb_stream_disconnect(struct snd_usb_stream *as)
 117 {
 118         int idx;
 119         struct snd_usb_substream *subs;
 120
 121         for (idx = 0; idx < 2; idx++) {
 122                 subs = &as->substream[idx];
 123                 if (!subs->num_formats)
 124                         continue;
 125                 subs->interface = -1;
 126                 subs->data_endpoint = NULL;
 127                 subs->sync_endpoint = NULL;
 128         }
 129 }
 130
 131 static int snd_usb_create_stream(struct snd_usb_audio *chip, int ctrlif, int interface)
 132 {
 133         struct usb_device *dev = chip->dev;
 134         struct usb_host_interface *alts;
 135         struct usb_interface_descriptor *altsd;
 136         struct usb_interface *iface = usb_ifnum_to_if(dev, interface);
 137
 138         if (!iface) {
 139                 dev_err(&dev->dev, "%u:%d : does not exist\n",
 140                         ctrlif, interface);
 141                 return -EINVAL;
 142         }
 143
 144         alts = &iface->altsetting[0];
 145         altsd = get_iface_desc(alts);
 146
 147         /*
 148          * Android with both accessory and audio interfaces enabled gets the
 149          * interface numbers wrong.
 150          */
 151         if ((chip->usb_id == USB_ID(0x18d1, 0x2d04) ||
 152              chip->usb_id == USB_ID(0x18d1, 0x2d05)) &&
 153             interface == 0 &&
 154             altsd->bInterfaceClass == USB_CLASS_VENDOR_SPEC &&
 155             altsd->bInterfaceSubClass == USB_SUBCLASS_VENDOR_SPEC) {
 156                 interface = 2;
 157                 iface = usb_ifnum_to_if(dev, interface);
 158                 if (!iface)
 159                         return -EINVAL;
 160                 alts = &iface->altsetting[0];
 161                 altsd = get_iface_desc(alts);
 162         }
 163
 164         if (usb_interface_claimed(iface)) {
 165                 dev_dbg(&dev->dev, "%d:%d: skipping, already claimed\n",
 166                         ctrlif, interface);
 167                 return -EINVAL;
 168         }
 169
 170         if ((altsd->bInterfaceClass == USB_CLASS_AUDIO ||
 171              altsd->bInterfaceClass == USB_CLASS_VENDOR_SPEC) &&
 172             altsd->bInterfaceSubClass == USB_SUBCLASS_MIDISTREAMING) {
 173                 int err = __snd_usbmidi_create(chip->card, iface,
 174                                              &chip->midi_list, NULL,
 175                                              chip->usb_id);
 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         }
 206
 207         return 0;
 208 }
 209
 210 /*
 211  * parse audio control descriptor and create pcm/midi streams
 212  */
 213 static int snd_usb_create_streams(struct snd_usb_audio *chip, int ctrlif)
 214 {
 215         struct usb_device *dev = chip->dev;
 216         struct usb_host_interface *host_iface;
 217         struct usb_interface_descriptor *altsd;
 218         int i, protocol;
 219
 220         /* find audiocontrol interface */
 221         host_iface = &usb_ifnum_to_if(dev, ctrlif)->altsetting[0];
 222         altsd = get_iface_desc(host_iface);
 223         protocol = altsd->bInterfaceProtocol;
 224
 225         switch (protocol) {
 226         default:
 227                 dev_warn(&dev->dev,
 228                          "unknown interface protocol %#02x, assuming v1\n",
 229                          protocol);
 230                 /* fall through */
 231
 232         case UAC_VERSION_1: {
 233                 struct uac1_ac_header_descriptor *h1;
 234                 int rest_bytes;
 235
 236                 h1 = snd_usb_find_csint_desc(host_iface->extra,
 237                                                          host_iface->extralen,
 238                                                          NULL, UAC_HEADER);
 239                 if (!h1 || h1->bLength < sizeof(*h1)) {
 240                         dev_err(&dev->dev, "cannot find UAC_HEADER\n");
 241                         return -EINVAL;
 242                 }
 243
 244                 rest_bytes = (void *)(host_iface->extra +
 245                                 host_iface->extralen) - (void *)h1;
 246
 247                 /* just to be sure -- this shouldn't hit at all */
 248                 if (rest_bytes <= 0) {
 249                         dev_err(&dev->dev, "invalid control header\n");
 250                         return -EINVAL;
 251                 }
 252
 253                 if (rest_bytes < sizeof(*h1)) {
 254                         dev_err(&dev->dev, "too short v1 buffer descriptor\n");
 255                         return -EINVAL;
 256                 }
 257
 258                 if (!h1->bInCollection) {
 259                         dev_info(&dev->dev, "skipping empty audio interface (v1)\n");
 260                         return -EINVAL;
 261                 }
 262
 263                 if (rest_bytes < h1->bLength) {
 264                         dev_err(&dev->dev, "invalid buffer length (v1)\n");
 265                         return -EINVAL;
 266                 }
 267
 268                 if (h1->bLength < sizeof(*h1) + h1->bInCollection) {
 269                         dev_err(&dev->dev, "invalid UAC_HEADER (v1)\n");
 270                         return -EINVAL;
 271                 }
 272
 273                 for (i = 0; i < h1->bInCollection; i++)
 274                         snd_usb_create_stream(chip, ctrlif, h1->baInterfaceNr[i]);
 275
 276                 break;
 277         }
 278
 279         case UAC_VERSION_2:
 280         case UAC_VERSION_3: {
 281                 struct usb_interface_assoc_descriptor *assoc =
 282                         usb_ifnum_to_if(dev, ctrlif)->intf_assoc;
 283
 284                 if (!assoc) {
 285                         /*
 286                          * Firmware writers cannot count to three.  So to find
 287                          * the IAD on the NuForce UDH-100, also check the next
 288                          * interface.
 289                          */
 290                         struct usb_interface *iface =
 291                                 usb_ifnum_to_if(dev, ctrlif + 1);
 292                         if (iface &&
 293                             iface->intf_assoc &&
 294                             iface->intf_assoc->bFunctionClass == USB_CLASS_AUDIO &&
 295                             iface->intf_assoc->bFunctionProtocol == UAC_VERSION_2)
 296                                 assoc = iface->intf_assoc;
 297                 }
 298
 299                 if (!assoc) {
 300                         dev_err(&dev->dev, "Audio class v2/v3 interfaces need an interface association\n");
 301                         return -EINVAL;
 302                 }
 303
 304                 if (protocol == UAC_VERSION_3) {
 305                         int badd = assoc->bFunctionSubClass;
 306
 307                         if (badd != UAC3_FUNCTION_SUBCLASS_FULL_ADC_3_0 &&
 308                             (badd < UAC3_FUNCTION_SUBCLASS_GENERIC_IO ||
 309                              badd > UAC3_FUNCTION_SUBCLASS_SPEAKERPHONE)) {
 310                                 dev_err(&dev->dev,
 311                                         "Unsupported UAC3 BADD profile\n");
 312                                 return -EINVAL;
 313                         }
 314
 315                         chip->badd_profile = badd;
 316                 }
 317
 318                 for (i = 0; i < assoc->bInterfaceCount; i++) {
 319                         int intf = assoc->bFirstInterface + i;
 320
 321                         if (intf != ctrlif)
 322                                 snd_usb_create_stream(chip, ctrlif, intf);
 323                 }
 324
 325                 break;
 326         }
 327         }
 328
 329         return 0;
 330 }
 331
 332 /*
 333  * free the chip instance
 334  *
 335  * here we have to do not much, since pcm and controls are already freed
 336  *
 337  */
 338
 339 static void snd_usb_audio_free(struct snd_card *card)
 340 {
 341         struct snd_usb_audio *chip = card->private_data;
 342         struct snd_usb_endpoint *ep, *n;
 343
 344         list_for_each_entry_safe(ep, n, &chip->ep_list, list)
 345                 snd_usb_endpoint_free(ep);
 346
 347         mutex_destroy(&chip->mutex);
 348         if (!atomic_read(&chip->shutdown))
 349                 dev_set_drvdata(&chip->dev->dev, NULL);
 350 }
 351
 352 static void usb_audio_make_shortname(struct usb_device *dev,
 353                                      struct snd_usb_audio *chip,
 354                                      const struct snd_usb_audio_quirk *quirk)
 355 {
 356         struct snd_card *card = chip->card;
 357
 358         if (quirk && quirk->product_name && *quirk->product_name) {
 359                 strlcpy(card->shortname, quirk->product_name,
 360                         sizeof(card->shortname));
 361                 return;
 362         }
 363
 364         /* retrieve the device string as shortname */
 365         if (!dev->descriptor.iProduct ||
 366             usb_string(dev, dev->descriptor.iProduct,
 367                        card->shortname, sizeof(card->shortname)) <= 0) {
 368                 /* no name available from anywhere, so use ID */
 369                 sprintf(card->shortname, "USB Device %#04x:%#04x",
 370                         USB_ID_VENDOR(chip->usb_id),
 371                         USB_ID_PRODUCT(chip->usb_id));
 372         }
 373
 374         strim(card->shortname);
 375 }
 376
 377 static void usb_audio_make_longname(struct usb_device *dev,
 378                                     struct snd_usb_audio *chip,
 379                                     const struct snd_usb_audio_quirk *quirk)
 380 {
 381         struct snd_card *card = chip->card;
 382         int len;
 383
 384         /* shortcut - if any pre-defined string is given, use it */
 385         if (quirk && quirk->profile_name && *quirk->profile_name) {
 386                 strlcpy(card->longname, quirk->profile_name,
 387                         sizeof(card->longname));
 388                 return;
 389         }
 390
 391         if (quirk && quirk->vendor_name && *quirk->vendor_name) {
 392                 len = strlcpy(card->longname, quirk->vendor_name, sizeof(card->longname));
 393         } else {
 394                 /* retrieve the vendor and device strings as longname */
 395                 if (dev->descriptor.iManufacturer)
 396                         len = usb_string(dev, dev->descriptor.iManufacturer,
 397                                          card->longname, sizeof(card->longname));
 398                 else
 399                         len = 0;
 400                 /* we don't really care if there isn't any vendor string */
 401         }
 402         if (len > 0) {
 403                 strim(card->longname);
 404                 if (*card->longname)
 405                         strlcat(card->longname, " ", sizeof(card->longname));
 406         }
 407
 408         strlcat(card->longname, card->shortname, sizeof(card->longname));
 409
 410         len = strlcat(card->longname, " at ", sizeof(card->longname));
 411
 412         if (len < sizeof(card->longname))
 413                 usb_make_path(dev, card->longname + len, sizeof(card->longname) - len);
 414
 415         switch (snd_usb_get_speed(dev)) {
 416         case USB_SPEED_LOW:
 417                 strlcat(card->longname, ", low speed", sizeof(card->longname));
 418                 break;
 419         case USB_SPEED_FULL:
 420                 strlcat(card->longname, ", full speed", sizeof(card->longname));
 421                 break;
 422         case USB_SPEED_HIGH:
 423                 strlcat(card->longname, ", high speed", sizeof(card->longname));
 424                 break;
 425         case USB_SPEED_SUPER:
 426                 strlcat(card->longname, ", super speed", sizeof(card->longname));
 427                 break;
 428         case USB_SPEED_SUPER_PLUS:
 429                 strlcat(card->longname, ", super speed plus", sizeof(card->longname));
 430                 break;
 431         default:
 432                 break;
 433         }
 434 }
 435
 436 /*
 437  * create a chip instance and set its names.
 438  */
 439 static int snd_usb_audio_create(struct usb_interface *intf,
 440                                 struct usb_device *dev, int idx,
 441                                 const struct snd_usb_audio_quirk *quirk,
 442                                 unsigned int usb_id,
 443                                 struct snd_usb_audio **rchip)
 444 {
 445         struct snd_card *card;
 446         struct snd_usb_audio *chip;
 447         int err;
 448         char component[14];
 449
 450         *rchip = NULL;
 451
 452         switch (snd_usb_get_speed(dev)) {
 453         case USB_SPEED_LOW:
 454         case USB_SPEED_FULL:
 455         case USB_SPEED_HIGH:
 456         case USB_SPEED_WIRELESS:
 457         case USB_SPEED_SUPER:
 458         case USB_SPEED_SUPER_PLUS:
 459                 break;
 460         default:
 461                 dev_err(&dev->dev, "unknown device speed %d\n", snd_usb_get_speed(dev));
 462                 return -ENXIO;
 463         }
 464
 465         err = snd_card_new(&intf->dev, index[idx], id[idx], THIS_MODULE,
 466                            sizeof(*chip), &card);
 467         if (err < 0) {
 468                 dev_err(&dev->dev, "cannot create card instance %d\n", idx);
 469                 return err;
 470         }
 471
 472         chip = card->private_data;
 473         mutex_init(&chip->mutex);
 474         init_waitqueue_head(&chip->shutdown_wait);
 475         chip->index = idx;
 476         chip->dev = dev;
 477         chip->card = card;
 478         chip->setup = device_setup[idx];
 479         chip->autoclock = autoclock;
 480         atomic_set(&chip->active, 1); /* avoid autopm during probing */
 481         atomic_set(&chip->usage_count, 0);
 482         atomic_set(&chip->shutdown, 0);
 483
 484         chip->usb_id = usb_id;
 485         INIT_LIST_HEAD(&chip->pcm_list);
 486         INIT_LIST_HEAD(&chip->ep_list);
 487         INIT_LIST_HEAD(&chip->midi_list);
 488         INIT_LIST_HEAD(&chip->mixer_list);
 489
 490         card->private_free = snd_usb_audio_free;
 491
 492         strcpy(card->driver, "USB-Audio");
 493         sprintf(component, "USB%04x:%04x",
 494                 USB_ID_VENDOR(chip->usb_id), USB_ID_PRODUCT(chip->usb_id));
 495         snd_component_add(card, component);
 496
 497         usb_audio_make_shortname(dev, chip, quirk);
 498         usb_audio_make_longname(dev, chip, quirk);
 499
 500         snd_usb_audio_create_proc(chip);
 501
 502         *rchip = chip;
 503         return 0;
 504 }
 505
 506 /* look for a matching quirk alias id */
 507 static bool get_alias_id(struct usb_device *dev, unsigned int *id)
 508 {
 509         int i;
 510         unsigned int src, dst;
 511
 512         for (i = 0; i < ARRAY_SIZE(quirk_alias); i++) {
 513                 if (!quirk_alias[i] ||
 514                     sscanf(quirk_alias[i], "%x:%x", &src, &dst) != 2 ||
 515                     src != *id)
 516                         continue;
 517                 dev_info(&dev->dev,
 518                          "device (%04x:%04x): applying quirk alias %04x:%04x\n",
 519                          USB_ID_VENDOR(*id), USB_ID_PRODUCT(*id),
 520                          USB_ID_VENDOR(dst), USB_ID_PRODUCT(dst));
 521                 *id = dst;
 522                 return true;
 523         }
 524
 525         return false;
 526 }
 527
 528 static const struct usb_device_id usb_audio_ids[]; /* defined below */
 529
 530 /* look for the corresponding quirk */
 531 static const struct snd_usb_audio_quirk *
 532 get_alias_quirk(struct usb_device *dev, unsigned int id)
 533 {
 534         const struct usb_device_id *p;
 535
 536         for (p = usb_audio_ids; p->match_flags; p++) {
 537                 /* FIXME: this checks only vendor:product pair in the list */
 538                 if ((p->match_flags & USB_DEVICE_ID_MATCH_DEVICE) ==
 539                     USB_DEVICE_ID_MATCH_DEVICE &&
 540                     p->idVendor == USB_ID_VENDOR(id) &&
 541                     p->idProduct == USB_ID_PRODUCT(id))
 542                         return (const struct snd_usb_audio_quirk *)p->driver_info;
 543         }
 544
 545         return NULL;
 546 }
 547
 548 /*
 549  * probe the active usb device
 550  *
 551  * note that this can be called multiple times per a device, when it
 552  * includes multiple audio control interfaces.
 553  *
 554  * thus we check the usb device pointer and creates the card instance
 555  * only at the first time.  the successive calls of this function will
 556  * append the pcm interface to the corresponding card.
 557  */
 558 static int usb_audio_probe(struct usb_interface *intf,
 559                            const struct usb_device_id *usb_id)
 560 {
 561         struct usb_device *dev = interface_to_usbdev(intf);
 562         const struct snd_usb_audio_quirk *quirk =
 563                 (const struct snd_usb_audio_quirk *)usb_id->driver_info;
 564         struct snd_usb_audio *chip;
 565         int i, err;
 566         struct usb_host_interface *alts;
 567         int ifnum;
 568         u32 id;
 569
 570         alts = &intf->altsetting[0];
 571         ifnum = get_iface_desc(alts)->bInterfaceNumber;
 572         id = USB_ID(le16_to_cpu(dev->descriptor.idVendor),
 573                     le16_to_cpu(dev->descriptor.idProduct));
 574         if (get_alias_id(dev, &id))
 575                 quirk = get_alias_quirk(dev, id);
 576         if (quirk && quirk->ifnum >= 0 && ifnum != quirk->ifnum)
 577                 return -ENXIO;
 578
 579         err = snd_usb_apply_boot_quirk(dev, intf, quirk, id);
 580         if (err < 0)
 581                 return err;
 582
 583         /*
 584          * found a config.  now register to ALSA
 585          */
 586
 587         /* check whether it's already registered */
 588         chip = NULL;
 589         mutex_lock(&register_mutex);
 590         for (i = 0; i < SNDRV_CARDS; i++) {
 591                 if (usb_chip[i] && usb_chip[i]->dev == dev) {
 592                         if (atomic_read(&usb_chip[i]->shutdown)) {
 593                                 dev_err(&dev->dev, "USB device is in the shutdown state, cannot create a card instance\n");
 594                                 err = -EIO;
 595                                 goto __error;
 596                         }
 597                         chip = usb_chip[i];
 598                         atomic_inc(&chip->active); /* avoid autopm */
 599                         break;
 600                 }
 601         }
 602         if (! chip) {
 603                 /* it's a fresh one.
 604                  * now look for an empty slot and create a new card instance
 605                  */
 606                 for (i = 0; i < SNDRV_CARDS; i++)
 607                         if (!usb_chip[i] &&
 608                             (vid[i] == -1 || vid[i] == USB_ID_VENDOR(id)) &&
 609                             (pid[i] == -1 || pid[i] == USB_ID_PRODUCT(id))) {
 610                                 if (enable[i]) {
 611                                         err = snd_usb_audio_create(intf, dev, i, quirk,
 612                                                                    id, &chip);
 613                                         if (err < 0)
 614                                                 goto __error;
 615                                         chip->pm_intf = intf;
 616                                         break;
 617                                 } else if (vid[i] != -1 || pid[i] != -1) {
 618                                         dev_info(&dev->dev,
 619                                                  "device (%04x:%04x) is disabled\n",
 620                                                  USB_ID_VENDOR(id),
 621                                                  USB_ID_PRODUCT(id));
 622                                         err = -ENOENT;
 623                                         goto __error;
 624                                 }
 625                         }
 626                 if (!chip) {
 627                         dev_err(&dev->dev, "no available usb audio device\n");
 628                         err = -ENODEV;
 629                         goto __error;
 630                 }
 631         }
 632         dev_set_drvdata(&dev->dev, chip);
 633
 634         /*
 635          * For devices with more than one control interface, we assume the
 636          * first contains the audio controls. We might need a more specific
 637          * check here in the future.
 638          */
 639         if (!chip->ctrl_intf)
 640                 chip->ctrl_intf = alts;
 641
 642         chip->txfr_quirk = 0;
 643         err = 1; /* continue */
 644         if (quirk && quirk->ifnum != QUIRK_NO_INTERFACE) {
 645                 /* need some special handlings */
 646                 err = snd_usb_create_quirk(chip, intf, &usb_audio_driver, quirk);
 647                 if (err < 0)
 648                         goto __error;
 649         }
 650
 651         if (err > 0) {
 652                 /* create normal USB audio interfaces */
 653                 err = snd_usb_create_streams(chip, ifnum);
 654                 if (err < 0)
 655                         goto __error;
 656                 err = snd_usb_create_mixer(chip, ifnum, ignore_ctl_error);
 657                 if (err < 0)
 658                         goto __error;
 659         }
 660
 661         /* we are allowed to call snd_card_register() many times */
 662         err = snd_card_register(chip->card);
 663         if (err < 0)
 664                 goto __error;
 665
 666         if (quirk && quirk->shares_media_device) {
 667                 /* don't want to fail when snd_media_device_create() fails */
 668                 snd_media_device_create(chip, intf);
 669         }
 670
 671         usb_chip[chip->index] = chip;
 672         chip->num_interfaces++;
 673         usb_set_intfdata(intf, chip);
 674         atomic_dec(&chip->active);
 675         mutex_unlock(&register_mutex);
 676         return 0;
 677
 678  __error:
 679         if (chip) {
 680                 /* chip->active is inside the chip->card object,
 681                  * decrement before memory is possibly returned.
 682                  */
 683                 atomic_dec(&chip->active);
 684                 if (!chip->num_interfaces)
 685                         snd_card_free(chip->card);
 686         }
 687         mutex_unlock(&register_mutex);
 688         return err;
 689 }
 690
 691 /*
 692  * we need to take care of counter, since disconnection can be called also
 693  * many times as well as usb_audio_probe().
 694  */
 695 static void usb_audio_disconnect(struct usb_interface *intf)
 696 {
 697         struct snd_usb_audio *chip = usb_get_intfdata(intf);
 698         struct snd_card *card;
 699         struct list_head *p;
 700
 701         if (chip == (void *)-1L)
 702                 return;
 703
 704         card = chip->card;
 705
 706         mutex_lock(&register_mutex);
 707         if (atomic_inc_return(&chip->shutdown) == 1) {
 708                 struct snd_usb_stream *as;
 709                 struct snd_usb_endpoint *ep;
 710                 struct usb_mixer_interface *mixer;
 711
 712                 /* wait until all pending tasks done;
 713                  * they are protected by snd_usb_lock_shutdown()
 714                  */
 715                 wait_event(chip->shutdown_wait,
 716                            !atomic_read(&chip->usage_count));
 717                 snd_card_disconnect(card);
 718                 /* release the pcm resources */
 719                 list_for_each_entry(as, &chip->pcm_list, list) {
 720                         snd_usb_stream_disconnect(as);
 721                 }
 722                 /* release the endpoint resources */
 723                 list_for_each_entry(ep, &chip->ep_list, list) {
 724                         snd_usb_endpoint_release(ep);
 725                 }
 726                 /* release the midi resources */
 727                 list_for_each(p, &chip->midi_list) {
 728                         snd_usbmidi_disconnect(p);
 729                 }
 730                 /*
 731                  * Nice to check quirk && quirk->shares_media_device and
 732                  * then call the snd_media_device_delete(). Don't have
 733                  * access to the quirk here. snd_media_device_delete()
 734                  * accesses mixer_list
 735                  */
 736                 snd_media_device_delete(chip);
 737
 738                 /* release mixer resources */
 739                 list_for_each_entry(mixer, &chip->mixer_list, list) {
 740                         snd_usb_mixer_disconnect(mixer);
 741                 }
 742         }
 743
 744         chip->num_interfaces--;
 745         if (chip->num_interfaces <= 0) {
 746                 usb_chip[chip->index] = NULL;
 747                 mutex_unlock(&register_mutex);
 748                 snd_card_free_when_closed(card);
 749         } else {
 750                 mutex_unlock(&register_mutex);
 751         }
 752 }
 753
 754 /* lock the shutdown (disconnect) task and autoresume */
 755 int snd_usb_lock_shutdown(struct snd_usb_audio *chip)
 756 {
 757         int err;
 758
 759         atomic_inc(&chip->usage_count);
 760         if (atomic_read(&chip->shutdown)) {
 761                 err = -EIO;
 762                 goto error;
 763         }
 764         err = snd_usb_autoresume(chip);
 765         if (err < 0)
 766                 goto error;
 767         return 0;
 768
 769  error:
 770         if (atomic_dec_and_test(&chip->usage_count))
 771                 wake_up(&chip->shutdown_wait);
 772         return err;
 773 }
 774
 775 /* autosuspend and unlock the shutdown */
 776 void snd_usb_unlock_shutdown(struct snd_usb_audio *chip)
 777 {
 778         snd_usb_autosuspend(chip);
 779         if (atomic_dec_and_test(&chip->usage_count))
 780                 wake_up(&chip->shutdown_wait);
 781 }
 782
 783 #ifdef CONFIG_PM
 784
 785 int snd_usb_autoresume(struct snd_usb_audio *chip)
 786 {
 787         if (atomic_read(&chip->shutdown))
 788                 return -EIO;
 789         if (atomic_inc_return(&chip->active) == 1)
 790                 return usb_autopm_get_interface(chip->pm_intf);
 791         return 0;
 792 }
 793
 794 void snd_usb_autosuspend(struct snd_usb_audio *chip)
 795 {
 796         if (atomic_read(&chip->shutdown))
 797                 return;
 798         if (atomic_dec_and_test(&chip->active))
 799                 usb_autopm_put_interface(chip->pm_intf);
 800 }
 801
 802 static int usb_audio_suspend(struct usb_interface *intf, pm_message_t message)
 803 {
 804         struct snd_usb_audio *chip = usb_get_intfdata(intf);
 805         struct snd_usb_stream *as;
 806         struct usb_mixer_interface *mixer;
 807         struct list_head *p;
 808
 809         if (chip == (void *)-1L)
 810                 return 0;
 811
 812         chip->autosuspended = !!PMSG_IS_AUTO(message);
 813         if (!chip->autosuspended)
 814                 snd_power_change_state(chip->card, SNDRV_CTL_POWER_D3hot);
 815         if (!chip->num_suspended_intf++) {
 816                 list_for_each_entry(as, &chip->pcm_list, list) {
 817                         snd_usb_pcm_suspend(as);
 818                         as->substream[0].need_setup_ep =
 819                                 as->substream[1].need_setup_ep = true;
 820                 }
 821                 list_for_each(p, &chip->midi_list)
 822                         snd_usbmidi_suspend(p);
 823                 list_for_each_entry(mixer, &chip->mixer_list, list)
 824                         snd_usb_mixer_suspend(mixer);
 825         }
 826
 827         return 0;
 828 }
 829
 830 static int __usb_audio_resume(struct usb_interface *intf, bool reset_resume)
 831 {
 832         struct snd_usb_audio *chip = usb_get_intfdata(intf);
 833         struct snd_usb_stream *as;
 834         struct usb_mixer_interface *mixer;
 835         struct list_head *p;
 836         int err = 0;
 837
 838         if (chip == (void *)-1L)
 839                 return 0;
 840         if (--chip->num_suspended_intf)
 841                 return 0;
 842
 843         atomic_inc(&chip->active); /* avoid autopm */
 844
 845         list_for_each_entry(as, &chip->pcm_list, list) {
 846                 err = snd_usb_pcm_resume(as);
 847                 if (err < 0)
 848                         goto err_out;
 849         }
 850
 851         /*
 852          * ALSA leaves material resumption to user space
 853          * we just notify and restart the mixers
 854          */
 855         list_for_each_entry(mixer, &chip->mixer_list, list) {
 856                 err = snd_usb_mixer_resume(mixer, reset_resume);
 857                 if (err < 0)
 858                         goto err_out;
 859         }
 860
 861         list_for_each(p, &chip->midi_list) {
 862                 snd_usbmidi_resume(p);
 863         }
 864
 865         if (!chip->autosuspended)
 866                 snd_power_change_state(chip->card, SNDRV_CTL_POWER_D0);
 867         chip->autosuspended = 0;
 868
 869 err_out:
 870         atomic_dec(&chip->active); /* allow autopm after this point */
 871         return err;
 872 }
 873
 874 static int usb_audio_resume(struct usb_interface *intf)
 875 {
 876         return __usb_audio_resume(intf, false);
 877 }
 878
 879 static int usb_audio_reset_resume(struct usb_interface *intf)
 880 {
 881         return __usb_audio_resume(intf, true);
 882 }
 883 #else
 884 #define usb_audio_suspend       NULL
 885 #define usb_audio_resume        NULL
 886 #define usb_audio_reset_resume  NULL
 887 #endif          /* CONFIG_PM */
 888
 889 static const struct usb_device_id usb_audio_ids [] = {
 890 #include "quirks-table.h"
 891     { .match_flags = (USB_DEVICE_ID_MATCH_INT_CLASS | USB_DEVICE_ID_MATCH_INT_SUBCLASS),
 892       .bInterfaceClass = USB_CLASS_AUDIO,
 893       .bInterfaceSubClass = USB_SUBCLASS_AUDIOCONTROL },
 894     { }                                         /* Terminating entry */
 895 };
 896 MODULE_DEVICE_TABLE(usb, usb_audio_ids);
 897
 898 /*
 899  * entry point for linux usb interface
 900  */
 901
 902 static struct usb_driver usb_audio_driver = {
 903         .name =         "snd-usb-audio",
 904         .probe =        usb_audio_probe,
 905         .disconnect =   usb_audio_disconnect,
 906         .suspend =      usb_audio_suspend,
 907         .resume =       usb_audio_resume,
 908         .reset_resume = usb_audio_reset_resume,
 909         .id_table =     usb_audio_ids,
 910         .supports_autosuspend = 1,
 911 };
 912
 913 module_usb_driver(usb_audio_driver);