2 * uvc_video.c -- USB Video Class driver - Video handling
4 * Copyright (C) 2005-2009
5 * Laurent Pinchart (laurent.pinchart@skynet.be)
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/usb.h>
18 #include <linux/videodev2.h>
19 #include <linux/vmalloc.h>
20 #include <linux/wait.h>
21 #include <asm/atomic.h>
22 #include <asm/unaligned.h>
24 #include <media/v4l2-common.h>
28 /* ------------------------------------------------------------------------
32 static int __uvc_query_ctrl(struct uvc_device
*dev
, __u8 query
, __u8 unit
,
33 __u8 intfnum
, __u8 cs
, void *data
, __u16 size
,
36 __u8 type
= USB_TYPE_CLASS
| USB_RECIP_INTERFACE
;
39 pipe
= (query
& 0x80) ? usb_rcvctrlpipe(dev
->udev
, 0)
40 : usb_sndctrlpipe(dev
->udev
, 0);
41 type
|= (query
& 0x80) ? USB_DIR_IN
: USB_DIR_OUT
;
43 return usb_control_msg(dev
->udev
, pipe
, query
, type
, cs
<< 8,
44 unit
<< 8 | intfnum
, data
, size
, timeout
);
47 int uvc_query_ctrl(struct uvc_device
*dev
, __u8 query
, __u8 unit
,
48 __u8 intfnum
, __u8 cs
, void *data
, __u16 size
)
52 ret
= __uvc_query_ctrl(dev
, query
, unit
, intfnum
, cs
, data
, size
,
53 UVC_CTRL_CONTROL_TIMEOUT
);
55 uvc_printk(KERN_ERR
, "Failed to query (%u) UVC control %u "
56 "(unit %u) : %d (exp. %u).\n", query
, cs
, unit
, ret
,
64 static void uvc_fixup_buffer_size(struct uvc_video_device
*video
,
65 struct uvc_streaming_control
*ctrl
)
67 struct uvc_format
*format
;
68 struct uvc_frame
*frame
;
70 if (ctrl
->bFormatIndex
<= 0 ||
71 ctrl
->bFormatIndex
> video
->streaming
->nformats
)
74 format
= &video
->streaming
->format
[ctrl
->bFormatIndex
- 1];
76 if (ctrl
->bFrameIndex
<= 0 ||
77 ctrl
->bFrameIndex
> format
->nframes
)
80 frame
= &format
->frame
[ctrl
->bFrameIndex
- 1];
82 if (!(format
->flags
& UVC_FMT_FLAG_COMPRESSED
) ||
83 (ctrl
->dwMaxVideoFrameSize
== 0 &&
84 video
->dev
->uvc_version
< 0x0110))
85 ctrl
->dwMaxVideoFrameSize
=
86 frame
->dwMaxVideoFrameBufferSize
;
89 static int uvc_get_video_ctrl(struct uvc_video_device
*video
,
90 struct uvc_streaming_control
*ctrl
, int probe
, __u8 query
)
96 size
= video
->dev
->uvc_version
>= 0x0110 ? 34 : 26;
97 data
= kmalloc(size
, GFP_KERNEL
);
101 ret
= __uvc_query_ctrl(video
->dev
, query
, 0, video
->streaming
->intfnum
,
102 probe
? VS_PROBE_CONTROL
: VS_COMMIT_CONTROL
, data
, size
,
103 UVC_CTRL_STREAMING_TIMEOUT
);
105 if ((query
== GET_MIN
|| query
== GET_MAX
) && ret
== 2) {
106 /* Some cameras, mostly based on Bison Electronics chipsets,
107 * answer a GET_MIN or GET_MAX request with the wCompQuality
110 uvc_warn_once(video
->dev
, UVC_WARN_MINMAX
, "UVC non "
111 "compliance - GET_MIN/MAX(PROBE) incorrectly "
112 "supported. Enabling workaround.\n");
113 memset(ctrl
, 0, sizeof ctrl
);
114 ctrl
->wCompQuality
= le16_to_cpup((__le16
*)data
);
117 } else if (query
== GET_DEF
&& probe
== 1 && ret
!= size
) {
118 /* Many cameras don't support the GET_DEF request on their
119 * video probe control. Warn once and return, the caller will
120 * fall back to GET_CUR.
122 uvc_warn_once(video
->dev
, UVC_WARN_PROBE_DEF
, "UVC non "
123 "compliance - GET_DEF(PROBE) not supported. "
124 "Enabling workaround.\n");
127 } else if (ret
!= size
) {
128 uvc_printk(KERN_ERR
, "Failed to query (%u) UVC %s control : "
129 "%d (exp. %u).\n", query
, probe
? "probe" : "commit",
135 ctrl
->bmHint
= le16_to_cpup((__le16
*)&data
[0]);
136 ctrl
->bFormatIndex
= data
[2];
137 ctrl
->bFrameIndex
= data
[3];
138 ctrl
->dwFrameInterval
= le32_to_cpup((__le32
*)&data
[4]);
139 ctrl
->wKeyFrameRate
= le16_to_cpup((__le16
*)&data
[8]);
140 ctrl
->wPFrameRate
= le16_to_cpup((__le16
*)&data
[10]);
141 ctrl
->wCompQuality
= le16_to_cpup((__le16
*)&data
[12]);
142 ctrl
->wCompWindowSize
= le16_to_cpup((__le16
*)&data
[14]);
143 ctrl
->wDelay
= le16_to_cpup((__le16
*)&data
[16]);
144 ctrl
->dwMaxVideoFrameSize
= get_unaligned_le32(&data
[18]);
145 ctrl
->dwMaxPayloadTransferSize
= get_unaligned_le32(&data
[22]);
148 ctrl
->dwClockFrequency
= get_unaligned_le32(&data
[26]);
149 ctrl
->bmFramingInfo
= data
[30];
150 ctrl
->bPreferedVersion
= data
[31];
151 ctrl
->bMinVersion
= data
[32];
152 ctrl
->bMaxVersion
= data
[33];
154 ctrl
->dwClockFrequency
= video
->dev
->clock_frequency
;
155 ctrl
->bmFramingInfo
= 0;
156 ctrl
->bPreferedVersion
= 0;
157 ctrl
->bMinVersion
= 0;
158 ctrl
->bMaxVersion
= 0;
161 /* Some broken devices return a null or wrong dwMaxVideoFrameSize.
162 * Try to get the value from the format and frame descriptors.
164 uvc_fixup_buffer_size(video
, ctrl
);
172 static int uvc_set_video_ctrl(struct uvc_video_device
*video
,
173 struct uvc_streaming_control
*ctrl
, int probe
)
179 size
= video
->dev
->uvc_version
>= 0x0110 ? 34 : 26;
180 data
= kzalloc(size
, GFP_KERNEL
);
184 *(__le16
*)&data
[0] = cpu_to_le16(ctrl
->bmHint
);
185 data
[2] = ctrl
->bFormatIndex
;
186 data
[3] = ctrl
->bFrameIndex
;
187 *(__le32
*)&data
[4] = cpu_to_le32(ctrl
->dwFrameInterval
);
188 *(__le16
*)&data
[8] = cpu_to_le16(ctrl
->wKeyFrameRate
);
189 *(__le16
*)&data
[10] = cpu_to_le16(ctrl
->wPFrameRate
);
190 *(__le16
*)&data
[12] = cpu_to_le16(ctrl
->wCompQuality
);
191 *(__le16
*)&data
[14] = cpu_to_le16(ctrl
->wCompWindowSize
);
192 *(__le16
*)&data
[16] = cpu_to_le16(ctrl
->wDelay
);
193 put_unaligned_le32(ctrl
->dwMaxVideoFrameSize
, &data
[18]);
194 put_unaligned_le32(ctrl
->dwMaxPayloadTransferSize
, &data
[22]);
197 put_unaligned_le32(ctrl
->dwClockFrequency
, &data
[26]);
198 data
[30] = ctrl
->bmFramingInfo
;
199 data
[31] = ctrl
->bPreferedVersion
;
200 data
[32] = ctrl
->bMinVersion
;
201 data
[33] = ctrl
->bMaxVersion
;
204 ret
= __uvc_query_ctrl(video
->dev
, SET_CUR
, 0,
205 video
->streaming
->intfnum
,
206 probe
? VS_PROBE_CONTROL
: VS_COMMIT_CONTROL
, data
, size
,
207 UVC_CTRL_STREAMING_TIMEOUT
);
209 uvc_printk(KERN_ERR
, "Failed to set UVC %s control : "
210 "%d (exp. %u).\n", probe
? "probe" : "commit",
219 int uvc_probe_video(struct uvc_video_device
*video
,
220 struct uvc_streaming_control
*probe
)
222 struct uvc_streaming_control probe_min
, probe_max
;
227 mutex_lock(&video
->streaming
->mutex
);
229 /* Perform probing. The device should adjust the requested values
230 * according to its capabilities. However, some devices, namely the
231 * first generation UVC Logitech webcams, don't implement the Video
232 * Probe control properly, and just return the needed bandwidth. For
233 * that reason, if the needed bandwidth exceeds the maximum available
234 * bandwidth, try to lower the quality.
236 if ((ret
= uvc_set_video_ctrl(video
, probe
, 1)) < 0)
239 /* Get the minimum and maximum values for compression settings. */
240 if (!(video
->dev
->quirks
& UVC_QUIRK_PROBE_MINMAX
)) {
241 ret
= uvc_get_video_ctrl(video
, &probe_min
, 1, GET_MIN
);
244 ret
= uvc_get_video_ctrl(video
, &probe_max
, 1, GET_MAX
);
248 probe
->wCompQuality
= probe_max
.wCompQuality
;
251 for (i
= 0; i
< 2; ++i
) {
252 if ((ret
= uvc_set_video_ctrl(video
, probe
, 1)) < 0 ||
253 (ret
= uvc_get_video_ctrl(video
, probe
, 1, GET_CUR
)) < 0)
256 if (video
->streaming
->intf
->num_altsetting
== 1)
259 bandwidth
= probe
->dwMaxPayloadTransferSize
;
260 if (bandwidth
<= video
->streaming
->maxpsize
)
263 if (video
->dev
->quirks
& UVC_QUIRK_PROBE_MINMAX
) {
268 /* TODO: negotiate compression parameters */
269 probe
->wKeyFrameRate
= probe_min
.wKeyFrameRate
;
270 probe
->wPFrameRate
= probe_min
.wPFrameRate
;
271 probe
->wCompQuality
= probe_max
.wCompQuality
;
272 probe
->wCompWindowSize
= probe_min
.wCompWindowSize
;
276 mutex_unlock(&video
->streaming
->mutex
);
280 int uvc_commit_video(struct uvc_video_device
*video
,
281 struct uvc_streaming_control
*probe
)
283 return uvc_set_video_ctrl(video
, probe
, 0);
286 /* ------------------------------------------------------------------------
290 /* Values for bmHeaderInfo (Video and Still Image Payload Headers, 2.4.3.3) */
291 #define UVC_STREAM_EOH (1 << 7)
292 #define UVC_STREAM_ERR (1 << 6)
293 #define UVC_STREAM_STI (1 << 5)
294 #define UVC_STREAM_RES (1 << 4)
295 #define UVC_STREAM_SCR (1 << 3)
296 #define UVC_STREAM_PTS (1 << 2)
297 #define UVC_STREAM_EOF (1 << 1)
298 #define UVC_STREAM_FID (1 << 0)
300 /* Video payload decoding is handled by uvc_video_decode_start(),
301 * uvc_video_decode_data() and uvc_video_decode_end().
303 * uvc_video_decode_start is called with URB data at the start of a bulk or
304 * isochronous payload. It processes header data and returns the header size
305 * in bytes if successful. If an error occurs, it returns a negative error
306 * code. The following error codes have special meanings.
308 * - EAGAIN informs the caller that the current video buffer should be marked
309 * as done, and that the function should be called again with the same data
310 * and a new video buffer. This is used when end of frame conditions can be
311 * reliably detected at the beginning of the next frame only.
313 * If an error other than -EAGAIN is returned, the caller will drop the current
314 * payload. No call to uvc_video_decode_data and uvc_video_decode_end will be
315 * made until the next payload. -ENODATA can be used to drop the current
316 * payload if no other error code is appropriate.
318 * uvc_video_decode_data is called for every URB with URB data. It copies the
319 * data to the video buffer.
321 * uvc_video_decode_end is called with header data at the end of a bulk or
322 * isochronous payload. It performs any additional header data processing and
323 * returns 0 or a negative error code if an error occured. As header data have
324 * already been processed by uvc_video_decode_start, this functions isn't
325 * required to perform sanity checks a second time.
327 * For isochronous transfers where a payload is always transfered in a single
328 * URB, the three functions will be called in a row.
330 * To let the decoder process header data and update its internal state even
331 * when no video buffer is available, uvc_video_decode_start must be prepared
332 * to be called with a NULL buf parameter. uvc_video_decode_data and
333 * uvc_video_decode_end will never be called with a NULL buffer.
335 static int uvc_video_decode_start(struct uvc_video_device
*video
,
336 struct uvc_buffer
*buf
, const __u8
*data
, int len
)
341 * - packet must be at least 2 bytes long
342 * - bHeaderLength value must be at least 2 bytes (see above)
343 * - bHeaderLength value can't be larger than the packet size.
345 if (len
< 2 || data
[0] < 2 || data
[0] > len
)
348 /* Skip payloads marked with the error bit ("error frames"). */
349 if (data
[1] & UVC_STREAM_ERR
) {
350 uvc_trace(UVC_TRACE_FRAME
, "Dropping payload (error bit "
355 fid
= data
[1] & UVC_STREAM_FID
;
357 /* Store the payload FID bit and return immediately when the buffer is
361 video
->last_fid
= fid
;
365 /* Synchronize to the input stream by waiting for the FID bit to be
366 * toggled when the the buffer state is not UVC_BUF_STATE_ACTIVE.
367 * video->last_fid is initialized to -1, so the first isochronous
368 * frame will always be in sync.
370 * If the device doesn't toggle the FID bit, invert video->last_fid
371 * when the EOF bit is set to force synchronisation on the next packet.
373 if (buf
->state
!= UVC_BUF_STATE_ACTIVE
) {
374 if (fid
== video
->last_fid
) {
375 uvc_trace(UVC_TRACE_FRAME
, "Dropping payload (out of "
377 if ((video
->dev
->quirks
& UVC_QUIRK_STREAM_NO_FID
) &&
378 (data
[1] & UVC_STREAM_EOF
))
379 video
->last_fid
^= UVC_STREAM_FID
;
383 /* TODO: Handle PTS and SCR. */
384 buf
->state
= UVC_BUF_STATE_ACTIVE
;
387 /* Mark the buffer as done if we're at the beginning of a new frame.
388 * End of frame detection is better implemented by checking the EOF
389 * bit (FID bit toggling is delayed by one frame compared to the EOF
390 * bit), but some devices don't set the bit at end of frame (and the
391 * last payload can be lost anyway). We thus must check if the FID has
394 * video->last_fid is initialized to -1, so the first isochronous
395 * frame will never trigger an end of frame detection.
397 * Empty buffers (bytesused == 0) don't trigger end of frame detection
398 * as it doesn't make sense to return an empty buffer. This also
399 * avoids detecting end of frame conditions at FID toggling if the
400 * previous payload had the EOF bit set.
402 if (fid
!= video
->last_fid
&& buf
->buf
.bytesused
!= 0) {
403 uvc_trace(UVC_TRACE_FRAME
, "Frame complete (FID bit "
405 buf
->state
= UVC_BUF_STATE_DONE
;
409 video
->last_fid
= fid
;
414 static void uvc_video_decode_data(struct uvc_video_device
*video
,
415 struct uvc_buffer
*buf
, const __u8
*data
, int len
)
417 struct uvc_video_queue
*queue
= &video
->queue
;
418 unsigned int maxlen
, nbytes
;
424 /* Copy the video data to the buffer. */
425 maxlen
= buf
->buf
.length
- buf
->buf
.bytesused
;
426 mem
= queue
->mem
+ buf
->buf
.m
.offset
+ buf
->buf
.bytesused
;
427 nbytes
= min((unsigned int)len
, maxlen
);
428 memcpy(mem
, data
, nbytes
);
429 buf
->buf
.bytesused
+= nbytes
;
431 /* Complete the current frame if the buffer size was exceeded. */
433 uvc_trace(UVC_TRACE_FRAME
, "Frame complete (overflow).\n");
434 buf
->state
= UVC_BUF_STATE_DONE
;
438 static void uvc_video_decode_end(struct uvc_video_device
*video
,
439 struct uvc_buffer
*buf
, const __u8
*data
, int len
)
441 /* Mark the buffer as done if the EOF marker is set. */
442 if (data
[1] & UVC_STREAM_EOF
&& buf
->buf
.bytesused
!= 0) {
443 uvc_trace(UVC_TRACE_FRAME
, "Frame complete (EOF found).\n");
445 uvc_trace(UVC_TRACE_FRAME
, "EOF in empty payload.\n");
446 buf
->state
= UVC_BUF_STATE_DONE
;
447 if (video
->dev
->quirks
& UVC_QUIRK_STREAM_NO_FID
)
448 video
->last_fid
^= UVC_STREAM_FID
;
452 /* Video payload encoding is handled by uvc_video_encode_header() and
453 * uvc_video_encode_data(). Only bulk transfers are currently supported.
455 * uvc_video_encode_header is called at the start of a payload. It adds header
456 * data to the transfer buffer and returns the header size. As the only known
457 * UVC output device transfers a whole frame in a single payload, the EOF bit
458 * is always set in the header.
460 * uvc_video_encode_data is called for every URB and copies the data from the
461 * video buffer to the transfer buffer.
463 static int uvc_video_encode_header(struct uvc_video_device
*video
,
464 struct uvc_buffer
*buf
, __u8
*data
, int len
)
466 data
[0] = 2; /* Header length */
467 data
[1] = UVC_STREAM_EOH
| UVC_STREAM_EOF
468 | (video
->last_fid
& UVC_STREAM_FID
);
472 static int uvc_video_encode_data(struct uvc_video_device
*video
,
473 struct uvc_buffer
*buf
, __u8
*data
, int len
)
475 struct uvc_video_queue
*queue
= &video
->queue
;
479 /* Copy video data to the URB buffer. */
480 mem
= queue
->mem
+ buf
->buf
.m
.offset
+ queue
->buf_used
;
481 nbytes
= min((unsigned int)len
, buf
->buf
.bytesused
- queue
->buf_used
);
482 nbytes
= min(video
->bulk
.max_payload_size
- video
->bulk
.payload_size
,
484 memcpy(data
, mem
, nbytes
);
486 queue
->buf_used
+= nbytes
;
491 /* ------------------------------------------------------------------------
496 * Completion handler for video URBs.
498 static void uvc_video_decode_isoc(struct urb
*urb
,
499 struct uvc_video_device
*video
, struct uvc_buffer
*buf
)
504 for (i
= 0; i
< urb
->number_of_packets
; ++i
) {
505 if (urb
->iso_frame_desc
[i
].status
< 0) {
506 uvc_trace(UVC_TRACE_FRAME
, "USB isochronous frame "
507 "lost (%d).\n", urb
->iso_frame_desc
[i
].status
);
511 /* Decode the payload header. */
512 mem
= urb
->transfer_buffer
+ urb
->iso_frame_desc
[i
].offset
;
514 ret
= uvc_video_decode_start(video
, buf
, mem
,
515 urb
->iso_frame_desc
[i
].actual_length
);
517 buf
= uvc_queue_next_buffer(&video
->queue
, buf
);
518 } while (ret
== -EAGAIN
);
523 /* Decode the payload data. */
524 uvc_video_decode_data(video
, buf
, mem
+ ret
,
525 urb
->iso_frame_desc
[i
].actual_length
- ret
);
527 /* Process the header again. */
528 uvc_video_decode_end(video
, buf
, mem
,
529 urb
->iso_frame_desc
[i
].actual_length
);
531 if (buf
->state
== UVC_BUF_STATE_DONE
||
532 buf
->state
== UVC_BUF_STATE_ERROR
)
533 buf
= uvc_queue_next_buffer(&video
->queue
, buf
);
537 static void uvc_video_decode_bulk(struct urb
*urb
,
538 struct uvc_video_device
*video
, struct uvc_buffer
*buf
)
543 mem
= urb
->transfer_buffer
;
544 len
= urb
->actual_length
;
545 video
->bulk
.payload_size
+= len
;
547 /* If the URB is the first of its payload, decode and save the
550 if (video
->bulk
.header_size
== 0 && !video
->bulk
.skip_payload
) {
552 ret
= uvc_video_decode_start(video
, buf
, mem
, len
);
554 buf
= uvc_queue_next_buffer(&video
->queue
, buf
);
555 } while (ret
== -EAGAIN
);
557 /* If an error occured skip the rest of the payload. */
558 if (ret
< 0 || buf
== NULL
) {
559 video
->bulk
.skip_payload
= 1;
561 memcpy(video
->bulk
.header
, mem
, ret
);
562 video
->bulk
.header_size
= ret
;
569 /* The buffer queue might have been cancelled while a bulk transfer
570 * was in progress, so we can reach here with buf equal to NULL. Make
571 * sure buf is never dereferenced if NULL.
574 /* Process video data. */
575 if (!video
->bulk
.skip_payload
&& buf
!= NULL
)
576 uvc_video_decode_data(video
, buf
, mem
, len
);
578 /* Detect the payload end by a URB smaller than the maximum size (or
579 * a payload size equal to the maximum) and process the header again.
581 if (urb
->actual_length
< urb
->transfer_buffer_length
||
582 video
->bulk
.payload_size
>= video
->bulk
.max_payload_size
) {
583 if (!video
->bulk
.skip_payload
&& buf
!= NULL
) {
584 uvc_video_decode_end(video
, buf
, video
->bulk
.header
,
585 video
->bulk
.payload_size
);
586 if (buf
->state
== UVC_BUF_STATE_DONE
||
587 buf
->state
== UVC_BUF_STATE_ERROR
)
588 buf
= uvc_queue_next_buffer(&video
->queue
, buf
);
591 video
->bulk
.header_size
= 0;
592 video
->bulk
.skip_payload
= 0;
593 video
->bulk
.payload_size
= 0;
597 static void uvc_video_encode_bulk(struct urb
*urb
,
598 struct uvc_video_device
*video
, struct uvc_buffer
*buf
)
600 u8
*mem
= urb
->transfer_buffer
;
601 int len
= video
->urb_size
, ret
;
604 urb
->transfer_buffer_length
= 0;
608 /* If the URB is the first of its payload, add the header. */
609 if (video
->bulk
.header_size
== 0) {
610 ret
= uvc_video_encode_header(video
, buf
, mem
, len
);
611 video
->bulk
.header_size
= ret
;
612 video
->bulk
.payload_size
+= ret
;
617 /* Process video data. */
618 ret
= uvc_video_encode_data(video
, buf
, mem
, len
);
620 video
->bulk
.payload_size
+= ret
;
623 if (buf
->buf
.bytesused
== video
->queue
.buf_used
||
624 video
->bulk
.payload_size
== video
->bulk
.max_payload_size
) {
625 if (buf
->buf
.bytesused
== video
->queue
.buf_used
) {
626 video
->queue
.buf_used
= 0;
627 buf
->state
= UVC_BUF_STATE_DONE
;
628 uvc_queue_next_buffer(&video
->queue
, buf
);
629 video
->last_fid
^= UVC_STREAM_FID
;
632 video
->bulk
.header_size
= 0;
633 video
->bulk
.payload_size
= 0;
636 urb
->transfer_buffer_length
= video
->urb_size
- len
;
639 static void uvc_video_complete(struct urb
*urb
)
641 struct uvc_video_device
*video
= urb
->context
;
642 struct uvc_video_queue
*queue
= &video
->queue
;
643 struct uvc_buffer
*buf
= NULL
;
647 switch (urb
->status
) {
652 uvc_printk(KERN_WARNING
, "Non-zero status (%d) in video "
653 "completion handler.\n", urb
->status
);
655 case -ENOENT
: /* usb_kill_urb() called. */
659 case -ECONNRESET
: /* usb_unlink_urb() called. */
660 case -ESHUTDOWN
: /* The endpoint is being disabled. */
661 uvc_queue_cancel(queue
, urb
->status
== -ESHUTDOWN
);
665 spin_lock_irqsave(&queue
->irqlock
, flags
);
666 if (!list_empty(&queue
->irqqueue
))
667 buf
= list_first_entry(&queue
->irqqueue
, struct uvc_buffer
,
669 spin_unlock_irqrestore(&queue
->irqlock
, flags
);
671 video
->decode(urb
, video
, buf
);
673 if ((ret
= usb_submit_urb(urb
, GFP_ATOMIC
)) < 0) {
674 uvc_printk(KERN_ERR
, "Failed to resubmit video URB (%d).\n",
680 * Free transfer buffers.
682 static void uvc_free_urb_buffers(struct uvc_video_device
*video
)
686 for (i
= 0; i
< UVC_URBS
; ++i
) {
687 if (video
->urb_buffer
[i
]) {
688 usb_buffer_free(video
->dev
->udev
, video
->urb_size
,
689 video
->urb_buffer
[i
], video
->urb_dma
[i
]);
690 video
->urb_buffer
[i
] = NULL
;
698 * Allocate transfer buffers. This function can be called with buffers
699 * already allocated when resuming from suspend, in which case it will
700 * return without touching the buffers.
702 * Limit the buffer size to UVC_MAX_PACKETS bulk/isochronous packets. If the
703 * system is too low on memory try successively smaller numbers of packets
704 * until allocation succeeds.
706 * Return the number of allocated packets on success or 0 when out of memory.
708 static int uvc_alloc_urb_buffers(struct uvc_video_device
*video
,
709 unsigned int size
, unsigned int psize
, gfp_t gfp_flags
)
711 unsigned int npackets
;
714 /* Buffers are already allocated, bail out. */
718 /* Compute the number of packets. Bulk endpoints might transfer UVC
719 * payloads accross multiple URBs.
721 npackets
= DIV_ROUND_UP(size
, psize
);
722 if (npackets
> UVC_MAX_PACKETS
)
723 npackets
= UVC_MAX_PACKETS
;
725 /* Retry allocations until one succeed. */
726 for (; npackets
> 1; npackets
/= 2) {
727 for (i
= 0; i
< UVC_URBS
; ++i
) {
728 video
->urb_buffer
[i
] = usb_buffer_alloc(
729 video
->dev
->udev
, psize
* npackets
,
730 gfp_flags
| __GFP_NOWARN
, &video
->urb_dma
[i
]);
731 if (!video
->urb_buffer
[i
]) {
732 uvc_free_urb_buffers(video
);
738 video
->urb_size
= psize
* npackets
;
747 * Uninitialize isochronous/bulk URBs and free transfer buffers.
749 static void uvc_uninit_video(struct uvc_video_device
*video
, int free_buffers
)
754 for (i
= 0; i
< UVC_URBS
; ++i
) {
755 if ((urb
= video
->urb
[i
]) == NULL
)
760 video
->urb
[i
] = NULL
;
764 uvc_free_urb_buffers(video
);
768 * Initialize isochronous URBs and allocate transfer buffers. The packet size
769 * is given by the endpoint.
771 static int uvc_init_video_isoc(struct uvc_video_device
*video
,
772 struct usb_host_endpoint
*ep
, gfp_t gfp_flags
)
775 unsigned int npackets
, i
, j
;
779 psize
= le16_to_cpu(ep
->desc
.wMaxPacketSize
);
780 psize
= (psize
& 0x07ff) * (1 + ((psize
>> 11) & 3));
781 size
= video
->streaming
->ctrl
.dwMaxVideoFrameSize
;
783 npackets
= uvc_alloc_urb_buffers(video
, size
, psize
, gfp_flags
);
787 size
= npackets
* psize
;
789 for (i
= 0; i
< UVC_URBS
; ++i
) {
790 urb
= usb_alloc_urb(npackets
, gfp_flags
);
792 uvc_uninit_video(video
, 1);
796 urb
->dev
= video
->dev
->udev
;
797 urb
->context
= video
;
798 urb
->pipe
= usb_rcvisocpipe(video
->dev
->udev
,
799 ep
->desc
.bEndpointAddress
);
800 urb
->transfer_flags
= URB_ISO_ASAP
| URB_NO_TRANSFER_DMA_MAP
;
801 urb
->interval
= ep
->desc
.bInterval
;
802 urb
->transfer_buffer
= video
->urb_buffer
[i
];
803 urb
->transfer_dma
= video
->urb_dma
[i
];
804 urb
->complete
= uvc_video_complete
;
805 urb
->number_of_packets
= npackets
;
806 urb
->transfer_buffer_length
= size
;
808 for (j
= 0; j
< npackets
; ++j
) {
809 urb
->iso_frame_desc
[j
].offset
= j
* psize
;
810 urb
->iso_frame_desc
[j
].length
= psize
;
820 * Initialize bulk URBs and allocate transfer buffers. The packet size is
821 * given by the endpoint.
823 static int uvc_init_video_bulk(struct uvc_video_device
*video
,
824 struct usb_host_endpoint
*ep
, gfp_t gfp_flags
)
827 unsigned int npackets
, pipe
, i
;
831 psize
= le16_to_cpu(ep
->desc
.wMaxPacketSize
) & 0x07ff;
832 size
= video
->streaming
->ctrl
.dwMaxPayloadTransferSize
;
833 video
->bulk
.max_payload_size
= size
;
835 npackets
= uvc_alloc_urb_buffers(video
, size
, psize
, gfp_flags
);
839 size
= npackets
* psize
;
841 if (usb_endpoint_dir_in(&ep
->desc
))
842 pipe
= usb_rcvbulkpipe(video
->dev
->udev
,
843 ep
->desc
.bEndpointAddress
);
845 pipe
= usb_sndbulkpipe(video
->dev
->udev
,
846 ep
->desc
.bEndpointAddress
);
848 if (video
->streaming
->type
== V4L2_BUF_TYPE_VIDEO_OUTPUT
)
851 for (i
= 0; i
< UVC_URBS
; ++i
) {
852 urb
= usb_alloc_urb(0, gfp_flags
);
854 uvc_uninit_video(video
, 1);
858 usb_fill_bulk_urb(urb
, video
->dev
->udev
, pipe
,
859 video
->urb_buffer
[i
], size
, uvc_video_complete
,
861 urb
->transfer_flags
= URB_NO_TRANSFER_DMA_MAP
;
862 urb
->transfer_dma
= video
->urb_dma
[i
];
871 * Initialize isochronous/bulk URBs and allocate transfer buffers.
873 static int uvc_init_video(struct uvc_video_device
*video
, gfp_t gfp_flags
)
875 struct usb_interface
*intf
= video
->streaming
->intf
;
876 struct usb_host_interface
*alts
;
877 struct usb_host_endpoint
*ep
= NULL
;
878 int intfnum
= video
->streaming
->intfnum
;
879 unsigned int bandwidth
, psize
, i
;
882 video
->last_fid
= -1;
883 video
->bulk
.header_size
= 0;
884 video
->bulk
.skip_payload
= 0;
885 video
->bulk
.payload_size
= 0;
887 if (intf
->num_altsetting
> 1) {
888 /* Isochronous endpoint, select the alternate setting. */
889 bandwidth
= video
->streaming
->ctrl
.dwMaxPayloadTransferSize
;
891 if (bandwidth
== 0) {
892 uvc_printk(KERN_WARNING
, "device %s requested null "
893 "bandwidth, defaulting to lowest.\n",
898 for (i
= 0; i
< intf
->num_altsetting
; ++i
) {
899 alts
= &intf
->altsetting
[i
];
900 ep
= uvc_find_endpoint(alts
,
901 video
->streaming
->header
.bEndpointAddress
);
905 /* Check if the bandwidth is high enough. */
906 psize
= le16_to_cpu(ep
->desc
.wMaxPacketSize
);
907 psize
= (psize
& 0x07ff) * (1 + ((psize
>> 11) & 3));
908 if (psize
>= bandwidth
)
912 if (i
>= intf
->num_altsetting
)
915 if ((ret
= usb_set_interface(video
->dev
->udev
, intfnum
, i
)) < 0)
918 ret
= uvc_init_video_isoc(video
, ep
, gfp_flags
);
920 /* Bulk endpoint, proceed to URB initialization. */
921 ep
= uvc_find_endpoint(&intf
->altsetting
[0],
922 video
->streaming
->header
.bEndpointAddress
);
926 ret
= uvc_init_video_bulk(video
, ep
, gfp_flags
);
932 /* Submit the URBs. */
933 for (i
= 0; i
< UVC_URBS
; ++i
) {
934 if ((ret
= usb_submit_urb(video
->urb
[i
], gfp_flags
)) < 0) {
935 uvc_printk(KERN_ERR
, "Failed to submit URB %u "
937 uvc_uninit_video(video
, 1);
945 /* --------------------------------------------------------------------------
950 * Stop streaming without disabling the video queue.
952 * To let userspace applications resume without trouble, we must not touch the
953 * video buffers in any way. We mark the device as frozen to make sure the URB
954 * completion handler won't try to cancel the queue when we kill the URBs.
956 int uvc_video_suspend(struct uvc_video_device
*video
)
958 if (!uvc_queue_streaming(&video
->queue
))
962 uvc_uninit_video(video
, 0);
963 usb_set_interface(video
->dev
->udev
, video
->streaming
->intfnum
, 0);
968 * Reconfigure the video interface and restart streaming if it was enabled
971 * If an error occurs, disable the video queue. This will wake all pending
972 * buffers, making sure userspace applications are notified of the problem
973 * instead of waiting forever.
975 int uvc_video_resume(struct uvc_video_device
*video
)
981 if ((ret
= uvc_commit_video(video
, &video
->streaming
->ctrl
)) < 0) {
982 uvc_queue_enable(&video
->queue
, 0);
986 if (!uvc_queue_streaming(&video
->queue
))
989 if ((ret
= uvc_init_video(video
, GFP_NOIO
)) < 0)
990 uvc_queue_enable(&video
->queue
, 0);
995 /* ------------------------------------------------------------------------
1000 * Initialize the UVC video device by switching to alternate setting 0 and
1001 * retrieve the default format.
1003 * Some cameras (namely the Fuji Finepix) set the format and frame
1004 * indexes to zero. The UVC standard doesn't clearly make this a spec
1005 * violation, so try to silently fix the values if possible.
1007 * This function is called before registering the device with V4L.
1009 int uvc_video_init(struct uvc_video_device
*video
)
1011 struct uvc_streaming_control
*probe
= &video
->streaming
->ctrl
;
1012 struct uvc_format
*format
= NULL
;
1013 struct uvc_frame
*frame
= NULL
;
1017 if (video
->streaming
->nformats
== 0) {
1018 uvc_printk(KERN_INFO
, "No supported video formats found.\n");
1022 /* Alternate setting 0 should be the default, yet the XBox Live Vision
1023 * Cam (and possibly other devices) crash or otherwise misbehave if
1024 * they don't receive a SET_INTERFACE request before any other video
1027 usb_set_interface(video
->dev
->udev
, video
->streaming
->intfnum
, 0);
1029 /* Set the streaming probe control with default streaming parameters
1030 * retrieved from the device. Webcams that don't suport GET_DEF
1031 * requests on the probe control will just keep their current streaming
1034 if (uvc_get_video_ctrl(video
, probe
, 1, GET_DEF
) == 0)
1035 uvc_set_video_ctrl(video
, probe
, 1);
1037 /* Initialize the streaming parameters with the probe control current
1038 * value. This makes sure SET_CUR requests on the streaming commit
1039 * control will always use values retrieved from a successful GET_CUR
1040 * request on the probe control, as required by the UVC specification.
1042 if ((ret
= uvc_get_video_ctrl(video
, probe
, 1, GET_CUR
)) < 0)
1045 /* Check if the default format descriptor exists. Use the first
1046 * available format otherwise.
1048 for (i
= video
->streaming
->nformats
; i
> 0; --i
) {
1049 format
= &video
->streaming
->format
[i
-1];
1050 if (format
->index
== probe
->bFormatIndex
)
1054 if (format
->nframes
== 0) {
1055 uvc_printk(KERN_INFO
, "No frame descriptor found for the "
1056 "default format.\n");
1060 /* Zero bFrameIndex might be correct. Stream-based formats (including
1061 * MPEG-2 TS and DV) do not support frames but have a dummy frame
1062 * descriptor with bFrameIndex set to zero. If the default frame
1063 * descriptor is not found, use the first avalable frame.
1065 for (i
= format
->nframes
; i
> 0; --i
) {
1066 frame
= &format
->frame
[i
-1];
1067 if (frame
->bFrameIndex
== probe
->bFrameIndex
)
1071 probe
->bFormatIndex
= format
->index
;
1072 probe
->bFrameIndex
= frame
->bFrameIndex
;
1074 video
->streaming
->cur_format
= format
;
1075 video
->streaming
->cur_frame
= frame
;
1076 atomic_set(&video
->active
, 0);
1078 /* Select the video decoding function */
1079 if (video
->streaming
->type
== V4L2_BUF_TYPE_VIDEO_CAPTURE
) {
1080 if (video
->dev
->quirks
& UVC_QUIRK_BUILTIN_ISIGHT
)
1081 video
->decode
= uvc_video_decode_isight
;
1082 else if (video
->streaming
->intf
->num_altsetting
> 1)
1083 video
->decode
= uvc_video_decode_isoc
;
1085 video
->decode
= uvc_video_decode_bulk
;
1087 if (video
->streaming
->intf
->num_altsetting
== 1)
1088 video
->decode
= uvc_video_encode_bulk
;
1090 uvc_printk(KERN_INFO
, "Isochronous endpoints are not "
1091 "supported for video output devices.\n");
1100 * Enable or disable the video stream.
1102 int uvc_video_enable(struct uvc_video_device
*video
, int enable
)
1107 uvc_uninit_video(video
, 1);
1108 usb_set_interface(video
->dev
->udev
,
1109 video
->streaming
->intfnum
, 0);
1110 uvc_queue_enable(&video
->queue
, 0);
1114 if ((video
->streaming
->cur_format
->flags
& UVC_FMT_FLAG_COMPRESSED
) ||
1116 video
->queue
.flags
&= ~UVC_QUEUE_DROP_INCOMPLETE
;
1118 video
->queue
.flags
|= UVC_QUEUE_DROP_INCOMPLETE
;
1120 if ((ret
= uvc_queue_enable(&video
->queue
, 1)) < 0)
1123 /* Commit the streaming parameters. */
1124 if ((ret
= uvc_commit_video(video
, &video
->streaming
->ctrl
)) < 0)
1127 return uvc_init_video(video
, GFP_KERNEL
);