summaryrefslogtreecommitdiff
path: root/drivers/media/v4l2-core/videobuf2-v4l2.c
blob: 52ef8833f6b6c7afe7ce5a6eadce7eb4157a4a61 (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
946
947
948
949
950
951
952
953
954
955
956
957
958
959
960
961
962
963
/*
 * videobuf2-v4l2.c - V4L2 driver helper framework
 *
 * Copyright (C) 2010 Samsung Electronics
 *
 * Author: Pawel Osciak <pawel@osciak.com>
 *	   Marek Szyprowski <m.szyprowski@samsung.com>
 *
 * The vb2_thread implementation was based on code from videobuf-dvb.c:
 *	(c) 2004 Gerd Knorr <kraxel@bytesex.org> [SUSE Labs]
 *
 * 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.
 */

#include <linux/err.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/mm.h>
#include <linux/poll.h>
#include <linux/slab.h>
#include <linux/sched.h>
#include <linux/freezer.h>
#include <linux/kthread.h>

#include <media/v4l2-dev.h>
#include <media/v4l2-fh.h>
#include <media/v4l2-event.h>
#include <media/v4l2-common.h>

#include <media/videobuf2-v4l2.h>

static int debug;
module_param(debug, int, 0644);

#define dprintk(level, fmt, arg...)					      \
	do {								      \
		if (debug >= level)					      \
			pr_info("vb2-v4l2: %s: " fmt, __func__, ## arg); \
	} while (0)

/* Flags that are set by the vb2 core */
#define V4L2_BUFFER_MASK_FLAGS	(V4L2_BUF_FLAG_MAPPED | V4L2_BUF_FLAG_QUEUED | \
				 V4L2_BUF_FLAG_DONE | V4L2_BUF_FLAG_ERROR | \
				 V4L2_BUF_FLAG_PREPARED | \
				 V4L2_BUF_FLAG_TIMESTAMP_MASK)
/* Output buffer flags that should be passed on to the driver */
#define V4L2_BUFFER_OUT_FLAGS	(V4L2_BUF_FLAG_PFRAME | V4L2_BUF_FLAG_BFRAME | \
				 V4L2_BUF_FLAG_KEYFRAME | V4L2_BUF_FLAG_TIMECODE)

/**
 * __verify_planes_array() - verify that the planes array passed in struct
 * v4l2_buffer from userspace can be safely used
 */
static int __verify_planes_array(struct vb2_buffer *vb, const struct v4l2_buffer *b)
{
	if (!V4L2_TYPE_IS_MULTIPLANAR(b->type))
		return 0;

	/* Is memory for copying plane information present? */
	if (b->m.planes == NULL) {
		dprintk(1, "multi-planar buffer passed but "
			   "planes array not provided\n");
		return -EINVAL;
	}

	if (b->length < vb->num_planes || b->length > VB2_MAX_PLANES) {
		dprintk(1, "incorrect planes array length, "
			   "expected %d, got %d\n", vb->num_planes, b->length);
		return -EINVAL;
	}

	return 0;
}

static int __verify_planes_array_core(struct vb2_buffer *vb, const void *pb)
{
	return __verify_planes_array(vb, pb);
}

/**
 * __verify_length() - Verify that the bytesused value for each plane fits in
 * the plane length and that the data offset doesn't exceed the bytesused value.
 */
static int __verify_length(struct vb2_buffer *vb, const struct v4l2_buffer *b)
{
	unsigned int length;
	unsigned int bytesused;
	unsigned int plane;

	if (!V4L2_TYPE_IS_OUTPUT(b->type))
		return 0;

	if (V4L2_TYPE_IS_MULTIPLANAR(b->type)) {
		for (plane = 0; plane < vb->num_planes; ++plane) {
			length = (b->memory == VB2_MEMORY_USERPTR ||
				  b->memory == VB2_MEMORY_DMABUF)
			       ? b->m.planes[plane].length
				: vb->planes[plane].length;
			bytesused = b->m.planes[plane].bytesused
				  ? b->m.planes[plane].bytesused : length;

			if (b->m.planes[plane].bytesused > length)
				return -EINVAL;

			if (b->m.planes[plane].data_offset > 0 &&
			    b->m.planes[plane].data_offset >= bytesused)
				return -EINVAL;
		}
	} else {
		length = (b->memory == VB2_MEMORY_USERPTR)
			? b->length : vb->planes[0].length;

		if (b->bytesused > length)
			return -EINVAL;
	}

	return 0;
}

static void __copy_timestamp(struct vb2_buffer *vb, const void *pb)
{
	const struct v4l2_buffer *b = pb;
	struct vb2_v4l2_buffer *vbuf = to_vb2_v4l2_buffer(vb);
	struct vb2_queue *q = vb->vb2_queue;

	if (q->is_output) {
		/*
		 * For output buffers copy the timestamp if needed,
		 * and the timecode field and flag if needed.
		 */
		if (q->copy_timestamp)
			vb->timestamp = timeval_to_ns(&b->timestamp);
		vbuf->flags |= b->flags & V4L2_BUF_FLAG_TIMECODE;
		if (b->flags & V4L2_BUF_FLAG_TIMECODE)
			vbuf->timecode = b->timecode;
	}
};

static void vb2_warn_zero_bytesused(struct vb2_buffer *vb)
{
	static bool check_once;

	if (check_once)
		return;

	check_once = true;
	WARN_ON(1);

	pr_warn("use of bytesused == 0 is deprecated and will be removed in the future,\n");
	if (vb->vb2_queue->allow_zero_bytesused)
		pr_warn("use VIDIOC_DECODER_CMD(V4L2_DEC_CMD_STOP) instead.\n");
	else
		pr_warn("use the actual size instead.\n");
}

static int vb2_queue_or_prepare_buf(struct vb2_queue *q, struct v4l2_buffer *b,
				    const char *opname)
{
	if (b->type != q->type) {
		dprintk(1, "%s: invalid buffer type\n", opname);
		return -EINVAL;
	}

	if (b->index >= q->num_buffers) {
		dprintk(1, "%s: buffer index out of range\n", opname);
		return -EINVAL;
	}

	if (q->bufs[b->index] == NULL) {
		/* Should never happen */
		dprintk(1, "%s: buffer is NULL\n", opname);
		return -EINVAL;
	}

	if (b->memory != q->memory) {
		dprintk(1, "%s: invalid memory type\n", opname);
		return -EINVAL;
	}

	return __verify_planes_array(q->bufs[b->index], b);
}

/**
 * __fill_v4l2_buffer() - fill in a struct v4l2_buffer with information to be
 * returned to userspace
 */
static void __fill_v4l2_buffer(struct vb2_buffer *vb, void *pb)
{
	struct v4l2_buffer *b = pb;
	struct vb2_v4l2_buffer *vbuf = to_vb2_v4l2_buffer(vb);
	struct vb2_queue *q = vb->vb2_queue;
	unsigned int plane;

	/* Copy back data such as timestamp, flags, etc. */
	b->index = vb->index;
	b->type = vb->type;
	b->memory = vb->memory;
	b->bytesused = 0;

	b->flags = vbuf->flags;
	b->field = vbuf->field;
	b->timestamp = ns_to_timeval(vb->timestamp);
	b->timecode = vbuf->timecode;
	b->sequence = vbuf->sequence;
	b->reserved2 = 0;
	b->reserved = 0;

	if (q->is_multiplanar) {
		/*
		 * Fill in plane-related data if userspace provided an array
		 * for it. The caller has already verified memory and size.
		 */
		b->length = vb->num_planes;
		for (plane = 0; plane < vb->num_planes; ++plane) {
			struct v4l2_plane *pdst = &b->m.planes[plane];
			struct vb2_plane *psrc = &vb->planes[plane];

			pdst->bytesused = psrc->bytesused;
			pdst->length = psrc->length;
			if (q->memory == VB2_MEMORY_MMAP)
				pdst->m.mem_offset = psrc->m.offset;
			else if (q->memory == VB2_MEMORY_USERPTR)
				pdst->m.userptr = psrc->m.userptr;
			else if (q->memory == VB2_MEMORY_DMABUF)
				pdst->m.fd = psrc->m.fd;
			pdst->data_offset = psrc->data_offset;
			memset(pdst->reserved, 0, sizeof(pdst->reserved));
		}
	} else {
		/*
		 * We use length and offset in v4l2_planes array even for
		 * single-planar buffers, but userspace does not.
		 */
		b->length = vb->planes[0].length;
		b->bytesused = vb->planes[0].bytesused;
		if (q->memory == VB2_MEMORY_MMAP)
			b->m.offset = vb->planes[0].m.offset;
		else if (q->memory == VB2_MEMORY_USERPTR)
			b->m.userptr = vb->planes[0].m.userptr;
		else if (q->memory == VB2_MEMORY_DMABUF)
			b->m.fd = vb->planes[0].m.fd;
	}

	/*
	 * Clear any buffer state related flags.
	 */
	b->flags &= ~V4L2_BUFFER_MASK_FLAGS;
	b->flags |= q->timestamp_flags & V4L2_BUF_FLAG_TIMESTAMP_MASK;
	if (!q->copy_timestamp) {
		/*
		 * For non-COPY timestamps, drop timestamp source bits
		 * and obtain the timestamp source from the queue.
		 */
		b->flags &= ~V4L2_BUF_FLAG_TSTAMP_SRC_MASK;
		b->flags |= q->timestamp_flags & V4L2_BUF_FLAG_TSTAMP_SRC_MASK;
	}

	switch (vb->state) {
	case VB2_BUF_STATE_QUEUED:
	case VB2_BUF_STATE_ACTIVE:
		b->flags |= V4L2_BUF_FLAG_QUEUED;
		break;
	case VB2_BUF_STATE_ERROR:
		b->flags |= V4L2_BUF_FLAG_ERROR;
		/* fall through */
	case VB2_BUF_STATE_DONE:
		b->flags |= V4L2_BUF_FLAG_DONE;
		break;
	case VB2_BUF_STATE_PREPARED:
		b->flags |= V4L2_BUF_FLAG_PREPARED;
		break;
	case VB2_BUF_STATE_PREPARING:
	case VB2_BUF_STATE_DEQUEUED:
	case VB2_BUF_STATE_REQUEUEING:
		/* nothing */
		break;
	}

	if (vb2_buffer_in_use(q, vb))
		b->flags |= V4L2_BUF_FLAG_MAPPED;

	if (!q->is_output &&
		b->flags & V4L2_BUF_FLAG_DONE &&
		b->flags & V4L2_BUF_FLAG_LAST)
		q->last_buffer_dequeued = true;
}

/**
 * __fill_vb2_buffer() - fill a vb2_buffer with information provided in a
 * v4l2_buffer by the userspace. It also verifies that struct
 * v4l2_buffer has a valid number of planes.
 */
static int __fill_vb2_buffer(struct vb2_buffer *vb,
		const void *pb, struct vb2_plane *planes)
{
	struct vb2_queue *q = vb->vb2_queue;
	const struct v4l2_buffer *b = pb;
	struct vb2_v4l2_buffer *vbuf = to_vb2_v4l2_buffer(vb);
	unsigned int plane;
	int ret;

	ret = __verify_length(vb, b);
	if (ret < 0) {
		dprintk(1, "plane parameters verification failed: %d\n", ret);
		return ret;
	}
	if (b->field == V4L2_FIELD_ALTERNATE && q->is_output) {
		/*
		 * If the format's field is ALTERNATE, then the buffer's field
		 * should be either TOP or BOTTOM, not ALTERNATE since that
		 * makes no sense. The driver has to know whether the
		 * buffer represents a top or a bottom field in order to
		 * program any DMA correctly. Using ALTERNATE is wrong, since
		 * that just says that it is either a top or a bottom field,
		 * but not which of the two it is.
		 */
		dprintk(1, "the field is incorrectly set to ALTERNATE "
					"for an output buffer\n");
		return -EINVAL;
	}
	vb->timestamp = 0;
	vbuf->sequence = 0;

	if (V4L2_TYPE_IS_MULTIPLANAR(b->type)) {
		if (b->memory == VB2_MEMORY_USERPTR) {
			for (plane = 0; plane < vb->num_planes; ++plane) {
				planes[plane].m.userptr =
					b->m.planes[plane].m.userptr;
				planes[plane].length =
					b->m.planes[plane].length;
			}
		}
		if (b->memory == VB2_MEMORY_DMABUF) {
			for (plane = 0; plane < vb->num_planes; ++plane) {
				planes[plane].m.fd =
					b->m.planes[plane].m.fd;
				planes[plane].length =
					b->m.planes[plane].length;
			}
		}

		/* Fill in driver-provided information for OUTPUT types */
		if (V4L2_TYPE_IS_OUTPUT(b->type)) {
			/*
			 * Will have to go up to b->length when API starts
			 * accepting variable number of planes.
			 *
			 * If bytesused == 0 for the output buffer, then fall
			 * back to the full buffer size. In that case
			 * userspace clearly never bothered to set it and
			 * it's a safe assumption that they really meant to
			 * use the full plane sizes.
			 *
			 * Some drivers, e.g. old codec drivers, use bytesused == 0
			 * as a way to indicate that streaming is finished.
			 * In that case, the driver should use the
			 * allow_zero_bytesused flag to keep old userspace
			 * applications working.
			 */
			for (plane = 0; plane < vb->num_planes; ++plane) {
				struct vb2_plane *pdst = &planes[plane];
				struct v4l2_plane *psrc = &b->m.planes[plane];

				if (psrc->bytesused == 0)
					vb2_warn_zero_bytesused(vb);

				if (vb->vb2_queue->allow_zero_bytesused)
					pdst->bytesused = psrc->bytesused;
				else
					pdst->bytesused = psrc->bytesused ?
						psrc->bytesused : pdst->length;
				pdst->data_offset = psrc->data_offset;
			}
		}
	} else {
		/*
		 * Single-planar buffers do not use planes array,
		 * so fill in relevant v4l2_buffer struct fields instead.
		 * In videobuf we use our internal V4l2_planes struct for
		 * single-planar buffers as well, for simplicity.
		 *
		 * If bytesused == 0 for the output buffer, then fall back
		 * to the full buffer size as that's a sensible default.
		 *
		 * Some drivers, e.g. old codec drivers, use bytesused == 0 as
		 * a way to indicate that streaming is finished. In that case,
		 * the driver should use the allow_zero_bytesused flag to keep
		 * old userspace applications working.
		 */
		if (b->memory == VB2_MEMORY_USERPTR) {
			planes[0].m.userptr = b->m.userptr;
			planes[0].length = b->length;
		}

		if (b->memory == VB2_MEMORY_DMABUF) {
			planes[0].m.fd = b->m.fd;
			planes[0].length = b->length;
		}

		if (V4L2_TYPE_IS_OUTPUT(b->type)) {
			if (b->bytesused == 0)
				vb2_warn_zero_bytesused(vb);

			if (vb->vb2_queue->allow_zero_bytesused)
				planes[0].bytesused = b->bytesused;
			else
				planes[0].bytesused = b->bytesused ?
					b->bytesused : planes[0].length;
		} else
			planes[0].bytesused = 0;

	}

	/* Zero flags that the vb2 core handles */
	vbuf->flags = b->flags & ~V4L2_BUFFER_MASK_FLAGS;
	if (!vb->vb2_queue->copy_timestamp || !V4L2_TYPE_IS_OUTPUT(b->type)) {
		/*
		 * Non-COPY timestamps and non-OUTPUT queues will get
		 * their timestamp and timestamp source flags from the
		 * queue.
		 */
		vbuf->flags &= ~V4L2_BUF_FLAG_TSTAMP_SRC_MASK;
	}

	if (V4L2_TYPE_IS_OUTPUT(b->type)) {
		/*
		 * For output buffers mask out the timecode flag:
		 * this will be handled later in vb2_qbuf().
		 * The 'field' is valid metadata for this output buffer
		 * and so that needs to be copied here.
		 */
		vbuf->flags &= ~V4L2_BUF_FLAG_TIMECODE;
		vbuf->field = b->field;
	} else {
		/* Zero any output buffer flags as this is a capture buffer */
		vbuf->flags &= ~V4L2_BUFFER_OUT_FLAGS;
	}

	return 0;
}

static const struct vb2_buf_ops v4l2_buf_ops = {
	.verify_planes_array	= __verify_planes_array_core,
	.fill_user_buffer	= __fill_v4l2_buffer,
	.fill_vb2_buffer	= __fill_vb2_buffer,
	.copy_timestamp		= __copy_timestamp,
};

/**
 * vb2_querybuf() - query video buffer information
 * @q:		videobuf queue
 * @b:		buffer struct passed from userspace to vidioc_querybuf handler
 *		in driver
 *
 * Should be called from vidioc_querybuf ioctl handler in driver.
 * This function will verify the passed v4l2_buffer structure and fill the
 * relevant information for the userspace.
 *
 * The return values from this function are intended to be directly returned
 * from vidioc_querybuf handler in driver.
 */
int vb2_querybuf(struct vb2_queue *q, struct v4l2_buffer *b)
{
	struct vb2_buffer *vb;
	int ret;

	if (b->type != q->type) {
		dprintk(1, "wrong buffer type\n");
		return -EINVAL;
	}

	if (b->index >= q->num_buffers) {
		dprintk(1, "buffer index out of range\n");
		return -EINVAL;
	}
	vb = q->bufs[b->index];
	ret = __verify_planes_array(vb, b);
	if (!ret)
		vb2_core_querybuf(q, b->index, b);
	return ret;
}
EXPORT_SYMBOL(vb2_querybuf);

int vb2_reqbufs(struct vb2_queue *q, struct v4l2_requestbuffers *req)
{
	int ret = vb2_verify_memory_type(q, req->memory, req->type);

	return ret ? ret : vb2_core_reqbufs(q, req->memory, &req->count);
}
EXPORT_SYMBOL_GPL(vb2_reqbufs);

int vb2_prepare_buf(struct vb2_queue *q, struct v4l2_buffer *b)
{
	int ret;

	if (vb2_fileio_is_active(q)) {
		dprintk(1, "file io in progress\n");
		return -EBUSY;
	}

	ret = vb2_queue_or_prepare_buf(q, b, "prepare_buf");

	return ret ? ret : vb2_core_prepare_buf(q, b->index, b);
}
EXPORT_SYMBOL_GPL(vb2_prepare_buf);

int vb2_create_bufs(struct vb2_queue *q, struct v4l2_create_buffers *create)
{
	unsigned requested_planes = 1;
	unsigned requested_sizes[VIDEO_MAX_PLANES];
	struct v4l2_format *f = &create->format;
	int ret = vb2_verify_memory_type(q, create->memory, f->type);
	unsigned i;

	create->index = q->num_buffers;
	if (create->count == 0)
		return ret != -EBUSY ? ret : 0;

	switch (f->type) {
	case V4L2_BUF_TYPE_VIDEO_CAPTURE_MPLANE:
	case V4L2_BUF_TYPE_VIDEO_OUTPUT_MPLANE:
		requested_planes = f->fmt.pix_mp.num_planes;
		if (requested_planes == 0 ||
		    requested_planes > VIDEO_MAX_PLANES)
			return -EINVAL;
		for (i = 0; i < requested_planes; i++)
			requested_sizes[i] =
				f->fmt.pix_mp.plane_fmt[i].sizeimage;
		break;
	case V4L2_BUF_TYPE_VIDEO_CAPTURE:
	case V4L2_BUF_TYPE_VIDEO_OUTPUT:
		requested_sizes[0] = f->fmt.pix.sizeimage;
		break;
	case V4L2_BUF_TYPE_VBI_CAPTURE:
	case V4L2_BUF_TYPE_VBI_OUTPUT:
		requested_sizes[0] = f->fmt.vbi.samples_per_line *
			(f->fmt.vbi.count[0] + f->fmt.vbi.count[1]);
		break;
	case V4L2_BUF_TYPE_SLICED_VBI_CAPTURE:
	case V4L2_BUF_TYPE_SLICED_VBI_OUTPUT:
		requested_sizes[0] = f->fmt.sliced.io_size;
		break;
	case V4L2_BUF_TYPE_SDR_CAPTURE:
	case V4L2_BUF_TYPE_SDR_OUTPUT:
		requested_sizes[0] = f->fmt.sdr.buffersize;
		break;
	default:
		return -EINVAL;
	}
	for (i = 0; i < requested_planes; i++)
		if (requested_sizes[i] == 0)
			return -EINVAL;
	return ret ? ret : vb2_core_create_bufs(q, create->memory,
		&create->count, requested_planes, requested_sizes);
}
EXPORT_SYMBOL_GPL(vb2_create_bufs);

int vb2_qbuf(struct vb2_queue *q, struct v4l2_buffer *b)
{
	int ret;

	if (vb2_fileio_is_active(q)) {
		dprintk(1, "file io in progress\n");
		return -EBUSY;
	}

	ret = vb2_queue_or_prepare_buf(q, b, "qbuf");
	return ret ? ret : vb2_core_qbuf(q, b->index, b);
}
EXPORT_SYMBOL_GPL(vb2_qbuf);

int vb2_dqbuf(struct vb2_queue *q, struct v4l2_buffer *b, bool nonblocking)
{
	int ret;

	if (vb2_fileio_is_active(q)) {
		dprintk(1, "file io in progress\n");
		return -EBUSY;
	}

	if (b->type != q->type) {
		dprintk(1, "invalid buffer type\n");
		return -EINVAL;
	}

	ret = vb2_core_dqbuf(q, NULL, b, nonblocking);

	/*
	 *  After calling the VIDIOC_DQBUF V4L2_BUF_FLAG_DONE must be
	 *  cleared.
	 */
	b->flags &= ~V4L2_BUF_FLAG_DONE;

	return ret;
}
EXPORT_SYMBOL_GPL(vb2_dqbuf);

int vb2_streamon(struct vb2_queue *q, enum v4l2_buf_type type)
{
	if (vb2_fileio_is_active(q)) {
		dprintk(1, "file io in progress\n");
		return -EBUSY;
	}
	return vb2_core_streamon(q, type);
}
EXPORT_SYMBOL_GPL(vb2_streamon);

int vb2_streamoff(struct vb2_queue *q, enum v4l2_buf_type type)
{
	if (vb2_fileio_is_active(q)) {
		dprintk(1, "file io in progress\n");
		return -EBUSY;
	}
	return vb2_core_streamoff(q, type);
}
EXPORT_SYMBOL_GPL(vb2_streamoff);

int vb2_expbuf(struct vb2_queue *q, struct v4l2_exportbuffer *eb)
{
	return vb2_core_expbuf(q, &eb->fd, eb->type, eb->index,
				eb->plane, eb->flags);
}
EXPORT_SYMBOL_GPL(vb2_expbuf);

int vb2_queue_init(struct vb2_queue *q)
{
	/*
	 * Sanity check
	 */
	if (WARN_ON(!q)			  ||
	    WARN_ON(q->timestamp_flags &
		    ~(V4L2_BUF_FLAG_TIMESTAMP_MASK |
		      V4L2_BUF_FLAG_TSTAMP_SRC_MASK)))
		return -EINVAL;

	/* Warn that the driver should choose an appropriate timestamp type */
	WARN_ON((q->timestamp_flags & V4L2_BUF_FLAG_TIMESTAMP_MASK) ==
		V4L2_BUF_FLAG_TIMESTAMP_UNKNOWN);

	/* Warn that vb2_memory should match with v4l2_memory */
	if (WARN_ON(VB2_MEMORY_MMAP != (int)V4L2_MEMORY_MMAP)
		|| WARN_ON(VB2_MEMORY_USERPTR != (int)V4L2_MEMORY_USERPTR)
		|| WARN_ON(VB2_MEMORY_DMABUF != (int)V4L2_MEMORY_DMABUF))
		return -EINVAL;

	if (q->buf_struct_size == 0)
		q->buf_struct_size = sizeof(struct vb2_v4l2_buffer);

	q->buf_ops = &v4l2_buf_ops;
	q->is_multiplanar = V4L2_TYPE_IS_MULTIPLANAR(q->type);
	q->is_output = V4L2_TYPE_IS_OUTPUT(q->type);
	q->copy_timestamp = (q->timestamp_flags & V4L2_BUF_FLAG_TIMESTAMP_MASK)
			== V4L2_BUF_FLAG_TIMESTAMP_COPY;
	/*
	 * For compatibility with vb1: if QBUF hasn't been called yet, then
	 * return POLLERR as well. This only affects capture queues, output
	 * queues will always initialize waiting_for_buffers to false.
	 */
	q->quirk_poll_must_check_waiting_for_buffers = true;

	return vb2_core_queue_init(q);
}
EXPORT_SYMBOL_GPL(vb2_queue_init);

void vb2_queue_release(struct vb2_queue *q)
{
	vb2_core_queue_release(q);
}
EXPORT_SYMBOL_GPL(vb2_queue_release);

unsigned int vb2_poll(struct vb2_queue *q, struct file *file, poll_table *wait)
{
	struct video_device *vfd = video_devdata(file);
	unsigned long req_events = poll_requested_events(wait);
	unsigned int res = 0;

	if (test_bit(V4L2_FL_USES_V4L2_FH, &vfd->flags)) {
		struct v4l2_fh *fh = file->private_data;

		if (v4l2_event_pending(fh))
			res = POLLPRI;
		else if (req_events & POLLPRI)
			poll_wait(file, &fh->wait, wait);
	}

	return res | vb2_core_poll(q, file, wait);
}
EXPORT_SYMBOL_GPL(vb2_poll);

/*
 * The following functions are not part of the vb2 core API, but are helper
 * functions that plug into struct v4l2_ioctl_ops, struct v4l2_file_operations
 * and struct vb2_ops.
 * They contain boilerplate code that most if not all drivers have to do
 * and so they simplify the driver code.
 */

/* The queue is busy if there is a owner and you are not that owner. */
static inline bool vb2_queue_is_busy(struct video_device *vdev, struct file *file)
{
	return vdev->queue->owner && vdev->queue->owner != file->private_data;
}

/* vb2 ioctl helpers */

int vb2_ioctl_reqbufs(struct file *file, void *priv,
			  struct v4l2_requestbuffers *p)
{
	struct video_device *vdev = video_devdata(file);
	int res = vb2_verify_memory_type(vdev->queue, p->memory, p->type);

	if (res)
		return res;
	if (vb2_queue_is_busy(vdev, file))
		return -EBUSY;
	res = vb2_core_reqbufs(vdev->queue, p->memory, &p->count);
	/* If count == 0, then the owner has released all buffers and he
	   is no longer owner of the queue. Otherwise we have a new owner. */
	if (res == 0)
		vdev->queue->owner = p->count ? file->private_data : NULL;
	return res;
}
EXPORT_SYMBOL_GPL(vb2_ioctl_reqbufs);

int vb2_ioctl_create_bufs(struct file *file, void *priv,
			  struct v4l2_create_buffers *p)
{
	struct video_device *vdev = video_devdata(file);
	int res = vb2_verify_memory_type(vdev->queue, p->memory,
			p->format.type);

	p->index = vdev->queue->num_buffers;
	/*
	 * If count == 0, then just check if memory and type are valid.
	 * Any -EBUSY result from vb2_verify_memory_type can be mapped to 0.
	 */
	if (p->count == 0)
		return res != -EBUSY ? res : 0;
	if (res)
		return res;
	if (vb2_queue_is_busy(vdev, file))
		return -EBUSY;

	res = vb2_create_bufs(vdev->queue, p);
	if (res == 0)
		vdev->queue->owner = file->private_data;
	return res;
}
EXPORT_SYMBOL_GPL(vb2_ioctl_create_bufs);

int vb2_ioctl_prepare_buf(struct file *file, void *priv,
			  struct v4l2_buffer *p)
{
	struct video_device *vdev = video_devdata(file);

	if (vb2_queue_is_busy(vdev, file))
		return -EBUSY;
	return vb2_prepare_buf(vdev->queue, p);
}
EXPORT_SYMBOL_GPL(vb2_ioctl_prepare_buf);

int vb2_ioctl_querybuf(struct file *file, void *priv, struct v4l2_buffer *p)
{
	struct video_device *vdev = video_devdata(file);

	/* No need to call vb2_queue_is_busy(), anyone can query buffers. */
	return vb2_querybuf(vdev->queue, p);
}
EXPORT_SYMBOL_GPL(vb2_ioctl_querybuf);

int vb2_ioctl_qbuf(struct file *file, void *priv, struct v4l2_buffer *p)
{
	struct video_device *vdev = video_devdata(file);

	if (vb2_queue_is_busy(vdev, file))
		return -EBUSY;
	return vb2_qbuf(vdev->queue, p);
}
EXPORT_SYMBOL_GPL(vb2_ioctl_qbuf);

int vb2_ioctl_dqbuf(struct file *file, void *priv, struct v4l2_buffer *p)
{
	struct video_device *vdev = video_devdata(file);

	if (vb2_queue_is_busy(vdev, file))
		return -EBUSY;
	return vb2_dqbuf(vdev->queue, p, file->f_flags & O_NONBLOCK);
}
EXPORT_SYMBOL_GPL(vb2_ioctl_dqbuf);

int vb2_ioctl_streamon(struct file *file, void *priv, enum v4l2_buf_type i)
{
	struct video_device *vdev = video_devdata(file);

	if (vb2_queue_is_busy(vdev, file))
		return -EBUSY;
	return vb2_streamon(vdev->queue, i);
}
EXPORT_SYMBOL_GPL(vb2_ioctl_streamon);

int vb2_ioctl_streamoff(struct file *file, void *priv, enum v4l2_buf_type i)
{
	struct video_device *vdev = video_devdata(file);

	if (vb2_queue_is_busy(vdev, file))
		return -EBUSY;
	return vb2_streamoff(vdev->queue, i);
}
EXPORT_SYMBOL_GPL(vb2_ioctl_streamoff);

int vb2_ioctl_expbuf(struct file *file, void *priv, struct v4l2_exportbuffer *p)
{
	struct video_device *vdev = video_devdata(file);

	if (vb2_queue_is_busy(vdev, file))
		return -EBUSY;
	return vb2_expbuf(vdev->queue, p);
}
EXPORT_SYMBOL_GPL(vb2_ioctl_expbuf);

/* v4l2_file_operations helpers */

int vb2_fop_mmap(struct file *file, struct vm_area_struct *vma)
{
	struct video_device *vdev = video_devdata(file);

	return vb2_mmap(vdev->queue, vma);
}
EXPORT_SYMBOL_GPL(vb2_fop_mmap);

int _vb2_fop_release(struct file *file, struct mutex *lock)
{
	struct video_device *vdev = video_devdata(file);

	if (lock)
		mutex_lock(lock);
	if (file->private_data == vdev->queue->owner) {
		vb2_queue_release(vdev->queue);
		vdev->queue->owner = NULL;
	}
	if (lock)
		mutex_unlock(lock);
	return v4l2_fh_release(file);
}
EXPORT_SYMBOL_GPL(_vb2_fop_release);

int vb2_fop_release(struct file *file)
{
	struct video_device *vdev = video_devdata(file);
	struct mutex *lock = vdev->queue->lock ? vdev->queue->lock : vdev->lock;

	return _vb2_fop_release(file, lock);
}
EXPORT_SYMBOL_GPL(vb2_fop_release);

ssize_t vb2_fop_write(struct file *file, const char __user *buf,
		size_t count, loff_t *ppos)
{
	struct video_device *vdev = video_devdata(file);
	struct mutex *lock = vdev->queue->lock ? vdev->queue->lock : vdev->lock;
	int err = -EBUSY;

	if (!(vdev->queue->io_modes & VB2_WRITE))
		return -EINVAL;
	if (lock && mutex_lock_interruptible(lock))
		return -ERESTARTSYS;
	if (vb2_queue_is_busy(vdev, file))
		goto exit;
	err = vb2_write(vdev->queue, buf, count, ppos,
		       file->f_flags & O_NONBLOCK);
	if (vdev->queue->fileio)
		vdev->queue->owner = file->private_data;
exit:
	if (lock)
		mutex_unlock(lock);
	return err;
}
EXPORT_SYMBOL_GPL(vb2_fop_write);

ssize_t vb2_fop_read(struct file *file, char __user *buf,
		size_t count, loff_t *ppos)
{
	struct video_device *vdev = video_devdata(file);
	struct mutex *lock = vdev->queue->lock ? vdev->queue->lock : vdev->lock;
	int err = -EBUSY;

	if (!(vdev->queue->io_modes & VB2_READ))
		return -EINVAL;
	if (lock && mutex_lock_interruptible(lock))
		return -ERESTARTSYS;
	if (vb2_queue_is_busy(vdev, file))
		goto exit;
	err = vb2_read(vdev->queue, buf, count, ppos,
		       file->f_flags & O_NONBLOCK);
	if (vdev->queue->fileio)
		vdev->queue->owner = file->private_data;
exit:
	if (lock)
		mutex_unlock(lock);
	return err;
}
EXPORT_SYMBOL_GPL(vb2_fop_read);

unsigned int vb2_fop_poll(struct file *file, poll_table *wait)
{
	struct video_device *vdev = video_devdata(file);
	struct vb2_queue *q = vdev->queue;
	struct mutex *lock = q->lock ? q->lock : vdev->lock;
	unsigned res;
	void *fileio;

	/*
	 * If this helper doesn't know how to lock, then you shouldn't be using
	 * it but you should write your own.
	 */
	WARN_ON(!lock);

	if (lock && mutex_lock_interruptible(lock))
		return POLLERR;

	fileio = q->fileio;

	res = vb2_poll(vdev->queue, file, wait);

	/* If fileio was started, then we have a new queue owner. */
	if (!fileio && q->fileio)
		q->owner = file->private_data;
	if (lock)
		mutex_unlock(lock);
	return res;
}
EXPORT_SYMBOL_GPL(vb2_fop_poll);

#ifndef CONFIG_MMU
unsigned long vb2_fop_get_unmapped_area(struct file *file, unsigned long addr,
		unsigned long len, unsigned long pgoff, unsigned long flags)
{
	struct video_device *vdev = video_devdata(file);

	return vb2_get_unmapped_area(vdev->queue, addr, len, pgoff, flags);
}
EXPORT_SYMBOL_GPL(vb2_fop_get_unmapped_area);
#endif

/* vb2_ops helpers. Only use if vq->lock is non-NULL. */

void vb2_ops_wait_prepare(struct vb2_queue *vq)
{
	mutex_unlock(vq->lock);
}
EXPORT_SYMBOL_GPL(vb2_ops_wait_prepare);

void vb2_ops_wait_finish(struct vb2_queue *vq)
{
	mutex_lock(vq->lock);
}
EXPORT_SYMBOL_GPL(vb2_ops_wait_finish);

MODULE_DESCRIPTION("Driver helper framework for Video for Linux 2");
MODULE_AUTHOR("Pawel Osciak <pawel@osciak.com>, Marek Szyprowski");
MODULE_LICENSE("GPL");