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 <asm/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;
93 struct uvc_frame *frame = NULL;
96 if (ctrl->bFormatIndex <= 0 ||
97 ctrl->bFormatIndex > stream->nformats)
100 format = &stream->format[ctrl->bFormatIndex - 1];
102 for (i = 0; i < format->nframes; ++i) {
103 if (format->frame[i].bFrameIndex == ctrl->bFrameIndex) {
104 frame = &format->frame[i];
112 if (!(format->flags & UVC_FMT_FLAG_COMPRESSED) ||
113 (ctrl->dwMaxVideoFrameSize == 0 &&
114 stream->dev->uvc_version < 0x0110))
115 ctrl->dwMaxVideoFrameSize =
116 frame->dwMaxVideoFrameBufferSize;
118 if (!(format->flags & UVC_FMT_FLAG_COMPRESSED) &&
119 stream->dev->quirks & UVC_QUIRK_FIX_BANDWIDTH &&
120 stream->intf->num_altsetting > 1) {
124 interval = (ctrl->dwFrameInterval > 100000)
125 ? ctrl->dwFrameInterval
126 : frame->dwFrameInterval[0];
128 /* Compute a bandwidth estimation by multiplying the frame
129 * size by the number of video frames per second, divide the
130 * result by the number of USB frames (or micro-frames for
131 * high-speed devices) per second and add the UVC header size
132 * (assumed to be 12 bytes long).
134 bandwidth = frame->wWidth * frame->wHeight / 8 * format->bpp;
135 bandwidth *= 10000000 / interval + 1;
137 if (stream->dev->udev->speed == USB_SPEED_HIGH)
141 /* The bandwidth estimate is too low for many cameras. Don't use
142 * maximum packet sizes lower than 1024 bytes to try and work
143 * around the problem. According to measurements done on two
144 * different camera models, the value is high enough to get most
145 * resolutions working while not preventing two simultaneous
146 * VGA streams at 15 fps.
148 bandwidth = max_t(u32, bandwidth, 1024);
150 ctrl->dwMaxPayloadTransferSize = bandwidth;
154 static int uvc_get_video_ctrl(struct uvc_streaming *stream,
155 struct uvc_streaming_control *ctrl, int probe, __u8 query)
161 size = stream->dev->uvc_version >= 0x0110 ? 34 : 26;
162 if ((stream->dev->quirks & UVC_QUIRK_PROBE_DEF) &&
163 query == UVC_GET_DEF)
166 data = kmalloc(size, GFP_KERNEL);
170 ret = __uvc_query_ctrl(stream->dev, query, 0, stream->intfnum,
171 probe ? UVC_VS_PROBE_CONTROL : UVC_VS_COMMIT_CONTROL, data,
172 size, uvc_timeout_param);
174 if ((query == UVC_GET_MIN || query == UVC_GET_MAX) && ret == 2) {
175 /* Some cameras, mostly based on Bison Electronics chipsets,
176 * answer a GET_MIN or GET_MAX request with the wCompQuality
179 uvc_warn_once(stream->dev, UVC_WARN_MINMAX, "UVC non "
180 "compliance - GET_MIN/MAX(PROBE) incorrectly "
181 "supported. Enabling workaround.\n");
182 memset(ctrl, 0, sizeof *ctrl);
183 ctrl->wCompQuality = le16_to_cpup((__le16 *)data);
186 } else if (query == UVC_GET_DEF && probe == 1 && ret != size) {
187 /* Many cameras don't support the GET_DEF request on their
188 * video probe control. Warn once and return, the caller will
189 * fall back to GET_CUR.
191 uvc_warn_once(stream->dev, UVC_WARN_PROBE_DEF, "UVC non "
192 "compliance - GET_DEF(PROBE) not supported. "
193 "Enabling workaround.\n");
196 } else if (ret != size) {
197 uvc_printk(KERN_ERR, "Failed to query (%u) UVC %s control : "
198 "%d (exp. %u).\n", query, probe ? "probe" : "commit",
204 ctrl->bmHint = le16_to_cpup((__le16 *)&data[0]);
205 ctrl->bFormatIndex = data[2];
206 ctrl->bFrameIndex = data[3];
207 ctrl->dwFrameInterval = le32_to_cpup((__le32 *)&data[4]);
208 ctrl->wKeyFrameRate = le16_to_cpup((__le16 *)&data[8]);
209 ctrl->wPFrameRate = le16_to_cpup((__le16 *)&data[10]);
210 ctrl->wCompQuality = le16_to_cpup((__le16 *)&data[12]);
211 ctrl->wCompWindowSize = le16_to_cpup((__le16 *)&data[14]);
212 ctrl->wDelay = le16_to_cpup((__le16 *)&data[16]);
213 ctrl->dwMaxVideoFrameSize = get_unaligned_le32(&data[18]);
214 ctrl->dwMaxPayloadTransferSize = get_unaligned_le32(&data[22]);
217 ctrl->dwClockFrequency = get_unaligned_le32(&data[26]);
218 ctrl->bmFramingInfo = data[30];
219 ctrl->bPreferedVersion = data[31];
220 ctrl->bMinVersion = data[32];
221 ctrl->bMaxVersion = data[33];
223 ctrl->dwClockFrequency = stream->dev->clock_frequency;
224 ctrl->bmFramingInfo = 0;
225 ctrl->bPreferedVersion = 0;
226 ctrl->bMinVersion = 0;
227 ctrl->bMaxVersion = 0;
230 /* Some broken devices return null or wrong dwMaxVideoFrameSize and
231 * dwMaxPayloadTransferSize fields. Try to get the value from the
232 * format and frame descriptors.
234 uvc_fixup_video_ctrl(stream, ctrl);
242 static int uvc_set_video_ctrl(struct uvc_streaming *stream,
243 struct uvc_streaming_control *ctrl, int probe)
249 size = stream->dev->uvc_version >= 0x0110 ? 34 : 26;
250 data = kzalloc(size, GFP_KERNEL);
254 *(__le16 *)&data[0] = cpu_to_le16(ctrl->bmHint);
255 data[2] = ctrl->bFormatIndex;
256 data[3] = ctrl->bFrameIndex;
257 *(__le32 *)&data[4] = cpu_to_le32(ctrl->dwFrameInterval);
258 *(__le16 *)&data[8] = cpu_to_le16(ctrl->wKeyFrameRate);
259 *(__le16 *)&data[10] = cpu_to_le16(ctrl->wPFrameRate);
260 *(__le16 *)&data[12] = cpu_to_le16(ctrl->wCompQuality);
261 *(__le16 *)&data[14] = cpu_to_le16(ctrl->wCompWindowSize);
262 *(__le16 *)&data[16] = cpu_to_le16(ctrl->wDelay);
263 put_unaligned_le32(ctrl->dwMaxVideoFrameSize, &data[18]);
264 put_unaligned_le32(ctrl->dwMaxPayloadTransferSize, &data[22]);
267 put_unaligned_le32(ctrl->dwClockFrequency, &data[26]);
268 data[30] = ctrl->bmFramingInfo;
269 data[31] = ctrl->bPreferedVersion;
270 data[32] = ctrl->bMinVersion;
271 data[33] = ctrl->bMaxVersion;
274 ret = __uvc_query_ctrl(stream->dev, UVC_SET_CUR, 0, stream->intfnum,
275 probe ? UVC_VS_PROBE_CONTROL : UVC_VS_COMMIT_CONTROL, data,
276 size, uvc_timeout_param);
278 uvc_printk(KERN_ERR, "Failed to set UVC %s control : "
279 "%d (exp. %u).\n", probe ? "probe" : "commit",
288 int uvc_probe_video(struct uvc_streaming *stream,
289 struct uvc_streaming_control *probe)
291 struct uvc_streaming_control probe_min, probe_max;
296 mutex_lock(&stream->mutex);
298 /* Perform probing. The device should adjust the requested values
299 * according to its capabilities. However, some devices, namely the
300 * first generation UVC Logitech webcams, don't implement the Video
301 * Probe control properly, and just return the needed bandwidth. For
302 * that reason, if the needed bandwidth exceeds the maximum available
303 * bandwidth, try to lower the quality.
305 ret = uvc_set_video_ctrl(stream, probe, 1);
309 /* Get the minimum and maximum values for compression settings. */
310 if (!(stream->dev->quirks & UVC_QUIRK_PROBE_MINMAX)) {
311 ret = uvc_get_video_ctrl(stream, &probe_min, 1, UVC_GET_MIN);
314 ret = uvc_get_video_ctrl(stream, &probe_max, 1, UVC_GET_MAX);
318 probe->wCompQuality = probe_max.wCompQuality;
321 for (i = 0; i < 2; ++i) {
322 ret = uvc_set_video_ctrl(stream, probe, 1);
325 ret = uvc_get_video_ctrl(stream, probe, 1, UVC_GET_CUR);
329 if (stream->intf->num_altsetting == 1)
332 bandwidth = probe->dwMaxPayloadTransferSize;
333 if (bandwidth <= stream->maxpsize)
336 if (stream->dev->quirks & UVC_QUIRK_PROBE_MINMAX) {
341 /* TODO: negotiate compression parameters */
342 probe->wKeyFrameRate = probe_min.wKeyFrameRate;
343 probe->wPFrameRate = probe_min.wPFrameRate;
344 probe->wCompQuality = probe_max.wCompQuality;
345 probe->wCompWindowSize = probe_min.wCompWindowSize;
349 mutex_unlock(&stream->mutex);
353 int uvc_commit_video(struct uvc_streaming *stream,
354 struct uvc_streaming_control *probe)
356 return uvc_set_video_ctrl(stream, probe, 0);
359 /* ------------------------------------------------------------------------
363 /* Values for bmHeaderInfo (Video and Still Image Payload Headers, 2.4.3.3) */
364 #define UVC_STREAM_EOH (1 << 7)
365 #define UVC_STREAM_ERR (1 << 6)
366 #define UVC_STREAM_STI (1 << 5)
367 #define UVC_STREAM_RES (1 << 4)
368 #define UVC_STREAM_SCR (1 << 3)
369 #define UVC_STREAM_PTS (1 << 2)
370 #define UVC_STREAM_EOF (1 << 1)
371 #define UVC_STREAM_FID (1 << 0)
373 /* Video payload decoding is handled by uvc_video_decode_start(),
374 * uvc_video_decode_data() and uvc_video_decode_end().
376 * uvc_video_decode_start is called with URB data at the start of a bulk or
377 * isochronous payload. It processes header data and returns the header size
378 * in bytes if successful. If an error occurs, it returns a negative error
379 * code. The following error codes have special meanings.
381 * - EAGAIN informs the caller that the current video buffer should be marked
382 * as done, and that the function should be called again with the same data
383 * and a new video buffer. This is used when end of frame conditions can be
384 * reliably detected at the beginning of the next frame only.
386 * If an error other than -EAGAIN is returned, the caller will drop the current
387 * payload. No call to uvc_video_decode_data and uvc_video_decode_end will be
388 * made until the next payload. -ENODATA can be used to drop the current
389 * payload if no other error code is appropriate.
391 * uvc_video_decode_data is called for every URB with URB data. It copies the
392 * data to the video buffer.
394 * uvc_video_decode_end is called with header data at the end of a bulk or
395 * isochronous payload. It performs any additional header data processing and
396 * returns 0 or a negative error code if an error occured. As header data have
397 * already been processed by uvc_video_decode_start, this functions isn't
398 * required to perform sanity checks a second time.
400 * For isochronous transfers where a payload is always transfered in a single
401 * URB, the three functions will be called in a row.
403 * To let the decoder process header data and update its internal state even
404 * when no video buffer is available, uvc_video_decode_start must be prepared
405 * to be called with a NULL buf parameter. uvc_video_decode_data and
406 * uvc_video_decode_end will never be called with a NULL buffer.
408 static int uvc_video_decode_start(struct uvc_streaming *stream,
409 struct uvc_buffer *buf, const __u8 *data, int len)
414 * - packet must be at least 2 bytes long
415 * - bHeaderLength value must be at least 2 bytes (see above)
416 * - bHeaderLength value can't be larger than the packet size.
418 if (len < 2 || data[0] < 2 || data[0] > len)
421 /* Skip payloads marked with the error bit ("error frames"). */
422 if (data[1] & UVC_STREAM_ERR) {
423 uvc_trace(UVC_TRACE_FRAME, "Dropping payload (error bit "
428 fid = data[1] & UVC_STREAM_FID;
430 /* Increase the sequence number regardless of any buffer states, so
431 * that discontinuous sequence numbers always indicate lost frames.
433 if (stream->last_fid != fid)
436 /* Store the payload FID bit and return immediately when the buffer is
440 stream->last_fid = fid;
444 /* Synchronize to the input stream by waiting for the FID bit to be
445 * toggled when the the buffer state is not UVC_BUF_STATE_ACTIVE.
446 * stream->last_fid is initialized to -1, so the first isochronous
447 * frame will always be in sync.
449 * If the device doesn't toggle the FID bit, invert stream->last_fid
450 * when the EOF bit is set to force synchronisation on the next packet.
452 if (buf->state != UVC_BUF_STATE_ACTIVE) {
455 if (fid == stream->last_fid) {
456 uvc_trace(UVC_TRACE_FRAME, "Dropping payload (out of "
458 if ((stream->dev->quirks & UVC_QUIRK_STREAM_NO_FID) &&
459 (data[1] & UVC_STREAM_EOF))
460 stream->last_fid ^= UVC_STREAM_FID;
464 if (uvc_clock_param == CLOCK_MONOTONIC)
467 ktime_get_real_ts(&ts);
469 buf->buf.sequence = stream->sequence;
470 buf->buf.timestamp.tv_sec = ts.tv_sec;
471 buf->buf.timestamp.tv_usec = ts.tv_nsec / NSEC_PER_USEC;
473 /* TODO: Handle PTS and SCR. */
474 buf->state = UVC_BUF_STATE_ACTIVE;
477 /* Mark the buffer as done if we're at the beginning of a new frame.
478 * End of frame detection is better implemented by checking the EOF
479 * bit (FID bit toggling is delayed by one frame compared to the EOF
480 * bit), but some devices don't set the bit at end of frame (and the
481 * last payload can be lost anyway). We thus must check if the FID has
484 * stream->last_fid is initialized to -1, so the first isochronous
485 * frame will never trigger an end of frame detection.
487 * Empty buffers (bytesused == 0) don't trigger end of frame detection
488 * as it doesn't make sense to return an empty buffer. This also
489 * avoids detecting end of frame conditions at FID toggling if the
490 * previous payload had the EOF bit set.
492 if (fid != stream->last_fid && buf->buf.bytesused != 0) {
493 uvc_trace(UVC_TRACE_FRAME, "Frame complete (FID bit "
495 buf->state = UVC_BUF_STATE_READY;
499 stream->last_fid = fid;
504 static void uvc_video_decode_data(struct uvc_streaming *stream,
505 struct uvc_buffer *buf, const __u8 *data, int len)
507 struct uvc_video_queue *queue = &stream->queue;
508 unsigned int maxlen, nbytes;
514 /* Copy the video data to the buffer. */
515 maxlen = buf->buf.length - buf->buf.bytesused;
516 mem = queue->mem + buf->buf.m.offset + buf->buf.bytesused;
517 nbytes = min((unsigned int)len, maxlen);
518 memcpy(mem, data, nbytes);
519 buf->buf.bytesused += nbytes;
521 /* Complete the current frame if the buffer size was exceeded. */
523 uvc_trace(UVC_TRACE_FRAME, "Frame complete (overflow).\n");
524 buf->state = UVC_BUF_STATE_READY;
528 static void uvc_video_decode_end(struct uvc_streaming *stream,
529 struct uvc_buffer *buf, const __u8 *data, int len)
531 /* Mark the buffer as done if the EOF marker is set. */
532 if (data[1] & UVC_STREAM_EOF && buf->buf.bytesused != 0) {
533 uvc_trace(UVC_TRACE_FRAME, "Frame complete (EOF found).\n");
535 uvc_trace(UVC_TRACE_FRAME, "EOF in empty payload.\n");
536 buf->state = UVC_BUF_STATE_READY;
537 if (stream->dev->quirks & UVC_QUIRK_STREAM_NO_FID)
538 stream->last_fid ^= UVC_STREAM_FID;
542 /* Video payload encoding is handled by uvc_video_encode_header() and
543 * uvc_video_encode_data(). Only bulk transfers are currently supported.
545 * uvc_video_encode_header is called at the start of a payload. It adds header
546 * data to the transfer buffer and returns the header size. As the only known
547 * UVC output device transfers a whole frame in a single payload, the EOF bit
548 * is always set in the header.
550 * uvc_video_encode_data is called for every URB and copies the data from the
551 * video buffer to the transfer buffer.
553 static int uvc_video_encode_header(struct uvc_streaming *stream,
554 struct uvc_buffer *buf, __u8 *data, int len)
556 data[0] = 2; /* Header length */
557 data[1] = UVC_STREAM_EOH | UVC_STREAM_EOF
558 | (stream->last_fid & UVC_STREAM_FID);
562 static int uvc_video_encode_data(struct uvc_streaming *stream,
563 struct uvc_buffer *buf, __u8 *data, int len)
565 struct uvc_video_queue *queue = &stream->queue;
569 /* Copy video data to the URB buffer. */
570 mem = queue->mem + buf->buf.m.offset + queue->buf_used;
571 nbytes = min((unsigned int)len, buf->buf.bytesused - queue->buf_used);
572 nbytes = min(stream->bulk.max_payload_size - stream->bulk.payload_size,
574 memcpy(data, mem, nbytes);
576 queue->buf_used += nbytes;
581 /* ------------------------------------------------------------------------
586 * Completion handler for video URBs.
588 static void uvc_video_decode_isoc(struct urb *urb, struct uvc_streaming *stream,
589 struct uvc_buffer *buf)
594 for (i = 0; i < urb->number_of_packets; ++i) {
595 if (urb->iso_frame_desc[i].status < 0) {
596 uvc_trace(UVC_TRACE_FRAME, "USB isochronous frame "
597 "lost (%d).\n", urb->iso_frame_desc[i].status);
598 /* Mark the buffer as faulty. */
604 /* Decode the payload header. */
605 mem = urb->transfer_buffer + urb->iso_frame_desc[i].offset;
607 ret = uvc_video_decode_start(stream, buf, mem,
608 urb->iso_frame_desc[i].actual_length);
610 buf = uvc_queue_next_buffer(&stream->queue,
612 } while (ret == -EAGAIN);
617 /* Decode the payload data. */
618 uvc_video_decode_data(stream, buf, mem + ret,
619 urb->iso_frame_desc[i].actual_length - ret);
621 /* Process the header again. */
622 uvc_video_decode_end(stream, buf, mem,
623 urb->iso_frame_desc[i].actual_length);
625 if (buf->state == UVC_BUF_STATE_READY) {
626 if (buf->buf.length != buf->buf.bytesused &&
627 !(stream->cur_format->flags &
628 UVC_FMT_FLAG_COMPRESSED))
631 buf = uvc_queue_next_buffer(&stream->queue, buf);
636 static void uvc_video_decode_bulk(struct urb *urb, struct uvc_streaming *stream,
637 struct uvc_buffer *buf)
642 if (urb->actual_length == 0)
645 mem = urb->transfer_buffer;
646 len = urb->actual_length;
647 stream->bulk.payload_size += len;
649 /* If the URB is the first of its payload, decode and save the
652 if (stream->bulk.header_size == 0 && !stream->bulk.skip_payload) {
654 ret = uvc_video_decode_start(stream, buf, mem, len);
656 buf = uvc_queue_next_buffer(&stream->queue,
658 } while (ret == -EAGAIN);
660 /* If an error occured skip the rest of the payload. */
661 if (ret < 0 || buf == NULL) {
662 stream->bulk.skip_payload = 1;
664 memcpy(stream->bulk.header, mem, ret);
665 stream->bulk.header_size = ret;
672 /* The buffer queue might have been cancelled while a bulk transfer
673 * was in progress, so we can reach here with buf equal to NULL. Make
674 * sure buf is never dereferenced if NULL.
677 /* Process video data. */
678 if (!stream->bulk.skip_payload && buf != NULL)
679 uvc_video_decode_data(stream, buf, mem, len);
681 /* Detect the payload end by a URB smaller than the maximum size (or
682 * a payload size equal to the maximum) and process the header again.
684 if (urb->actual_length < urb->transfer_buffer_length ||
685 stream->bulk.payload_size >= stream->bulk.max_payload_size) {
686 if (!stream->bulk.skip_payload && buf != NULL) {
687 uvc_video_decode_end(stream, buf, stream->bulk.header,
688 stream->bulk.payload_size);
689 if (buf->state == UVC_BUF_STATE_READY)
690 buf = uvc_queue_next_buffer(&stream->queue,
694 stream->bulk.header_size = 0;
695 stream->bulk.skip_payload = 0;
696 stream->bulk.payload_size = 0;
700 static void uvc_video_encode_bulk(struct urb *urb, struct uvc_streaming *stream,
701 struct uvc_buffer *buf)
703 u8 *mem = urb->transfer_buffer;
704 int len = stream->urb_size, ret;
707 urb->transfer_buffer_length = 0;
711 /* If the URB is the first of its payload, add the header. */
712 if (stream->bulk.header_size == 0) {
713 ret = uvc_video_encode_header(stream, buf, mem, len);
714 stream->bulk.header_size = ret;
715 stream->bulk.payload_size += ret;
720 /* Process video data. */
721 ret = uvc_video_encode_data(stream, buf, mem, len);
723 stream->bulk.payload_size += ret;
726 if (buf->buf.bytesused == stream->queue.buf_used ||
727 stream->bulk.payload_size == stream->bulk.max_payload_size) {
728 if (buf->buf.bytesused == stream->queue.buf_used) {
729 stream->queue.buf_used = 0;
730 buf->state = UVC_BUF_STATE_READY;
731 buf->buf.sequence = ++stream->sequence;
732 uvc_queue_next_buffer(&stream->queue, buf);
733 stream->last_fid ^= UVC_STREAM_FID;
736 stream->bulk.header_size = 0;
737 stream->bulk.payload_size = 0;
740 urb->transfer_buffer_length = stream->urb_size - len;
743 static void uvc_video_complete(struct urb *urb)
745 struct uvc_streaming *stream = urb->context;
746 struct uvc_video_queue *queue = &stream->queue;
747 struct uvc_buffer *buf = NULL;
751 switch (urb->status) {
756 uvc_printk(KERN_WARNING, "Non-zero status (%d) in video "
757 "completion handler.\n", urb->status);
759 case -ENOENT: /* usb_kill_urb() called. */
763 case -ECONNRESET: /* usb_unlink_urb() called. */
764 case -ESHUTDOWN: /* The endpoint is being disabled. */
765 uvc_queue_cancel(queue, urb->status == -ESHUTDOWN);
769 spin_lock_irqsave(&queue->irqlock, flags);
770 if (!list_empty(&queue->irqqueue))
771 buf = list_first_entry(&queue->irqqueue, struct uvc_buffer,
773 spin_unlock_irqrestore(&queue->irqlock, flags);
775 stream->decode(urb, stream, buf);
777 if ((ret = usb_submit_urb(urb, GFP_ATOMIC)) < 0) {
778 uvc_printk(KERN_ERR, "Failed to resubmit video URB (%d).\n",
784 * Free transfer buffers.
786 static void uvc_free_urb_buffers(struct uvc_streaming *stream)
790 for (i = 0; i < UVC_URBS; ++i) {
791 if (stream->urb_buffer[i]) {
792 usb_free_coherent(stream->dev->udev, stream->urb_size,
793 stream->urb_buffer[i], stream->urb_dma[i]);
794 stream->urb_buffer[i] = NULL;
798 stream->urb_size = 0;
802 * Allocate transfer buffers. This function can be called with buffers
803 * already allocated when resuming from suspend, in which case it will
804 * return without touching the buffers.
806 * Limit the buffer size to UVC_MAX_PACKETS bulk/isochronous packets. If the
807 * system is too low on memory try successively smaller numbers of packets
808 * until allocation succeeds.
810 * Return the number of allocated packets on success or 0 when out of memory.
812 static int uvc_alloc_urb_buffers(struct uvc_streaming *stream,
813 unsigned int size, unsigned int psize, gfp_t gfp_flags)
815 unsigned int npackets;
818 /* Buffers are already allocated, bail out. */
819 if (stream->urb_size)
820 return stream->urb_size / psize;
822 /* Compute the number of packets. Bulk endpoints might transfer UVC
823 * payloads accross multiple URBs.
825 npackets = DIV_ROUND_UP(size, psize);
826 if (npackets > UVC_MAX_PACKETS)
827 npackets = UVC_MAX_PACKETS;
829 /* Retry allocations until one succeed. */
830 for (; npackets > 1; npackets /= 2) {
831 for (i = 0; i < UVC_URBS; ++i) {
832 stream->urb_size = psize * npackets;
833 stream->urb_buffer[i] = usb_alloc_coherent(
834 stream->dev->udev, stream->urb_size,
835 gfp_flags | __GFP_NOWARN, &stream->urb_dma[i]);
836 if (!stream->urb_buffer[i]) {
837 uvc_free_urb_buffers(stream);
843 uvc_trace(UVC_TRACE_VIDEO, "Allocated %u URB buffers "
844 "of %ux%u bytes each.\n", UVC_URBS, npackets,
850 uvc_trace(UVC_TRACE_VIDEO, "Failed to allocate URB buffers (%u bytes "
851 "per packet).\n", psize);
856 * Uninitialize isochronous/bulk URBs and free transfer buffers.
858 static void uvc_uninit_video(struct uvc_streaming *stream, int free_buffers)
863 for (i = 0; i < UVC_URBS; ++i) {
864 urb = stream->urb[i];
870 stream->urb[i] = NULL;
874 uvc_free_urb_buffers(stream);
878 * Initialize isochronous URBs and allocate transfer buffers. The packet size
879 * is given by the endpoint.
881 static int uvc_init_video_isoc(struct uvc_streaming *stream,
882 struct usb_host_endpoint *ep, gfp_t gfp_flags)
885 unsigned int npackets, i, j;
889 psize = le16_to_cpu(ep->desc.wMaxPacketSize);
890 psize = (psize & 0x07ff) * (1 + ((psize >> 11) & 3));
891 size = stream->ctrl.dwMaxVideoFrameSize;
893 npackets = uvc_alloc_urb_buffers(stream, size, psize, gfp_flags);
897 size = npackets * psize;
899 for (i = 0; i < UVC_URBS; ++i) {
900 urb = usb_alloc_urb(npackets, gfp_flags);
902 uvc_uninit_video(stream, 1);
906 urb->dev = stream->dev->udev;
907 urb->context = stream;
908 urb->pipe = usb_rcvisocpipe(stream->dev->udev,
909 ep->desc.bEndpointAddress);
910 urb->transfer_flags = URB_ISO_ASAP | URB_NO_TRANSFER_DMA_MAP;
911 urb->interval = ep->desc.bInterval;
912 urb->transfer_buffer = stream->urb_buffer[i];
913 urb->transfer_dma = stream->urb_dma[i];
914 urb->complete = uvc_video_complete;
915 urb->number_of_packets = npackets;
916 urb->transfer_buffer_length = size;
918 for (j = 0; j < npackets; ++j) {
919 urb->iso_frame_desc[j].offset = j * psize;
920 urb->iso_frame_desc[j].length = psize;
923 stream->urb[i] = urb;
930 * Initialize bulk URBs and allocate transfer buffers. The packet size is
931 * given by the endpoint.
933 static int uvc_init_video_bulk(struct uvc_streaming *stream,
934 struct usb_host_endpoint *ep, gfp_t gfp_flags)
937 unsigned int npackets, pipe, i;
941 psize = le16_to_cpu(ep->desc.wMaxPacketSize) & 0x07ff;
942 size = stream->ctrl.dwMaxPayloadTransferSize;
943 stream->bulk.max_payload_size = size;
945 npackets = uvc_alloc_urb_buffers(stream, size, psize, gfp_flags);
949 size = npackets * psize;
951 if (usb_endpoint_dir_in(&ep->desc))
952 pipe = usb_rcvbulkpipe(stream->dev->udev,
953 ep->desc.bEndpointAddress);
955 pipe = usb_sndbulkpipe(stream->dev->udev,
956 ep->desc.bEndpointAddress);
958 if (stream->type == V4L2_BUF_TYPE_VIDEO_OUTPUT)
961 for (i = 0; i < UVC_URBS; ++i) {
962 urb = usb_alloc_urb(0, gfp_flags);
964 uvc_uninit_video(stream, 1);
968 usb_fill_bulk_urb(urb, stream->dev->udev, pipe,
969 stream->urb_buffer[i], size, uvc_video_complete,
971 urb->transfer_flags = URB_NO_TRANSFER_DMA_MAP;
972 urb->transfer_dma = stream->urb_dma[i];
974 stream->urb[i] = urb;
981 * Initialize isochronous/bulk URBs and allocate transfer buffers.
983 static int uvc_init_video(struct uvc_streaming *stream, gfp_t gfp_flags)
985 struct usb_interface *intf = stream->intf;
986 struct usb_host_endpoint *ep;
990 stream->sequence = -1;
991 stream->last_fid = -1;
992 stream->bulk.header_size = 0;
993 stream->bulk.skip_payload = 0;
994 stream->bulk.payload_size = 0;
996 if (intf->num_altsetting > 1) {
997 struct usb_host_endpoint *best_ep = NULL;
998 unsigned int best_psize = 3 * 1024;
999 unsigned int bandwidth;
1000 unsigned int uninitialized_var(altsetting);
1001 int intfnum = stream->intfnum;
1003 /* Isochronous endpoint, select the alternate setting. */
1004 bandwidth = stream->ctrl.dwMaxPayloadTransferSize;
1006 if (bandwidth == 0) {
1007 uvc_trace(UVC_TRACE_VIDEO, "Device requested null "
1008 "bandwidth, defaulting to lowest.\n");
1011 uvc_trace(UVC_TRACE_VIDEO, "Device requested %u "
1012 "B/frame bandwidth.\n", bandwidth);
1015 for (i = 0; i < intf->num_altsetting; ++i) {
1016 struct usb_host_interface *alts;
1019 alts = &intf->altsetting[i];
1020 ep = uvc_find_endpoint(alts,
1021 stream->header.bEndpointAddress);
1025 /* Check if the bandwidth is high enough. */
1026 psize = le16_to_cpu(ep->desc.wMaxPacketSize);
1027 psize = (psize & 0x07ff) * (1 + ((psize >> 11) & 3));
1028 if (psize >= bandwidth && psize <= best_psize) {
1035 if (best_ep == NULL) {
1036 uvc_trace(UVC_TRACE_VIDEO, "No fast enough alt setting "
1037 "for requested bandwidth.\n");
1041 uvc_trace(UVC_TRACE_VIDEO, "Selecting alternate setting %u "
1042 "(%u B/frame bandwidth).\n", altsetting, best_psize);
1044 ret = usb_set_interface(stream->dev->udev, intfnum, altsetting);
1048 ret = uvc_init_video_isoc(stream, best_ep, gfp_flags);
1050 /* Bulk endpoint, proceed to URB initialization. */
1051 ep = uvc_find_endpoint(&intf->altsetting[0],
1052 stream->header.bEndpointAddress);
1056 ret = uvc_init_video_bulk(stream, ep, gfp_flags);
1062 /* Submit the URBs. */
1063 for (i = 0; i < UVC_URBS; ++i) {
1064 ret = usb_submit_urb(stream->urb[i], gfp_flags);
1066 uvc_printk(KERN_ERR, "Failed to submit URB %u "
1068 uvc_uninit_video(stream, 1);
1076 /* --------------------------------------------------------------------------
1081 * Stop streaming without disabling the video queue.
1083 * To let userspace applications resume without trouble, we must not touch the
1084 * video buffers in any way. We mark the device as frozen to make sure the URB
1085 * completion handler won't try to cancel the queue when we kill the URBs.
1087 int uvc_video_suspend(struct uvc_streaming *stream)
1089 if (!uvc_queue_streaming(&stream->queue))
1093 uvc_uninit_video(stream, 0);
1094 usb_set_interface(stream->dev->udev, stream->intfnum, 0);
1099 * Reconfigure the video interface and restart streaming if it was enabled
1102 * If an error occurs, disable the video queue. This will wake all pending
1103 * buffers, making sure userspace applications are notified of the problem
1104 * instead of waiting forever.
1106 int uvc_video_resume(struct uvc_streaming *stream)
1112 ret = uvc_commit_video(stream, &stream->ctrl);
1114 uvc_queue_enable(&stream->queue, 0);
1118 if (!uvc_queue_streaming(&stream->queue))
1121 ret = uvc_init_video(stream, GFP_NOIO);
1123 uvc_queue_enable(&stream->queue, 0);
1128 /* ------------------------------------------------------------------------
1133 * Initialize the UVC video device by switching to alternate setting 0 and
1134 * retrieve the default format.
1136 * Some cameras (namely the Fuji Finepix) set the format and frame
1137 * indexes to zero. The UVC standard doesn't clearly make this a spec
1138 * violation, so try to silently fix the values if possible.
1140 * This function is called before registering the device with V4L.
1142 int uvc_video_init(struct uvc_streaming *stream)
1144 struct uvc_streaming_control *probe = &stream->ctrl;
1145 struct uvc_format *format = NULL;
1146 struct uvc_frame *frame = NULL;
1150 if (stream->nformats == 0) {
1151 uvc_printk(KERN_INFO, "No supported video formats found.\n");
1155 atomic_set(&stream->active, 0);
1157 /* Initialize the video buffers queue. */
1158 uvc_queue_init(&stream->queue, stream->type, !uvc_no_drop_param);
1160 /* Alternate setting 0 should be the default, yet the XBox Live Vision
1161 * Cam (and possibly other devices) crash or otherwise misbehave if
1162 * they don't receive a SET_INTERFACE request before any other video
1165 usb_set_interface(stream->dev->udev, stream->intfnum, 0);
1167 /* Set the streaming probe control with default streaming parameters
1168 * retrieved from the device. Webcams that don't suport GET_DEF
1169 * requests on the probe control will just keep their current streaming
1172 if (uvc_get_video_ctrl(stream, probe, 1, UVC_GET_DEF) == 0)
1173 uvc_set_video_ctrl(stream, probe, 1);
1175 /* Initialize the streaming parameters with the probe control current
1176 * value. This makes sure SET_CUR requests on the streaming commit
1177 * control will always use values retrieved from a successful GET_CUR
1178 * request on the probe control, as required by the UVC specification.
1180 ret = uvc_get_video_ctrl(stream, probe, 1, UVC_GET_CUR);
1184 /* Check if the default format descriptor exists. Use the first
1185 * available format otherwise.
1187 for (i = stream->nformats; i > 0; --i) {
1188 format = &stream->format[i-1];
1189 if (format->index == probe->bFormatIndex)
1193 if (format->nframes == 0) {
1194 uvc_printk(KERN_INFO, "No frame descriptor found for the "
1195 "default format.\n");
1199 /* Zero bFrameIndex might be correct. Stream-based formats (including
1200 * MPEG-2 TS and DV) do not support frames but have a dummy frame
1201 * descriptor with bFrameIndex set to zero. If the default frame
1202 * descriptor is not found, use the first available frame.
1204 for (i = format->nframes; i > 0; --i) {
1205 frame = &format->frame[i-1];
1206 if (frame->bFrameIndex == probe->bFrameIndex)
1210 probe->bFormatIndex = format->index;
1211 probe->bFrameIndex = frame->bFrameIndex;
1213 stream->cur_format = format;
1214 stream->cur_frame = frame;
1216 /* Select the video decoding function */
1217 if (stream->type == V4L2_BUF_TYPE_VIDEO_CAPTURE) {
1218 if (stream->dev->quirks & UVC_QUIRK_BUILTIN_ISIGHT)
1219 stream->decode = uvc_video_decode_isight;
1220 else if (stream->intf->num_altsetting > 1)
1221 stream->decode = uvc_video_decode_isoc;
1223 stream->decode = uvc_video_decode_bulk;
1225 if (stream->intf->num_altsetting == 1)
1226 stream->decode = uvc_video_encode_bulk;
1228 uvc_printk(KERN_INFO, "Isochronous endpoints are not "
1229 "supported for video output devices.\n");
1238 * Enable or disable the video stream.
1240 int uvc_video_enable(struct uvc_streaming *stream, int enable)
1245 uvc_uninit_video(stream, 1);
1246 usb_set_interface(stream->dev->udev, stream->intfnum, 0);
1247 uvc_queue_enable(&stream->queue, 0);
1251 ret = uvc_queue_enable(&stream->queue, 1);
1255 /* Commit the streaming parameters. */
1256 ret = uvc_commit_video(stream, &stream->ctrl);
1260 return uvc_init_video(stream, GFP_KERNEL);