aboutsummaryrefslogtreecommitdiffstats
path: root/drivers/media/video/uvc/uvc_v4l2.c
blob: fa150fff2c10964e0ea8c2b9deb0ac22a98a96a3 (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
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
946
947
948
949
950
951
952
953
954
955
956
957
958
959
960
961
962
963
964
965
966
967
968
969
970
971
972
973
974
975
976
977
978
979
980
981
982
983
984
985
986
987
988
989
990
991
992
993
994
995
996
997
998
999
1000
1001
1002
1003
1004
1005
1006
1007
1008
1009
1010
1011
1012
1013
1014
1015
1016
1017
1018
1019
1020
1021
1022
1023
1024
1025
1026
1027
1028
1029
1030
1031
1032
1033
1034
1035
1036
1037
1038
1039
1040
1041
1042
1043
1044
1045
1046
1047
1048
1049
1050
1051
1052
1053
1054
1055
1056
1057
1058
1059
1060
1061
1062
1063
1064
1065
1066
1067
1068
1069
1070
1071
1072
1073
1074
1075
1076
1077
1078
1079
1080
1081
1082
1083
1084
1085
1086
1087
1088
1089
1090
1091
1092
1093
1094
1095
1096
1097
1098
1099
1100
1101
1102
1103
1104
1105
1106
1107
1108
1109
/*
 *      uvc_v4l2.c  --  USB Video Class driver - V4L2 API
 *
 *      Copyright (C) 2005-2008
 *          Laurent Pinchart (laurent.pinchart@skynet.be)
 *
 *      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.
 *
 */

#include <linux/kernel.h>
#include <linux/version.h>
#include <linux/list.h>
#include <linux/module.h>
#include <linux/usb.h>
#include <linux/videodev2.h>
#include <linux/vmalloc.h>
#include <linux/mm.h>
#include <linux/wait.h>
#include <asm/atomic.h>

#include <media/v4l2-common.h>
#include <media/v4l2-ioctl.h>

#include "uvcvideo.h"

/* ------------------------------------------------------------------------
 * V4L2 interface
 */

/*
 * Mapping V4L2 controls to UVC controls can be straighforward if done well.
 * Most of the UVC controls exist in V4L2, and can be mapped directly. Some
 * must be grouped (for instance the Red Balance, Blue Balance and Do White
 * Balance V4L2 controls use the White Balance Component UVC control) or
 * otherwise translated. The approach we take here is to use a translation
 * table for the controls which can be mapped directly, and handle the others
 * manually.
 */
static int uvc_v4l2_query_menu(struct uvc_video_device *video,
	struct v4l2_querymenu *query_menu)
{
	struct uvc_menu_info *menu_info;
	struct uvc_control_mapping *mapping;
	struct uvc_control *ctrl;

	ctrl = uvc_find_control(video, query_menu->id, &mapping);
	if (ctrl == NULL || mapping->v4l2_type != V4L2_CTRL_TYPE_MENU)
		return -EINVAL;

	if (query_menu->index >= mapping->menu_count)
		return -EINVAL;

	menu_info = &mapping->menu_info[query_menu->index];
	strncpy(query_menu->name, menu_info->name, 32);
	return 0;
}

/*
 * Find the frame interval closest to the requested frame interval for the
 * given frame format and size. This should be done by the device as part of
 * the Video Probe and Commit negotiation, but some hardware don't implement
 * that feature.
 */
static __u32 uvc_try_frame_interval(struct uvc_frame *frame, __u32 interval)
{
	unsigned int i;

	if (frame->bFrameIntervalType) {
		__u32 best = -1, dist;

		for (i = 0; i < frame->bFrameIntervalType; ++i) {
			dist = interval > frame->dwFrameInterval[i]
			     ? interval - frame->dwFrameInterval[i]
			     : frame->dwFrameInterval[i] - interval;

			if (dist > best)
				break;

			best = dist;
		}

		interval = frame->dwFrameInterval[i-1];
	} else {
		const __u32 min = frame->dwFrameInterval[0];
		const __u32 max = frame->dwFrameInterval[1];
		const __u32 step = frame->dwFrameInterval[2];

		interval = min + (interval - min + step/2) / step * step;
		if (interval > max)
			interval = max;
	}

	return interval;
}

static int uvc_v4l2_try_format(struct uvc_video_device *video,
	struct v4l2_format *fmt, struct uvc_streaming_control *probe,
	struct uvc_format **uvc_format, struct uvc_frame **uvc_frame)
{
	struct uvc_format *format = NULL;
	struct uvc_frame *frame = NULL;
	__u16 rw, rh;
	unsigned int d, maxd;
	unsigned int i;
	__u32 interval;
	int ret = 0;
	__u8 *fcc;

	if (fmt->type != video->streaming->type)
		return -EINVAL;

	fcc = (__u8 *)&fmt->fmt.pix.pixelformat;
	uvc_trace(UVC_TRACE_FORMAT, "Trying format 0x%08x (%c%c%c%c): %ux%u.\n",
			fmt->fmt.pix.pixelformat,
			fcc[0], fcc[1], fcc[2], fcc[3],
			fmt->fmt.pix.width, fmt->fmt.pix.height);

	/* Check if the hardware supports the requested format. */
	for (i = 0; i < video->streaming->nformats; ++i) {
		format = &video->streaming->format[i];
		if (format->fcc == fmt->fmt.pix.pixelformat)
			break;
	}

	if (format == NULL || format->fcc != fmt->fmt.pix.pixelformat) {
		uvc_trace(UVC_TRACE_FORMAT, "Unsupported format 0x%08x.\n",
				fmt->fmt.pix.pixelformat);
		return -EINVAL;
	}

	/* Find the closest image size. The distance between image sizes is
	 * the size in pixels of the non-overlapping regions between the
	 * requested size and the frame-specified size.
	 */
	rw = fmt->fmt.pix.width;
	rh = fmt->fmt.pix.height;
	maxd = (unsigned int)-1;

	for (i = 0; i < format->nframes; ++i) {
		__u16 w = format->frame[i].wWidth;
		__u16 h = format->frame[i].wHeight;

		d = min(w, rw) * min(h, rh);
		d = w*h + rw*rh - 2*d;
		if (d < maxd) {
			maxd = d;
			frame = &format->frame[i];
		}

		if (maxd == 0)
			break;
	}

	if (frame == NULL) {
		uvc_trace(UVC_TRACE_FORMAT, "Unsupported size %ux%u.\n",
				fmt->fmt.pix.width, fmt->fmt.pix.height);
		return -EINVAL;
	}

	/* Use the default frame interval. */
	interval = frame->dwDefaultFrameInterval;
	uvc_trace(UVC_TRACE_FORMAT, "Using default frame interval %u.%u us "
		"(%u.%u fps).\n", interval/10, interval%10, 10000000/interval,
		(100000000/interval)%10);

	/* Set the format index, frame index and frame interval. */
	memset(probe, 0, sizeof *probe);
	probe->bmHint = 1;	/* dwFrameInterval */
	probe->bFormatIndex = format->index;
	probe->bFrameIndex = frame->bFrameIndex;
	probe->dwFrameInterval = uvc_try_frame_interval(frame, interval);
	/* Some webcams stall the probe control set request when the
	 * dwMaxVideoFrameSize field is set to zero. The UVC specification
	 * clearly states that the field is read-only from the host, so this
	 * is a webcam bug. Set dwMaxVideoFrameSize to the value reported by
	 * the webcam to work around the problem.
	 *
	 * The workaround could probably be enabled for all webcams, so the
	 * quirk can be removed if needed. It's currently useful to detect
	 * webcam bugs and fix them before they hit the market (providing
	 * developers test their webcams with the Linux driver as well as with
	 * the Windows driver).
	 */
	if (video->dev->quirks & UVC_QUIRK_PROBE_EXTRAFIELDS)
		probe->dwMaxVideoFrameSize =
			video->streaming->ctrl.dwMaxVideoFrameSize;

	/* Probe the device */
	if ((ret = uvc_probe_video(video, probe)) < 0)
		goto done;

	fmt->fmt.pix.width = frame->wWidth;
	fmt->fmt.pix.height = frame->wHeight;
	fmt->fmt.pix.field = V4L2_FIELD_NONE;
	fmt->fmt.pix.bytesperline = format->bpp * frame->wWidth / 8;
	fmt->fmt.pix.sizeimage = probe->dwMaxVideoFrameSize;
	fmt->fmt.pix.colorspace = format->colorspace;
	fmt->fmt.pix.priv = 0;

	if (uvc_format != NULL)
		*uvc_format = format;
	if (uvc_frame != NULL)
		*uvc_frame = frame;

done:
	return ret;
}

static int uvc_v4l2_get_format(struct uvc_video_device *video,
	struct v4l2_format *fmt)
{
	struct uvc_format *format = video->streaming->cur_format;
	struct uvc_frame *frame = video->streaming->cur_frame;

	if (fmt->type != video->streaming->type)
		return -EINVAL;

	if (format == NULL || frame == NULL)
		return -EINVAL;

	fmt->fmt.pix.pixelformat = format->fcc;
	fmt->fmt.pix.width = frame->wWidth;
	fmt->fmt.pix.height = frame->wHeight;
	fmt->fmt.pix.field = V4L2_FIELD_NONE;
	fmt->fmt.pix.bytesperline = format->bpp * frame->wWidth / 8;
	fmt->fmt.pix.sizeimage = video->streaming->ctrl.dwMaxVideoFrameSize;
	fmt->fmt.pix.colorspace = format->colorspace;
	fmt->fmt.pix.priv = 0;

	return 0;
}

static int uvc_v4l2_set_format(struct uvc_video_device *video,
	struct v4l2_format *fmt)
{
	struct uvc_streaming_control probe;
	struct uvc_format *format;
	struct uvc_frame *frame;
	int ret;

	if (fmt->type != video->streaming->type)
		return -EINVAL;

	if (uvc_queue_streaming(&video->queue))
		return -EBUSY;

	ret = uvc_v4l2_try_format(video, fmt, &probe, &format, &frame);
	if (ret < 0)
		return ret;

	memcpy(&video->streaming->ctrl, &probe, sizeof probe);
	video->streaming->cur_format = format;
	video->streaming->cur_frame = frame;

	return 0;
}

static int uvc_v4l2_get_streamparm(struct uvc_video_device *video,
		struct v4l2_streamparm *parm)
{
	uint32_t numerator, denominator;

	if (parm->type != video->streaming->type)
		return -EINVAL;

	numerator = video->streaming->ctrl.dwFrameInterval;
	denominator = 10000000;
	uvc_simplify_fraction(&numerator, &denominator, 8, 333);

	memset(parm, 0, sizeof *parm);
	parm->type = video->streaming->type;

	if (video->streaming->type == V4L2_BUF_TYPE_VIDEO_CAPTURE) {
		parm->parm.capture.capability = V4L2_CAP_TIMEPERFRAME;
		parm->parm.capture.capturemode = 0;
		parm->parm.capture.timeperframe.numerator = numerator;
		parm->parm.capture.timeperframe.denominator = denominator;
		parm->parm.capture.extendedmode = 0;
		parm->parm.capture.readbuffers = 0;
	} else {
		parm->parm.output.capability = V4L2_CAP_TIMEPERFRAME;
		parm->parm.output.outputmode = 0;
		parm->parm.output.timeperframe.numerator = numerator;
		parm->parm.output.timeperframe.denominator = denominator;
	}

	return 0;
}

static int uvc_v4l2_set_streamparm(struct uvc_video_device *video,
		struct v4l2_streamparm *parm)
{
	struct uvc_frame *frame = video->streaming->cur_frame;
	struct uvc_streaming_control probe;
	struct v4l2_fract timeperframe;
	uint32_t interval;
	int ret;

	if (parm->type != video->streaming->type)
		return -EINVAL;

	if (uvc_queue_streaming(&video->queue))
		return -EBUSY;

	if (parm->type == V4L2_BUF_TYPE_VIDEO_CAPTURE)
		timeperframe = parm->parm.capture.timeperframe;
	else
		timeperframe = parm->parm.output.timeperframe;

	memcpy(&probe, &video->streaming->ctrl, sizeof probe);
	interval = uvc_fraction_to_interval(timeperframe.numerator,
		timeperframe.denominator);

	uvc_trace(UVC_TRACE_FORMAT, "Setting frame interval to %u/%u (%u).\n",
		timeperframe.numerator, timeperframe.denominator, interval);
	probe.dwFrameInterval = uvc_try_frame_interval(frame, interval);

	/* Probe the device with the new settings. */
	if ((ret = uvc_probe_video(video, &probe)) < 0)
		return ret;

	memcpy(&video->streaming->ctrl, &probe, sizeof probe);

	/* Return the actual frame period. */
	timeperframe.numerator = probe.dwFrameInterval;
	timeperframe.denominator = 10000000;
	uvc_simplify_fraction(&timeperframe.numerator,
		&timeperframe.denominator, 8, 333);

	if (parm->type == V4L2_BUF_TYPE_VIDEO_CAPTURE)
		parm->parm.capture.timeperframe = timeperframe;
	else
		parm->parm.output.timeperframe = timeperframe;

	return 0;
}

/* ------------------------------------------------------------------------
 * Privilege management
 */

/*
 * Privilege management is the multiple-open implementation basis. The current
 * implementation is completely transparent for the end-user and doesn't
 * require explicit use of the VIDIOC_G_PRIORITY and VIDIOC_S_PRIORITY ioctls.
 * Those ioctls enable finer control on the device (by making possible for a
 * user to request exclusive access to a device), but are not mature yet.
 * Switching to the V4L2 priority mechanism might be considered in the future
 * if this situation changes.
 *
 * Each open instance of a UVC device can either be in a privileged or
 * unprivileged state. Only a single instance can be in a privileged state at
 * a given time. Trying to perform an operation which requires privileges will
 * automatically acquire the required privileges if possible, or return -EBUSY
 * otherwise. Privileges are dismissed when closing the instance.
 *
 * Operations which require privileges are:
 *
 * - VIDIOC_S_INPUT
 * - VIDIOC_S_PARM
 * - VIDIOC_S_FMT
 * - VIDIOC_TRY_FMT
 * - VIDIOC_REQBUFS
 */
static int uvc_acquire_privileges(struct uvc_fh *handle)
{
	int ret = 0;

	/* Always succeed if the handle is already privileged. */
	if (handle->state == UVC_HANDLE_ACTIVE)
		return 0;

	/* Check if the device already has a privileged handle. */
	mutex_lock(&uvc_driver.open_mutex);
	if (atomic_inc_return(&handle->device->active) != 1) {
		atomic_dec(&handle->device->active);
		ret = -EBUSY;
		goto done;
	}

	handle->state = UVC_HANDLE_ACTIVE;

done:
	mutex_unlock(&uvc_driver.open_mutex);
	return ret;
}

static void uvc_dismiss_privileges(struct uvc_fh *handle)
{
	if (handle->state == UVC_HANDLE_ACTIVE)
		atomic_dec(&handle->device->active);

	handle->state = UVC_HANDLE_PASSIVE;
}

static int uvc_has_privileges(struct uvc_fh *handle)
{
	return handle->state == UVC_HANDLE_ACTIVE;
}

/* ------------------------------------------------------------------------
 * V4L2 file operations
 */

static int uvc_v4l2_open(struct file *file)
{
	struct uvc_video_device *video;
	struct uvc_fh *handle;
	int ret = 0;

	uvc_trace(UVC_TRACE_CALLS, "uvc_v4l2_open\n");
	mutex_lock(&uvc_driver.open_mutex);
	video = video_drvdata(file);

	if (video->dev->state & UVC_DEV_DISCONNECTED) {
		ret = -ENODEV;
		goto done;
	}

	ret = usb_autopm_get_interface(video->dev->intf);
	if (ret < 0)
		goto done;

	/* Create the device handle. */
	handle = kzalloc(sizeof *handle, GFP_KERNEL);
	if (handle == NULL) {
		usb_autopm_put_interface(video->dev->intf);
		ret = -ENOMEM;
		goto done;
	}

	handle->device = video;
	handle->state = UVC_HANDLE_PASSIVE;
	file->private_data = handle;

	kref_get(&video->dev->kref);

done:
	mutex_unlock(&uvc_driver.open_mutex);
	return ret;
}

static int uvc_v4l2_release(struct file *file)
{
	struct uvc_video_device *video = video_drvdata(file);
	struct uvc_fh *handle = (struct uvc_fh *)file->private_data;

	uvc_trace(UVC_TRACE_CALLS, "uvc_v4l2_release\n");

	/* Only free resources if this is a privileged handle. */
	if (uvc_has_privileges(handle)) {
		uvc_video_enable(video, 0);

		mutex_lock(&video->queue.mutex);
		if (uvc_free_buffers(&video->queue) < 0)
			uvc_printk(KERN_ERR, "uvc_v4l2_release: Unable to "
					"free buffers.\n");
		mutex_unlock(&video->queue.mutex);
	}

	/* Release the file handle. */
	uvc_dismiss_privileges(handle);
	kfree(handle);
	file->private_data = NULL;

	usb_autopm_put_interface(video->dev->intf);
	kref_put(&video->dev->kref, uvc_delete);
	return 0;
}

static long uvc_v4l2_do_ioctl(struct file *file, unsigned int cmd, void *arg)
{
	struct video_device *vdev = video_devdata(file);
	struct uvc_video_device *video = video_get_drvdata(vdev);
	struct uvc_fh *handle = (struct uvc_fh *)file->private_data;
	long ret = 0;

	switch (cmd) {
	/* Query capabilities */
	case VIDIOC_QUERYCAP:
	{
		struct v4l2_capability *cap = arg;

		memset(cap, 0, sizeof *cap);
		strncpy(cap->driver, "uvcvideo", sizeof cap->driver);
		strncpy(cap->card, vdev->name, 32);
		strncpy(cap->bus_info, video->dev->udev->bus->bus_name,
			sizeof cap->bus_info);
		cap->version = DRIVER_VERSION_NUMBER;
		if (video->streaming->type == V4L2_BUF_TYPE_VIDEO_CAPTURE)
			cap->capabilities = V4L2_CAP_VIDEO_CAPTURE
					  | V4L2_CAP_STREAMING;
		else
			cap->capabilities = V4L2_CAP_VIDEO_OUTPUT
					  | V4L2_CAP_STREAMING;
		break;
	}

	/* Get, Set & Query control */
	case VIDIOC_QUERYCTRL:
		return uvc_query_v4l2_ctrl(video, arg);

	case VIDIOC_G_CTRL:
	{
		struct v4l2_control *ctrl = arg;
		struct v4l2_ext_control xctrl;

		memset(&xctrl, 0, sizeof xctrl);
		xctrl.id = ctrl->id;

		uvc_ctrl_begin(video);
		ret = uvc_ctrl_get(video, &xctrl);
		uvc_ctrl_rollback(video);
		if (ret >= 0)
			ctrl->value = xctrl.value;
		break;
	}

	case VIDIOC_S_CTRL:
	{
		struct v4l2_control *ctrl = arg;
		struct v4l2_ext_control xctrl;

		memset(&xctrl, 0, sizeof xctrl);
		xctrl.id = ctrl->id;
		xctrl.value = ctrl->value;

		uvc_ctrl_begin(video);
		ret = uvc_ctrl_set(video, &xctrl);
		if (ret < 0) {
			uvc_ctrl_rollback(video);
			return ret;
		}
		ret = uvc_ctrl_commit(video);
		break;
	}

	case VIDIOC_QUERYMENU:
		return uvc_v4l2_query_menu(video, arg);

	case VIDIOC_G_EXT_CTRLS:
	{
		struct v4l2_ext_controls *ctrls = arg;
		struct v4l2_ext_control *ctrl = ctrls->controls;
		unsigned int i;

		uvc_ctrl_begin(video);
		for (i = 0; i < ctrls->count; ++ctrl, ++i) {
			ret = uvc_ctrl_get(video, ctrl);
			if (ret < 0) {
				uvc_ctrl_rollback(video);
				ctrls->error_idx = i;
				return ret;
			}
		}
		ctrls->error_idx = 0;
		ret = uvc_ctrl_rollback(video);
		break;
	}

	case VIDIOC_S_EXT_CTRLS:
	case VIDIOC_TRY_EXT_CTRLS:
	{
		struct v4l2_ext_controls *ctrls = arg;
		struct v4l2_ext_control *ctrl = ctrls->controls;
		unsigned int i;

		ret = uvc_ctrl_begin(video);
		if (ret < 0)
			return ret;

		for (i = 0; i < ctrls->count; ++ctrl, ++i) {
			ret = uvc_ctrl_set(video, ctrl);
			if (ret < 0) {
				uvc_ctrl_rollback(video);
				ctrls->error_idx = i;
				return ret;
			}
		}

		ctrls->error_idx = 0;

		if (cmd == VIDIOC_S_EXT_CTRLS)
			ret = uvc_ctrl_commit(video);
		else
			ret = uvc_ctrl_rollback(video);
		break;
	}

	/* Get, Set & Enum input */
	case VIDIOC_ENUMINPUT:
	{
		const struct uvc_entity *selector = video->selector;
		struct v4l2_input *input = arg;
		struct uvc_entity *iterm = NULL;
		u32 index = input->index;
		int pin = 0;

		if (selector == NULL ||
		    (video->dev->quirks & UVC_QUIRK_IGNORE_SELECTOR_UNIT)) {
			if (index != 0)
				return -EINVAL;
			iterm = list_first_entry(&video->iterms,
					struct uvc_entity, chain);
			pin = iterm->id;
		} else if (pin < selector->selector.bNrInPins) {
			pin = selector->selector.baSourceID[index];
			list_for_each_entry(iterm, video->iterms.next, chain) {
				if (iterm->id == pin)
					break;
			}
		}

		if (iterm == NULL || iterm->id != pin)
			return -EINVAL;

		memset(input, 0, sizeof *input);
		input->index = index;
		strncpy(input->name, iterm->name, sizeof input->name);
		if (UVC_ENTITY_TYPE(iterm) == ITT_CAMERA)
			input->type = V4L2_INPUT_TYPE_CAMERA;
		break;
	}

	case VIDIOC_G_INPUT:
	{
		u8 input;

		if (video->selector == NULL ||
		    (video->dev->quirks & UVC_QUIRK_IGNORE_SELECTOR_UNIT)) {
			*(int *)arg = 0;
			break;
		}

		ret = uvc_query_ctrl(video->dev, GET_CUR, video->selector->id,
			video->dev->intfnum, SU_INPUT_SELECT_CONTROL,
			&input, 1);
		if (ret < 0)
			return ret;

		*(int *)arg = input - 1;
		break;
	}

	case VIDIOC_S_INPUT:
	{
		u8 input = *(u32 *)arg + 1;

		if ((ret = uvc_acquire_privileges(handle)) < 0)
			return ret;

		if (video->selector == NULL ||
		    (video->dev->quirks & UVC_QUIRK_IGNORE_SELECTOR_UNIT)) {
			if (input != 1)
				return -EINVAL;
			break;
		}

		if (input > video->selector->selector.bNrInPins)
			return -EINVAL;

		return uvc_query_ctrl(video->dev, SET_CUR, video->selector->id,
			video->dev->intfnum, SU_INPUT_SELECT_CONTROL,
			&input, 1);
	}

	/* Try, Get, Set & Enum format */
	case VIDIOC_ENUM_FMT:
	{
		struct v4l2_fmtdesc *fmt = arg;
		struct uvc_format *format;

		if (fmt->type != video->streaming->type ||
		    fmt->index >= video->streaming->nformats)
			return -EINVAL;

		format = &video->streaming->format[fmt->index];
		fmt->flags = 0;
		if (format->flags & UVC_FMT_FLAG_COMPRESSED)
			fmt->flags |= V4L2_FMT_FLAG_COMPRESSED;
		strncpy(fmt->description, format->name,
			sizeof fmt->description);
		fmt->description[sizeof fmt->description - 1] = 0;
		fmt->pixelformat = format->fcc;
		break;
	}

	case VIDIOC_TRY_FMT:
	{
		struct uvc_streaming_control probe;

		if ((ret = uvc_acquire_privileges(handle)) < 0)
			return ret;

		return uvc_v4l2_try_format(video, arg, &probe, NULL, NULL);
	}

	case VIDIOC_S_FMT:
		if ((ret = uvc_acquire_privileges(handle)) < 0)
			return ret;

		return uvc_v4l2_set_format(video, arg);

	case VIDIOC_G_FMT:
		return uvc_v4l2_get_format(video, arg);

	/* Frame size enumeration */
	case VIDIOC_ENUM_FRAMESIZES:
	{
		struct v4l2_frmsizeenum *fsize = arg;
		struct uvc_format *format = NULL;
		struct uvc_frame *frame;
		int i;

		/* Look for the given pixel format */
		for (i = 0; i < video->streaming->nformats; i++) {
			if (video->streaming->format[i].fcc ==
					fsize->pixel_format) {
				format = &video->streaming->format[i];
				break;
			}
		}
		if (format == NULL)
			return -EINVAL;

		if (fsize->index >= format->nframes)
			return -EINVAL;

		frame = &format->frame[fsize->index];
		fsize->type = V4L2_FRMSIZE_TYPE_DISCRETE;
		fsize->discrete.width = frame->wWidth;
		fsize->discrete.height = frame->wHeight;
		break;
	}

	/* Frame interval enumeration */
	case VIDIOC_ENUM_FRAMEINTERVALS:
	{
		struct v4l2_frmivalenum *fival = arg;
		struct uvc_format *format = NULL;
		struct uvc_frame *frame = NULL;
		int i;

		/* Look for the given pixel format and frame size */
		for (i = 0; i < video->streaming->nformats; i++) {
			if (video->streaming->format[i].fcc ==
					fival->pixel_format) {
				format = &video->streaming->format[i];
				break;
			}
		}
		if (format == NULL)
			return -EINVAL;

		for (i = 0; i < format->nframes; i++) {
			if (format->frame[i].wWidth == fival->width &&
			    format->frame[i].wHeight == fival->height) {
				frame = &format->frame[i];
				break;
			}
		}
		if (frame == NULL)
			return -EINVAL;

		if (frame->bFrameIntervalType) {
			if (fival->index >= frame->bFrameIntervalType)
				return -EINVAL;

			fival->type = V4L2_FRMIVAL_TYPE_DISCRETE;
			fival->discrete.numerator =
				frame->dwFrameInterval[fival->index];
			fival->discrete.denominator = 10000000;
			uvc_simplify_fraction(&fival->discrete.numerator,
				&fival->discrete.denominator, 8, 333);
		} else {
			fival->type = V4L2_FRMIVAL_TYPE_STEPWISE;
			fival->stepwise.min.numerator =
				frame->dwFrameInterval[0];
			fival->stepwise.min.denominator = 10000000;
			fival->stepwise.max.numerator =
				frame->dwFrameInterval[1];
			fival->stepwise.max.denominator = 10000000;
			fival->stepwise.step.numerator =
				frame->dwFrameInterval[2];
			fival->stepwise.step.denominator = 10000000;
			uvc_simplify_fraction(&fival->stepwise.min.numerator,
				&fival->stepwise.min.denominator, 8, 333);
			uvc_simplify_fraction(&fival->stepwise.max.numerator,
				&fival->stepwise.max.denominator, 8, 333);
			uvc_simplify_fraction(&fival->stepwise.step.numerator,
				&fival->stepwise.step.denominator, 8, 333);
		}
		break;
	}

	/* Get & Set streaming parameters */
	case VIDIOC_G_PARM:
		return uvc_v4l2_get_streamparm(video, arg);

	case VIDIOC_S_PARM:
		if ((ret = uvc_acquire_privileges(handle)) < 0)
			return ret;

		return uvc_v4l2_set_streamparm(video, arg);

	/* Cropping and scaling */
	case VIDIOC_CROPCAP:
	{
		struct v4l2_cropcap *ccap = arg;
		struct uvc_frame *frame = video->streaming->cur_frame;

		if (ccap->type != video->streaming->type)
			return -EINVAL;

		ccap->bounds.left = 0;
		ccap->bounds.top = 0;
		ccap->bounds.width = frame->wWidth;
		ccap->bounds.height = frame->wHeight;

		ccap->defrect = ccap->bounds;

		ccap->pixelaspect.numerator = 1;
		ccap->pixelaspect.denominator = 1;
		break;
	}

	case VIDIOC_G_CROP:
	case VIDIOC_S_CROP:
		return -EINVAL;

	/* Buffers & streaming */
	case VIDIOC_REQBUFS:
	{
		struct v4l2_requestbuffers *rb = arg;
		unsigned int bufsize =
			video->streaming->ctrl.dwMaxVideoFrameSize;

		if (rb->type != video->streaming->type ||
		    rb->memory != V4L2_MEMORY_MMAP)
			return -EINVAL;

		if ((ret = uvc_acquire_privileges(handle)) < 0)
			return ret;

		ret = uvc_alloc_buffers(&video->queue, rb->count, bufsize);
		if (ret < 0)
			return ret;

		rb->count = ret;
		ret = 0;
		break;
	}

	case VIDIOC_QUERYBUF:
	{
		struct v4l2_buffer *buf = arg;

		if (buf->type != video->streaming->type)
			return -EINVAL;

		if (!uvc_has_privileges(handle))
			return -EBUSY;

		return uvc_query_buffer(&video->queue, buf);
	}

	case VIDIOC_QBUF:
		if (!uvc_has_privileges(handle))
			return -EBUSY;

		return uvc_queue_buffer(&video->queue, arg);

	case VIDIOC_DQBUF:
		if (!uvc_has_privileges(handle))
			return -EBUSY;

		return uvc_dequeue_buffer(&video->queue, arg,
			file->f_flags & O_NONBLOCK);

	case VIDIOC_STREAMON:
	{
		int *type = arg;

		if (*type != video->streaming->type)
			return -EINVAL;

		if (!uvc_has_privileges(handle))
			return -EBUSY;

		if ((ret = uvc_video_enable(video, 1)) < 0)
			return ret;
		break;
	}

	case VIDIOC_STREAMOFF:
	{
		int *type = arg;

		if (*type != video->streaming->type)
			return -EINVAL;

		if (!uvc_has_privileges(handle))
			return -EBUSY;

		return uvc_video_enable(video, 0);
	}

	/* Analog video standards make no sense for digital cameras. */
	case VIDIOC_ENUMSTD:
	case VIDIOC_QUERYSTD:
	case VIDIOC_G_STD:
	case VIDIOC_S_STD:

	case VIDIOC_OVERLAY:

	case VIDIOC_ENUMAUDIO:
	case VIDIOC_ENUMAUDOUT:

	case VIDIOC_ENUMOUTPUT:
		uvc_trace(UVC_TRACE_IOCTL, "Unsupported ioctl 0x%08x\n", cmd);
		return -EINVAL;

	/* Dynamic controls. */
	case UVCIOC_CTRL_ADD:
	{
		struct uvc_xu_control_info *xinfo = arg;
		struct uvc_control_info *info;

		if (!capable(CAP_SYS_ADMIN))
			return -EPERM;

		info = kzalloc(sizeof *info, GFP_KERNEL);
		if (info == NULL)
			return -ENOMEM;

		memcpy(info->entity, xinfo->entity, sizeof info->entity);
		info->index = xinfo->index;
		info->selector = xinfo->selector;
		info->size = xinfo->size;
		info->flags = xinfo->flags;

		info->flags |= UVC_CONTROL_GET_MIN | UVC_CONTROL_GET_MAX |
				UVC_CONTROL_GET_RES | UVC_CONTROL_GET_DEF;

		ret = uvc_ctrl_add_info(info);
		if (ret < 0)
			kfree(info);
		break;
	}

	case UVCIOC_CTRL_MAP:
	{
		struct uvc_xu_control_mapping *xmap = arg;
		struct uvc_control_mapping *map;

		if (!capable(CAP_SYS_ADMIN))
			return -EPERM;

		map = kzalloc(sizeof *map, GFP_KERNEL);
		if (map == NULL)
			return -ENOMEM;

		map->id = xmap->id;
		memcpy(map->name, xmap->name, sizeof map->name);
		memcpy(map->entity, xmap->entity, sizeof map->entity);
		map->selector = xmap->selector;
		map->size = xmap->size;
		map->offset = xmap->offset;
		map->v4l2_type = xmap->v4l2_type;
		map->data_type = xmap->data_type;

		ret = uvc_ctrl_add_mapping(map);
		if (ret < 0)
			kfree(map);
		break;
	}

	case UVCIOC_CTRL_GET:
		return uvc_xu_ctrl_query(video, arg, 0);

	case UVCIOC_CTRL_SET:
		return uvc_xu_ctrl_query(video, arg, 1);

	default:
		if ((ret = v4l_compat_translate_ioctl(file, cmd, arg,
			uvc_v4l2_do_ioctl)) == -ENOIOCTLCMD)
			uvc_trace(UVC_TRACE_IOCTL, "Unknown ioctl 0x%08x\n",
				  cmd);
		return ret;
	}

	return ret;
}

static long uvc_v4l2_ioctl(struct file *file,
		     unsigned int cmd, unsigned long arg)
{
	if (uvc_trace_param & UVC_TRACE_IOCTL) {
		uvc_printk(KERN_DEBUG, "uvc_v4l2_ioctl(");
		v4l_printk_ioctl(cmd);
		printk(")\n");
	}

	return video_usercopy(file, cmd, arg, uvc_v4l2_do_ioctl);
}

static ssize_t uvc_v4l2_read(struct file *file, char __user *data,
		    size_t count, loff_t *ppos)
{
	uvc_trace(UVC_TRACE_CALLS, "uvc_v4l2_read: not implemented.\n");
	return -ENODEV;
}

/*
 * VMA operations.
 */
static void uvc_vm_open(struct vm_area_struct *vma)
{
	struct uvc_buffer *buffer = vma->vm_private_data;
	buffer->vma_use_count++;
}

static void uvc_vm_close(struct vm_area_struct *vma)
{
	struct uvc_buffer *buffer = vma->vm_private_data;
	buffer->vma_use_count--;
}

static struct vm_operations_struct uvc_vm_ops = {
	.open		= uvc_vm_open,
	.close		= uvc_vm_close,
};

static int uvc_v4l2_mmap(struct file *file, struct vm_area_struct *vma)
{
	struct uvc_video_device *video = video_drvdata(file);
	struct uvc_buffer *uninitialized_var(buffer);
	struct page *page;
	unsigned long addr, start, size;
	unsigned int i;
	int ret = 0;

	uvc_trace(UVC_TRACE_CALLS, "uvc_v4l2_mmap\n");

	start = vma->vm_start;
	size = vma->vm_end - vma->vm_start;

	mutex_lock(&video->queue.mutex);

	for (i = 0; i < video->queue.count; ++i) {
		buffer = &video->queue.buffer[i];
		if ((buffer->buf.m.offset >> PAGE_SHIFT) == vma->vm_pgoff)
			break;
	}

	if (i == video->queue.count || size != video->queue.buf_size) {
		ret = -EINVAL;
		goto done;
	}

	/*
	 * VM_IO marks the area as being an mmaped region for I/O to a
	 * device. It also prevents the region from being core dumped.
	 */
	vma->vm_flags |= VM_IO;

	addr = (unsigned long)video->queue.mem + buffer->buf.m.offset;
	while (size > 0) {
		page = vmalloc_to_page((void *)addr);
		if ((ret = vm_insert_page(vma, start, page)) < 0)
			goto done;

		start += PAGE_SIZE;
		addr += PAGE_SIZE;
		size -= PAGE_SIZE;
	}

	vma->vm_ops = &uvc_vm_ops;
	vma->vm_private_data = buffer;
	uvc_vm_open(vma);

done:
	mutex_unlock(&video->queue.mutex);
	return ret;
}

static unsigned int uvc_v4l2_poll(struct file *file, poll_table *wait)
{
	struct uvc_video_device *video = video_drvdata(file);

	uvc_trace(UVC_TRACE_CALLS, "uvc_v4l2_poll\n");

	return uvc_queue_poll(&video->queue, file, wait);
}

const struct v4l2_file_operations uvc_fops = {
	.owner		= THIS_MODULE,
	.open		= uvc_v4l2_open,
	.release	= uvc_v4l2_release,
	.ioctl		= uvc_v4l2_ioctl,
	.read		= uvc_v4l2_read,
	.mmap		= uvc_v4l2_mmap,
	.poll		= uvc_v4l2_poll,
};