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 = rt2x00dev_usb_dev(rt2x00dev);
  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 /*
 126  * TX data handlers.
 127  */
 128 static void rt2x00usb_interrupt_txdone(struct urb *urb)
 129 {
 130         struct queue_entry *entry = (struct queue_entry *)urb->context;
 131         struct rt2x00_dev *rt2x00dev = entry->queue->rt2x00dev;
 132         struct txdone_entry_desc txdesc;
 133         enum data_queue_qid qid = skb_get_queue_mapping(entry->skb);
 134
 135         if (!test_bit(DEVICE_ENABLED_RADIO, &rt2x00dev->flags) ||
 136             !__test_and_clear_bit(ENTRY_OWNER_DEVICE_DATA, &entry->flags))
 137                 return;
 138
 139         /*
 140          * Remove the descriptor data from the buffer.
 141          */
 142         skb_pull(entry->skb, entry->queue->desc_size);
 143
 144         /*
 145          * Obtain the status about this packet.
 146          * Note that when the status is 0 it does not mean the
 147          * frame was send out correctly. It only means the frame
 148          * was succesfully pushed to the hardware, we have no
 149          * way to determine the transmission status right now.
 150          * (Only indirectly by looking at the failed TX counters
 151          * in the register).
 152          */
 153         if (!urb->status)
 154                 __set_bit(TXDONE_UNKNOWN, &txdesc.flags);
 155         else
 156                 __set_bit(TXDONE_FAILURE, &txdesc.flags);
 157         txdesc.retry = 0;
 158
 159         rt2x00lib_txdone(entry, &txdesc);
 160
 161         /*
 162          * Make this entry available for reuse.
 163          */
 164         entry->flags = 0;
 165         rt2x00queue_index_inc(entry->queue, Q_INDEX_DONE);
 166
 167         /*
 168          * If the data queue was below the threshold before the txdone
 169          * handler we must make sure the packet queue in the mac80211 stack
 170          * is reenabled when the txdone handler has finished.
 171          */
 172         if (!rt2x00queue_threshold(entry->queue))
 173                 ieee80211_wake_queue(rt2x00dev->hw, qid);
 174 }
 175
 176 int rt2x00usb_write_tx_data(struct queue_entry *entry)
 177 {
 178         struct rt2x00_dev *rt2x00dev = entry->queue->rt2x00dev;
 179         struct usb_device *usb_dev = rt2x00dev_usb_dev(rt2x00dev);
 180         struct queue_entry_priv_usb *entry_priv = entry->priv_data;
 181         struct skb_frame_desc *skbdesc;
 182         u32 length;
 183
 184         /*
 185          * Add the descriptor in front of the skb.
 186          */
 187         skb_push(entry->skb, entry->queue->desc_size);
 188         memset(entry->skb->data, 0, entry->queue->desc_size);
 189
 190         /*
 191          * Fill in skb descriptor
 192          */
 193         skbdesc = get_skb_frame_desc(entry->skb);
 194         memset(skbdesc, 0, sizeof(*skbdesc));
 195         skbdesc->desc = entry->skb->data;
 196         skbdesc->desc_len = entry->queue->desc_size;
 197         skbdesc->entry = entry;
 198
 199         /*
 200          * USB devices cannot blindly pass the skb->len as the
 201          * length of the data to usb_fill_bulk_urb. Pass the skb
 202          * to the driver to determine what the length should be.
 203          */
 204         length = rt2x00dev->ops->lib->get_tx_data_len(rt2x00dev, entry->skb);
 205
 206         usb_fill_bulk_urb(entry_priv->urb, usb_dev,
 207                           usb_sndbulkpipe(usb_dev, 1),
 208                           entry->skb->data, length,
 209                           rt2x00usb_interrupt_txdone, entry);
 210
 211         return 0;
 212 }
 213 EXPORT_SYMBOL_GPL(rt2x00usb_write_tx_data);
 214
 215 static inline void rt2x00usb_kick_tx_entry(struct queue_entry *entry)
 216 {
 217         struct queue_entry_priv_usb *entry_priv = entry->priv_data;
 218
 219         if (__test_and_clear_bit(ENTRY_DATA_PENDING, &entry->flags))
 220                 usb_submit_urb(entry_priv->urb, GFP_ATOMIC);
 221 }
 222
 223 void rt2x00usb_kick_tx_queue(struct rt2x00_dev *rt2x00dev,
 224                              const enum data_queue_qid qid)
 225 {
 226         struct data_queue *queue = rt2x00queue_get_queue(rt2x00dev, qid);
 227         unsigned long irqflags;
 228         unsigned int index;
 229         unsigned int index_done;
 230         unsigned int i;
 231
 232         /*
 233          * Only protect the range we are going to loop over,
 234          * if during our loop a extra entry is set to pending
 235          * it should not be kicked during this run, since it
 236          * is part of another TX operation.
 237          */
 238         spin_lock_irqsave(&queue->lock, irqflags);
 239         index = queue->index[Q_INDEX];
 240         index_done = queue->index[Q_INDEX_DONE];
 241         spin_unlock_irqrestore(&queue->lock, irqflags);
 242
 243         /*
 244          * Start from the TX done pointer, this guarentees that we will
 245          * send out all frames in the correct order.
 246          */
 247         if (index_done < index) {
 248                 for (i = index_done; i < index; i++)
 249                         rt2x00usb_kick_tx_entry(&queue->entries[i]);
 250         } else {
 251                 for (i = index_done; i < queue->limit; i++)
 252                         rt2x00usb_kick_tx_entry(&queue->entries[i]);
 253
 254                 for (i = 0; i < index; i++)
 255                         rt2x00usb_kick_tx_entry(&queue->entries[i]);
 256         }
 257 }
 258 EXPORT_SYMBOL_GPL(rt2x00usb_kick_tx_queue);
 259
 260 /*
 261  * RX data handlers.
 262  */
 263 static void rt2x00usb_interrupt_rxdone(struct urb *urb)
 264 {
 265         struct queue_entry *entry = (struct queue_entry *)urb->context;
 266         struct rt2x00_dev *rt2x00dev = entry->queue->rt2x00dev;
 267         struct sk_buff *skb;
 268         struct skb_frame_desc *skbdesc;
 269         struct rxdone_entry_desc rxdesc;
 270         u8 rxd[32];
 271
 272         if (!test_bit(DEVICE_ENABLED_RADIO, &rt2x00dev->flags) ||
 273             !test_and_clear_bit(ENTRY_OWNER_DEVICE_DATA, &entry->flags))
 274                 return;
 275
 276         /*
 277          * Check if the received data is simply too small
 278          * to be actually valid, or if the urb is signaling
 279          * a problem.
 280          */
 281         if (urb->actual_length < entry->queue->desc_size || urb->status)
 282                 goto skip_entry;
 283
 284         /*
 285          * Fill in skb descriptor
 286          */
 287         skbdesc = get_skb_frame_desc(entry->skb);
 288         memset(skbdesc, 0, sizeof(*skbdesc));
 289         skbdesc->entry = entry;
 290         skbdesc->desc = rxd;
 291         skbdesc->desc_len = entry->queue->desc_size;
 292
 293         memset(&rxdesc, 0, sizeof(rxdesc));
 294         rt2x00dev->ops->lib->fill_rxdone(entry, &rxdesc);
 295
 296         /*
 297          * Allocate a new sk buffer to replace the current one.
 298          * If allocation fails, we should drop the current frame
 299          * so we can recycle the existing sk buffer for the new frame.
 300          */
 301         skb = rt2x00queue_alloc_rxskb(entry->queue);
 302         if (!skb)
 303                 goto skip_entry;
 304
 305         /*
 306          * Send the frame to rt2x00lib for further processing.
 307          */
 308         rt2x00lib_rxdone(entry, &rxdesc);
 309
 310         /*
 311          * Replace current entry's skb with the newly allocated one,
 312          * and reinitialize the urb.
 313          */
 314         entry->skb = skb;
 315         urb->transfer_buffer = entry->skb->data;
 316         urb->transfer_buffer_length = entry->skb->len;
 317
 318 skip_entry:
 319         if (test_bit(DEVICE_ENABLED_RADIO, &entry->queue->rt2x00dev->flags)) {
 320                 __set_bit(ENTRY_OWNER_DEVICE_DATA, &entry->flags);
 321                 usb_submit_urb(urb, GFP_ATOMIC);
 322         }
 323
 324         rt2x00queue_index_inc(entry->queue, Q_INDEX);
 325 }
 326
 327 /*
 328  * Radio handlers
 329  */
 330 void rt2x00usb_disable_radio(struct rt2x00_dev *rt2x00dev)
 331 {
 332         struct queue_entry_priv_usb *entry_priv;
 333         struct queue_entry_priv_usb_bcn *bcn_priv;
 334         unsigned int i;
 335
 336         rt2x00usb_vendor_request_sw(rt2x00dev, USB_RX_CONTROL, 0, 0,
 337                                     REGISTER_TIMEOUT);
 338
 339         /*
 340          * Cancel all queues.
 341          */
 342         for (i = 0; i < rt2x00dev->rx->limit; i++) {
 343                 entry_priv = rt2x00dev->rx->entries[i].priv_data;
 344                 usb_kill_urb(entry_priv->urb);
 345         }
 346
 347         /*
 348          * Kill guardian urb (if required by driver).
 349          */
 350         if (!test_bit(DRIVER_REQUIRE_BEACON_GUARD, &rt2x00dev->flags))
 351                 return;
 352
 353         for (i = 0; i < rt2x00dev->bcn->limit; i++) {
 354                 bcn_priv = rt2x00dev->bcn->entries[i].priv_data;
 355                 if (bcn_priv->guardian_urb)
 356                         usb_kill_urb(bcn_priv->guardian_urb);
 357         }
 358 }
 359 EXPORT_SYMBOL_GPL(rt2x00usb_disable_radio);
 360
 361 /*
 362  * Device initialization handlers.
 363  */
 364 void rt2x00usb_init_rxentry(struct rt2x00_dev *rt2x00dev,
 365                             struct queue_entry *entry)
 366 {
 367         struct usb_device *usb_dev = rt2x00dev_usb_dev(rt2x00dev);
 368         struct queue_entry_priv_usb *entry_priv = entry->priv_data;
 369
 370         usb_fill_bulk_urb(entry_priv->urb, usb_dev,
 371                           usb_rcvbulkpipe(usb_dev, 1),
 372                           entry->skb->data, entry->skb->len,
 373                           rt2x00usb_interrupt_rxdone, entry);
 374
 375         __set_bit(ENTRY_OWNER_DEVICE_DATA, &entry->flags);
 376         usb_submit_urb(entry_priv->urb, GFP_ATOMIC);
 377 }
 378 EXPORT_SYMBOL_GPL(rt2x00usb_init_rxentry);
 379
 380 void rt2x00usb_init_txentry(struct rt2x00_dev *rt2x00dev,
 381                             struct queue_entry *entry)
 382 {
 383         entry->flags = 0;
 384 }
 385 EXPORT_SYMBOL_GPL(rt2x00usb_init_txentry);
 386
 387 static int rt2x00usb_alloc_urb(struct rt2x00_dev *rt2x00dev,
 388                                struct data_queue *queue)
 389 {
 390         struct queue_entry_priv_usb *entry_priv;
 391         struct queue_entry_priv_usb_bcn *bcn_priv;
 392         unsigned int i;
 393
 394         for (i = 0; i < queue->limit; i++) {
 395                 entry_priv = queue->entries[i].priv_data;
 396                 entry_priv->urb = usb_alloc_urb(0, GFP_KERNEL);
 397                 if (!entry_priv->urb)
 398                         return -ENOMEM;
 399         }
 400
 401         /*
 402          * If this is not the beacon queue or
 403          * no guardian byte was required for the beacon,
 404          * then we are done.
 405          */
 406         if (rt2x00dev->bcn != queue ||
 407             !test_bit(DRIVER_REQUIRE_BEACON_GUARD, &rt2x00dev->flags))
 408                 return 0;
 409
 410         for (i = 0; i < queue->limit; i++) {
 411                 bcn_priv = queue->entries[i].priv_data;
 412                 bcn_priv->guardian_urb = usb_alloc_urb(0, GFP_KERNEL);
 413                 if (!bcn_priv->guardian_urb)
 414                         return -ENOMEM;
 415         }
 416
 417         return 0;
 418 }
 419
 420 static void rt2x00usb_free_urb(struct rt2x00_dev *rt2x00dev,
 421                                struct data_queue *queue)
 422 {
 423         struct queue_entry_priv_usb *entry_priv;
 424         struct queue_entry_priv_usb_bcn *bcn_priv;
 425         unsigned int i;
 426
 427         if (!queue->entries)
 428                 return;
 429
 430         for (i = 0; i < queue->limit; i++) {
 431                 entry_priv = queue->entries[i].priv_data;
 432                 usb_kill_urb(entry_priv->urb);
 433                 usb_free_urb(entry_priv->urb);
 434                 if (queue->entries[i].skb)
 435                         kfree_skb(queue->entries[i].skb);
 436         }
 437
 438         /*
 439          * If this is not the beacon queue or
 440          * no guardian byte was required for the beacon,
 441          * then we are done.
 442          */
 443         if (rt2x00dev->bcn != queue ||
 444             !test_bit(DRIVER_REQUIRE_BEACON_GUARD, &rt2x00dev->flags))
 445                 return;
 446
 447         for (i = 0; i < queue->limit; i++) {
 448                 bcn_priv = queue->entries[i].priv_data;
 449                 usb_kill_urb(bcn_priv->guardian_urb);
 450                 usb_free_urb(bcn_priv->guardian_urb);
 451         }
 452 }
 453
 454 int rt2x00usb_initialize(struct rt2x00_dev *rt2x00dev)
 455 {
 456         struct data_queue *queue;
 457         struct sk_buff *skb;
 458         unsigned int entry_size;
 459         unsigned int i;
 460         int uninitialized_var(status);
 461
 462         /*
 463          * Allocate DMA
 464          */
 465         queue_for_each(rt2x00dev, queue) {
 466                 status = rt2x00usb_alloc_urb(rt2x00dev, queue);
 467                 if (status)
 468                         goto exit;
 469         }
 470
 471         /*
 472          * For the RX queue, skb's should be allocated.
 473          */
 474         entry_size = rt2x00dev->rx->data_size + rt2x00dev->rx->desc_size;
 475         for (i = 0; i < rt2x00dev->rx->limit; i++) {
 476                 skb = rt2x00queue_alloc_rxskb(rt2x00dev->rx);
 477                 if (!skb)
 478                         goto exit;
 479
 480                 rt2x00dev->rx->entries[i].skb = skb;
 481         }
 482
 483         return 0;
 484
 485 exit:
 486         rt2x00usb_uninitialize(rt2x00dev);
 487
 488         return status;
 489 }
 490 EXPORT_SYMBOL_GPL(rt2x00usb_initialize);
 491
 492 void rt2x00usb_uninitialize(struct rt2x00_dev *rt2x00dev)
 493 {
 494         struct data_queue *queue;
 495
 496         queue_for_each(rt2x00dev, queue)
 497                 rt2x00usb_free_urb(rt2x00dev, queue);
 498 }
 499 EXPORT_SYMBOL_GPL(rt2x00usb_uninitialize);
 500
 501 /*
 502  * USB driver handlers.
 503  */
 504 static void rt2x00usb_free_reg(struct rt2x00_dev *rt2x00dev)
 505 {
 506         kfree(rt2x00dev->rf);
 507         rt2x00dev->rf = NULL;
 508
 509         kfree(rt2x00dev->eeprom);
 510         rt2x00dev->eeprom = NULL;
 511
 512         kfree(rt2x00dev->csr.cache);
 513         rt2x00dev->csr.cache = NULL;
 514 }
 515
 516 static int rt2x00usb_alloc_reg(struct rt2x00_dev *rt2x00dev)
 517 {
 518         rt2x00dev->csr.cache = kzalloc(CSR_CACHE_SIZE, GFP_KERNEL);
 519         if (!rt2x00dev->csr.cache)
 520                 goto exit;
 521
 522         rt2x00dev->eeprom = kzalloc(rt2x00dev->ops->eeprom_size, GFP_KERNEL);
 523         if (!rt2x00dev->eeprom)
 524                 goto exit;
 525
 526         rt2x00dev->rf = kzalloc(rt2x00dev->ops->rf_size, GFP_KERNEL);
 527         if (!rt2x00dev->rf)
 528                 goto exit;
 529
 530         return 0;
 531
 532 exit:
 533         ERROR_PROBE("Failed to allocate registers.\n");
 534
 535         rt2x00usb_free_reg(rt2x00dev);
 536
 537         return -ENOMEM;
 538 }
 539
 540 int rt2x00usb_probe(struct usb_interface *usb_intf,
 541                     const struct usb_device_id *id)
 542 {
 543         struct usb_device *usb_dev = interface_to_usbdev(usb_intf);
 544         struct rt2x00_ops *ops = (struct rt2x00_ops *)id->driver_info;
 545         struct ieee80211_hw *hw;
 546         struct rt2x00_dev *rt2x00dev;
 547         int retval;
 548
 549         usb_dev = usb_get_dev(usb_dev);
 550
 551         hw = ieee80211_alloc_hw(sizeof(struct rt2x00_dev), ops->hw);
 552         if (!hw) {
 553                 ERROR_PROBE("Failed to allocate hardware.\n");
 554                 retval = -ENOMEM;
 555                 goto exit_put_device;
 556         }
 557
 558         usb_set_intfdata(usb_intf, hw);
 559
 560         rt2x00dev = hw->priv;
 561         rt2x00dev->dev = usb_intf;
 562         rt2x00dev->ops = ops;
 563         rt2x00dev->hw = hw;
 564         mutex_init(&rt2x00dev->usb_cache_mutex);
 565
 566         rt2x00dev->usb_maxpacket =
 567             usb_maxpacket(usb_dev, usb_sndbulkpipe(usb_dev, 1), 1);
 568         if (!rt2x00dev->usb_maxpacket)
 569                 rt2x00dev->usb_maxpacket = 1;
 570
 571         retval = rt2x00usb_alloc_reg(rt2x00dev);
 572         if (retval)
 573                 goto exit_free_device;
 574
 575         retval = rt2x00lib_probe_dev(rt2x00dev);
 576         if (retval)
 577                 goto exit_free_reg;
 578
 579         return 0;
 580
 581 exit_free_reg:
 582         rt2x00usb_free_reg(rt2x00dev);
 583
 584 exit_free_device:
 585         ieee80211_free_hw(hw);
 586
 587 exit_put_device:
 588         usb_put_dev(usb_dev);
 589
 590         usb_set_intfdata(usb_intf, NULL);
 591
 592         return retval;
 593 }
 594 EXPORT_SYMBOL_GPL(rt2x00usb_probe);
 595
 596 void rt2x00usb_disconnect(struct usb_interface *usb_intf)
 597 {
 598         struct ieee80211_hw *hw = usb_get_intfdata(usb_intf);
 599         struct rt2x00_dev *rt2x00dev = hw->priv;
 600
 601         /*
 602          * Free all allocated data.
 603          */
 604         rt2x00lib_remove_dev(rt2x00dev);
 605         rt2x00usb_free_reg(rt2x00dev);
 606         ieee80211_free_hw(hw);
 607
 608         /*
 609          * Free the USB device data.
 610          */
 611         usb_set_intfdata(usb_intf, NULL);
 612         usb_put_dev(interface_to_usbdev(usb_intf));
 613 }
 614 EXPORT_SYMBOL_GPL(rt2x00usb_disconnect);
 615
 616 #ifdef CONFIG_PM
 617 int rt2x00usb_suspend(struct usb_interface *usb_intf, pm_message_t state)
 618 {
 619         struct ieee80211_hw *hw = usb_get_intfdata(usb_intf);
 620         struct rt2x00_dev *rt2x00dev = hw->priv;
 621         int retval;
 622
 623         retval = rt2x00lib_suspend(rt2x00dev, state);
 624         if (retval)
 625                 return retval;
 626
 627         rt2x00usb_free_reg(rt2x00dev);
 628
 629         /*
 630          * Decrease usbdev refcount.
 631          */
 632         usb_put_dev(interface_to_usbdev(usb_intf));
 633
 634         return 0;
 635 }
 636 EXPORT_SYMBOL_GPL(rt2x00usb_suspend);
 637
 638 int rt2x00usb_resume(struct usb_interface *usb_intf)
 639 {
 640         struct ieee80211_hw *hw = usb_get_intfdata(usb_intf);
 641         struct rt2x00_dev *rt2x00dev = hw->priv;
 642         int retval;
 643
 644         usb_get_dev(interface_to_usbdev(usb_intf));
 645
 646         retval = rt2x00usb_alloc_reg(rt2x00dev);
 647         if (retval)
 648                 return retval;
 649
 650         retval = rt2x00lib_resume(rt2x00dev);
 651         if (retval)
 652                 goto exit_free_reg;
 653
 654         return 0;
 655
 656 exit_free_reg:
 657         rt2x00usb_free_reg(rt2x00dev);
 658
 659         return retval;
 660 }
 661 EXPORT_SYMBOL_GPL(rt2x00usb_resume);
 662 #endif /* CONFIG_PM */
 663
 664 /*
 665  * rt2x00usb module information.
 666  */
 667 MODULE_AUTHOR(DRV_PROJECT);
 668 MODULE_VERSION(DRV_VERSION);
 669 MODULE_DESCRIPTION("rt2x00 usb library");
 670 MODULE_LICENSE("GPL");