drivers/net/wireless/rt2x00/rt2x00usb.c

   1 /*
   2         Copyright (C) 2004 - 2008 rt2x00 SourceForge Project
   3         <http://rt2x00.serialmonkey.com>
   4
   5         This program is free software; you can redistribute it and/or modify
   6         it under the terms of the GNU General Public License as published by
   7         the Free Software Foundation; either version 2 of the License, or
   8         (at your option) any later version.
   9
  10         This program is distributed in the hope that it will be useful,
  11         but WITHOUT ANY WARRANTY; without even the implied warranty of
  12         MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
  13         GNU General Public License for more details.
  14
  15         You should have received a copy of the GNU General Public License
  16         along with this program; if not, write to the
  17         Free Software Foundation, Inc.,
  18         59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
  19  */
  20
  21 /*
  22         Module: rt2x00usb
  23         Abstract: rt2x00 generic usb device routines.
  24  */
  25
  26 #include <linux/kernel.h>
  27 #include <linux/module.h>
  28 #include <linux/usb.h>
  29 #include <linux/bug.h>
  30
  31 #include "rt2x00.h"
  32 #include "rt2x00usb.h"
  33
  34 /*
  35  * Interfacing with the HW.
  36  */
  37 int rt2x00usb_vendor_request(struct rt2x00_dev *rt2x00dev,
  38                              const u8 request, const u8 requesttype,
  39                              const u16 offset, const u16 value,
  40                              void *buffer, const u16 buffer_length,
  41                              const int timeout)
  42 {
  43         struct usb_device *usb_dev = to_usb_device_intf(rt2x00dev->dev);
  44         int status;
  45         unsigned int i;
  46         unsigned int pipe =
  47             (requesttype == USB_VENDOR_REQUEST_IN) ?
  48             usb_rcvctrlpipe(usb_dev, 0) : usb_sndctrlpipe(usb_dev, 0);
  49
  50
  51         for (i = 0; i < REGISTER_BUSY_COUNT; i++) {
  52                 status = usb_control_msg(usb_dev, pipe, request, requesttype,
  53                                          value, offset, buffer, buffer_length,
  54                                          timeout);
  55                 if (status >= 0)
  56                         return 0;
  57
  58                 /*
  59                  * Check for errors
  60                  * -ENODEV: Device has disappeared, no point continuing.
  61                  * All other errors: Try again.
  62                  */
  63                 else if (status == -ENODEV)
  64                         break;
  65         }
  66
  67         ERROR(rt2x00dev,
  68               "Vendor Request 0x%02x failed for offset 0x%04x with error %d.\n",
  69               request, offset, status);
  70
  71         return status;
  72 }
  73 EXPORT_SYMBOL_GPL(rt2x00usb_vendor_request);
  74
  75 int rt2x00usb_vendor_req_buff_lock(struct rt2x00_dev *rt2x00dev,
  76                                    const u8 request, const u8 requesttype,
  77                                    const u16 offset, void *buffer,
  78                                    const u16 buffer_length, const int timeout)
  79 {
  80         int status;
  81
  82         BUG_ON(!mutex_is_locked(&rt2x00dev->usb_cache_mutex));
  83
  84         /*
  85          * Check for Cache availability.
  86          */
  87         if (unlikely(!rt2x00dev->csr.cache || buffer_length > CSR_CACHE_SIZE)) {
  88                 ERROR(rt2x00dev, "CSR cache not available.\n");
  89                 return -ENOMEM;
  90         }
  91
  92         if (requesttype == USB_VENDOR_REQUEST_OUT)
  93                 memcpy(rt2x00dev->csr.cache, buffer, buffer_length);
  94
  95         status = rt2x00usb_vendor_request(rt2x00dev, request, requesttype,
  96                                           offset, 0, rt2x00dev->csr.cache,
  97                                           buffer_length, timeout);
  98
  99         if (!status && requesttype == USB_VENDOR_REQUEST_IN)
 100                 memcpy(buffer, rt2x00dev->csr.cache, buffer_length);
 101
 102         return status;
 103 }
 104 EXPORT_SYMBOL_GPL(rt2x00usb_vendor_req_buff_lock);
 105
 106 int rt2x00usb_vendor_request_buff(struct rt2x00_dev *rt2x00dev,
 107                                   const u8 request, const u8 requesttype,
 108                                   const u16 offset, void *buffer,
 109                                   const u16 buffer_length, const int timeout)
 110 {
 111         int status;
 112
 113         mutex_lock(&rt2x00dev->usb_cache_mutex);
 114
 115         status = rt2x00usb_vendor_req_buff_lock(rt2x00dev, request,
 116                                                 requesttype, offset, buffer,
 117                                                 buffer_length, timeout);
 118
 119         mutex_unlock(&rt2x00dev->usb_cache_mutex);
 120
 121         return status;
 122 }
 123 EXPORT_SYMBOL_GPL(rt2x00usb_vendor_request_buff);
 124
 125 int rt2x00usb_vendor_request_large_buff(struct rt2x00_dev *rt2x00dev,
 126                                         const u8 request, const u8 requesttype,
 127                                         const u16 offset, const void *buffer,
 128                                         const u16 buffer_length,
 129                                         const int timeout)
 130 {
 131         int status = 0;
 132         unsigned char *tb;
 133         u16 off, len, bsize;
 134
 135         mutex_lock(&rt2x00dev->usb_cache_mutex);
 136
 137         tb  = (char *)buffer;
 138         off = offset;
 139         len = buffer_length;
 140         while (len && !status) {
 141                 bsize = min_t(u16, CSR_CACHE_SIZE, len);
 142                 status = rt2x00usb_vendor_req_buff_lock(rt2x00dev, request,
 143                                                         requesttype, off, tb,
 144                                                         bsize, timeout);
 145
 146                 tb  += bsize;
 147                 len -= bsize;
 148                 off += bsize;
 149         }
 150
 151         mutex_unlock(&rt2x00dev->usb_cache_mutex);
 152
 153         return status;
 154 }
 155 EXPORT_SYMBOL_GPL(rt2x00usb_vendor_request_large_buff);
 156
 157 /*
 158  * TX data handlers.
 159  */
 160 static void rt2x00usb_interrupt_txdone(struct urb *urb)
 161 {
 162         struct queue_entry *entry = (struct queue_entry *)urb->context;
 163         struct rt2x00_dev *rt2x00dev = entry->queue->rt2x00dev;
 164         struct txdone_entry_desc txdesc;
 165
 166         if (!test_bit(DEVICE_STATE_ENABLED_RADIO, &rt2x00dev->flags) ||
 167             !test_bit(ENTRY_OWNER_DEVICE_DATA, &entry->flags))
 168                 return;
 169
 170         /*
 171          * Obtain the status about this packet.
 172          * Note that when the status is 0 it does not mean the
 173          * frame was send out correctly. It only means the frame
 174          * was succesfully pushed to the hardware, we have no
 175          * way to determine the transmission status right now.
 176          * (Only indirectly by looking at the failed TX counters
 177          * in the register).
 178          */
 179         txdesc.flags = 0;
 180         if (!urb->status)
 181                 __set_bit(TXDONE_UNKNOWN, &txdesc.flags);
 182         else
 183                 __set_bit(TXDONE_FAILURE, &txdesc.flags);
 184         txdesc.retry = 0;
 185
 186         rt2x00lib_txdone(entry, &txdesc);
 187 }
 188
 189 int rt2x00usb_write_tx_data(struct queue_entry *entry)
 190 {
 191         struct rt2x00_dev *rt2x00dev = entry->queue->rt2x00dev;
 192         struct usb_device *usb_dev = to_usb_device_intf(rt2x00dev->dev);
 193         struct queue_entry_priv_usb *entry_priv = entry->priv_data;
 194         struct skb_frame_desc *skbdesc;
 195         u32 length;
 196
 197         /*
 198          * Add the descriptor in front of the skb.
 199          */
 200         skb_push(entry->skb, entry->queue->desc_size);
 201         memset(entry->skb->data, 0, entry->queue->desc_size);
 202
 203         /*
 204          * Fill in skb descriptor
 205          */
 206         skbdesc = get_skb_frame_desc(entry->skb);
 207         skbdesc->desc = entry->skb->data;
 208         skbdesc->desc_len = entry->queue->desc_size;
 209
 210         /*
 211          * USB devices cannot blindly pass the skb->len as the
 212          * length of the data to usb_fill_bulk_urb. Pass the skb
 213          * to the driver to determine what the length should be.
 214          */
 215         length = rt2x00dev->ops->lib->get_tx_data_len(rt2x00dev, entry->skb);
 216
 217         usb_fill_bulk_urb(entry_priv->urb, usb_dev,
 218                           usb_sndbulkpipe(usb_dev, 1),
 219                           entry->skb->data, length,
 220                           rt2x00usb_interrupt_txdone, entry);
 221
 222         /*
 223          * Make sure the skb->data pointer points to the frame, not the
 224          * descriptor.
 225          */
 226         skb_pull(entry->skb, entry->queue->desc_size);
 227
 228         return 0;
 229 }
 230 EXPORT_SYMBOL_GPL(rt2x00usb_write_tx_data);
 231
 232 static inline void rt2x00usb_kick_tx_entry(struct queue_entry *entry)
 233 {
 234         struct queue_entry_priv_usb *entry_priv = entry->priv_data;
 235
 236         if (test_and_clear_bit(ENTRY_DATA_PENDING, &entry->flags))
 237                 usb_submit_urb(entry_priv->urb, GFP_ATOMIC);
 238 }
 239
 240 void rt2x00usb_kick_tx_queue(struct rt2x00_dev *rt2x00dev,
 241                              const enum data_queue_qid qid)
 242 {
 243         struct data_queue *queue = rt2x00queue_get_queue(rt2x00dev, qid);
 244         unsigned long irqflags;
 245         unsigned int index;
 246         unsigned int index_done;
 247         unsigned int i;
 248
 249         /*
 250          * Only protect the range we are going to loop over,
 251          * if during our loop a extra entry is set to pending
 252          * it should not be kicked during this run, since it
 253          * is part of another TX operation.
 254          */
 255         spin_lock_irqsave(&queue->lock, irqflags);
 256         index = queue->index[Q_INDEX];
 257         index_done = queue->index[Q_INDEX_DONE];
 258         spin_unlock_irqrestore(&queue->lock, irqflags);
 259
 260         /*
 261          * Start from the TX done pointer, this guarentees that we will
 262          * send out all frames in the correct order.
 263          */
 264         if (index_done < index) {
 265                 for (i = index_done; i < index; i++)
 266                         rt2x00usb_kick_tx_entry(&queue->entries[i]);
 267         } else {
 268                 for (i = index_done; i < queue->limit; i++)
 269                         rt2x00usb_kick_tx_entry(&queue->entries[i]);
 270
 271                 for (i = 0; i < index; i++)
 272                         rt2x00usb_kick_tx_entry(&queue->entries[i]);
 273         }
 274 }
 275 EXPORT_SYMBOL_GPL(rt2x00usb_kick_tx_queue);
 276
 277 /*
 278  * RX data handlers.
 279  */
 280 static void rt2x00usb_interrupt_rxdone(struct urb *urb)
 281 {
 282         struct queue_entry *entry = (struct queue_entry *)urb->context;
 283         struct rt2x00_dev *rt2x00dev = entry->queue->rt2x00dev;
 284         struct skb_frame_desc *skbdesc = get_skb_frame_desc(entry->skb);
 285         u8 rxd[32];
 286
 287         if (!test_bit(DEVICE_STATE_ENABLED_RADIO, &rt2x00dev->flags) ||
 288             !test_bit(ENTRY_OWNER_DEVICE_DATA, &entry->flags))
 289                 return;
 290
 291         /*
 292          * Check if the received data is simply too small
 293          * to be actually valid, or if the urb is signaling
 294          * a problem.
 295          */
 296         if (urb->actual_length < entry->queue->desc_size || urb->status) {
 297                 set_bit(ENTRY_OWNER_DEVICE_DATA, &entry->flags);
 298                 usb_submit_urb(urb, GFP_ATOMIC);
 299                 return;
 300         }
 301
 302         /*
 303          * Fill in desc fields of the skb descriptor
 304          */
 305         skbdesc->desc = rxd;
 306         skbdesc->desc_len = entry->queue->desc_size;
 307
 308         /*
 309          * Send the frame to rt2x00lib for further processing.
 310          */
 311         rt2x00lib_rxdone(rt2x00dev, entry);
 312 }
 313
 314 /*
 315  * Radio handlers
 316  */
 317 void rt2x00usb_disable_radio(struct rt2x00_dev *rt2x00dev)
 318 {
 319         struct queue_entry_priv_usb *entry_priv;
 320         struct queue_entry_priv_usb_bcn *bcn_priv;
 321         struct data_queue *queue;
 322         unsigned int i;
 323
 324         rt2x00usb_vendor_request_sw(rt2x00dev, USB_RX_CONTROL, 0, 0,
 325                                     REGISTER_TIMEOUT);
 326
 327         /*
 328          * Cancel all queues.
 329          */
 330         queue_for_each(rt2x00dev, queue) {
 331                 for (i = 0; i < queue->limit; i++) {
 332                         entry_priv = queue->entries[i].priv_data;
 333                         usb_kill_urb(entry_priv->urb);
 334                 }
 335         }
 336
 337         /*
 338          * Kill guardian urb (if required by driver).
 339          */
 340         if (!test_bit(DRIVER_REQUIRE_BEACON_GUARD, &rt2x00dev->flags))
 341                 return;
 342
 343         for (i = 0; i < rt2x00dev->bcn->limit; i++) {
 344                 bcn_priv = rt2x00dev->bcn->entries[i].priv_data;
 345                 if (bcn_priv->guardian_urb)
 346                         usb_kill_urb(bcn_priv->guardian_urb);
 347         }
 348 }
 349 EXPORT_SYMBOL_GPL(rt2x00usb_disable_radio);
 350
 351 /*
 352  * Device initialization handlers.
 353  */
 354 void rt2x00usb_init_rxentry(struct rt2x00_dev *rt2x00dev,
 355                             struct queue_entry *entry)
 356 {
 357         struct usb_device *usb_dev = to_usb_device_intf(rt2x00dev->dev);
 358         struct queue_entry_priv_usb *entry_priv = entry->priv_data;
 359
 360         usb_fill_bulk_urb(entry_priv->urb, usb_dev,
 361                           usb_rcvbulkpipe(usb_dev, 1),
 362                           entry->skb->data, entry->skb->len,
 363                           rt2x00usb_interrupt_rxdone, entry);
 364
 365         set_bit(ENTRY_OWNER_DEVICE_DATA, &entry->flags);
 366         usb_submit_urb(entry_priv->urb, GFP_ATOMIC);
 367 }
 368 EXPORT_SYMBOL_GPL(rt2x00usb_init_rxentry);
 369
 370 void rt2x00usb_init_txentry(struct rt2x00_dev *rt2x00dev,
 371                             struct queue_entry *entry)
 372 {
 373         entry->flags = 0;
 374 }
 375 EXPORT_SYMBOL_GPL(rt2x00usb_init_txentry);
 376
 377 static int rt2x00usb_alloc_urb(struct rt2x00_dev *rt2x00dev,
 378                                struct data_queue *queue)
 379 {
 380         struct queue_entry_priv_usb *entry_priv;
 381         struct queue_entry_priv_usb_bcn *bcn_priv;
 382         unsigned int i;
 383
 384         for (i = 0; i < queue->limit; i++) {
 385                 entry_priv = queue->entries[i].priv_data;
 386                 entry_priv->urb = usb_alloc_urb(0, GFP_KERNEL);
 387                 if (!entry_priv->urb)
 388                         return -ENOMEM;
 389         }
 390
 391         /*
 392          * If this is not the beacon queue or
 393          * no guardian byte was required for the beacon,
 394          * then we are done.
 395          */
 396         if (rt2x00dev->bcn != queue ||
 397             !test_bit(DRIVER_REQUIRE_BEACON_GUARD, &rt2x00dev->flags))
 398                 return 0;
 399
 400         for (i = 0; i < queue->limit; i++) {
 401                 bcn_priv = queue->entries[i].priv_data;
 402                 bcn_priv->guardian_urb = usb_alloc_urb(0, GFP_KERNEL);
 403                 if (!bcn_priv->guardian_urb)
 404                         return -ENOMEM;
 405         }
 406
 407         return 0;
 408 }
 409
 410 static void rt2x00usb_free_urb(struct rt2x00_dev *rt2x00dev,
 411                                struct data_queue *queue)
 412 {
 413         struct queue_entry_priv_usb *entry_priv;
 414         struct queue_entry_priv_usb_bcn *bcn_priv;
 415         unsigned int i;
 416
 417         if (!queue->entries)
 418                 return;
 419
 420         for (i = 0; i < queue->limit; i++) {
 421                 entry_priv = queue->entries[i].priv_data;
 422                 usb_kill_urb(entry_priv->urb);
 423                 usb_free_urb(entry_priv->urb);
 424         }
 425
 426         /*
 427          * If this is not the beacon queue or
 428          * no guardian byte was required for the beacon,
 429          * then we are done.
 430          */
 431         if (rt2x00dev->bcn != queue ||
 432             !test_bit(DRIVER_REQUIRE_BEACON_GUARD, &rt2x00dev->flags))
 433                 return;
 434
 435         for (i = 0; i < queue->limit; i++) {
 436                 bcn_priv = queue->entries[i].priv_data;
 437                 usb_kill_urb(bcn_priv->guardian_urb);
 438                 usb_free_urb(bcn_priv->guardian_urb);
 439         }
 440 }
 441
 442 int rt2x00usb_initialize(struct rt2x00_dev *rt2x00dev)
 443 {
 444         struct data_queue *queue;
 445         int status;
 446
 447         /*
 448          * Allocate DMA
 449          */
 450         queue_for_each(rt2x00dev, queue) {
 451                 status = rt2x00usb_alloc_urb(rt2x00dev, queue);
 452                 if (status)
 453                         goto exit;
 454         }
 455
 456         return 0;
 457
 458 exit:
 459         rt2x00usb_uninitialize(rt2x00dev);
 460
 461         return status;
 462 }
 463 EXPORT_SYMBOL_GPL(rt2x00usb_initialize);
 464
 465 void rt2x00usb_uninitialize(struct rt2x00_dev *rt2x00dev)
 466 {
 467         struct data_queue *queue;
 468
 469         queue_for_each(rt2x00dev, queue)
 470                 rt2x00usb_free_urb(rt2x00dev, queue);
 471 }
 472 EXPORT_SYMBOL_GPL(rt2x00usb_uninitialize);
 473
 474 /*
 475  * USB driver handlers.
 476  */
 477 static void rt2x00usb_free_reg(struct rt2x00_dev *rt2x00dev)
 478 {
 479         kfree(rt2x00dev->rf);
 480         rt2x00dev->rf = NULL;
 481
 482         kfree(rt2x00dev->eeprom);
 483         rt2x00dev->eeprom = NULL;
 484
 485         kfree(rt2x00dev->csr.cache);
 486         rt2x00dev->csr.cache = NULL;
 487 }
 488
 489 static int rt2x00usb_alloc_reg(struct rt2x00_dev *rt2x00dev)
 490 {
 491         rt2x00dev->csr.cache = kzalloc(CSR_CACHE_SIZE, GFP_KERNEL);
 492         if (!rt2x00dev->csr.cache)
 493                 goto exit;
 494
 495         rt2x00dev->eeprom = kzalloc(rt2x00dev->ops->eeprom_size, GFP_KERNEL);
 496         if (!rt2x00dev->eeprom)
 497                 goto exit;
 498
 499         rt2x00dev->rf = kzalloc(rt2x00dev->ops->rf_size, GFP_KERNEL);
 500         if (!rt2x00dev->rf)
 501                 goto exit;
 502
 503         return 0;
 504
 505 exit:
 506         ERROR_PROBE("Failed to allocate registers.\n");
 507
 508         rt2x00usb_free_reg(rt2x00dev);
 509
 510         return -ENOMEM;
 511 }
 512
 513 int rt2x00usb_probe(struct usb_interface *usb_intf,
 514                     const struct usb_device_id *id)
 515 {
 516         struct usb_device *usb_dev = interface_to_usbdev(usb_intf);
 517         struct rt2x00_ops *ops = (struct rt2x00_ops *)id->driver_info;
 518         struct ieee80211_hw *hw;
 519         struct rt2x00_dev *rt2x00dev;
 520         int retval;
 521
 522         usb_dev = usb_get_dev(usb_dev);
 523
 524         hw = ieee80211_alloc_hw(sizeof(struct rt2x00_dev), ops->hw);
 525         if (!hw) {
 526                 ERROR_PROBE("Failed to allocate hardware.\n");
 527                 retval = -ENOMEM;
 528                 goto exit_put_device;
 529         }
 530
 531         usb_set_intfdata(usb_intf, hw);
 532
 533         rt2x00dev = hw->priv;
 534         rt2x00dev->dev = &usb_intf->dev;
 535         rt2x00dev->ops = ops;
 536         rt2x00dev->hw = hw;
 537         mutex_init(&rt2x00dev->usb_cache_mutex);
 538
 539         rt2x00dev->usb_maxpacket =
 540             usb_maxpacket(usb_dev, usb_sndbulkpipe(usb_dev, 1), 1);
 541         if (!rt2x00dev->usb_maxpacket)
 542                 rt2x00dev->usb_maxpacket = 1;
 543
 544         retval = rt2x00usb_alloc_reg(rt2x00dev);
 545         if (retval)
 546                 goto exit_free_device;
 547
 548         retval = rt2x00lib_probe_dev(rt2x00dev);
 549         if (retval)
 550                 goto exit_free_reg;
 551
 552         return 0;
 553
 554 exit_free_reg:
 555         rt2x00usb_free_reg(rt2x00dev);
 556
 557 exit_free_device:
 558         ieee80211_free_hw(hw);
 559
 560 exit_put_device:
 561         usb_put_dev(usb_dev);
 562
 563         usb_set_intfdata(usb_intf, NULL);
 564
 565         return retval;
 566 }
 567 EXPORT_SYMBOL_GPL(rt2x00usb_probe);
 568
 569 void rt2x00usb_disconnect(struct usb_interface *usb_intf)
 570 {
 571         struct ieee80211_hw *hw = usb_get_intfdata(usb_intf);
 572         struct rt2x00_dev *rt2x00dev = hw->priv;
 573
 574         /*
 575          * Free all allocated data.
 576          */
 577         rt2x00lib_remove_dev(rt2x00dev);
 578         rt2x00usb_free_reg(rt2x00dev);
 579         ieee80211_free_hw(hw);
 580
 581         /*
 582          * Free the USB device data.
 583          */
 584         usb_set_intfdata(usb_intf, NULL);
 585         usb_put_dev(interface_to_usbdev(usb_intf));
 586 }
 587 EXPORT_SYMBOL_GPL(rt2x00usb_disconnect);
 588
 589 #ifdef CONFIG_PM
 590 int rt2x00usb_suspend(struct usb_interface *usb_intf, pm_message_t state)
 591 {
 592         struct ieee80211_hw *hw = usb_get_intfdata(usb_intf);
 593         struct rt2x00_dev *rt2x00dev = hw->priv;
 594         int retval;
 595
 596         retval = rt2x00lib_suspend(rt2x00dev, state);
 597         if (retval)
 598                 return retval;
 599
 600         rt2x00usb_free_reg(rt2x00dev);
 601
 602         /*
 603          * Decrease usbdev refcount.
 604          */
 605         usb_put_dev(interface_to_usbdev(usb_intf));
 606
 607         return 0;
 608 }
 609 EXPORT_SYMBOL_GPL(rt2x00usb_suspend);
 610
 611 int rt2x00usb_resume(struct usb_interface *usb_intf)
 612 {
 613         struct ieee80211_hw *hw = usb_get_intfdata(usb_intf);
 614         struct rt2x00_dev *rt2x00dev = hw->priv;
 615         int retval;
 616
 617         usb_get_dev(interface_to_usbdev(usb_intf));
 618
 619         retval = rt2x00usb_alloc_reg(rt2x00dev);
 620         if (retval)
 621                 return retval;
 622
 623         retval = rt2x00lib_resume(rt2x00dev);
 624         if (retval)
 625                 goto exit_free_reg;
 626
 627         return 0;
 628
 629 exit_free_reg:
 630         rt2x00usb_free_reg(rt2x00dev);
 631
 632         return retval;
 633 }
 634 EXPORT_SYMBOL_GPL(rt2x00usb_resume);
 635 #endif /* CONFIG_PM */
 636
 637 /*
 638  * rt2x00usb module information.
 639  */
 640 MODULE_AUTHOR(DRV_PROJECT);
 641 MODULE_VERSION(DRV_VERSION);
 642 MODULE_DESCRIPTION("rt2x00 usb library");
 643 MODULE_LICENSE("GPL");