linux/sound/usb/card.c
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   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
  70MODULE_AUTHOR("Takashi Iwai <tiwai@suse.de>");
  71MODULE_DESCRIPTION("USB Audio");
  72MODULE_LICENSE("GPL");
  73MODULE_SUPPORTED_DEVICE("{{Generic,USB Audio}}");
  74
  75
  76static int index[SNDRV_CARDS] = SNDRV_DEFAULT_IDX;      /* Index 0-MAX */
  77static char *id[SNDRV_CARDS] = SNDRV_DEFAULT_STR;       /* ID for this card */
  78static bool enable[SNDRV_CARDS] = SNDRV_DEFAULT_ENABLE_PNP;/* Enable this card */
  79/* Vendor/product IDs for this card */
  80static int vid[SNDRV_CARDS] = { [0 ... (SNDRV_CARDS-1)] = -1 };
  81static int pid[SNDRV_CARDS] = { [0 ... (SNDRV_CARDS-1)] = -1 };
  82static int device_setup[SNDRV_CARDS]; /* device parameter for this card */
  83static bool ignore_ctl_error;
  84static bool autoclock = true;
  85
  86module_param_array(index, int, NULL, 0444);
  87MODULE_PARM_DESC(index, "Index value for the USB audio adapter.");
  88module_param_array(id, charp, NULL, 0444);
  89MODULE_PARM_DESC(id, "ID string for the USB audio adapter.");
  90module_param_array(enable, bool, NULL, 0444);
  91MODULE_PARM_DESC(enable, "Enable USB audio adapter.");
  92module_param_array(vid, int, NULL, 0444);
  93MODULE_PARM_DESC(vid, "Vendor ID for the USB audio device.");
  94module_param_array(pid, int, NULL, 0444);
  95MODULE_PARM_DESC(pid, "Product ID for the USB audio device.");
  96module_param_array(device_setup, int, NULL, 0444);
  97MODULE_PARM_DESC(device_setup, "Specific device setup (if needed).");
  98module_param(ignore_ctl_error, bool, 0444);
  99MODULE_PARM_DESC(ignore_ctl_error,
 100                 "Ignore errors from USB controller for mixer interfaces.");
 101module_param(autoclock, bool, 0444);
 102MODULE_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
 109static DEFINE_MUTEX(register_mutex);
 110static struct snd_usb_audio *usb_chip[SNDRV_CARDS];
 111static struct usb_driver usb_audio_driver;
 112
 113/*
 114 * disconnect streams
 115 * called from usb_audio_disconnect()
 116 */
 117static 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
 132static 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 */
 214static 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
 306static 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
 318static 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 */
 327static 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_waitqueue_head(&chip->shutdown_wait);
 369        chip->index = idx;
 370        chip->dev = dev;
 371        chip->card = card;
 372        chip->setup = device_setup[idx];
 373        chip->autoclock = autoclock;
 374        atomic_set(&chip->active, 1); /* avoid autopm during probing */
 375        atomic_set(&chip->usage_count, 0);
 376        atomic_set(&chip->shutdown, 0);
 377
 378        chip->usb_id = USB_ID(le16_to_cpu(dev->descriptor.idVendor),
 379                              le16_to_cpu(dev->descriptor.idProduct));
 380        INIT_LIST_HEAD(&chip->pcm_list);
 381        INIT_LIST_HEAD(&chip->ep_list);
 382        INIT_LIST_HEAD(&chip->midi_list);
 383        INIT_LIST_HEAD(&chip->mixer_list);
 384
 385        if ((err = snd_device_new(card, SNDRV_DEV_LOWLEVEL, chip, &ops)) < 0) {
 386                snd_usb_audio_free(chip);
 387                snd_card_free(card);
 388                return err;
 389        }
 390
 391        strcpy(card->driver, "USB-Audio");
 392        sprintf(component, "USB%04x:%04x",
 393                USB_ID_VENDOR(chip->usb_id), USB_ID_PRODUCT(chip->usb_id));
 394        snd_component_add(card, component);
 395
 396        /* retrieve the device string as shortname */
 397        if (quirk && quirk->product_name && *quirk->product_name) {
 398                strlcpy(card->shortname, quirk->product_name, sizeof(card->shortname));
 399        } else {
 400                if (!dev->descriptor.iProduct ||
 401                    usb_string(dev, dev->descriptor.iProduct,
 402                    card->shortname, sizeof(card->shortname)) <= 0) {
 403                        /* no name available from anywhere, so use ID */
 404                        sprintf(card->shortname, "USB Device %#04x:%#04x",
 405                                USB_ID_VENDOR(chip->usb_id),
 406                                USB_ID_PRODUCT(chip->usb_id));
 407                }
 408        }
 409        strim(card->shortname);
 410
 411        /* retrieve the vendor and device strings as longname */
 412        if (quirk && quirk->vendor_name && *quirk->vendor_name) {
 413                len = strlcpy(card->longname, quirk->vendor_name, sizeof(card->longname));
 414        } else {
 415                if (dev->descriptor.iManufacturer)
 416                        len = usb_string(dev, dev->descriptor.iManufacturer,
 417                                         card->longname, sizeof(card->longname));
 418                else
 419                        len = 0;
 420                /* we don't really care if there isn't any vendor string */
 421        }
 422        if (len > 0) {
 423                strim(card->longname);
 424                if (*card->longname)
 425                        strlcat(card->longname, " ", sizeof(card->longname));
 426        }
 427
 428        strlcat(card->longname, card->shortname, sizeof(card->longname));
 429
 430        len = strlcat(card->longname, " at ", sizeof(card->longname));
 431
 432        if (len < sizeof(card->longname))
 433                usb_make_path(dev, card->longname + len, sizeof(card->longname) - len);
 434
 435        switch (snd_usb_get_speed(dev)) {
 436        case USB_SPEED_LOW:
 437                strlcat(card->longname, ", low speed", sizeof(card->longname));
 438                break;
 439        case USB_SPEED_FULL:
 440                strlcat(card->longname, ", full speed", sizeof(card->longname));
 441                break;
 442        case USB_SPEED_HIGH:
 443                strlcat(card->longname, ", high speed", sizeof(card->longname));
 444                break;
 445        case USB_SPEED_SUPER:
 446                strlcat(card->longname, ", super speed", sizeof(card->longname));
 447                break;
 448        default:
 449                break;
 450        }
 451
 452        snd_usb_audio_create_proc(chip);
 453
 454        *rchip = chip;
 455        return 0;
 456}
 457
 458/*
 459 * probe the active usb device
 460 *
 461 * note that this can be called multiple times per a device, when it
 462 * includes multiple audio control interfaces.
 463 *
 464 * thus we check the usb device pointer and creates the card instance
 465 * only at the first time.  the successive calls of this function will
 466 * append the pcm interface to the corresponding card.
 467 */
 468static int usb_audio_probe(struct usb_interface *intf,
 469                           const struct usb_device_id *usb_id)
 470{
 471        struct usb_device *dev = interface_to_usbdev(intf);
 472        const struct snd_usb_audio_quirk *quirk =
 473                (const struct snd_usb_audio_quirk *)usb_id->driver_info;
 474        struct snd_usb_audio *chip;
 475        int i, err;
 476        struct usb_host_interface *alts;
 477        int ifnum;
 478        u32 id;
 479
 480        alts = &intf->altsetting[0];
 481        ifnum = get_iface_desc(alts)->bInterfaceNumber;
 482        id = USB_ID(le16_to_cpu(dev->descriptor.idVendor),
 483                    le16_to_cpu(dev->descriptor.idProduct));
 484        if (quirk && quirk->ifnum >= 0 && ifnum != quirk->ifnum)
 485                return -ENXIO;
 486
 487        err = snd_usb_apply_boot_quirk(dev, intf, quirk);
 488        if (err < 0)
 489                return err;
 490
 491        /*
 492         * found a config.  now register to ALSA
 493         */
 494
 495        /* check whether it's already registered */
 496        chip = NULL;
 497        mutex_lock(&register_mutex);
 498        for (i = 0; i < SNDRV_CARDS; i++) {
 499                if (usb_chip[i] && usb_chip[i]->dev == dev) {
 500                        if (atomic_read(&usb_chip[i]->shutdown)) {
 501                                dev_err(&dev->dev, "USB device is in the shutdown state, cannot create a card instance\n");
 502                                err = -EIO;
 503                                goto __error;
 504                        }
 505                        chip = usb_chip[i];
 506                        atomic_inc(&chip->active); /* avoid autopm */
 507                        break;
 508                }
 509        }
 510        if (! chip) {
 511                /* it's a fresh one.
 512                 * now look for an empty slot and create a new card instance
 513                 */
 514                for (i = 0; i < SNDRV_CARDS; i++)
 515                        if (enable[i] && ! usb_chip[i] &&
 516                            (vid[i] == -1 || vid[i] == USB_ID_VENDOR(id)) &&
 517                            (pid[i] == -1 || pid[i] == USB_ID_PRODUCT(id))) {
 518                                err = snd_usb_audio_create(intf, dev, i, quirk,
 519                                                           &chip);
 520                                if (err < 0)
 521                                        goto __error;
 522                                chip->pm_intf = intf;
 523                                break;
 524                        }
 525                if (!chip) {
 526                        dev_err(&dev->dev, "no available usb audio device\n");
 527                        err = -ENODEV;
 528                        goto __error;
 529                }
 530        }
 531
 532        /*
 533         * For devices with more than one control interface, we assume the
 534         * first contains the audio controls. We might need a more specific
 535         * check here in the future.
 536         */
 537        if (!chip->ctrl_intf)
 538                chip->ctrl_intf = alts;
 539
 540        chip->txfr_quirk = 0;
 541        err = 1; /* continue */
 542        if (quirk && quirk->ifnum != QUIRK_NO_INTERFACE) {
 543                /* need some special handlings */
 544                err = snd_usb_create_quirk(chip, intf, &usb_audio_driver, quirk);
 545                if (err < 0)
 546                        goto __error;
 547        }
 548
 549        if (err > 0) {
 550                /* create normal USB audio interfaces */
 551                err = snd_usb_create_streams(chip, ifnum);
 552                if (err < 0)
 553                        goto __error;
 554                err = snd_usb_create_mixer(chip, ifnum, ignore_ctl_error);
 555                if (err < 0)
 556                        goto __error;
 557        }
 558
 559        /* we are allowed to call snd_card_register() many times */
 560        err = snd_card_register(chip->card);
 561        if (err < 0)
 562                goto __error;
 563
 564        usb_chip[chip->index] = chip;
 565        chip->num_interfaces++;
 566        usb_set_intfdata(intf, chip);
 567        atomic_dec(&chip->active);
 568        mutex_unlock(&register_mutex);
 569        return 0;
 570
 571 __error:
 572        if (chip) {
 573                if (!chip->num_interfaces)
 574                        snd_card_free(chip->card);
 575                atomic_dec(&chip->active);
 576        }
 577        mutex_unlock(&register_mutex);
 578        return err;
 579}
 580
 581/*
 582 * we need to take care of counter, since disconnection can be called also
 583 * many times as well as usb_audio_probe().
 584 */
 585static void usb_audio_disconnect(struct usb_interface *intf)
 586{
 587        struct snd_usb_audio *chip = usb_get_intfdata(intf);
 588        struct snd_card *card;
 589        struct list_head *p;
 590
 591        if (chip == (void *)-1L)
 592                return;
 593
 594        card = chip->card;
 595
 596        mutex_lock(&register_mutex);
 597        if (atomic_inc_return(&chip->shutdown) == 1) {
 598                struct snd_usb_stream *as;
 599                struct snd_usb_endpoint *ep;
 600                struct usb_mixer_interface *mixer;
 601
 602                /* wait until all pending tasks done;
 603                 * they are protected by snd_usb_lock_shutdown()
 604                 */
 605                wait_event(chip->shutdown_wait,
 606                           !atomic_read(&chip->usage_count));
 607                snd_card_disconnect(card);
 608                /* release the pcm resources */
 609                list_for_each_entry(as, &chip->pcm_list, list) {
 610                        snd_usb_stream_disconnect(as);
 611                }
 612                /* release the endpoint resources */
 613                list_for_each_entry(ep, &chip->ep_list, list) {
 614                        snd_usb_endpoint_release(ep);
 615                }
 616                /* release the midi resources */
 617                list_for_each(p, &chip->midi_list) {
 618                        snd_usbmidi_disconnect(p);
 619                }
 620                /* release mixer resources */
 621                list_for_each_entry(mixer, &chip->mixer_list, list) {
 622                        snd_usb_mixer_disconnect(mixer);
 623                }
 624        }
 625
 626        chip->num_interfaces--;
 627        if (chip->num_interfaces <= 0) {
 628                usb_chip[chip->index] = NULL;
 629                mutex_unlock(&register_mutex);
 630                snd_card_free_when_closed(card);
 631        } else {
 632                mutex_unlock(&register_mutex);
 633        }
 634}
 635
 636/* lock the shutdown (disconnect) task and autoresume */
 637int snd_usb_lock_shutdown(struct snd_usb_audio *chip)
 638{
 639        int err;
 640
 641        atomic_inc(&chip->usage_count);
 642        if (atomic_read(&chip->shutdown)) {
 643                err = -EIO;
 644                goto error;
 645        }
 646        err = snd_usb_autoresume(chip);
 647        if (err < 0)
 648                goto error;
 649        return 0;
 650
 651 error:
 652        if (atomic_dec_and_test(&chip->usage_count))
 653                wake_up(&chip->shutdown_wait);
 654        return err;
 655}
 656
 657/* autosuspend and unlock the shutdown */
 658void snd_usb_unlock_shutdown(struct snd_usb_audio *chip)
 659{
 660        snd_usb_autosuspend(chip);
 661        if (atomic_dec_and_test(&chip->usage_count))
 662                wake_up(&chip->shutdown_wait);
 663}
 664
 665#ifdef CONFIG_PM
 666
 667int snd_usb_autoresume(struct snd_usb_audio *chip)
 668{
 669        if (atomic_read(&chip->shutdown))
 670                return -EIO;
 671        if (atomic_inc_return(&chip->active) == 1)
 672                return usb_autopm_get_interface(chip->pm_intf);
 673        return 0;
 674}
 675
 676void snd_usb_autosuspend(struct snd_usb_audio *chip)
 677{
 678        if (atomic_dec_and_test(&chip->active))
 679                usb_autopm_put_interface(chip->pm_intf);
 680}
 681
 682static int usb_audio_suspend(struct usb_interface *intf, pm_message_t message)
 683{
 684        struct snd_usb_audio *chip = usb_get_intfdata(intf);
 685        struct snd_usb_stream *as;
 686        struct usb_mixer_interface *mixer;
 687        struct list_head *p;
 688
 689        if (chip == (void *)-1L)
 690                return 0;
 691
 692        chip->autosuspended = !!PMSG_IS_AUTO(message);
 693        if (!chip->autosuspended)
 694                snd_power_change_state(chip->card, SNDRV_CTL_POWER_D3hot);
 695        if (!chip->num_suspended_intf++) {
 696                list_for_each_entry(as, &chip->pcm_list, list) {
 697                        snd_pcm_suspend_all(as->pcm);
 698                        as->substream[0].need_setup_ep =
 699                                as->substream[1].need_setup_ep = true;
 700                }
 701                list_for_each(p, &chip->midi_list)
 702                        snd_usbmidi_suspend(p);
 703                list_for_each_entry(mixer, &chip->mixer_list, list)
 704                        snd_usb_mixer_suspend(mixer);
 705        }
 706
 707        return 0;
 708}
 709
 710static int __usb_audio_resume(struct usb_interface *intf, bool reset_resume)
 711{
 712        struct snd_usb_audio *chip = usb_get_intfdata(intf);
 713        struct usb_mixer_interface *mixer;
 714        struct list_head *p;
 715        int err = 0;
 716
 717        if (chip == (void *)-1L)
 718                return 0;
 719        if (--chip->num_suspended_intf)
 720                return 0;
 721
 722        atomic_inc(&chip->active); /* avoid autopm */
 723        /*
 724         * ALSA leaves material resumption to user space
 725         * we just notify and restart the mixers
 726         */
 727        list_for_each_entry(mixer, &chip->mixer_list, list) {
 728                err = snd_usb_mixer_resume(mixer, reset_resume);
 729                if (err < 0)
 730                        goto err_out;
 731        }
 732
 733        list_for_each(p, &chip->midi_list) {
 734                snd_usbmidi_resume(p);
 735        }
 736
 737        if (!chip->autosuspended)
 738                snd_power_change_state(chip->card, SNDRV_CTL_POWER_D0);
 739        chip->autosuspended = 0;
 740
 741err_out:
 742        atomic_dec(&chip->active); /* allow autopm after this point */
 743        return err;
 744}
 745
 746static int usb_audio_resume(struct usb_interface *intf)
 747{
 748        return __usb_audio_resume(intf, false);
 749}
 750
 751static int usb_audio_reset_resume(struct usb_interface *intf)
 752{
 753        return __usb_audio_resume(intf, true);
 754}
 755#else
 756#define usb_audio_suspend       NULL
 757#define usb_audio_resume        NULL
 758#define usb_audio_reset_resume  NULL
 759#endif          /* CONFIG_PM */
 760
 761static struct usb_device_id usb_audio_ids [] = {
 762#include "quirks-table.h"
 763    { .match_flags = (USB_DEVICE_ID_MATCH_INT_CLASS | USB_DEVICE_ID_MATCH_INT_SUBCLASS),
 764      .bInterfaceClass = USB_CLASS_AUDIO,
 765      .bInterfaceSubClass = USB_SUBCLASS_AUDIOCONTROL },
 766    { }                                         /* Terminating entry */
 767};
 768MODULE_DEVICE_TABLE(usb, usb_audio_ids);
 769
 770/*
 771 * entry point for linux usb interface
 772 */
 773
 774static struct usb_driver usb_audio_driver = {
 775        .name =         "snd-usb-audio",
 776        .probe =        usb_audio_probe,
 777        .disconnect =   usb_audio_disconnect,
 778        .suspend =      usb_audio_suspend,
 779        .resume =       usb_audio_resume,
 780        .reset_resume = usb_audio_reset_resume,
 781        .id_table =     usb_audio_ids,
 782        .supports_autosuspend = 1,
 783};
 784
 785module_usb_driver(usb_audio_driver);
 786