aboutsummaryrefslogtreecommitdiff
path: root/drivers/uwb/hwa-rc.c
blob: 158e98d08af92ccce69319fbb909304e912d5de1 (plain)
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
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
768
769
770
771
772
773
774
775
776
777
778
779
780
781
782
783
784
785
786
787
788
789
790
791
792
793
794
795
796
797
798
799
800
801
802
803
804
805
806
807
808
809
810
811
812
813
814
815
816
817
818
819
820
821
822
823
824
825
826
827
828
829
830
831
832
833
834
835
836
837
838
839
840
841
842
843
844
845
846
847
848
849
850
851
852
853
854
855
856
857
858
859
860
861
862
863
864
865
866
867
868
869
870
871
872
873
874
875
876
877
878
879
880
881
882
883
884
885
886
887
888
889
890
891
892
893
894
895
896
897
898
899
900
901
902
903
904
905
906
907
908
909
910
911
912
913
914
915
916
917
918
919
920
921
922
923
924
925
926
927
928
929
930
931
932
933
934
935
936
937
938
939
940
941
942
943
944
945
/*
 * WUSB Host Wire Adapter: Radio Control Interface (WUSB[8.6])
 * Radio Control command/event transport
 *
 * Copyright (C) 2005-2006 Intel Corporation
 * Inaky Perez-Gonzalez <inaky.perez-gonzalez@intel.com>
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public License version
 * 2 as published by the Free Software Foundation.
 *
 * 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., 51 Franklin Street, Fifth Floor, Boston, MA
 * 02110-1301, USA.
 *
 *
 * Initialize the Radio Control interface Driver.
 *
 * For each device probed, creates an 'struct hwarc' which contains
 * just the representation of the UWB Radio Controller, and the logic
 * for reading notifications and passing them to the UWB Core.
 *
 * So we initialize all of those, register the UWB Radio Controller
 * and setup the notification/event handle to pipe the notifications
 * to the UWB management Daemon.
 *
 * Command and event filtering.
 *
 * This is the driver for the Radio Control Interface described in WUSB
 * 1.0. The core UWB module assumes that all drivers are compliant to the
 * WHCI 0.95 specification. We thus create a filter that parses all
 * incoming messages from the (WUSB 1.0) device and manipulate them to
 * conform to the WHCI 0.95 specification. Similarly, outgoing messages
 * are parsed and manipulated to conform to the WUSB 1.0 compliant messages
 * that the device expects. Only a few messages are affected:
 * Affected events:
 *    UWB_RC_EVT_BEACON
 *    UWB_RC_EVT_BP_SLOT_CHANGE
 *    UWB_RC_EVT_DRP_AVAIL
 *    UWB_RC_EVT_DRP
 * Affected commands:
 *    UWB_RC_CMD_SCAN
 *    UWB_RC_CMD_SET_DRP_IE
 *
 *
 *
 */
#include <linux/init.h>
#include <linux/module.h>
#include <linux/usb.h>
#include <linux/usb/wusb.h>
#include <linux/usb/wusb-wa.h>
#include <linux/uwb.h>
#include "uwb-internal.h"
#define D_LOCAL 1
#include <linux/uwb/debug.h>

/* The device uses commands and events from the WHCI specification, although
 * reporting itself as WUSB compliant. */
#define WUSB_QUIRK_WHCI_CMD_EVT		0x01

/**
 * Descriptor for an instance of the UWB Radio Control Driver that
 * attaches to the RCI interface of the Host Wired Adapter.
 *
 * Unless there is a lock specific to the 'data members', all access
 * is protected by uwb_rc->mutex.
 *
 * The NEEP (Notification/Event EndPoint) URB (@neep_urb) writes to
 * @rd_buffer. Note there is no locking because it is perfectly (heh!)
 * serialized--probe() submits an URB, callback is called, processes
 * the data (synchronously), submits another URB, and so on. There is
 * no concurrent access to the buffer.
 */
struct hwarc {
	struct usb_device *usb_dev;
	struct usb_interface *usb_iface;
	struct uwb_rc *uwb_rc;		/* UWB host controller */
	struct urb *neep_urb;		/* Notification endpoint handling */
	struct edc neep_edc;
	void *rd_buffer;		/* NEEP read buffer */
};


/* Beacon received notification (WUSB 1.0 [8.6.3.2]) */
struct uwb_rc_evt_beacon_WUSB_0100 {
	struct uwb_rceb rceb;
	u8	bChannelNumber;
	__le16	wBPSTOffset;
	u8	bLQI;
	u8	bRSSI;
	__le16	wBeaconInfoLength;
	u8	BeaconInfo[];
} __attribute__((packed));

/**
 * Filter WUSB 1.0 BEACON RCV notification to be WHCI 0.95
 *
 * @header: the incoming event
 * @buf_size: size of buffer containing incoming event
 * @new_size: size of event after filtering completed
 *
 * The WHCI 0.95 spec has a "Beacon Type" field. This value is unknown at
 * the time we receive the beacon from WUSB so we just set it to
 * UWB_RC_BEACON_TYPE_NEIGHBOR as a default.
 * The solution below allocates memory upon receipt of every beacon from a
 * WUSB device. This will deteriorate performance. What is the right way to
 * do this?
 */
static
int hwarc_filter_evt_beacon_WUSB_0100(struct uwb_rc *rc,
				      struct uwb_rceb **header,
				      const size_t buf_size,
				      size_t *new_size)
{
	struct uwb_rc_evt_beacon_WUSB_0100 *be;
	struct uwb_rc_evt_beacon *newbe;
	size_t bytes_left, ielength;
	struct device *dev = &rc->uwb_dev.dev;

	be = container_of(*header, struct uwb_rc_evt_beacon_WUSB_0100, rceb);
	bytes_left = buf_size;
	if (bytes_left < sizeof(*be)) {
		dev_err(dev, "Beacon Received Notification: Not enough data "
			"to decode for filtering (%zu vs %zu bytes needed)\n",
			bytes_left, sizeof(*be));
		return -EINVAL;
	}
	bytes_left -= sizeof(*be);
	ielength = le16_to_cpu(be->wBeaconInfoLength);
	if (bytes_left < ielength) {
		dev_err(dev, "Beacon Received Notification: Not enough data "
			"to decode IEs (%zu vs %zu bytes needed)\n",
			bytes_left, ielength);
		return -EINVAL;
	}
	newbe = kzalloc(sizeof(*newbe) + ielength, GFP_ATOMIC);
	if (newbe == NULL)
		return -ENOMEM;
	newbe->rceb = be->rceb;
	newbe->bChannelNumber = be->bChannelNumber;
	newbe->bBeaconType = UWB_RC_BEACON_TYPE_NEIGHBOR;
	newbe->wBPSTOffset = be->wBPSTOffset;
	newbe->bLQI = be->bLQI;
	newbe->bRSSI = be->bRSSI;
	newbe->wBeaconInfoLength = be->wBeaconInfoLength;
	memcpy(newbe->BeaconInfo, be->BeaconInfo, ielength);
	*header = &newbe->rceb;
	*new_size = sizeof(*newbe) + ielength;
	return 1;  /* calling function will free memory */
}


/* DRP Availability change notification (WUSB 1.0 [8.6.3.8]) */
struct uwb_rc_evt_drp_avail_WUSB_0100 {
	struct uwb_rceb rceb;
	__le16 wIELength;
	u8 IEData[];
} __attribute__((packed));

/**
 * Filter WUSB 1.0 DRP AVAILABILITY CHANGE notification to be WHCI 0.95
 *
 * @header: the incoming event
 * @buf_size: size of buffer containing incoming event
 * @new_size: size of event after filtering completed
 */
static
int hwarc_filter_evt_drp_avail_WUSB_0100(struct uwb_rc *rc,
					 struct uwb_rceb **header,
					 const size_t buf_size,
					 size_t *new_size)
{
	struct uwb_rc_evt_drp_avail_WUSB_0100 *da;
	struct uwb_rc_evt_drp_avail *newda;
	struct uwb_ie_hdr *ie_hdr;
	size_t bytes_left, ielength;
	struct device *dev = &rc->uwb_dev.dev;


	da = container_of(*header, struct uwb_rc_evt_drp_avail_WUSB_0100, rceb);
	bytes_left = buf_size;
	if (bytes_left < sizeof(*da)) {
		dev_err(dev, "Not enough data to decode DRP Avail "
			"Notification for filtering. Expected %zu, "
			"received %zu.\n", (size_t)sizeof(*da), bytes_left);
		return -EINVAL;
	}
	bytes_left -= sizeof(*da);
	ielength = le16_to_cpu(da->wIELength);
	if (bytes_left < ielength) {
		dev_err(dev, "DRP Avail Notification filter: IE length "
			"[%zu bytes] does not match actual length "
			"[%zu bytes].\n", ielength, bytes_left);
		return -EINVAL;
	}
	if (ielength < sizeof(*ie_hdr)) {
		dev_err(dev, "DRP Avail Notification filter: Not enough "
			"data to decode IE [%zu bytes, %zu needed]\n",
			ielength, sizeof(*ie_hdr));
		return -EINVAL;
	}
	ie_hdr = (void *) da->IEData;
	if (ie_hdr->length > 32) {
		dev_err(dev, "DRP Availability Change event has unexpected "
			"length for filtering. Expected < 32 bytes, "
			"got %zu bytes.\n", (size_t)ie_hdr->length);
		return -EINVAL;
	}
	newda = kzalloc(sizeof(*newda), GFP_ATOMIC);
	if (newda == NULL)
		return -ENOMEM;
	newda->rceb = da->rceb;
	memcpy(newda->bmp, (u8 *) ie_hdr + sizeof(*ie_hdr), ie_hdr->length);
	*header = &newda->rceb;
	*new_size = sizeof(*newda);
	return 1; /* calling function will free memory */
}


/* DRP notification (WUSB 1.0 [8.6.3.9]) */
struct uwb_rc_evt_drp_WUSB_0100 {
	struct uwb_rceb rceb;
	struct uwb_dev_addr wSrcAddr;
	u8 bExplicit;
	__le16 wIELength;
	u8 IEData[];
} __attribute__((packed));

/**
 * Filter WUSB 1.0 DRP Notification to be WHCI 0.95
 *
 * @header: the incoming event
 * @buf_size: size of buffer containing incoming event
 * @new_size: size of event after filtering completed
 *
 * It is hard to manage DRP reservations without having a Reason code.
 * Unfortunately there is none in the WUSB spec. We just set the default to
 * DRP IE RECEIVED.
 * We do not currently use the bBeaconSlotNumber value, so we set this to
 * zero for now.
 */
static
int hwarc_filter_evt_drp_WUSB_0100(struct uwb_rc *rc,
				   struct uwb_rceb **header,
				   const size_t buf_size,
				   size_t *new_size)
{
	struct uwb_rc_evt_drp_WUSB_0100 *drpev;
	struct uwb_rc_evt_drp *newdrpev;
	size_t bytes_left, ielength;
	struct device *dev = &rc->uwb_dev.dev;

	drpev = container_of(*header, struct uwb_rc_evt_drp_WUSB_0100, rceb);
	bytes_left = buf_size;
	if (bytes_left < sizeof(*drpev)) {
		dev_err(dev, "Not enough data to decode DRP Notification "
			"for filtering. Expected %zu, received %zu.\n",
			(size_t)sizeof(*drpev), bytes_left);
		return -EINVAL;
	}
	ielength = le16_to_cpu(drpev->wIELength);
	bytes_left -= sizeof(*drpev);
	if (bytes_left < ielength) {
		dev_err(dev, "DRP Notification filter: header length [%zu "
			"bytes] does not match actual length [%zu "
			"bytes].\n", ielength, bytes_left);
		return -EINVAL;
	}
	newdrpev = kzalloc(sizeof(*newdrpev) + ielength, GFP_ATOMIC);
	if (newdrpev == NULL)
		return -ENOMEM;
	newdrpev->rceb = drpev->rceb;
	newdrpev->src_addr = drpev->wSrcAddr;
	newdrpev->reason = UWB_DRP_NOTIF_DRP_IE_RCVD;
	newdrpev->beacon_slot_number = 0;
	newdrpev->ie_length = drpev->wIELength;
	memcpy(newdrpev->ie_data, drpev->IEData, ielength);
	*header = &newdrpev->rceb;
	*new_size = sizeof(*newdrpev) + ielength;
	return 1; /* calling function will free memory */
}


/* Scan Command (WUSB 1.0 [8.6.2.5]) */
struct uwb_rc_cmd_scan_WUSB_0100 {
	struct uwb_rccb rccb;
	u8 bChannelNumber;
	u8 bScanState;
} __attribute__((packed));

/**
 * Filter WHCI 0.95 SCAN command to be WUSB 1.0 SCAN command
 *
 * @header:   command sent to device (compliant to WHCI 0.95)
 * @size:     size of command sent to device
 *
 * We only reduce the size by two bytes because the WUSB 1.0 scan command
 * does not have the last field (wStarttime). Also, make sure we don't send
 * the device an unexpected scan type.
 */
static
int hwarc_filter_cmd_scan_WUSB_0100(struct uwb_rc *rc,
				    struct uwb_rccb **header,
				    size_t *size)
{
	struct uwb_rc_cmd_scan *sc;

	sc = container_of(*header, struct uwb_rc_cmd_scan, rccb);

	if (sc->bScanState == UWB_SCAN_ONLY_STARTTIME)
		sc->bScanState = UWB_SCAN_ONLY;
	/* Don't send the last two bytes. */
	*size -= 2;
	return 0;
}


/* SET DRP IE command (WUSB 1.0 [8.6.2.7]) */
struct uwb_rc_cmd_set_drp_ie_WUSB_0100 {
	struct uwb_rccb rccb;
	u8 bExplicit;
	__le16 wIELength;
	struct uwb_ie_drp IEData[];
} __attribute__((packed));

/**
 * Filter WHCI 0.95 SET DRP IE command to be WUSB 1.0 SET DRP IE command
 *
 * @header:   command sent to device (compliant to WHCI 0.95)
 * @size:     size of command sent to device
 *
 * WUSB has an extra bExplicit field - we assume always explicit
 * negotiation so this field is set. The command expected by the device is
 * thus larger than the one prepared by the driver so we need to
 * reallocate memory to accommodate this.
 * We trust the driver to send us the correct data so no checking is done
 * on incoming data - evn though it is variable length.
 */
static
int hwarc_filter_cmd_set_drp_ie_WUSB_0100(struct uwb_rc *rc,
					  struct uwb_rccb **header,
					  size_t *size)
{
	struct uwb_rc_cmd_set_drp_ie *orgcmd;
	struct uwb_rc_cmd_set_drp_ie_WUSB_0100 *cmd;
	size_t ielength;

	orgcmd = container_of(*header, struct uwb_rc_cmd_set_drp_ie, rccb);
	ielength = le16_to_cpu(orgcmd->wIELength);
	cmd = kzalloc(sizeof(*cmd) + ielength, GFP_KERNEL);
	if (cmd == NULL)
		return -ENOMEM;
	cmd->rccb = orgcmd->rccb;
	cmd->bExplicit = 0;
	cmd->wIELength = orgcmd->wIELength;
	memcpy(cmd->IEData, orgcmd->IEData, ielength);
	*header = &cmd->rccb;
	*size = sizeof(*cmd) + ielength;
	return 1; /* calling function will free memory */
}


/**
 * Filter data from WHCI driver to WUSB device
 *
 * @header: WHCI 0.95 compliant command from driver
 * @size:   length of command
 *
 * The routine managing commands to the device (uwb_rc_cmd()) will call the
 * filtering function pointer (if it exists) before it passes any data to
 * the device. At this time the command has been formatted according to
 * WHCI 0.95 and is ready to be sent to the device.
 *
 * The filter function will be provided with the current command and its
 * length. The function will manipulate the command if necessary and
 * potentially reallocate memory for a command that needed more memory that
 * the given command. If new memory was created the function will return 1
 * to indicate to the calling function that the memory need to be freed
 * when not needed any more. The size will contain the new length of the
 * command.
 * If memory has not been allocated we rely on the original mechanisms to
 * free the memory of the command - even when we reduce the value of size.
 */
static
int hwarc_filter_cmd_WUSB_0100(struct uwb_rc *rc, struct uwb_rccb **header,
			       size_t *size)
{
	int result;
	struct uwb_rccb *rccb = *header;
	int cmd = le16_to_cpu(rccb->wCommand);
	switch (cmd) {
	case UWB_RC_CMD_SCAN:
		result = hwarc_filter_cmd_scan_WUSB_0100(rc, header, size);
		break;
	case UWB_RC_CMD_SET_DRP_IE:
		result = hwarc_filter_cmd_set_drp_ie_WUSB_0100(rc, header, size);
		break;
	default:
		result = -ENOANO;
		break;
	}
	return result;
}


/**
 * Filter data from WHCI driver to WUSB device
 *
 * @header: WHCI 0.95 compliant command from driver
 * @size:   length of command
 *
 * Filter commands based on which protocol the device supports. The WUSB
 * errata should be the same as WHCI 0.95 so we do not filter that here -
 * only WUSB 1.0.
 */
static
int hwarc_filter_cmd(struct uwb_rc *rc, struct uwb_rccb **header,
		     size_t *size)
{
	int result = -ENOANO;
	if (rc->version == 0x0100)
		result = hwarc_filter_cmd_WUSB_0100(rc, header, size);
	return result;
}


/**
 * Compute return value as sum of incoming value and value at given offset
 *
 * @rceb:      event for which we compute the size, it contains a variable
 *	       length field.
 * @core_size: size of the "non variable" part of the event
 * @offset:    place in event where the length of the variable part is stored
 * @buf_size: total length of buffer in which event arrived - we need to make
 *	       sure we read the offset in memory that is still part of the event
 */
static
ssize_t hwarc_get_event_size(struct uwb_rc *rc, const struct uwb_rceb *rceb,
			     size_t core_size, size_t offset,
			     const size_t buf_size)
{
	ssize_t size = -ENOSPC;
	const void *ptr = rceb;
	size_t type_size = sizeof(__le16);
	struct device *dev = &rc->uwb_dev.dev;

	if (offset + type_size >= buf_size) {
		dev_err(dev, "Not enough data to read extra size of event "
			"0x%02x/%04x/%02x, only got %zu bytes.\n",
			rceb->bEventType, le16_to_cpu(rceb->wEvent),
			rceb->bEventContext, buf_size);
		goto out;
	}
	ptr += offset;
	size = core_size + le16_to_cpu(*(__le16 *)ptr);
out:
	return size;
}


/* Beacon slot change notification (WUSB 1.0 [8.6.3.5]) */
struct uwb_rc_evt_bp_slot_change_WUSB_0100 {
	struct uwb_rceb rceb;
	u8 bSlotNumber;
} __attribute__((packed));


/**
 * Filter data from WUSB device to WHCI driver
 *
 * @header:	 incoming event
 * @buf_size:	 size of buffer in which event arrived
 * @_event_size: actual size of event in the buffer
 * @new_size:	 size of event after filtered
 *
 * We don't know how the buffer is constructed - there may be more than one
 * event in it so buffer length does not determine event length. We first
 * determine the expected size of the incoming event. This value is passed
 * back only if the actual filtering succeeded (so we know the computed
 * expected size is correct). This value will be zero if
 * the event did not need any filtering.
 *
 * WHCI interprets the BP Slot Change event's data differently than
 * WUSB. The event sizes are exactly the same. The data field
 * indicates the new beacon slot in which a RC is transmitting its
 * beacon. The maximum value of this is 96 (wMacBPLength ECMA-368
 * 17.16 (Table 117)). We thus know that the WUSB value will not set
 * the bit bNoSlot, so we don't really do anything (placeholder).
 */
static
int hwarc_filter_event_WUSB_0100(struct uwb_rc *rc, struct uwb_rceb **header,
				 const size_t buf_size, size_t *_real_size,
				 size_t *_new_size)
{
	int result = -ENOANO;
	struct uwb_rceb *rceb = *header;
	int event = le16_to_cpu(rceb->wEvent);
	size_t event_size;
	size_t core_size, offset;

	if (rceb->bEventType != UWB_RC_CET_GENERAL)
		goto out;
	switch (event) {
	case UWB_RC_EVT_BEACON:
		core_size = sizeof(struct uwb_rc_evt_beacon_WUSB_0100);
		offset = offsetof(struct uwb_rc_evt_beacon_WUSB_0100,
				  wBeaconInfoLength);
		event_size = hwarc_get_event_size(rc, rceb, core_size,
						  offset, buf_size);
		if (event_size < 0)
			goto out;
		*_real_size = event_size;
		result = hwarc_filter_evt_beacon_WUSB_0100(rc, header,
							   buf_size, _new_size);
		break;
	case UWB_RC_EVT_BP_SLOT_CHANGE:
		*_new_size = *_real_size =
			sizeof(struct uwb_rc_evt_bp_slot_change_WUSB_0100);
		result = 0;
		break;

	case UWB_RC_EVT_DRP_AVAIL:
		core_size = sizeof(struct uwb_rc_evt_drp_avail_WUSB_0100);
		offset = offsetof(struct uwb_rc_evt_drp_avail_WUSB_0100,
				  wIELength);
		event_size = hwarc_get_event_size(rc, rceb, core_size,
						  offset, buf_size);
		if (event_size < 0)
			goto out;
		*_real_size = event_size;
		result = hwarc_filter_evt_drp_avail_WUSB_0100(
			rc, header, buf_size, _new_size);
		break;

	case UWB_RC_EVT_DRP:
		core_size = sizeof(struct uwb_rc_evt_drp_WUSB_0100);
		offset = offsetof(struct uwb_rc_evt_drp_WUSB_0100, wIELength);
		event_size = hwarc_get_event_size(rc, rceb, core_size,
						  offset, buf_size);
		if (event_size < 0)
			goto out;
		*_real_size = event_size;
		result = hwarc_filter_evt_drp_WUSB_0100(rc, header,
							buf_size, _new_size);
		break;

	default:
		break;
	}
out:
	return result;
}

/**
 * Filter data from WUSB device to WHCI driver
 *
 * @header:	 incoming event
 * @buf_size:	 size of buffer in which event arrived
 * @_event_size: actual size of event in the buffer
 * @_new_size:	 size of event after filtered
 *
 * Filter events based on which protocol the device supports. The WUSB
 * errata should be the same as WHCI 0.95 so we do not filter that here -
 * only WUSB 1.0.
 *
 * If we don't handle it, we return -ENOANO (why the weird error code?
 * well, so if I get it, I can pinpoint in the code that raised
 * it...after all, not too many places use the higher error codes).
 */
static
int hwarc_filter_event(struct uwb_rc *rc, struct uwb_rceb **header,
		       const size_t buf_size, size_t *_real_size,
		       size_t *_new_size)
{
	int result = -ENOANO;
	if (rc->version == 0x0100)
		result =  hwarc_filter_event_WUSB_0100(
			rc, header, buf_size, _real_size, _new_size);
	return result;
}


/**
 * Execute an UWB RC command on HWA
 *
 * @rc:	      Instance of a Radio Controller that is a HWA
 * @cmd:      Buffer containing the RCCB and payload to execute
 * @cmd_size: Size of the command buffer.
 *
 * NOTE: rc's mutex has to be locked
 */
static
int hwarc_cmd(struct uwb_rc *uwb_rc, const struct uwb_rccb *cmd, size_t cmd_size)
{
	struct hwarc *hwarc = uwb_rc->priv;
	return usb_control_msg(
		hwarc->usb_dev, usb_sndctrlpipe(hwarc->usb_dev, 0),
		WA_EXEC_RC_CMD, USB_DIR_OUT | USB_TYPE_CLASS | USB_RECIP_INTERFACE,
		0, hwarc->usb_iface->cur_altsetting->desc.bInterfaceNumber,
		(void *) cmd, cmd_size, 100 /* FIXME: this is totally arbitrary */);
}

static
int hwarc_reset(struct uwb_rc *uwb_rc)
{
	struct hwarc *hwarc = uwb_rc->priv;
	return usb_reset_device(hwarc->usb_dev);
}

/**
 * Callback for the notification and event endpoint
 *
 * Check's that everything is fine and then passes the read data to
 * the notification/event handling mechanism (neh).
 */
static
void hwarc_neep_cb(struct urb *urb)
{
	struct hwarc *hwarc = urb->context;
	struct usb_interface *usb_iface = hwarc->usb_iface;
	struct device *dev = &usb_iface->dev;
	int result;

	switch (result = urb->status) {
	case 0:
		d_printf(3, dev, "NEEP: receive stat %d, %zu bytes\n",
			 urb->status, (size_t)urb->actual_length);
		uwb_rc_neh_grok(hwarc->uwb_rc, urb->transfer_buffer,
				urb->actual_length);
		break;
	case -ECONNRESET:	/* Not an error, but a controlled situation; */
	case -ENOENT:		/* (we killed the URB)...so, no broadcast */
		d_printf(2, dev, "NEEP: URB reset/noent %d\n", urb->status);
		goto out;
	case -ESHUTDOWN:	/* going away! */
		d_printf(2, dev, "NEEP: URB down %d\n", urb->status);
		goto out;
	default:		/* On general errors, retry unless it gets ugly */
		if (edc_inc(&hwarc->neep_edc, EDC_MAX_ERRORS,
			    EDC_ERROR_TIMEFRAME))
			goto error_exceeded;
		dev_err(dev, "NEEP: URB error %d\n", urb->status);
	}
	result = usb_submit_urb(urb, GFP_ATOMIC);
	d_printf(3, dev, "NEEP: submit %d\n", result);
	if (result < 0) {
		dev_err(dev, "NEEP: Can't resubmit URB (%d) resetting device\n",
			result);
		goto error;
	}
out:
	return;

error_exceeded:
	dev_err(dev, "NEEP: URB max acceptable errors "
		"exceeded, resetting device\n");
error:
	uwb_rc_neh_error(hwarc->uwb_rc, result);
	uwb_rc_reset_all(hwarc->uwb_rc);
	return;
}

static void hwarc_init(struct hwarc *hwarc)
{
	edc_init(&hwarc->neep_edc);
}

/**
 * Initialize the notification/event endpoint stuff
 *
 * Note this is effectively a parallel thread; it knows that
 * hwarc->uwb_rc always exists because the existence of a 'hwarc'
 * means that there is a reverence on the hwarc->uwb_rc (see
 * _probe()), and thus _neep_cb() can execute safely.
 */
static int hwarc_neep_init(struct uwb_rc *rc)
{
	struct hwarc *hwarc = rc->priv;
	struct usb_interface *iface = hwarc->usb_iface;
	struct usb_device *usb_dev = interface_to_usbdev(iface);
	struct device *dev = &iface->dev;
	int result;
	struct usb_endpoint_descriptor *epd;

	epd = &iface->cur_altsetting->endpoint[0].desc;
	hwarc->rd_buffer = (void *) __get_free_page(GFP_KERNEL);
	if (hwarc->rd_buffer == NULL) {
		dev_err(dev, "Unable to allocate notification's read buffer\n");
		goto error_rd_buffer;
	}
	hwarc->neep_urb = usb_alloc_urb(0, GFP_KERNEL);
	if (hwarc->neep_urb == NULL) {
		dev_err(dev, "Unable to allocate notification URB\n");
		goto error_urb_alloc;
	}
	usb_fill_int_urb(hwarc->neep_urb, usb_dev,
			 usb_rcvintpipe(usb_dev, epd->bEndpointAddress),
			 hwarc->rd_buffer, PAGE_SIZE,
			 hwarc_neep_cb, hwarc, epd->bInterval);
	result = usb_submit_urb(hwarc->neep_urb, GFP_ATOMIC);
	if (result < 0) {
		dev_err(dev, "Cannot submit notification URB: %d\n", result);
		goto error_neep_submit;
	}
	return 0;

error_neep_submit:
	usb_free_urb(hwarc->neep_urb);
error_urb_alloc:
	free_page((unsigned long)hwarc->rd_buffer);
error_rd_buffer:
	return -ENOMEM;
}


/** Clean up all the notification endpoint resources */
static void hwarc_neep_release(struct uwb_rc *rc)
{
	struct hwarc *hwarc = rc->priv;

	usb_kill_urb(hwarc->neep_urb);
	usb_free_urb(hwarc->neep_urb);
	free_page((unsigned long)hwarc->rd_buffer);
}

/**
 * Get the version from class-specific descriptor
 *
 * NOTE: this descriptor comes with the big bundled configuration
 *	 descriptor that includes the interfaces' and endpoints', so
 *	 we just look for it in the cached copy kept by the USB stack.
 *
 * NOTE2: We convert LE fields to CPU order.
 */
static int hwarc_get_version(struct uwb_rc *rc)
{
	int result;

	struct hwarc *hwarc = rc->priv;
	struct uwb_rc_control_intf_class_desc *descr;
	struct device *dev = &rc->uwb_dev.dev;
	struct usb_device *usb_dev = hwarc->usb_dev;
	char *itr;
	struct usb_descriptor_header *hdr;
	size_t itr_size, actconfig_idx;
	u16 version;

	actconfig_idx = (usb_dev->actconfig - usb_dev->config) /
		sizeof(usb_dev->config[0]);
	itr = usb_dev->rawdescriptors[actconfig_idx];
	itr_size = le16_to_cpu(usb_dev->actconfig->desc.wTotalLength);
	while (itr_size >= sizeof(*hdr)) {
		hdr = (struct usb_descriptor_header *) itr;
		d_printf(3, dev, "Extra device descriptor: "
			 "type %02x/%u bytes @ %zu (%zu left)\n",
			 hdr->bDescriptorType, hdr->bLength,
			 (itr - usb_dev->rawdescriptors[actconfig_idx]),
			 itr_size);
		if (hdr->bDescriptorType == USB_DT_CS_RADIO_CONTROL)
			goto found;
		itr += hdr->bLength;
		itr_size -= hdr->bLength;
	}
	dev_err(dev, "cannot find Radio Control Interface Class descriptor\n");
	return -ENODEV;

found:
	result = -EINVAL;
	if (hdr->bLength > itr_size) {	/* is it available? */
		dev_err(dev, "incomplete Radio Control Interface Class "
			"descriptor (%zu bytes left, %u needed)\n",
			itr_size, hdr->bLength);
		goto error;
	}
	if (hdr->bLength < sizeof(*descr)) {
		dev_err(dev, "short Radio Control Interface Class "
			"descriptor\n");
		goto error;
	}
	descr = (struct uwb_rc_control_intf_class_desc *) hdr;
	/* Make LE fields CPU order */
	version = __le16_to_cpu(descr->bcdRCIVersion);
	if (version != 0x0100) {
		dev_err(dev, "Device reports protocol version 0x%04x. We "
			"do not support that. \n", version);
		result = -EINVAL;
		goto error;
	}
	rc->version = version;
	d_printf(3, dev, "Device supports WUSB protocol version 0x%04x \n",
		 rc->version);
	result = 0;
error:
	return result;
}

/*
 * By creating a 'uwb_rc', we have a reference on it -- that reference
 * is the one we drop when we disconnect.
 *
 * No need to switch altsettings; according to WUSB1.0[8.6.1.1], there
 * is only one altsetting allowed.
 */
static int hwarc_probe(struct usb_interface *iface,
		       const struct usb_device_id *id)
{
	int result;
	struct uwb_rc *uwb_rc;
	struct hwarc *hwarc;
	struct device *dev = &iface->dev;

	result = -ENOMEM;
	uwb_rc = uwb_rc_alloc();
	if (uwb_rc == NULL) {
		dev_err(dev, "unable to allocate RC instance\n");
		goto error_rc_alloc;
	}
	hwarc = kzalloc(sizeof(*hwarc), GFP_KERNEL);
	if (hwarc == NULL) {
		dev_err(dev, "unable to allocate HWA RC instance\n");
		goto error_alloc;
	}
	hwarc_init(hwarc);
	hwarc->usb_dev = usb_get_dev(interface_to_usbdev(iface));
	hwarc->usb_iface = usb_get_intf(iface);
	hwarc->uwb_rc = uwb_rc;

	uwb_rc->owner = THIS_MODULE;
	uwb_rc->start = hwarc_neep_init;
	uwb_rc->stop  = hwarc_neep_release;
	uwb_rc->cmd   = hwarc_cmd;
	uwb_rc->reset = hwarc_reset;
	if (id->driver_info & WUSB_QUIRK_WHCI_CMD_EVT) {
		uwb_rc->filter_cmd   = NULL;
		uwb_rc->filter_event = NULL;
	} else {
		uwb_rc->filter_cmd   = hwarc_filter_cmd;
		uwb_rc->filter_event = hwarc_filter_event;
	}

	result = uwb_rc_add(uwb_rc, dev, hwarc);
	if (result < 0)
		goto error_rc_add;
	result = hwarc_get_version(uwb_rc);
	if (result < 0) {
		dev_err(dev, "cannot retrieve version of RC \n");
		goto error_get_version;
	}
	usb_set_intfdata(iface, hwarc);
	return 0;

error_get_version:
	uwb_rc_rm(uwb_rc);
error_rc_add:
	usb_put_intf(iface);
	usb_put_dev(hwarc->usb_dev);
error_alloc:
	uwb_rc_put(uwb_rc);
error_rc_alloc:
	return result;
}

static void hwarc_disconnect(struct usb_interface *iface)
{
	struct hwarc *hwarc = usb_get_intfdata(iface);
	struct uwb_rc *uwb_rc = hwarc->uwb_rc;

	usb_set_intfdata(hwarc->usb_iface, NULL);
	uwb_rc_rm(uwb_rc);
	usb_put_intf(hwarc->usb_iface);
	usb_put_dev(hwarc->usb_dev);
	d_printf(1, &hwarc->usb_iface->dev, "freed hwarc %p\n", hwarc);
	kfree(hwarc);
	uwb_rc_put(uwb_rc);	/* when creating the device, refcount = 1 */
}

static int hwarc_pre_reset(struct usb_interface *iface)
{
	struct hwarc *hwarc = usb_get_intfdata(iface);
	struct uwb_rc *uwb_rc = hwarc->uwb_rc;

	uwb_rc_pre_reset(uwb_rc);
	return 0;
}

static int hwarc_post_reset(struct usb_interface *iface)
{
	struct hwarc *hwarc = usb_get_intfdata(iface);
	struct uwb_rc *uwb_rc = hwarc->uwb_rc;

	uwb_rc_post_reset(uwb_rc);
	return 0;
}

/** USB device ID's that we handle */
static struct usb_device_id hwarc_id_table[] = {
	/* D-Link DUB-1210 */
	{ USB_DEVICE_AND_INTERFACE_INFO(0x07d1, 0x3d02, 0xe0, 0x01, 0x02),
	  .driver_info = WUSB_QUIRK_WHCI_CMD_EVT },
	/* Intel i1480 (using firmware 1.3PA2-20070828) */
	{ USB_DEVICE_AND_INTERFACE_INFO(0x8086, 0x0c3b, 0xe0, 0x01, 0x02),
	  .driver_info = WUSB_QUIRK_WHCI_CMD_EVT },
	/* Generic match for the Radio Control interface */
	{ USB_INTERFACE_INFO(0xe0, 0x01, 0x02), },
	{ },
};
MODULE_DEVICE_TABLE(usb, hwarc_id_table);

static struct usb_driver hwarc_driver = {
	.name =		"hwa-rc",
	.id_table =	hwarc_id_table,
	.probe =	hwarc_probe,
	.disconnect =	hwarc_disconnect,
	.pre_reset =    hwarc_pre_reset,
	.post_reset =   hwarc_post_reset,
};

static int __init hwarc_driver_init(void)
{
	int result;
	result = usb_register(&hwarc_driver);
	if (result < 0)
		printk(KERN_ERR "HWA-RC: Cannot register USB driver: %d\n",
		       result);
	return result;

}
module_init(hwarc_driver_init);

static void __exit hwarc_driver_exit(void)
{
	usb_deregister(&hwarc_driver);
}
module_exit(hwarc_driver_exit);

MODULE_AUTHOR("Inaky Perez-Gonzalez <inaky.perez-gonzalez@intel.com>");
MODULE_DESCRIPTION("Host Wireless Adapter Radio Control Driver");
MODULE_LICENSE("GPL");