Merge branch 'linus' into core/rcu

Conflicts:

	include/linux/rculist.h
	kernel/rcupreempt.c

Signed-off-by: Ingo Molnar <mingo@elte.hu>

1 files changed, 1955 insertions, 0 deletions

diff --git a/drivers/media/video/uvc/uvc_driver.c b/drivers/media/video/uvc/uvc_driver.c
new file mode 100644
index 00000000000..60ced589f89
--- /dev/null
+++ b/drivers/media/video/uvc/uvc_driver.c
@@ -0,0 +1,1955 @@
+/*
+ *      uvc_driver.c  --  USB Video Class driver
+ *
+ *      Copyright (C) 2005-2008
+ *          Laurent Pinchart (laurent.pinchart@skynet.be)
+ *
+ *      This program is free software; you can redistribute it and/or modify
+ *      it under the terms of the GNU General Public License as published by
+ *      the Free Software Foundation; either version 2 of the License, or
+ *      (at your option) any later version.
+ *
+ */
+
+/*
+ * This driver aims to support video input devices compliant with the 'USB
+ * Video Class' specification.
+ *
+ * The driver doesn't support the deprecated v4l1 interface. It implements the
+ * mmap capture method only, and doesn't do any image format conversion in
+ * software. If your user-space application doesn't support YUYV or MJPEG, fix
+ * it :-). Please note that the MJPEG data have been stripped from their
+ * Huffman tables (DHT marker), you will need to add it back if your JPEG
+ * codec can't handle MJPEG data.
+ */
+
+#include <linux/kernel.h>
+#include <linux/version.h>
+#include <linux/list.h>
+#include <linux/module.h>
+#include <linux/usb.h>
+#include <linux/videodev2.h>
+#include <linux/vmalloc.h>
+#include <linux/wait.h>
+#include <asm/atomic.h>
+
+#include <media/v4l2-common.h>
+
+#include "uvcvideo.h"
+
+#define DRIVER_AUTHOR		"Laurent Pinchart <laurent.pinchart@skynet.be>"
+#define DRIVER_DESC		"USB Video Class driver"
+#ifndef DRIVER_VERSION
+#define DRIVER_VERSION		"v0.1.0"
+#endif
+
+static unsigned int uvc_quirks_param;
+unsigned int uvc_trace_param;
+
+/* ------------------------------------------------------------------------
+ * Control, formats, ...
+ */
+
+static struct uvc_format_desc uvc_fmts[] = {
+	{
+		.name		= "YUV 4:2:2 (YUYV)",
+		.guid		= UVC_GUID_FORMAT_YUY2,
+		.fcc		= V4L2_PIX_FMT_YUYV,
+	},
+	{
+		.name		= "YUV 4:2:0 (NV12)",
+		.guid		= UVC_GUID_FORMAT_NV12,
+		.fcc		= V4L2_PIX_FMT_NV12,
+	},
+	{
+		.name		= "MJPEG",
+		.guid		= UVC_GUID_FORMAT_MJPEG,
+		.fcc		= V4L2_PIX_FMT_MJPEG,
+	},
+	{
+		.name		= "YVU 4:2:0 (YV12)",
+		.guid		= UVC_GUID_FORMAT_YV12,
+		.fcc		= V4L2_PIX_FMT_YVU420,
+	},
+	{
+		.name		= "YUV 4:2:0 (I420)",
+		.guid		= UVC_GUID_FORMAT_I420,
+		.fcc		= V4L2_PIX_FMT_YUV420,
+	},
+	{
+		.name		= "YUV 4:2:2 (UYVY)",
+		.guid		= UVC_GUID_FORMAT_UYVY,
+		.fcc		= V4L2_PIX_FMT_UYVY,
+	},
+	{
+		.name		= "Greyscale",
+		.guid		= UVC_GUID_FORMAT_Y800,
+		.fcc		= V4L2_PIX_FMT_GREY,
+	},
+	{
+		.name		= "RGB Bayer",
+		.guid		= UVC_GUID_FORMAT_BY8,
+		.fcc		= V4L2_PIX_FMT_SBGGR8,
+	},
+};
+
+/* ------------------------------------------------------------------------
+ * Utility functions
+ */
+
+struct usb_host_endpoint *uvc_find_endpoint(struct usb_host_interface *alts,
+		__u8 epaddr)
+{
+	struct usb_host_endpoint *ep;
+	unsigned int i;
+
+	for (i = 0; i < alts->desc.bNumEndpoints; ++i) {
+		ep = &alts->endpoint[i];
+		if (ep->desc.bEndpointAddress == epaddr)
+			return ep;
+	}
+
+	return NULL;
+}
+
+static struct uvc_format_desc *uvc_format_by_guid(const __u8 guid[16])
+{
+	unsigned int len = ARRAY_SIZE(uvc_fmts);
+	unsigned int i;
+
+	for (i = 0; i < len; ++i) {
+		if (memcmp(guid, uvc_fmts[i].guid, 16) == 0)
+			return &uvc_fmts[i];
+	}
+
+	return NULL;
+}
+
+static __u32 uvc_colorspace(const __u8 primaries)
+{
+	static const __u8 colorprimaries[] = {
+		0,
+		V4L2_COLORSPACE_SRGB,
+		V4L2_COLORSPACE_470_SYSTEM_M,
+		V4L2_COLORSPACE_470_SYSTEM_BG,
+		V4L2_COLORSPACE_SMPTE170M,
+		V4L2_COLORSPACE_SMPTE240M,
+	};
+
+	if (primaries < ARRAY_SIZE(colorprimaries))
+		return colorprimaries[primaries];
+
+	return 0;
+}
+
+/* Simplify a fraction using a simple continued fraction decomposition. The
+ * idea here is to convert fractions such as 333333/10000000 to 1/30 using
+ * 32 bit arithmetic only. The algorithm is not perfect and relies upon two
+ * arbitrary parameters to remove non-significative terms from the simple
+ * continued fraction decomposition. Using 8 and 333 for n_terms and threshold
+ * respectively seems to give nice results.
+ */
+void uvc_simplify_fraction(uint32_t *numerator, uint32_t *denominator,
+		unsigned int n_terms, unsigned int threshold)
+{
+	uint32_t *an;
+	uint32_t x, y, r;
+	unsigned int i, n;
+
+	an = kmalloc(n_terms * sizeof *an, GFP_KERNEL);
+	if (an == NULL)
+		return;
+
+	/* Convert the fraction to a simple continued fraction. See
+	 * http://mathforum.org/dr.math/faq/faq.fractions.html
+	 * Stop if the current term is bigger than or equal to the given
+	 * threshold.
+	 */
+	x = *numerator;
+	y = *denominator;
+
+	for (n = 0; n < n_terms && y != 0; ++n) {
+		an[n] = x / y;
+		if (an[n] >= threshold) {
+			if (n < 2)
+				n++;
+			break;
+		}
+
+		r = x - an[n] * y;
+		x = y;
+		y = r;
+	}
+
+	/* Expand the simple continued fraction back to an integer fraction. */
+	x = 0;
+	y = 1;
+
+	for (i = n; i > 0; --i) {
+		r = y;
+		y = an[i-1] * y + x;
+		x = r;
+	}
+
+	*numerator = y;
+	*denominator = x;
+	kfree(an);
+}
+
+/* Convert a fraction to a frame interval in 100ns multiples. The idea here is
+ * to compute numerator / denominator * 10000000 using 32 bit fixed point
+ * arithmetic only.
+ */
+uint32_t uvc_fraction_to_interval(uint32_t numerator, uint32_t denominator)
+{
+	uint32_t multiplier;
+
+	/* Saturate the result if the operation would overflow. */
+	if (denominator == 0 ||
+	    numerator/denominator >= ((uint32_t)-1)/10000000)
+		return (uint32_t)-1;
+
+	/* Divide both the denominator and the multiplier by two until
+	 * numerator * multiplier doesn't overflow. If anyone knows a better
+	 * algorithm please let me know.
+	 */
+	multiplier = 10000000;
+	while (numerator > ((uint32_t)-1)/multiplier) {
+		multiplier /= 2;
+		denominator /= 2;
+	}
+
+	return denominator ? numerator * multiplier / denominator : 0;
+}
+
+/* ------------------------------------------------------------------------
+ * Terminal and unit management
+ */
+
+static struct uvc_entity *uvc_entity_by_id(struct uvc_device *dev, int id)
+{
+	struct uvc_entity *entity;
+
+	list_for_each_entry(entity, &dev->entities, list) {
+		if (entity->id == id)
+			return entity;
+	}
+
+	return NULL;
+}
+
+static struct uvc_entity *uvc_entity_by_reference(struct uvc_device *dev,
+	int id, struct uvc_entity *entity)
+{
+	unsigned int i;
+
+	if (entity == NULL)
+		entity = list_entry(&dev->entities, struct uvc_entity, list);
+
+	list_for_each_entry_continue(entity, &dev->entities, list) {
+		switch (UVC_ENTITY_TYPE(entity)) {
+		case TT_STREAMING:
+			if (entity->output.bSourceID == id)
+				return entity;
+			break;
+
+		case VC_PROCESSING_UNIT:
+			if (entity->processing.bSourceID == id)
+				return entity;
+			break;
+
+		case VC_SELECTOR_UNIT:
+			for (i = 0; i < entity->selector.bNrInPins; ++i)
+				if (entity->selector.baSourceID[i] == id)
+					return entity;
+			break;
+
+		case VC_EXTENSION_UNIT:
+			for (i = 0; i < entity->extension.bNrInPins; ++i)
+				if (entity->extension.baSourceID[i] == id)
+					return entity;
+			break;
+		}
+	}
+
+	return NULL;
+}
+
+/* ------------------------------------------------------------------------
+ * Descriptors handling
+ */
+
+static int uvc_parse_format(struct uvc_device *dev,
+	struct uvc_streaming *streaming, struct uvc_format *format,
+	__u32 **intervals, unsigned char *buffer, int buflen)
+{
+	struct usb_interface *intf = streaming->intf;
+	struct usb_host_interface *alts = intf->cur_altsetting;
+	struct uvc_format_desc *fmtdesc;
+	struct uvc_frame *frame;
+	const unsigned char *start = buffer;
+	unsigned int interval;
+	unsigned int i, n;
+	__u8 ftype;
+
+	format->type = buffer[2];
+	format->index = buffer[3];
+
+	switch (buffer[2]) {
+	case VS_FORMAT_UNCOMPRESSED:
+	case VS_FORMAT_FRAME_BASED:
+		if (buflen < 27) {
+			uvc_trace(UVC_TRACE_DESCR, "device %d videostreaming"
+			       "interface %d FORMAT error\n",
+			       dev->udev->devnum,
+			       alts->desc.bInterfaceNumber);
+			return -EINVAL;
+		}
+
+		/* Find the format descriptor from its GUID. */
+		fmtdesc = uvc_format_by_guid(&buffer[5]);
+
+		if (fmtdesc != NULL) {
+			strncpy(format->name, fmtdesc->name,
+				sizeof format->name);
+			format->fcc = fmtdesc->fcc;
+		} else {
+			uvc_printk(KERN_INFO, "Unknown video format "
+				UVC_GUID_FORMAT "\n",
+				UVC_GUID_ARGS(&buffer[5]));
+			snprintf(format->name, sizeof format->name,
+				UVC_GUID_FORMAT, UVC_GUID_ARGS(&buffer[5]));
+			format->fcc = 0;
+		}
+
+		format->bpp = buffer[21];
+		if (buffer[2] == VS_FORMAT_UNCOMPRESSED) {
+			ftype = VS_FRAME_UNCOMPRESSED;
+		} else {
+			ftype = VS_FRAME_FRAME_BASED;
+			if (buffer[27])
+				format->flags = UVC_FMT_FLAG_COMPRESSED;
+		}
+		break;
+
+	case VS_FORMAT_MJPEG:
+		if (buflen < 11) {
+			uvc_trace(UVC_TRACE_DESCR, "device %d videostreaming"
+			       "interface %d FORMAT error\n",
+			       dev->udev->devnum,
+			       alts->desc.bInterfaceNumber);
+			return -EINVAL;
+		}
+
+		strncpy(format->name, "MJPEG", sizeof format->name);
+		format->fcc = V4L2_PIX_FMT_MJPEG;
+		format->flags = UVC_FMT_FLAG_COMPRESSED;
+		format->bpp = 0;
+		ftype = VS_FRAME_MJPEG;
+		break;
+
+	case VS_FORMAT_DV:
+		if (buflen < 9) {
+			uvc_trace(UVC_TRACE_DESCR, "device %d videostreaming"
+			       "interface %d FORMAT error\n",
+			       dev->udev->devnum,
+			       alts->desc.bInterfaceNumber);
+			return -EINVAL;
+		}
+
+		switch (buffer[8] & 0x7f) {
+		case 0:
+			strncpy(format->name, "SD-DV", sizeof format->name);
+			break;
+		case 1:
+			strncpy(format->name, "SDL-DV", sizeof format->name);
+			break;
+		case 2:
+			strncpy(format->name, "HD-DV", sizeof format->name);
+			break;
+		default:
+			uvc_trace(UVC_TRACE_DESCR, "device %d videostreaming"
+			       "interface %d: unknown DV format %u\n",
+			       dev->udev->devnum,
+			       alts->desc.bInterfaceNumber, buffer[8]);
+			return -EINVAL;
+		}
+
+		strncat(format->name, buffer[8] & (1 << 7) ? " 60Hz" : " 50Hz",
+			sizeof format->name);
+
+		format->fcc = V4L2_PIX_FMT_DV;
+		format->flags = UVC_FMT_FLAG_COMPRESSED | UVC_FMT_FLAG_STREAM;
+		format->bpp = 0;
+		ftype = 0;
+
+		/* Create a dummy frame descriptor. */
+		frame = &format->frame[0];
+		memset(&format->frame[0], 0, sizeof format->frame[0]);
+		frame->bFrameIntervalType = 1;
+		frame->dwDefaultFrameInterval = 1;
+		frame->dwFrameInterval = *intervals;
+		*(*intervals)++ = 1;
+		format->nframes = 1;
+		break;
+
+	case VS_FORMAT_MPEG2TS:
+	case VS_FORMAT_STREAM_BASED:
+		/* Not supported yet. */
+	default:
+		uvc_trace(UVC_TRACE_DESCR, "device %d videostreaming"
+		       "interface %d unsupported format %u\n",
+		       dev->udev->devnum, alts->desc.bInterfaceNumber,
+		       buffer[2]);
+		return -EINVAL;
+	}
+
+	uvc_trace(UVC_TRACE_DESCR, "Found format %s.\n", format->name);
+
+	buflen -= buffer[0];
+	buffer += buffer[0];
+
+	/* Parse the frame descriptors. Only uncompressed, MJPEG and frame
+	 * based formats have frame descriptors.
+	 */
+	while (buflen > 2 && buffer[2] == ftype) {
+		frame = &format->frame[format->nframes];
+
+		if (ftype != VS_FRAME_FRAME_BASED)
+			n = buflen > 25 ? buffer[25] : 0;
+		else
+			n = buflen > 21 ? buffer[21] : 0;
+
+		n = n ? n : 3;
+
+		if (buflen < 26 + 4*n) {
+			uvc_trace(UVC_TRACE_DESCR, "device %d videostreaming"
+			       "interface %d FRAME error\n", dev->udev->devnum,
+			       alts->desc.bInterfaceNumber);
+			return -EINVAL;
+		}
+
+		frame->bFrameIndex = buffer[3];
+		frame->bmCapabilities = buffer[4];
+		frame->wWidth = le16_to_cpup((__le16 *)&buffer[5]);
+		frame->wHeight = le16_to_cpup((__le16 *)&buffer[7]);
+		frame->dwMinBitRate = le32_to_cpup((__le32 *)&buffer[9]);
+		frame->dwMaxBitRate = le32_to_cpup((__le32 *)&buffer[13]);
+		if (ftype != VS_FRAME_FRAME_BASED) {
+			frame->dwMaxVideoFrameBufferSize =
+				le32_to_cpup((__le32 *)&buffer[17]);
+			frame->dwDefaultFrameInterval =
+				le32_to_cpup((__le32 *)&buffer[21]);
+			frame->bFrameIntervalType = buffer[25];
+		} else {
+			frame->dwMaxVideoFrameBufferSize = 0;
+			frame->dwDefaultFrameInterval =
+				le32_to_cpup((__le32 *)&buffer[17]);
+			frame->bFrameIntervalType = buffer[21];
+		}
+		frame->dwFrameInterval = *intervals;
+
+		/* Several UVC chipsets screw up dwMaxVideoFrameBufferSize
+		 * completely. Observed behaviours range from setting the
+		 * value to 1.1x the actual frame size of hardwiring the
+		 * 16 low bits to 0. This results in a higher than necessary
+		 * memory usage as well as a wrong image size information. For
+		 * uncompressed formats this can be fixed by computing the
+		 * value from the frame size.
+		 */
+		if (!(format->flags & UVC_FMT_FLAG_COMPRESSED))
+			frame->dwMaxVideoFrameBufferSize = format->bpp
+				* frame->wWidth * frame->wHeight / 8;
+
+		/* Some bogus devices report dwMinFrameInterval equal to
+		 * dwMaxFrameInterval and have dwFrameIntervalStep set to
+		 * zero. Setting all null intervals to 1 fixes the problem and
+		 * some other divisions by zero which could happen.
+		 */
+		for (i = 0; i < n; ++i) {
+			interval = le32_to_cpup((__le32 *)&buffer[26+4*i]);
+			*(*intervals)++ = interval ? interval : 1;
+		}
+
+		/* Make sure that the default frame interval stays between
+		 * the boundaries.
+		 */
+		n -= frame->bFrameIntervalType ? 1 : 2;
+		frame->dwDefaultFrameInterval =
+			min(frame->dwFrameInterval[n],
+			    max(frame->dwFrameInterval[0],
+				frame->dwDefaultFrameInterval));
+
+		uvc_trace(UVC_TRACE_DESCR, "- %ux%u (%u.%u fps)\n",
+			frame->wWidth, frame->wHeight,
+			10000000/frame->dwDefaultFrameInterval,
+			(100000000/frame->dwDefaultFrameInterval)%10);
+
+		format->nframes++;
+		buflen -= buffer[0];
+		buffer += buffer[0];
+	}
+
+	if (buflen > 2 && buffer[2] == VS_STILL_IMAGE_FRAME) {
+		buflen -= buffer[0];
+		buffer += buffer[0];
+	}
+
+	if (buflen > 2 && buffer[2] == VS_COLORFORMAT) {
+		if (buflen < 6) {
+			uvc_trace(UVC_TRACE_DESCR, "device %d videostreaming"
+			       "interface %d COLORFORMAT error\n",
+			       dev->udev->devnum,
+			       alts->desc.bInterfaceNumber);
+			return -EINVAL;
+		}
+
+		format->colorspace = uvc_colorspace(buffer[3]);
+
+		buflen -= buffer[0];
+		buffer += buffer[0];
+	}
+
+	return buffer - start;
+}
+
+static int uvc_parse_streaming(struct uvc_device *dev,
+	struct usb_interface *intf)
+{
+	struct uvc_streaming *streaming = NULL;
+	struct uvc_format *format;
+	struct uvc_frame *frame;
+	struct usb_host_interface *alts = &intf->altsetting[0];
+	unsigned char *_buffer, *buffer = alts->extra;
+	int _buflen, buflen = alts->extralen;
+	unsigned int nformats = 0, nframes = 0, nintervals = 0;
+	unsigned int size, i, n, p;
+	__u32 *interval;
+	__u16 psize;
+	int ret = -EINVAL;
+
+	if (intf->cur_altsetting->desc.bInterfaceSubClass
+		!= SC_VIDEOSTREAMING) {
+		uvc_trace(UVC_TRACE_DESCR, "device %d interface %d isn't a "
+			"video streaming interface\n", dev->udev->devnum,
+			intf->altsetting[0].desc.bInterfaceNumber);
+		return -EINVAL;
+	}
+
+	if (usb_driver_claim_interface(&uvc_driver.driver, intf, dev)) {
+		uvc_trace(UVC_TRACE_DESCR, "device %d interface %d is already "
+			"claimed\n", dev->udev->devnum,
+			intf->altsetting[0].desc.bInterfaceNumber);
+		return -EINVAL;
+	}
+
+	streaming = kzalloc(sizeof *streaming, GFP_KERNEL);
+	if (streaming == NULL) {
+		usb_driver_release_interface(&uvc_driver.driver, intf);
+		return -EINVAL;
+	}
+
+	mutex_init(&streaming->mutex);
+	streaming->intf = usb_get_intf(intf);
+	streaming->intfnum = intf->cur_altsetting->desc.bInterfaceNumber;
+
+	/* The Pico iMage webcam has its class-specific interface descriptors
+	 * after the endpoint descriptors.
+	 */
+	if (buflen == 0) {
+		for (i = 0; i < alts->desc.bNumEndpoints; ++i) {
+			struct usb_host_endpoint *ep = &alts->endpoint[i];
+
+			if (ep->extralen == 0)
+				continue;
+
+			if (ep->extralen > 2 &&
+			    ep->extra[1] == USB_DT_CS_INTERFACE) {
+				uvc_trace(UVC_TRACE_DESCR, "trying extra data "
+					"from endpoint %u.\n", i);
+				buffer = alts->endpoint[i].extra;
+				buflen = alts->endpoint[i].extralen;
+				break;
+			}
+		}
+	}
+
+	/* Skip the standard interface descriptors. */
+	while (buflen > 2 && buffer[1] != USB_DT_CS_INTERFACE) {
+		buflen -= buffer[0];
+		buffer += buffer[0];
+	}
+
+	if (buflen <= 2) {
+		uvc_trace(UVC_TRACE_DESCR, "no class-specific streaming "
+			"interface descriptors found.\n");
+		goto error;
+	}
+
+	/* Parse the header descriptor. */
+	if (buffer[2] == VS_OUTPUT_HEADER) {
+		uvc_trace(UVC_TRACE_DESCR, "device %d videostreaming interface "
+			"%d OUTPUT HEADER descriptor is not supported.\n",
+			dev->udev->devnum, alts->desc.bInterfaceNumber);
+		goto error;
+	} else if (buffer[2] == VS_INPUT_HEADER) {
+		p = buflen >= 5 ? buffer[3] : 0;
+		n = buflen >= 12 ? buffer[12] : 0;
+
+		if (buflen < 13 + p*n || buffer[2] != VS_INPUT_HEADER) {
+			uvc_trace(UVC_TRACE_DESCR, "device %d videostreaming "
+				"interface %d INPUT HEADER descriptor is "
+				"invalid.\n", dev->udev->devnum,
+				alts->desc.bInterfaceNumber);
+			goto error;
+		}
+
+		streaming->header.bNumFormats = p;
+		streaming->header.bEndpointAddress = buffer[6];
+		streaming->header.bmInfo = buffer[7];
+		streaming->header.bTerminalLink = buffer[8];
+		streaming->header.bStillCaptureMethod = buffer[9];
+		streaming->header.bTriggerSupport = buffer[10];
+		streaming->header.bTriggerUsage = buffer[11];
+		streaming->header.bControlSize = n;
+
+		streaming->header.bmaControls = kmalloc(p*n, GFP_KERNEL);
+		if (streaming->header.bmaControls == NULL) {
+			ret = -ENOMEM;
+			goto error;
+		}
+
+		memcpy(streaming->header.bmaControls, &buffer[13], p*n);
+	} else {
+		uvc_trace(UVC_TRACE_DESCR, "device %d videostreaming interface "
+			"%d HEADER descriptor not found.\n", dev->udev->devnum,
+			alts->desc.bInterfaceNumber);
+		goto error;
+	}
+
+	buflen -= buffer[0];
+	buffer += buffer[0];
+
+	_buffer = buffer;
+	_buflen = buflen;
+
+	/* Count the format and frame descriptors. */
+	while (_buflen > 2) {
+		switch (_buffer[2]) {
+		case VS_FORMAT_UNCOMPRESSED:
+		case VS_FORMAT_MJPEG:
+		case VS_FORMAT_FRAME_BASED:
+			nformats++;
+			break;
+
+		case VS_FORMAT_DV:
+			/* DV format has no frame descriptor. We will create a
+			 * dummy frame descriptor with a dummy frame interval.
+			 */
+			nformats++;
+			nframes++;
+			nintervals++;
+			break;
+
+		case VS_FORMAT_MPEG2TS:
+		case VS_FORMAT_STREAM_BASED:
+			uvc_trace(UVC_TRACE_DESCR, "device %d videostreaming "
+				"interface %d FORMAT %u is not supported.\n",
+				dev->udev->devnum,
+				alts->desc.bInterfaceNumber, _buffer[2]);
+			break;
+
+		case VS_FRAME_UNCOMPRESSED:
+		case VS_FRAME_MJPEG:
+			nframes++;
+			if (_buflen > 25)
+				nintervals += _buffer[25] ? _buffer[25] : 3;
+			break;
+
+		case VS_FRAME_FRAME_BASED:
+			nframes++;
+			if (_buflen > 21)
+				nintervals += _buffer[21] ? _buffer[21] : 3;
+			break;
+		}
+
+		_buflen -= _buffer[0];
+		_buffer += _buffer[0];
+	}
+
+	if (nformats == 0) {
+		uvc_trace(UVC_TRACE_DESCR, "device %d videostreaming interface "
+			"%d has no supported formats defined.\n",
+			dev->udev->devnum, alts->desc.bInterfaceNumber);
+		goto error;
+	}
+
+	size = nformats * sizeof *format + nframes * sizeof *frame
+	     + nintervals * sizeof *interval;
+	format = kzalloc(size, GFP_KERNEL);
+	if (format == NULL) {
+		ret = -ENOMEM;
+		goto error;
+	}
+
+	frame = (struct uvc_frame *)&format[nformats];
+	interval = (__u32 *)&frame[nframes];
+
+	streaming->format = format;
+	streaming->nformats = nformats;
+
+	/* Parse the format descriptors. */
+	while (buflen > 2) {
+		switch (buffer[2]) {
+		case VS_FORMAT_UNCOMPRESSED:
+		case VS_FORMAT_MJPEG:
+		case VS_FORMAT_DV:
+		case VS_FORMAT_FRAME_BASED:
+			format->frame = frame;
+			ret = uvc_parse_format(dev, streaming, format,
+				&interval, buffer, buflen);
+			if (ret < 0)
+				goto error;
+
+			frame += format->nframes;
+			format++;
+
+			buflen -= ret;
+			buffer += ret;
+			continue;
+
+		default:
+			break;
+		}
+
+		buflen -= buffer[0];
+		buffer += buffer[0];
+	}
+
+	/* Parse the alternate settings to find the maximum bandwidth. */
+	for (i = 0; i < intf->num_altsetting; ++i) {
+		struct usb_host_endpoint *ep;
+		alts = &intf->altsetting[i];
+		ep = uvc_find_endpoint(alts,
+				streaming->header.bEndpointAddress);
+		if (ep == NULL)
+			continue;
+
+		psize = le16_to_cpu(ep->desc.wMaxPacketSize);
+		psize = (psize & 0x07ff) * (1 + ((psize >> 11) & 3));
+		if (psize > streaming->maxpsize)
+			streaming->maxpsize = psize;
+	}
+
+	list_add_tail(&streaming->list, &dev->streaming);
+	return 0;
+
+error:
+	usb_driver_release_interface(&uvc_driver.driver, intf);
+	usb_put_intf(intf);
+	kfree(streaming->format);
+	kfree(streaming->header.bmaControls);
+	kfree(streaming);
+	return ret;
+}
+
+/* Parse vendor-specific extensions. */
+static int uvc_parse_vendor_control(struct uvc_device *dev,
+	const unsigned char *buffer, int buflen)
+{
+	struct usb_device *udev = dev->udev;
+	struct usb_host_interface *alts = dev->intf->cur_altsetting;
+	struct uvc_entity *unit;
+	unsigned int n, p;
+	int handled = 0;
+
+	switch (le16_to_cpu(dev->udev->descriptor.idVendor)) {
+	case 0x046d:		/* Logitech */
+		if (buffer[1] != 0x41 || buffer[2] != 0x01)
+			break;
+
+		/* Logitech implements several vendor specific functions
+		 * through vendor specific extension units (LXU).
+		 *
+		 * The LXU descriptors are similar to XU descriptors
+		 * (see "USB Device Video Class for Video Devices", section
+		 * 3.7.2.6 "Extension Unit Descriptor") with the following
+		 * differences:
+		 *
+		 * ----------------------------------------------------------
+		 * 0		bLength		1	 Number
+		 *	Size of this descriptor, in bytes: 24+p+n*2
+		 * ----------------------------------------------------------
+		 * 23+p+n	bmControlsType	N	Bitmap
+		 * 	Individual bits in the set are defined:
+		 * 	0: Absolute
+		 * 	1: Relative
+		 *
+		 * 	This bitset is mapped exactly the same as bmControls.
+		 * ----------------------------------------------------------
+		 * 23+p+n*2	bReserved	1	Boolean
+		 * ----------------------------------------------------------
+		 * 24+p+n*2	iExtension	1	Index
+		 *	Index of a string descriptor that describes this
+		 *	extension unit.
+		 * ----------------------------------------------------------
+		 */
+		p = buflen >= 22 ? buffer[21] : 0;
+		n = buflen >= 25 + p ? buffer[22+p] : 0;
+
+		if (buflen < 25 + p + 2*n) {
+			uvc_trace(UVC_TRACE_DESCR, "device %d videocontrol "
+				"interface %d EXTENSION_UNIT error\n",
+				udev->devnum, alts->desc.bInterfaceNumber);
+			break;
+		}
+
+		unit = kzalloc(sizeof *unit + p + 2*n, GFP_KERNEL);
+		if (unit == NULL)
+			return -ENOMEM;
+
+		unit->id = buffer[3];
+		unit->type = VC_EXTENSION_UNIT;
+		memcpy(unit->extension.guidExtensionCode, &buffer[4], 16);
+		unit->extension.bNumControls = buffer[20];
+		unit->extension.bNrInPins =
+			le16_to_cpup((__le16 *)&buffer[21]);
+		unit->extension.baSourceID = (__u8 *)unit + sizeof *unit;
+		memcpy(unit->extension.baSourceID, &buffer[22], p);
+		unit->extension.bControlSize = buffer[22+p];
+		unit->extension.bmControls = (__u8 *)unit + sizeof *unit + p;
+		unit->extension.bmControlsType = (__u8 *)unit + sizeof *unit
+					       + p + n;
+		memcpy(unit->extension.bmControls, &buffer[23+p], 2*n);
+
+		if (buffer[24+p+2*n] != 0)
+			usb_string(udev, buffer[24+p+2*n], unit->name,
+				   sizeof unit->name);
+		else
+			sprintf(unit->name, "Extension %u", buffer[3]);
+
+		list_add_tail(&unit->list, &dev->entities);
+		handled = 1;
+		break;
+	}
+
+	return handled;
+}
+
+static int uvc_parse_standard_control(struct uvc_device *dev,
+	const unsigned char *buffer, int buflen)
+{
+	struct usb_device *udev = dev->udev;
+	struct uvc_entity *unit, *term;
+	struct usb_interface *intf;
+	struct usb_host_interface *alts = dev->intf->cur_altsetting;
+	unsigned int i, n, p, len;
+	__u16 type;
+
+	switch (buffer[2]) {
+	case VC_HEADER:
+		n = buflen >= 12 ? buffer[11] : 0;
+
+		if (buflen < 12 || buflen < 12 + n) {
+			uvc_trace(UVC_TRACE_DESCR, "device %d videocontrol "
+				"interface %d HEADER error\n", udev->devnum,
+				alts->desc.bInterfaceNumber);
+			return -EINVAL;
+		}
+
+		dev->uvc_version = le16_to_cpup((__le16 *)&buffer[3]);
+		dev->clock_frequency = le32_to_cpup((__le32 *)&buffer[7]);
+
+		/* Parse all USB Video Streaming interfaces. */
+		for (i = 0; i < n; ++i) {
+			intf = usb_ifnum_to_if(udev, buffer[12+i]);
+			if (intf == NULL) {
+				uvc_trace(UVC_TRACE_DESCR, "device %d "
+					"interface %d doesn't exists\n",
+					udev->devnum, i);
+				continue;
+			}
+
+			uvc_parse_streaming(dev, intf);
+		}
+		break;
+
+	case VC_INPUT_TERMINAL:
+		if (buflen < 8) {
+			uvc_trace(UVC_TRACE_DESCR, "device %d videocontrol "
+				"interface %d INPUT_TERMINAL error\n",
+				udev->devnum, alts->desc.bInterfaceNumber);
+			return -EINVAL;
+		}
+
+		/* Make sure the terminal type MSB is not null, otherwise it
+		 * could be confused with a unit.
+		 */
+		type = le16_to_cpup((__le16 *)&buffer[4]);
+		if ((type & 0xff00) == 0) {
+			uvc_trace(UVC_TRACE_DESCR, "device %d videocontrol "
+				"interface %d INPUT_TERMINAL %d has invalid "
+				"type 0x%04x, skipping\n", udev->devnum,
+				alts->desc.bInterfaceNumber,
+				buffer[3], type);
+			return 0;
+		}
+
+		n = 0;
+		p = 0;
+		len = 8;
+
+		if (type == ITT_CAMERA) {
+			n = buflen >= 15 ? buffer[14] : 0;
+			len = 15;
+
+		} else if (type == ITT_MEDIA_TRANSPORT_INPUT) {
+			n = buflen >= 9 ? buffer[8] : 0;
+			p = buflen >= 10 + n ? buffer[9+n] : 0;
+			len = 10;
+		}
+
+		if (buflen < len + n + p) {
+			uvc_trace(UVC_TRACE_DESCR, "device %d videocontrol "
+				"interface %d INPUT_TERMINAL error\n",
+				udev->devnum, alts->desc.bInterfaceNumber);
+			return -EINVAL;
+		}
+
+		term = kzalloc(sizeof *term + n + p, GFP_KERNEL);
+		if (term == NULL)
+			return -ENOMEM;
+
+		term->id = buffer[3];
+		term->type = type | UVC_TERM_INPUT;
+
+		if (UVC_ENTITY_TYPE(term) == ITT_CAMERA) {
+			term->camera.bControlSize = n;
+			term->camera.bmControls = (__u8 *)term + sizeof *term;
+			term->camera.wObjectiveFocalLengthMin =
+				le16_to_cpup((__le16 *)&buffer[8]);
+			term->camera.wObjectiveFocalLengthMax =
+				le16_to_cpup((__le16 *)&buffer[10]);
+			term->camera.wOcularFocalLength =
+				le16_to_cpup((__le16 *)&buffer[12]);
+			memcpy(term->camera.bmControls, &buffer[15], n);
+		} else if (UVC_ENTITY_TYPE(term) == ITT_MEDIA_TRANSPORT_INPUT) {
+			term->media.bControlSize = n;
+			term->media.bmControls = (__u8 *)term + sizeof *term;
+			term->media.bTransportModeSize = p;
+			term->media.bmTransportModes = (__u8 *)term
+						     + sizeof *term + n;
+			memcpy(term->media.bmControls, &buffer[9], n);
+			memcpy(term->media.bmTransportModes, &buffer[10+n], p);
+		}
+
+		if (buffer[7] != 0)
+			usb_string(udev, buffer[7], term->name,
+				   sizeof term->name);
+		else if (UVC_ENTITY_TYPE(term) == ITT_CAMERA)
+			sprintf(term->name, "Camera %u", buffer[3]);
+		else if (UVC_ENTITY_TYPE(term) == ITT_MEDIA_TRANSPORT_INPUT)
+			sprintf(term->name, "Media %u", buffer[3]);
+		else
+			sprintf(term->name, "Input %u", buffer[3]);
+
+		list_add_tail(&term->list, &dev->entities);
+		break;
+
+	case VC_OUTPUT_TERMINAL:
+		if (buflen < 9) {
+			uvc_trace(UVC_TRACE_DESCR, "device %d videocontrol "
+				"interface %d OUTPUT_TERMINAL error\n",
+				udev->devnum, alts->desc.bInterfaceNumber);
+			return -EINVAL;
+		}
+
+		/* Make sure the terminal type MSB is not null, otherwise it
+		 * could be confused with a unit.
+		 */
+		type = le16_to_cpup((__le16 *)&buffer[4]);
+		if ((type & 0xff00) == 0) {
+			uvc_trace(UVC_TRACE_DESCR, "device %d videocontrol "
+				"interface %d OUTPUT_TERMINAL %d has invalid "
+				"type 0x%04x, skipping\n", udev->devnum,
+				alts->desc.bInterfaceNumber, buffer[3], type);
+			return 0;
+		}
+
+		term = kzalloc(sizeof *term, GFP_KERNEL);
+		if (term == NULL)
+			return -ENOMEM;
+
+		term->id = buffer[3];
+		term->type = type | UVC_TERM_OUTPUT;
+		term->output.bSourceID = buffer[7];
+
+		if (buffer[8] != 0)
+			usb_string(udev, buffer[8], term->name,
+				   sizeof term->name);
+		else
+			sprintf(term->name, "Output %u", buffer[3]);
+
+		list_add_tail(&term->list, &dev->entities);
+		break;
+
+	case VC_SELECTOR_UNIT:
+		p = buflen >= 5 ? buffer[4] : 0;
+
+		if (buflen < 5 || buflen < 6 + p) {
+			uvc_trace(UVC_TRACE_DESCR, "device %d videocontrol "
+				"interface %d SELECTOR_UNIT error\n",
+				udev->devnum, alts->desc.bInterfaceNumber);
+			return -EINVAL;
+		}
+
+		unit = kzalloc(sizeof *unit + p, GFP_KERNEL);
+		if (unit == NULL)
+			return -ENOMEM;
+
+		unit->id = buffer[3];
+		unit->type = buffer[2];
+		unit->selector.bNrInPins = buffer[4];
+		unit->selector.baSourceID = (__u8 *)unit + sizeof *unit;
+		memcpy(unit->selector.baSourceID, &buffer[5], p);
+
+		if (buffer[5+p] != 0)
+			usb_string(udev, buffer[5+p], unit->name,
+				   sizeof unit->name);
+		else
+			sprintf(unit->name, "Selector %u", buffer[3]);
+
+		list_add_tail(&unit->list, &dev->entities);
+		break;
+
+	case VC_PROCESSING_UNIT:
+		n = buflen >= 8 ? buffer[7] : 0;
+		p = dev->uvc_version >= 0x0110 ? 10 : 9;
+
+		if (buflen < p + n) {
+			uvc_trace(UVC_TRACE_DESCR, "device %d videocontrol "
+				"interface %d PROCESSING_UNIT error\n",
+				udev->devnum, alts->desc.bInterfaceNumber);
+			return -EINVAL;
+		}
+
+		unit = kzalloc(sizeof *unit + n, GFP_KERNEL);
+		if (unit == NULL)
+			return -ENOMEM;
+
+		unit->id = buffer[3];
+		unit->type = buffer[2];
+		unit->processing.bSourceID = buffer[4];
+		unit->processing.wMaxMultiplier =
+			le16_to_cpup((__le16 *)&buffer[5]);
+		unit->processing.bControlSize = buffer[7];
+		unit->processing.bmControls = (__u8 *)unit + sizeof *unit;
+		memcpy(unit->processing.bmControls, &buffer[8], n);
+		if (dev->uvc_version >= 0x0110)
+			unit->processing.bmVideoStandards = buffer[9+n];
+
+		if (buffer[8+n] != 0)
+			usb_string(udev, buffer[8+n], unit->name,
+				   sizeof unit->name);
+		else
+			sprintf(unit->name, "Processing %u", buffer[3]);
+
+		list_add_tail(&unit->list, &dev->entities);
+		break;
+
+	case VC_EXTENSION_UNIT:
+		p = buflen >= 22 ? buffer[21] : 0;
+		n = buflen >= 24 + p ? buffer[22+p] : 0;
+
+		if (buflen < 24 + p + n) {
+			uvc_trace(UVC_TRACE_DESCR, "device %d videocontrol "
+				"interface %d EXTENSION_UNIT error\n",
+				udev->devnum, alts->desc.bInterfaceNumber);
+			return -EINVAL;
+		}
+
+		unit = kzalloc(sizeof *unit + p + n, GFP_KERNEL);
+		if (unit == NULL)
+			return -ENOMEM;
+
+		unit->id = buffer[3];
+		unit->type = buffer[2];
+		memcpy(unit->extension.guidExtensionCode, &buffer[4], 16);
+		unit->extension.bNumControls = buffer[20];
+		unit->extension.bNrInPins =
+			le16_to_cpup((__le16 *)&buffer[21]);
+		unit->extension.baSourceID = (__u8 *)unit + sizeof *unit;
+		memcpy(unit->extension.baSourceID, &buffer[22], p);
+		unit->extension.bControlSize = buffer[22+p];
+		unit->extension.bmControls = (__u8 *)unit + sizeof *unit + p;
+		memcpy(unit->extension.bmControls, &buffer[23+p], n);
+
+		if (buffer[23+p+n] != 0)
+			usb_string(udev, buffer[23+p+n], unit->name,
+				   sizeof unit->name);
+		else
+			sprintf(unit->name, "Extension %u", buffer[3]);
+
+		list_add_tail(&unit->list, &dev->entities);
+		break;
+
+	default:
+		uvc_trace(UVC_TRACE_DESCR, "Found an unknown CS_INTERFACE "
+			"descriptor (%u)\n", buffer[2]);
+		break;
+	}
+
+	return 0;
+}
+
+static int uvc_parse_control(struct uvc_device *dev)
+{
+	struct usb_host_interface *alts = dev->intf->cur_altsetting;
+	unsigned char *buffer = alts->extra;
+	int buflen = alts->extralen;
+	int ret;
+
+	/* Parse the default alternate setting only, as the UVC specification
+	 * defines a single alternate setting, the default alternate setting
+	 * zero.
+	 */
+
+	while (buflen > 2) {
+		if (uvc_parse_vendor_control(dev, buffer, buflen) ||
+		    buffer[1] != USB_DT_CS_INTERFACE)
+			goto next_descriptor;
+
+		if ((ret = uvc_parse_standard_control(dev, buffer, buflen)) < 0)
+			return ret;
+
+next_descriptor:
+		buflen -= buffer[0];
+		buffer += buffer[0];
+	}
+
+	/* Check if the optional status endpoint is present. */
+	if (alts->desc.bNumEndpoints == 1) {
+		struct usb_host_endpoint *ep = &alts->endpoint[0];
+		struct usb_endpoint_descriptor *desc = &ep->desc;
+
+		if (usb_endpoint_is_int_in(desc) &&
+		    le16_to_cpu(desc->wMaxPacketSize) >= 8 &&
+		    desc->bInterval != 0) {
+			uvc_trace(UVC_TRACE_DESCR, "Found a Status endpoint "
+				"(addr %02x).\n", desc->bEndpointAddress);
+			dev->int_ep = ep;
+		}
+	}
+
+	return 0;
+}
+
+/* ------------------------------------------------------------------------
+ * USB probe and disconnect
+ */
+
+/*
+ * Unregister the video devices.
+ */
+static void uvc_unregister_video(struct uvc_device *dev)
+{
+	if (dev->video.vdev) {
+		if (dev->video.vdev->minor == -1)
+			video_device_release(dev->video.vdev);
+		else
+			video_unregister_device(dev->video.vdev);
+		dev->video.vdev = NULL;
+	}
+}
+
+/*
+ * Scan the UVC descriptors to locate a chain starting at an Output Terminal
+ * and containing the following units:
+ *
+ * - a USB Streaming Output Terminal
+ * - zero or one Processing Unit
+ * - zero, one or mode single-input Selector Units
+ * - zero or one multiple-input Selector Units, provided all inputs are
+ *   connected to input terminals
+ * - zero, one or mode single-input Extension Units
+ * - one Camera Input Terminal, or one or more External terminals.
+ *
+ * A side forward scan is made on each detected entity to check for additional
+ * extension units.
+ */
+static int uvc_scan_chain_entity(struct uvc_video_device *video,
+	struct uvc_entity *entity)
+{
+	switch (UVC_ENTITY_TYPE(entity)) {
+	case VC_EXTENSION_UNIT:
+		if (uvc_trace_param & UVC_TRACE_PROBE)
+			printk(" <- XU %d", entity->id);
+
+		if (entity->extension.bNrInPins != 1) {
+			uvc_trace(UVC_TRACE_DESCR, "Extension unit %d has more "
+				"than 1 input pin.\n", entity->id);
+			return -1;
+		}
+
+		list_add_tail(&entity->chain, &video->extensions);
+		break;
+
+	case VC_PROCESSING_UNIT:
+		if (uvc_trace_param & UVC_TRACE_PROBE)
+			printk(" <- PU %d", entity->id);
+
+		if (video->processing != NULL) {
+			uvc_trace(UVC_TRACE_DESCR, "Found multiple "
+				"Processing Units in chain.\n");
+			return -1;
+		}
+
+		video->processing = entity;
+		break;
+
+	case VC_SELECTOR_UNIT:
+		if (uvc_trace_param & UVC_TRACE_PROBE)
+			printk(" <- SU %d", entity->id);
+
+		/* Single-input selector units are ignored. */
+		if (entity->selector.bNrInPins == 1)
+			break;
+
+		if (video->selector != NULL) {
+			uvc_trace(UVC_TRACE_DESCR, "Found multiple Selector "
+				"Units in chain.\n");
+			return -1;
+		}
+
+		video->selector = entity;
+		break;
+
+	case ITT_VENDOR_SPECIFIC:
+	case ITT_CAMERA:
+	case ITT_MEDIA_TRANSPORT_INPUT:
+		if (uvc_trace_param & UVC_TRACE_PROBE)
+			printk(" <- IT %d\n", entity->id);
+
+		list_add_tail(&entity->chain, &video->iterms);
+		break;
+
+	default:
+		uvc_trace(UVC_TRACE_DESCR, "Unsupported entity type "
+			"0x%04x found in chain.\n", UVC_ENTITY_TYPE(entity));
+		return -1;
+	}
+
+	return 0;
+}
+
+static int uvc_scan_chain_forward(struct uvc_video_device *video,
+	struct uvc_entity *entity, struct uvc_entity *prev)
+{
+	struct uvc_entity *forward;
+	int found;
+
+	/* Forward scan */
+	forward = NULL;
+	found = 0;
+
+	while (1) {
+		forward = uvc_entity_by_reference(video->dev, entity->id,
+			forward);
+		if (forward == NULL)
+			break;
+
+		if (UVC_ENTITY_TYPE(forward) != VC_EXTENSION_UNIT ||
+		    forward == prev)
+			continue;
+
+		if (forward->extension.bNrInPins != 1) {
+			uvc_trace(UVC_TRACE_DESCR, "Extension unit %d has"
+				"more than 1 input pin.\n", entity->id);
+			return -1;
+		}
+
+		list_add_tail(&forward->chain, &video->extensions);
+		if (uvc_trace_param & UVC_TRACE_PROBE) {
+			if (!found)
+				printk(" (-> XU");
+
+			printk(" %d", forward->id);
+			found = 1;
+		}
+	}
+	if (found)
+		printk(")");
+
+	return 0;
+}
+
+static int uvc_scan_chain_backward(struct uvc_video_device *video,
+	struct uvc_entity *entity)
+{
+	struct uvc_entity *term;
+	int id = -1, i;
+
+	switch (UVC_ENTITY_TYPE(entity)) {
+	case VC_EXTENSION_UNIT:
+		id = entity->extension.baSourceID[0];
+		break;
+
+	case VC_PROCESSING_UNIT:
+		id = entity->processing.bSourceID;
+		break;
+
+	case VC_SELECTOR_UNIT:
+		/* Single-input selector units are ignored. */
+		if (entity->selector.bNrInPins == 1) {
+			id = entity->selector.baSourceID[0];
+			break;
+		}
+
+		if (uvc_trace_param & UVC_TRACE_PROBE)
+			printk(" <- IT");
+
+		video->selector = entity;
+		for (i = 0; i < entity->selector.bNrInPins; ++i) {
+			id = entity->selector.baSourceID[i];
+			term = uvc_entity_by_id(video->dev, id);
+			if (term == NULL || !UVC_ENTITY_IS_ITERM(term)) {
+				uvc_trace(UVC_TRACE_DESCR, "Selector unit %d "
+					"input %d isn't connected to an "
+					"input terminal\n", entity->id, i);
+				return -1;
+			}
+
+			if (uvc_trace_param & UVC_TRACE_PROBE)
+				printk(" %d", term->id);
+
+			list_add_tail(&term->chain, &video->iterms);
+			uvc_scan_chain_forward(video, term, entity);
+		}
+
+		if (uvc_trace_param & UVC_TRACE_PROBE)
+			printk("\n");
+
+		id = 0;
+		break;
+	}
+
+	return id;
+}
+
+static int uvc_scan_chain(struct uvc_video_device *video)
+{
+	struct uvc_entity *entity, *prev;
+	int id;
+
+	entity = video->oterm;
+	uvc_trace(UVC_TRACE_PROBE, "Scanning UVC chain: OT %d", entity->id);
+	id = entity->output.bSourceID;
+	while (id != 0) {
+		prev = entity;
+		entity = uvc_entity_by_id(video->dev, id);
+		if (entity == NULL) {
+			uvc_trace(UVC_TRACE_DESCR, "Found reference to "
+				"unknown entity %d.\n", id);
+			return -1;
+		}
+
+		/* Process entity */
+		if (uvc_scan_chain_entity(video, entity) < 0)
+			return -1;
+
+		/* Forward scan */
+		if (uvc_scan_chain_forward(video, entity, prev) < 0)
+			return -1;
+
+		/* Stop when a terminal is found. */
+		if (!UVC_ENTITY_IS_UNIT(entity))
+			break;
+
+		/* Backward scan */
+		id = uvc_scan_chain_backward(video, entity);
+		if (id < 0)
+			return id;
+	}
+
+	/* Initialize the video buffers queue. */
+	uvc_queue_init(&video->queue);
+
+	return 0;
+}
+
+/*
+ * Register the video devices.
+ *
+ * The driver currently supports a single video device per control interface
+ * only. The terminal and units must match the following structure:
+ *
+ * ITT_CAMERA -> VC_PROCESSING_UNIT -> VC_EXTENSION_UNIT{0,n} -> TT_STREAMING
+ *
+ * The Extension Units, if present, must have a single input pin. The
+ * Processing Unit and Extension Units can be in any order. Additional
+ * Extension Units connected to the main chain as single-unit branches are
+ * also supported.
+ */
+static int uvc_register_video(struct uvc_device *dev)
+{
+	struct video_device *vdev;
+	struct uvc_entity *term;
+	int found = 0, ret;
+
+	/* Check if the control interface matches the structure we expect. */
+	list_for_each_entry(term, &dev->entities, list) {
+		struct uvc_streaming *streaming;
+
+		if (UVC_ENTITY_TYPE(term) != TT_STREAMING)
+			continue;
+
+		memset(&dev->video, 0, sizeof dev->video);
+		mutex_init(&dev->video.ctrl_mutex);
+		INIT_LIST_HEAD(&dev->video.iterms);
+		INIT_LIST_HEAD(&dev->video.extensions);
+		dev->video.oterm = term;
+		dev->video.dev = dev;
+		if (uvc_scan_chain(&dev->video) < 0)
+			continue;
+
+		list_for_each_entry(streaming, &dev->streaming, list) {
+			if (streaming->header.bTerminalLink == term->id) {
+				dev->video.streaming = streaming;
+				found = 1;
+				break;
+			}
+		}
+
+		if (found)
+			break;
+	}
+
+	if (!found) {
+		uvc_printk(KERN_INFO, "No valid video chain found.\n");
+		return -1;
+	}
+
+	if (uvc_trace_param & UVC_TRACE_PROBE) {
+		uvc_printk(KERN_INFO, "Found a valid video chain (");
+		list_for_each_entry(term, &dev->video.iterms, chain) {
+			printk("%d", term->id);
+			if (term->chain.next != &dev->video.iterms)
+				printk(",");
+		}
+		printk(" -> %d).\n", dev->video.oterm->id);
+	}
+
+	/* Initialize the streaming interface with default streaming
+	 * parameters.
+	 */
+	if ((ret = uvc_video_init(&dev->video)) < 0) {
+		uvc_printk(KERN_ERR, "Failed to initialize the device "
+			"(%d).\n", ret);
+		return ret;
+	}
+
+	/* Register the device with V4L. */
+	vdev = video_device_alloc();
+	if (vdev == NULL)
+		return -1;
+
+	/* We already hold a reference to dev->udev. The video device will be
+	 * unregistered before the reference is released, so we don't need to
+	 * get another one.
+	 */
+	vdev->dev = &dev->intf->dev;
+	vdev->type = 0;
+	vdev->type2 = 0;
+	vdev->minor = -1;
+	vdev->fops = &uvc_fops;
+	vdev->release = video_device_release;
+	strncpy(vdev->name, dev->name, sizeof vdev->name);
+
+	/* Set the driver data before calling video_register_device, otherwise
+	 * uvc_v4l2_open might race us.
+	 *
+	 * FIXME: usb_set_intfdata hasn't been called so far. Is that a
+	 * 	  problem ? Does any function which could be called here get
+	 * 	  a pointer to the usb_interface ?
+	 */
+	dev->video.vdev = vdev;
+	video_set_drvdata(vdev, &dev->video);
+
+	if (video_register_device(vdev, VFL_TYPE_GRABBER, -1) < 0) {
+		dev->video.vdev = NULL;
+		video_device_release(vdev);
+		return -1;
+	}
+
+	return 0;
+}
+
+/*
+ * Delete the UVC device.
+ *
+ * Called by the kernel when the last reference to the uvc_device structure
+ * is released.
+ *
+ * Unregistering the video devices is done here because every opened instance
+ * must be closed before the device can be unregistered. An alternative would
+ * have been to use another reference count for uvc_v4l2_open/uvc_release, and
+ * unregister the video devices on disconnect when that reference count drops
+ * to zero.
+ *
+ * As this function is called after or during disconnect(), all URBs have
+ * already been canceled by the USB core. There is no need to kill the
+ * interrupt URB manually.
+ */
+void uvc_delete(struct kref *kref)
+{
+	struct uvc_device *dev = container_of(kref, struct uvc_device, kref);
+	struct list_head *p, *n;
+
+	/* Unregister the video device */
+	uvc_unregister_video(dev);
+	usb_put_intf(dev->intf);
+	usb_put_dev(dev->udev);
+
+	uvc_status_cleanup(dev);
+	uvc_ctrl_cleanup_device(dev);
+
+	list_for_each_safe(p, n, &dev->entities) {
+		struct uvc_entity *entity;
+		entity = list_entry(p, struct uvc_entity, list);
+		kfree(entity);
+	}
+
+	list_for_each_safe(p, n, &dev->streaming) {
+		struct uvc_streaming *streaming;
+		streaming = list_entry(p, struct uvc_streaming, list);
+		usb_driver_release_interface(&uvc_driver.driver,
+			streaming->intf);
+		usb_put_intf(streaming->intf);
+		kfree(streaming->format);
+		kfree(streaming->header.bmaControls);
+		kfree(streaming);
+	}
+
+	kfree(dev);
+}
+
+static int uvc_probe(struct usb_interface *intf,
+		     const struct usb_device_id *id)
+{
+	struct usb_device *udev = interface_to_usbdev(intf);
+	struct uvc_device *dev;
+	int ret;
+
+	if (id->idVendor && id->idProduct)
+		uvc_trace(UVC_TRACE_PROBE, "Probing known UVC device %s "
+				"(%04x:%04x)\n", udev->devpath, id->idVendor,
+				id->idProduct);
+	else
+		uvc_trace(UVC_TRACE_PROBE, "Probing generic UVC device %s\n",
+				udev->devpath);
+
+	/* Allocate memory for the device and initialize it */
+	if ((dev = kzalloc(sizeof *dev, GFP_KERNEL)) == NULL)
+		return -ENOMEM;
+
+	INIT_LIST_HEAD(&dev->entities);
+	INIT_LIST_HEAD(&dev->streaming);
+	kref_init(&dev->kref);
+
+	dev->udev = usb_get_dev(udev);
+	dev->intf = usb_get_intf(intf);
+	dev->intfnum = intf->cur_altsetting->desc.bInterfaceNumber;
+	dev->quirks = id->driver_info | uvc_quirks_param;
+
+	if (udev->product != NULL)
+		strncpy(dev->name, udev->product, sizeof dev->name);
+	else
+		snprintf(dev->name, sizeof dev->name,
+			"UVC Camera (%04x:%04x)",
+			le16_to_cpu(udev->descriptor.idVendor),
+			le16_to_cpu(udev->descriptor.idProduct));
+
+	/* Parse the Video Class control descriptor */
+	if (uvc_parse_control(dev) < 0) {
+		uvc_trace(UVC_TRACE_PROBE, "Unable to parse UVC "
+			"descriptors.\n");
+		goto error;
+	}
+
+	uvc_printk(KERN_INFO, "Found UVC %u.%02u device %s (%04x:%04x)\n",
+		dev->uvc_version >> 8, dev->uvc_version & 0xff,
+		udev->product ? udev->product : "<unnamed>",
+		le16_to_cpu(udev->descriptor.idVendor),
+		le16_to_cpu(udev->descriptor.idProduct));
+
+	if (uvc_quirks_param != 0) {
+		uvc_printk(KERN_INFO, "Forcing device quirks 0x%x by module "
+			"parameter for testing purpose.\n", uvc_quirks_param);
+		uvc_printk(KERN_INFO, "Please report required quirks to the "
+			"linux-uvc-devel mailing list.\n");
+	}
+
+	/* Initialize controls */
+	if (uvc_ctrl_init_device(dev) < 0)
+		goto error;
+
+	/* Register the video devices */
+	if (uvc_register_video(dev) < 0)
+		goto error;
+
+	/* Save our data pointer in the interface data */
+	usb_set_intfdata(intf, dev);
+
+	/* Initialize the interrupt URB */
+	if ((ret = uvc_status_init(dev)) < 0) {
+		uvc_printk(KERN_INFO, "Unable to initialize the status "
+			"endpoint (%d), status interrupt will not be "
+			"supported.\n", ret);
+	}
+
+	uvc_trace(UVC_TRACE_PROBE, "UVC device initialized.\n");
+	return 0;
+
+error:
+	kref_put(&dev->kref, uvc_delete);
+	return -ENODEV;
+}
+
+static void uvc_disconnect(struct usb_interface *intf)
+{
+	struct uvc_device *dev = usb_get_intfdata(intf);
+
+	/* Set the USB interface data to NULL. This can be done outside the
+	 * lock, as there's no other reader.
+	 */
+	usb_set_intfdata(intf, NULL);
+
+	if (intf->cur_altsetting->desc.bInterfaceSubClass == SC_VIDEOSTREAMING)
+		return;
+
+	/* uvc_v4l2_open() might race uvc_disconnect(). A static driver-wide
+	 * lock is needed to prevent uvc_disconnect from releasing its
+	 * reference to the uvc_device instance after uvc_v4l2_open() received
+	 * the pointer to the device (video_devdata) but before it got the
+	 * chance to increase the reference count (kref_get).
+	 */
+	mutex_lock(&uvc_driver.open_mutex);
+
+	dev->state |= UVC_DEV_DISCONNECTED;
+	kref_put(&dev->kref, uvc_delete);
+
+	mutex_unlock(&uvc_driver.open_mutex);
+}
+
+static int uvc_suspend(struct usb_interface *intf, pm_message_t message)
+{
+	struct uvc_device *dev = usb_get_intfdata(intf);
+
+	uvc_trace(UVC_TRACE_SUSPEND, "Suspending interface %u\n",
+		intf->cur_altsetting->desc.bInterfaceNumber);
+
+	/* Controls are cached on the fly so they don't need to be saved. */
+	if (intf->cur_altsetting->desc.bInterfaceSubClass == SC_VIDEOCONTROL)
+		return uvc_status_suspend(dev);
+
+	if (dev->video.streaming->intf != intf) {
+		uvc_trace(UVC_TRACE_SUSPEND, "Suspend: video streaming USB "
+				"interface mismatch.\n");
+		return -EINVAL;
+	}
+
+	return uvc_video_suspend(&dev->video);
+}
+
+static int uvc_resume(struct usb_interface *intf)
+{
+	struct uvc_device *dev = usb_get_intfdata(intf);
+	int ret;
+
+	uvc_trace(UVC_TRACE_SUSPEND, "Resuming interface %u\n",
+		intf->cur_altsetting->desc.bInterfaceNumber);
+
+	if (intf->cur_altsetting->desc.bInterfaceSubClass == SC_VIDEOCONTROL) {
+		if ((ret = uvc_ctrl_resume_device(dev)) < 0)
+			return ret;
+
+		return uvc_status_resume(dev);
+	}
+
+	if (dev->video.streaming->intf != intf) {
+		uvc_trace(UVC_TRACE_SUSPEND, "Resume: video streaming USB "
+				"interface mismatch.\n");
+		return -EINVAL;
+	}
+
+	return uvc_video_resume(&dev->video);
+}
+
+/* ------------------------------------------------------------------------
+ * Driver initialization and cleanup
+ */
+
+/*
+ * The Logitech cameras listed below have their interface class set to
+ * VENDOR_SPEC because they don't announce themselves as UVC devices, even
+ * though they are compliant.
+ */
+static struct usb_device_id uvc_ids[] = {
+	/* ALi M5606 (Clevo M540SR) */
+	{ .match_flags		= USB_DEVICE_ID_MATCH_DEVICE
+				| USB_DEVICE_ID_MATCH_INT_INFO,
+	  .idVendor		= 0x0402,
+	  .idProduct		= 0x5606,
+	  .bInterfaceClass	= USB_CLASS_VIDEO,
+	  .bInterfaceSubClass	= 1,
+	  .bInterfaceProtocol	= 0,
+	  .driver_info		= UVC_QUIRK_PROBE_MINMAX },
+	/* Creative Live! Optia */
+	{ .match_flags		= USB_DEVICE_ID_MATCH_DEVICE
+				| USB_DEVICE_ID_MATCH_INT_INFO,
+	  .idVendor		= 0x041e,
+	  .idProduct		= 0x4057,
+	  .bInterfaceClass	= USB_CLASS_VIDEO,
+	  .bInterfaceSubClass	= 1,
+	  .bInterfaceProtocol	= 0,
+	  .driver_info		= UVC_QUIRK_PROBE_MINMAX },
+	/* Microsoft Lifecam NX-6000 */
+	{ .match_flags		= USB_DEVICE_ID_MATCH_DEVICE
+				| USB_DEVICE_ID_MATCH_INT_INFO,
+	  .idVendor		= 0x045e,
+	  .idProduct		= 0x00f8,
+	  .bInterfaceClass	= USB_CLASS_VIDEO,
+	  .bInterfaceSubClass	= 1,
+	  .bInterfaceProtocol	= 0,
+	  .driver_info		= UVC_QUIRK_PROBE_MINMAX },
+	/* Microsoft Lifecam VX-7000 */
+	{ .match_flags		= USB_DEVICE_ID_MATCH_DEVICE
+				| USB_DEVICE_ID_MATCH_INT_INFO,
+	  .idVendor		= 0x045e,
+	  .idProduct		= 0x0723,
+	  .bInterfaceClass	= USB_CLASS_VIDEO,
+	  .bInterfaceSubClass	= 1,
+	  .bInterfaceProtocol	= 0,
+	  .driver_info		= UVC_QUIRK_PROBE_MINMAX },
+	/* Logitech Quickcam Fusion */
+	{ .match_flags		= USB_DEVICE_ID_MATCH_DEVICE
+				| USB_DEVICE_ID_MATCH_INT_INFO,
+	  .idVendor		= 0x046d,
+	  .idProduct		= 0x08c1,
+	  .bInterfaceClass	= USB_CLASS_VENDOR_SPEC,
+	  .bInterfaceSubClass	= 1,
+	  .bInterfaceProtocol	= 0 },
+	/* Logitech Quickcam Orbit MP */
+	{ .match_flags		= USB_DEVICE_ID_MATCH_DEVICE
+				| USB_DEVICE_ID_MATCH_INT_INFO,
+	  .idVendor		= 0x046d,
+	  .idProduct		= 0x08c2,
+	  .bInterfaceClass	= USB_CLASS_VENDOR_SPEC,
+	  .bInterfaceSubClass	= 1,
+	  .bInterfaceProtocol	= 0 },
+	/* Logitech Quickcam Pro for Notebook */
+	{ .match_flags		= USB_DEVICE_ID_MATCH_DEVICE
+				| USB_DEVICE_ID_MATCH_INT_INFO,
+	  .idVendor		= 0x046d,
+	  .idProduct		= 0x08c3,
+	  .bInterfaceClass	= USB_CLASS_VENDOR_SPEC,
+	  .bInterfaceSubClass	= 1,
+	  .bInterfaceProtocol	= 0 },
+	/* Logitech Quickcam Pro 5000 */
+	{ .match_flags		= USB_DEVICE_ID_MATCH_DEVICE
+				| USB_DEVICE_ID_MATCH_INT_INFO,
+	  .idVendor		= 0x046d,
+	  .idProduct		= 0x08c5,
+	  .bInterfaceClass	= USB_CLASS_VENDOR_SPEC,
+	  .bInterfaceSubClass	= 1,
+	  .bInterfaceProtocol	= 0 },
+	/* Logitech Quickcam OEM Dell Notebook */
+	{ .match_flags		= USB_DEVICE_ID_MATCH_DEVICE
+				| USB_DEVICE_ID_MATCH_INT_INFO,
+	  .idVendor		= 0x046d,
+	  .idProduct		= 0x08c6,
+	  .bInterfaceClass	= USB_CLASS_VENDOR_SPEC,
+	  .bInterfaceSubClass	= 1,
+	  .bInterfaceProtocol	= 0 },
+	/* Logitech Quickcam OEM Cisco VT Camera II */
+	{ .match_flags		= USB_DEVICE_ID_MATCH_DEVICE
+				| USB_DEVICE_ID_MATCH_INT_INFO,
+	  .idVendor		= 0x046d,
+	  .idProduct		= 0x08c7,
+	  .bInterfaceClass	= USB_CLASS_VENDOR_SPEC,
+	  .bInterfaceSubClass	= 1,
+	  .bInterfaceProtocol	= 0 },
+	/* Apple Built-In iSight */
+	{ .match_flags          = USB_DEVICE_ID_MATCH_DEVICE
+				| USB_DEVICE_ID_MATCH_INT_INFO,
+	  .idVendor		= 0x05ac,
+	  .idProduct		= 0x8501,
+	  .bInterfaceClass      = USB_CLASS_VIDEO,
+	  .bInterfaceSubClass   = 1,
+	  .bInterfaceProtocol   = 0,
+	  .driver_info 		= UVC_QUIRK_PROBE_MINMAX
+				| UVC_QUIRK_BUILTIN_ISIGHT },
+	/* Genesys Logic USB 2.0 PC Camera */
+	{ .match_flags          = USB_DEVICE_ID_MATCH_DEVICE
+				| USB_DEVICE_ID_MATCH_INT_INFO,
+	  .idVendor             = 0x05e3,
+	  .idProduct            = 0x0505,
+	  .bInterfaceClass      = USB_CLASS_VIDEO,
+	  .bInterfaceSubClass   = 1,
+	  .bInterfaceProtocol   = 0,
+	  .driver_info          = UVC_QUIRK_STREAM_NO_FID },
+	/* Silicon Motion SM371 */
+	{ .match_flags		= USB_DEVICE_ID_MATCH_DEVICE
+				| USB_DEVICE_ID_MATCH_INT_INFO,
+	  .idVendor		= 0x090c,
+	  .idProduct		= 0xb371,
+	  .bInterfaceClass	= USB_CLASS_VIDEO,
+	  .bInterfaceSubClass	= 1,
+	  .bInterfaceProtocol	= 0,
+	  .driver_info		= UVC_QUIRK_PROBE_MINMAX },
+	/* MT6227 */
+	{ .match_flags		= USB_DEVICE_ID_MATCH_DEVICE
+				| USB_DEVICE_ID_MATCH_INT_INFO,
+	  .idVendor		= 0x0e8d,
+	  .idProduct		= 0x0004,
+	  .bInterfaceClass	= USB_CLASS_VIDEO,
+	  .bInterfaceSubClass	= 1,
+	  .bInterfaceProtocol	= 0,
+	  .driver_info		= UVC_QUIRK_PROBE_MINMAX },
+	/* Syntek (HP Spartan) */
+	{ .match_flags		= USB_DEVICE_ID_MATCH_DEVICE
+				| USB_DEVICE_ID_MATCH_INT_INFO,
+	  .idVendor		= 0x174f,
+	  .idProduct		= 0x5212,
+	  .bInterfaceClass	= USB_CLASS_VIDEO,
+	  .bInterfaceSubClass	= 1,
+	  .bInterfaceProtocol	= 0,
+	  .driver_info		= UVC_QUIRK_STREAM_NO_FID },
+	/* Syntek (Asus U3S) */
+	{ .match_flags		= USB_DEVICE_ID_MATCH_DEVICE
+				| USB_DEVICE_ID_MATCH_INT_INFO,
+	  .idVendor		= 0x174f,
+	  .idProduct		= 0x8a33,
+	  .bInterfaceClass	= USB_CLASS_VIDEO,
+	  .bInterfaceSubClass	= 1,
+	  .bInterfaceProtocol	= 0,
+	  .driver_info		= UVC_QUIRK_STREAM_NO_FID },
+	/* Ecamm Pico iMage */
+	{ .match_flags		= USB_DEVICE_ID_MATCH_DEVICE
+				| USB_DEVICE_ID_MATCH_INT_INFO,
+	  .idVendor		= 0x18cd,
+	  .idProduct		= 0xcafe,
+	  .bInterfaceClass	= USB_CLASS_VIDEO,
+	  .bInterfaceSubClass	= 1,
+	  .bInterfaceProtocol	= 0,
+	  .driver_info		= UVC_QUIRK_PROBE_EXTRAFIELDS },
+	/* Bodelin ProScopeHR */
+	{ .match_flags		= USB_DEVICE_ID_MATCH_DEVICE
+				| USB_DEVICE_ID_MATCH_DEV_HI
+				| USB_DEVICE_ID_MATCH_INT_INFO,
+	  .idVendor		= 0x19ab,
+	  .idProduct		= 0x1000,
+	  .bcdDevice_hi		= 0x0126,
+	  .bInterfaceClass	= USB_CLASS_VIDEO,
+	  .bInterfaceSubClass	= 1,
+	  .bInterfaceProtocol	= 0,
+	  .driver_info		= UVC_QUIRK_STATUS_INTERVAL },
+	/* SiGma Micro USB Web Camera */
+	{ .match_flags		= USB_DEVICE_ID_MATCH_DEVICE
+				| USB_DEVICE_ID_MATCH_INT_INFO,
+	  .idVendor		= 0x1c4f,
+	  .idProduct		= 0x3000,
+	  .bInterfaceClass	= USB_CLASS_VIDEO,
+	  .bInterfaceSubClass	= 1,
+	  .bInterfaceProtocol	= 0,
+	  .driver_info		= UVC_QUIRK_PROBE_MINMAX
+				| UVC_QUIRK_IGNORE_SELECTOR_UNIT},
+	/* Acer OEM Webcam - Unknown vendor */
+	{ .match_flags		= USB_DEVICE_ID_MATCH_DEVICE
+				| USB_DEVICE_ID_MATCH_INT_INFO,
+	  .idVendor		= 0x5986,
+	  .idProduct		= 0x0100,
+	  .bInterfaceClass	= USB_CLASS_VIDEO,
+	  .bInterfaceSubClass	= 1,
+	  .bInterfaceProtocol	= 0,
+	  .driver_info		= UVC_QUIRK_PROBE_MINMAX },
+	/* Packard Bell OEM Webcam */
+	{ .match_flags		= USB_DEVICE_ID_MATCH_DEVICE
+				| USB_DEVICE_ID_MATCH_INT_INFO,
+	  .idVendor		= 0x5986,
+	  .idProduct		= 0x0101,
+	  .bInterfaceClass	= USB_CLASS_VIDEO,
+	  .bInterfaceSubClass	= 1,
+	  .bInterfaceProtocol	= 0,
+	  .driver_info		= UVC_QUIRK_PROBE_MINMAX },
+	/* Acer Crystal Eye webcam */
+	{ .match_flags		= USB_DEVICE_ID_MATCH_DEVICE
+				| USB_DEVICE_ID_MATCH_INT_INFO,
+	  .idVendor		= 0x5986,
+	  .idProduct		= 0x0102,
+	  .bInterfaceClass	= USB_CLASS_VIDEO,
+	  .bInterfaceSubClass	= 1,
+	  .bInterfaceProtocol	= 0,
+	  .driver_info		= UVC_QUIRK_PROBE_MINMAX },
+	/* Acer OrbiCam - Unknown vendor */
+	{ .match_flags		= USB_DEVICE_ID_MATCH_DEVICE
+				| USB_DEVICE_ID_MATCH_INT_INFO,
+	  .idVendor		= 0x5986,
+	  .idProduct		= 0x0200,
+	  .bInterfaceClass	= USB_CLASS_VIDEO,
+	  .bInterfaceSubClass	= 1,
+	  .bInterfaceProtocol	= 0,
+	  .driver_info		= UVC_QUIRK_PROBE_MINMAX },
+	/* Generic USB Video Class */
+	{ USB_INTERFACE_INFO(USB_CLASS_VIDEO, 1, 0) },
+	{}
+};
+
+MODULE_DEVICE_TABLE(usb, uvc_ids);
+
+struct uvc_driver uvc_driver = {
+	.driver = {
+		.name		= "uvcvideo",
+		.probe		= uvc_probe,
+		.disconnect	= uvc_disconnect,
+		.suspend	= uvc_suspend,
+		.resume		= uvc_resume,
+		.id_table	= uvc_ids,
+		.supports_autosuspend = 1,
+	},
+};
+
+static int __init uvc_init(void)
+{
+	int result;
+
+	INIT_LIST_HEAD(&uvc_driver.devices);
+	INIT_LIST_HEAD(&uvc_driver.controls);
+	mutex_init(&uvc_driver.open_mutex);
+	mutex_init(&uvc_driver.ctrl_mutex);
+
+	uvc_ctrl_init();
+
+	result = usb_register(&uvc_driver.driver);
+	if (result == 0)
+		printk(KERN_INFO DRIVER_DESC " (" DRIVER_VERSION ")\n");
+	return result;
+}
+
+static void __exit uvc_cleanup(void)
+{
+	usb_deregister(&uvc_driver.driver);
+}
+
+module_init(uvc_init);
+module_exit(uvc_cleanup);
+
+module_param_named(quirks, uvc_quirks_param, uint, S_IRUGO|S_IWUSR);
+MODULE_PARM_DESC(quirks, "Forced device quirks");
+module_param_named(trace, uvc_trace_param, uint, S_IRUGO|S_IWUSR);
+MODULE_PARM_DESC(trace, "Trace level bitmask");
+
+MODULE_AUTHOR(DRIVER_AUTHOR);
+MODULE_DESCRIPTION(DRIVER_DESC);
+MODULE_LICENSE("GPL");
+MODULE_VERSION(DRIVER_VERSION);