2 * uvc_video.c -- USB Video Class driver - Video handling
4 * Copyright (C) 2005-2010
5 * Laurent Pinchart (laurent.pinchart@ideasonboard.com)
7 * This program is free software; you can redistribute it and/or modify
8 * it under the terms of the GNU General Public License as published by
9 * the Free Software Foundation; either version 2 of the License, or
10 * (at your option) any later version.
14 #include <linux/kernel.h>
15 #include <linux/list.h>
16 #include <linux/module.h>
17 #include <linux/slab.h>
18 #include <linux/usb.h>
19 #include <linux/videodev2.h>
20 #include <linux/vmalloc.h>
21 #include <linux/wait.h>
22 #include <linux/atomic.h>
23 #include <asm/unaligned.h>
25 #include <media/v4l2-common.h>
29 /* ------------------------------------------------------------------------
33 static int __uvc_query_ctrl(struct uvc_device
*dev
, __u8 query
, __u8 unit
,
34 __u8 intfnum
, __u8 cs
, void *data
, __u16 size
,
37 __u8 type
= USB_TYPE_CLASS
| USB_RECIP_INTERFACE
;
40 pipe
= (query
& 0x80) ? usb_rcvctrlpipe(dev
->udev
, 0)
41 : usb_sndctrlpipe(dev
->udev
, 0);
42 type
|= (query
& 0x80) ? USB_DIR_IN
: USB_DIR_OUT
;
44 return usb_control_msg(dev
->udev
, pipe
, query
, type
, cs
<< 8,
45 unit
<< 8 | intfnum
, data
, size
, timeout
);
48 static const char *uvc_query_name(__u8 query
)
72 int uvc_query_ctrl(struct uvc_device
*dev
, __u8 query
, __u8 unit
,
73 __u8 intfnum
, __u8 cs
, void *data
, __u16 size
)
77 ret
= __uvc_query_ctrl(dev
, query
, unit
, intfnum
, cs
, data
, size
,
78 UVC_CTRL_CONTROL_TIMEOUT
);
80 uvc_printk(KERN_ERR
, "Failed to query (%s) UVC control %u on "
81 "unit %u: %d (exp. %u).\n", uvc_query_name(query
), cs
,
89 static void uvc_fixup_video_ctrl(struct uvc_streaming
*stream
,
90 struct uvc_streaming_control
*ctrl
)
92 struct uvc_format
*format
= NULL
;
93 struct uvc_frame
*frame
= NULL
;
96 for (i
= 0; i
< stream
->nformats
; ++i
) {
97 if (stream
->format
[i
].index
== ctrl
->bFormatIndex
) {
98 format
= &stream
->format
[i
];
106 for (i
= 0; i
< format
->nframes
; ++i
) {
107 if (format
->frame
[i
].bFrameIndex
== ctrl
->bFrameIndex
) {
108 frame
= &format
->frame
[i
];
116 if (!(format
->flags
& UVC_FMT_FLAG_COMPRESSED
) ||
117 (ctrl
->dwMaxVideoFrameSize
== 0 &&
118 stream
->dev
->uvc_version
< 0x0110))
119 ctrl
->dwMaxVideoFrameSize
=
120 frame
->dwMaxVideoFrameBufferSize
;
122 if (!(format
->flags
& UVC_FMT_FLAG_COMPRESSED
) &&
123 stream
->dev
->quirks
& UVC_QUIRK_FIX_BANDWIDTH
&&
124 stream
->intf
->num_altsetting
> 1) {
128 interval
= (ctrl
->dwFrameInterval
> 100000)
129 ? ctrl
->dwFrameInterval
130 : frame
->dwFrameInterval
[0];
132 /* Compute a bandwidth estimation by multiplying the frame
133 * size by the number of video frames per second, divide the
134 * result by the number of USB frames (or micro-frames for
135 * high-speed devices) per second and add the UVC header size
136 * (assumed to be 12 bytes long).
138 bandwidth
= frame
->wWidth
* frame
->wHeight
/ 8 * format
->bpp
;
139 bandwidth
*= 10000000 / interval
+ 1;
141 if (stream
->dev
->udev
->speed
== USB_SPEED_HIGH
)
145 /* The bandwidth estimate is too low for many cameras. Don't use
146 * maximum packet sizes lower than 1024 bytes to try and work
147 * around the problem. According to measurements done on two
148 * different camera models, the value is high enough to get most
149 * resolutions working while not preventing two simultaneous
150 * VGA streams at 15 fps.
152 bandwidth
= max_t(u32
, bandwidth
, 1024);
154 ctrl
->dwMaxPayloadTransferSize
= bandwidth
;
158 static int uvc_get_video_ctrl(struct uvc_streaming
*stream
,
159 struct uvc_streaming_control
*ctrl
, int probe
, __u8 query
)
165 size
= stream
->dev
->uvc_version
>= 0x0110 ? 34 : 26;
166 if ((stream
->dev
->quirks
& UVC_QUIRK_PROBE_DEF
) &&
167 query
== UVC_GET_DEF
)
170 data
= kmalloc(size
, GFP_KERNEL
);
174 ret
= __uvc_query_ctrl(stream
->dev
, query
, 0, stream
->intfnum
,
175 probe
? UVC_VS_PROBE_CONTROL
: UVC_VS_COMMIT_CONTROL
, data
,
176 size
, uvc_timeout_param
);
178 if ((query
== UVC_GET_MIN
|| query
== UVC_GET_MAX
) && ret
== 2) {
179 /* Some cameras, mostly based on Bison Electronics chipsets,
180 * answer a GET_MIN or GET_MAX request with the wCompQuality
183 uvc_warn_once(stream
->dev
, UVC_WARN_MINMAX
, "UVC non "
184 "compliance - GET_MIN/MAX(PROBE) incorrectly "
185 "supported. Enabling workaround.\n");
186 memset(ctrl
, 0, sizeof *ctrl
);
187 ctrl
->wCompQuality
= le16_to_cpup((__le16
*)data
);
190 } else if (query
== UVC_GET_DEF
&& probe
== 1 && ret
!= size
) {
191 /* Many cameras don't support the GET_DEF request on their
192 * video probe control. Warn once and return, the caller will
193 * fall back to GET_CUR.
195 uvc_warn_once(stream
->dev
, UVC_WARN_PROBE_DEF
, "UVC non "
196 "compliance - GET_DEF(PROBE) not supported. "
197 "Enabling workaround.\n");
200 } else if (ret
!= size
) {
201 uvc_printk(KERN_ERR
, "Failed to query (%u) UVC %s control : "
202 "%d (exp. %u).\n", query
, probe
? "probe" : "commit",
208 ctrl
->bmHint
= le16_to_cpup((__le16
*)&data
[0]);
209 ctrl
->bFormatIndex
= data
[2];
210 ctrl
->bFrameIndex
= data
[3];
211 ctrl
->dwFrameInterval
= le32_to_cpup((__le32
*)&data
[4]);
212 ctrl
->wKeyFrameRate
= le16_to_cpup((__le16
*)&data
[8]);
213 ctrl
->wPFrameRate
= le16_to_cpup((__le16
*)&data
[10]);
214 ctrl
->wCompQuality
= le16_to_cpup((__le16
*)&data
[12]);
215 ctrl
->wCompWindowSize
= le16_to_cpup((__le16
*)&data
[14]);
216 ctrl
->wDelay
= le16_to_cpup((__le16
*)&data
[16]);
217 ctrl
->dwMaxVideoFrameSize
= get_unaligned_le32(&data
[18]);
218 ctrl
->dwMaxPayloadTransferSize
= get_unaligned_le32(&data
[22]);
221 ctrl
->dwClockFrequency
= get_unaligned_le32(&data
[26]);
222 ctrl
->bmFramingInfo
= data
[30];
223 ctrl
->bPreferedVersion
= data
[31];
224 ctrl
->bMinVersion
= data
[32];
225 ctrl
->bMaxVersion
= data
[33];
227 ctrl
->dwClockFrequency
= stream
->dev
->clock_frequency
;
228 ctrl
->bmFramingInfo
= 0;
229 ctrl
->bPreferedVersion
= 0;
230 ctrl
->bMinVersion
= 0;
231 ctrl
->bMaxVersion
= 0;
234 /* Some broken devices return null or wrong dwMaxVideoFrameSize and
235 * dwMaxPayloadTransferSize fields. Try to get the value from the
236 * format and frame descriptors.
238 uvc_fixup_video_ctrl(stream
, ctrl
);
246 static int uvc_set_video_ctrl(struct uvc_streaming
*stream
,
247 struct uvc_streaming_control
*ctrl
, int probe
)
253 size
= stream
->dev
->uvc_version
>= 0x0110 ? 34 : 26;
254 data
= kzalloc(size
, GFP_KERNEL
);
258 *(__le16
*)&data
[0] = cpu_to_le16(ctrl
->bmHint
);
259 data
[2] = ctrl
->bFormatIndex
;
260 data
[3] = ctrl
->bFrameIndex
;
261 *(__le32
*)&data
[4] = cpu_to_le32(ctrl
->dwFrameInterval
);
262 *(__le16
*)&data
[8] = cpu_to_le16(ctrl
->wKeyFrameRate
);
263 *(__le16
*)&data
[10] = cpu_to_le16(ctrl
->wPFrameRate
);
264 *(__le16
*)&data
[12] = cpu_to_le16(ctrl
->wCompQuality
);
265 *(__le16
*)&data
[14] = cpu_to_le16(ctrl
->wCompWindowSize
);
266 *(__le16
*)&data
[16] = cpu_to_le16(ctrl
->wDelay
);
267 put_unaligned_le32(ctrl
->dwMaxVideoFrameSize
, &data
[18]);
268 put_unaligned_le32(ctrl
->dwMaxPayloadTransferSize
, &data
[22]);
271 put_unaligned_le32(ctrl
->dwClockFrequency
, &data
[26]);
272 data
[30] = ctrl
->bmFramingInfo
;
273 data
[31] = ctrl
->bPreferedVersion
;
274 data
[32] = ctrl
->bMinVersion
;
275 data
[33] = ctrl
->bMaxVersion
;
278 ret
= __uvc_query_ctrl(stream
->dev
, UVC_SET_CUR
, 0, stream
->intfnum
,
279 probe
? UVC_VS_PROBE_CONTROL
: UVC_VS_COMMIT_CONTROL
, data
,
280 size
, uvc_timeout_param
);
282 uvc_printk(KERN_ERR
, "Failed to set UVC %s control : "
283 "%d (exp. %u).\n", probe
? "probe" : "commit",
292 int uvc_probe_video(struct uvc_streaming
*stream
,
293 struct uvc_streaming_control
*probe
)
295 struct uvc_streaming_control probe_min
, probe_max
;
300 /* Perform probing. The device should adjust the requested values
301 * according to its capabilities. However, some devices, namely the
302 * first generation UVC Logitech webcams, don't implement the Video
303 * Probe control properly, and just return the needed bandwidth. For
304 * that reason, if the needed bandwidth exceeds the maximum available
305 * bandwidth, try to lower the quality.
307 ret
= uvc_set_video_ctrl(stream
, probe
, 1);
311 /* Get the minimum and maximum values for compression settings. */
312 if (!(stream
->dev
->quirks
& UVC_QUIRK_PROBE_MINMAX
)) {
313 ret
= uvc_get_video_ctrl(stream
, &probe_min
, 1, UVC_GET_MIN
);
316 ret
= uvc_get_video_ctrl(stream
, &probe_max
, 1, UVC_GET_MAX
);
320 probe
->wCompQuality
= probe_max
.wCompQuality
;
323 for (i
= 0; i
< 2; ++i
) {
324 ret
= uvc_set_video_ctrl(stream
, probe
, 1);
327 ret
= uvc_get_video_ctrl(stream
, probe
, 1, UVC_GET_CUR
);
331 if (stream
->intf
->num_altsetting
== 1)
334 bandwidth
= probe
->dwMaxPayloadTransferSize
;
335 if (bandwidth
<= stream
->maxpsize
)
338 if (stream
->dev
->quirks
& UVC_QUIRK_PROBE_MINMAX
) {
343 /* TODO: negotiate compression parameters */
344 probe
->wKeyFrameRate
= probe_min
.wKeyFrameRate
;
345 probe
->wPFrameRate
= probe_min
.wPFrameRate
;
346 probe
->wCompQuality
= probe_max
.wCompQuality
;
347 probe
->wCompWindowSize
= probe_min
.wCompWindowSize
;
354 static int uvc_commit_video(struct uvc_streaming
*stream
,
355 struct uvc_streaming_control
*probe
)
357 return uvc_set_video_ctrl(stream
, probe
, 0);
360 /* -----------------------------------------------------------------------------
361 * Clocks and timestamps
364 static inline void uvc_video_get_ts(struct timespec
*ts
)
366 if (uvc_clock_param
== CLOCK_MONOTONIC
)
369 ktime_get_real_ts(ts
);
373 uvc_video_clock_decode(struct uvc_streaming
*stream
, struct uvc_buffer
*buf
,
374 const __u8
*data
, int len
)
376 struct uvc_clock_sample
*sample
;
377 unsigned int header_size
;
378 bool has_pts
= false;
379 bool has_scr
= false;
385 switch (data
[1] & (UVC_STREAM_PTS
| UVC_STREAM_SCR
)) {
386 case UVC_STREAM_PTS
| UVC_STREAM_SCR
:
404 /* Check for invalid headers. */
405 if (len
< header_size
)
408 /* Extract the timestamps:
410 * - store the frame PTS in the buffer structure
411 * - if the SCR field is present, retrieve the host SOF counter and
412 * kernel timestamps and store them with the SCR STC and SOF fields
415 if (has_pts
&& buf
!= NULL
)
416 buf
->pts
= get_unaligned_le32(&data
[2]);
421 /* To limit the amount of data, drop SCRs with an SOF identical to the
424 dev_sof
= get_unaligned_le16(&data
[header_size
- 2]);
425 if (dev_sof
== stream
->clock
.last_sof
)
428 stream
->clock
.last_sof
= dev_sof
;
430 host_sof
= usb_get_current_frame_number(stream
->dev
->udev
);
431 uvc_video_get_ts(&ts
);
433 /* The UVC specification allows device implementations that can't obtain
434 * the USB frame number to keep their own frame counters as long as they
435 * match the size and frequency of the frame number associated with USB
436 * SOF tokens. The SOF values sent by such devices differ from the USB
437 * SOF tokens by a fixed offset that needs to be estimated and accounted
438 * for to make timestamp recovery as accurate as possible.
440 * The offset is estimated the first time a device SOF value is received
441 * as the difference between the host and device SOF values. As the two
442 * SOF values can differ slightly due to transmission delays, consider
443 * that the offset is null if the difference is not higher than 10 ms
444 * (negative differences can not happen and are thus considered as an
445 * offset). The video commit control wDelay field should be used to
446 * compute a dynamic threshold instead of using a fixed 10 ms value, but
447 * devices don't report reliable wDelay values.
449 * See uvc_video_clock_host_sof() for an explanation regarding why only
450 * the 8 LSBs of the delta are kept.
452 if (stream
->clock
.sof_offset
== (u16
)-1) {
453 u16 delta_sof
= (host_sof
- dev_sof
) & 255;
455 stream
->clock
.sof_offset
= delta_sof
;
457 stream
->clock
.sof_offset
= 0;
460 dev_sof
= (dev_sof
+ stream
->clock
.sof_offset
) & 2047;
462 spin_lock_irqsave(&stream
->clock
.lock
, flags
);
464 sample
= &stream
->clock
.samples
[stream
->clock
.head
];
465 sample
->dev_stc
= get_unaligned_le32(&data
[header_size
- 6]);
466 sample
->dev_sof
= dev_sof
;
467 sample
->host_sof
= host_sof
;
468 sample
->host_ts
= ts
;
470 /* Update the sliding window head and count. */
471 stream
->clock
.head
= (stream
->clock
.head
+ 1) % stream
->clock
.size
;
473 if (stream
->clock
.count
< stream
->clock
.size
)
474 stream
->clock
.count
++;
476 spin_unlock_irqrestore(&stream
->clock
.lock
, flags
);
479 static void uvc_video_clock_reset(struct uvc_streaming
*stream
)
481 struct uvc_clock
*clock
= &stream
->clock
;
485 clock
->last_sof
= -1;
486 clock
->sof_offset
= -1;
489 static int uvc_video_clock_init(struct uvc_streaming
*stream
)
491 struct uvc_clock
*clock
= &stream
->clock
;
493 spin_lock_init(&clock
->lock
);
496 clock
->samples
= kmalloc(clock
->size
* sizeof(*clock
->samples
),
498 if (clock
->samples
== NULL
)
501 uvc_video_clock_reset(stream
);
506 static void uvc_video_clock_cleanup(struct uvc_streaming
*stream
)
508 kfree(stream
->clock
.samples
);
509 stream
->clock
.samples
= NULL
;
513 * uvc_video_clock_host_sof - Return the host SOF value for a clock sample
515 * Host SOF counters reported by usb_get_current_frame_number() usually don't
516 * cover the whole 11-bits SOF range (0-2047) but are limited to the HCI frame
517 * schedule window. They can be limited to 8, 9 or 10 bits depending on the host
518 * controller and its configuration.
520 * We thus need to recover the SOF value corresponding to the host frame number.
521 * As the device and host frame numbers are sampled in a short interval, the
522 * difference between their values should be equal to a small delta plus an
523 * integer multiple of 256 caused by the host frame number limited precision.
525 * To obtain the recovered host SOF value, compute the small delta by masking
526 * the high bits of the host frame counter and device SOF difference and add it
527 * to the device SOF value.
529 static u16
uvc_video_clock_host_sof(const struct uvc_clock_sample
*sample
)
531 /* The delta value can be negative. */
534 delta_sof
= (sample
->host_sof
- sample
->dev_sof
) & 255;
536 return (sample
->dev_sof
+ delta_sof
) & 2047;
540 * uvc_video_clock_update - Update the buffer timestamp
542 * This function converts the buffer PTS timestamp to the host clock domain by
543 * going through the USB SOF clock domain and stores the result in the V4L2
544 * buffer timestamp field.
546 * The relationship between the device clock and the host clock isn't known.
547 * However, the device and the host share the common USB SOF clock which can be
548 * used to recover that relationship.
550 * The relationship between the device clock and the USB SOF clock is considered
551 * to be linear over the clock samples sliding window and is given by
555 * Several methods to compute the slope (m) and intercept (p) can be used. As
556 * the clock drift should be small compared to the sliding window size, we
557 * assume that the line that goes through the points at both ends of the window
558 * is a good approximation. Naming those points P1 and P2, we get
560 * SOF = (SOF2 - SOF1) / (STC2 - STC1) * PTS
561 * + (SOF1 * STC2 - SOF2 * STC1) / (STC2 - STC1)
565 * SOF = ((SOF2 - SOF1) * PTS + SOF1 * STC2 - SOF2 * STC1) / (STC2 - STC1) (1)
567 * to avoid losing precision in the division. Similarly, the host timestamp is
570 * TS = ((TS2 - TS1) * PTS + TS1 * SOF2 - TS2 * SOF1) / (SOF2 - SOF1) (2)
572 * SOF values are coded on 11 bits by USB. We extend their precision with 16
573 * decimal bits, leading to a 11.16 coding.
575 * TODO: To avoid surprises with device clock values, PTS/STC timestamps should
576 * be normalized using the nominal device clock frequency reported through the
579 * Both the PTS/STC and SOF counters roll over, after a fixed but device
580 * specific amount of time for PTS/STC and after 2048ms for SOF. As long as the
581 * sliding window size is smaller than the rollover period, differences computed
582 * on unsigned integers will produce the correct result. However, the p term in
583 * the linear relations will be miscomputed.
585 * To fix the issue, we subtract a constant from the PTS and STC values to bring
586 * PTS to half the 32 bit STC range. The sliding window STC values then fit into
587 * the 32 bit range without any rollover.
589 * Similarly, we add 2048 to the device SOF values to make sure that the SOF
590 * computed by (1) will never be smaller than 0. This offset is then compensated
591 * by adding 2048 to the SOF values used in (2). However, this doesn't prevent
592 * rollovers between (1) and (2): the SOF value computed by (1) can be slightly
593 * lower than 4096, and the host SOF counters can have rolled over to 2048. This
594 * case is handled by subtracting 2048 from the SOF value if it exceeds the host
595 * SOF value at the end of the sliding window.
597 * Finally we subtract a constant from the host timestamps to bring the first
598 * timestamp of the sliding window to 1s.
600 void uvc_video_clock_update(struct uvc_streaming
*stream
,
601 struct v4l2_buffer
*v4l2_buf
,
602 struct uvc_buffer
*buf
)
604 struct uvc_clock
*clock
= &stream
->clock
;
605 struct uvc_clock_sample
*first
;
606 struct uvc_clock_sample
*last
;
618 spin_lock_irqsave(&clock
->lock
, flags
);
620 if (clock
->count
< clock
->size
)
623 first
= &clock
->samples
[clock
->head
];
624 last
= &clock
->samples
[(clock
->head
- 1) % clock
->size
];
626 /* First step, PTS to SOF conversion. */
627 delta_stc
= buf
->pts
- (1UL << 31);
628 x1
= first
->dev_stc
- delta_stc
;
629 x2
= last
->dev_stc
- delta_stc
;
633 y1
= (first
->dev_sof
+ 2048) << 16;
634 y2
= (last
->dev_sof
+ 2048) << 16;
638 y
= (u64
)(y2
- y1
) * (1ULL << 31) + (u64
)y1
* (u64
)x2
640 y
= div_u64(y
, x2
- x1
);
644 uvc_trace(UVC_TRACE_CLOCK
, "%s: PTS %u y %llu.%06llu SOF %u.%06llu "
645 "(x1 %u x2 %u y1 %u y2 %u SOF offset %u)\n",
646 stream
->dev
->name
, buf
->pts
,
647 y
>> 16, div_u64((y
& 0xffff) * 1000000, 65536),
648 sof
>> 16, div_u64(((u64
)sof
& 0xffff) * 1000000LLU, 65536),
649 x1
, x2
, y1
, y2
, clock
->sof_offset
);
651 /* Second step, SOF to host clock conversion. */
652 x1
= (uvc_video_clock_host_sof(first
) + 2048) << 16;
653 x2
= (uvc_video_clock_host_sof(last
) + 2048) << 16;
659 ts
= timespec_sub(last
->host_ts
, first
->host_ts
);
661 y2
= (ts
.tv_sec
+ 1) * NSEC_PER_SEC
+ ts
.tv_nsec
;
663 /* Interpolated and host SOF timestamps can wrap around at slightly
664 * different times. Handle this by adding or removing 2048 to or from
665 * the computed SOF value to keep it close to the SOF samples mean
668 mean
= (x1
+ x2
) / 2;
669 if (mean
- (1024 << 16) > sof
)
671 else if (sof
> mean
+ (1024 << 16))
674 y
= (u64
)(y2
- y1
) * (u64
)sof
+ (u64
)y1
* (u64
)x2
676 y
= div_u64(y
, x2
- x1
);
678 div
= div_u64_rem(y
, NSEC_PER_SEC
, &rem
);
679 ts
.tv_sec
= first
->host_ts
.tv_sec
- 1 + div
;
680 ts
.tv_nsec
= first
->host_ts
.tv_nsec
+ rem
;
681 if (ts
.tv_nsec
>= NSEC_PER_SEC
) {
683 ts
.tv_nsec
-= NSEC_PER_SEC
;
686 uvc_trace(UVC_TRACE_CLOCK
, "%s: SOF %u.%06llu y %llu ts %lu.%06lu "
687 "buf ts %lu.%06lu (x1 %u/%u/%u x2 %u/%u/%u y1 %u y2 %u)\n",
689 sof
>> 16, div_u64(((u64
)sof
& 0xffff) * 1000000LLU, 65536),
690 y
, ts
.tv_sec
, ts
.tv_nsec
/ NSEC_PER_USEC
,
691 v4l2_buf
->timestamp
.tv_sec
,
692 (unsigned long)v4l2_buf
->timestamp
.tv_usec
,
693 x1
, first
->host_sof
, first
->dev_sof
,
694 x2
, last
->host_sof
, last
->dev_sof
, y1
, y2
);
696 /* Update the V4L2 buffer. */
697 v4l2_buf
->timestamp
.tv_sec
= ts
.tv_sec
;
698 v4l2_buf
->timestamp
.tv_usec
= ts
.tv_nsec
/ NSEC_PER_USEC
;
701 spin_unlock_irqrestore(&stream
->clock
.lock
, flags
);
704 /* ------------------------------------------------------------------------
708 static void uvc_video_stats_decode(struct uvc_streaming
*stream
,
709 const __u8
*data
, int len
)
711 unsigned int header_size
;
712 bool has_pts
= false;
713 bool has_scr
= false;
714 u16
uninitialized_var(scr_sof
);
715 u32
uninitialized_var(scr_stc
);
716 u32
uninitialized_var(pts
);
718 if (stream
->stats
.stream
.nb_frames
== 0 &&
719 stream
->stats
.frame
.nb_packets
== 0)
720 ktime_get_ts(&stream
->stats
.stream
.start_ts
);
722 switch (data
[1] & (UVC_STREAM_PTS
| UVC_STREAM_SCR
)) {
723 case UVC_STREAM_PTS
| UVC_STREAM_SCR
:
741 /* Check for invalid headers. */
742 if (len
< header_size
|| data
[0] < header_size
) {
743 stream
->stats
.frame
.nb_invalid
++;
747 /* Extract the timestamps. */
749 pts
= get_unaligned_le32(&data
[2]);
752 scr_stc
= get_unaligned_le32(&data
[header_size
- 6]);
753 scr_sof
= get_unaligned_le16(&data
[header_size
- 2]);
756 /* Is PTS constant through the whole frame ? */
757 if (has_pts
&& stream
->stats
.frame
.nb_pts
) {
758 if (stream
->stats
.frame
.pts
!= pts
) {
759 stream
->stats
.frame
.nb_pts_diffs
++;
760 stream
->stats
.frame
.last_pts_diff
=
761 stream
->stats
.frame
.nb_packets
;
766 stream
->stats
.frame
.nb_pts
++;
767 stream
->stats
.frame
.pts
= pts
;
770 /* Do all frames have a PTS in their first non-empty packet, or before
771 * their first empty packet ?
773 if (stream
->stats
.frame
.size
== 0) {
774 if (len
> header_size
)
775 stream
->stats
.frame
.has_initial_pts
= has_pts
;
776 if (len
== header_size
&& has_pts
)
777 stream
->stats
.frame
.has_early_pts
= true;
780 /* Do the SCR.STC and SCR.SOF fields vary through the frame ? */
781 if (has_scr
&& stream
->stats
.frame
.nb_scr
) {
782 if (stream
->stats
.frame
.scr_stc
!= scr_stc
)
783 stream
->stats
.frame
.nb_scr_diffs
++;
787 /* Expand the SOF counter to 32 bits and store its value. */
788 if (stream
->stats
.stream
.nb_frames
> 0 ||
789 stream
->stats
.frame
.nb_scr
> 0)
790 stream
->stats
.stream
.scr_sof_count
+=
791 (scr_sof
- stream
->stats
.stream
.scr_sof
) % 2048;
792 stream
->stats
.stream
.scr_sof
= scr_sof
;
794 stream
->stats
.frame
.nb_scr
++;
795 stream
->stats
.frame
.scr_stc
= scr_stc
;
796 stream
->stats
.frame
.scr_sof
= scr_sof
;
798 if (scr_sof
< stream
->stats
.stream
.min_sof
)
799 stream
->stats
.stream
.min_sof
= scr_sof
;
800 if (scr_sof
> stream
->stats
.stream
.max_sof
)
801 stream
->stats
.stream
.max_sof
= scr_sof
;
804 /* Record the first non-empty packet number. */
805 if (stream
->stats
.frame
.size
== 0 && len
> header_size
)
806 stream
->stats
.frame
.first_data
= stream
->stats
.frame
.nb_packets
;
808 /* Update the frame size. */
809 stream
->stats
.frame
.size
+= len
- header_size
;
811 /* Update the packets counters. */
812 stream
->stats
.frame
.nb_packets
++;
813 if (len
> header_size
)
814 stream
->stats
.frame
.nb_empty
++;
816 if (data
[1] & UVC_STREAM_ERR
)
817 stream
->stats
.frame
.nb_errors
++;
820 static void uvc_video_stats_update(struct uvc_streaming
*stream
)
822 struct uvc_stats_frame
*frame
= &stream
->stats
.frame
;
824 uvc_trace(UVC_TRACE_STATS
, "frame %u stats: %u/%u/%u packets, "
825 "%u/%u/%u pts (%searly %sinitial), %u/%u scr, "
826 "last pts/stc/sof %u/%u/%u\n",
827 stream
->sequence
, frame
->first_data
,
828 frame
->nb_packets
- frame
->nb_empty
, frame
->nb_packets
,
829 frame
->nb_pts_diffs
, frame
->last_pts_diff
, frame
->nb_pts
,
830 frame
->has_early_pts
? "" : "!",
831 frame
->has_initial_pts
? "" : "!",
832 frame
->nb_scr_diffs
, frame
->nb_scr
,
833 frame
->pts
, frame
->scr_stc
, frame
->scr_sof
);
835 stream
->stats
.stream
.nb_frames
++;
836 stream
->stats
.stream
.nb_packets
+= stream
->stats
.frame
.nb_packets
;
837 stream
->stats
.stream
.nb_empty
+= stream
->stats
.frame
.nb_empty
;
838 stream
->stats
.stream
.nb_errors
+= stream
->stats
.frame
.nb_errors
;
839 stream
->stats
.stream
.nb_invalid
+= stream
->stats
.frame
.nb_invalid
;
841 if (frame
->has_early_pts
)
842 stream
->stats
.stream
.nb_pts_early
++;
843 if (frame
->has_initial_pts
)
844 stream
->stats
.stream
.nb_pts_initial
++;
845 if (frame
->last_pts_diff
<= frame
->first_data
)
846 stream
->stats
.stream
.nb_pts_constant
++;
847 if (frame
->nb_scr
>= frame
->nb_packets
- frame
->nb_empty
)
848 stream
->stats
.stream
.nb_scr_count_ok
++;
849 if (frame
->nb_scr_diffs
+ 1 == frame
->nb_scr
)
850 stream
->stats
.stream
.nb_scr_diffs_ok
++;
852 memset(&stream
->stats
.frame
, 0, sizeof(stream
->stats
.frame
));
855 size_t uvc_video_stats_dump(struct uvc_streaming
*stream
, char *buf
,
858 unsigned int scr_sof_freq
;
859 unsigned int duration
;
863 ts
.tv_sec
= stream
->stats
.stream
.stop_ts
.tv_sec
864 - stream
->stats
.stream
.start_ts
.tv_sec
;
865 ts
.tv_nsec
= stream
->stats
.stream
.stop_ts
.tv_nsec
866 - stream
->stats
.stream
.start_ts
.tv_nsec
;
867 if (ts
.tv_nsec
< 0) {
869 ts
.tv_nsec
+= 1000000000;
872 /* Compute the SCR.SOF frequency estimate. At the nominal 1kHz SOF
873 * frequency this will not overflow before more than 1h.
875 duration
= ts
.tv_sec
* 1000 + ts
.tv_nsec
/ 1000000;
877 scr_sof_freq
= stream
->stats
.stream
.scr_sof_count
* 1000
882 count
+= scnprintf(buf
+ count
, size
- count
,
883 "frames: %u\npackets: %u\nempty: %u\n"
884 "errors: %u\ninvalid: %u\n",
885 stream
->stats
.stream
.nb_frames
,
886 stream
->stats
.stream
.nb_packets
,
887 stream
->stats
.stream
.nb_empty
,
888 stream
->stats
.stream
.nb_errors
,
889 stream
->stats
.stream
.nb_invalid
);
890 count
+= scnprintf(buf
+ count
, size
- count
,
891 "pts: %u early, %u initial, %u ok\n",
892 stream
->stats
.stream
.nb_pts_early
,
893 stream
->stats
.stream
.nb_pts_initial
,
894 stream
->stats
.stream
.nb_pts_constant
);
895 count
+= scnprintf(buf
+ count
, size
- count
,
896 "scr: %u count ok, %u diff ok\n",
897 stream
->stats
.stream
.nb_scr_count_ok
,
898 stream
->stats
.stream
.nb_scr_diffs_ok
);
899 count
+= scnprintf(buf
+ count
, size
- count
,
900 "sof: %u <= sof <= %u, freq %u.%03u kHz\n",
901 stream
->stats
.stream
.min_sof
,
902 stream
->stats
.stream
.max_sof
,
903 scr_sof_freq
/ 1000, scr_sof_freq
% 1000);
908 static void uvc_video_stats_start(struct uvc_streaming
*stream
)
910 memset(&stream
->stats
, 0, sizeof(stream
->stats
));
911 stream
->stats
.stream
.min_sof
= 2048;
914 static void uvc_video_stats_stop(struct uvc_streaming
*stream
)
916 ktime_get_ts(&stream
->stats
.stream
.stop_ts
);
919 /* ------------------------------------------------------------------------
923 /* Video payload decoding is handled by uvc_video_decode_start(),
924 * uvc_video_decode_data() and uvc_video_decode_end().
926 * uvc_video_decode_start is called with URB data at the start of a bulk or
927 * isochronous payload. It processes header data and returns the header size
928 * in bytes if successful. If an error occurs, it returns a negative error
929 * code. The following error codes have special meanings.
931 * - EAGAIN informs the caller that the current video buffer should be marked
932 * as done, and that the function should be called again with the same data
933 * and a new video buffer. This is used when end of frame conditions can be
934 * reliably detected at the beginning of the next frame only.
936 * If an error other than -EAGAIN is returned, the caller will drop the current
937 * payload. No call to uvc_video_decode_data and uvc_video_decode_end will be
938 * made until the next payload. -ENODATA can be used to drop the current
939 * payload if no other error code is appropriate.
941 * uvc_video_decode_data is called for every URB with URB data. It copies the
942 * data to the video buffer.
944 * uvc_video_decode_end is called with header data at the end of a bulk or
945 * isochronous payload. It performs any additional header data processing and
946 * returns 0 or a negative error code if an error occurred. As header data have
947 * already been processed by uvc_video_decode_start, this functions isn't
948 * required to perform sanity checks a second time.
950 * For isochronous transfers where a payload is always transferred in a single
951 * URB, the three functions will be called in a row.
953 * To let the decoder process header data and update its internal state even
954 * when no video buffer is available, uvc_video_decode_start must be prepared
955 * to be called with a NULL buf parameter. uvc_video_decode_data and
956 * uvc_video_decode_end will never be called with a NULL buffer.
958 static int uvc_video_decode_start(struct uvc_streaming
*stream
,
959 struct uvc_buffer
*buf
, const __u8
*data
, int len
)
964 * - packet must be at least 2 bytes long
965 * - bHeaderLength value must be at least 2 bytes (see above)
966 * - bHeaderLength value can't be larger than the packet size.
968 if (len
< 2 || data
[0] < 2 || data
[0] > len
) {
969 stream
->stats
.frame
.nb_invalid
++;
973 fid
= data
[1] & UVC_STREAM_FID
;
975 /* Increase the sequence number regardless of any buffer states, so
976 * that discontinuous sequence numbers always indicate lost frames.
978 if (stream
->last_fid
!= fid
) {
980 if (stream
->sequence
)
981 uvc_video_stats_update(stream
);
984 uvc_video_clock_decode(stream
, buf
, data
, len
);
985 uvc_video_stats_decode(stream
, data
, len
);
987 /* Store the payload FID bit and return immediately when the buffer is
991 stream
->last_fid
= fid
;
995 /* Mark the buffer as bad if the error bit is set. */
996 if (data
[1] & UVC_STREAM_ERR
) {
997 uvc_trace(UVC_TRACE_FRAME
, "Marking buffer as bad (error bit "
1002 /* Synchronize to the input stream by waiting for the FID bit to be
1003 * toggled when the the buffer state is not UVC_BUF_STATE_ACTIVE.
1004 * stream->last_fid is initialized to -1, so the first isochronous
1005 * frame will always be in sync.
1007 * If the device doesn't toggle the FID bit, invert stream->last_fid
1008 * when the EOF bit is set to force synchronisation on the next packet.
1010 if (buf
->state
!= UVC_BUF_STATE_ACTIVE
) {
1013 if (fid
== stream
->last_fid
) {
1014 uvc_trace(UVC_TRACE_FRAME
, "Dropping payload (out of "
1016 if ((stream
->dev
->quirks
& UVC_QUIRK_STREAM_NO_FID
) &&
1017 (data
[1] & UVC_STREAM_EOF
))
1018 stream
->last_fid
^= UVC_STREAM_FID
;
1022 uvc_video_get_ts(&ts
);
1024 buf
->buf
.v4l2_buf
.sequence
= stream
->sequence
;
1025 buf
->buf
.v4l2_buf
.timestamp
.tv_sec
= ts
.tv_sec
;
1026 buf
->buf
.v4l2_buf
.timestamp
.tv_usec
=
1027 ts
.tv_nsec
/ NSEC_PER_USEC
;
1029 /* TODO: Handle PTS and SCR. */
1030 buf
->state
= UVC_BUF_STATE_ACTIVE
;
1033 /* Mark the buffer as done if we're at the beginning of a new frame.
1034 * End of frame detection is better implemented by checking the EOF
1035 * bit (FID bit toggling is delayed by one frame compared to the EOF
1036 * bit), but some devices don't set the bit at end of frame (and the
1037 * last payload can be lost anyway). We thus must check if the FID has
1040 * stream->last_fid is initialized to -1, so the first isochronous
1041 * frame will never trigger an end of frame detection.
1043 * Empty buffers (bytesused == 0) don't trigger end of frame detection
1044 * as it doesn't make sense to return an empty buffer. This also
1045 * avoids detecting end of frame conditions at FID toggling if the
1046 * previous payload had the EOF bit set.
1048 if (fid
!= stream
->last_fid
&& buf
->bytesused
!= 0) {
1049 uvc_trace(UVC_TRACE_FRAME
, "Frame complete (FID bit "
1051 buf
->state
= UVC_BUF_STATE_READY
;
1055 stream
->last_fid
= fid
;
1060 static void uvc_video_decode_data(struct uvc_streaming
*stream
,
1061 struct uvc_buffer
*buf
, const __u8
*data
, int len
)
1063 unsigned int maxlen
, nbytes
;
1069 /* Copy the video data to the buffer. */
1070 maxlen
= buf
->length
- buf
->bytesused
;
1071 mem
= buf
->mem
+ buf
->bytesused
;
1072 nbytes
= min((unsigned int)len
, maxlen
);
1073 memcpy(mem
, data
, nbytes
);
1074 buf
->bytesused
+= nbytes
;
1076 /* Complete the current frame if the buffer size was exceeded. */
1078 uvc_trace(UVC_TRACE_FRAME
, "Frame complete (overflow).\n");
1079 buf
->state
= UVC_BUF_STATE_READY
;
1083 static void uvc_video_decode_end(struct uvc_streaming
*stream
,
1084 struct uvc_buffer
*buf
, const __u8
*data
, int len
)
1086 /* Mark the buffer as done if the EOF marker is set. */
1087 if (data
[1] & UVC_STREAM_EOF
&& buf
->bytesused
!= 0) {
1088 uvc_trace(UVC_TRACE_FRAME
, "Frame complete (EOF found).\n");
1090 uvc_trace(UVC_TRACE_FRAME
, "EOF in empty payload.\n");
1091 buf
->state
= UVC_BUF_STATE_READY
;
1092 if (stream
->dev
->quirks
& UVC_QUIRK_STREAM_NO_FID
)
1093 stream
->last_fid
^= UVC_STREAM_FID
;
1097 /* Video payload encoding is handled by uvc_video_encode_header() and
1098 * uvc_video_encode_data(). Only bulk transfers are currently supported.
1100 * uvc_video_encode_header is called at the start of a payload. It adds header
1101 * data to the transfer buffer and returns the header size. As the only known
1102 * UVC output device transfers a whole frame in a single payload, the EOF bit
1103 * is always set in the header.
1105 * uvc_video_encode_data is called for every URB and copies the data from the
1106 * video buffer to the transfer buffer.
1108 static int uvc_video_encode_header(struct uvc_streaming
*stream
,
1109 struct uvc_buffer
*buf
, __u8
*data
, int len
)
1111 data
[0] = 2; /* Header length */
1112 data
[1] = UVC_STREAM_EOH
| UVC_STREAM_EOF
1113 | (stream
->last_fid
& UVC_STREAM_FID
);
1117 static int uvc_video_encode_data(struct uvc_streaming
*stream
,
1118 struct uvc_buffer
*buf
, __u8
*data
, int len
)
1120 struct uvc_video_queue
*queue
= &stream
->queue
;
1121 unsigned int nbytes
;
1124 /* Copy video data to the URB buffer. */
1125 mem
= buf
->mem
+ queue
->buf_used
;
1126 nbytes
= min((unsigned int)len
, buf
->bytesused
- queue
->buf_used
);
1127 nbytes
= min(stream
->bulk
.max_payload_size
- stream
->bulk
.payload_size
,
1129 memcpy(data
, mem
, nbytes
);
1131 queue
->buf_used
+= nbytes
;
1136 /* ------------------------------------------------------------------------
1141 * Set error flag for incomplete buffer.
1143 static void uvc_video_validate_buffer(const struct uvc_streaming
*stream
,
1144 struct uvc_buffer
*buf
)
1146 if (stream
->frame_size
!= buf
->bytesused
&&
1147 !(stream
->cur_format
->flags
& UVC_FMT_FLAG_COMPRESSED
))
1152 * Completion handler for video URBs.
1154 static void uvc_video_decode_isoc(struct urb
*urb
, struct uvc_streaming
*stream
,
1155 struct uvc_buffer
*buf
)
1160 for (i
= 0; i
< urb
->number_of_packets
; ++i
) {
1161 if (urb
->iso_frame_desc
[i
].status
< 0) {
1162 uvc_trace(UVC_TRACE_FRAME
, "USB isochronous frame "
1163 "lost (%d).\n", urb
->iso_frame_desc
[i
].status
);
1164 /* Mark the buffer as faulty. */
1170 /* Decode the payload header. */
1171 mem
= urb
->transfer_buffer
+ urb
->iso_frame_desc
[i
].offset
;
1173 ret
= uvc_video_decode_start(stream
, buf
, mem
,
1174 urb
->iso_frame_desc
[i
].actual_length
);
1175 if (ret
== -EAGAIN
) {
1176 uvc_video_validate_buffer(stream
, buf
);
1177 buf
= uvc_queue_next_buffer(&stream
->queue
,
1180 } while (ret
== -EAGAIN
);
1185 /* Decode the payload data. */
1186 uvc_video_decode_data(stream
, buf
, mem
+ ret
,
1187 urb
->iso_frame_desc
[i
].actual_length
- ret
);
1189 /* Process the header again. */
1190 uvc_video_decode_end(stream
, buf
, mem
,
1191 urb
->iso_frame_desc
[i
].actual_length
);
1193 if (buf
->state
== UVC_BUF_STATE_READY
) {
1194 uvc_video_validate_buffer(stream
, buf
);
1195 buf
= uvc_queue_next_buffer(&stream
->queue
, buf
);
1200 static void uvc_video_decode_bulk(struct urb
*urb
, struct uvc_streaming
*stream
,
1201 struct uvc_buffer
*buf
)
1207 * Ignore ZLPs if they're not part of a frame, otherwise process them
1208 * to trigger the end of payload detection.
1210 if (urb
->actual_length
== 0 && stream
->bulk
.header_size
== 0)
1213 mem
= urb
->transfer_buffer
;
1214 len
= urb
->actual_length
;
1215 stream
->bulk
.payload_size
+= len
;
1217 /* If the URB is the first of its payload, decode and save the
1220 if (stream
->bulk
.header_size
== 0 && !stream
->bulk
.skip_payload
) {
1222 ret
= uvc_video_decode_start(stream
, buf
, mem
, len
);
1224 buf
= uvc_queue_next_buffer(&stream
->queue
,
1226 } while (ret
== -EAGAIN
);
1228 /* If an error occurred skip the rest of the payload. */
1229 if (ret
< 0 || buf
== NULL
) {
1230 stream
->bulk
.skip_payload
= 1;
1232 memcpy(stream
->bulk
.header
, mem
, ret
);
1233 stream
->bulk
.header_size
= ret
;
1240 /* The buffer queue might have been cancelled while a bulk transfer
1241 * was in progress, so we can reach here with buf equal to NULL. Make
1242 * sure buf is never dereferenced if NULL.
1245 /* Process video data. */
1246 if (!stream
->bulk
.skip_payload
&& buf
!= NULL
)
1247 uvc_video_decode_data(stream
, buf
, mem
, len
);
1249 /* Detect the payload end by a URB smaller than the maximum size (or
1250 * a payload size equal to the maximum) and process the header again.
1252 if (urb
->actual_length
< urb
->transfer_buffer_length
||
1253 stream
->bulk
.payload_size
>= stream
->bulk
.max_payload_size
) {
1254 if (!stream
->bulk
.skip_payload
&& buf
!= NULL
) {
1255 uvc_video_decode_end(stream
, buf
, stream
->bulk
.header
,
1256 stream
->bulk
.payload_size
);
1257 if (buf
->state
== UVC_BUF_STATE_READY
)
1258 buf
= uvc_queue_next_buffer(&stream
->queue
,
1262 stream
->bulk
.header_size
= 0;
1263 stream
->bulk
.skip_payload
= 0;
1264 stream
->bulk
.payload_size
= 0;
1268 static void uvc_video_encode_bulk(struct urb
*urb
, struct uvc_streaming
*stream
,
1269 struct uvc_buffer
*buf
)
1271 u8
*mem
= urb
->transfer_buffer
;
1272 int len
= stream
->urb_size
, ret
;
1275 urb
->transfer_buffer_length
= 0;
1279 /* If the URB is the first of its payload, add the header. */
1280 if (stream
->bulk
.header_size
== 0) {
1281 ret
= uvc_video_encode_header(stream
, buf
, mem
, len
);
1282 stream
->bulk
.header_size
= ret
;
1283 stream
->bulk
.payload_size
+= ret
;
1288 /* Process video data. */
1289 ret
= uvc_video_encode_data(stream
, buf
, mem
, len
);
1291 stream
->bulk
.payload_size
+= ret
;
1294 if (buf
->bytesused
== stream
->queue
.buf_used
||
1295 stream
->bulk
.payload_size
== stream
->bulk
.max_payload_size
) {
1296 if (buf
->bytesused
== stream
->queue
.buf_used
) {
1297 stream
->queue
.buf_used
= 0;
1298 buf
->state
= UVC_BUF_STATE_READY
;
1299 buf
->buf
.v4l2_buf
.sequence
= ++stream
->sequence
;
1300 uvc_queue_next_buffer(&stream
->queue
, buf
);
1301 stream
->last_fid
^= UVC_STREAM_FID
;
1304 stream
->bulk
.header_size
= 0;
1305 stream
->bulk
.payload_size
= 0;
1308 urb
->transfer_buffer_length
= stream
->urb_size
- len
;
1311 static void uvc_video_complete(struct urb
*urb
)
1313 struct uvc_streaming
*stream
= urb
->context
;
1314 struct uvc_video_queue
*queue
= &stream
->queue
;
1315 struct uvc_buffer
*buf
= NULL
;
1316 unsigned long flags
;
1319 switch (urb
->status
) {
1324 uvc_printk(KERN_WARNING
, "Non-zero status (%d) in video "
1325 "completion handler.\n", urb
->status
);
1327 case -ENOENT
: /* usb_kill_urb() called. */
1331 case -ECONNRESET
: /* usb_unlink_urb() called. */
1332 case -ESHUTDOWN
: /* The endpoint is being disabled. */
1333 uvc_queue_cancel(queue
, urb
->status
== -ESHUTDOWN
);
1337 spin_lock_irqsave(&queue
->irqlock
, flags
);
1338 if (!list_empty(&queue
->irqqueue
))
1339 buf
= list_first_entry(&queue
->irqqueue
, struct uvc_buffer
,
1341 spin_unlock_irqrestore(&queue
->irqlock
, flags
);
1343 stream
->decode(urb
, stream
, buf
);
1345 if ((ret
= usb_submit_urb(urb
, GFP_ATOMIC
)) < 0) {
1346 uvc_printk(KERN_ERR
, "Failed to resubmit video URB (%d).\n",
1352 * Free transfer buffers.
1354 static void uvc_free_urb_buffers(struct uvc_streaming
*stream
)
1358 for (i
= 0; i
< UVC_URBS
; ++i
) {
1359 if (stream
->urb_buffer
[i
]) {
1360 #ifndef CONFIG_DMA_NONCOHERENT
1361 usb_free_coherent(stream
->dev
->udev
, stream
->urb_size
,
1362 stream
->urb_buffer
[i
], stream
->urb_dma
[i
]);
1364 kfree(stream
->urb_buffer
[i
]);
1366 stream
->urb_buffer
[i
] = NULL
;
1370 stream
->urb_size
= 0;
1374 * Allocate transfer buffers. This function can be called with buffers
1375 * already allocated when resuming from suspend, in which case it will
1376 * return without touching the buffers.
1378 * Limit the buffer size to UVC_MAX_PACKETS bulk/isochronous packets. If the
1379 * system is too low on memory try successively smaller numbers of packets
1380 * until allocation succeeds.
1382 * Return the number of allocated packets on success or 0 when out of memory.
1384 static int uvc_alloc_urb_buffers(struct uvc_streaming
*stream
,
1385 unsigned int size
, unsigned int psize
, gfp_t gfp_flags
)
1387 unsigned int npackets
;
1390 /* Buffers are already allocated, bail out. */
1391 if (stream
->urb_size
)
1392 return stream
->urb_size
/ psize
;
1394 /* Compute the number of packets. Bulk endpoints might transfer UVC
1395 * payloads across multiple URBs.
1397 npackets
= DIV_ROUND_UP(size
, psize
);
1398 if (npackets
> UVC_MAX_PACKETS
)
1399 npackets
= UVC_MAX_PACKETS
;
1401 /* Retry allocations until one succeed. */
1402 for (; npackets
> 1; npackets
/= 2) {
1403 for (i
= 0; i
< UVC_URBS
; ++i
) {
1404 stream
->urb_size
= psize
* npackets
;
1405 #ifndef CONFIG_DMA_NONCOHERENT
1406 stream
->urb_buffer
[i
] = usb_alloc_coherent(
1407 stream
->dev
->udev
, stream
->urb_size
,
1408 gfp_flags
| __GFP_NOWARN
, &stream
->urb_dma
[i
]);
1410 stream
->urb_buffer
[i
] =
1411 kmalloc(stream
->urb_size
, gfp_flags
| __GFP_NOWARN
);
1413 if (!stream
->urb_buffer
[i
]) {
1414 uvc_free_urb_buffers(stream
);
1419 if (i
== UVC_URBS
) {
1420 uvc_trace(UVC_TRACE_VIDEO
, "Allocated %u URB buffers "
1421 "of %ux%u bytes each.\n", UVC_URBS
, npackets
,
1427 uvc_trace(UVC_TRACE_VIDEO
, "Failed to allocate URB buffers (%u bytes "
1428 "per packet).\n", psize
);
1433 * Uninitialize isochronous/bulk URBs and free transfer buffers.
1435 static void uvc_uninit_video(struct uvc_streaming
*stream
, int free_buffers
)
1440 uvc_video_stats_stop(stream
);
1442 for (i
= 0; i
< UVC_URBS
; ++i
) {
1443 urb
= stream
->urb
[i
];
1449 stream
->urb
[i
] = NULL
;
1453 uvc_free_urb_buffers(stream
);
1457 * Compute the maximum number of bytes per interval for an endpoint.
1459 static unsigned int uvc_endpoint_max_bpi(struct usb_device
*dev
,
1460 struct usb_host_endpoint
*ep
)
1464 switch (dev
->speed
) {
1465 case USB_SPEED_SUPER
:
1466 return le16_to_cpu(ep
->ss_ep_comp
.wBytesPerInterval
);
1467 case USB_SPEED_HIGH
:
1468 psize
= usb_endpoint_maxp(&ep
->desc
);
1469 return (psize
& 0x07ff) * (1 + ((psize
>> 11) & 3));
1470 case USB_SPEED_WIRELESS
:
1471 psize
= usb_endpoint_maxp(&ep
->desc
);
1474 psize
= usb_endpoint_maxp(&ep
->desc
);
1475 return psize
& 0x07ff;
1480 * Initialize isochronous URBs and allocate transfer buffers. The packet size
1481 * is given by the endpoint.
1483 static int uvc_init_video_isoc(struct uvc_streaming
*stream
,
1484 struct usb_host_endpoint
*ep
, gfp_t gfp_flags
)
1487 unsigned int npackets
, i
, j
;
1491 psize
= uvc_endpoint_max_bpi(stream
->dev
->udev
, ep
);
1492 size
= stream
->ctrl
.dwMaxVideoFrameSize
;
1494 npackets
= uvc_alloc_urb_buffers(stream
, size
, psize
, gfp_flags
);
1498 size
= npackets
* psize
;
1500 for (i
= 0; i
< UVC_URBS
; ++i
) {
1501 urb
= usb_alloc_urb(npackets
, gfp_flags
);
1503 uvc_uninit_video(stream
, 1);
1507 urb
->dev
= stream
->dev
->udev
;
1508 urb
->context
= stream
;
1509 urb
->pipe
= usb_rcvisocpipe(stream
->dev
->udev
,
1510 ep
->desc
.bEndpointAddress
);
1511 #ifndef CONFIG_DMA_NONCOHERENT
1512 urb
->transfer_flags
= URB_ISO_ASAP
| URB_NO_TRANSFER_DMA_MAP
;
1513 urb
->transfer_dma
= stream
->urb_dma
[i
];
1515 urb
->transfer_flags
= URB_ISO_ASAP
;
1517 urb
->interval
= ep
->desc
.bInterval
;
1518 urb
->transfer_buffer
= stream
->urb_buffer
[i
];
1519 urb
->complete
= uvc_video_complete
;
1520 urb
->number_of_packets
= npackets
;
1521 urb
->transfer_buffer_length
= size
;
1523 for (j
= 0; j
< npackets
; ++j
) {
1524 urb
->iso_frame_desc
[j
].offset
= j
* psize
;
1525 urb
->iso_frame_desc
[j
].length
= psize
;
1528 stream
->urb
[i
] = urb
;
1535 * Initialize bulk URBs and allocate transfer buffers. The packet size is
1536 * given by the endpoint.
1538 static int uvc_init_video_bulk(struct uvc_streaming
*stream
,
1539 struct usb_host_endpoint
*ep
, gfp_t gfp_flags
)
1542 unsigned int npackets
, pipe
, i
;
1546 psize
= usb_endpoint_maxp(&ep
->desc
) & 0x7ff;
1547 size
= stream
->ctrl
.dwMaxPayloadTransferSize
;
1548 stream
->bulk
.max_payload_size
= size
;
1550 npackets
= uvc_alloc_urb_buffers(stream
, size
, psize
, gfp_flags
);
1554 size
= npackets
* psize
;
1556 if (usb_endpoint_dir_in(&ep
->desc
))
1557 pipe
= usb_rcvbulkpipe(stream
->dev
->udev
,
1558 ep
->desc
.bEndpointAddress
);
1560 pipe
= usb_sndbulkpipe(stream
->dev
->udev
,
1561 ep
->desc
.bEndpointAddress
);
1563 if (stream
->type
== V4L2_BUF_TYPE_VIDEO_OUTPUT
)
1566 for (i
= 0; i
< UVC_URBS
; ++i
) {
1567 urb
= usb_alloc_urb(0, gfp_flags
);
1569 uvc_uninit_video(stream
, 1);
1573 usb_fill_bulk_urb(urb
, stream
->dev
->udev
, pipe
,
1574 stream
->urb_buffer
[i
], size
, uvc_video_complete
,
1576 #ifndef CONFIG_DMA_NONCOHERENT
1577 urb
->transfer_flags
= URB_NO_TRANSFER_DMA_MAP
;
1578 urb
->transfer_dma
= stream
->urb_dma
[i
];
1581 stream
->urb
[i
] = urb
;
1588 * Initialize isochronous/bulk URBs and allocate transfer buffers.
1590 static int uvc_init_video(struct uvc_streaming
*stream
, gfp_t gfp_flags
)
1592 struct usb_interface
*intf
= stream
->intf
;
1593 struct usb_host_endpoint
*ep
;
1597 stream
->sequence
= -1;
1598 stream
->last_fid
= -1;
1599 stream
->bulk
.header_size
= 0;
1600 stream
->bulk
.skip_payload
= 0;
1601 stream
->bulk
.payload_size
= 0;
1603 uvc_video_stats_start(stream
);
1605 if (intf
->num_altsetting
> 1) {
1606 struct usb_host_endpoint
*best_ep
= NULL
;
1607 unsigned int best_psize
= UINT_MAX
;
1608 unsigned int bandwidth
;
1609 unsigned int uninitialized_var(altsetting
);
1610 int intfnum
= stream
->intfnum
;
1612 /* Isochronous endpoint, select the alternate setting. */
1613 bandwidth
= stream
->ctrl
.dwMaxPayloadTransferSize
;
1615 if (bandwidth
== 0) {
1616 uvc_trace(UVC_TRACE_VIDEO
, "Device requested null "
1617 "bandwidth, defaulting to lowest.\n");
1620 uvc_trace(UVC_TRACE_VIDEO
, "Device requested %u "
1621 "B/frame bandwidth.\n", bandwidth
);
1624 for (i
= 0; i
< intf
->num_altsetting
; ++i
) {
1625 struct usb_host_interface
*alts
;
1628 alts
= &intf
->altsetting
[i
];
1629 ep
= uvc_find_endpoint(alts
,
1630 stream
->header
.bEndpointAddress
);
1634 /* Check if the bandwidth is high enough. */
1635 psize
= uvc_endpoint_max_bpi(stream
->dev
->udev
, ep
);
1636 if (psize
>= bandwidth
&& psize
<= best_psize
) {
1637 altsetting
= alts
->desc
.bAlternateSetting
;
1643 if (best_ep
== NULL
) {
1644 uvc_trace(UVC_TRACE_VIDEO
, "No fast enough alt setting "
1645 "for requested bandwidth.\n");
1649 uvc_trace(UVC_TRACE_VIDEO
, "Selecting alternate setting %u "
1650 "(%u B/frame bandwidth).\n", altsetting
, best_psize
);
1652 ret
= usb_set_interface(stream
->dev
->udev
, intfnum
, altsetting
);
1656 ret
= uvc_init_video_isoc(stream
, best_ep
, gfp_flags
);
1658 /* Bulk endpoint, proceed to URB initialization. */
1659 ep
= uvc_find_endpoint(&intf
->altsetting
[0],
1660 stream
->header
.bEndpointAddress
);
1664 ret
= uvc_init_video_bulk(stream
, ep
, gfp_flags
);
1670 /* Submit the URBs. */
1671 for (i
= 0; i
< UVC_URBS
; ++i
) {
1672 ret
= usb_submit_urb(stream
->urb
[i
], gfp_flags
);
1674 uvc_printk(KERN_ERR
, "Failed to submit URB %u "
1676 uvc_uninit_video(stream
, 1);
1681 /* The Logitech C920 temporarily forgets that it should not be adjusting
1682 * Exposure Absolute during init so restore controls to stored values.
1684 if (stream
->dev
->quirks
& UVC_QUIRK_RESTORE_CTRLS_ON_INIT
)
1685 uvc_ctrl_restore_values(stream
->dev
);
1690 /* --------------------------------------------------------------------------
1695 * Stop streaming without disabling the video queue.
1697 * To let userspace applications resume without trouble, we must not touch the
1698 * video buffers in any way. We mark the device as frozen to make sure the URB
1699 * completion handler won't try to cancel the queue when we kill the URBs.
1701 int uvc_video_suspend(struct uvc_streaming
*stream
)
1703 if (!uvc_queue_streaming(&stream
->queue
))
1707 uvc_uninit_video(stream
, 0);
1708 usb_set_interface(stream
->dev
->udev
, stream
->intfnum
, 0);
1713 * Reconfigure the video interface and restart streaming if it was enabled
1716 * If an error occurs, disable the video queue. This will wake all pending
1717 * buffers, making sure userspace applications are notified of the problem
1718 * instead of waiting forever.
1720 int uvc_video_resume(struct uvc_streaming
*stream
, int reset
)
1724 /* If the bus has been reset on resume, set the alternate setting to 0.
1725 * This should be the default value, but some devices crash or otherwise
1726 * misbehave if they don't receive a SET_INTERFACE request before any
1727 * other video control request.
1730 usb_set_interface(stream
->dev
->udev
, stream
->intfnum
, 0);
1734 uvc_video_clock_reset(stream
);
1736 ret
= uvc_commit_video(stream
, &stream
->ctrl
);
1738 uvc_queue_enable(&stream
->queue
, 0);
1742 if (!uvc_queue_streaming(&stream
->queue
))
1745 ret
= uvc_init_video(stream
, GFP_NOIO
);
1747 uvc_queue_enable(&stream
->queue
, 0);
1752 /* ------------------------------------------------------------------------
1757 * Initialize the UVC video device by switching to alternate setting 0 and
1758 * retrieve the default format.
1760 * Some cameras (namely the Fuji Finepix) set the format and frame
1761 * indexes to zero. The UVC standard doesn't clearly make this a spec
1762 * violation, so try to silently fix the values if possible.
1764 * This function is called before registering the device with V4L.
1766 int uvc_video_init(struct uvc_streaming
*stream
)
1768 struct uvc_streaming_control
*probe
= &stream
->ctrl
;
1769 struct uvc_format
*format
= NULL
;
1770 struct uvc_frame
*frame
= NULL
;
1774 if (stream
->nformats
== 0) {
1775 uvc_printk(KERN_INFO
, "No supported video formats found.\n");
1779 atomic_set(&stream
->active
, 0);
1781 /* Initialize the video buffers queue. */
1782 ret
= uvc_queue_init(&stream
->queue
, stream
->type
, !uvc_no_drop_param
);
1786 /* Alternate setting 0 should be the default, yet the XBox Live Vision
1787 * Cam (and possibly other devices) crash or otherwise misbehave if
1788 * they don't receive a SET_INTERFACE request before any other video
1791 usb_set_interface(stream
->dev
->udev
, stream
->intfnum
, 0);
1793 /* Set the streaming probe control with default streaming parameters
1794 * retrieved from the device. Webcams that don't suport GET_DEF
1795 * requests on the probe control will just keep their current streaming
1798 if (uvc_get_video_ctrl(stream
, probe
, 1, UVC_GET_DEF
) == 0)
1799 uvc_set_video_ctrl(stream
, probe
, 1);
1801 /* Initialize the streaming parameters with the probe control current
1802 * value. This makes sure SET_CUR requests on the streaming commit
1803 * control will always use values retrieved from a successful GET_CUR
1804 * request on the probe control, as required by the UVC specification.
1806 ret
= uvc_get_video_ctrl(stream
, probe
, 1, UVC_GET_CUR
);
1810 /* Check if the default format descriptor exists. Use the first
1811 * available format otherwise.
1813 for (i
= stream
->nformats
; i
> 0; --i
) {
1814 format
= &stream
->format
[i
-1];
1815 if (format
->index
== probe
->bFormatIndex
)
1819 if (format
->nframes
== 0) {
1820 uvc_printk(KERN_INFO
, "No frame descriptor found for the "
1821 "default format.\n");
1825 /* Zero bFrameIndex might be correct. Stream-based formats (including
1826 * MPEG-2 TS and DV) do not support frames but have a dummy frame
1827 * descriptor with bFrameIndex set to zero. If the default frame
1828 * descriptor is not found, use the first available frame.
1830 for (i
= format
->nframes
; i
> 0; --i
) {
1831 frame
= &format
->frame
[i
-1];
1832 if (frame
->bFrameIndex
== probe
->bFrameIndex
)
1836 probe
->bFormatIndex
= format
->index
;
1837 probe
->bFrameIndex
= frame
->bFrameIndex
;
1839 stream
->def_format
= format
;
1840 stream
->cur_format
= format
;
1841 stream
->cur_frame
= frame
;
1843 /* Select the video decoding function */
1844 if (stream
->type
== V4L2_BUF_TYPE_VIDEO_CAPTURE
) {
1845 if (stream
->dev
->quirks
& UVC_QUIRK_BUILTIN_ISIGHT
)
1846 stream
->decode
= uvc_video_decode_isight
;
1847 else if (stream
->intf
->num_altsetting
> 1)
1848 stream
->decode
= uvc_video_decode_isoc
;
1850 stream
->decode
= uvc_video_decode_bulk
;
1852 if (stream
->intf
->num_altsetting
== 1)
1853 stream
->decode
= uvc_video_encode_bulk
;
1855 uvc_printk(KERN_INFO
, "Isochronous endpoints are not "
1856 "supported for video output devices.\n");
1865 * Enable or disable the video stream.
1867 int uvc_video_enable(struct uvc_streaming
*stream
, int enable
)
1872 uvc_uninit_video(stream
, 1);
1873 if (stream
->intf
->num_altsetting
> 1) {
1874 usb_set_interface(stream
->dev
->udev
,
1875 stream
->intfnum
, 0);
1877 /* UVC doesn't specify how to inform a bulk-based device
1878 * when the video stream is stopped. Windows sends a
1879 * CLEAR_FEATURE(HALT) request to the video streaming
1880 * bulk endpoint, mimic the same behaviour.
1882 unsigned int epnum
= stream
->header
.bEndpointAddress
1883 & USB_ENDPOINT_NUMBER_MASK
;
1884 unsigned int dir
= stream
->header
.bEndpointAddress
1885 & USB_ENDPOINT_DIR_MASK
;
1888 pipe
= usb_sndbulkpipe(stream
->dev
->udev
, epnum
) | dir
;
1889 usb_clear_halt(stream
->dev
->udev
, pipe
);
1892 uvc_queue_enable(&stream
->queue
, 0);
1893 uvc_video_clock_cleanup(stream
);
1897 ret
= uvc_video_clock_init(stream
);
1901 ret
= uvc_queue_enable(&stream
->queue
, 1);
1905 /* Commit the streaming parameters. */
1906 ret
= uvc_commit_video(stream
, &stream
->ctrl
);
1910 ret
= uvc_init_video(stream
, GFP_KERNEL
);
1917 usb_set_interface(stream
->dev
->udev
, stream
->intfnum
, 0);
1919 uvc_queue_enable(&stream
->queue
, 0);
1921 uvc_video_clock_cleanup(stream
);