aboutsummaryrefslogtreecommitdiffstats
path: root/drivers/net/wireless/rt2x00/rt2x00usb.c
blob: f9a7f8b1741134e57e840ea01baa0bb4ace149b8 (plain) (blame)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
/*
	Copyright (C) 2004 - 2009 Ivo van Doorn <IvDoorn@gmail.com>
	<http://rt2x00.serialmonkey.com>

	This program is free software; you can redistribute it and/or modify
	it under the terms of the GNU General Public License as published by
	the Free Software Foundation; either version 2 of the License, or
	(at your option) any later version.

	This program is distributed in the hope that it will be useful,
	but WITHOUT ANY WARRANTY; without even the implied warranty of
	MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
	GNU General Public License for more details.

	You should have received a copy of the GNU General Public License
	along with this program; if not, write to the
	Free Software Foundation, Inc.,
	59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
 */

/*
	Module: rt2x00usb
	Abstract: rt2x00 generic usb device routines.
 */

#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/slab.h>
#include <linux/usb.h>
#include <linux/bug.h>

#include "rt2x00.h"
#include "rt2x00usb.h"

/*
 * Interfacing with the HW.
 */
int rt2x00usb_vendor_request(struct rt2x00_dev *rt2x00dev,
			     const u8 request, const u8 requesttype,
			     const u16 offset, const u16 value,
			     void *buffer, const u16 buffer_length,
			     const int timeout)
{
	struct usb_device *usb_dev = to_usb_device_intf(rt2x00dev->dev);
	int status;
	unsigned int i;
	unsigned int pipe =
	    (requesttype == USB_VENDOR_REQUEST_IN) ?
	    usb_rcvctrlpipe(usb_dev, 0) : usb_sndctrlpipe(usb_dev, 0);

	if (!test_bit(DEVICE_STATE_PRESENT, &rt2x00dev->flags))
		return -ENODEV;

	for (i = 0; i < REGISTER_BUSY_COUNT; i++) {
		status = usb_control_msg(usb_dev, pipe, request, requesttype,
					 value, offset, buffer, buffer_length,
					 timeout);
		if (status >= 0)
			return 0;

		/*
		 * Check for errors
		 * -ENODEV: Device has disappeared, no point continuing.
		 * All other errors: Try again.
		 */
		else if (status == -ENODEV) {
			clear_bit(DEVICE_STATE_PRESENT, &rt2x00dev->flags);
			break;
		}
	}

	ERROR(rt2x00dev,
	      "Vendor Request 0x%02x failed for offset 0x%04x with error %d.\n",
	      request, offset, status);

	return status;
}
EXPORT_SYMBOL_GPL(rt2x00usb_vendor_request);

int rt2x00usb_vendor_req_buff_lock(struct rt2x00_dev *rt2x00dev,
				   const u8 request, const u8 requesttype,
				   const u16 offset, void *buffer,
				   const u16 buffer_length, const int timeout)
{
	int status;

	BUG_ON(!mutex_is_locked(&rt2x00dev->csr_mutex));

	/*
	 * Check for Cache availability.
	 */
	if (unlikely(!rt2x00dev->csr.cache || buffer_length > CSR_CACHE_SIZE)) {
		ERROR(rt2x00dev, "CSR cache not available.\n");
		return -ENOMEM;
	}

	if (requesttype == USB_VENDOR_REQUEST_OUT)
		memcpy(rt2x00dev->csr.cache, buffer, buffer_length);

	status = rt2x00usb_vendor_request(rt2x00dev, request, requesttype,
					  offset, 0, rt2x00dev->csr.cache,
					  buffer_length, timeout);

	if (!status && requesttype == USB_VENDOR_REQUEST_IN)
		memcpy(buffer, rt2x00dev->csr.cache, buffer_length);

	return status;
}
EXPORT_SYMBOL_GPL(rt2x00usb_vendor_req_buff_lock);

int rt2x00usb_vendor_request_buff(struct rt2x00_dev *rt2x00dev,
				  const u8 request, const u8 requesttype,
				  const u16 offset, void *buffer,
				  const u16 buffer_length, const int timeout)
{
	int status;

	mutex_lock(&rt2x00dev->csr_mutex);

	status = rt2x00usb_vendor_req_buff_lock(rt2x00dev, request,
						requesttype, offset, buffer,
						buffer_length, timeout);

	mutex_unlock(&rt2x00dev->csr_mutex);

	return status;
}
EXPORT_SYMBOL_GPL(rt2x00usb_vendor_request_buff);

int rt2x00usb_vendor_request_large_buff(struct rt2x00_dev *rt2x00dev,
					const u8 request, const u8 requesttype,
					const u16 offset, const void *buffer,
					const u16 buffer_length,
					const int timeout)
{
	int status = 0;
	unsigned char *tb;
	u16 off, len, bsize;

	mutex_lock(&rt2x00dev->csr_mutex);

	tb  = (char *)buffer;
	off = offset;
	len = buffer_length;
	while (len && !status) {
		bsize = min_t(u16, CSR_CACHE_SIZE, len);
		status = rt2x00usb_vendor_req_buff_lock(rt2x00dev, request,
							requesttype, off, tb,
							bsize, timeout);

		tb  += bsize;
		len -= bsize;
		off += bsize;
	}

	mutex_unlock(&rt2x00dev->csr_mutex);

	return status;
}
EXPORT_SYMBOL_GPL(rt2x00usb_vendor_request_large_buff);

int rt2x00usb_regbusy_read(struct rt2x00_dev *rt2x00dev,
			   const unsigned int offset,
			   const struct rt2x00_field32 field,
			   u32 *reg)
{
	unsigned int i;

	if (!test_bit(DEVICE_STATE_PRESENT, &rt2x00dev->flags))
		return -ENODEV;

	for (i = 0; i < REGISTER_BUSY_COUNT; i++) {
		rt2x00usb_register_read_lock(rt2x00dev, offset, reg);
		if (!rt2x00_get_field32(*reg, field))
			return 1;
		udelay(REGISTER_BUSY_DELAY);
	}

	ERROR(rt2x00dev, "Indirect register access failed: "
	      "offset=0x%.08x, value=0x%.08x\n", offset, *reg);
	*reg = ~0;

	return 0;
}
EXPORT_SYMBOL_GPL(rt2x00usb_regbusy_read);

/*
 * TX data handlers.
 */
static void rt2x00usb_interrupt_txdone(struct urb *urb)
{
	struct queue_entry *entry = (struct queue_entry *)urb->context;
	struct rt2x00_dev *rt2x00dev = entry->queue->rt2x00dev;
	struct txdone_entry_desc txdesc;

	if (!test_bit(DEVICE_STATE_ENABLED_RADIO, &rt2x00dev->flags) ||
	    !test_bit(ENTRY_OWNER_DEVICE_DATA, &entry->flags))
		return;

	/*
	 * Obtain the status about this packet.
	 * Note that when the status is 0 it does not mean the
	 * frame was send out correctly. It only means the frame
	 * was succesfully pushed to the hardware, we have no
	 * way to determine the transmission status right now.
	 * (Only indirectly by looking at the failed TX counters
	 * in the register).
	 */
	txdesc.flags = 0;
	if (!urb->status)
		__set_bit(TXDONE_UNKNOWN, &txdesc.flags);
	else
		__set_bit(TXDONE_FAILURE, &txdesc.flags);
	txdesc.retry = 0;

	rt2x00lib_txdone(entry, &txdesc);
}

int rt2x00usb_write_tx_data(struct queue_entry *entry)
{
	struct rt2x00_dev *rt2x00dev = entry->queue->rt2x00dev;
	struct usb_device *usb_dev = to_usb_device_intf(rt2x00dev->dev);
	struct queue_entry_priv_usb *entry_priv = entry->priv_data;
	struct skb_frame_desc *skbdesc;
	u32 length;

	/*
	 * Add the descriptor in front of the skb.
	 */
	skb_push(entry->skb, entry->queue->desc_size);
	memset(entry->skb->data, 0, entry->queue->desc_size);

	/*
	 * Fill in skb descriptor
	 */
	skbdesc = get_skb_frame_desc(entry->skb);
	skbdesc->desc = entry->skb->data;
	skbdesc->desc_len = entry->queue->desc_size;

	/*
	 * USB devices cannot blindly pass the skb->len as the
	 * length of the data to usb_fill_bulk_urb. Pass the skb
	 * to the driver to determine what the length should be.
	 */
	length = rt2x00dev->ops->lib->get_tx_data_len(entry);

	usb_fill_bulk_urb(entry_priv->urb, usb_dev,
			  usb_sndbulkpipe(usb_dev, entry->queue->usb_endpoint),
			  entry->skb->data, length,
			  rt2x00usb_interrupt_txdone, entry);

	/*
	 * Make sure the skb->data pointer points to the frame, not the
	 * descriptor.
	 */
	skb_pull(entry->skb, entry->queue->desc_size);

	return 0;
}
EXPORT_SYMBOL_GPL(rt2x00usb_write_tx_data);

static inline void rt2x00usb_kick_tx_entry(struct queue_entry *entry)
{
	struct queue_entry_priv_usb *entry_priv = entry->priv_data;

	if (test_and_clear_bit(ENTRY_DATA_PENDING, &entry->flags))
		usb_submit_urb(entry_priv->urb, GFP_ATOMIC);
}

void rt2x00usb_kick_tx_queue(struct rt2x00_dev *rt2x00dev,
			     const enum data_queue_qid qid)
{
	struct data_queue *queue = rt2x00queue_get_queue(rt2x00dev, qid);
	unsigned long irqflags;
	unsigned int index;
	unsigned int index_done;
	unsigned int i;

	/*
	 * Only protect the range we are going to loop over,
	 * if during our loop a extra entry is set to pending
	 * it should not be kicked during this run, since it
	 * is part of another TX operation.
	 */
	spin_lock_irqsave(&queue->lock, irqflags);
	index = queue->index[Q_INDEX];
	index_done = queue->index[Q_INDEX_DONE];
	spin_unlock_irqrestore(&queue->lock, irqflags);

	/*
	 * Start from the TX done pointer, this guarentees that we will
	 * send out all frames in the correct order.
	 */
	if (index_done < index) {
		for (i = index_done; i < index; i++)
			rt2x00usb_kick_tx_entry(&queue->entries[i]);
	} else {
		for (i = index_done; i < queue->limit; i++)
			rt2x00usb_kick_tx_entry(&queue->entries[i]);

		for (i = 0; i < index; i++)
			rt2x00usb_kick_tx_entry(&queue->entries[i]);
	}
}
EXPORT_SYMBOL_GPL(rt2x00usb_kick_tx_queue);

void rt2x00usb_kill_tx_queue(struct rt2x00_dev *rt2x00dev,
			     const enum data_queue_qid qid)
{
	struct data_queue *queue = rt2x00queue_get_queue(rt2x00dev, qid);
	struct queue_entry_priv_usb *entry_priv;
	struct queue_entry_priv_usb_bcn *bcn_priv;
	unsigned int i;
	bool kill_guard;

	/*
	 * When killing the beacon queue, we must also kill
	 * the beacon guard byte.
	 */
	kill_guard =
	    (qid == QID_BEACON) &&
	    (test_bit(DRIVER_REQUIRE_BEACON_GUARD, &rt2x00dev->flags));

	/*
	 * Cancel all entries.
	 */
	for (i = 0; i < queue->limit; i++) {
		entry_priv = queue->entries[i].priv_data;
		usb_kill_urb(entry_priv->urb);

		/*
		 * Kill guardian urb (if required by driver).
		 */
		if (kill_guard) {
			bcn_priv = queue->entries[i].priv_data;
			usb_kill_urb(bcn_priv->guardian_urb);
		}
	}
}
EXPORT_SYMBOL_GPL(rt2x00usb_kill_tx_queue);

/*
 * RX data handlers.
 */
static void rt2x00usb_interrupt_rxdone(struct urb *urb)
{
	struct queue_entry *entry = (struct queue_entry *)urb->context;
	struct rt2x00_dev *rt2x00dev = entry->queue->rt2x00dev;
	struct skb_frame_desc *skbdesc = get_skb_frame_desc(entry->skb);
	u8 rxd[32];

	if (!test_bit(DEVICE_STATE_ENABLED_RADIO, &rt2x00dev->flags) ||
	    !test_bit(ENTRY_OWNER_DEVICE_DATA, &entry->flags))
		return;

	/*
	 * Check if the received data is simply too small
	 * to be actually valid, or if the urb is signaling
	 * a problem.
	 */
	if (urb->actual_length < entry->queue->desc_size || urb->status) {
		set_bit(ENTRY_OWNER_DEVICE_DATA, &entry->flags);
		usb_submit_urb(urb, GFP_ATOMIC);
		return;
	}

	/*
	 * Fill in desc fields of the skb descriptor
	 */
	skbdesc->desc = rxd;
	skbdesc->desc_len = entry->queue->desc_size;

	/*
	 * Send the frame to rt2x00lib for further processing.
	 */
	rt2x00lib_rxdone(rt2x00dev, entry);
}

/*
 * Radio handlers
 */
void rt2x00usb_disable_radio(struct rt2x00_dev *rt2x00dev)
{
	rt2x00usb_vendor_request_sw(rt2x00dev, USB_RX_CONTROL, 0, 0,
				    REGISTER_TIMEOUT);

	/*
	 * The USB version of kill_tx_queue also works
	 * on the RX queue.
	 */
	rt2x00dev->ops->lib->kill_tx_queue(rt2x00dev, QID_RX);
}
EXPORT_SYMBOL_GPL(rt2x00usb_disable_radio);

/*
 * Device initialization handlers.
 */
void rt2x00usb_clear_entry(struct queue_entry *entry)
{
	struct usb_device *usb_dev =
	    to_usb_device_intf(entry->queue->rt2x00dev->dev);
	struct queue_entry_priv_usb *entry_priv = entry->priv_data;
	int pipe;

	if (entry->queue->qid == QID_RX) {
		pipe = usb_rcvbulkpipe(usb_dev, entry->queue->usb_endpoint);
		usb_fill_bulk_urb(entry_priv->urb, usb_dev, pipe,
				entry->skb->data, entry->skb->len,
				rt2x00usb_interrupt_rxdone, entry);

		set_bit(ENTRY_OWNER_DEVICE_DATA, &entry->flags);
		usb_submit_urb(entry_priv->urb, GFP_ATOMIC);
	} else {
		entry->flags = 0;
	}
}
EXPORT_SYMBOL_GPL(rt2x00usb_clear_entry);

static void rt2x00usb_assign_endpoint(struct data_queue *queue,
				      struct usb_endpoint_descriptor *ep_desc)
{
	struct usb_device *usb_dev = to_usb_device_intf(queue->rt2x00dev->dev);
	int pipe;

	queue->usb_endpoint = usb_endpoint_num(ep_desc);

	if (queue->qid == QID_RX) {
		pipe = usb_rcvbulkpipe(usb_dev, queue->usb_endpoint);
		queue->usb_maxpacket = usb_maxpacket(usb_dev, pipe, 0);
	} else {
		pipe = usb_sndbulkpipe(usb_dev, queue->usb_endpoint);
		queue->usb_maxpacket = usb_maxpacket(usb_dev, pipe, 1);
	}

	if (!queue->usb_maxpacket)
		queue->usb_maxpacket = 1;
}

static int rt2x00usb_find_endpoints(struct rt2x00_dev *rt2x00dev)
{
	struct usb_interface *intf = to_usb_interface(rt2x00dev->dev);
	struct usb_host_interface *intf_desc = intf->cur_altsetting;
	struct usb_endpoint_descriptor *ep_desc;
	struct data_queue *queue = rt2x00dev->tx;
	struct usb_endpoint_descriptor *tx_ep_desc = NULL;
	unsigned int i;

	/*
	 * Walk through all available endpoints to search for "bulk in"
	 * and "bulk out" endpoints. When we find such endpoints collect
	 * the information we need from the descriptor and assign it
	 * to the queue.
	 */
	for (i = 0; i < intf_desc->desc.bNumEndpoints; i++) {
		ep_desc = &intf_desc->endpoint[i].desc;

		if (usb_endpoint_is_bulk_in(ep_desc)) {
			rt2x00usb_assign_endpoint(rt2x00dev->rx, ep_desc);
		} else if (usb_endpoint_is_bulk_out(ep_desc) &&
			   (queue != queue_end(rt2x00dev))) {
			rt2x00usb_assign_endpoint(queue, ep_desc);
			queue = queue_next(queue);

			tx_ep_desc = ep_desc;
		}
	}

	/*
	 * At least 1 endpoint for RX and 1 endpoint for TX must be available.
	 */
	if (!rt2x00dev->rx->usb_endpoint || !rt2x00dev->tx->usb_endpoint) {
		ERROR(rt2x00dev, "Bulk-in/Bulk-out endpoints not found\n");
		return -EPIPE;
	}

	/*
	 * It might be possible not all queues have a dedicated endpoint.
	 * Loop through all TX queues and copy the endpoint information
	 * which we have gathered from already assigned endpoints.
	 */
	txall_queue_for_each(rt2x00dev, queue) {
		if (!queue->usb_endpoint)
			rt2x00usb_assign_endpoint(queue, tx_ep_desc);
	}

	return 0;
}

static int rt2x00usb_alloc_urb(struct rt2x00_dev *rt2x00dev,
			       struct data_queue *queue)
{
	struct queue_entry_priv_usb *entry_priv;
	struct queue_entry_priv_usb_bcn *bcn_priv;
	unsigned int i;

	for (i = 0; i < queue->limit; i++) {
		entry_priv = queue->entries[i].priv_data;
		entry_priv->urb = usb_alloc_urb(0, GFP_KERNEL);
		if (!entry_priv->urb)
			return -ENOMEM;
	}

	/*
	 * If this is not the beacon queue or
	 * no guardian byte was required for the beacon,
	 * then we are done.
	 */
	if (rt2x00dev->bcn != queue ||
	    !test_bit(DRIVER_REQUIRE_BEACON_GUARD, &rt2x00dev->flags))
		return 0;

	for (i = 0; i < queue->limit; i++) {
		bcn_priv = queue->entries[i].priv_data;
		bcn_priv->guardian_urb = usb_alloc_urb(0, GFP_KERNEL);
		if (!bcn_priv->guardian_urb)
			return -ENOMEM;
	}

	return 0;
}

static void rt2x00usb_free_urb(struct rt2x00_dev *rt2x00dev,
			       struct data_queue *queue)
{
	struct queue_entry_priv_usb *entry_priv;
	struct queue_entry_priv_usb_bcn *bcn_priv;
	unsigned int i;

	if (!queue->entries)
		return;

	for (i = 0; i < queue->limit; i++) {
		entry_priv = queue->entries[i].priv_data;
		usb_kill_urb(entry_priv->urb);
		usb_free_urb(entry_priv->urb);
	}

	/*
	 * If this is not the beacon queue or
	 * no guardian byte was required for the beacon,
	 * then we are done.
	 */
	if (rt2x00dev->bcn != queue ||
	    !test_bit(DRIVER_REQUIRE_BEACON_GUARD, &rt2x00dev->flags))
		return;

	for (i = 0; i < queue->limit; i++) {
		bcn_priv = queue->entries[i].priv_data;
		usb_kill_urb(bcn_priv->guardian_urb);
		usb_free_urb(bcn_priv->guardian_urb);
	}
}

int rt2x00usb_initialize(struct rt2x00_dev *rt2x00dev)
{
	struct data_queue *queue;
	int status;

	/*
	 * Find endpoints for each queue
	 */
	status = rt2x00usb_find_endpoints(rt2x00dev);
	if (status)
		goto exit;

	/*
	 * Allocate DMA
	 */
	queue_for_each(rt2x00dev, queue) {
		status = rt2x00usb_alloc_urb(rt2x00dev, queue);
		if (status)
			goto exit;
	}

	return 0;

exit:
	rt2x00usb_uninitialize(rt2x00dev);

	return status;
}
EXPORT_SYMBOL_GPL(rt2x00usb_initialize);

void rt2x00usb_uninitialize(struct rt2x00_dev *rt2x00dev)
{
	struct data_queue *queue;

	queue_for_each(rt2x00dev, queue)
		rt2x00usb_free_urb(rt2x00dev, queue);
}
EXPORT_SYMBOL_GPL(rt2x00usb_uninitialize);

/*
 * USB driver handlers.
 */
static void rt2x00usb_free_reg(struct rt2x00_dev *rt2x00dev)
{
	kfree(rt2x00dev->rf);
	rt2x00dev->rf = NULL;

	kfree(rt2x00dev->eeprom);
	rt2x00dev->eeprom = NULL;

	kfree(rt2x00dev->csr.cache);
	rt2x00dev->csr.cache = NULL;
}

static int rt2x00usb_alloc_reg(struct rt2x00_dev *rt2x00dev)
{
	rt2x00dev->csr.cache = kzalloc(CSR_CACHE_SIZE, GFP_KERNEL);
	if (!rt2x00dev->csr.cache)
		goto exit;

	rt2x00dev->eeprom = kzalloc(rt2x00dev->ops->eeprom_size, GFP_KERNEL);
	if (!rt2x00dev->eeprom)
		goto exit;

	rt2x00dev->rf = kzalloc(rt2x00dev->ops->rf_size, GFP_KERNEL);
	if (!rt2x00dev->rf)
		goto exit;

	return 0;

exit:
	ERROR_PROBE("Failed to allocate registers.\n");

	rt2x00usb_free_reg(rt2x00dev);

	return -ENOMEM;
}

int rt2x00usb_probe(struct usb_interface *usb_intf,
		    const struct usb_device_id *id)
{
	struct usb_device *usb_dev = interface_to_usbdev(usb_intf);
	struct rt2x00_ops *ops = (struct rt2x00_ops *)id->driver_info;
	struct ieee80211_hw *hw;
	struct rt2x00_dev *rt2x00dev;
	int retval;

	usb_dev = usb_get_dev(usb_dev);

	hw = ieee80211_alloc_hw(sizeof(struct rt2x00_dev), ops->hw);
	if (!hw) {
		ERROR_PROBE("Failed to allocate hardware.\n");
		retval = -ENOMEM;
		goto exit_put_device;
	}

	usb_set_intfdata(usb_intf, hw);

	rt2x00dev = hw->priv;
	rt2x00dev->dev = &usb_intf->dev;
	rt2x00dev->ops = ops;
	rt2x00dev->hw = hw;

	rt2x00_set_chip_intf(rt2x00dev, RT2X00_CHIP_INTF_USB);

	retval = rt2x00usb_alloc_reg(rt2x00dev);
	if (retval)
		goto exit_free_device;

	retval = rt2x00lib_probe_dev(rt2x00dev);
	if (retval)
		goto exit_free_reg;

	return 0;

exit_free_reg:
	rt2x00usb_free_reg(rt2x00dev);

exit_free_device:
	ieee80211_free_hw(hw);

exit_put_device:
	usb_put_dev(usb_dev);

	usb_set_intfdata(usb_intf, NULL);

	return retval;
}
EXPORT_SYMBOL_GPL(rt2x00usb_probe);

void rt2x00usb_disconnect(struct usb_interface *usb_intf)
{
	struct ieee80211_hw *hw = usb_get_intfdata(usb_intf);
	struct rt2x00_dev *rt2x00dev = hw->priv;

	/*
	 * Free all allocated data.
	 */
	rt2x00lib_remove_dev(rt2x00dev);
	rt2x00usb_free_reg(rt2x00dev);
	ieee80211_free_hw(hw);

	/*
	 * Free the USB device data.
	 */
	usb_set_intfdata(usb_intf, NULL);
	usb_put_dev(interface_to_usbdev(usb_intf));
}
EXPORT_SYMBOL_GPL(rt2x00usb_disconnect);

#ifdef CONFIG_PM
int rt2x00usb_suspend(struct usb_interface *usb_intf, pm_message_t state)
{
	struct ieee80211_hw *hw = usb_get_intfdata(usb_intf);
	struct rt2x00_dev *rt2x00dev = hw->priv;
	int retval;

	retval = rt2x00lib_suspend(rt2x00dev, state);
	if (retval)
		return retval;

	/*
	 * Decrease usbdev refcount.
	 */
	usb_put_dev(interface_to_usbdev(usb_intf));

	return 0;
}
EXPORT_SYMBOL_GPL(rt2x00usb_suspend);

int rt2x00usb_resume(struct usb_interface *usb_intf)
{
	struct ieee80211_hw *hw = usb_get_intfdata(usb_intf);
	struct rt2x00_dev *rt2x00dev = hw->priv;

	usb_get_dev(interface_to_usbdev(usb_intf));

	return rt2x00lib_resume(rt2x00dev);
}
EXPORT_SYMBOL_GPL(rt2x00usb_resume);
#endif /* CONFIG_PM */

/*
 * rt2x00usb module information.
 */
MODULE_AUTHOR(DRV_PROJECT);
MODULE_VERSION(DRV_VERSION);
MODULE_DESCRIPTION("rt2x00 usb library");
MODULE_LICENSE("GPL");