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