1/* 2 * (Tentative) USB Audio Driver for ALSA 3 * 4 * Copyright (c) 2002 by Takashi Iwai <tiwai@suse.de> 5 * 6 * Many codes borrowed from audio.c by 7 * Alan Cox (alan@lxorguk.ukuu.org.uk) 8 * Thomas Sailer (sailer@ife.ee.ethz.ch) 9 * 10 * 11 * This program is free software; you can redistribute it and/or modify 12 * it under the terms of the GNU General Public License as published by 13 * the Free Software Foundation; either version 2 of the License, or 14 * (at your option) any later version. 15 * 16 * This program is distributed in the hope that it will be useful, 17 * but WITHOUT ANY WARRANTY; without even the implied warranty of 18 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 19 * GNU General Public License for more details. 20 * 21 * You should have received a copy of the GNU General Public License 22 * along with this program; if not, write to the Free Software 23 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA 24 * 25 * 26 * NOTES: 27 * 28 * - async unlink should be used for avoiding the sleep inside lock. 29 * 2.4.22 usb-uhci seems buggy for async unlinking and results in 30 * oops. in such a cse, pass async_unlink=0 option. 31 * - the linked URBs would be preferred but not used so far because of 32 * the instability of unlinking. 33 * - type II is not supported properly. there is no device which supports 34 * this type *correctly*. SB extigy looks as if it supports, but it's 35 * indeed an AC3 stream packed in SPDIF frames (i.e. no real AC3 stream). 36 */ 37 38 39#include <linux/bitops.h> 40#include <linux/init.h> 41#include <linux/list.h> 42#include <linux/slab.h> 43#include <linux/string.h> 44#include <linux/ctype.h> 45#include <linux/usb.h> 46#include <linux/moduleparam.h> 47#include <linux/mutex.h> 48#include <linux/usb/audio.h> 49#include <linux/usb/audio-v2.h> 50 51#include <sound/control.h> 52#include <sound/core.h> 53#include <sound/info.h> 54#include <sound/pcm.h> 55#include <sound/pcm_params.h> 56#include <sound/initval.h> 57 58#include "usbaudio.h" 59#include "card.h" 60#include "midi.h" 61#include "mixer.h" 62#include "proc.h" 63#include "quirks.h" 64#include "endpoint.h" 65#include "helper.h" 66#include "debug.h" 67#include "pcm.h" 68#include "urb.h" 69#include "format.h" 70#include "power.h" 71 72MODULE_AUTHOR("Takashi Iwai <tiwai@suse.de>"); 73MODULE_DESCRIPTION("USB Audio"); 74MODULE_LICENSE("GPL"); 75MODULE_SUPPORTED_DEVICE("{{Generic,USB Audio}}"); 76 77 78static int index[SNDRV_CARDS] = SNDRV_DEFAULT_IDX; /* Index 0-MAX */ 79static char *id[SNDRV_CARDS] = SNDRV_DEFAULT_STR; /* ID for this card */ 80static int enable[SNDRV_CARDS] = SNDRV_DEFAULT_ENABLE_PNP;/* Enable this card */ 81/* Vendor/product IDs for this card */ 82static int vid[SNDRV_CARDS] = { [0 ... (SNDRV_CARDS-1)] = -1 }; 83static int pid[SNDRV_CARDS] = { [0 ... (SNDRV_CARDS-1)] = -1 }; 84static int nrpacks = 8; /* max. number of packets per urb */ 85static int async_unlink = 1; 86static int device_setup[SNDRV_CARDS]; /* device parameter for this card */ 87static int ignore_ctl_error; 88 89module_param_array(index, int, NULL, 0444); 90MODULE_PARM_DESC(index, "Index value for the USB audio adapter."); 91module_param_array(id, charp, NULL, 0444); 92MODULE_PARM_DESC(id, "ID string for the USB audio adapter."); 93module_param_array(enable, bool, NULL, 0444); 94MODULE_PARM_DESC(enable, "Enable USB audio adapter."); 95module_param_array(vid, int, NULL, 0444); 96MODULE_PARM_DESC(vid, "Vendor ID for the USB audio device."); 97module_param_array(pid, int, NULL, 0444); 98MODULE_PARM_DESC(pid, "Product ID for the USB audio device."); 99module_param(nrpacks, int, 0644); 100MODULE_PARM_DESC(nrpacks, "Max. number of packets per URB."); 101module_param(async_unlink, bool, 0444); 102MODULE_PARM_DESC(async_unlink, "Use async unlink mode."); 103module_param_array(device_setup, int, NULL, 0444); 104MODULE_PARM_DESC(device_setup, "Specific device setup (if needed)."); 105module_param(ignore_ctl_error, bool, 0444); 106MODULE_PARM_DESC(ignore_ctl_error, 107 "Ignore errors from USB controller for mixer interfaces."); 108 109/* 110 * we keep the snd_usb_audio_t instances by ourselves for merging 111 * the all interfaces on the same card as one sound device. 112 */ 113 114static DEFINE_MUTEX(register_mutex); 115static struct snd_usb_audio *usb_chip[SNDRV_CARDS]; 116static struct usb_driver usb_audio_driver; 117 118/* 119 * disconnect streams 120 * called from snd_usb_audio_disconnect() 121 */ 122static void snd_usb_stream_disconnect(struct list_head *head) 123{ 124 int idx; 125 struct snd_usb_stream *as; 126 struct snd_usb_substream *subs; 127 128 as = list_entry(head, struct snd_usb_stream, list); 129 for (idx = 0; idx < 2; idx++) { 130 subs = &as->substream[idx]; 131 if (!subs->num_formats) 132 continue; 133 snd_usb_release_substream_urbs(subs, 1); 134 subs->interface = -1; 135 } 136} 137 138static int snd_usb_create_stream(struct snd_usb_audio *chip, int ctrlif, int interface) 139{ 140 struct usb_device *dev = chip->dev; 141 struct usb_host_interface *alts; 142 struct usb_interface_descriptor *altsd; 143 struct usb_interface *iface = usb_ifnum_to_if(dev, interface); 144 145 if (!iface) { 146 snd_printk(KERN_ERR "%d:%u:%d : does not exist\n", 147 dev->devnum, ctrlif, interface); 148 return -EINVAL; 149 } 150 151 if (usb_interface_claimed(iface)) { 152 snd_printdd(KERN_INFO "%d:%d:%d: skipping, already claimed\n", 153 dev->devnum, ctrlif, interface); 154 return -EINVAL; 155 } 156 157 alts = &iface->altsetting[0]; 158 altsd = get_iface_desc(alts); 159 if ((altsd->bInterfaceClass == USB_CLASS_AUDIO || 160 altsd->bInterfaceClass == USB_CLASS_VENDOR_SPEC) && 161 altsd->bInterfaceSubClass == USB_SUBCLASS_MIDISTREAMING) { 162 int err = snd_usbmidi_create(chip->card, iface, 163 &chip->midi_list, NULL); 164 if (err < 0) { 165 snd_printk(KERN_ERR "%d:%u:%d: cannot create sequencer device\n", 166 dev->devnum, ctrlif, interface); 167 return -EINVAL; 168 } 169 usb_driver_claim_interface(&usb_audio_driver, iface, (void *)-1L); 170 171 return 0; 172 } 173 174 if ((altsd->bInterfaceClass != USB_CLASS_AUDIO && 175 altsd->bInterfaceClass != USB_CLASS_VENDOR_SPEC) || 176 altsd->bInterfaceSubClass != USB_SUBCLASS_AUDIOSTREAMING) { 177 snd_printdd(KERN_ERR "%d:%u:%d: skipping non-supported interface %d\n", 178 dev->devnum, ctrlif, interface, altsd->bInterfaceClass); 179 /* skip non-supported classes */ 180 return -EINVAL; 181 } 182 183 if (snd_usb_get_speed(dev) == USB_SPEED_LOW) { 184 snd_printk(KERN_ERR "low speed audio streaming not supported\n"); 185 return -EINVAL; 186 } 187 188 if (! snd_usb_parse_audio_endpoints(chip, interface)) { 189 usb_set_interface(dev, interface, 0); /* reset the current interface */ 190 usb_driver_claim_interface(&usb_audio_driver, iface, (void *)-1L); 191 return -EINVAL; 192 } 193 194 return 0; 195} 196 197/* 198 * parse audio control descriptor and create pcm/midi streams 199 */ 200static int snd_usb_create_streams(struct snd_usb_audio *chip, int ctrlif) 201{ 202 struct usb_device *dev = chip->dev; 203 struct usb_host_interface *host_iface; 204 struct usb_interface_descriptor *altsd; 205 void *control_header; 206 int i, protocol; 207 208 /* find audiocontrol interface */ 209 host_iface = &usb_ifnum_to_if(dev, ctrlif)->altsetting[0]; 210 control_header = snd_usb_find_csint_desc(host_iface->extra, 211 host_iface->extralen, 212 NULL, UAC_HEADER); 213 altsd = get_iface_desc(host_iface); 214 protocol = altsd->bInterfaceProtocol; 215 216 if (!control_header) { 217 snd_printk(KERN_ERR "cannot find UAC_HEADER\n"); 218 return -EINVAL; 219 } 220 221 switch (protocol) { 222 default: 223 snd_printdd(KERN_WARNING "unknown interface protocol %#02x, assuming v1\n", 224 protocol); 225 /* fall through */ 226 227 case UAC_VERSION_1: { 228 struct uac1_ac_header_descriptor *h1 = control_header; 229 230 if (!h1->bInCollection) { 231 snd_printk(KERN_INFO "skipping empty audio interface (v1)\n"); 232 return -EINVAL; 233 } 234 235 if (h1->bLength < sizeof(*h1) + h1->bInCollection) { 236 snd_printk(KERN_ERR "invalid UAC_HEADER (v1)\n"); 237 return -EINVAL; 238 } 239 240 for (i = 0; i < h1->bInCollection; i++) 241 snd_usb_create_stream(chip, ctrlif, h1->baInterfaceNr[i]); 242 243 break; 244 } 245 246 case UAC_VERSION_2: { 247 struct usb_interface_assoc_descriptor *assoc = 248 usb_ifnum_to_if(dev, ctrlif)->intf_assoc; 249 250 if (!assoc) { 251 snd_printk(KERN_ERR "Audio class v2 interfaces need an interface association\n"); 252 return -EINVAL; 253 } 254 255 for (i = 0; i < assoc->bInterfaceCount; i++) { 256 int intf = assoc->bFirstInterface + i; 257 258 if (intf != ctrlif) 259 snd_usb_create_stream(chip, ctrlif, intf); 260 } 261 262 break; 263 } 264 } 265 266 return 0; 267} 268 269/* 270 * free the chip instance 271 * 272 * here we have to do not much, since pcm and controls are already freed 273 * 274 */ 275 276static int snd_usb_audio_free(struct snd_usb_audio *chip) 277{ 278 kfree(chip); 279 return 0; 280} 281 282static int snd_usb_audio_dev_free(struct snd_device *device) 283{ 284 struct snd_usb_audio *chip = device->device_data; 285 return snd_usb_audio_free(chip); 286} 287 288static void remove_trailing_spaces(char *str) 289{ 290 char *p; 291 292 if (!*str) 293 return; 294 for (p = str + strlen(str) - 1; p >= str && isspace(*p); p--) 295 *p = 0; 296} 297 298/* 299 * create a chip instance and set its names. 300 */ 301static int snd_usb_audio_create(struct usb_device *dev, int idx, 302 const struct snd_usb_audio_quirk *quirk, 303 struct snd_usb_audio **rchip) 304{ 305 struct snd_card *card; 306 struct snd_usb_audio *chip; 307 int err, len; 308 char component[14]; 309 static struct snd_device_ops ops = { 310 .dev_free = snd_usb_audio_dev_free, 311 }; 312 313 *rchip = NULL; 314 315 switch (snd_usb_get_speed(dev)) { 316 case USB_SPEED_LOW: 317 case USB_SPEED_FULL: 318 case USB_SPEED_HIGH: 319 case USB_SPEED_SUPER: 320 break; 321 default: 322 snd_printk(KERN_ERR "unknown device speed %d\n", snd_usb_get_speed(dev)); 323 return -ENXIO; 324 } 325 326 err = snd_card_create(index[idx], id[idx], THIS_MODULE, 0, &card); 327 if (err < 0) { 328 snd_printk(KERN_ERR "cannot create card instance %d\n", idx); 329 return err; 330 } 331 332 chip = kzalloc(sizeof(*chip), GFP_KERNEL); 333 if (! chip) { 334 snd_card_free(card); 335 return -ENOMEM; 336 } 337 338 mutex_init(&chip->shutdown_mutex); 339 chip->index = idx; 340 chip->dev = dev; 341 chip->card = card; 342 chip->setup = device_setup[idx]; 343 chip->nrpacks = nrpacks; 344 chip->async_unlink = async_unlink; 345 chip->probing = 1; 346 347 chip->usb_id = USB_ID(le16_to_cpu(dev->descriptor.idVendor), 348 le16_to_cpu(dev->descriptor.idProduct)); 349 INIT_LIST_HEAD(&chip->pcm_list); 350 INIT_LIST_HEAD(&chip->midi_list); 351 INIT_LIST_HEAD(&chip->mixer_list); 352 353 if ((err = snd_device_new(card, SNDRV_DEV_LOWLEVEL, chip, &ops)) < 0) { 354 snd_usb_audio_free(chip); 355 snd_card_free(card); 356 return err; 357 } 358 359 strcpy(card->driver, "USB-Audio"); 360 sprintf(component, "USB%04x:%04x", 361 USB_ID_VENDOR(chip->usb_id), USB_ID_PRODUCT(chip->usb_id)); 362 snd_component_add(card, component); 363 364 /* retrieve the device string as shortname */ 365 if (quirk && quirk->product_name && *quirk->product_name) { 366 strlcpy(card->shortname, quirk->product_name, sizeof(card->shortname)); 367 } else { 368 if (!dev->descriptor.iProduct || 369 usb_string(dev, dev->descriptor.iProduct, 370 card->shortname, sizeof(card->shortname)) <= 0) { 371 /* no name available from anywhere, so use ID */ 372 sprintf(card->shortname, "USB Device %#04x:%#04x", 373 USB_ID_VENDOR(chip->usb_id), 374 USB_ID_PRODUCT(chip->usb_id)); 375 } 376 } 377 remove_trailing_spaces(card->shortname); 378 379 /* retrieve the vendor and device strings as longname */ 380 if (quirk && quirk->vendor_name && *quirk->vendor_name) { 381 len = strlcpy(card->longname, quirk->vendor_name, sizeof(card->longname)); 382 } else { 383 if (dev->descriptor.iManufacturer) 384 len = usb_string(dev, dev->descriptor.iManufacturer, 385 card->longname, sizeof(card->longname)); 386 else 387 len = 0; 388 /* we don't really care if there isn't any vendor string */ 389 } 390 if (len > 0) { 391 remove_trailing_spaces(card->longname); 392 if (*card->longname) 393 strlcat(card->longname, " ", sizeof(card->longname)); 394 } 395 396 strlcat(card->longname, card->shortname, sizeof(card->longname)); 397 398 len = strlcat(card->longname, " at ", sizeof(card->longname)); 399 400 if (len < sizeof(card->longname)) 401 usb_make_path(dev, card->longname + len, sizeof(card->longname) - len); 402 403 switch (snd_usb_get_speed(dev)) { 404 case USB_SPEED_LOW: 405 strlcat(card->longname, ", low speed", sizeof(card->longname)); 406 break; 407 case USB_SPEED_FULL: 408 strlcat(card->longname, ", full speed", sizeof(card->longname)); 409 break; 410 case USB_SPEED_HIGH: 411 strlcat(card->longname, ", high speed", sizeof(card->longname)); 412 break; 413 case USB_SPEED_SUPER: 414 strlcat(card->longname, ", super speed", sizeof(card->longname)); 415 break; 416 default: 417 break; 418 } 419 420 snd_usb_audio_create_proc(chip); 421 422 *rchip = chip; 423 return 0; 424} 425 426/* 427 * probe the active usb device 428 * 429 * note that this can be called multiple times per a device, when it 430 * includes multiple audio control interfaces. 431 * 432 * thus we check the usb device pointer and creates the card instance 433 * only at the first time. the successive calls of this function will 434 * append the pcm interface to the corresponding card. 435 */ 436static void *snd_usb_audio_probe(struct usb_device *dev, 437 struct usb_interface *intf, 438 const struct usb_device_id *usb_id) 439{ 440 const struct snd_usb_audio_quirk *quirk = (const struct snd_usb_audio_quirk *)usb_id->driver_info; 441 int i, err; 442 struct snd_usb_audio *chip; 443 struct usb_host_interface *alts; 444 int ifnum; 445 u32 id; 446 447 alts = &intf->altsetting[0]; 448 ifnum = get_iface_desc(alts)->bInterfaceNumber; 449 id = USB_ID(le16_to_cpu(dev->descriptor.idVendor), 450 le16_to_cpu(dev->descriptor.idProduct)); 451 if (quirk && quirk->ifnum >= 0 && ifnum != quirk->ifnum) 452 goto __err_val; 453 454 if (snd_usb_apply_boot_quirk(dev, intf, quirk) < 0) 455 goto __err_val; 456 457 /* 458 * found a config. now register to ALSA 459 */ 460 461 /* check whether it's already registered */ 462 chip = NULL; 463 mutex_lock(®ister_mutex); 464 for (i = 0; i < SNDRV_CARDS; i++) { 465 if (usb_chip[i] && usb_chip[i]->dev == dev) { 466 if (usb_chip[i]->shutdown) { 467 snd_printk(KERN_ERR "USB device is in the shutdown state, cannot create a card instance\n"); 468 goto __error; 469 } 470 chip = usb_chip[i]; 471 chip->probing = 1; 472 break; 473 } 474 } 475 if (! chip) { 476 /* it's a fresh one. 477 * now look for an empty slot and create a new card instance 478 */ 479 for (i = 0; i < SNDRV_CARDS; i++) 480 if (enable[i] && ! usb_chip[i] && 481 (vid[i] == -1 || vid[i] == USB_ID_VENDOR(id)) && 482 (pid[i] == -1 || pid[i] == USB_ID_PRODUCT(id))) { 483 if (snd_usb_audio_create(dev, i, quirk, &chip) < 0) { 484 goto __error; 485 } 486 snd_card_set_dev(chip->card, &intf->dev); 487 chip->pm_intf = intf; 488 break; 489 } 490 if (!chip) { 491 printk(KERN_ERR "no available usb audio device\n"); 492 goto __error; 493 } 494 } 495 496 /* 497 * For devices with more than one control interface, we assume the 498 * first contains the audio controls. We might need a more specific 499 * check here in the future. 500 */ 501 if (!chip->ctrl_intf) 502 chip->ctrl_intf = alts; 503 504 chip->txfr_quirk = 0; 505 err = 1; /* continue */ 506 if (quirk && quirk->ifnum != QUIRK_NO_INTERFACE) { 507 /* need some special handlings */ 508 if ((err = snd_usb_create_quirk(chip, intf, &usb_audio_driver, quirk)) < 0) 509 goto __error; 510 } 511 512 if (err > 0) { 513 /* create normal USB audio interfaces */ 514 if (snd_usb_create_streams(chip, ifnum) < 0 || 515 snd_usb_create_mixer(chip, ifnum, ignore_ctl_error) < 0) { 516 goto __error; 517 } 518 } 519 520 /* we are allowed to call snd_card_register() many times */ 521 if (snd_card_register(chip->card) < 0) { 522 goto __error; 523 } 524 525 usb_chip[chip->index] = chip; 526 chip->num_interfaces++; 527 chip->probing = 0; 528 mutex_unlock(®ister_mutex); 529 return chip; 530 531 __error: 532 if (chip) { 533 if (!chip->num_interfaces) 534 snd_card_free(chip->card); 535 chip->probing = 0; 536 } 537 mutex_unlock(®ister_mutex); 538 __err_val: 539 return NULL; 540} 541 542/* 543 * we need to take care of counter, since disconnection can be called also 544 * many times as well as usb_audio_probe(). 545 */ 546static void snd_usb_audio_disconnect(struct usb_device *dev, void *ptr) 547{ 548 struct snd_usb_audio *chip; 549 struct snd_card *card; 550 struct list_head *p; 551 552 if (ptr == (void *)-1L) 553 return; 554 555 chip = ptr; 556 card = chip->card; 557 mutex_lock(®ister_mutex); 558 mutex_lock(&chip->shutdown_mutex); 559 chip->shutdown = 1; 560 chip->num_interfaces--; 561 if (chip->num_interfaces <= 0) { 562 snd_card_disconnect(card); 563 /* release the pcm resources */ 564 list_for_each(p, &chip->pcm_list) { 565 snd_usb_stream_disconnect(p); 566 } 567 /* release the midi resources */ 568 list_for_each(p, &chip->midi_list) { 569 snd_usbmidi_disconnect(p); 570 } 571 /* release mixer resources */ 572 list_for_each(p, &chip->mixer_list) { 573 snd_usb_mixer_disconnect(p); 574 } 575 usb_chip[chip->index] = NULL; 576 mutex_unlock(&chip->shutdown_mutex); 577 mutex_unlock(®ister_mutex); 578 snd_card_free_when_closed(card); 579 } else { 580 mutex_unlock(&chip->shutdown_mutex); 581 mutex_unlock(®ister_mutex); 582 } 583} 584 585/* 586 * new 2.5 USB kernel API 587 */ 588static int usb_audio_probe(struct usb_interface *intf, 589 const struct usb_device_id *id) 590{ 591 void *chip; 592 chip = snd_usb_audio_probe(interface_to_usbdev(intf), intf, id); 593 if (chip) { 594 usb_set_intfdata(intf, chip); 595 return 0; 596 } else 597 return -EIO; 598} 599 600static void usb_audio_disconnect(struct usb_interface *intf) 601{ 602 snd_usb_audio_disconnect(interface_to_usbdev(intf), 603 usb_get_intfdata(intf)); 604} 605 606#ifdef CONFIG_PM 607 608int snd_usb_autoresume(struct snd_usb_audio *chip) 609{ 610 int err = -ENODEV; 611 612 if (!chip->shutdown && !chip->probing) 613 err = usb_autopm_get_interface(chip->pm_intf); 614 615 return err; 616} 617 618void snd_usb_autosuspend(struct snd_usb_audio *chip) 619{ 620 if (!chip->shutdown && !chip->probing) 621 usb_autopm_put_interface(chip->pm_intf); 622} 623 624static int usb_audio_suspend(struct usb_interface *intf, pm_message_t message) 625{ 626 struct snd_usb_audio *chip = usb_get_intfdata(intf); 627 struct list_head *p; 628 struct snd_usb_stream *as; 629 struct usb_mixer_interface *mixer; 630 631 if (chip == (void *)-1L) 632 return 0; 633 634 if (!(message.event & PM_EVENT_AUTO)) { 635 snd_power_change_state(chip->card, SNDRV_CTL_POWER_D3hot); 636 if (!chip->num_suspended_intf++) { 637 list_for_each(p, &chip->pcm_list) { 638 as = list_entry(p, struct snd_usb_stream, list); 639 snd_pcm_suspend_all(as->pcm); 640 } 641 } 642 } else { 643 /* 644 * otherwise we keep the rest of the system in the dark 645 * to keep this transparent 646 */ 647 if (!chip->num_suspended_intf++) 648 chip->autosuspended = 1; 649 } 650 651 list_for_each_entry(mixer, &chip->mixer_list, list) 652 snd_usb_mixer_inactivate(mixer); 653 654 return 0; 655} 656 657static int usb_audio_resume(struct usb_interface *intf) 658{ 659 struct snd_usb_audio *chip = usb_get_intfdata(intf); 660 struct usb_mixer_interface *mixer; 661 int err = 0; 662 663 if (chip == (void *)-1L) 664 return 0; 665 if (--chip->num_suspended_intf) 666 return 0; 667 /* 668 * ALSA leaves material resumption to user space 669 * we just notify and restart the mixers 670 */ 671 list_for_each_entry(mixer, &chip->mixer_list, list) { 672 err = snd_usb_mixer_activate(mixer); 673 if (err < 0) 674 goto err_out; 675 } 676 677 if (!chip->autosuspended) 678 snd_power_change_state(chip->card, SNDRV_CTL_POWER_D0); 679 chip->autosuspended = 0; 680 681err_out: 682 return err; 683} 684#else 685#define usb_audio_suspend NULL 686#define usb_audio_resume NULL 687#endif /* CONFIG_PM */ 688 689static struct usb_device_id usb_audio_ids [] = { 690#include "quirks-table.h" 691 { .match_flags = (USB_DEVICE_ID_MATCH_INT_CLASS | USB_DEVICE_ID_MATCH_INT_SUBCLASS), 692 .bInterfaceClass = USB_CLASS_AUDIO, 693 .bInterfaceSubClass = USB_SUBCLASS_AUDIOCONTROL }, 694 { } /* Terminating entry */ 695}; 696 697MODULE_DEVICE_TABLE (usb, usb_audio_ids); 698 699/* 700 * entry point for linux usb interface 701 */ 702 703static struct usb_driver usb_audio_driver = { 704 .name = "snd-usb-audio", 705 .probe = usb_audio_probe, 706 .disconnect = usb_audio_disconnect, 707 .suspend = usb_audio_suspend, 708 .resume = usb_audio_resume, 709 .id_table = usb_audio_ids, 710 .supports_autosuspend = 1, 711}; 712 713static int __init snd_usb_audio_init(void) 714{ 715 if (nrpacks < 1 || nrpacks > MAX_PACKS) { 716 printk(KERN_WARNING "invalid nrpacks value.\n"); 717 return -EINVAL; 718 } 719 return usb_register(&usb_audio_driver); 720} 721 722static void __exit snd_usb_audio_cleanup(void) 723{ 724 usb_deregister(&usb_audio_driver); 725} 726 727module_init(snd_usb_audio_init); 728module_exit(snd_usb_audio_cleanup); 729