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_video_ctrl(struct uvc_video_device *video,
65 struct uvc_streaming_control *ctrl)
67 struct uvc_format *format;
68 struct uvc_frame *frame = NULL;
71 if (ctrl->bFormatIndex <= 0 ||
72 ctrl->bFormatIndex > video->streaming->nformats)
75 format = &video->streaming->format[ctrl->bFormatIndex - 1];
77 for (i = 0; i < format->nframes; ++i) {
78 if (format->frame[i].bFrameIndex == ctrl->bFrameIndex) {
79 frame = &format->frame[i];
87 if (!(format->flags & UVC_FMT_FLAG_COMPRESSED) ||
88 (ctrl->dwMaxVideoFrameSize == 0 &&
89 video->dev->uvc_version < 0x0110))
90 ctrl->dwMaxVideoFrameSize =
91 frame->dwMaxVideoFrameBufferSize;
93 if (video->dev->quirks & UVC_QUIRK_FIX_BANDWIDTH &&
94 video->streaming->intf->num_altsetting > 1) {
98 interval = (ctrl->dwFrameInterval > 100000)
99 ? ctrl->dwFrameInterval
100 : frame->dwFrameInterval[0];
102 /* Compute a bandwidth estimation by multiplying the frame
103 * size by the number of video frames per second, divide the
104 * result by the number of USB frames (or micro-frames for
105 * high-speed devices) per second and add the UVC header size
106 * (assumed to be 12 bytes long).
108 bandwidth = frame->wWidth * frame->wHeight / 8 * format->bpp;
109 bandwidth *= 10000000 / interval + 1;
111 if (video->dev->udev->speed == USB_SPEED_HIGH)
115 ctrl->dwMaxPayloadTransferSize = bandwidth;
119 static int uvc_get_video_ctrl(struct uvc_video_device *video,
120 struct uvc_streaming_control *ctrl, int probe, __u8 query)
126 size = video->dev->uvc_version >= 0x0110 ? 34 : 26;
127 data = kmalloc(size, GFP_KERNEL);
131 if ((video->dev->quirks & UVC_QUIRK_PROBE_DEF) && query == UVC_GET_DEF)
134 ret = __uvc_query_ctrl(video->dev, query, 0, video->streaming->intfnum,
135 probe ? UVC_VS_PROBE_CONTROL : UVC_VS_COMMIT_CONTROL, data,
136 size, UVC_CTRL_STREAMING_TIMEOUT);
138 if ((query == UVC_GET_MIN || query == UVC_GET_MAX) && ret == 2) {
139 /* Some cameras, mostly based on Bison Electronics chipsets,
140 * answer a GET_MIN or GET_MAX request with the wCompQuality
143 uvc_warn_once(video->dev, UVC_WARN_MINMAX, "UVC non "
144 "compliance - GET_MIN/MAX(PROBE) incorrectly "
145 "supported. Enabling workaround.\n");
146 memset(ctrl, 0, sizeof ctrl);
147 ctrl->wCompQuality = le16_to_cpup((__le16 *)data);
150 } else if (query == UVC_GET_DEF && probe == 1 && ret != size) {
151 /* Many cameras don't support the GET_DEF request on their
152 * video probe control. Warn once and return, the caller will
153 * fall back to GET_CUR.
155 uvc_warn_once(video->dev, UVC_WARN_PROBE_DEF, "UVC non "
156 "compliance - GET_DEF(PROBE) not supported. "
157 "Enabling workaround.\n");
160 } else if (ret != size) {
161 uvc_printk(KERN_ERR, "Failed to query (%u) UVC %s control : "
162 "%d (exp. %u).\n", query, probe ? "probe" : "commit",
168 ctrl->bmHint = le16_to_cpup((__le16 *)&data[0]);
169 ctrl->bFormatIndex = data[2];
170 ctrl->bFrameIndex = data[3];
171 ctrl->dwFrameInterval = le32_to_cpup((__le32 *)&data[4]);
172 ctrl->wKeyFrameRate = le16_to_cpup((__le16 *)&data[8]);
173 ctrl->wPFrameRate = le16_to_cpup((__le16 *)&data[10]);
174 ctrl->wCompQuality = le16_to_cpup((__le16 *)&data[12]);
175 ctrl->wCompWindowSize = le16_to_cpup((__le16 *)&data[14]);
176 ctrl->wDelay = le16_to_cpup((__le16 *)&data[16]);
177 ctrl->dwMaxVideoFrameSize = get_unaligned_le32(&data[18]);
178 ctrl->dwMaxPayloadTransferSize = get_unaligned_le32(&data[22]);
181 ctrl->dwClockFrequency = get_unaligned_le32(&data[26]);
182 ctrl->bmFramingInfo = data[30];
183 ctrl->bPreferedVersion = data[31];
184 ctrl->bMinVersion = data[32];
185 ctrl->bMaxVersion = data[33];
187 ctrl->dwClockFrequency = video->dev->clock_frequency;
188 ctrl->bmFramingInfo = 0;
189 ctrl->bPreferedVersion = 0;
190 ctrl->bMinVersion = 0;
191 ctrl->bMaxVersion = 0;
194 /* Some broken devices return null or wrong dwMaxVideoFrameSize and
195 * dwMaxPayloadTransferSize fields. Try to get the value from the
196 * format and frame descriptors.
198 uvc_fixup_video_ctrl(video, ctrl);
206 static int uvc_set_video_ctrl(struct uvc_video_device *video,
207 struct uvc_streaming_control *ctrl, int probe)
213 size = video->dev->uvc_version >= 0x0110 ? 34 : 26;
214 data = kzalloc(size, GFP_KERNEL);
218 *(__le16 *)&data[0] = cpu_to_le16(ctrl->bmHint);
219 data[2] = ctrl->bFormatIndex;
220 data[3] = ctrl->bFrameIndex;
221 *(__le32 *)&data[4] = cpu_to_le32(ctrl->dwFrameInterval);
222 *(__le16 *)&data[8] = cpu_to_le16(ctrl->wKeyFrameRate);
223 *(__le16 *)&data[10] = cpu_to_le16(ctrl->wPFrameRate);
224 *(__le16 *)&data[12] = cpu_to_le16(ctrl->wCompQuality);
225 *(__le16 *)&data[14] = cpu_to_le16(ctrl->wCompWindowSize);
226 *(__le16 *)&data[16] = cpu_to_le16(ctrl->wDelay);
227 put_unaligned_le32(ctrl->dwMaxVideoFrameSize, &data[18]);
228 put_unaligned_le32(ctrl->dwMaxPayloadTransferSize, &data[22]);
231 put_unaligned_le32(ctrl->dwClockFrequency, &data[26]);
232 data[30] = ctrl->bmFramingInfo;
233 data[31] = ctrl->bPreferedVersion;
234 data[32] = ctrl->bMinVersion;
235 data[33] = ctrl->bMaxVersion;
238 ret = __uvc_query_ctrl(video->dev, UVC_SET_CUR, 0,
239 video->streaming->intfnum,
240 probe ? UVC_VS_PROBE_CONTROL : UVC_VS_COMMIT_CONTROL, data,
241 size, UVC_CTRL_STREAMING_TIMEOUT);
243 uvc_printk(KERN_ERR, "Failed to set UVC %s control : "
244 "%d (exp. %u).\n", probe ? "probe" : "commit",
253 int uvc_probe_video(struct uvc_video_device *video,
254 struct uvc_streaming_control *probe)
256 struct uvc_streaming_control probe_min, probe_max;
261 mutex_lock(&video->streaming->mutex);
263 /* Perform probing. The device should adjust the requested values
264 * according to its capabilities. However, some devices, namely the
265 * first generation UVC Logitech webcams, don't implement the Video
266 * Probe control properly, and just return the needed bandwidth. For
267 * that reason, if the needed bandwidth exceeds the maximum available
268 * bandwidth, try to lower the quality.
270 if ((ret = uvc_set_video_ctrl(video, probe, 1)) < 0)
273 /* Get the minimum and maximum values for compression settings. */
274 if (!(video->dev->quirks & UVC_QUIRK_PROBE_MINMAX)) {
275 ret = uvc_get_video_ctrl(video, &probe_min, 1, UVC_GET_MIN);
278 ret = uvc_get_video_ctrl(video, &probe_max, 1, UVC_GET_MAX);
282 probe->wCompQuality = probe_max.wCompQuality;
285 for (i = 0; i < 2; ++i) {
286 ret = uvc_set_video_ctrl(video, probe, 1);
289 ret = uvc_get_video_ctrl(video, probe, 1, UVC_GET_CUR);
293 if (video->streaming->intf->num_altsetting == 1)
296 bandwidth = probe->dwMaxPayloadTransferSize;
297 if (bandwidth <= video->streaming->maxpsize)
300 if (video->dev->quirks & UVC_QUIRK_PROBE_MINMAX) {
305 /* TODO: negotiate compression parameters */
306 probe->wKeyFrameRate = probe_min.wKeyFrameRate;
307 probe->wPFrameRate = probe_min.wPFrameRate;
308 probe->wCompQuality = probe_max.wCompQuality;
309 probe->wCompWindowSize = probe_min.wCompWindowSize;
313 mutex_unlock(&video->streaming->mutex);
317 int uvc_commit_video(struct uvc_video_device *video,
318 struct uvc_streaming_control *probe)
320 return uvc_set_video_ctrl(video, probe, 0);
323 /* ------------------------------------------------------------------------
327 /* Values for bmHeaderInfo (Video and Still Image Payload Headers, 2.4.3.3) */
328 #define UVC_STREAM_EOH (1 << 7)
329 #define UVC_STREAM_ERR (1 << 6)
330 #define UVC_STREAM_STI (1 << 5)
331 #define UVC_STREAM_RES (1 << 4)
332 #define UVC_STREAM_SCR (1 << 3)
333 #define UVC_STREAM_PTS (1 << 2)
334 #define UVC_STREAM_EOF (1 << 1)
335 #define UVC_STREAM_FID (1 << 0)
337 /* Video payload decoding is handled by uvc_video_decode_start(),
338 * uvc_video_decode_data() and uvc_video_decode_end().
340 * uvc_video_decode_start is called with URB data at the start of a bulk or
341 * isochronous payload. It processes header data and returns the header size
342 * in bytes if successful. If an error occurs, it returns a negative error
343 * code. The following error codes have special meanings.
345 * - EAGAIN informs the caller that the current video buffer should be marked
346 * as done, and that the function should be called again with the same data
347 * and a new video buffer. This is used when end of frame conditions can be
348 * reliably detected at the beginning of the next frame only.
350 * If an error other than -EAGAIN is returned, the caller will drop the current
351 * payload. No call to uvc_video_decode_data and uvc_video_decode_end will be
352 * made until the next payload. -ENODATA can be used to drop the current
353 * payload if no other error code is appropriate.
355 * uvc_video_decode_data is called for every URB with URB data. It copies the
356 * data to the video buffer.
358 * uvc_video_decode_end is called with header data at the end of a bulk or
359 * isochronous payload. It performs any additional header data processing and
360 * returns 0 or a negative error code if an error occured. As header data have
361 * already been processed by uvc_video_decode_start, this functions isn't
362 * required to perform sanity checks a second time.
364 * For isochronous transfers where a payload is always transfered in a single
365 * URB, the three functions will be called in a row.
367 * To let the decoder process header data and update its internal state even
368 * when no video buffer is available, uvc_video_decode_start must be prepared
369 * to be called with a NULL buf parameter. uvc_video_decode_data and
370 * uvc_video_decode_end will never be called with a NULL buffer.
372 static int uvc_video_decode_start(struct uvc_video_device *video,
373 struct uvc_buffer *buf, const __u8 *data, int len)
378 * - packet must be at least 2 bytes long
379 * - bHeaderLength value must be at least 2 bytes (see above)
380 * - bHeaderLength value can't be larger than the packet size.
382 if (len < 2 || data[0] < 2 || data[0] > len)
385 /* Skip payloads marked with the error bit ("error frames"). */
386 if (data[1] & UVC_STREAM_ERR) {
387 uvc_trace(UVC_TRACE_FRAME, "Dropping payload (error bit "
392 fid = data[1] & UVC_STREAM_FID;
394 /* Store the payload FID bit and return immediately when the buffer is
398 video->last_fid = fid;
402 /* Synchronize to the input stream by waiting for the FID bit to be
403 * toggled when the the buffer state is not UVC_BUF_STATE_ACTIVE.
404 * video->last_fid is initialized to -1, so the first isochronous
405 * frame will always be in sync.
407 * If the device doesn't toggle the FID bit, invert video->last_fid
408 * when the EOF bit is set to force synchronisation on the next packet.
410 if (buf->state != UVC_BUF_STATE_ACTIVE) {
411 if (fid == video->last_fid) {
412 uvc_trace(UVC_TRACE_FRAME, "Dropping payload (out of "
414 if ((video->dev->quirks & UVC_QUIRK_STREAM_NO_FID) &&
415 (data[1] & UVC_STREAM_EOF))
416 video->last_fid ^= UVC_STREAM_FID;
420 /* TODO: Handle PTS and SCR. */
421 buf->state = UVC_BUF_STATE_ACTIVE;
424 /* Mark the buffer as done if we're at the beginning of a new frame.
425 * End of frame detection is better implemented by checking the EOF
426 * bit (FID bit toggling is delayed by one frame compared to the EOF
427 * bit), but some devices don't set the bit at end of frame (and the
428 * last payload can be lost anyway). We thus must check if the FID has
431 * video->last_fid is initialized to -1, so the first isochronous
432 * frame will never trigger an end of frame detection.
434 * Empty buffers (bytesused == 0) don't trigger end of frame detection
435 * as it doesn't make sense to return an empty buffer. This also
436 * avoids detecting end of frame conditions at FID toggling if the
437 * previous payload had the EOF bit set.
439 if (fid != video->last_fid && buf->buf.bytesused != 0) {
440 uvc_trace(UVC_TRACE_FRAME, "Frame complete (FID bit "
442 buf->state = UVC_BUF_STATE_DONE;
446 video->last_fid = fid;
451 static void uvc_video_decode_data(struct uvc_video_device *video,
452 struct uvc_buffer *buf, const __u8 *data, int len)
454 struct uvc_video_queue *queue = &video->queue;
455 unsigned int maxlen, nbytes;
461 /* Copy the video data to the buffer. */
462 maxlen = buf->buf.length - buf->buf.bytesused;
463 mem = queue->mem + buf->buf.m.offset + buf->buf.bytesused;
464 nbytes = min((unsigned int)len, maxlen);
465 memcpy(mem, data, nbytes);
466 buf->buf.bytesused += nbytes;
468 /* Complete the current frame if the buffer size was exceeded. */
470 uvc_trace(UVC_TRACE_FRAME, "Frame complete (overflow).\n");
471 buf->state = UVC_BUF_STATE_DONE;
475 static void uvc_video_decode_end(struct uvc_video_device *video,
476 struct uvc_buffer *buf, const __u8 *data, int len)
478 /* Mark the buffer as done if the EOF marker is set. */
479 if (data[1] & UVC_STREAM_EOF && buf->buf.bytesused != 0) {
480 uvc_trace(UVC_TRACE_FRAME, "Frame complete (EOF found).\n");
482 uvc_trace(UVC_TRACE_FRAME, "EOF in empty payload.\n");
483 buf->state = UVC_BUF_STATE_DONE;
484 if (video->dev->quirks & UVC_QUIRK_STREAM_NO_FID)
485 video->last_fid ^= UVC_STREAM_FID;
489 /* Video payload encoding is handled by uvc_video_encode_header() and
490 * uvc_video_encode_data(). Only bulk transfers are currently supported.
492 * uvc_video_encode_header is called at the start of a payload. It adds header
493 * data to the transfer buffer and returns the header size. As the only known
494 * UVC output device transfers a whole frame in a single payload, the EOF bit
495 * is always set in the header.
497 * uvc_video_encode_data is called for every URB and copies the data from the
498 * video buffer to the transfer buffer.
500 static int uvc_video_encode_header(struct uvc_video_device *video,
501 struct uvc_buffer *buf, __u8 *data, int len)
503 data[0] = 2; /* Header length */
504 data[1] = UVC_STREAM_EOH | UVC_STREAM_EOF
505 | (video->last_fid & UVC_STREAM_FID);
509 static int uvc_video_encode_data(struct uvc_video_device *video,
510 struct uvc_buffer *buf, __u8 *data, int len)
512 struct uvc_video_queue *queue = &video->queue;
516 /* Copy video data to the URB buffer. */
517 mem = queue->mem + buf->buf.m.offset + queue->buf_used;
518 nbytes = min((unsigned int)len, buf->buf.bytesused - queue->buf_used);
519 nbytes = min(video->bulk.max_payload_size - video->bulk.payload_size,
521 memcpy(data, mem, nbytes);
523 queue->buf_used += nbytes;
528 /* ------------------------------------------------------------------------
533 * Completion handler for video URBs.
535 static void uvc_video_decode_isoc(struct urb *urb,
536 struct uvc_video_device *video, struct uvc_buffer *buf)
541 for (i = 0; i < urb->number_of_packets; ++i) {
542 if (urb->iso_frame_desc[i].status < 0) {
543 uvc_trace(UVC_TRACE_FRAME, "USB isochronous frame "
544 "lost (%d).\n", urb->iso_frame_desc[i].status);
548 /* Decode the payload header. */
549 mem = urb->transfer_buffer + urb->iso_frame_desc[i].offset;
551 ret = uvc_video_decode_start(video, buf, mem,
552 urb->iso_frame_desc[i].actual_length);
554 buf = uvc_queue_next_buffer(&video->queue, buf);
555 } while (ret == -EAGAIN);
560 /* Decode the payload data. */
561 uvc_video_decode_data(video, buf, mem + ret,
562 urb->iso_frame_desc[i].actual_length - ret);
564 /* Process the header again. */
565 uvc_video_decode_end(video, buf, mem,
566 urb->iso_frame_desc[i].actual_length);
568 if (buf->state == UVC_BUF_STATE_DONE ||
569 buf->state == UVC_BUF_STATE_ERROR)
570 buf = uvc_queue_next_buffer(&video->queue, buf);
574 static void uvc_video_decode_bulk(struct urb *urb,
575 struct uvc_video_device *video, struct uvc_buffer *buf)
580 if (urb->actual_length == 0)
583 mem = urb->transfer_buffer;
584 len = urb->actual_length;
585 video->bulk.payload_size += len;
587 /* If the URB is the first of its payload, decode and save the
590 if (video->bulk.header_size == 0 && !video->bulk.skip_payload) {
592 ret = uvc_video_decode_start(video, buf, mem, len);
594 buf = uvc_queue_next_buffer(&video->queue, buf);
595 } while (ret == -EAGAIN);
597 /* If an error occured skip the rest of the payload. */
598 if (ret < 0 || buf == NULL) {
599 video->bulk.skip_payload = 1;
601 memcpy(video->bulk.header, mem, ret);
602 video->bulk.header_size = ret;
609 /* The buffer queue might have been cancelled while a bulk transfer
610 * was in progress, so we can reach here with buf equal to NULL. Make
611 * sure buf is never dereferenced if NULL.
614 /* Process video data. */
615 if (!video->bulk.skip_payload && buf != NULL)
616 uvc_video_decode_data(video, buf, mem, len);
618 /* Detect the payload end by a URB smaller than the maximum size (or
619 * a payload size equal to the maximum) and process the header again.
621 if (urb->actual_length < urb->transfer_buffer_length ||
622 video->bulk.payload_size >= video->bulk.max_payload_size) {
623 if (!video->bulk.skip_payload && buf != NULL) {
624 uvc_video_decode_end(video, buf, video->bulk.header,
625 video->bulk.payload_size);
626 if (buf->state == UVC_BUF_STATE_DONE ||
627 buf->state == UVC_BUF_STATE_ERROR)
628 buf = uvc_queue_next_buffer(&video->queue, buf);
631 video->bulk.header_size = 0;
632 video->bulk.skip_payload = 0;
633 video->bulk.payload_size = 0;
637 static void uvc_video_encode_bulk(struct urb *urb,
638 struct uvc_video_device *video, struct uvc_buffer *buf)
640 u8 *mem = urb->transfer_buffer;
641 int len = video->urb_size, ret;
644 urb->transfer_buffer_length = 0;
648 /* If the URB is the first of its payload, add the header. */
649 if (video->bulk.header_size == 0) {
650 ret = uvc_video_encode_header(video, buf, mem, len);
651 video->bulk.header_size = ret;
652 video->bulk.payload_size += ret;
657 /* Process video data. */
658 ret = uvc_video_encode_data(video, buf, mem, len);
660 video->bulk.payload_size += ret;
663 if (buf->buf.bytesused == video->queue.buf_used ||
664 video->bulk.payload_size == video->bulk.max_payload_size) {
665 if (buf->buf.bytesused == video->queue.buf_used) {
666 video->queue.buf_used = 0;
667 buf->state = UVC_BUF_STATE_DONE;
668 uvc_queue_next_buffer(&video->queue, buf);
669 video->last_fid ^= UVC_STREAM_FID;
672 video->bulk.header_size = 0;
673 video->bulk.payload_size = 0;
676 urb->transfer_buffer_length = video->urb_size - len;
679 static void uvc_video_complete(struct urb *urb)
681 struct uvc_video_device *video = urb->context;
682 struct uvc_video_queue *queue = &video->queue;
683 struct uvc_buffer *buf = NULL;
687 switch (urb->status) {
692 uvc_printk(KERN_WARNING, "Non-zero status (%d) in video "
693 "completion handler.\n", urb->status);
695 case -ENOENT: /* usb_kill_urb() called. */
699 case -ECONNRESET: /* usb_unlink_urb() called. */
700 case -ESHUTDOWN: /* The endpoint is being disabled. */
701 uvc_queue_cancel(queue, urb->status == -ESHUTDOWN);
705 spin_lock_irqsave(&queue->irqlock, flags);
706 if (!list_empty(&queue->irqqueue))
707 buf = list_first_entry(&queue->irqqueue, struct uvc_buffer,
709 spin_unlock_irqrestore(&queue->irqlock, flags);
711 video->decode(urb, video, buf);
713 if ((ret = usb_submit_urb(urb, GFP_ATOMIC)) < 0) {
714 uvc_printk(KERN_ERR, "Failed to resubmit video URB (%d).\n",
720 * Free transfer buffers.
722 static void uvc_free_urb_buffers(struct uvc_video_device *video)
726 for (i = 0; i < UVC_URBS; ++i) {
727 if (video->urb_buffer[i]) {
728 usb_buffer_free(video->dev->udev, video->urb_size,
729 video->urb_buffer[i], video->urb_dma[i]);
730 video->urb_buffer[i] = NULL;
738 * Allocate transfer buffers. This function can be called with buffers
739 * already allocated when resuming from suspend, in which case it will
740 * return without touching the buffers.
742 * Limit the buffer size to UVC_MAX_PACKETS bulk/isochronous packets. If the
743 * system is too low on memory try successively smaller numbers of packets
744 * until allocation succeeds.
746 * Return the number of allocated packets on success or 0 when out of memory.
748 static int uvc_alloc_urb_buffers(struct uvc_video_device *video,
749 unsigned int size, unsigned int psize, gfp_t gfp_flags)
751 unsigned int npackets;
754 /* Buffers are already allocated, bail out. */
756 return video->urb_size / psize;
758 /* Compute the number of packets. Bulk endpoints might transfer UVC
759 * payloads accross multiple URBs.
761 npackets = DIV_ROUND_UP(size, psize);
762 if (npackets > UVC_MAX_PACKETS)
763 npackets = UVC_MAX_PACKETS;
765 /* Retry allocations until one succeed. */
766 for (; npackets > 1; npackets /= 2) {
767 for (i = 0; i < UVC_URBS; ++i) {
768 video->urb_buffer[i] = usb_buffer_alloc(
769 video->dev->udev, psize * npackets,
770 gfp_flags | __GFP_NOWARN, &video->urb_dma[i]);
771 if (!video->urb_buffer[i]) {
772 uvc_free_urb_buffers(video);
778 video->urb_size = psize * npackets;
787 * Uninitialize isochronous/bulk URBs and free transfer buffers.
789 static void uvc_uninit_video(struct uvc_video_device *video, int free_buffers)
794 for (i = 0; i < UVC_URBS; ++i) {
795 if ((urb = video->urb[i]) == NULL)
800 video->urb[i] = NULL;
804 uvc_free_urb_buffers(video);
808 * Initialize isochronous URBs and allocate transfer buffers. The packet size
809 * is given by the endpoint.
811 static int uvc_init_video_isoc(struct uvc_video_device *video,
812 struct usb_host_endpoint *ep, gfp_t gfp_flags)
815 unsigned int npackets, i, j;
819 psize = le16_to_cpu(ep->desc.wMaxPacketSize);
820 psize = (psize & 0x07ff) * (1 + ((psize >> 11) & 3));
821 size = video->streaming->ctrl.dwMaxVideoFrameSize;
823 npackets = uvc_alloc_urb_buffers(video, size, psize, gfp_flags);
827 size = npackets * psize;
829 for (i = 0; i < UVC_URBS; ++i) {
830 urb = usb_alloc_urb(npackets, gfp_flags);
832 uvc_uninit_video(video, 1);
836 urb->dev = video->dev->udev;
837 urb->context = video;
838 urb->pipe = usb_rcvisocpipe(video->dev->udev,
839 ep->desc.bEndpointAddress);
840 urb->transfer_flags = URB_ISO_ASAP | URB_NO_TRANSFER_DMA_MAP;
841 urb->interval = ep->desc.bInterval;
842 urb->transfer_buffer = video->urb_buffer[i];
843 urb->transfer_dma = video->urb_dma[i];
844 urb->complete = uvc_video_complete;
845 urb->number_of_packets = npackets;
846 urb->transfer_buffer_length = size;
848 for (j = 0; j < npackets; ++j) {
849 urb->iso_frame_desc[j].offset = j * psize;
850 urb->iso_frame_desc[j].length = psize;
860 * Initialize bulk URBs and allocate transfer buffers. The packet size is
861 * given by the endpoint.
863 static int uvc_init_video_bulk(struct uvc_video_device *video,
864 struct usb_host_endpoint *ep, gfp_t gfp_flags)
867 unsigned int npackets, pipe, i;
871 psize = le16_to_cpu(ep->desc.wMaxPacketSize) & 0x07ff;
872 size = video->streaming->ctrl.dwMaxPayloadTransferSize;
873 video->bulk.max_payload_size = size;
875 npackets = uvc_alloc_urb_buffers(video, size, psize, gfp_flags);
879 size = npackets * psize;
881 if (usb_endpoint_dir_in(&ep->desc))
882 pipe = usb_rcvbulkpipe(video->dev->udev,
883 ep->desc.bEndpointAddress);
885 pipe = usb_sndbulkpipe(video->dev->udev,
886 ep->desc.bEndpointAddress);
888 if (video->streaming->type == V4L2_BUF_TYPE_VIDEO_OUTPUT)
891 for (i = 0; i < UVC_URBS; ++i) {
892 urb = usb_alloc_urb(0, gfp_flags);
894 uvc_uninit_video(video, 1);
898 usb_fill_bulk_urb(urb, video->dev->udev, pipe,
899 video->urb_buffer[i], size, uvc_video_complete,
901 urb->transfer_flags = URB_NO_TRANSFER_DMA_MAP;
902 urb->transfer_dma = video->urb_dma[i];
911 * Initialize isochronous/bulk URBs and allocate transfer buffers.
913 static int uvc_init_video(struct uvc_video_device *video, gfp_t gfp_flags)
915 struct usb_interface *intf = video->streaming->intf;
916 struct usb_host_interface *alts;
917 struct usb_host_endpoint *ep = NULL;
918 int intfnum = video->streaming->intfnum;
919 unsigned int bandwidth, psize, i;
922 video->last_fid = -1;
923 video->bulk.header_size = 0;
924 video->bulk.skip_payload = 0;
925 video->bulk.payload_size = 0;
927 if (intf->num_altsetting > 1) {
928 /* Isochronous endpoint, select the alternate setting. */
929 bandwidth = video->streaming->ctrl.dwMaxPayloadTransferSize;
931 if (bandwidth == 0) {
932 uvc_printk(KERN_WARNING, "device %s requested null "
933 "bandwidth, defaulting to lowest.\n",
938 for (i = 0; i < intf->num_altsetting; ++i) {
939 alts = &intf->altsetting[i];
940 ep = uvc_find_endpoint(alts,
941 video->streaming->header.bEndpointAddress);
945 /* Check if the bandwidth is high enough. */
946 psize = le16_to_cpu(ep->desc.wMaxPacketSize);
947 psize = (psize & 0x07ff) * (1 + ((psize >> 11) & 3));
948 if (psize >= bandwidth)
952 if (i >= intf->num_altsetting)
955 if ((ret = usb_set_interface(video->dev->udev, intfnum, i)) < 0)
958 ret = uvc_init_video_isoc(video, ep, gfp_flags);
960 /* Bulk endpoint, proceed to URB initialization. */
961 ep = uvc_find_endpoint(&intf->altsetting[0],
962 video->streaming->header.bEndpointAddress);
966 ret = uvc_init_video_bulk(video, ep, gfp_flags);
972 /* Submit the URBs. */
973 for (i = 0; i < UVC_URBS; ++i) {
974 if ((ret = usb_submit_urb(video->urb[i], gfp_flags)) < 0) {
975 uvc_printk(KERN_ERR, "Failed to submit URB %u "
977 uvc_uninit_video(video, 1);
985 /* --------------------------------------------------------------------------
990 * Stop streaming without disabling the video queue.
992 * To let userspace applications resume without trouble, we must not touch the
993 * video buffers in any way. We mark the device as frozen to make sure the URB
994 * completion handler won't try to cancel the queue when we kill the URBs.
996 int uvc_video_suspend(struct uvc_video_device *video)
998 if (!uvc_queue_streaming(&video->queue))
1002 uvc_uninit_video(video, 0);
1003 usb_set_interface(video->dev->udev, video->streaming->intfnum, 0);
1008 * Reconfigure the video interface and restart streaming if it was enabled
1011 * If an error occurs, disable the video queue. This will wake all pending
1012 * buffers, making sure userspace applications are notified of the problem
1013 * instead of waiting forever.
1015 int uvc_video_resume(struct uvc_video_device *video)
1021 if ((ret = uvc_commit_video(video, &video->streaming->ctrl)) < 0) {
1022 uvc_queue_enable(&video->queue, 0);
1026 if (!uvc_queue_streaming(&video->queue))
1029 if ((ret = uvc_init_video(video, GFP_NOIO)) < 0)
1030 uvc_queue_enable(&video->queue, 0);
1035 /* ------------------------------------------------------------------------
1040 * Initialize the UVC video device by switching to alternate setting 0 and
1041 * retrieve the default format.
1043 * Some cameras (namely the Fuji Finepix) set the format and frame
1044 * indexes to zero. The UVC standard doesn't clearly make this a spec
1045 * violation, so try to silently fix the values if possible.
1047 * This function is called before registering the device with V4L.
1049 int uvc_video_init(struct uvc_video_device *video)
1051 struct uvc_streaming_control *probe = &video->streaming->ctrl;
1052 struct uvc_format *format = NULL;
1053 struct uvc_frame *frame = NULL;
1057 if (video->streaming->nformats == 0) {
1058 uvc_printk(KERN_INFO, "No supported video formats found.\n");
1062 /* Alternate setting 0 should be the default, yet the XBox Live Vision
1063 * Cam (and possibly other devices) crash or otherwise misbehave if
1064 * they don't receive a SET_INTERFACE request before any other video
1067 usb_set_interface(video->dev->udev, video->streaming->intfnum, 0);
1069 /* Set the streaming probe control with default streaming parameters
1070 * retrieved from the device. Webcams that don't suport GET_DEF
1071 * requests on the probe control will just keep their current streaming
1074 if (uvc_get_video_ctrl(video, probe, 1, UVC_GET_DEF) == 0)
1075 uvc_set_video_ctrl(video, probe, 1);
1077 /* Initialize the streaming parameters with the probe control current
1078 * value. This makes sure SET_CUR requests on the streaming commit
1079 * control will always use values retrieved from a successful GET_CUR
1080 * request on the probe control, as required by the UVC specification.
1082 ret = uvc_get_video_ctrl(video, probe, 1, UVC_GET_CUR);
1086 /* Check if the default format descriptor exists. Use the first
1087 * available format otherwise.
1089 for (i = video->streaming->nformats; i > 0; --i) {
1090 format = &video->streaming->format[i-1];
1091 if (format->index == probe->bFormatIndex)
1095 if (format->nframes == 0) {
1096 uvc_printk(KERN_INFO, "No frame descriptor found for the "
1097 "default format.\n");
1101 /* Zero bFrameIndex might be correct. Stream-based formats (including
1102 * MPEG-2 TS and DV) do not support frames but have a dummy frame
1103 * descriptor with bFrameIndex set to zero. If the default frame
1104 * descriptor is not found, use the first available frame.
1106 for (i = format->nframes; i > 0; --i) {
1107 frame = &format->frame[i-1];
1108 if (frame->bFrameIndex == probe->bFrameIndex)
1112 probe->bFormatIndex = format->index;
1113 probe->bFrameIndex = frame->bFrameIndex;
1115 video->streaming->cur_format = format;
1116 video->streaming->cur_frame = frame;
1117 atomic_set(&video->active, 0);
1119 /* Select the video decoding function */
1120 if (video->streaming->type == V4L2_BUF_TYPE_VIDEO_CAPTURE) {
1121 if (video->dev->quirks & UVC_QUIRK_BUILTIN_ISIGHT)
1122 video->decode = uvc_video_decode_isight;
1123 else if (video->streaming->intf->num_altsetting > 1)
1124 video->decode = uvc_video_decode_isoc;
1126 video->decode = uvc_video_decode_bulk;
1128 if (video->streaming->intf->num_altsetting == 1)
1129 video->decode = uvc_video_encode_bulk;
1131 uvc_printk(KERN_INFO, "Isochronous endpoints are not "
1132 "supported for video output devices.\n");
1141 * Enable or disable the video stream.
1143 int uvc_video_enable(struct uvc_video_device *video, int enable)
1148 uvc_uninit_video(video, 1);
1149 usb_set_interface(video->dev->udev,
1150 video->streaming->intfnum, 0);
1151 uvc_queue_enable(&video->queue, 0);
1155 if ((video->streaming->cur_format->flags & UVC_FMT_FLAG_COMPRESSED) ||
1157 video->queue.flags &= ~UVC_QUEUE_DROP_INCOMPLETE;
1159 video->queue.flags |= UVC_QUEUE_DROP_INCOMPLETE;
1161 if ((ret = uvc_queue_enable(&video->queue, 1)) < 0)
1164 /* Commit the streaming parameters. */
1165 if ((ret = uvc_commit_video(video, &video->streaming->ctrl)) < 0)
1168 return uvc_init_video(video, GFP_KERNEL);