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/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 int uvc_query_ctrl(struct uvc_device *dev, __u8 query, __u8 unit,
49 __u8 intfnum, __u8 cs, void *data, __u16 size)
53 ret = __uvc_query_ctrl(dev, query, unit, intfnum, cs, data, size,
54 UVC_CTRL_CONTROL_TIMEOUT);
56 uvc_printk(KERN_ERR, "Failed to query (%u) UVC control %u "
57 "(unit %u) : %d (exp. %u).\n", query, cs, unit, ret,
65 static void uvc_fixup_video_ctrl(struct uvc_streaming *stream,
66 struct uvc_streaming_control *ctrl)
68 struct uvc_format *format;
69 struct uvc_frame *frame = NULL;
72 if (ctrl->bFormatIndex <= 0 ||
73 ctrl->bFormatIndex > stream->nformats)
76 format = &stream->format[ctrl->bFormatIndex - 1];
78 for (i = 0; i < format->nframes; ++i) {
79 if (format->frame[i].bFrameIndex == ctrl->bFrameIndex) {
80 frame = &format->frame[i];
88 if (!(format->flags & UVC_FMT_FLAG_COMPRESSED) ||
89 (ctrl->dwMaxVideoFrameSize == 0 &&
90 stream->dev->uvc_version < 0x0110))
91 ctrl->dwMaxVideoFrameSize =
92 frame->dwMaxVideoFrameBufferSize;
94 if (!(format->flags & UVC_FMT_FLAG_COMPRESSED) &&
95 stream->dev->quirks & UVC_QUIRK_FIX_BANDWIDTH &&
96 stream->intf->num_altsetting > 1) {
100 interval = (ctrl->dwFrameInterval > 100000)
101 ? ctrl->dwFrameInterval
102 : frame->dwFrameInterval[0];
104 /* Compute a bandwidth estimation by multiplying the frame
105 * size by the number of video frames per second, divide the
106 * result by the number of USB frames (or micro-frames for
107 * high-speed devices) per second and add the UVC header size
108 * (assumed to be 12 bytes long).
110 bandwidth = frame->wWidth * frame->wHeight / 8 * format->bpp;
111 bandwidth *= 10000000 / interval + 1;
113 if (stream->dev->udev->speed == USB_SPEED_HIGH)
117 ctrl->dwMaxPayloadTransferSize = bandwidth;
121 static int uvc_get_video_ctrl(struct uvc_streaming *stream,
122 struct uvc_streaming_control *ctrl, int probe, __u8 query)
128 size = stream->dev->uvc_version >= 0x0110 ? 34 : 26;
129 if ((stream->dev->quirks & UVC_QUIRK_PROBE_DEF) &&
130 query == UVC_GET_DEF)
133 data = kmalloc(size, GFP_KERNEL);
137 ret = __uvc_query_ctrl(stream->dev, query, 0, stream->intfnum,
138 probe ? UVC_VS_PROBE_CONTROL : UVC_VS_COMMIT_CONTROL, data,
139 size, uvc_timeout_param);
141 if ((query == UVC_GET_MIN || query == UVC_GET_MAX) && ret == 2) {
142 /* Some cameras, mostly based on Bison Electronics chipsets,
143 * answer a GET_MIN or GET_MAX request with the wCompQuality
146 uvc_warn_once(stream->dev, UVC_WARN_MINMAX, "UVC non "
147 "compliance - GET_MIN/MAX(PROBE) incorrectly "
148 "supported. Enabling workaround.\n");
149 memset(ctrl, 0, sizeof *ctrl);
150 ctrl->wCompQuality = le16_to_cpup((__le16 *)data);
153 } else if (query == UVC_GET_DEF && probe == 1 && ret != size) {
154 /* Many cameras don't support the GET_DEF request on their
155 * video probe control. Warn once and return, the caller will
156 * fall back to GET_CUR.
158 uvc_warn_once(stream->dev, UVC_WARN_PROBE_DEF, "UVC non "
159 "compliance - GET_DEF(PROBE) not supported. "
160 "Enabling workaround.\n");
163 } else if (ret != size) {
164 uvc_printk(KERN_ERR, "Failed to query (%u) UVC %s control : "
165 "%d (exp. %u).\n", query, probe ? "probe" : "commit",
171 ctrl->bmHint = le16_to_cpup((__le16 *)&data[0]);
172 ctrl->bFormatIndex = data[2];
173 ctrl->bFrameIndex = data[3];
174 ctrl->dwFrameInterval = le32_to_cpup((__le32 *)&data[4]);
175 ctrl->wKeyFrameRate = le16_to_cpup((__le16 *)&data[8]);
176 ctrl->wPFrameRate = le16_to_cpup((__le16 *)&data[10]);
177 ctrl->wCompQuality = le16_to_cpup((__le16 *)&data[12]);
178 ctrl->wCompWindowSize = le16_to_cpup((__le16 *)&data[14]);
179 ctrl->wDelay = le16_to_cpup((__le16 *)&data[16]);
180 ctrl->dwMaxVideoFrameSize = get_unaligned_le32(&data[18]);
181 ctrl->dwMaxPayloadTransferSize = get_unaligned_le32(&data[22]);
184 ctrl->dwClockFrequency = get_unaligned_le32(&data[26]);
185 ctrl->bmFramingInfo = data[30];
186 ctrl->bPreferedVersion = data[31];
187 ctrl->bMinVersion = data[32];
188 ctrl->bMaxVersion = data[33];
190 ctrl->dwClockFrequency = stream->dev->clock_frequency;
191 ctrl->bmFramingInfo = 0;
192 ctrl->bPreferedVersion = 0;
193 ctrl->bMinVersion = 0;
194 ctrl->bMaxVersion = 0;
197 /* Some broken devices return null or wrong dwMaxVideoFrameSize and
198 * dwMaxPayloadTransferSize fields. Try to get the value from the
199 * format and frame descriptors.
201 uvc_fixup_video_ctrl(stream, ctrl);
209 static int uvc_set_video_ctrl(struct uvc_streaming *stream,
210 struct uvc_streaming_control *ctrl, int probe)
216 size = stream->dev->uvc_version >= 0x0110 ? 34 : 26;
217 data = kzalloc(size, GFP_KERNEL);
221 *(__le16 *)&data[0] = cpu_to_le16(ctrl->bmHint);
222 data[2] = ctrl->bFormatIndex;
223 data[3] = ctrl->bFrameIndex;
224 *(__le32 *)&data[4] = cpu_to_le32(ctrl->dwFrameInterval);
225 *(__le16 *)&data[8] = cpu_to_le16(ctrl->wKeyFrameRate);
226 *(__le16 *)&data[10] = cpu_to_le16(ctrl->wPFrameRate);
227 *(__le16 *)&data[12] = cpu_to_le16(ctrl->wCompQuality);
228 *(__le16 *)&data[14] = cpu_to_le16(ctrl->wCompWindowSize);
229 *(__le16 *)&data[16] = cpu_to_le16(ctrl->wDelay);
230 put_unaligned_le32(ctrl->dwMaxVideoFrameSize, &data[18]);
231 put_unaligned_le32(ctrl->dwMaxPayloadTransferSize, &data[22]);
234 put_unaligned_le32(ctrl->dwClockFrequency, &data[26]);
235 data[30] = ctrl->bmFramingInfo;
236 data[31] = ctrl->bPreferedVersion;
237 data[32] = ctrl->bMinVersion;
238 data[33] = ctrl->bMaxVersion;
241 ret = __uvc_query_ctrl(stream->dev, UVC_SET_CUR, 0, stream->intfnum,
242 probe ? UVC_VS_PROBE_CONTROL : UVC_VS_COMMIT_CONTROL, data,
243 size, uvc_timeout_param);
245 uvc_printk(KERN_ERR, "Failed to set UVC %s control : "
246 "%d (exp. %u).\n", probe ? "probe" : "commit",
255 int uvc_probe_video(struct uvc_streaming *stream,
256 struct uvc_streaming_control *probe)
258 struct uvc_streaming_control probe_min, probe_max;
263 mutex_lock(&stream->mutex);
265 /* Perform probing. The device should adjust the requested values
266 * according to its capabilities. However, some devices, namely the
267 * first generation UVC Logitech webcams, don't implement the Video
268 * Probe control properly, and just return the needed bandwidth. For
269 * that reason, if the needed bandwidth exceeds the maximum available
270 * bandwidth, try to lower the quality.
272 ret = uvc_set_video_ctrl(stream, probe, 1);
276 /* Get the minimum and maximum values for compression settings. */
277 if (!(stream->dev->quirks & UVC_QUIRK_PROBE_MINMAX)) {
278 ret = uvc_get_video_ctrl(stream, &probe_min, 1, UVC_GET_MIN);
281 ret = uvc_get_video_ctrl(stream, &probe_max, 1, UVC_GET_MAX);
285 probe->wCompQuality = probe_max.wCompQuality;
288 for (i = 0; i < 2; ++i) {
289 ret = uvc_set_video_ctrl(stream, probe, 1);
292 ret = uvc_get_video_ctrl(stream, probe, 1, UVC_GET_CUR);
296 if (stream->intf->num_altsetting == 1)
299 bandwidth = probe->dwMaxPayloadTransferSize;
300 if (bandwidth <= stream->maxpsize)
303 if (stream->dev->quirks & UVC_QUIRK_PROBE_MINMAX) {
308 /* TODO: negotiate compression parameters */
309 probe->wKeyFrameRate = probe_min.wKeyFrameRate;
310 probe->wPFrameRate = probe_min.wPFrameRate;
311 probe->wCompQuality = probe_max.wCompQuality;
312 probe->wCompWindowSize = probe_min.wCompWindowSize;
316 mutex_unlock(&stream->mutex);
320 int uvc_commit_video(struct uvc_streaming *stream,
321 struct uvc_streaming_control *probe)
323 return uvc_set_video_ctrl(stream, probe, 0);
326 /* ------------------------------------------------------------------------
330 /* Values for bmHeaderInfo (Video and Still Image Payload Headers, 2.4.3.3) */
331 #define UVC_STREAM_EOH (1 << 7)
332 #define UVC_STREAM_ERR (1 << 6)
333 #define UVC_STREAM_STI (1 << 5)
334 #define UVC_STREAM_RES (1 << 4)
335 #define UVC_STREAM_SCR (1 << 3)
336 #define UVC_STREAM_PTS (1 << 2)
337 #define UVC_STREAM_EOF (1 << 1)
338 #define UVC_STREAM_FID (1 << 0)
340 /* Video payload decoding is handled by uvc_video_decode_start(),
341 * uvc_video_decode_data() and uvc_video_decode_end().
343 * uvc_video_decode_start is called with URB data at the start of a bulk or
344 * isochronous payload. It processes header data and returns the header size
345 * in bytes if successful. If an error occurs, it returns a negative error
346 * code. The following error codes have special meanings.
348 * - EAGAIN informs the caller that the current video buffer should be marked
349 * as done, and that the function should be called again with the same data
350 * and a new video buffer. This is used when end of frame conditions can be
351 * reliably detected at the beginning of the next frame only.
353 * If an error other than -EAGAIN is returned, the caller will drop the current
354 * payload. No call to uvc_video_decode_data and uvc_video_decode_end will be
355 * made until the next payload. -ENODATA can be used to drop the current
356 * payload if no other error code is appropriate.
358 * uvc_video_decode_data is called for every URB with URB data. It copies the
359 * data to the video buffer.
361 * uvc_video_decode_end is called with header data at the end of a bulk or
362 * isochronous payload. It performs any additional header data processing and
363 * returns 0 or a negative error code if an error occured. As header data have
364 * already been processed by uvc_video_decode_start, this functions isn't
365 * required to perform sanity checks a second time.
367 * For isochronous transfers where a payload is always transfered in a single
368 * URB, the three functions will be called in a row.
370 * To let the decoder process header data and update its internal state even
371 * when no video buffer is available, uvc_video_decode_start must be prepared
372 * to be called with a NULL buf parameter. uvc_video_decode_data and
373 * uvc_video_decode_end will never be called with a NULL buffer.
375 static int uvc_video_decode_start(struct uvc_streaming *stream,
376 struct uvc_buffer *buf, const __u8 *data, int len)
381 * - packet must be at least 2 bytes long
382 * - bHeaderLength value must be at least 2 bytes (see above)
383 * - bHeaderLength value can't be larger than the packet size.
385 if (len < 2 || data[0] < 2 || data[0] > len)
388 /* Skip payloads marked with the error bit ("error frames"). */
389 if (data[1] & UVC_STREAM_ERR) {
390 uvc_trace(UVC_TRACE_FRAME, "Dropping payload (error bit "
395 fid = data[1] & UVC_STREAM_FID;
397 /* Store the payload FID bit and return immediately when the buffer is
401 stream->last_fid = fid;
405 /* Synchronize to the input stream by waiting for the FID bit to be
406 * toggled when the the buffer state is not UVC_BUF_STATE_ACTIVE.
407 * stream->last_fid is initialized to -1, so the first isochronous
408 * frame will always be in sync.
410 * If the device doesn't toggle the FID bit, invert stream->last_fid
411 * when the EOF bit is set to force synchronisation on the next packet.
413 if (buf->state != UVC_BUF_STATE_ACTIVE) {
416 if (fid == stream->last_fid) {
417 uvc_trace(UVC_TRACE_FRAME, "Dropping payload (out of "
419 if ((stream->dev->quirks & UVC_QUIRK_STREAM_NO_FID) &&
420 (data[1] & UVC_STREAM_EOF))
421 stream->last_fid ^= UVC_STREAM_FID;
425 if (uvc_clock_param == CLOCK_MONOTONIC)
428 ktime_get_real_ts(&ts);
430 buf->buf.timestamp.tv_sec = ts.tv_sec;
431 buf->buf.timestamp.tv_usec = ts.tv_nsec / NSEC_PER_USEC;
433 /* TODO: Handle PTS and SCR. */
434 buf->state = UVC_BUF_STATE_ACTIVE;
437 /* Mark the buffer as done if we're at the beginning of a new frame.
438 * End of frame detection is better implemented by checking the EOF
439 * bit (FID bit toggling is delayed by one frame compared to the EOF
440 * bit), but some devices don't set the bit at end of frame (and the
441 * last payload can be lost anyway). We thus must check if the FID has
444 * stream->last_fid is initialized to -1, so the first isochronous
445 * frame will never trigger an end of frame detection.
447 * Empty buffers (bytesused == 0) don't trigger end of frame detection
448 * as it doesn't make sense to return an empty buffer. This also
449 * avoids detecting end of frame conditions at FID toggling if the
450 * previous payload had the EOF bit set.
452 if (fid != stream->last_fid && buf->buf.bytesused != 0) {
453 uvc_trace(UVC_TRACE_FRAME, "Frame complete (FID bit "
455 buf->state = UVC_BUF_STATE_READY;
459 stream->last_fid = fid;
464 static void uvc_video_decode_data(struct uvc_streaming *stream,
465 struct uvc_buffer *buf, const __u8 *data, int len)
467 struct uvc_video_queue *queue = &stream->queue;
468 unsigned int maxlen, nbytes;
474 /* Copy the video data to the buffer. */
475 maxlen = buf->buf.length - buf->buf.bytesused;
476 mem = queue->mem + buf->buf.m.offset + buf->buf.bytesused;
477 nbytes = min((unsigned int)len, maxlen);
478 memcpy(mem, data, nbytes);
479 buf->buf.bytesused += nbytes;
481 /* Complete the current frame if the buffer size was exceeded. */
483 uvc_trace(UVC_TRACE_FRAME, "Frame complete (overflow).\n");
484 buf->state = UVC_BUF_STATE_READY;
488 static void uvc_video_decode_end(struct uvc_streaming *stream,
489 struct uvc_buffer *buf, const __u8 *data, int len)
491 /* Mark the buffer as done if the EOF marker is set. */
492 if (data[1] & UVC_STREAM_EOF && buf->buf.bytesused != 0) {
493 uvc_trace(UVC_TRACE_FRAME, "Frame complete (EOF found).\n");
495 uvc_trace(UVC_TRACE_FRAME, "EOF in empty payload.\n");
496 buf->state = UVC_BUF_STATE_READY;
497 if (stream->dev->quirks & UVC_QUIRK_STREAM_NO_FID)
498 stream->last_fid ^= UVC_STREAM_FID;
502 /* Video payload encoding is handled by uvc_video_encode_header() and
503 * uvc_video_encode_data(). Only bulk transfers are currently supported.
505 * uvc_video_encode_header is called at the start of a payload. It adds header
506 * data to the transfer buffer and returns the header size. As the only known
507 * UVC output device transfers a whole frame in a single payload, the EOF bit
508 * is always set in the header.
510 * uvc_video_encode_data is called for every URB and copies the data from the
511 * video buffer to the transfer buffer.
513 static int uvc_video_encode_header(struct uvc_streaming *stream,
514 struct uvc_buffer *buf, __u8 *data, int len)
516 data[0] = 2; /* Header length */
517 data[1] = UVC_STREAM_EOH | UVC_STREAM_EOF
518 | (stream->last_fid & UVC_STREAM_FID);
522 static int uvc_video_encode_data(struct uvc_streaming *stream,
523 struct uvc_buffer *buf, __u8 *data, int len)
525 struct uvc_video_queue *queue = &stream->queue;
529 /* Copy video data to the URB buffer. */
530 mem = queue->mem + buf->buf.m.offset + queue->buf_used;
531 nbytes = min((unsigned int)len, buf->buf.bytesused - queue->buf_used);
532 nbytes = min(stream->bulk.max_payload_size - stream->bulk.payload_size,
534 memcpy(data, mem, nbytes);
536 queue->buf_used += nbytes;
541 /* ------------------------------------------------------------------------
546 * Completion handler for video URBs.
548 static void uvc_video_decode_isoc(struct urb *urb, struct uvc_streaming *stream,
549 struct uvc_buffer *buf)
554 for (i = 0; i < urb->number_of_packets; ++i) {
555 if (urb->iso_frame_desc[i].status < 0) {
556 uvc_trace(UVC_TRACE_FRAME, "USB isochronous frame "
557 "lost (%d).\n", urb->iso_frame_desc[i].status);
558 /* Mark the buffer as faulty. */
564 /* Decode the payload header. */
565 mem = urb->transfer_buffer + urb->iso_frame_desc[i].offset;
567 ret = uvc_video_decode_start(stream, buf, mem,
568 urb->iso_frame_desc[i].actual_length);
570 buf = uvc_queue_next_buffer(&stream->queue,
572 } while (ret == -EAGAIN);
577 /* Decode the payload data. */
578 uvc_video_decode_data(stream, buf, mem + ret,
579 urb->iso_frame_desc[i].actual_length - ret);
581 /* Process the header again. */
582 uvc_video_decode_end(stream, buf, mem,
583 urb->iso_frame_desc[i].actual_length);
585 if (buf->state == UVC_BUF_STATE_READY) {
586 if (buf->buf.length != buf->buf.bytesused &&
587 !(stream->cur_format->flags &
588 UVC_FMT_FLAG_COMPRESSED))
591 buf = uvc_queue_next_buffer(&stream->queue, buf);
596 static void uvc_video_decode_bulk(struct urb *urb, struct uvc_streaming *stream,
597 struct uvc_buffer *buf)
602 if (urb->actual_length == 0)
605 mem = urb->transfer_buffer;
606 len = urb->actual_length;
607 stream->bulk.payload_size += len;
609 /* If the URB is the first of its payload, decode and save the
612 if (stream->bulk.header_size == 0 && !stream->bulk.skip_payload) {
614 ret = uvc_video_decode_start(stream, buf, mem, len);
616 buf = uvc_queue_next_buffer(&stream->queue,
618 } while (ret == -EAGAIN);
620 /* If an error occured skip the rest of the payload. */
621 if (ret < 0 || buf == NULL) {
622 stream->bulk.skip_payload = 1;
624 memcpy(stream->bulk.header, mem, ret);
625 stream->bulk.header_size = ret;
632 /* The buffer queue might have been cancelled while a bulk transfer
633 * was in progress, so we can reach here with buf equal to NULL. Make
634 * sure buf is never dereferenced if NULL.
637 /* Process video data. */
638 if (!stream->bulk.skip_payload && buf != NULL)
639 uvc_video_decode_data(stream, buf, mem, len);
641 /* Detect the payload end by a URB smaller than the maximum size (or
642 * a payload size equal to the maximum) and process the header again.
644 if (urb->actual_length < urb->transfer_buffer_length ||
645 stream->bulk.payload_size >= stream->bulk.max_payload_size) {
646 if (!stream->bulk.skip_payload && buf != NULL) {
647 uvc_video_decode_end(stream, buf, stream->bulk.header,
648 stream->bulk.payload_size);
649 if (buf->state == UVC_BUF_STATE_READY)
650 buf = uvc_queue_next_buffer(&stream->queue,
654 stream->bulk.header_size = 0;
655 stream->bulk.skip_payload = 0;
656 stream->bulk.payload_size = 0;
660 static void uvc_video_encode_bulk(struct urb *urb, struct uvc_streaming *stream,
661 struct uvc_buffer *buf)
663 u8 *mem = urb->transfer_buffer;
664 int len = stream->urb_size, ret;
667 urb->transfer_buffer_length = 0;
671 /* If the URB is the first of its payload, add the header. */
672 if (stream->bulk.header_size == 0) {
673 ret = uvc_video_encode_header(stream, buf, mem, len);
674 stream->bulk.header_size = ret;
675 stream->bulk.payload_size += ret;
680 /* Process video data. */
681 ret = uvc_video_encode_data(stream, buf, mem, len);
683 stream->bulk.payload_size += ret;
686 if (buf->buf.bytesused == stream->queue.buf_used ||
687 stream->bulk.payload_size == stream->bulk.max_payload_size) {
688 if (buf->buf.bytesused == stream->queue.buf_used) {
689 stream->queue.buf_used = 0;
690 buf->state = UVC_BUF_STATE_READY;
691 uvc_queue_next_buffer(&stream->queue, buf);
692 stream->last_fid ^= UVC_STREAM_FID;
695 stream->bulk.header_size = 0;
696 stream->bulk.payload_size = 0;
699 urb->transfer_buffer_length = stream->urb_size - len;
702 static void uvc_video_complete(struct urb *urb)
704 struct uvc_streaming *stream = urb->context;
705 struct uvc_video_queue *queue = &stream->queue;
706 struct uvc_buffer *buf = NULL;
710 switch (urb->status) {
715 uvc_printk(KERN_WARNING, "Non-zero status (%d) in video "
716 "completion handler.\n", urb->status);
718 case -ENOENT: /* usb_kill_urb() called. */
722 case -ECONNRESET: /* usb_unlink_urb() called. */
723 case -ESHUTDOWN: /* The endpoint is being disabled. */
724 uvc_queue_cancel(queue, urb->status == -ESHUTDOWN);
728 spin_lock_irqsave(&queue->irqlock, flags);
729 if (!list_empty(&queue->irqqueue))
730 buf = list_first_entry(&queue->irqqueue, struct uvc_buffer,
732 spin_unlock_irqrestore(&queue->irqlock, flags);
734 stream->decode(urb, stream, buf);
736 if ((ret = usb_submit_urb(urb, GFP_ATOMIC)) < 0) {
737 uvc_printk(KERN_ERR, "Failed to resubmit video URB (%d).\n",
743 * Free transfer buffers.
745 static void uvc_free_urb_buffers(struct uvc_streaming *stream)
749 for (i = 0; i < UVC_URBS; ++i) {
750 if (stream->urb_buffer[i]) {
751 usb_free_coherent(stream->dev->udev, stream->urb_size,
752 stream->urb_buffer[i], stream->urb_dma[i]);
753 stream->urb_buffer[i] = NULL;
757 stream->urb_size = 0;
761 * Allocate transfer buffers. This function can be called with buffers
762 * already allocated when resuming from suspend, in which case it will
763 * return without touching the buffers.
765 * Limit the buffer size to UVC_MAX_PACKETS bulk/isochronous packets. If the
766 * system is too low on memory try successively smaller numbers of packets
767 * until allocation succeeds.
769 * Return the number of allocated packets on success or 0 when out of memory.
771 static int uvc_alloc_urb_buffers(struct uvc_streaming *stream,
772 unsigned int size, unsigned int psize, gfp_t gfp_flags)
774 unsigned int npackets;
777 /* Buffers are already allocated, bail out. */
778 if (stream->urb_size)
779 return stream->urb_size / psize;
781 /* Compute the number of packets. Bulk endpoints might transfer UVC
782 * payloads accross multiple URBs.
784 npackets = DIV_ROUND_UP(size, psize);
785 if (npackets > UVC_MAX_PACKETS)
786 npackets = UVC_MAX_PACKETS;
788 /* Retry allocations until one succeed. */
789 for (; npackets > 1; npackets /= 2) {
790 for (i = 0; i < UVC_URBS; ++i) {
791 stream->urb_size = psize * npackets;
792 stream->urb_buffer[i] = usb_alloc_coherent(
793 stream->dev->udev, stream->urb_size,
794 gfp_flags | __GFP_NOWARN, &stream->urb_dma[i]);
795 if (!stream->urb_buffer[i]) {
796 uvc_free_urb_buffers(stream);
802 uvc_trace(UVC_TRACE_VIDEO, "Allocated %u URB buffers "
803 "of %ux%u bytes each.\n", UVC_URBS, npackets,
809 uvc_trace(UVC_TRACE_VIDEO, "Failed to allocate URB buffers (%u bytes "
810 "per packet).\n", psize);
815 * Uninitialize isochronous/bulk URBs and free transfer buffers.
817 static void uvc_uninit_video(struct uvc_streaming *stream, int free_buffers)
822 for (i = 0; i < UVC_URBS; ++i) {
823 urb = stream->urb[i];
829 stream->urb[i] = NULL;
833 uvc_free_urb_buffers(stream);
837 * Initialize isochronous URBs and allocate transfer buffers. The packet size
838 * is given by the endpoint.
840 static int uvc_init_video_isoc(struct uvc_streaming *stream,
841 struct usb_host_endpoint *ep, gfp_t gfp_flags)
844 unsigned int npackets, i, j;
848 psize = le16_to_cpu(ep->desc.wMaxPacketSize);
849 psize = (psize & 0x07ff) * (1 + ((psize >> 11) & 3));
850 size = stream->ctrl.dwMaxVideoFrameSize;
852 npackets = uvc_alloc_urb_buffers(stream, size, psize, gfp_flags);
856 size = npackets * psize;
858 for (i = 0; i < UVC_URBS; ++i) {
859 urb = usb_alloc_urb(npackets, gfp_flags);
861 uvc_uninit_video(stream, 1);
865 urb->dev = stream->dev->udev;
866 urb->context = stream;
867 urb->pipe = usb_rcvisocpipe(stream->dev->udev,
868 ep->desc.bEndpointAddress);
869 urb->transfer_flags = URB_ISO_ASAP | URB_NO_TRANSFER_DMA_MAP;
870 urb->interval = ep->desc.bInterval;
871 urb->transfer_buffer = stream->urb_buffer[i];
872 urb->transfer_dma = stream->urb_dma[i];
873 urb->complete = uvc_video_complete;
874 urb->number_of_packets = npackets;
875 urb->transfer_buffer_length = size;
877 for (j = 0; j < npackets; ++j) {
878 urb->iso_frame_desc[j].offset = j * psize;
879 urb->iso_frame_desc[j].length = psize;
882 stream->urb[i] = urb;
889 * Initialize bulk URBs and allocate transfer buffers. The packet size is
890 * given by the endpoint.
892 static int uvc_init_video_bulk(struct uvc_streaming *stream,
893 struct usb_host_endpoint *ep, gfp_t gfp_flags)
896 unsigned int npackets, pipe, i;
900 psize = le16_to_cpu(ep->desc.wMaxPacketSize) & 0x07ff;
901 size = stream->ctrl.dwMaxPayloadTransferSize;
902 stream->bulk.max_payload_size = size;
904 npackets = uvc_alloc_urb_buffers(stream, size, psize, gfp_flags);
908 size = npackets * psize;
910 if (usb_endpoint_dir_in(&ep->desc))
911 pipe = usb_rcvbulkpipe(stream->dev->udev,
912 ep->desc.bEndpointAddress);
914 pipe = usb_sndbulkpipe(stream->dev->udev,
915 ep->desc.bEndpointAddress);
917 if (stream->type == V4L2_BUF_TYPE_VIDEO_OUTPUT)
920 for (i = 0; i < UVC_URBS; ++i) {
921 urb = usb_alloc_urb(0, gfp_flags);
923 uvc_uninit_video(stream, 1);
927 usb_fill_bulk_urb(urb, stream->dev->udev, pipe,
928 stream->urb_buffer[i], size, uvc_video_complete,
930 urb->transfer_flags = URB_NO_TRANSFER_DMA_MAP;
931 urb->transfer_dma = stream->urb_dma[i];
933 stream->urb[i] = urb;
940 * Initialize isochronous/bulk URBs and allocate transfer buffers.
942 static int uvc_init_video(struct uvc_streaming *stream, gfp_t gfp_flags)
944 struct usb_interface *intf = stream->intf;
945 struct usb_host_endpoint *ep;
949 stream->last_fid = -1;
950 stream->bulk.header_size = 0;
951 stream->bulk.skip_payload = 0;
952 stream->bulk.payload_size = 0;
954 if (intf->num_altsetting > 1) {
955 struct usb_host_endpoint *best_ep = NULL;
956 unsigned int best_psize = 3 * 1024;
957 unsigned int bandwidth;
958 unsigned int uninitialized_var(altsetting);
959 int intfnum = stream->intfnum;
961 /* Isochronous endpoint, select the alternate setting. */
962 bandwidth = stream->ctrl.dwMaxPayloadTransferSize;
964 if (bandwidth == 0) {
965 uvc_trace(UVC_TRACE_VIDEO, "Device requested null "
966 "bandwidth, defaulting to lowest.\n");
969 uvc_trace(UVC_TRACE_VIDEO, "Device requested %u "
970 "B/frame bandwidth.\n", bandwidth);
973 for (i = 0; i < intf->num_altsetting; ++i) {
974 struct usb_host_interface *alts;
977 alts = &intf->altsetting[i];
978 ep = uvc_find_endpoint(alts,
979 stream->header.bEndpointAddress);
983 /* Check if the bandwidth is high enough. */
984 psize = le16_to_cpu(ep->desc.wMaxPacketSize);
985 psize = (psize & 0x07ff) * (1 + ((psize >> 11) & 3));
986 if (psize >= bandwidth && psize <= best_psize) {
993 if (best_ep == NULL) {
994 uvc_trace(UVC_TRACE_VIDEO, "No fast enough alt setting "
995 "for requested bandwidth.\n");
999 uvc_trace(UVC_TRACE_VIDEO, "Selecting alternate setting %u "
1000 "(%u B/frame bandwidth).\n", altsetting, best_psize);
1002 ret = usb_set_interface(stream->dev->udev, intfnum, altsetting);
1006 ret = uvc_init_video_isoc(stream, best_ep, gfp_flags);
1008 /* Bulk endpoint, proceed to URB initialization. */
1009 ep = uvc_find_endpoint(&intf->altsetting[0],
1010 stream->header.bEndpointAddress);
1014 ret = uvc_init_video_bulk(stream, ep, gfp_flags);
1020 /* Submit the URBs. */
1021 for (i = 0; i < UVC_URBS; ++i) {
1022 ret = usb_submit_urb(stream->urb[i], gfp_flags);
1024 uvc_printk(KERN_ERR, "Failed to submit URB %u "
1026 uvc_uninit_video(stream, 1);
1034 /* --------------------------------------------------------------------------
1039 * Stop streaming without disabling the video queue.
1041 * To let userspace applications resume without trouble, we must not touch the
1042 * video buffers in any way. We mark the device as frozen to make sure the URB
1043 * completion handler won't try to cancel the queue when we kill the URBs.
1045 int uvc_video_suspend(struct uvc_streaming *stream)
1047 if (!uvc_queue_streaming(&stream->queue))
1051 uvc_uninit_video(stream, 0);
1052 usb_set_interface(stream->dev->udev, stream->intfnum, 0);
1057 * Reconfigure the video interface and restart streaming if it was enabled
1060 * If an error occurs, disable the video queue. This will wake all pending
1061 * buffers, making sure userspace applications are notified of the problem
1062 * instead of waiting forever.
1064 int uvc_video_resume(struct uvc_streaming *stream)
1070 ret = uvc_commit_video(stream, &stream->ctrl);
1072 uvc_queue_enable(&stream->queue, 0);
1076 if (!uvc_queue_streaming(&stream->queue))
1079 ret = uvc_init_video(stream, GFP_NOIO);
1081 uvc_queue_enable(&stream->queue, 0);
1086 /* ------------------------------------------------------------------------
1091 * Initialize the UVC video device by switching to alternate setting 0 and
1092 * retrieve the default format.
1094 * Some cameras (namely the Fuji Finepix) set the format and frame
1095 * indexes to zero. The UVC standard doesn't clearly make this a spec
1096 * violation, so try to silently fix the values if possible.
1098 * This function is called before registering the device with V4L.
1100 int uvc_video_init(struct uvc_streaming *stream)
1102 struct uvc_streaming_control *probe = &stream->ctrl;
1103 struct uvc_format *format = NULL;
1104 struct uvc_frame *frame = NULL;
1108 if (stream->nformats == 0) {
1109 uvc_printk(KERN_INFO, "No supported video formats found.\n");
1113 atomic_set(&stream->active, 0);
1115 /* Initialize the video buffers queue. */
1116 uvc_queue_init(&stream->queue, stream->type, !uvc_no_drop_param);
1118 /* Alternate setting 0 should be the default, yet the XBox Live Vision
1119 * Cam (and possibly other devices) crash or otherwise misbehave if
1120 * they don't receive a SET_INTERFACE request before any other video
1123 usb_set_interface(stream->dev->udev, stream->intfnum, 0);
1125 /* Set the streaming probe control with default streaming parameters
1126 * retrieved from the device. Webcams that don't suport GET_DEF
1127 * requests on the probe control will just keep their current streaming
1130 if (uvc_get_video_ctrl(stream, probe, 1, UVC_GET_DEF) == 0)
1131 uvc_set_video_ctrl(stream, probe, 1);
1133 /* Initialize the streaming parameters with the probe control current
1134 * value. This makes sure SET_CUR requests on the streaming commit
1135 * control will always use values retrieved from a successful GET_CUR
1136 * request on the probe control, as required by the UVC specification.
1138 ret = uvc_get_video_ctrl(stream, probe, 1, UVC_GET_CUR);
1142 /* Check if the default format descriptor exists. Use the first
1143 * available format otherwise.
1145 for (i = stream->nformats; i > 0; --i) {
1146 format = &stream->format[i-1];
1147 if (format->index == probe->bFormatIndex)
1151 if (format->nframes == 0) {
1152 uvc_printk(KERN_INFO, "No frame descriptor found for the "
1153 "default format.\n");
1157 /* Zero bFrameIndex might be correct. Stream-based formats (including
1158 * MPEG-2 TS and DV) do not support frames but have a dummy frame
1159 * descriptor with bFrameIndex set to zero. If the default frame
1160 * descriptor is not found, use the first available frame.
1162 for (i = format->nframes; i > 0; --i) {
1163 frame = &format->frame[i-1];
1164 if (frame->bFrameIndex == probe->bFrameIndex)
1168 probe->bFormatIndex = format->index;
1169 probe->bFrameIndex = frame->bFrameIndex;
1171 stream->cur_format = format;
1172 stream->cur_frame = frame;
1174 /* Select the video decoding function */
1175 if (stream->type == V4L2_BUF_TYPE_VIDEO_CAPTURE) {
1176 if (stream->dev->quirks & UVC_QUIRK_BUILTIN_ISIGHT)
1177 stream->decode = uvc_video_decode_isight;
1178 else if (stream->intf->num_altsetting > 1)
1179 stream->decode = uvc_video_decode_isoc;
1181 stream->decode = uvc_video_decode_bulk;
1183 if (stream->intf->num_altsetting == 1)
1184 stream->decode = uvc_video_encode_bulk;
1186 uvc_printk(KERN_INFO, "Isochronous endpoints are not "
1187 "supported for video output devices.\n");
1196 * Enable or disable the video stream.
1198 int uvc_video_enable(struct uvc_streaming *stream, int enable)
1203 uvc_uninit_video(stream, 1);
1204 usb_set_interface(stream->dev->udev, stream->intfnum, 0);
1205 uvc_queue_enable(&stream->queue, 0);
1209 ret = uvc_queue_enable(&stream->queue, 1);
1213 /* Commit the streaming parameters. */
1214 ret = uvc_commit_video(stream, &stream->ctrl);
1218 return uvc_init_video(stream, GFP_KERNEL);