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
|
/*
* uvc_video.c -- USB Video Class driver - Video handling
*
* Copyright (C) 2005-2010
* Laurent Pinchart (laurent.pinchart@ideasonboard.com)
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
*/
#include <linux/kernel.h>
#include <linux/list.h>
#include <linux/module.h>
#include <linux/slab.h>
#include <linux/usb.h>
#include <linux/videodev2.h>
#include <linux/vmalloc.h>
#include <linux/wait.h>
#include <asm/atomic.h>
#include <asm/unaligned.h>
#include <media/v4l2-common.h>
#include "uvcvideo.h"
/* ------------------------------------------------------------------------
* UVC Controls
*/
static int __uvc_query_ctrl(struct uvc_device *dev, __u8 query, __u8 unit,
__u8 intfnum, __u8 cs, void *data, __u16 size,
int timeout)
{
__u8 type = USB_TYPE_CLASS | USB_RECIP_INTERFACE;
unsigned int pipe;
pipe = (query & 0x80) ? usb_rcvctrlpipe(dev->udev, 0)
: usb_sndctrlpipe(dev->udev, 0);
type |= (query & 0x80) ? USB_DIR_IN : USB_DIR_OUT;
return usb_control_msg(dev->udev, pipe, query, type, cs << 8,
unit << 8 | intfnum, data, size, timeout);
}
static const char *uvc_query_name(__u8 query)
{
switch (query) {
case UVC_SET_CUR:
return "SET_CUR";
case UVC_GET_CUR:
return "GET_CUR";
case UVC_GET_MIN:
return "GET_MIN";
case UVC_GET_MAX:
return "GET_MAX";
case UVC_GET_RES:
return "GET_RES";
case UVC_GET_LEN:
return "GET_LEN";
case UVC_GET_INFO:
return "GET_INFO";
case UVC_GET_DEF:
return "GET_DEF";
default:
return "<invalid>";
}
}
int uvc_query_ctrl(struct uvc_device *dev, __u8 query, __u8 unit,
__u8 intfnum, __u8 cs, void *data, __u16 size)
{
int ret;
ret = __uvc_query_ctrl(dev, query, unit, intfnum, cs, data, size,
UVC_CTRL_CONTROL_TIMEOUT);
if (ret != size) {
uvc_printk(KERN_ERR, "Failed to query (%s) UVC control %u on "
"unit %u: %d (exp. %u).\n", uvc_query_name(query), cs,
unit, ret, size);
return -EIO;
}
return 0;
}
static void uvc_fixup_video_ctrl(struct uvc_streaming *stream,
struct uvc_streaming_control *ctrl)
{
struct uvc_format *format = NULL;
struct uvc_frame *frame = NULL;
unsigned int i;
for (i = 0; i < stream->nformats; ++i) {
if (stream->format[i].index == ctrl->bFormatIndex) {
format = &stream->format[i];
break;
}
}
if (format == NULL)
return;
for (i = 0; i < format->nframes; ++i) {
if (format->frame[i].bFrameIndex == ctrl->bFrameIndex) {
frame = &format->frame[i];
break;
}
}
if (frame == NULL)
return;
if (!(format->flags & UVC_FMT_FLAG_COMPRESSED) ||
(ctrl->dwMaxVideoFrameSize == 0 &&
stream->dev->uvc_version < 0x0110))
ctrl->dwMaxVideoFrameSize =
frame->dwMaxVideoFrameBufferSize;
if (!(format->flags & UVC_FMT_FLAG_COMPRESSED) &&
stream->dev->quirks & UVC_QUIRK_FIX_BANDWIDTH &&
stream->intf->num_altsetting > 1) {
u32 interval;
u32 bandwidth;
interval = (ctrl->dwFrameInterval > 100000)
? ctrl->dwFrameInterval
: frame->dwFrameInterval[0];
/* Compute a bandwidth estimation by multiplying the frame
* size by the number of video frames per second, divide the
* result by the number of USB frames (or micro-frames for
* high-speed devices) per second and add the UVC header size
* (assumed to be 12 bytes long).
*/
bandwidth = frame->wWidth * frame->wHeight / 8 * format->bpp;
bandwidth *= 10000000 / interval + 1;
bandwidth /= 1000;
if (stream->dev->udev->speed == USB_SPEED_HIGH)
bandwidth /= 8;
bandwidth += 12;
/* The bandwidth estimate is too low for many cameras. Don't use
* maximum packet sizes lower than 1024 bytes to try and work
* around the problem. According to measurements done on two
* different camera models, the value is high enough to get most
* resolutions working while not preventing two simultaneous
* VGA streams at 15 fps.
*/
bandwidth = max_t(u32, bandwidth, 1024);
ctrl->dwMaxPayloadTransferSize = bandwidth;
}
}
static int uvc_get_video_ctrl(struct uvc_streaming *stream,
struct uvc_streaming_control *ctrl, int probe, __u8 query)
{
__u8 *data;
__u16 size;
int ret;
size = stream->dev->uvc_version >= 0x0110 ? 34 : 26;
if ((stream->dev->quirks & UVC_QUIRK_PROBE_DEF) &&
query == UVC_GET_DEF)
return -EIO;
data = kmalloc(size, GFP_KERNEL);
if (data == NULL)
return -ENOMEM;
ret = __uvc_query_ctrl(stream->dev, query, 0, stream->intfnum,
probe ? UVC_VS_PROBE_CONTROL : UVC_VS_COMMIT_CONTROL, data,
size, uvc_timeout_param);
if ((query == UVC_GET_MIN || query == UVC_GET_MAX) && ret == 2) {
/* Some cameras, mostly based on Bison Electronics chipsets,
* answer a GET_MIN or GET_MAX request with the wCompQuality
* field only.
*/
uvc_warn_once(stream->dev, UVC_WARN_MINMAX, "UVC non "
"compliance - GET_MIN/MAX(PROBE) incorrectly "
"supported. Enabling workaround.\n");
memset(ctrl, 0, sizeof *ctrl);
ctrl->wCompQuality = le16_to_cpup((__le16 *)data);
ret = 0;
goto out;
} else if (query == UVC_GET_DEF && probe == 1 && ret != size) {
/* Many cameras don't support the GET_DEF request on their
* video probe control. Warn once and return, the caller will
* fall back to GET_CUR.
*/
uvc_warn_once(stream->dev, UVC_WARN_PROBE_DEF, "UVC non "
"compliance - GET_DEF(PROBE) not supported. "
"Enabling workaround.\n");
ret = -EIO;
goto out;
} else if (ret != size) {
uvc_printk(KERN_ERR, "Failed to query (%u) UVC %s control : "
"%d (exp. %u).\n", query, probe ? "probe" : "commit",
ret, size);
ret = -EIO;
goto out;
}
ctrl->bmHint = le16_to_cpup((__le16 *)&data[0]);
ctrl->bFormatIndex = data[2];
ctrl->bFrameIndex = data[3];
ctrl->dwFrameInterval = le32_to_cpup((__le32 *)&data[4]);
ctrl->wKeyFrameRate = le16_to_cpup((__le16 *)&data[8]);
ctrl->wPFrameRate = le16_to_cpup((__le16 *)&data[10]);
ctrl->wCompQuality = le16_to_cpup((__le16 *)&data[12]);
ctrl->wCompWindowSize = le16_to_cpup((__le16 *)&data[14]);
ctrl->wDelay = le16_to_cpup((__le16 *)&data[16]);
ctrl->dwMaxVideoFrameSize = get_unaligned_le32(&data[18]);
ctrl->dwMaxPayloadTransferSize = get_unaligned_le32(&data[22]);
if (size == 34) {
ctrl->dwClockFrequency = get_unaligned_le32(&data[26]);
ctrl->bmFramingInfo = data[30];
ctrl->bPreferedVersion = data[31];
ctrl->bMinVersion = data[32];
ctrl->bMaxVersion = data[33];
} else {
ctrl->dwClockFrequency = stream->dev->clock_frequency;
ctrl->bmFramingInfo = 0;
ctrl->bPreferedVersion = 0;
ctrl->bMinVersion = 0;
ctrl->bMaxVersion = 0;
}
/* Some broken devices return null or wrong dwMaxVideoFrameSize and
* dwMaxPayloadTransferSize fields. Try to get the value from the
* format and frame descriptors.
*/
uvc_fixup_video_ctrl(stream, ctrl);
ret = 0;
out:
kfree(data);
return ret;
}
static int uvc_set_video_ctrl(struct uvc_streaming *stream,
struct uvc_streaming_control *ctrl, int probe)
{
__u8 *data;
__u16 size;
int ret;
size = stream->dev->uvc_version >= 0x0110 ? 34 : 26;
data = kzalloc(size, GFP_KERNEL);
if (data == NULL)
return -ENOMEM;
*(__le16 *)&data[0] = cpu_to_le16(ctrl->bmHint);
data[2] = ctrl->bFormatIndex;
data[3] = ctrl->bFrameIndex;
*(__le32 *)&data[4] = cpu_to_le32(ctrl->dwFrameInterval);
*(__le16 *)&data[8] = cpu_to_le16(ctrl->wKeyFrameRate);
*(__le16 *)&data[10] = cpu_to_le16(ctrl->wPFrameRate);
*(__le16 *)&data[12] = cpu_to_le16(ctrl->wCompQuality);
*(__le16 *)&data[14] = cpu_to_le16(ctrl->wCompWindowSize);
*(__le16 *)&data[16] = cpu_to_le16(ctrl->wDelay);
put_unaligned_le32(ctrl->dwMaxVideoFrameSize, &data[18]);
put_unaligned_le32(ctrl->dwMaxPayloadTransferSize, &data[22]);
if (size == 34) {
put_unaligned_le32(ctrl->dwClockFrequency, &data[26]);
data[30] = ctrl->bmFramingInfo;
data[31] = ctrl->bPreferedVersion;
data[32] = ctrl->bMinVersion;
data[33] = ctrl->bMaxVersion;
}
ret = __uvc_query_ctrl(stream->dev, UVC_SET_CUR, 0, stream->intfnum,
probe ? UVC_VS_PROBE_CONTROL : UVC_VS_COMMIT_CONTROL, data,
size, uvc_timeout_param);
if (ret != size) {
uvc_printk(KERN_ERR, "Failed to set UVC %s control : "
"%d (exp. %u).\n", probe ? "probe" : "commit",
ret, size);
ret = -EIO;
}
kfree(data);
return ret;
}
int uvc_probe_video(struct uvc_streaming *stream,
struct uvc_streaming_control *probe)
{
struct uvc_streaming_control probe_min, probe_max;
__u16 bandwidth;
unsigned int i;
int ret;
/* Perform probing. The device should adjust the requested values
* according to its capabilities. However, some devices, namely the
* first generation UVC Logitech webcams, don't implement the Video
* Probe control properly, and just return the needed bandwidth. For
* that reason, if the needed bandwidth exceeds the maximum available
* bandwidth, try to lower the quality.
*/
ret = uvc_set_video_ctrl(stream, probe, 1);
if (ret < 0)
goto done;
/* Get the minimum and maximum values for compression settings. */
if (!(stream->dev->quirks & UVC_QUIRK_PROBE_MINMAX)) {
ret = uvc_get_video_ctrl(stream, &probe_min, 1, UVC_GET_MIN);
if (ret < 0)
goto done;
ret = uvc_get_video_ctrl(stream, &probe_max, 1, UVC_GET_MAX);
if (ret < 0)
goto done;
probe->wCompQuality = probe_max.wCompQuality;
}
for (i = 0; i < 2; ++i) {
ret = uvc_set_video_ctrl(stream, probe, 1);
if (ret < 0)
goto done;
ret = uvc_get_video_ctrl(stream, probe, 1, UVC_GET_CUR);
if (ret < 0)
goto done;
if (stream->intf->num_altsetting == 1)
break;
bandwidth = probe->dwMaxPayloadTransferSize;
if (bandwidth <= stream->maxpsize)
break;
if (stream->dev->quirks & UVC_QUIRK_PROBE_MINMAX) {
ret = -ENOSPC;
goto done;
}
/* TODO: negotiate compression parameters */
probe->wKeyFrameRate = probe_min.wKeyFrameRate;
probe->wPFrameRate = probe_min.wPFrameRate;
probe->wCompQuality = probe_max.wCompQuality;
probe->wCompWindowSize = probe_min.wCompWindowSize;
}
done:
return ret;
}
int uvc_commit_video(struct uvc_streaming *stream,
struct uvc_streaming_control *probe)
{
return uvc_set_video_ctrl(stream, probe, 0);
}
/* ------------------------------------------------------------------------
* Video codecs
*/
/* Values for bmHeaderInfo (Video and Still Image Payload Headers, 2.4.3.3) */
#define UVC_STREAM_EOH (1 << 7)
#define UVC_STREAM_ERR (1 << 6)
#define UVC_STREAM_STI (1 << 5)
#define UVC_STREAM_RES (1 << 4)
#define UVC_STREAM_SCR (1 << 3)
#define UVC_STREAM_PTS (1 << 2)
#define UVC_STREAM_EOF (1 << 1)
#define UVC_STREAM_FID (1 << 0)
/* Video payload decoding is handled by uvc_video_decode_start(),
* uvc_video_decode_data() and uvc_video_decode_end().
*
* uvc_video_decode_start is called with URB data at the start of a bulk or
* isochronous payload. It processes header data and returns the header size
* in bytes if successful. If an error occurs, it returns a negative error
* code. The following error codes have special meanings.
*
* - EAGAIN informs the caller that the current video buffer should be marked
* as done, and that the function should be called again with the same data
* and a new video buffer. This is used when end of frame conditions can be
* reliably detected at the beginning of the next frame only.
*
* If an error other than -EAGAIN is returned, the caller will drop the current
* payload. No call to uvc_video_decode_data and uvc_video_decode_end will be
* made until the next payload. -ENODATA can be used to drop the current
* payload if no other error code is appropriate.
*
* uvc_video_decode_data is called for every URB with URB data. It copies the
* data to the video buffer.
*
* uvc_video_decode_end is called with header data at the end of a bulk or
* isochronous payload. It performs any additional header data processing and
* returns 0 or a negative error code if an error occurred. As header data have
* already been processed by uvc_video_decode_start, this functions isn't
* required to perform sanity checks a second time.
*
* For isochronous transfers where a payload is always transferred in a single
* URB, the three functions will be called in a row.
*
* To let the decoder process header data and update its internal state even
* when no video buffer is available, uvc_video_decode_start must be prepared
* to be called with a NULL buf parameter. uvc_video_decode_data and
* uvc_video_decode_end will never be called with a NULL buffer.
*/
static int uvc_video_decode_start(struct uvc_streaming *stream,
struct uvc_buffer *buf, const __u8 *data, int len)
{
__u8 fid;
/* Sanity checks:
* - packet must be at least 2 bytes long
* - bHeaderLength value must be at least 2 bytes (see above)
* - bHeaderLength value can't be larger than the packet size.
*/
if (len < 2 || data[0] < 2 || data[0] > len)
return -EINVAL;
/* Skip payloads marked with the error bit ("error frames"). */
if (data[1] & UVC_STREAM_ERR) {
uvc_trace(UVC_TRACE_FRAME, "Dropping payload (error bit "
"set).\n");
return -ENODATA;
}
fid = data[1] & UVC_STREAM_FID;
/* Increase the sequence number regardless of any buffer states, so
* that discontinuous sequence numbers always indicate lost frames.
*/
if (stream->last_fid != fid)
stream->sequence++;
/* Store the payload FID bit and return immediately when the buffer is
* NULL.
*/
if (buf == NULL) {
stream->last_fid = fid;
return -ENODATA;
}
/* Synchronize to the input stream by waiting for the FID bit to be
* toggled when the the buffer state is not UVC_BUF_STATE_ACTIVE.
* stream->last_fid is initialized to -1, so the first isochronous
* frame will always be in sync.
*
* If the device doesn't toggle the FID bit, invert stream->last_fid
* when the EOF bit is set to force synchronisation on the next packet.
*/
if (buf->state != UVC_BUF_STATE_ACTIVE) {
struct timespec ts;
if (fid == stream->last_fid) {
uvc_trace(UVC_TRACE_FRAME, "Dropping payload (out of "
"sync).\n");
if ((stream->dev->quirks & UVC_QUIRK_STREAM_NO_FID) &&
(data[1] & UVC_STREAM_EOF))
stream->last_fid ^= UVC_STREAM_FID;
return -ENODATA;
}
if (uvc_clock_param == CLOCK_MONOTONIC)
ktime_get_ts(&ts);
else
ktime_get_real_ts(&ts);
buf->buf.sequence = stream->sequence;
buf->buf.timestamp.tv_sec = ts.tv_sec;
buf->buf.timestamp.tv_usec = ts.tv_nsec / NSEC_PER_USEC;
/* TODO: Handle PTS and SCR. */
buf->state = UVC_BUF_STATE_ACTIVE;
}
/* Mark the buffer as done if we're at the beginning of a new frame.
* End of frame detection is better implemented by checking the EOF
* bit (FID bit toggling is delayed by one frame compared to the EOF
* bit), but some devices don't set the bit at end of frame (and the
* last payload can be lost anyway). We thus must check if the FID has
* been toggled.
*
* stream->last_fid is initialized to -1, so the first isochronous
* frame will never trigger an end of frame detection.
*
* Empty buffers (bytesused == 0) don't trigger end of frame detection
* as it doesn't make sense to return an empty buffer. This also
* avoids detecting end of frame conditions at FID toggling if the
* previous payload had the EOF bit set.
*/
if (fid != stream->last_fid && buf->buf.bytesused != 0) {
uvc_trace(UVC_TRACE_FRAME, "Frame complete (FID bit "
"toggled).\n");
buf->state = UVC_BUF_STATE_READY;
return -EAGAIN;
}
stream->last_fid = fid;
return data[0];
}
static void uvc_video_decode_data(struct uvc_streaming *stream,
struct uvc_buffer *buf, const __u8 *data, int len)
{
struct uvc_video_queue *queue = &stream->queue;
unsigned int maxlen, nbytes;
void *mem;
if (len <= 0)
return;
/* Copy the video data to the buffer. */
maxlen = buf->buf.length - buf->buf.bytesused;
mem = queue->mem + buf->buf.m.offset + buf->buf.bytesused;
nbytes = min((unsigned int)len, maxlen);
memcpy(mem, data, nbytes);
buf->buf.bytesused += nbytes;
/* Complete the current frame if the buffer size was exceeded. */
if (len > maxlen) {
uvc_trace(UVC_TRACE_FRAME, "Frame complete (overflow).\n");
buf->state = UVC_BUF_STATE_READY;
}
}
static void uvc_video_decode_end(struct uvc_streaming *stream,
struct uvc_buffer *buf, const __u8 *data, int len)
{
/* Mark the buffer as done if the EOF marker is set. */
if (data[1] & UVC_STREAM_EOF && buf->buf.bytesused != 0) {
uvc_trace(UVC_TRACE_FRAME, "Frame complete (EOF found).\n");
if (data[0] == len)
uvc_trace(UVC_TRACE_FRAME, "EOF in empty payload.\n");
buf->state = UVC_BUF_STATE_READY;
if (stream->dev->quirks & UVC_QUIRK_STREAM_NO_FID)
stream->last_fid ^= UVC_STREAM_FID;
}
}
/* Video payload encoding is handled by uvc_video_encode_header() and
* uvc_video_encode_data(). Only bulk transfers are currently supported.
*
* uvc_video_encode_header is called at the start of a payload. It adds header
* data to the transfer buffer and returns the header size. As the only known
* UVC output device transfers a whole frame in a single payload, the EOF bit
* is always set in the header.
*
* uvc_video_encode_data is called for every URB and copies the data from the
* video buffer to the transfer buffer.
*/
static int uvc_video_encode_header(struct uvc_streaming *stream,
struct uvc_buffer *buf, __u8 *data, int len)
{
data[0] = 2; /* Header length */
data[1] = UVC_STREAM_EOH | UVC_STREAM_EOF
| (stream->last_fid & UVC_STREAM_FID);
return 2;
}
static int uvc_video_encode_data(struct uvc_streaming *stream,
struct uvc_buffer *buf, __u8 *data, int len)
{
struct uvc_video_queue *queue = &stream->queue;
unsigned int nbytes;
void *mem;
/* Copy video data to the URB buffer. */
mem = queue->mem + buf->buf.m.offset + queue->buf_used;
nbytes = min((unsigned int)len, buf->buf.bytesused - queue->buf_used);
nbytes = min(stream->bulk.max_payload_size - stream->bulk.payload_size,
nbytes);
memcpy(data, mem, nbytes);
queue->buf_used += nbytes;
return nbytes;
}
/* ------------------------------------------------------------------------
* URB handling
*/
/*
* Completion handler for video URBs.
*/
static void uvc_video_decode_isoc(struct urb *urb, struct uvc_streaming *stream,
struct uvc_buffer *buf)
{
u8 *mem;
int ret, i;
for (i = 0; i < urb->number_of_packets; ++i) {
if (urb->iso_frame_desc[i].status < 0) {
uvc_trace(UVC_TRACE_FRAME, "USB isochronous frame "
"lost (%d).\n", urb->iso_frame_desc[i].status);
/* Mark the buffer as faulty. */
if (buf != NULL)
buf->error = 1;
continue;
}
/* Decode the payload header. */
mem = urb->transfer_buffer + urb->iso_frame_desc[i].offset;
do {
ret = uvc_video_decode_start(stream, buf, mem,
urb->iso_frame_desc[i].actual_length);
if (ret == -EAGAIN)
buf = uvc_queue_next_buffer(&stream->queue,
buf);
} while (ret == -EAGAIN);
if (ret < 0)
continue;
/* Decode the payload data. */
uvc_video_decode_data(stream, buf, mem + ret,
urb->iso_frame_desc[i].actual_length - ret);
/* Process the header again. */
uvc_video_decode_end(stream, buf, mem,
urb->iso_frame_desc[i].actual_length);
if (buf->state == UVC_BUF_STATE_READY) {
if (buf->buf.length != buf->buf.bytesused &&
!(stream->cur_format->flags &
UVC_FMT_FLAG_COMPRESSED))
buf->error = 1;
buf = uvc_queue_next_buffer(&stream->queue, buf);
}
}
}
static void uvc_video_decode_bulk(struct urb *urb, struct uvc_streaming *stream,
struct uvc_buffer *buf)
{
u8 *mem;
int len, ret;
if (urb->actual_length == 0)
return;
mem = urb->transfer_buffer;
len = urb->actual_length;
stream->bulk.payload_size += len;
/* If the URB is the first of its payload, decode and save the
* header.
*/
if (stream->bulk.header_size == 0 && !stream->bulk.skip_payload) {
do {
ret = uvc_video_decode_start(stream, buf, mem, len);
if (ret == -EAGAIN)
buf = uvc_queue_next_buffer(&stream->queue,
buf);
} while (ret == -EAGAIN);
/* If an error occurred skip the rest of the payload. */
if (ret < 0 || buf == NULL) {
stream->bulk.skip_payload = 1;
} else {
memcpy(stream->bulk.header, mem, ret);
stream->bulk.header_size = ret;
mem += ret;
len -= ret;
}
}
/* The buffer queue might have been cancelled while a bulk transfer
* was in progress, so we can reach here with buf equal to NULL. Make
* sure buf is never dereferenced if NULL.
*/
/* Process video data. */
if (!stream->bulk.skip_payload && buf != NULL)
uvc_video_decode_data(stream, buf, mem, len);
/* Detect the payload end by a URB smaller than the maximum size (or
* a payload size equal to the maximum) and process the header again.
*/
if (urb->actual_length < urb->transfer_buffer_length ||
stream->bulk.payload_size >= stream->bulk.max_payload_size) {
if (!stream->bulk.skip_payload && buf != NULL) {
uvc_video_decode_end(stream, buf, stream->bulk.header,
stream->bulk.payload_size);
if (buf->state == UVC_BUF_STATE_READY)
buf = uvc_queue_next_buffer(&stream->queue,
buf);
}
stream->bulk.header_size = 0;
stream->bulk.skip_payload = 0;
stream->bulk.payload_size = 0;
}
}
static void uvc_video_encode_bulk(struct urb *urb, struct uvc_streaming *stream,
struct uvc_buffer *buf)
{
u8 *mem = urb->transfer_buffer;
int len = stream->urb_size, ret;
if (buf == NULL) {
urb->transfer_buffer_length = 0;
return;
}
/* If the URB is the first of its payload, add the header. */
if (stream->bulk.header_size == 0) {
ret = uvc_video_encode_header(stream, buf, mem, len);
stream->bulk.header_size = ret;
stream->bulk.payload_size += ret;
mem += ret;
len -= ret;
}
/* Process video data. */
ret = uvc_video_encode_data(stream, buf, mem, len);
stream->bulk.payload_size += ret;
len -= ret;
if (buf->buf.bytesused == stream->queue.buf_used ||
stream->bulk.payload_size == stream->bulk.max_payload_size) {
if (buf->buf.bytesused == stream->queue.buf_used) {
stream->queue.buf_used = 0;
buf->state = UVC_BUF_STATE_READY;
buf->buf.sequence = ++stream->sequence;
uvc_queue_next_buffer(&stream->queue, buf);
stream->last_fid ^= UVC_STREAM_FID;
}
stream->bulk.header_size = 0;
stream->bulk.payload_size = 0;
}
urb->transfer_buffer_length = stream->urb_size - len;
}
static void uvc_video_complete(struct urb *urb)
{
struct uvc_streaming *stream = urb->context;
struct uvc_video_queue *queue = &stream->queue;
struct uvc_buffer *buf = NULL;
unsigned long flags;
int ret;
switch (urb->status) {
case 0:
break;
default:
uvc_printk(KERN_WARNING, "Non-zero status (%d) in video "
"completion handler.\n", urb->status);
case -ENOENT: /* usb_kill_urb() called. */
if (stream->frozen)
return;
case -ECONNRESET: /* usb_unlink_urb() called. */
case -ESHUTDOWN: /* The endpoint is being disabled. */
uvc_queue_cancel(queue, urb->status == -ESHUTDOWN);
return;
}
spin_lock_irqsave(&queue->irqlock, flags);
if (!list_empty(&queue->irqqueue))
buf = list_first_entry(&queue->irqqueue, struct uvc_buffer,
queue);
spin_unlock_irqrestore(&queue->irqlock, flags);
stream->decode(urb, stream, buf);
if ((ret = usb_submit_urb(urb, GFP_ATOMIC)) < 0) {
uvc_printk(KERN_ERR, "Failed to resubmit video URB (%d).\n",
ret);
}
}
/*
* Free transfer buffers.
*/
static void uvc_free_urb_buffers(struct uvc_streaming *stream)
{
unsigned int i;
for (i = 0; i < UVC_URBS; ++i) {
if (stream->urb_buffer[i]) {
usb_free_coherent(stream->dev->udev, stream->urb_size,
stream->urb_buffer[i], stream->urb_dma[i]);
stream->urb_buffer[i] = NULL;
}
}
stream->urb_size = 0;
}
/*
* Allocate transfer buffers. This function can be called with buffers
* already allocated when resuming from suspend, in which case it will
* return without touching the buffers.
*
* Limit the buffer size to UVC_MAX_PACKETS bulk/isochronous packets. If the
* system is too low on memory try successively smaller numbers of packets
* until allocation succeeds.
*
* Return the number of allocated packets on success or 0 when out of memory.
*/
static int uvc_alloc_urb_buffers(struct uvc_streaming *stream,
unsigned int size, unsigned int psize, gfp_t gfp_flags)
{
unsigned int npackets;
unsigned int i;
/* Buffers are already allocated, bail out. */
if (stream->urb_size)
return stream->urb_size / psize;
/* Compute the number of packets. Bulk endpoints might transfer UVC
* payloads across multiple URBs.
*/
npackets = DIV_ROUND_UP(size, psize);
if (npackets > UVC_MAX_PACKETS)
npackets = UVC_MAX_PACKETS;
/* Retry allocations until one succeed. */
for (; npackets > 1; npackets /= 2) {
for (i = 0; i < UVC_URBS; ++i) {
stream->urb_size = psize * npackets;
stream->urb_buffer[i] = usb_alloc_coherent(
stream->dev->udev, stream->urb_size,
gfp_flags | __GFP_NOWARN, &stream->urb_dma[i]);
if (!stream->urb_buffer[i]) {
uvc_free_urb_buffers(stream);
break;
}
}
if (i == UVC_URBS) {
uvc_trace(UVC_TRACE_VIDEO, "Allocated %u URB buffers "
"of %ux%u bytes each.\n", UVC_URBS, npackets,
psize);
return npackets;
}
}
uvc_trace(UVC_TRACE_VIDEO, "Failed to allocate URB buffers (%u bytes "
"per packet).\n", psize);
return 0;
}
/*
* Uninitialize isochronous/bulk URBs and free transfer buffers.
*/
static void uvc_uninit_video(struct uvc_streaming *stream, int free_buffers)
{
struct urb *urb;
unsigned int i;
for (i = 0; i < UVC_URBS; ++i) {
urb = stream->urb[i];
if (urb == NULL)
continue;
usb_kill_urb(urb);
usb_free_urb(urb);
stream->urb[i] = NULL;
}
if (free_buffers)
uvc_free_urb_buffers(stream);
}
/*
* Initialize isochronous URBs and allocate transfer buffers. The packet size
* is given by the endpoint.
*/
static int uvc_init_video_isoc(struct uvc_streaming *stream,
struct usb_host_endpoint *ep, gfp_t gfp_flags)
{
struct urb *urb;
unsigned int npackets, i, j;
u16 psize;
u32 size;
psize = le16_to_cpu(ep->desc.wMaxPacketSize);
psize = (psize & 0x07ff) * (1 + ((psize >> 11) & 3));
size = stream->ctrl.dwMaxVideoFrameSize;
npackets = uvc_alloc_urb_buffers(stream, size, psize, gfp_flags);
if (npackets == 0)
return -ENOMEM;
size = npackets * psize;
for (i = 0; i < UVC_URBS; ++i) {
urb = usb_alloc_urb(npackets, gfp_flags);
if (urb == NULL) {
uvc_uninit_video(stream, 1);
return -ENOMEM;
}
urb->dev = stream->dev->udev;
urb->context = stream;
urb->pipe = usb_rcvisocpipe(stream->dev->udev,
ep->desc.bEndpointAddress);
urb->transfer_flags = URB_ISO_ASAP | URB_NO_TRANSFER_DMA_MAP;
urb->interval = ep->desc.bInterval;
urb->transfer_buffer = stream->urb_buffer[i];
urb->transfer_dma = stream->urb_dma[i];
urb->complete = uvc_video_complete;
urb->number_of_packets = npackets;
urb->transfer_buffer_length = size;
for (j = 0; j < npackets; ++j) {
urb->iso_frame_desc[j].offset = j * psize;
urb->iso_frame_desc[j].length = psize;
}
stream->urb[i] = urb;
}
return 0;
}
/*
* Initialize bulk URBs and allocate transfer buffers. The packet size is
* given by the endpoint.
*/
static int uvc_init_video_bulk(struct uvc_streaming *stream,
struct usb_host_endpoint *ep, gfp_t gfp_flags)
{
struct urb *urb;
unsigned int npackets, pipe, i;
u16 psize;
u32 size;
psize = le16_to_cpu(ep->desc.wMaxPacketSize) & 0x07ff;
size = stream->ctrl.dwMaxPayloadTransferSize;
stream->bulk.max_payload_size = size;
npackets = uvc_alloc_urb_buffers(stream, size, psize, gfp_flags);
if (npackets == 0)
return -ENOMEM;
size = npackets * psize;
if (usb_endpoint_dir_in(&ep->desc))
pipe = usb_rcvbulkpipe(stream->dev->udev,
ep->desc.bEndpointAddress);
else
pipe = usb_sndbulkpipe(stream->dev->udev,
ep->desc.bEndpointAddress);
if (stream->type == V4L2_BUF_TYPE_VIDEO_OUTPUT)
size = 0;
for (i = 0; i < UVC_URBS; ++i) {
urb = usb_alloc_urb(0, gfp_flags);
if (urb == NULL) {
uvc_uninit_video(stream, 1);
return -ENOMEM;
}
usb_fill_bulk_urb(urb, stream->dev->udev, pipe,
stream->urb_buffer[i], size, uvc_video_complete,
stream);
urb->transfer_flags = URB_NO_TRANSFER_DMA_MAP;
urb->transfer_dma = stream->urb_dma[i];
stream->urb[i] = urb;
}
return 0;
}
/*
* Initialize isochronous/bulk URBs and allocate transfer buffers.
*/
static int uvc_init_video(struct uvc_streaming *stream, gfp_t gfp_flags)
{
struct usb_interface *intf = stream->intf;
struct usb_host_endpoint *ep;
unsigned int i;
int ret;
stream->sequence = -1;
stream->last_fid = -1;
stream->bulk.header_size = 0;
stream->bulk.skip_payload = 0;
stream->bulk.payload_size = 0;
if (intf->num_altsetting > 1) {
struct usb_host_endpoint *best_ep = NULL;
unsigned int best_psize = 3 * 1024;
unsigned int bandwidth;
unsigned int uninitialized_var(altsetting);
int intfnum = stream->intfnum;
/* Isochronous endpoint, select the alternate setting. */
bandwidth = stream->ctrl.dwMaxPayloadTransferSize;
if (bandwidth == 0) {
uvc_trace(UVC_TRACE_VIDEO, "Device requested null "
"bandwidth, defaulting to lowest.\n");
bandwidth = 1;
} else {
uvc_trace(UVC_TRACE_VIDEO, "Device requested %u "
"B/frame bandwidth.\n", bandwidth);
}
for (i = 0; i < intf->num_altsetting; ++i) {
struct usb_host_interface *alts;
unsigned int psize;
alts = &intf->altsetting[i];
ep = uvc_find_endpoint(alts,
stream->header.bEndpointAddress);
if (ep == NULL)
continue;
/* Check if the bandwidth is high enough. */
psize = le16_to_cpu(ep->desc.wMaxPacketSize);
psize = (psize & 0x07ff) * (1 + ((psize >> 11) & 3));
if (psize >= bandwidth && psize <= best_psize) {
altsetting = i;
best_psize = psize;
best_ep = ep;
}
}
if (best_ep == NULL) {
uvc_trace(UVC_TRACE_VIDEO, "No fast enough alt setting "
"for requested bandwidth.\n");
return -EIO;
}
uvc_trace(UVC_TRACE_VIDEO, "Selecting alternate setting %u "
"(%u B/frame bandwidth).\n", altsetting, best_psize);
ret = usb_set_interface(stream->dev->udev, intfnum, altsetting);
if (ret < 0)
return ret;
ret = uvc_init_video_isoc(stream, best_ep, gfp_flags);
} else {
/* Bulk endpoint, proceed to URB initialization. */
ep = uvc_find_endpoint(&intf->altsetting[0],
stream->header.bEndpointAddress);
if (ep == NULL)
return -EIO;
ret = uvc_init_video_bulk(stream, ep, gfp_flags);
}
if (ret < 0)
return ret;
/* Submit the URBs. */
for (i = 0; i < UVC_URBS; ++i) {
ret = usb_submit_urb(stream->urb[i], gfp_flags);
if (ret < 0) {
uvc_printk(KERN_ERR, "Failed to submit URB %u "
"(%d).\n", i, ret);
uvc_uninit_video(stream, 1);
return ret;
}
}
return 0;
}
/* --------------------------------------------------------------------------
* Suspend/resume
*/
/*
* Stop streaming without disabling the video queue.
*
* To let userspace applications resume without trouble, we must not touch the
* video buffers in any way. We mark the device as frozen to make sure the URB
* completion handler won't try to cancel the queue when we kill the URBs.
*/
int uvc_video_suspend(struct uvc_streaming *stream)
{
if (!uvc_queue_streaming(&stream->queue))
return 0;
stream->frozen = 1;
uvc_uninit_video(stream, 0);
usb_set_interface(stream->dev->udev, stream->intfnum, 0);
return 0;
}
/*
* Reconfigure the video interface and restart streaming if it was enabled
* before suspend.
*
* If an error occurs, disable the video queue. This will wake all pending
* buffers, making sure userspace applications are notified of the problem
* instead of waiting forever.
*/
int uvc_video_resume(struct uvc_streaming *stream)
{
int ret;
stream->frozen = 0;
ret = uvc_commit_video(stream, &stream->ctrl);
if (ret < 0) {
uvc_queue_enable(&stream->queue, 0);
return ret;
}
if (!uvc_queue_streaming(&stream->queue))
return 0;
ret = uvc_init_video(stream, GFP_NOIO);
if (ret < 0)
uvc_queue_enable(&stream->queue, 0);
return ret;
}
/* ------------------------------------------------------------------------
* Video device
*/
/*
* Initialize the UVC video device by switching to alternate setting 0 and
* retrieve the default format.
*
* Some cameras (namely the Fuji Finepix) set the format and frame
* indexes to zero. The UVC standard doesn't clearly make this a spec
* violation, so try to silently fix the values if possible.
*
* This function is called before registering the device with V4L.
*/
int uvc_video_init(struct uvc_streaming *stream)
{
struct uvc_streaming_control *probe = &stream->ctrl;
struct uvc_format *format = NULL;
struct uvc_frame *frame = NULL;
unsigned int i;
int ret;
if (stream->nformats == 0) {
uvc_printk(KERN_INFO, "No supported video formats found.\n");
return -EINVAL;
}
atomic_set(&stream->active, 0);
/* Initialize the video buffers queue. */
uvc_queue_init(&stream->queue, stream->type, !uvc_no_drop_param);
/* Alternate setting 0 should be the default, yet the XBox Live Vision
* Cam (and possibly other devices) crash or otherwise misbehave if
* they don't receive a SET_INTERFACE request before any other video
* control request.
*/
usb_set_interface(stream->dev->udev, stream->intfnum, 0);
/* Set the streaming probe control with default streaming parameters
* retrieved from the device. Webcams that don't suport GET_DEF
* requests on the probe control will just keep their current streaming
* parameters.
*/
if (uvc_get_video_ctrl(stream, probe, 1, UVC_GET_DEF) == 0)
uvc_set_video_ctrl(stream, probe, 1);
/* Initialize the streaming parameters with the probe control current
* value. This makes sure SET_CUR requests on the streaming commit
* control will always use values retrieved from a successful GET_CUR
* request on the probe control, as required by the UVC specification.
*/
ret = uvc_get_video_ctrl(stream, probe, 1, UVC_GET_CUR);
if (ret < 0)
return ret;
/* Check if the default format descriptor exists. Use the first
* available format otherwise.
*/
for (i = stream->nformats; i > 0; --i) {
format = &stream->format[i-1];
if (format->index == probe->bFormatIndex)
break;
}
if (format->nframes == 0) {
uvc_printk(KERN_INFO, "No frame descriptor found for the "
"default format.\n");
return -EINVAL;
}
/* Zero bFrameIndex might be correct. Stream-based formats (including
* MPEG-2 TS and DV) do not support frames but have a dummy frame
* descriptor with bFrameIndex set to zero. If the default frame
* descriptor is not found, use the first available frame.
*/
for (i = format->nframes; i > 0; --i) {
frame = &format->frame[i-1];
if (frame->bFrameIndex == probe->bFrameIndex)
break;
}
probe->bFormatIndex = format->index;
probe->bFrameIndex = frame->bFrameIndex;
stream->cur_format = format;
stream->cur_frame = frame;
/* Select the video decoding function */
if (stream->type == V4L2_BUF_TYPE_VIDEO_CAPTURE) {
if (stream->dev->quirks & UVC_QUIRK_BUILTIN_ISIGHT)
stream->decode = uvc_video_decode_isight;
else if (stream->intf->num_altsetting > 1)
stream->decode = uvc_video_decode_isoc;
else
stream->decode = uvc_video_decode_bulk;
} else {
if (stream->intf->num_altsetting == 1)
stream->decode = uvc_video_encode_bulk;
else {
uvc_printk(KERN_INFO, "Isochronous endpoints are not "
"supported for video output devices.\n");
return -EINVAL;
}
}
return 0;
}
/*
* Enable or disable the video stream.
*/
int uvc_video_enable(struct uvc_streaming *stream, int enable)
{
int ret;
if (!enable) {
uvc_uninit_video(stream, 1);
usb_set_interface(stream->dev->udev, stream->intfnum, 0);
uvc_queue_enable(&stream->queue, 0);
return 0;
}
ret = uvc_queue_enable(&stream->queue, 1);
if (ret < 0)
return ret;
/* Commit the streaming parameters. */
ret = uvc_commit_video(stream, &stream->ctrl);
if (ret < 0) {
uvc_queue_enable(&stream->queue, 0);
return ret;
}
return uvc_init_video(stream, GFP_KERNEL);
}
|