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
1110
1111
1112
1113
1114
1115
1116
1117
1118
1119
1120
1121
1122
1123
1124
1125
1126
1127
1128
1129
1130
1131
1132
1133
1134
1135
1136
1137
1138
1139
1140
1141
1142
1143
1144
1145
1146
1147
1148
1149
1150
1151
1152
1153
1154
1155
1156
1157
1158
1159
1160
1161
1162
1163
1164
1165
1166
1167
1168
1169
1170
1171
1172
1173
1174
1175
1176
1177
1178
1179
1180
1181
1182
1183
1184
1185
1186
1187
1188
1189
1190
1191
1192
1193
1194
1195
1196
1197
1198
1199
1200
1201
1202
1203
1204
1205
1206
1207
1208
1209
1210
1211
1212
1213
1214
1215
1216
1217
1218
1219
1220
1221
1222
1223
1224
1225
1226
1227
1228
1229
1230
1231
1232
1233
1234
1235
1236
1237
1238
1239
1240
1241
1242
1243
1244
1245
1246
1247
1248
1249
1250
1251
1252
1253
1254
1255
1256
1257
1258
1259
1260
1261
1262
1263
1264
1265
1266
1267
1268
1269
1270
1271
1272
1273
1274
1275
1276
1277
1278
1279
1280
1281
1282
1283
1284
1285
1286
1287
1288
1289
1290
1291
1292
1293
1294
1295
1296
1297
1298
1299
1300
1301
1302
1303
1304
1305
1306
1307
1308
1309
1310
1311
1312
1313
1314
1315
|
// SPDX-License-Identifier: GPL-2.0-or-later
/*
* V4L2 controls framework uAPI implementation:
*
* Copyright (C) 2010-2021 Hans Verkuil <hverkuil-cisco@xs4all.nl>
*/
#define pr_fmt(fmt) "v4l2-ctrls: " fmt
#include <linux/export.h>
#include <linux/mm.h>
#include <linux/slab.h>
#include <media/v4l2-ctrls.h>
#include <media/v4l2-dev.h>
#include <media/v4l2-device.h>
#include <media/v4l2-event.h>
#include <media/v4l2-ioctl.h>
#include "v4l2-ctrls-priv.h"
/* Internal temporary helper struct, one for each v4l2_ext_control */
struct v4l2_ctrl_helper {
/* Pointer to the control reference of the master control */
struct v4l2_ctrl_ref *mref;
/* The control ref corresponding to the v4l2_ext_control ID field. */
struct v4l2_ctrl_ref *ref;
/*
* v4l2_ext_control index of the next control belonging to the
* same cluster, or 0 if there isn't any.
*/
u32 next;
};
/*
* Helper functions to copy control payload data from kernel space to
* user space and vice versa.
*/
/* Helper function: copy the given control value back to the caller */
static int ptr_to_user(struct v4l2_ext_control *c,
struct v4l2_ctrl *ctrl,
union v4l2_ctrl_ptr ptr)
{
u32 len;
if (ctrl->is_ptr && !ctrl->is_string)
return copy_to_user(c->ptr, ptr.p_const, c->size) ?
-EFAULT : 0;
switch (ctrl->type) {
case V4L2_CTRL_TYPE_STRING:
len = strlen(ptr.p_char);
if (c->size < len + 1) {
c->size = ctrl->elem_size;
return -ENOSPC;
}
return copy_to_user(c->string, ptr.p_char, len + 1) ?
-EFAULT : 0;
case V4L2_CTRL_TYPE_INTEGER64:
c->value64 = *ptr.p_s64;
break;
default:
c->value = *ptr.p_s32;
break;
}
return 0;
}
/* Helper function: copy the current control value back to the caller */
static int cur_to_user(struct v4l2_ext_control *c, struct v4l2_ctrl *ctrl)
{
return ptr_to_user(c, ctrl, ctrl->p_cur);
}
/* Helper function: copy the new control value back to the caller */
static int new_to_user(struct v4l2_ext_control *c,
struct v4l2_ctrl *ctrl)
{
return ptr_to_user(c, ctrl, ctrl->p_new);
}
/* Helper function: copy the request value back to the caller */
static int req_to_user(struct v4l2_ext_control *c,
struct v4l2_ctrl_ref *ref)
{
return ptr_to_user(c, ref->ctrl, ref->p_req);
}
/* Helper function: copy the initial control value back to the caller */
static int def_to_user(struct v4l2_ext_control *c, struct v4l2_ctrl *ctrl)
{
ctrl->type_ops->init(ctrl, 0, ctrl->p_new);
return ptr_to_user(c, ctrl, ctrl->p_new);
}
/* Helper function: copy the caller-provider value as the new control value */
static int user_to_new(struct v4l2_ext_control *c, struct v4l2_ctrl *ctrl)
{
int ret;
u32 size;
ctrl->is_new = 0;
if (ctrl->is_dyn_array &&
c->size > ctrl->p_array_alloc_elems * ctrl->elem_size) {
void *old = ctrl->p_array;
void *tmp = kvzalloc(2 * c->size, GFP_KERNEL);
if (!tmp)
return -ENOMEM;
memcpy(tmp, ctrl->p_new.p, ctrl->elems * ctrl->elem_size);
memcpy(tmp + c->size, ctrl->p_cur.p, ctrl->elems * ctrl->elem_size);
ctrl->p_new.p = tmp;
ctrl->p_cur.p = tmp + c->size;
ctrl->p_array = tmp;
ctrl->p_array_alloc_elems = c->size / ctrl->elem_size;
kvfree(old);
}
if (ctrl->is_ptr && !ctrl->is_string) {
unsigned int elems = c->size / ctrl->elem_size;
if (copy_from_user(ctrl->p_new.p, c->ptr, c->size))
return -EFAULT;
ctrl->is_new = 1;
if (ctrl->is_dyn_array)
ctrl->new_elems = elems;
else if (ctrl->is_array)
ctrl->type_ops->init(ctrl, elems, ctrl->p_new);
return 0;
}
switch (ctrl->type) {
case V4L2_CTRL_TYPE_INTEGER64:
*ctrl->p_new.p_s64 = c->value64;
break;
case V4L2_CTRL_TYPE_STRING:
size = c->size;
if (size == 0)
return -ERANGE;
if (size > ctrl->maximum + 1)
size = ctrl->maximum + 1;
ret = copy_from_user(ctrl->p_new.p_char, c->string, size) ? -EFAULT : 0;
if (!ret) {
char last = ctrl->p_new.p_char[size - 1];
ctrl->p_new.p_char[size - 1] = 0;
/*
* If the string was longer than ctrl->maximum,
* then return an error.
*/
if (strlen(ctrl->p_new.p_char) == ctrl->maximum && last)
return -ERANGE;
ctrl->is_new = 1;
}
return ret;
default:
*ctrl->p_new.p_s32 = c->value;
break;
}
ctrl->is_new = 1;
return 0;
}
/*
* VIDIOC_G/TRY/S_EXT_CTRLS implementation
*/
/*
* Some general notes on the atomic requirements of VIDIOC_G/TRY/S_EXT_CTRLS:
*
* It is not a fully atomic operation, just best-effort only. After all, if
* multiple controls have to be set through multiple i2c writes (for example)
* then some initial writes may succeed while others fail. Thus leaving the
* system in an inconsistent state. The question is how much effort you are
* willing to spend on trying to make something atomic that really isn't.
*
* From the point of view of an application the main requirement is that
* when you call VIDIOC_S_EXT_CTRLS and some values are invalid then an
* error should be returned without actually affecting any controls.
*
* If all the values are correct, then it is acceptable to just give up
* in case of low-level errors.
*
* It is important though that the application can tell when only a partial
* configuration was done. The way we do that is through the error_idx field
* of struct v4l2_ext_controls: if that is equal to the count field then no
* controls were affected. Otherwise all controls before that index were
* successful in performing their 'get' or 'set' operation, the control at
* the given index failed, and you don't know what happened with the controls
* after the failed one. Since if they were part of a control cluster they
* could have been successfully processed (if a cluster member was encountered
* at index < error_idx), they could have failed (if a cluster member was at
* error_idx), or they may not have been processed yet (if the first cluster
* member appeared after error_idx).
*
* It is all fairly theoretical, though. In practice all you can do is to
* bail out. If error_idx == count, then it is an application bug. If
* error_idx < count then it is only an application bug if the error code was
* EBUSY. That usually means that something started streaming just when you
* tried to set the controls. In all other cases it is a driver/hardware
* problem and all you can do is to retry or bail out.
*
* Note that these rules do not apply to VIDIOC_TRY_EXT_CTRLS: since that
* never modifies controls the error_idx is just set to whatever control
* has an invalid value.
*/
/*
* Prepare for the extended g/s/try functions.
* Find the controls in the control array and do some basic checks.
*/
static int prepare_ext_ctrls(struct v4l2_ctrl_handler *hdl,
struct v4l2_ext_controls *cs,
struct v4l2_ctrl_helper *helpers,
struct video_device *vdev,
bool get)
{
struct v4l2_ctrl_helper *h;
bool have_clusters = false;
u32 i;
for (i = 0, h = helpers; i < cs->count; i++, h++) {
struct v4l2_ext_control *c = &cs->controls[i];
struct v4l2_ctrl_ref *ref;
struct v4l2_ctrl *ctrl;
u32 id = c->id & V4L2_CTRL_ID_MASK;
cs->error_idx = i;
if (cs->which &&
cs->which != V4L2_CTRL_WHICH_DEF_VAL &&
cs->which != V4L2_CTRL_WHICH_REQUEST_VAL &&
V4L2_CTRL_ID2WHICH(id) != cs->which) {
dprintk(vdev,
"invalid which 0x%x or control id 0x%x\n",
cs->which, id);
return -EINVAL;
}
/*
* Old-style private controls are not allowed for
* extended controls.
*/
if (id >= V4L2_CID_PRIVATE_BASE) {
dprintk(vdev,
"old-style private controls not allowed\n");
return -EINVAL;
}
ref = find_ref_lock(hdl, id);
if (!ref) {
dprintk(vdev, "cannot find control id 0x%x\n", id);
return -EINVAL;
}
h->ref = ref;
ctrl = ref->ctrl;
if (ctrl->flags & V4L2_CTRL_FLAG_DISABLED) {
dprintk(vdev, "control id 0x%x is disabled\n", id);
return -EINVAL;
}
if (ctrl->cluster[0]->ncontrols > 1)
have_clusters = true;
if (ctrl->cluster[0] != ctrl)
ref = find_ref_lock(hdl, ctrl->cluster[0]->id);
if (ctrl->is_dyn_array) {
unsigned int max_size = ctrl->dims[0] * ctrl->elem_size;
unsigned int tot_size = ctrl->elem_size;
if (cs->which == V4L2_CTRL_WHICH_REQUEST_VAL)
tot_size *= ref->p_req_elems;
else
tot_size *= ctrl->elems;
c->size = ctrl->elem_size * (c->size / ctrl->elem_size);
if (get) {
if (c->size < tot_size) {
c->size = tot_size;
return -ENOSPC;
}
c->size = tot_size;
} else {
if (c->size > max_size) {
c->size = max_size;
return -ENOSPC;
}
if (!c->size)
return -EFAULT;
}
} else if (ctrl->is_ptr && !ctrl->is_string) {
unsigned int tot_size = ctrl->elems * ctrl->elem_size;
if (c->size < tot_size) {
/*
* In the get case the application first
* queries to obtain the size of the control.
*/
if (get) {
c->size = tot_size;
return -ENOSPC;
}
dprintk(vdev,
"pointer control id 0x%x size too small, %d bytes but %d bytes needed\n",
id, c->size, tot_size);
return -EFAULT;
}
c->size = tot_size;
}
/* Store the ref to the master control of the cluster */
h->mref = ref;
/*
* Initially set next to 0, meaning that there is no other
* control in this helper array belonging to the same
* cluster.
*/
h->next = 0;
}
/*
* We are done if there were no controls that belong to a multi-
* control cluster.
*/
if (!have_clusters)
return 0;
/*
* The code below figures out in O(n) time which controls in the list
* belong to the same cluster.
*/
/* This has to be done with the handler lock taken. */
mutex_lock(hdl->lock);
/* First zero the helper field in the master control references */
for (i = 0; i < cs->count; i++)
helpers[i].mref->helper = NULL;
for (i = 0, h = helpers; i < cs->count; i++, h++) {
struct v4l2_ctrl_ref *mref = h->mref;
/*
* If the mref->helper is set, then it points to an earlier
* helper that belongs to the same cluster.
*/
if (mref->helper) {
/*
* Set the next field of mref->helper to the current
* index: this means that the earlier helper now
* points to the next helper in the same cluster.
*/
mref->helper->next = i;
/*
* mref should be set only for the first helper in the
* cluster, clear the others.
*/
h->mref = NULL;
}
/* Point the mref helper to the current helper struct. */
mref->helper = h;
}
mutex_unlock(hdl->lock);
return 0;
}
/*
* Handles the corner case where cs->count == 0. It checks whether the
* specified control class exists. If that class ID is 0, then it checks
* whether there are any controls at all.
*/
static int class_check(struct v4l2_ctrl_handler *hdl, u32 which)
{
if (which == 0 || which == V4L2_CTRL_WHICH_DEF_VAL ||
which == V4L2_CTRL_WHICH_REQUEST_VAL)
return 0;
return find_ref_lock(hdl, which | 1) ? 0 : -EINVAL;
}
/*
* Get extended controls. Allocates the helpers array if needed.
*
* Note that v4l2_g_ext_ctrls_common() with 'which' set to
* V4L2_CTRL_WHICH_REQUEST_VAL is only called if the request was
* completed, and in that case p_req_valid is true for all controls.
*/
int v4l2_g_ext_ctrls_common(struct v4l2_ctrl_handler *hdl,
struct v4l2_ext_controls *cs,
struct video_device *vdev)
{
struct v4l2_ctrl_helper helper[4];
struct v4l2_ctrl_helper *helpers = helper;
int ret;
int i, j;
bool is_default, is_request;
is_default = (cs->which == V4L2_CTRL_WHICH_DEF_VAL);
is_request = (cs->which == V4L2_CTRL_WHICH_REQUEST_VAL);
cs->error_idx = cs->count;
cs->which = V4L2_CTRL_ID2WHICH(cs->which);
if (!hdl)
return -EINVAL;
if (cs->count == 0)
return class_check(hdl, cs->which);
if (cs->count > ARRAY_SIZE(helper)) {
helpers = kvmalloc_array(cs->count, sizeof(helper[0]),
GFP_KERNEL);
if (!helpers)
return -ENOMEM;
}
ret = prepare_ext_ctrls(hdl, cs, helpers, vdev, true);
cs->error_idx = cs->count;
for (i = 0; !ret && i < cs->count; i++)
if (helpers[i].ref->ctrl->flags & V4L2_CTRL_FLAG_WRITE_ONLY)
ret = -EACCES;
for (i = 0; !ret && i < cs->count; i++) {
struct v4l2_ctrl *master;
bool is_volatile = false;
u32 idx = i;
if (!helpers[i].mref)
continue;
master = helpers[i].mref->ctrl;
cs->error_idx = i;
v4l2_ctrl_lock(master);
/*
* g_volatile_ctrl will update the new control values.
* This makes no sense for V4L2_CTRL_WHICH_DEF_VAL and
* V4L2_CTRL_WHICH_REQUEST_VAL. In the case of requests
* it is v4l2_ctrl_request_complete() that copies the
* volatile controls at the time of request completion
* to the request, so you don't want to do that again.
*/
if (!is_default && !is_request &&
((master->flags & V4L2_CTRL_FLAG_VOLATILE) ||
(master->has_volatiles && !is_cur_manual(master)))) {
for (j = 0; j < master->ncontrols; j++)
cur_to_new(master->cluster[j]);
ret = call_op(master, g_volatile_ctrl);
is_volatile = true;
}
if (ret) {
v4l2_ctrl_unlock(master);
break;
}
/*
* Copy the default value (if is_default is true), the
* request value (if is_request is true and p_req is valid),
* the new volatile value (if is_volatile is true) or the
* current value.
*/
do {
struct v4l2_ctrl_ref *ref = helpers[idx].ref;
if (is_default)
ret = def_to_user(cs->controls + idx, ref->ctrl);
else if (is_request && ref->p_req_array_enomem)
ret = -ENOMEM;
else if (is_request && ref->p_req_valid)
ret = req_to_user(cs->controls + idx, ref);
else if (is_volatile)
ret = new_to_user(cs->controls + idx, ref->ctrl);
else
ret = cur_to_user(cs->controls + idx, ref->ctrl);
idx = helpers[idx].next;
} while (!ret && idx);
v4l2_ctrl_unlock(master);
}
if (cs->count > ARRAY_SIZE(helper))
kvfree(helpers);
return ret;
}
int v4l2_g_ext_ctrls(struct v4l2_ctrl_handler *hdl, struct video_device *vdev,
struct media_device *mdev, struct v4l2_ext_controls *cs)
{
if (cs->which == V4L2_CTRL_WHICH_REQUEST_VAL)
return v4l2_g_ext_ctrls_request(hdl, vdev, mdev, cs);
return v4l2_g_ext_ctrls_common(hdl, cs, vdev);
}
EXPORT_SYMBOL(v4l2_g_ext_ctrls);
/* Validate a new control */
static int validate_new(const struct v4l2_ctrl *ctrl, union v4l2_ctrl_ptr p_new)
{
return ctrl->type_ops->validate(ctrl, p_new);
}
/* Validate controls. */
static int validate_ctrls(struct v4l2_ext_controls *cs,
struct v4l2_ctrl_helper *helpers,
struct video_device *vdev,
bool set)
{
unsigned int i;
int ret = 0;
cs->error_idx = cs->count;
for (i = 0; i < cs->count; i++) {
struct v4l2_ctrl *ctrl = helpers[i].ref->ctrl;
union v4l2_ctrl_ptr p_new;
cs->error_idx = i;
if (ctrl->flags & V4L2_CTRL_FLAG_READ_ONLY) {
dprintk(vdev,
"control id 0x%x is read-only\n",
ctrl->id);
return -EACCES;
}
/*
* This test is also done in try_set_control_cluster() which
* is called in atomic context, so that has the final say,
* but it makes sense to do an up-front check as well. Once
* an error occurs in try_set_control_cluster() some other
* controls may have been set already and we want to do a
* best-effort to avoid that.
*/
if (set && (ctrl->flags & V4L2_CTRL_FLAG_GRABBED)) {
dprintk(vdev,
"control id 0x%x is grabbed, cannot set\n",
ctrl->id);
return -EBUSY;
}
/*
* Skip validation for now if the payload needs to be copied
* from userspace into kernelspace. We'll validate those later.
*/
if (ctrl->is_ptr)
continue;
if (ctrl->type == V4L2_CTRL_TYPE_INTEGER64)
p_new.p_s64 = &cs->controls[i].value64;
else
p_new.p_s32 = &cs->controls[i].value;
ret = validate_new(ctrl, p_new);
if (ret)
return ret;
}
return 0;
}
/* Try or try-and-set controls */
int try_set_ext_ctrls_common(struct v4l2_fh *fh,
struct v4l2_ctrl_handler *hdl,
struct v4l2_ext_controls *cs,
struct video_device *vdev, bool set)
{
struct v4l2_ctrl_helper helper[4];
struct v4l2_ctrl_helper *helpers = helper;
unsigned int i, j;
int ret;
cs->error_idx = cs->count;
/* Default value cannot be changed */
if (cs->which == V4L2_CTRL_WHICH_DEF_VAL) {
dprintk(vdev, "%s: cannot change default value\n",
video_device_node_name(vdev));
return -EINVAL;
}
cs->which = V4L2_CTRL_ID2WHICH(cs->which);
if (!hdl) {
dprintk(vdev, "%s: invalid null control handler\n",
video_device_node_name(vdev));
return -EINVAL;
}
if (cs->count == 0)
return class_check(hdl, cs->which);
if (cs->count > ARRAY_SIZE(helper)) {
helpers = kvmalloc_array(cs->count, sizeof(helper[0]),
GFP_KERNEL);
if (!helpers)
return -ENOMEM;
}
ret = prepare_ext_ctrls(hdl, cs, helpers, vdev, false);
if (!ret)
ret = validate_ctrls(cs, helpers, vdev, set);
if (ret && set)
cs->error_idx = cs->count;
for (i = 0; !ret && i < cs->count; i++) {
struct v4l2_ctrl *master;
u32 idx = i;
if (!helpers[i].mref)
continue;
cs->error_idx = i;
master = helpers[i].mref->ctrl;
v4l2_ctrl_lock(master);
/* Reset the 'is_new' flags of the cluster */
for (j = 0; j < master->ncontrols; j++)
if (master->cluster[j])
master->cluster[j]->is_new = 0;
/*
* For volatile autoclusters that are currently in auto mode
* we need to discover if it will be set to manual mode.
* If so, then we have to copy the current volatile values
* first since those will become the new manual values (which
* may be overwritten by explicit new values from this set
* of controls).
*/
if (master->is_auto && master->has_volatiles &&
!is_cur_manual(master)) {
/* Pick an initial non-manual value */
s32 new_auto_val = master->manual_mode_value + 1;
u32 tmp_idx = idx;
do {
/*
* Check if the auto control is part of the
* list, and remember the new value.
*/
if (helpers[tmp_idx].ref->ctrl == master)
new_auto_val = cs->controls[tmp_idx].value;
tmp_idx = helpers[tmp_idx].next;
} while (tmp_idx);
/*
* If the new value == the manual value, then copy
* the current volatile values.
*/
if (new_auto_val == master->manual_mode_value)
update_from_auto_cluster(master);
}
/*
* Copy the new caller-supplied control values.
* user_to_new() sets 'is_new' to 1.
*/
do {
struct v4l2_ctrl *ctrl = helpers[idx].ref->ctrl;
ret = user_to_new(cs->controls + idx, ctrl);
if (!ret && ctrl->is_ptr) {
ret = validate_new(ctrl, ctrl->p_new);
if (ret)
dprintk(vdev,
"failed to validate control %s (%d)\n",
v4l2_ctrl_get_name(ctrl->id), ret);
}
idx = helpers[idx].next;
} while (!ret && idx);
if (!ret)
ret = try_or_set_cluster(fh, master,
!hdl->req_obj.req && set, 0);
if (!ret && hdl->req_obj.req && set) {
for (j = 0; j < master->ncontrols; j++) {
struct v4l2_ctrl_ref *ref =
find_ref(hdl, master->cluster[j]->id);
new_to_req(ref);
}
}
/* Copy the new values back to userspace. */
if (!ret) {
idx = i;
do {
ret = new_to_user(cs->controls + idx,
helpers[idx].ref->ctrl);
idx = helpers[idx].next;
} while (!ret && idx);
}
v4l2_ctrl_unlock(master);
}
if (cs->count > ARRAY_SIZE(helper))
kvfree(helpers);
return ret;
}
static int try_set_ext_ctrls(struct v4l2_fh *fh,
struct v4l2_ctrl_handler *hdl,
struct video_device *vdev,
struct media_device *mdev,
struct v4l2_ext_controls *cs, bool set)
{
int ret;
if (cs->which == V4L2_CTRL_WHICH_REQUEST_VAL)
return try_set_ext_ctrls_request(fh, hdl, vdev, mdev, cs, set);
ret = try_set_ext_ctrls_common(fh, hdl, cs, vdev, set);
if (ret)
dprintk(vdev,
"%s: try_set_ext_ctrls_common failed (%d)\n",
video_device_node_name(vdev), ret);
return ret;
}
int v4l2_try_ext_ctrls(struct v4l2_ctrl_handler *hdl,
struct video_device *vdev,
struct media_device *mdev,
struct v4l2_ext_controls *cs)
{
return try_set_ext_ctrls(NULL, hdl, vdev, mdev, cs, false);
}
EXPORT_SYMBOL(v4l2_try_ext_ctrls);
int v4l2_s_ext_ctrls(struct v4l2_fh *fh,
struct v4l2_ctrl_handler *hdl,
struct video_device *vdev,
struct media_device *mdev,
struct v4l2_ext_controls *cs)
{
return try_set_ext_ctrls(fh, hdl, vdev, mdev, cs, true);
}
EXPORT_SYMBOL(v4l2_s_ext_ctrls);
/*
* VIDIOC_G/S_CTRL implementation
*/
/* Helper function to get a single control */
static int get_ctrl(struct v4l2_ctrl *ctrl, struct v4l2_ext_control *c)
{
struct v4l2_ctrl *master = ctrl->cluster[0];
int ret = 0;
int i;
/* Compound controls are not supported. The new_to_user() and
* cur_to_user() calls below would need to be modified not to access
* userspace memory when called from get_ctrl().
*/
if (!ctrl->is_int && ctrl->type != V4L2_CTRL_TYPE_INTEGER64)
return -EINVAL;
if (ctrl->flags & V4L2_CTRL_FLAG_WRITE_ONLY)
return -EACCES;
v4l2_ctrl_lock(master);
/* g_volatile_ctrl will update the current control values */
if (ctrl->flags & V4L2_CTRL_FLAG_VOLATILE) {
for (i = 0; i < master->ncontrols; i++)
cur_to_new(master->cluster[i]);
ret = call_op(master, g_volatile_ctrl);
if (!ret)
ret = new_to_user(c, ctrl);
} else {
ret = cur_to_user(c, ctrl);
}
v4l2_ctrl_unlock(master);
return ret;
}
int v4l2_g_ctrl(struct v4l2_ctrl_handler *hdl, struct v4l2_control *control)
{
struct v4l2_ctrl *ctrl = v4l2_ctrl_find(hdl, control->id);
struct v4l2_ext_control c;
int ret;
if (!ctrl || !ctrl->is_int)
return -EINVAL;
ret = get_ctrl(ctrl, &c);
if (!ret)
control->value = c.value;
return ret;
}
EXPORT_SYMBOL(v4l2_g_ctrl);
/* Helper function for VIDIOC_S_CTRL compatibility */
static int set_ctrl(struct v4l2_fh *fh, struct v4l2_ctrl *ctrl, u32 ch_flags)
{
struct v4l2_ctrl *master = ctrl->cluster[0];
int ret;
int i;
/* Reset the 'is_new' flags of the cluster */
for (i = 0; i < master->ncontrols; i++)
if (master->cluster[i])
master->cluster[i]->is_new = 0;
ret = validate_new(ctrl, ctrl->p_new);
if (ret)
return ret;
/*
* For autoclusters with volatiles that are switched from auto to
* manual mode we have to update the current volatile values since
* those will become the initial manual values after such a switch.
*/
if (master->is_auto && master->has_volatiles && ctrl == master &&
!is_cur_manual(master) && ctrl->val == master->manual_mode_value)
update_from_auto_cluster(master);
ctrl->is_new = 1;
return try_or_set_cluster(fh, master, true, ch_flags);
}
/* Helper function for VIDIOC_S_CTRL compatibility */
static int set_ctrl_lock(struct v4l2_fh *fh, struct v4l2_ctrl *ctrl,
struct v4l2_ext_control *c)
{
int ret;
v4l2_ctrl_lock(ctrl);
ret = user_to_new(c, ctrl);
if (!ret)
ret = set_ctrl(fh, ctrl, 0);
if (!ret)
ret = cur_to_user(c, ctrl);
v4l2_ctrl_unlock(ctrl);
return ret;
}
int v4l2_s_ctrl(struct v4l2_fh *fh, struct v4l2_ctrl_handler *hdl,
struct v4l2_control *control)
{
struct v4l2_ctrl *ctrl = v4l2_ctrl_find(hdl, control->id);
struct v4l2_ext_control c = { control->id };
int ret;
if (!ctrl || !ctrl->is_int)
return -EINVAL;
if (ctrl->flags & V4L2_CTRL_FLAG_READ_ONLY)
return -EACCES;
c.value = control->value;
ret = set_ctrl_lock(fh, ctrl, &c);
control->value = c.value;
return ret;
}
EXPORT_SYMBOL(v4l2_s_ctrl);
/*
* Helper functions for drivers to get/set controls.
*/
s32 v4l2_ctrl_g_ctrl(struct v4l2_ctrl *ctrl)
{
struct v4l2_ext_control c;
/* It's a driver bug if this happens. */
if (WARN_ON(!ctrl->is_int))
return 0;
c.value = 0;
get_ctrl(ctrl, &c);
return c.value;
}
EXPORT_SYMBOL(v4l2_ctrl_g_ctrl);
s64 v4l2_ctrl_g_ctrl_int64(struct v4l2_ctrl *ctrl)
{
struct v4l2_ext_control c;
/* It's a driver bug if this happens. */
if (WARN_ON(ctrl->is_ptr || ctrl->type != V4L2_CTRL_TYPE_INTEGER64))
return 0;
c.value64 = 0;
get_ctrl(ctrl, &c);
return c.value64;
}
EXPORT_SYMBOL(v4l2_ctrl_g_ctrl_int64);
int __v4l2_ctrl_s_ctrl(struct v4l2_ctrl *ctrl, s32 val)
{
lockdep_assert_held(ctrl->handler->lock);
/* It's a driver bug if this happens. */
if (WARN_ON(!ctrl->is_int))
return -EINVAL;
ctrl->val = val;
return set_ctrl(NULL, ctrl, 0);
}
EXPORT_SYMBOL(__v4l2_ctrl_s_ctrl);
int __v4l2_ctrl_s_ctrl_int64(struct v4l2_ctrl *ctrl, s64 val)
{
lockdep_assert_held(ctrl->handler->lock);
/* It's a driver bug if this happens. */
if (WARN_ON(ctrl->is_ptr || ctrl->type != V4L2_CTRL_TYPE_INTEGER64))
return -EINVAL;
*ctrl->p_new.p_s64 = val;
return set_ctrl(NULL, ctrl, 0);
}
EXPORT_SYMBOL(__v4l2_ctrl_s_ctrl_int64);
int __v4l2_ctrl_s_ctrl_string(struct v4l2_ctrl *ctrl, const char *s)
{
lockdep_assert_held(ctrl->handler->lock);
/* It's a driver bug if this happens. */
if (WARN_ON(ctrl->type != V4L2_CTRL_TYPE_STRING))
return -EINVAL;
strscpy(ctrl->p_new.p_char, s, ctrl->maximum + 1);
return set_ctrl(NULL, ctrl, 0);
}
EXPORT_SYMBOL(__v4l2_ctrl_s_ctrl_string);
int __v4l2_ctrl_s_ctrl_compound(struct v4l2_ctrl *ctrl,
enum v4l2_ctrl_type type, const void *p)
{
lockdep_assert_held(ctrl->handler->lock);
/* It's a driver bug if this happens. */
if (WARN_ON(ctrl->type != type))
return -EINVAL;
/* Setting dynamic arrays is not (yet?) supported. */
if (WARN_ON(ctrl->is_dyn_array))
return -EINVAL;
memcpy(ctrl->p_new.p, p, ctrl->elems * ctrl->elem_size);
return set_ctrl(NULL, ctrl, 0);
}
EXPORT_SYMBOL(__v4l2_ctrl_s_ctrl_compound);
/*
* Modify the range of a control.
*/
int __v4l2_ctrl_modify_range(struct v4l2_ctrl *ctrl,
s64 min, s64 max, u64 step, s64 def)
{
bool value_changed;
bool range_changed = false;
int ret;
lockdep_assert_held(ctrl->handler->lock);
switch (ctrl->type) {
case V4L2_CTRL_TYPE_INTEGER:
case V4L2_CTRL_TYPE_INTEGER64:
case V4L2_CTRL_TYPE_BOOLEAN:
case V4L2_CTRL_TYPE_MENU:
case V4L2_CTRL_TYPE_INTEGER_MENU:
case V4L2_CTRL_TYPE_BITMASK:
case V4L2_CTRL_TYPE_U8:
case V4L2_CTRL_TYPE_U16:
case V4L2_CTRL_TYPE_U32:
if (ctrl->is_array)
return -EINVAL;
ret = check_range(ctrl->type, min, max, step, def);
if (ret)
return ret;
break;
default:
return -EINVAL;
}
if (ctrl->minimum != min || ctrl->maximum != max ||
ctrl->step != step || ctrl->default_value != def) {
range_changed = true;
ctrl->minimum = min;
ctrl->maximum = max;
ctrl->step = step;
ctrl->default_value = def;
}
cur_to_new(ctrl);
if (validate_new(ctrl, ctrl->p_new)) {
if (ctrl->type == V4L2_CTRL_TYPE_INTEGER64)
*ctrl->p_new.p_s64 = def;
else
*ctrl->p_new.p_s32 = def;
}
if (ctrl->type == V4L2_CTRL_TYPE_INTEGER64)
value_changed = *ctrl->p_new.p_s64 != *ctrl->p_cur.p_s64;
else
value_changed = *ctrl->p_new.p_s32 != *ctrl->p_cur.p_s32;
if (value_changed)
ret = set_ctrl(NULL, ctrl, V4L2_EVENT_CTRL_CH_RANGE);
else if (range_changed)
send_event(NULL, ctrl, V4L2_EVENT_CTRL_CH_RANGE);
return ret;
}
EXPORT_SYMBOL(__v4l2_ctrl_modify_range);
int __v4l2_ctrl_modify_dimensions(struct v4l2_ctrl *ctrl,
u32 dims[V4L2_CTRL_MAX_DIMS])
{
unsigned int elems = 1;
unsigned int i;
void *p_array;
lockdep_assert_held(ctrl->handler->lock);
if (!ctrl->is_array || ctrl->is_dyn_array)
return -EINVAL;
for (i = 0; i < ctrl->nr_of_dims; i++)
elems *= dims[i];
if (elems == 0)
return -EINVAL;
p_array = kvzalloc(2 * elems * ctrl->elem_size, GFP_KERNEL);
if (!p_array)
return -ENOMEM;
kvfree(ctrl->p_array);
ctrl->p_array_alloc_elems = elems;
ctrl->elems = elems;
ctrl->new_elems = elems;
ctrl->p_array = p_array;
ctrl->p_new.p = p_array;
ctrl->p_cur.p = p_array + elems * ctrl->elem_size;
for (i = 0; i < ctrl->nr_of_dims; i++)
ctrl->dims[i] = dims[i];
ctrl->type_ops->init(ctrl, 0, ctrl->p_cur);
cur_to_new(ctrl);
send_event(NULL, ctrl, V4L2_EVENT_CTRL_CH_VALUE |
V4L2_EVENT_CTRL_CH_DIMENSIONS);
return 0;
}
EXPORT_SYMBOL(__v4l2_ctrl_modify_dimensions);
/* Implement VIDIOC_QUERY_EXT_CTRL */
int v4l2_query_ext_ctrl(struct v4l2_ctrl_handler *hdl, struct v4l2_query_ext_ctrl *qc)
{
const unsigned int next_flags = V4L2_CTRL_FLAG_NEXT_CTRL | V4L2_CTRL_FLAG_NEXT_COMPOUND;
u32 id = qc->id & V4L2_CTRL_ID_MASK;
struct v4l2_ctrl_ref *ref;
struct v4l2_ctrl *ctrl;
if (!hdl)
return -EINVAL;
mutex_lock(hdl->lock);
/* Try to find it */
ref = find_ref(hdl, id);
if ((qc->id & next_flags) && !list_empty(&hdl->ctrl_refs)) {
bool is_compound;
/* Match any control that is not hidden */
unsigned int mask = 1;
bool match = false;
if ((qc->id & next_flags) == V4L2_CTRL_FLAG_NEXT_COMPOUND) {
/* Match any hidden control */
match = true;
} else if ((qc->id & next_flags) == next_flags) {
/* Match any control, compound or not */
mask = 0;
}
/* Find the next control with ID > qc->id */
/* Did we reach the end of the control list? */
if (id >= node2id(hdl->ctrl_refs.prev)) {
ref = NULL; /* Yes, so there is no next control */
} else if (ref) {
struct v4l2_ctrl_ref *pos = ref;
/*
* We found a control with the given ID, so just get
* the next valid one in the list.
*/
ref = NULL;
list_for_each_entry_continue(pos, &hdl->ctrl_refs, node) {
is_compound = pos->ctrl->is_array ||
pos->ctrl->type >= V4L2_CTRL_COMPOUND_TYPES;
if (id < pos->ctrl->id &&
(is_compound & mask) == match) {
ref = pos;
break;
}
}
} else {
struct v4l2_ctrl_ref *pos;
/*
* No control with the given ID exists, so start
* searching for the next largest ID. We know there
* is one, otherwise the first 'if' above would have
* been true.
*/
list_for_each_entry(pos, &hdl->ctrl_refs, node) {
is_compound = pos->ctrl->is_array ||
pos->ctrl->type >= V4L2_CTRL_COMPOUND_TYPES;
if (id < pos->ctrl->id &&
(is_compound & mask) == match) {
ref = pos;
break;
}
}
}
}
mutex_unlock(hdl->lock);
if (!ref)
return -EINVAL;
ctrl = ref->ctrl;
memset(qc, 0, sizeof(*qc));
if (id >= V4L2_CID_PRIVATE_BASE)
qc->id = id;
else
qc->id = ctrl->id;
strscpy(qc->name, ctrl->name, sizeof(qc->name));
qc->flags = user_flags(ctrl);
qc->type = ctrl->type;
qc->elem_size = ctrl->elem_size;
qc->elems = ctrl->elems;
qc->nr_of_dims = ctrl->nr_of_dims;
memcpy(qc->dims, ctrl->dims, qc->nr_of_dims * sizeof(qc->dims[0]));
qc->minimum = ctrl->minimum;
qc->maximum = ctrl->maximum;
qc->default_value = ctrl->default_value;
if (ctrl->type == V4L2_CTRL_TYPE_MENU ||
ctrl->type == V4L2_CTRL_TYPE_INTEGER_MENU)
qc->step = 1;
else
qc->step = ctrl->step;
return 0;
}
EXPORT_SYMBOL(v4l2_query_ext_ctrl);
/* Implement VIDIOC_QUERYCTRL */
int v4l2_queryctrl(struct v4l2_ctrl_handler *hdl, struct v4l2_queryctrl *qc)
{
struct v4l2_query_ext_ctrl qec = { qc->id };
int rc;
rc = v4l2_query_ext_ctrl(hdl, &qec);
if (rc)
return rc;
qc->id = qec.id;
qc->type = qec.type;
qc->flags = qec.flags;
strscpy(qc->name, qec.name, sizeof(qc->name));
switch (qc->type) {
case V4L2_CTRL_TYPE_INTEGER:
case V4L2_CTRL_TYPE_BOOLEAN:
case V4L2_CTRL_TYPE_MENU:
case V4L2_CTRL_TYPE_INTEGER_MENU:
case V4L2_CTRL_TYPE_STRING:
case V4L2_CTRL_TYPE_BITMASK:
qc->minimum = qec.minimum;
qc->maximum = qec.maximum;
qc->step = qec.step;
qc->default_value = qec.default_value;
break;
default:
qc->minimum = 0;
qc->maximum = 0;
qc->step = 0;
qc->default_value = 0;
break;
}
return 0;
}
EXPORT_SYMBOL(v4l2_queryctrl);
/* Implement VIDIOC_QUERYMENU */
int v4l2_querymenu(struct v4l2_ctrl_handler *hdl, struct v4l2_querymenu *qm)
{
struct v4l2_ctrl *ctrl;
u32 i = qm->index;
ctrl = v4l2_ctrl_find(hdl, qm->id);
if (!ctrl)
return -EINVAL;
qm->reserved = 0;
/* Sanity checks */
switch (ctrl->type) {
case V4L2_CTRL_TYPE_MENU:
if (!ctrl->qmenu)
return -EINVAL;
break;
case V4L2_CTRL_TYPE_INTEGER_MENU:
if (!ctrl->qmenu_int)
return -EINVAL;
break;
default:
return -EINVAL;
}
if (i < ctrl->minimum || i > ctrl->maximum)
return -EINVAL;
/* Use mask to see if this menu item should be skipped */
if (i < BITS_PER_LONG_LONG && (ctrl->menu_skip_mask & BIT_ULL(i)))
return -EINVAL;
/* Empty menu items should also be skipped */
if (ctrl->type == V4L2_CTRL_TYPE_MENU) {
if (!ctrl->qmenu[i] || ctrl->qmenu[i][0] == '\0')
return -EINVAL;
strscpy(qm->name, ctrl->qmenu[i], sizeof(qm->name));
} else {
qm->value = ctrl->qmenu_int[i];
}
return 0;
}
EXPORT_SYMBOL(v4l2_querymenu);
/*
* VIDIOC_LOG_STATUS helpers
*/
int v4l2_ctrl_log_status(struct file *file, void *fh)
{
struct video_device *vfd = video_devdata(file);
struct v4l2_fh *vfh = file->private_data;
if (test_bit(V4L2_FL_USES_V4L2_FH, &vfd->flags) && vfd->v4l2_dev)
v4l2_ctrl_handler_log_status(vfh->ctrl_handler,
vfd->v4l2_dev->name);
return 0;
}
EXPORT_SYMBOL(v4l2_ctrl_log_status);
int v4l2_ctrl_subdev_log_status(struct v4l2_subdev *sd)
{
v4l2_ctrl_handler_log_status(sd->ctrl_handler, sd->name);
return 0;
}
EXPORT_SYMBOL(v4l2_ctrl_subdev_log_status);
/*
* VIDIOC_(UN)SUBSCRIBE_EVENT implementation
*/
static int v4l2_ctrl_add_event(struct v4l2_subscribed_event *sev,
unsigned int elems)
{
struct v4l2_ctrl *ctrl = v4l2_ctrl_find(sev->fh->ctrl_handler, sev->id);
if (!ctrl)
return -EINVAL;
v4l2_ctrl_lock(ctrl);
list_add_tail(&sev->node, &ctrl->ev_subs);
if (ctrl->type != V4L2_CTRL_TYPE_CTRL_CLASS &&
(sev->flags & V4L2_EVENT_SUB_FL_SEND_INITIAL))
send_initial_event(sev->fh, ctrl);
v4l2_ctrl_unlock(ctrl);
return 0;
}
static void v4l2_ctrl_del_event(struct v4l2_subscribed_event *sev)
{
struct v4l2_ctrl *ctrl = v4l2_ctrl_find(sev->fh->ctrl_handler, sev->id);
if (!ctrl)
return;
v4l2_ctrl_lock(ctrl);
list_del(&sev->node);
v4l2_ctrl_unlock(ctrl);
}
void v4l2_ctrl_replace(struct v4l2_event *old, const struct v4l2_event *new)
{
u32 old_changes = old->u.ctrl.changes;
old->u.ctrl = new->u.ctrl;
old->u.ctrl.changes |= old_changes;
}
EXPORT_SYMBOL(v4l2_ctrl_replace);
void v4l2_ctrl_merge(const struct v4l2_event *old, struct v4l2_event *new)
{
new->u.ctrl.changes |= old->u.ctrl.changes;
}
EXPORT_SYMBOL(v4l2_ctrl_merge);
const struct v4l2_subscribed_event_ops v4l2_ctrl_sub_ev_ops = {
.add = v4l2_ctrl_add_event,
.del = v4l2_ctrl_del_event,
.replace = v4l2_ctrl_replace,
.merge = v4l2_ctrl_merge,
};
EXPORT_SYMBOL(v4l2_ctrl_sub_ev_ops);
int v4l2_ctrl_subscribe_event(struct v4l2_fh *fh,
const struct v4l2_event_subscription *sub)
{
if (sub->type == V4L2_EVENT_CTRL)
return v4l2_event_subscribe(fh, sub, 0, &v4l2_ctrl_sub_ev_ops);
return -EINVAL;
}
EXPORT_SYMBOL(v4l2_ctrl_subscribe_event);
int v4l2_ctrl_subdev_subscribe_event(struct v4l2_subdev *sd, struct v4l2_fh *fh,
struct v4l2_event_subscription *sub)
{
if (!sd->ctrl_handler)
return -EINVAL;
return v4l2_ctrl_subscribe_event(fh, sub);
}
EXPORT_SYMBOL(v4l2_ctrl_subdev_subscribe_event);
/*
* poll helper
*/
__poll_t v4l2_ctrl_poll(struct file *file, struct poll_table_struct *wait)
{
struct v4l2_fh *fh = file->private_data;
poll_wait(file, &fh->wait, wait);
if (v4l2_event_pending(fh))
return EPOLLPRI;
return 0;
}
EXPORT_SYMBOL(v4l2_ctrl_poll);
|