Adding upstream version 6.1.76.upstream/6.1.76upstream

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 3033 insertions, 0 deletions

diff --git a/drivers/media/usb/uvc/uvc_driver.c b/drivers/media/usb/uvc/uvc_driver.c
new file mode 100644
index 000000000..191db831d
--- /dev/null
+++ b/drivers/media/usb/uvc/uvc_driver.c
@@ -0,0 +1,3033 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ *      uvc_driver.c  --  USB Video Class driver
+ *
+ *      Copyright (C) 2005-2010
+ *          Laurent Pinchart (laurent.pinchart@ideasonboard.com)
+ */
+
+#include <linux/atomic.h>
+#include <linux/bits.h>
+#include <linux/gpio/consumer.h>
+#include <linux/kernel.h>
+#include <linux/list.h>
+#include <linux/module.h>
+#include <linux/slab.h>
+#include <linux/usb.h>
+#include <linux/videodev2.h>
+#include <linux/vmalloc.h>
+#include <linux/wait.h>
+#include <asm/unaligned.h>
+
+#include <media/v4l2-common.h>
+#include <media/v4l2-ioctl.h>
+#include <media/v4l2-uvc.h>
+
+#include "uvcvideo.h"
+
+#define DRIVER_AUTHOR		"Laurent Pinchart " \
+				"<laurent.pinchart@ideasonboard.com>"
+#define DRIVER_DESC		"USB Video Class driver"
+
+unsigned int uvc_clock_param = CLOCK_MONOTONIC;
+unsigned int uvc_hw_timestamps_param;
+unsigned int uvc_no_drop_param;
+static unsigned int uvc_quirks_param = -1;
+unsigned int uvc_dbg_param;
+unsigned int uvc_timeout_param = UVC_CTRL_STREAMING_TIMEOUT;
+
+/* ------------------------------------------------------------------------
+ * 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 enum v4l2_colorspace uvc_colorspace(const u8 primaries)
+{
+	static const enum v4l2_colorspace colorprimaries[] = {
+		V4L2_COLORSPACE_SRGB,  /* Unspecified */
+		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 V4L2_COLORSPACE_SRGB;  /* Reserved */
+}
+
+static enum v4l2_xfer_func uvc_xfer_func(const u8 transfer_characteristics)
+{
+	/*
+	 * V4L2 does not currently have definitions for all possible values of
+	 * UVC transfer characteristics. If v4l2_xfer_func is extended with new
+	 * values, the mapping below should be updated.
+	 *
+	 * Substitutions are taken from the mapping given for
+	 * V4L2_XFER_FUNC_DEFAULT documented in videodev2.h.
+	 */
+	static const enum v4l2_xfer_func xfer_funcs[] = {
+		V4L2_XFER_FUNC_DEFAULT,    /* Unspecified */
+		V4L2_XFER_FUNC_709,
+		V4L2_XFER_FUNC_709,        /* Substitution for BT.470-2 M */
+		V4L2_XFER_FUNC_709,        /* Substitution for BT.470-2 B, G */
+		V4L2_XFER_FUNC_709,        /* Substitution for SMPTE 170M */
+		V4L2_XFER_FUNC_SMPTE240M,
+		V4L2_XFER_FUNC_NONE,
+		V4L2_XFER_FUNC_SRGB,
+	};
+
+	if (transfer_characteristics < ARRAY_SIZE(xfer_funcs))
+		return xfer_funcs[transfer_characteristics];
+
+	return V4L2_XFER_FUNC_DEFAULT;  /* Reserved */
+}
+
+static enum v4l2_ycbcr_encoding uvc_ycbcr_enc(const u8 matrix_coefficients)
+{
+	/*
+	 * V4L2 does not currently have definitions for all possible values of
+	 * UVC matrix coefficients. If v4l2_ycbcr_encoding is extended with new
+	 * values, the mapping below should be updated.
+	 *
+	 * Substitutions are taken from the mapping given for
+	 * V4L2_YCBCR_ENC_DEFAULT documented in videodev2.h.
+	 *
+	 * FCC is assumed to be close enough to 601.
+	 */
+	static const enum v4l2_ycbcr_encoding ycbcr_encs[] = {
+		V4L2_YCBCR_ENC_DEFAULT,  /* Unspecified */
+		V4L2_YCBCR_ENC_709,
+		V4L2_YCBCR_ENC_601,      /* Substitution for FCC */
+		V4L2_YCBCR_ENC_601,      /* Substitution for BT.470-2 B, G */
+		V4L2_YCBCR_ENC_601,
+		V4L2_YCBCR_ENC_SMPTE240M,
+	};
+
+	if (matrix_coefficients < ARRAY_SIZE(ycbcr_encs))
+		return ycbcr_encs[matrix_coefficients];
+
+	return V4L2_YCBCR_ENC_DEFAULT;  /* Reserved */
+}
+
+/* ------------------------------------------------------------------------
+ * Terminal and unit management
+ */
+
+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) {
+		for (i = 0; i < entity->bNrInPins; ++i)
+			if (entity->baSourceID[i] == id)
+				return entity;
+	}
+
+	return NULL;
+}
+
+static struct uvc_streaming *uvc_stream_by_id(struct uvc_device *dev, int id)
+{
+	struct uvc_streaming *stream;
+
+	list_for_each_entry(stream, &dev->streams, list) {
+		if (stream->header.bTerminalLink == id)
+			return stream;
+	}
+
+	return NULL;
+}
+
+/* ------------------------------------------------------------------------
+ * Streaming Object Management
+ */
+
+static void uvc_stream_delete(struct uvc_streaming *stream)
+{
+	if (stream->async_wq)
+		destroy_workqueue(stream->async_wq);
+
+	mutex_destroy(&stream->mutex);
+
+	usb_put_intf(stream->intf);
+
+	kfree(stream->format);
+	kfree(stream->header.bmaControls);
+	kfree(stream);
+}
+
+static struct uvc_streaming *uvc_stream_new(struct uvc_device *dev,
+					    struct usb_interface *intf)
+{
+	struct uvc_streaming *stream;
+
+	stream = kzalloc(sizeof(*stream), GFP_KERNEL);
+	if (stream == NULL)
+		return NULL;
+
+	mutex_init(&stream->mutex);
+
+	stream->dev = dev;
+	stream->intf = usb_get_intf(intf);
+	stream->intfnum = intf->cur_altsetting->desc.bInterfaceNumber;
+
+	/* Allocate a stream specific work queue for asynchronous tasks. */
+	stream->async_wq = alloc_workqueue("uvcvideo", WQ_UNBOUND | WQ_HIGHPRI,
+					   0);
+	if (!stream->async_wq) {
+		uvc_stream_delete(stream);
+		return NULL;
+	}
+
+	return stream;
+}
+
+/* ------------------------------------------------------------------------
+ * Descriptors parsing
+ */
+
+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 width_multiplier = 1;
+	unsigned int interval;
+	unsigned int i, n;
+	u8 ftype;
+
+	format->type = buffer[2];
+	format->index = buffer[3];
+
+	switch (buffer[2]) {
+	case UVC_VS_FORMAT_UNCOMPRESSED:
+	case UVC_VS_FORMAT_FRAME_BASED:
+		n = buffer[2] == UVC_VS_FORMAT_UNCOMPRESSED ? 27 : 28;
+		if (buflen < n) {
+			uvc_dbg(dev, 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) {
+			/*
+			 * Unknown video formats are not fatal errors, the
+			 * caller will skip this descriptor.
+			 */
+			dev_info(&streaming->intf->dev,
+				 "Unknown video format %pUl\n", &buffer[5]);
+			return 0;
+		}
+
+		format->fcc = fmtdesc->fcc;
+		format->bpp = buffer[21];
+
+		/*
+		 * Some devices report a format that doesn't match what they
+		 * really send.
+		 */
+		if (dev->quirks & UVC_QUIRK_FORCE_Y8) {
+			if (format->fcc == V4L2_PIX_FMT_YUYV) {
+				format->fcc = V4L2_PIX_FMT_GREY;
+				format->bpp = 8;
+				width_multiplier = 2;
+			}
+		}
+
+		/* Some devices report bpp that doesn't match the format. */
+		if (dev->quirks & UVC_QUIRK_FORCE_BPP) {
+			const struct v4l2_format_info *info =
+				v4l2_format_info(format->fcc);
+
+			if (info) {
+				unsigned int div = info->hdiv * info->vdiv;
+
+				n = info->bpp[0] * div;
+				for (i = 1; i < info->comp_planes; i++)
+					n += info->bpp[i];
+
+				format->bpp = DIV_ROUND_UP(8 * n, div);
+			}
+		}
+
+		if (buffer[2] == UVC_VS_FORMAT_UNCOMPRESSED) {
+			ftype = UVC_VS_FRAME_UNCOMPRESSED;
+		} else {
+			ftype = UVC_VS_FRAME_FRAME_BASED;
+			if (buffer[27])
+				format->flags = UVC_FMT_FLAG_COMPRESSED;
+		}
+		break;
+
+	case UVC_VS_FORMAT_MJPEG:
+		if (buflen < 11) {
+			uvc_dbg(dev, DESCR,
+				"device %d videostreaming interface %d FORMAT error\n",
+				dev->udev->devnum,
+				alts->desc.bInterfaceNumber);
+			return -EINVAL;
+		}
+
+		format->fcc = V4L2_PIX_FMT_MJPEG;
+		format->flags = UVC_FMT_FLAG_COMPRESSED;
+		format->bpp = 0;
+		ftype = UVC_VS_FRAME_MJPEG;
+		break;
+
+	case UVC_VS_FORMAT_DV:
+		if (buflen < 9) {
+			uvc_dbg(dev, DESCR,
+				"device %d videostreaming interface %d FORMAT error\n",
+				dev->udev->devnum,
+				alts->desc.bInterfaceNumber);
+			return -EINVAL;
+		}
+
+		if ((buffer[8] & 0x7f) > 2) {
+			uvc_dbg(dev, DESCR,
+				"device %d videostreaming interface %d: unknown DV format %u\n",
+				dev->udev->devnum,
+				alts->desc.bInterfaceNumber, buffer[8]);
+			return -EINVAL;
+		}
+
+		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 UVC_VS_FORMAT_MPEG2TS:
+	case UVC_VS_FORMAT_STREAM_BASED:
+		/* Not supported yet. */
+	default:
+		uvc_dbg(dev, DESCR,
+			"device %d videostreaming interface %d unsupported format %u\n",
+			dev->udev->devnum, alts->desc.bInterfaceNumber,
+			buffer[2]);
+		return -EINVAL;
+	}
+
+	uvc_dbg(dev, DESCR, "Found format %p4cc", &format->fcc);
+
+	buflen -= buffer[0];
+	buffer += buffer[0];
+
+	/*
+	 * Parse the frame descriptors. Only uncompressed, MJPEG and frame
+	 * based formats have frame descriptors.
+	 */
+	while (buflen > 2 && buffer[1] == USB_DT_CS_INTERFACE &&
+	       buffer[2] == ftype) {
+		frame = &format->frame[format->nframes];
+		if (ftype != UVC_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_dbg(dev, 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 = get_unaligned_le16(&buffer[5])
+			      * width_multiplier;
+		frame->wHeight = get_unaligned_le16(&buffer[7]);
+		frame->dwMinBitRate = get_unaligned_le32(&buffer[9]);
+		frame->dwMaxBitRate = get_unaligned_le32(&buffer[13]);
+		if (ftype != UVC_VS_FRAME_FRAME_BASED) {
+			frame->dwMaxVideoFrameBufferSize =
+				get_unaligned_le32(&buffer[17]);
+			frame->dwDefaultFrameInterval =
+				get_unaligned_le32(&buffer[21]);
+			frame->bFrameIntervalType = buffer[25];
+		} else {
+			frame->dwMaxVideoFrameBufferSize = 0;
+			frame->dwDefaultFrameInterval =
+				get_unaligned_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 to 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 that could happen.
+		 */
+		for (i = 0; i < n; ++i) {
+			interval = get_unaligned_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));
+
+		if (dev->quirks & UVC_QUIRK_RESTRICT_FRAME_RATE) {
+			frame->bFrameIntervalType = 1;
+			frame->dwFrameInterval[0] =
+				frame->dwDefaultFrameInterval;
+		}
+
+		uvc_dbg(dev, 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[1] == USB_DT_CS_INTERFACE &&
+	    buffer[2] == UVC_VS_STILL_IMAGE_FRAME) {
+		buflen -= buffer[0];
+		buffer += buffer[0];
+	}
+
+	if (buflen > 2 && buffer[1] == USB_DT_CS_INTERFACE &&
+	    buffer[2] == UVC_VS_COLORFORMAT) {
+		if (buflen < 6) {
+			uvc_dbg(dev, DESCR,
+				"device %d videostreaming interface %d COLORFORMAT error\n",
+				dev->udev->devnum,
+				alts->desc.bInterfaceNumber);
+			return -EINVAL;
+		}
+
+		format->colorspace = uvc_colorspace(buffer[3]);
+		format->xfer_func = uvc_xfer_func(buffer[4]);
+		format->ycbcr_enc = uvc_ycbcr_enc(buffer[5]);
+
+		buflen -= buffer[0];
+		buffer += buffer[0];
+	} else {
+		format->colorspace = V4L2_COLORSPACE_SRGB;
+	}
+
+	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
+		!= UVC_SC_VIDEOSTREAMING) {
+		uvc_dbg(dev, 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_dbg(dev, DESCR,
+			"device %d interface %d is already claimed\n",
+			dev->udev->devnum,
+			intf->altsetting[0].desc.bInterfaceNumber);
+		return -EINVAL;
+	}
+
+	streaming = uvc_stream_new(dev, intf);
+	if (streaming == NULL) {
+		usb_driver_release_interface(&uvc_driver.driver, intf);
+		return -ENOMEM;
+	}
+
+	/*
+	 * 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_dbg(dev, 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_dbg(dev, DESCR,
+			"no class-specific streaming interface descriptors found\n");
+		goto error;
+	}
+
+	/* Parse the header descriptor. */
+	switch (buffer[2]) {
+	case UVC_VS_OUTPUT_HEADER:
+		streaming->type = V4L2_BUF_TYPE_VIDEO_OUTPUT;
+		size = 9;
+		break;
+
+	case UVC_VS_INPUT_HEADER:
+		streaming->type = V4L2_BUF_TYPE_VIDEO_CAPTURE;
+		size = 13;
+		break;
+
+	default:
+		uvc_dbg(dev, DESCR,
+			"device %d videostreaming interface %d HEADER descriptor not found\n",
+			dev->udev->devnum, alts->desc.bInterfaceNumber);
+		goto error;
+	}
+
+	p = buflen >= 4 ? buffer[3] : 0;
+	n = buflen >= size ? buffer[size-1] : 0;
+
+	if (buflen < size + p*n) {
+		uvc_dbg(dev, DESCR,
+			"device %d videostreaming interface %d HEADER descriptor is invalid\n",
+			dev->udev->devnum, alts->desc.bInterfaceNumber);
+		goto error;
+	}
+
+	streaming->header.bNumFormats = p;
+	streaming->header.bEndpointAddress = buffer[6];
+	if (buffer[2] == UVC_VS_INPUT_HEADER) {
+		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];
+	} else {
+		streaming->header.bTerminalLink = buffer[7];
+	}
+	streaming->header.bControlSize = n;
+
+	streaming->header.bmaControls = kmemdup(&buffer[size], p * n,
+						GFP_KERNEL);
+	if (streaming->header.bmaControls == NULL) {
+		ret = -ENOMEM;
+		goto error;
+	}
+
+	buflen -= buffer[0];
+	buffer += buffer[0];
+
+	_buffer = buffer;
+	_buflen = buflen;
+
+	/* Count the format and frame descriptors. */
+	while (_buflen > 2 && _buffer[1] == USB_DT_CS_INTERFACE) {
+		switch (_buffer[2]) {
+		case UVC_VS_FORMAT_UNCOMPRESSED:
+		case UVC_VS_FORMAT_MJPEG:
+		case UVC_VS_FORMAT_FRAME_BASED:
+			nformats++;
+			break;
+
+		case UVC_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 UVC_VS_FORMAT_MPEG2TS:
+		case UVC_VS_FORMAT_STREAM_BASED:
+			uvc_dbg(dev, DESCR,
+				"device %d videostreaming interface %d FORMAT %u is not supported\n",
+				dev->udev->devnum,
+				alts->desc.bInterfaceNumber, _buffer[2]);
+			break;
+
+		case UVC_VS_FRAME_UNCOMPRESSED:
+		case UVC_VS_FRAME_MJPEG:
+			nframes++;
+			if (_buflen > 25)
+				nintervals += _buffer[25] ? _buffer[25] : 3;
+			break;
+
+		case UVC_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_dbg(dev, 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 = 0;
+
+	/* Parse the format descriptors. */
+	while (buflen > 2 && buffer[1] == USB_DT_CS_INTERFACE) {
+		switch (buffer[2]) {
+		case UVC_VS_FORMAT_UNCOMPRESSED:
+		case UVC_VS_FORMAT_MJPEG:
+		case UVC_VS_FORMAT_DV:
+		case UVC_VS_FORMAT_FRAME_BASED:
+			format->frame = frame;
+			ret = uvc_parse_format(dev, streaming, format,
+				&interval, buffer, buflen);
+			if (ret < 0)
+				goto error;
+			if (!ret)
+				break;
+
+			streaming->nformats++;
+			frame += format->nframes;
+			format++;
+
+			buflen -= ret;
+			buffer += ret;
+			continue;
+
+		default:
+			break;
+		}
+
+		buflen -= buffer[0];
+		buffer += buffer[0];
+	}
+
+	if (buflen)
+		uvc_dbg(dev, DESCR,
+			"device %d videostreaming interface %d has %u bytes of trailing descriptor garbage\n",
+			dev->udev->devnum, alts->desc.bInterfaceNumber, buflen);
+
+	/* 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 = uvc_endpoint_max_bpi(dev->udev, ep);
+		if (psize > streaming->maxpsize)
+			streaming->maxpsize = psize;
+	}
+
+	list_add_tail(&streaming->list, &dev->streams);
+	return 0;
+
+error:
+	usb_driver_release_interface(&uvc_driver.driver, intf);
+	uvc_stream_delete(streaming);
+	return ret;
+}
+
+static const u8 uvc_camera_guid[16] = UVC_GUID_UVC_CAMERA;
+static const u8 uvc_gpio_guid[16] = UVC_GUID_EXT_GPIO_CONTROLLER;
+static const u8 uvc_media_transport_input_guid[16] =
+	UVC_GUID_UVC_MEDIA_TRANSPORT_INPUT;
+static const u8 uvc_processing_guid[16] = UVC_GUID_UVC_PROCESSING;
+
+static struct uvc_entity *uvc_alloc_entity(u16 type, u16 id,
+		unsigned int num_pads, unsigned int extra_size)
+{
+	struct uvc_entity *entity;
+	unsigned int num_inputs;
+	unsigned int size;
+	unsigned int i;
+
+	extra_size = roundup(extra_size, sizeof(*entity->pads));
+	if (num_pads)
+		num_inputs = type & UVC_TERM_OUTPUT ? num_pads : num_pads - 1;
+	else
+		num_inputs = 0;
+	size = sizeof(*entity) + extra_size + sizeof(*entity->pads) * num_pads
+	     + num_inputs;
+	entity = kzalloc(size, GFP_KERNEL);
+	if (entity == NULL)
+		return NULL;
+
+	entity->id = id;
+	entity->type = type;
+
+	/*
+	 * Set the GUID for standard entity types. For extension units, the GUID
+	 * is initialized by the caller.
+	 */
+	switch (type) {
+	case UVC_EXT_GPIO_UNIT:
+		memcpy(entity->guid, uvc_gpio_guid, 16);
+		break;
+	case UVC_ITT_CAMERA:
+		memcpy(entity->guid, uvc_camera_guid, 16);
+		break;
+	case UVC_ITT_MEDIA_TRANSPORT_INPUT:
+		memcpy(entity->guid, uvc_media_transport_input_guid, 16);
+		break;
+	case UVC_VC_PROCESSING_UNIT:
+		memcpy(entity->guid, uvc_processing_guid, 16);
+		break;
+	}
+
+	entity->num_links = 0;
+	entity->num_pads = num_pads;
+	entity->pads = ((void *)(entity + 1)) + extra_size;
+
+	for (i = 0; i < num_inputs; ++i)
+		entity->pads[i].flags = MEDIA_PAD_FL_SINK;
+	if (!UVC_ENTITY_IS_OTERM(entity) && num_pads)
+		entity->pads[num_pads-1].flags = MEDIA_PAD_FL_SOURCE;
+
+	entity->bNrInPins = num_inputs;
+	entity->baSourceID = (u8 *)(&entity->pads[num_pads]);
+
+	return entity;
+}
+
+/* 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_dbg(dev, DESCR,
+				"device %d videocontrol interface %d EXTENSION_UNIT error\n",
+				udev->devnum, alts->desc.bInterfaceNumber);
+			break;
+		}
+
+		unit = uvc_alloc_entity(UVC_VC_EXTENSION_UNIT, buffer[3],
+					p + 1, 2*n);
+		if (unit == NULL)
+			return -ENOMEM;
+
+		memcpy(unit->guid, &buffer[4], 16);
+		unit->extension.bNumControls = buffer[20];
+		memcpy(unit->baSourceID, &buffer[22], p);
+		unit->extension.bControlSize = buffer[22+p];
+		unit->extension.bmControls = (u8 *)unit + sizeof(*unit);
+		unit->extension.bmControlsType = (u8 *)unit + sizeof(*unit)
+					       + 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)) < 0)
+			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 UVC_VC_HEADER:
+		n = buflen >= 12 ? buffer[11] : 0;
+
+		if (buflen < 12 + n) {
+			uvc_dbg(dev, DESCR,
+				"device %d videocontrol interface %d HEADER error\n",
+				udev->devnum, alts->desc.bInterfaceNumber);
+			return -EINVAL;
+		}
+
+		dev->uvc_version = get_unaligned_le16(&buffer[3]);
+		dev->clock_frequency = get_unaligned_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_dbg(dev, DESCR,
+					"device %d interface %d doesn't exists\n",
+					udev->devnum, i);
+				continue;
+			}
+
+			uvc_parse_streaming(dev, intf);
+		}
+		break;
+
+	case UVC_VC_INPUT_TERMINAL:
+		if (buflen < 8) {
+			uvc_dbg(dev, DESCR,
+				"device %d videocontrol interface %d INPUT_TERMINAL error\n",
+				udev->devnum, alts->desc.bInterfaceNumber);
+			return -EINVAL;
+		}
+
+		/*
+		 * Reject invalid terminal types that would cause issues:
+		 *
+		 * - The high byte must be non-zero, otherwise it would be
+		 *   confused with a unit.
+		 *
+		 * - Bit 15 must be 0, as we use it internally as a terminal
+		 *   direction flag.
+		 *
+		 * Other unknown types are accepted.
+		 */
+		type = get_unaligned_le16(&buffer[4]);
+		if ((type & 0x7f00) == 0 || (type & 0x8000) != 0) {
+			uvc_dbg(dev, 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 == UVC_ITT_CAMERA) {
+			n = buflen >= 15 ? buffer[14] : 0;
+			len = 15;
+
+		} else if (type == UVC_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_dbg(dev, DESCR,
+				"device %d videocontrol interface %d INPUT_TERMINAL error\n",
+				udev->devnum, alts->desc.bInterfaceNumber);
+			return -EINVAL;
+		}
+
+		term = uvc_alloc_entity(type | UVC_TERM_INPUT, buffer[3],
+					1, n + p);
+		if (term == NULL)
+			return -ENOMEM;
+
+		if (UVC_ENTITY_TYPE(term) == UVC_ITT_CAMERA) {
+			term->camera.bControlSize = n;
+			term->camera.bmControls = (u8 *)term + sizeof(*term);
+			term->camera.wObjectiveFocalLengthMin =
+				get_unaligned_le16(&buffer[8]);
+			term->camera.wObjectiveFocalLengthMax =
+				get_unaligned_le16(&buffer[10]);
+			term->camera.wOcularFocalLength =
+				get_unaligned_le16(&buffer[12]);
+			memcpy(term->camera.bmControls, &buffer[15], n);
+		} else if (UVC_ENTITY_TYPE(term) ==
+			   UVC_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)) < 0) {
+			if (UVC_ENTITY_TYPE(term) == UVC_ITT_CAMERA)
+				sprintf(term->name, "Camera %u", buffer[3]);
+			if (UVC_ENTITY_TYPE(term) == UVC_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 UVC_VC_OUTPUT_TERMINAL:
+		if (buflen < 9) {
+			uvc_dbg(dev, 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 = get_unaligned_le16(&buffer[4]);
+		if ((type & 0xff00) == 0) {
+			uvc_dbg(dev, 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 = uvc_alloc_entity(type | UVC_TERM_OUTPUT, buffer[3],
+					1, 0);
+		if (term == NULL)
+			return -ENOMEM;
+
+		memcpy(term->baSourceID, &buffer[7], 1);
+
+		if (buffer[8] == 0 ||
+		    usb_string(udev, buffer[8], term->name, sizeof(term->name)) < 0)
+			sprintf(term->name, "Output %u", buffer[3]);
+
+		list_add_tail(&term->list, &dev->entities);
+		break;
+
+	case UVC_VC_SELECTOR_UNIT:
+		p = buflen >= 5 ? buffer[4] : 0;
+
+		if (buflen < 5 || buflen < 6 + p) {
+			uvc_dbg(dev, DESCR,
+				"device %d videocontrol interface %d SELECTOR_UNIT error\n",
+				udev->devnum, alts->desc.bInterfaceNumber);
+			return -EINVAL;
+		}
+
+		unit = uvc_alloc_entity(buffer[2], buffer[3], p + 1, 0);
+		if (unit == NULL)
+			return -ENOMEM;
+
+		memcpy(unit->baSourceID, &buffer[5], p);
+
+		if (buffer[5+p] == 0 ||
+		    usb_string(udev, buffer[5+p], unit->name, sizeof(unit->name)) < 0)
+			sprintf(unit->name, "Selector %u", buffer[3]);
+
+		list_add_tail(&unit->list, &dev->entities);
+		break;
+
+	case UVC_VC_PROCESSING_UNIT:
+		n = buflen >= 8 ? buffer[7] : 0;
+		p = dev->uvc_version >= 0x0110 ? 10 : 9;
+
+		if (buflen < p + n) {
+			uvc_dbg(dev, DESCR,
+				"device %d videocontrol interface %d PROCESSING_UNIT error\n",
+				udev->devnum, alts->desc.bInterfaceNumber);
+			return -EINVAL;
+		}
+
+		unit = uvc_alloc_entity(buffer[2], buffer[3], 2, n);
+		if (unit == NULL)
+			return -ENOMEM;
+
+		memcpy(unit->baSourceID, &buffer[4], 1);
+		unit->processing.wMaxMultiplier =
+			get_unaligned_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)) < 0)
+			sprintf(unit->name, "Processing %u", buffer[3]);
+
+		list_add_tail(&unit->list, &dev->entities);
+		break;
+
+	case UVC_VC_EXTENSION_UNIT:
+		p = buflen >= 22 ? buffer[21] : 0;
+		n = buflen >= 24 + p ? buffer[22+p] : 0;
+
+		if (buflen < 24 + p + n) {
+			uvc_dbg(dev, DESCR,
+				"device %d videocontrol interface %d EXTENSION_UNIT error\n",
+				udev->devnum, alts->desc.bInterfaceNumber);
+			return -EINVAL;
+		}
+
+		unit = uvc_alloc_entity(buffer[2], buffer[3], p + 1, n);
+		if (unit == NULL)
+			return -ENOMEM;
+
+		memcpy(unit->guid, &buffer[4], 16);
+		unit->extension.bNumControls = buffer[20];
+		memcpy(unit->baSourceID, &buffer[22], p);
+		unit->extension.bControlSize = buffer[22+p];
+		unit->extension.bmControls = (u8 *)unit + sizeof(*unit);
+		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)) < 0)
+			sprintf(unit->name, "Extension %u", buffer[3]);
+
+		list_add_tail(&unit->list, &dev->entities);
+		break;
+
+	default:
+		uvc_dbg(dev, 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. Built-in iSight
+	 * webcams have an interrupt endpoint but spit proprietary data that
+	 * don't conform to the UVC status endpoint messages. Don't try to
+	 * handle the interrupt endpoint for those cameras.
+	 */
+	if (alts->desc.bNumEndpoints == 1 &&
+	    !(dev->quirks & UVC_QUIRK_BUILTIN_ISIGHT)) {
+		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_dbg(dev, DESCR,
+				"Found a Status endpoint (addr %02x)\n",
+				desc->bEndpointAddress);
+			dev->int_ep = ep;
+		}
+	}
+
+	return 0;
+}
+
+/* -----------------------------------------------------------------------------
+ * Privacy GPIO
+ */
+
+static void uvc_gpio_event(struct uvc_device *dev)
+{
+	struct uvc_entity *unit = dev->gpio_unit;
+	struct uvc_video_chain *chain;
+	u8 new_val;
+
+	if (!unit)
+		return;
+
+	new_val = gpiod_get_value_cansleep(unit->gpio.gpio_privacy);
+
+	/* GPIO entities are always on the first chain. */
+	chain = list_first_entry(&dev->chains, struct uvc_video_chain, list);
+	uvc_ctrl_status_event(chain, unit->controls, &new_val);
+}
+
+static int uvc_gpio_get_cur(struct uvc_device *dev, struct uvc_entity *entity,
+			    u8 cs, void *data, u16 size)
+{
+	if (cs != UVC_CT_PRIVACY_CONTROL || size < 1)
+		return -EINVAL;
+
+	*(u8 *)data = gpiod_get_value_cansleep(entity->gpio.gpio_privacy);
+
+	return 0;
+}
+
+static int uvc_gpio_get_info(struct uvc_device *dev, struct uvc_entity *entity,
+			     u8 cs, u8 *caps)
+{
+	if (cs != UVC_CT_PRIVACY_CONTROL)
+		return -EINVAL;
+
+	*caps = UVC_CONTROL_CAP_GET | UVC_CONTROL_CAP_AUTOUPDATE;
+	return 0;
+}
+
+static irqreturn_t uvc_gpio_irq(int irq, void *data)
+{
+	struct uvc_device *dev = data;
+
+	uvc_gpio_event(dev);
+	return IRQ_HANDLED;
+}
+
+static int uvc_gpio_parse(struct uvc_device *dev)
+{
+	struct uvc_entity *unit;
+	struct gpio_desc *gpio_privacy;
+	int irq;
+
+	gpio_privacy = devm_gpiod_get_optional(&dev->udev->dev, "privacy",
+					       GPIOD_IN);
+	if (IS_ERR_OR_NULL(gpio_privacy))
+		return PTR_ERR_OR_ZERO(gpio_privacy);
+
+	irq = gpiod_to_irq(gpio_privacy);
+	if (irq < 0) {
+		if (irq != EPROBE_DEFER)
+			dev_err(&dev->udev->dev,
+				"No IRQ for privacy GPIO (%d)\n", irq);
+		return irq;
+	}
+
+	unit = uvc_alloc_entity(UVC_EXT_GPIO_UNIT, UVC_EXT_GPIO_UNIT_ID, 0, 1);
+	if (!unit)
+		return -ENOMEM;
+
+	unit->gpio.gpio_privacy = gpio_privacy;
+	unit->gpio.irq = irq;
+	unit->gpio.bControlSize = 1;
+	unit->gpio.bmControls = (u8 *)unit + sizeof(*unit);
+	unit->gpio.bmControls[0] = 1;
+	unit->get_cur = uvc_gpio_get_cur;
+	unit->get_info = uvc_gpio_get_info;
+	strscpy(unit->name, "GPIO", sizeof(unit->name));
+
+	list_add_tail(&unit->list, &dev->entities);
+
+	dev->gpio_unit = unit;
+
+	return 0;
+}
+
+static int uvc_gpio_init_irq(struct uvc_device *dev)
+{
+	struct uvc_entity *unit = dev->gpio_unit;
+
+	if (!unit || unit->gpio.irq < 0)
+		return 0;
+
+	return devm_request_threaded_irq(&dev->udev->dev, unit->gpio.irq, NULL,
+					 uvc_gpio_irq,
+					 IRQF_ONESHOT | IRQF_TRIGGER_FALLING |
+					 IRQF_TRIGGER_RISING,
+					 "uvc_privacy_gpio", dev);
+}
+
+/* ------------------------------------------------------------------------
+ * UVC device scan
+ */
+
+/*
+ * Scan the UVC descriptors to locate a chain starting at an Output Terminal
+ * and containing the following units:
+ *
+ * - one or more Output Terminals (USB Streaming or Display)
+ * - zero or one Processing Unit
+ * - zero, one or more 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 or more Input Terminals (Camera, External or USB Streaming)
+ *
+ * The terminal and units must match on of the following structures:
+ *
+ * ITT_*(0) -> +---------+    +---------+    +---------+ -> TT_STREAMING(0)
+ * ...         | SU{0,1} | -> | PU{0,1} | -> | XU{0,n} |    ...
+ * ITT_*(n) -> +---------+    +---------+    +---------+ -> TT_STREAMING(n)
+ *
+ *                 +---------+    +---------+ -> OTT_*(0)
+ * TT_STREAMING -> | PU{0,1} | -> | XU{0,n} |    ...
+ *                 +---------+    +---------+ -> OTT_*(n)
+ *
+ * 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. Single-input Selector Units are ignored.
+ */
+static int uvc_scan_chain_entity(struct uvc_video_chain *chain,
+	struct uvc_entity *entity)
+{
+	switch (UVC_ENTITY_TYPE(entity)) {
+	case UVC_VC_EXTENSION_UNIT:
+		uvc_dbg_cont(PROBE, " <- XU %d", entity->id);
+
+		if (entity->bNrInPins != 1) {
+			uvc_dbg(chain->dev, DESCR,
+				"Extension unit %d has more than 1 input pin\n",
+				entity->id);
+			return -1;
+		}
+
+		break;
+
+	case UVC_VC_PROCESSING_UNIT:
+		uvc_dbg_cont(PROBE, " <- PU %d", entity->id);
+
+		if (chain->processing != NULL) {
+			uvc_dbg(chain->dev, DESCR,
+				"Found multiple Processing Units in chain\n");
+			return -1;
+		}
+
+		chain->processing = entity;
+		break;
+
+	case UVC_VC_SELECTOR_UNIT:
+		uvc_dbg_cont(PROBE, " <- SU %d", entity->id);
+
+		/* Single-input selector units are ignored. */
+		if (entity->bNrInPins == 1)
+			break;
+
+		if (chain->selector != NULL) {
+			uvc_dbg(chain->dev, DESCR,
+				"Found multiple Selector Units in chain\n");
+			return -1;
+		}
+
+		chain->selector = entity;
+		break;
+
+	case UVC_ITT_VENDOR_SPECIFIC:
+	case UVC_ITT_CAMERA:
+	case UVC_ITT_MEDIA_TRANSPORT_INPUT:
+		uvc_dbg_cont(PROBE, " <- IT %d\n", entity->id);
+
+		break;
+
+	case UVC_OTT_VENDOR_SPECIFIC:
+	case UVC_OTT_DISPLAY:
+	case UVC_OTT_MEDIA_TRANSPORT_OUTPUT:
+		uvc_dbg_cont(PROBE, " OT %d", entity->id);
+
+		break;
+
+	case UVC_TT_STREAMING:
+		if (UVC_ENTITY_IS_ITERM(entity))
+			uvc_dbg_cont(PROBE, " <- IT %d\n", entity->id);
+		else
+			uvc_dbg_cont(PROBE, " OT %d", entity->id);
+
+		break;
+
+	default:
+		uvc_dbg(chain->dev, DESCR,
+			"Unsupported entity type 0x%04x found in chain\n",
+			UVC_ENTITY_TYPE(entity));
+		return -1;
+	}
+
+	list_add_tail(&entity->chain, &chain->entities);
+	return 0;
+}
+
+static int uvc_scan_chain_forward(struct uvc_video_chain *chain,
+	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(chain->dev, entity->id,
+			forward);
+		if (forward == NULL)
+			break;
+		if (forward == prev)
+			continue;
+		if (forward->chain.next || forward->chain.prev) {
+			uvc_dbg(chain->dev, DESCR,
+				"Found reference to entity %d already in chain\n",
+				forward->id);
+			return -EINVAL;
+		}
+
+		switch (UVC_ENTITY_TYPE(forward)) {
+		case UVC_VC_EXTENSION_UNIT:
+			if (forward->bNrInPins != 1) {
+				uvc_dbg(chain->dev, DESCR,
+					"Extension unit %d has more than 1 input pin\n",
+					forward->id);
+				return -EINVAL;
+			}
+
+			/*
+			 * Some devices reference an output terminal as the
+			 * source of extension units. This is incorrect, as
+			 * output terminals only have an input pin, and thus
+			 * can't be connected to any entity in the forward
+			 * direction. The resulting topology would cause issues
+			 * when registering the media controller graph. To
+			 * avoid this problem, connect the extension unit to
+			 * the source of the output terminal instead.
+			 */
+			if (UVC_ENTITY_IS_OTERM(entity)) {
+				struct uvc_entity *source;
+
+				source = uvc_entity_by_id(chain->dev,
+							  entity->baSourceID[0]);
+				if (!source) {
+					uvc_dbg(chain->dev, DESCR,
+						"Can't connect extension unit %u in chain\n",
+						forward->id);
+					break;
+				}
+
+				forward->baSourceID[0] = source->id;
+			}
+
+			list_add_tail(&forward->chain, &chain->entities);
+			if (!found)
+				uvc_dbg_cont(PROBE, " (->");
+
+			uvc_dbg_cont(PROBE, " XU %d", forward->id);
+			found = 1;
+			break;
+
+		case UVC_OTT_VENDOR_SPECIFIC:
+		case UVC_OTT_DISPLAY:
+		case UVC_OTT_MEDIA_TRANSPORT_OUTPUT:
+		case UVC_TT_STREAMING:
+			if (UVC_ENTITY_IS_ITERM(forward)) {
+				uvc_dbg(chain->dev, DESCR,
+					"Unsupported input terminal %u\n",
+					forward->id);
+				return -EINVAL;
+			}
+
+			if (UVC_ENTITY_IS_OTERM(entity)) {
+				uvc_dbg(chain->dev, DESCR,
+					"Unsupported connection between output terminals %u and %u\n",
+					entity->id, forward->id);
+				break;
+			}
+
+			list_add_tail(&forward->chain, &chain->entities);
+			if (!found)
+				uvc_dbg_cont(PROBE, " (->");
+
+			uvc_dbg_cont(PROBE, " OT %d", forward->id);
+			found = 1;
+			break;
+		}
+	}
+	if (found)
+		uvc_dbg_cont(PROBE, ")");
+
+	return 0;
+}
+
+static int uvc_scan_chain_backward(struct uvc_video_chain *chain,
+	struct uvc_entity **_entity)
+{
+	struct uvc_entity *entity = *_entity;
+	struct uvc_entity *term;
+	int id = -EINVAL, i;
+
+	switch (UVC_ENTITY_TYPE(entity)) {
+	case UVC_VC_EXTENSION_UNIT:
+	case UVC_VC_PROCESSING_UNIT:
+		id = entity->baSourceID[0];
+		break;
+
+	case UVC_VC_SELECTOR_UNIT:
+		/* Single-input selector units are ignored. */
+		if (entity->bNrInPins == 1) {
+			id = entity->baSourceID[0];
+			break;
+		}
+
+		uvc_dbg_cont(PROBE, " <- IT");
+
+		chain->selector = entity;
+		for (i = 0; i < entity->bNrInPins; ++i) {
+			id = entity->baSourceID[i];
+			term = uvc_entity_by_id(chain->dev, id);
+			if (term == NULL || !UVC_ENTITY_IS_ITERM(term)) {
+				uvc_dbg(chain->dev, DESCR,
+					"Selector unit %d input %d isn't connected to an input terminal\n",
+					entity->id, i);
+				return -1;
+			}
+
+			if (term->chain.next || term->chain.prev) {
+				uvc_dbg(chain->dev, DESCR,
+					"Found reference to entity %d already in chain\n",
+					term->id);
+				return -EINVAL;
+			}
+
+			uvc_dbg_cont(PROBE, " %d", term->id);
+
+			list_add_tail(&term->chain, &chain->entities);
+			uvc_scan_chain_forward(chain, term, entity);
+		}
+
+		uvc_dbg_cont(PROBE, "\n");
+
+		id = 0;
+		break;
+
+	case UVC_ITT_VENDOR_SPECIFIC:
+	case UVC_ITT_CAMERA:
+	case UVC_ITT_MEDIA_TRANSPORT_INPUT:
+	case UVC_OTT_VENDOR_SPECIFIC:
+	case UVC_OTT_DISPLAY:
+	case UVC_OTT_MEDIA_TRANSPORT_OUTPUT:
+	case UVC_TT_STREAMING:
+		id = UVC_ENTITY_IS_OTERM(entity) ? entity->baSourceID[0] : 0;
+		break;
+	}
+
+	if (id <= 0) {
+		*_entity = NULL;
+		return id;
+	}
+
+	entity = uvc_entity_by_id(chain->dev, id);
+	if (entity == NULL) {
+		uvc_dbg(chain->dev, DESCR,
+			"Found reference to unknown entity %d\n", id);
+		return -EINVAL;
+	}
+
+	*_entity = entity;
+	return 0;
+}
+
+static int uvc_scan_chain(struct uvc_video_chain *chain,
+			  struct uvc_entity *term)
+{
+	struct uvc_entity *entity, *prev;
+
+	uvc_dbg(chain->dev, PROBE, "Scanning UVC chain:");
+
+	entity = term;
+	prev = NULL;
+
+	while (entity != NULL) {
+		/* Entity must not be part of an existing chain */
+		if (entity->chain.next || entity->chain.prev) {
+			uvc_dbg(chain->dev, DESCR,
+				"Found reference to entity %d already in chain\n",
+				entity->id);
+			return -EINVAL;
+		}
+
+		/* Process entity */
+		if (uvc_scan_chain_entity(chain, entity) < 0)
+			return -EINVAL;
+
+		/* Forward scan */
+		if (uvc_scan_chain_forward(chain, entity, prev) < 0)
+			return -EINVAL;
+
+		/* Backward scan */
+		prev = entity;
+		if (uvc_scan_chain_backward(chain, &entity) < 0)
+			return -EINVAL;
+	}
+
+	return 0;
+}
+
+static unsigned int uvc_print_terms(struct list_head *terms, u16 dir,
+		char *buffer)
+{
+	struct uvc_entity *term;
+	unsigned int nterms = 0;
+	char *p = buffer;
+
+	list_for_each_entry(term, terms, chain) {
+		if (!UVC_ENTITY_IS_TERM(term) ||
+		    UVC_TERM_DIRECTION(term) != dir)
+			continue;
+
+		if (nterms)
+			p += sprintf(p, ",");
+		if (++nterms >= 4) {
+			p += sprintf(p, "...");
+			break;
+		}
+		p += sprintf(p, "%u", term->id);
+	}
+
+	return p - buffer;
+}
+
+static const char *uvc_print_chain(struct uvc_video_chain *chain)
+{
+	static char buffer[43];
+	char *p = buffer;
+
+	p += uvc_print_terms(&chain->entities, UVC_TERM_INPUT, p);
+	p += sprintf(p, " -> ");
+	uvc_print_terms(&chain->entities, UVC_TERM_OUTPUT, p);
+
+	return buffer;
+}
+
+static struct uvc_video_chain *uvc_alloc_chain(struct uvc_device *dev)
+{
+	struct uvc_video_chain *chain;
+
+	chain = kzalloc(sizeof(*chain), GFP_KERNEL);
+	if (chain == NULL)
+		return NULL;
+
+	INIT_LIST_HEAD(&chain->entities);
+	mutex_init(&chain->ctrl_mutex);
+	chain->dev = dev;
+	v4l2_prio_init(&chain->prio);
+
+	return chain;
+}
+
+/*
+ * Fallback heuristic for devices that don't connect units and terminals in a
+ * valid chain.
+ *
+ * Some devices have invalid baSourceID references, causing uvc_scan_chain()
+ * to fail, but if we just take the entities we can find and put them together
+ * in the most sensible chain we can think of, turns out they do work anyway.
+ * Note: This heuristic assumes there is a single chain.
+ *
+ * At the time of writing, devices known to have such a broken chain are
+ *  - Acer Integrated Camera (5986:055a)
+ *  - Realtek rtl157a7 (0bda:57a7)
+ */
+static int uvc_scan_fallback(struct uvc_device *dev)
+{
+	struct uvc_video_chain *chain;
+	struct uvc_entity *iterm = NULL;
+	struct uvc_entity *oterm = NULL;
+	struct uvc_entity *entity;
+	struct uvc_entity *prev;
+
+	/*
+	 * Start by locating the input and output terminals. We only support
+	 * devices with exactly one of each for now.
+	 */
+	list_for_each_entry(entity, &dev->entities, list) {
+		if (UVC_ENTITY_IS_ITERM(entity)) {
+			if (iterm)
+				return -EINVAL;
+			iterm = entity;
+		}
+
+		if (UVC_ENTITY_IS_OTERM(entity)) {
+			if (oterm)
+				return -EINVAL;
+			oterm = entity;
+		}
+	}
+
+	if (iterm == NULL || oterm == NULL)
+		return -EINVAL;
+
+	/* Allocate the chain and fill it. */
+	chain = uvc_alloc_chain(dev);
+	if (chain == NULL)
+		return -ENOMEM;
+
+	if (uvc_scan_chain_entity(chain, oterm) < 0)
+		goto error;
+
+	prev = oterm;
+
+	/*
+	 * Add all Processing and Extension Units with two pads. The order
+	 * doesn't matter much, use reverse list traversal to connect units in
+	 * UVC descriptor order as we build the chain from output to input. This
+	 * leads to units appearing in the order meant by the manufacturer for
+	 * the cameras known to require this heuristic.
+	 */
+	list_for_each_entry_reverse(entity, &dev->entities, list) {
+		if (entity->type != UVC_VC_PROCESSING_UNIT &&
+		    entity->type != UVC_VC_EXTENSION_UNIT)
+			continue;
+
+		if (entity->num_pads != 2)
+			continue;
+
+		if (uvc_scan_chain_entity(chain, entity) < 0)
+			goto error;
+
+		prev->baSourceID[0] = entity->id;
+		prev = entity;
+	}
+
+	if (uvc_scan_chain_entity(chain, iterm) < 0)
+		goto error;
+
+	prev->baSourceID[0] = iterm->id;
+
+	list_add_tail(&chain->list, &dev->chains);
+
+	uvc_dbg(dev, PROBE, "Found a video chain by fallback heuristic (%s)\n",
+		uvc_print_chain(chain));
+
+	return 0;
+
+error:
+	kfree(chain);
+	return -EINVAL;
+}
+
+/*
+ * Scan the device for video chains and register video devices.
+ *
+ * Chains are scanned starting at their output terminals and walked backwards.
+ */
+static int uvc_scan_device(struct uvc_device *dev)
+{
+	struct uvc_video_chain *chain;
+	struct uvc_entity *term;
+
+	list_for_each_entry(term, &dev->entities, list) {
+		if (!UVC_ENTITY_IS_OTERM(term))
+			continue;
+
+		/*
+		 * If the terminal is already included in a chain, skip it.
+		 * This can happen for chains that have multiple output
+		 * terminals, where all output terminals beside the first one
+		 * will be inserted in the chain in forward scans.
+		 */
+		if (term->chain.next || term->chain.prev)
+			continue;
+
+		chain = uvc_alloc_chain(dev);
+		if (chain == NULL)
+			return -ENOMEM;
+
+		term->flags |= UVC_ENTITY_FLAG_DEFAULT;
+
+		if (uvc_scan_chain(chain, term) < 0) {
+			kfree(chain);
+			continue;
+		}
+
+		uvc_dbg(dev, PROBE, "Found a valid video chain (%s)\n",
+			uvc_print_chain(chain));
+
+		list_add_tail(&chain->list, &dev->chains);
+	}
+
+	if (list_empty(&dev->chains))
+		uvc_scan_fallback(dev);
+
+	if (list_empty(&dev->chains)) {
+		dev_info(&dev->udev->dev, "No valid video chain found.\n");
+		return -1;
+	}
+
+	/* Add GPIO entity to the first chain. */
+	if (dev->gpio_unit) {
+		chain = list_first_entry(&dev->chains,
+					 struct uvc_video_chain, list);
+		list_add_tail(&dev->gpio_unit->chain, &chain->entities);
+	}
+
+	return 0;
+}
+
+/* ------------------------------------------------------------------------
+ * Video device registration and unregistration
+ */
+
+/*
+ * Delete the UVC device.
+ *
+ * Called by the kernel when the last reference to the uvc_device structure
+ * is released.
+ *
+ * As this function is called after or during disconnect(), all URBs have
+ * already been cancelled by the USB core. There is no need to kill the
+ * interrupt URB manually.
+ */
+static void uvc_delete(struct kref *kref)
+{
+	struct uvc_device *dev = container_of(kref, struct uvc_device, ref);
+	struct list_head *p, *n;
+
+	uvc_status_cleanup(dev);
+	uvc_ctrl_cleanup_device(dev);
+
+	usb_put_intf(dev->intf);
+	usb_put_dev(dev->udev);
+
+#ifdef CONFIG_MEDIA_CONTROLLER
+	media_device_cleanup(&dev->mdev);
+#endif
+
+	list_for_each_safe(p, n, &dev->chains) {
+		struct uvc_video_chain *chain;
+		chain = list_entry(p, struct uvc_video_chain, list);
+		kfree(chain);
+	}
+
+	list_for_each_safe(p, n, &dev->entities) {
+		struct uvc_entity *entity;
+		entity = list_entry(p, struct uvc_entity, list);
+#ifdef CONFIG_MEDIA_CONTROLLER
+		uvc_mc_cleanup_entity(entity);
+#endif
+		kfree(entity);
+	}
+
+	list_for_each_safe(p, n, &dev->streams) {
+		struct uvc_streaming *streaming;
+		streaming = list_entry(p, struct uvc_streaming, list);
+		usb_driver_release_interface(&uvc_driver.driver,
+			streaming->intf);
+		uvc_stream_delete(streaming);
+	}
+
+	kfree(dev);
+}
+
+static void uvc_release(struct video_device *vdev)
+{
+	struct uvc_streaming *stream = video_get_drvdata(vdev);
+	struct uvc_device *dev = stream->dev;
+
+	kref_put(&dev->ref, uvc_delete);
+}
+
+/*
+ * Unregister the video devices.
+ */
+static void uvc_unregister_video(struct uvc_device *dev)
+{
+	struct uvc_streaming *stream;
+
+	list_for_each_entry(stream, &dev->streams, list) {
+		if (!video_is_registered(&stream->vdev))
+			continue;
+
+		video_unregister_device(&stream->vdev);
+		video_unregister_device(&stream->meta.vdev);
+
+		uvc_debugfs_cleanup_stream(stream);
+	}
+
+	uvc_status_unregister(dev);
+
+	if (dev->vdev.dev)
+		v4l2_device_unregister(&dev->vdev);
+#ifdef CONFIG_MEDIA_CONTROLLER
+	if (media_devnode_is_registered(dev->mdev.devnode))
+		media_device_unregister(&dev->mdev);
+#endif
+}
+
+int uvc_register_video_device(struct uvc_device *dev,
+			      struct uvc_streaming *stream,
+			      struct video_device *vdev,
+			      struct uvc_video_queue *queue,
+			      enum v4l2_buf_type type,
+			      const struct v4l2_file_operations *fops,
+			      const struct v4l2_ioctl_ops *ioctl_ops)
+{
+	int ret;
+
+	/* Initialize the video buffers queue. */
+	ret = uvc_queue_init(queue, type, !uvc_no_drop_param);
+	if (ret)
+		return ret;
+
+	/* Register the device with V4L. */
+
+	/*
+	 * 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->v4l2_dev = &dev->vdev;
+	vdev->fops = fops;
+	vdev->ioctl_ops = ioctl_ops;
+	vdev->release = uvc_release;
+	vdev->prio = &stream->chain->prio;
+	if (type == V4L2_BUF_TYPE_VIDEO_OUTPUT)
+		vdev->vfl_dir = VFL_DIR_TX;
+	else
+		vdev->vfl_dir = VFL_DIR_RX;
+
+	switch (type) {
+	case V4L2_BUF_TYPE_VIDEO_CAPTURE:
+	default:
+		vdev->device_caps = V4L2_CAP_VIDEO_CAPTURE | V4L2_CAP_STREAMING;
+		break;
+	case V4L2_BUF_TYPE_VIDEO_OUTPUT:
+		vdev->device_caps = V4L2_CAP_VIDEO_OUTPUT | V4L2_CAP_STREAMING;
+		break;
+	case V4L2_BUF_TYPE_META_CAPTURE:
+		vdev->device_caps = V4L2_CAP_META_CAPTURE | V4L2_CAP_STREAMING;
+		break;
+	}
+
+	strscpy(vdev->name, dev->name, sizeof(vdev->name));
+
+	/*
+	 * Set the driver data before calling video_register_device, otherwise
+	 * the file open() handler might race us.
+	 */
+	video_set_drvdata(vdev, stream);
+
+	ret = video_register_device(vdev, VFL_TYPE_VIDEO, -1);
+	if (ret < 0) {
+		dev_err(&stream->intf->dev,
+			"Failed to register %s device (%d).\n",
+			v4l2_type_names[type], ret);
+		return ret;
+	}
+
+	kref_get(&dev->ref);
+	return 0;
+}
+
+static int uvc_register_video(struct uvc_device *dev,
+		struct uvc_streaming *stream)
+{
+	int ret;
+
+	/* Initialize the streaming interface with default parameters. */
+	ret = uvc_video_init(stream);
+	if (ret < 0) {
+		dev_err(&stream->intf->dev,
+			"Failed to initialize the device (%d).\n", ret);
+		return ret;
+	}
+
+	if (stream->type == V4L2_BUF_TYPE_VIDEO_CAPTURE)
+		stream->chain->caps |= V4L2_CAP_VIDEO_CAPTURE
+			| V4L2_CAP_META_CAPTURE;
+	else
+		stream->chain->caps |= V4L2_CAP_VIDEO_OUTPUT;
+
+	uvc_debugfs_init_stream(stream);
+
+	/* Register the device with V4L. */
+	return uvc_register_video_device(dev, stream, &stream->vdev,
+					 &stream->queue, stream->type,
+					 &uvc_fops, &uvc_ioctl_ops);
+}
+
+/*
+ * Register all video devices in all chains.
+ */
+static int uvc_register_terms(struct uvc_device *dev,
+	struct uvc_video_chain *chain)
+{
+	struct uvc_streaming *stream;
+	struct uvc_entity *term;
+	int ret;
+
+	list_for_each_entry(term, &chain->entities, chain) {
+		if (UVC_ENTITY_TYPE(term) != UVC_TT_STREAMING)
+			continue;
+
+		stream = uvc_stream_by_id(dev, term->id);
+		if (stream == NULL) {
+			dev_info(&dev->udev->dev,
+				 "No streaming interface found for terminal %u.",
+				 term->id);
+			continue;
+		}
+
+		stream->chain = chain;
+		ret = uvc_register_video(dev, stream);
+		if (ret < 0)
+			return ret;
+
+		/*
+		 * Register a metadata node, but ignore a possible failure,
+		 * complete registration of video nodes anyway.
+		 */
+		uvc_meta_register(stream);
+
+		term->vdev = &stream->vdev;
+	}
+
+	return 0;
+}
+
+static int uvc_register_chains(struct uvc_device *dev)
+{
+	struct uvc_video_chain *chain;
+	int ret;
+
+	list_for_each_entry(chain, &dev->chains, list) {
+		ret = uvc_register_terms(dev, chain);
+		if (ret < 0)
+			return ret;
+
+#ifdef CONFIG_MEDIA_CONTROLLER
+		ret = uvc_mc_register_entities(chain);
+		if (ret < 0)
+			dev_info(&dev->udev->dev,
+				 "Failed to register entities (%d).\n", ret);
+#endif
+	}
+
+	return 0;
+}
+
+/* ------------------------------------------------------------------------
+ * USB probe, disconnect, suspend and resume
+ */
+
+static const struct uvc_device_info uvc_quirk_none = { 0 };
+
+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;
+	const struct uvc_device_info *info =
+		(const struct uvc_device_info *)id->driver_info;
+	int function;
+	int ret;
+
+	/* Allocate memory for the device and initialize it. */
+	dev = kzalloc(sizeof(*dev), GFP_KERNEL);
+	if (dev == NULL)
+		return -ENOMEM;
+
+	INIT_LIST_HEAD(&dev->entities);
+	INIT_LIST_HEAD(&dev->chains);
+	INIT_LIST_HEAD(&dev->streams);
+	kref_init(&dev->ref);
+	atomic_set(&dev->nmappings, 0);
+	mutex_init(&dev->lock);
+
+	dev->udev = usb_get_dev(udev);
+	dev->intf = usb_get_intf(intf);
+	dev->intfnum = intf->cur_altsetting->desc.bInterfaceNumber;
+	dev->info = info ? info : &uvc_quirk_none;
+	dev->quirks = uvc_quirks_param == -1
+		    ? dev->info->quirks : uvc_quirks_param;
+
+	if (id->idVendor && id->idProduct)
+		uvc_dbg(dev, PROBE, "Probing known UVC device %s (%04x:%04x)\n",
+			udev->devpath, id->idVendor, id->idProduct);
+	else
+		uvc_dbg(dev, PROBE, "Probing generic UVC device %s\n",
+			udev->devpath);
+
+	if (udev->product != NULL)
+		strscpy(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));
+
+	/*
+	 * Add iFunction or iInterface to names when available as additional
+	 * distinguishers between interfaces. iFunction is prioritized over
+	 * iInterface which matches Windows behavior at the point of writing.
+	 */
+	if (intf->intf_assoc && intf->intf_assoc->iFunction != 0)
+		function = intf->intf_assoc->iFunction;
+	else
+		function = intf->cur_altsetting->desc.iInterface;
+	if (function != 0) {
+		size_t len;
+
+		strlcat(dev->name, ": ", sizeof(dev->name));
+		len = strlen(dev->name);
+		usb_string(udev, function, dev->name + len,
+			   sizeof(dev->name) - len);
+	}
+
+	/* Initialize the media device. */
+#ifdef CONFIG_MEDIA_CONTROLLER
+	dev->mdev.dev = &intf->dev;
+	strscpy(dev->mdev.model, dev->name, sizeof(dev->mdev.model));
+	if (udev->serial)
+		strscpy(dev->mdev.serial, udev->serial,
+			sizeof(dev->mdev.serial));
+	usb_make_path(udev, dev->mdev.bus_info, sizeof(dev->mdev.bus_info));
+	dev->mdev.hw_revision = le16_to_cpu(udev->descriptor.bcdDevice);
+	media_device_init(&dev->mdev);
+
+	dev->vdev.mdev = &dev->mdev;
+#endif
+
+	/* Parse the Video Class control descriptor. */
+	if (uvc_parse_control(dev) < 0) {
+		uvc_dbg(dev, PROBE, "Unable to parse UVC descriptors\n");
+		goto error;
+	}
+
+	/* Parse the associated GPIOs. */
+	if (uvc_gpio_parse(dev) < 0) {
+		uvc_dbg(dev, PROBE, "Unable to parse UVC GPIOs\n");
+		goto error;
+	}
+
+	dev_info(&dev->udev->dev, "Found UVC %u.%02x 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 (dev->quirks != dev->info->quirks) {
+		dev_info(&dev->udev->dev,
+			 "Forcing device quirks to 0x%x by module parameter for testing purpose.\n",
+			 dev->quirks);
+		dev_info(&dev->udev->dev,
+			 "Please report required quirks to the linux-media mailing list.\n");
+	}
+
+	if (dev->info->uvc_version) {
+		dev->uvc_version = dev->info->uvc_version;
+		dev_info(&dev->udev->dev, "Forcing UVC version to %u.%02x\n",
+			 dev->uvc_version >> 8, dev->uvc_version & 0xff);
+	}
+
+	/* Register the V4L2 device. */
+	if (v4l2_device_register(&intf->dev, &dev->vdev) < 0)
+		goto error;
+
+	/* Scan the device for video chains. */
+	if (uvc_scan_device(dev) < 0)
+		goto error;
+
+	/* Initialize controls. */
+	if (uvc_ctrl_init_device(dev) < 0)
+		goto error;
+
+	/* Register video device nodes. */
+	if (uvc_register_chains(dev) < 0)
+		goto error;
+
+#ifdef CONFIG_MEDIA_CONTROLLER
+	/* Register the media device node */
+	if (media_device_register(&dev->mdev) < 0)
+		goto error;
+#endif
+	/* Save our data pointer in the interface data. */
+	usb_set_intfdata(intf, dev);
+
+	/* Initialize the interrupt URB. */
+	if ((ret = uvc_status_init(dev)) < 0) {
+		dev_info(&dev->udev->dev,
+			 "Unable to initialize the status endpoint (%d), status interrupt will not be supported.\n",
+			 ret);
+	}
+
+	ret = uvc_gpio_init_irq(dev);
+	if (ret < 0) {
+		dev_err(&dev->udev->dev,
+			"Unable to request privacy GPIO IRQ (%d)\n", ret);
+		goto error;
+	}
+
+	uvc_dbg(dev, PROBE, "UVC device initialized\n");
+	usb_enable_autosuspend(udev);
+	return 0;
+
+error:
+	uvc_unregister_video(dev);
+	kref_put(&dev->ref, 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 ==
+	    UVC_SC_VIDEOSTREAMING)
+		return;
+
+	uvc_unregister_video(dev);
+	kref_put(&dev->ref, uvc_delete);
+}
+
+static int uvc_suspend(struct usb_interface *intf, pm_message_t message)
+{
+	struct uvc_device *dev = usb_get_intfdata(intf);
+	struct uvc_streaming *stream;
+
+	uvc_dbg(dev, 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 ==
+	    UVC_SC_VIDEOCONTROL) {
+		mutex_lock(&dev->lock);
+		if (dev->users)
+			uvc_status_stop(dev);
+		mutex_unlock(&dev->lock);
+		return 0;
+	}
+
+	list_for_each_entry(stream, &dev->streams, list) {
+		if (stream->intf == intf)
+			return uvc_video_suspend(stream);
+	}
+
+	uvc_dbg(dev, SUSPEND,
+		"Suspend: video streaming USB interface mismatch\n");
+	return -EINVAL;
+}
+
+static int __uvc_resume(struct usb_interface *intf, int reset)
+{
+	struct uvc_device *dev = usb_get_intfdata(intf);
+	struct uvc_streaming *stream;
+	int ret = 0;
+
+	uvc_dbg(dev, SUSPEND, "Resuming interface %u\n",
+		intf->cur_altsetting->desc.bInterfaceNumber);
+
+	if (intf->cur_altsetting->desc.bInterfaceSubClass ==
+	    UVC_SC_VIDEOCONTROL) {
+		if (reset) {
+			ret = uvc_ctrl_restore_values(dev);
+			if (ret < 0)
+				return ret;
+		}
+
+		mutex_lock(&dev->lock);
+		if (dev->users)
+			ret = uvc_status_start(dev, GFP_NOIO);
+		mutex_unlock(&dev->lock);
+
+		return ret;
+	}
+
+	list_for_each_entry(stream, &dev->streams, list) {
+		if (stream->intf == intf) {
+			ret = uvc_video_resume(stream, reset);
+			if (ret < 0)
+				uvc_queue_streamoff(&stream->queue,
+						    stream->queue.queue.type);
+			return ret;
+		}
+	}
+
+	uvc_dbg(dev, SUSPEND,
+		"Resume: video streaming USB interface mismatch\n");
+	return -EINVAL;
+}
+
+static int uvc_resume(struct usb_interface *intf)
+{
+	return __uvc_resume(intf, 0);
+}
+
+static int uvc_reset_resume(struct usb_interface *intf)
+{
+	return __uvc_resume(intf, 1);
+}
+
+/* ------------------------------------------------------------------------
+ * Module parameters
+ */
+
+static int uvc_clock_param_get(char *buffer, const struct kernel_param *kp)
+{
+	if (uvc_clock_param == CLOCK_MONOTONIC)
+		return sprintf(buffer, "CLOCK_MONOTONIC");
+	else
+		return sprintf(buffer, "CLOCK_REALTIME");
+}
+
+static int uvc_clock_param_set(const char *val, const struct kernel_param *kp)
+{
+	if (strncasecmp(val, "clock_", strlen("clock_")) == 0)
+		val += strlen("clock_");
+
+	if (strcasecmp(val, "monotonic") == 0)
+		uvc_clock_param = CLOCK_MONOTONIC;
+	else if (strcasecmp(val, "realtime") == 0)
+		uvc_clock_param = CLOCK_REALTIME;
+	else
+		return -EINVAL;
+
+	return 0;
+}
+
+module_param_call(clock, uvc_clock_param_set, uvc_clock_param_get,
+		  &uvc_clock_param, S_IRUGO|S_IWUSR);
+MODULE_PARM_DESC(clock, "Video buffers timestamp clock");
+module_param_named(hwtimestamps, uvc_hw_timestamps_param, uint, S_IRUGO|S_IWUSR);
+MODULE_PARM_DESC(hwtimestamps, "Use hardware timestamps");
+module_param_named(nodrop, uvc_no_drop_param, uint, S_IRUGO|S_IWUSR);
+MODULE_PARM_DESC(nodrop, "Don't drop incomplete frames");
+module_param_named(quirks, uvc_quirks_param, uint, S_IRUGO|S_IWUSR);
+MODULE_PARM_DESC(quirks, "Forced device quirks");
+module_param_named(trace, uvc_dbg_param, uint, S_IRUGO|S_IWUSR);
+MODULE_PARM_DESC(trace, "Trace level bitmask");
+module_param_named(timeout, uvc_timeout_param, uint, S_IRUGO|S_IWUSR);
+MODULE_PARM_DESC(timeout, "Streaming control requests timeout");
+
+/* ------------------------------------------------------------------------
+ * Driver initialization and cleanup
+ */
+
+static const struct uvc_device_info uvc_ctrl_power_line_limited = {
+	.mappings = (const struct uvc_control_mapping *[]) {
+		&uvc_ctrl_power_line_mapping_limited,
+		NULL, /* Sentinel */
+	},
+};
+
+static const struct uvc_device_info uvc_quirk_probe_minmax = {
+	.quirks = UVC_QUIRK_PROBE_MINMAX,
+};
+
+static const struct uvc_device_info uvc_quirk_fix_bandwidth = {
+	.quirks = UVC_QUIRK_FIX_BANDWIDTH,
+};
+
+static const struct uvc_device_info uvc_quirk_probe_def = {
+	.quirks = UVC_QUIRK_PROBE_DEF,
+};
+
+static const struct uvc_device_info uvc_quirk_stream_no_fid = {
+	.quirks = UVC_QUIRK_STREAM_NO_FID,
+};
+
+static const struct uvc_device_info uvc_quirk_force_y8 = {
+	.quirks = UVC_QUIRK_FORCE_Y8,
+};
+
+#define UVC_INFO_QUIRK(q) (kernel_ulong_t)&(struct uvc_device_info){.quirks = q}
+#define UVC_INFO_META(m) (kernel_ulong_t)&(struct uvc_device_info) \
+	{.meta_format = m}
+
+/*
+ * 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 const struct usb_device_id uvc_ids[] = {
+	/* Quanta USB2.0 HD UVC Webcam */
+	{ .match_flags		= USB_DEVICE_ID_MATCH_DEVICE
+				| USB_DEVICE_ID_MATCH_INT_INFO,
+	  .idVendor		= 0x0408,
+	  .idProduct		= 0x3090,
+	  .bInterfaceClass	= USB_CLASS_VIDEO,
+	  .bInterfaceSubClass	= 1,
+	  .bInterfaceProtocol	= 0,
+	  .driver_info		= (kernel_ulong_t)&uvc_ctrl_power_line_limited },
+	/* Quanta USB2.0 HD UVC Webcam */
+	{ .match_flags		= USB_DEVICE_ID_MATCH_DEVICE
+				| USB_DEVICE_ID_MATCH_INT_INFO,
+	  .idVendor		= 0x0408,
+	  .idProduct		= 0x4030,
+	  .bInterfaceClass	= USB_CLASS_VIDEO,
+	  .bInterfaceSubClass	= 1,
+	  .bInterfaceProtocol	= 0,
+	  .driver_info		= (kernel_ulong_t)&uvc_ctrl_power_line_limited },
+	/* Quanta USB2.0 HD UVC Webcam */
+	{ .match_flags		= USB_DEVICE_ID_MATCH_DEVICE
+				| USB_DEVICE_ID_MATCH_INT_INFO,
+	  .idVendor		= 0x0408,
+	  .idProduct		= 0x4034,
+	  .bInterfaceClass	= USB_CLASS_VIDEO,
+	  .bInterfaceSubClass	= 1,
+	  .bInterfaceProtocol	= UVC_PC_PROTOCOL_15,
+	  .driver_info		= (kernel_ulong_t)&uvc_ctrl_power_line_limited },
+	/* LogiLink Wireless Webcam */
+	{ .match_flags		= USB_DEVICE_ID_MATCH_DEVICE
+				| USB_DEVICE_ID_MATCH_INT_INFO,
+	  .idVendor		= 0x0416,
+	  .idProduct		= 0xa91a,
+	  .bInterfaceClass	= USB_CLASS_VIDEO,
+	  .bInterfaceSubClass	= 1,
+	  .bInterfaceProtocol	= 0,
+	  .driver_info		= (kernel_ulong_t)&uvc_quirk_probe_minmax },
+	/* Genius eFace 2025 */
+	{ .match_flags		= USB_DEVICE_ID_MATCH_DEVICE
+				| USB_DEVICE_ID_MATCH_INT_INFO,
+	  .idVendor		= 0x0458,
+	  .idProduct		= 0x706e,
+	  .bInterfaceClass	= USB_CLASS_VIDEO,
+	  .bInterfaceSubClass	= 1,
+	  .bInterfaceProtocol	= 0,
+	  .driver_info		= (kernel_ulong_t)&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		= (kernel_ulong_t)&uvc_quirk_probe_minmax },
+	/* Microsoft Lifecam NX-3000 */
+	{ .match_flags		= USB_DEVICE_ID_MATCH_DEVICE
+				| USB_DEVICE_ID_MATCH_INT_INFO,
+	  .idVendor		= 0x045e,
+	  .idProduct		= 0x0721,
+	  .bInterfaceClass	= USB_CLASS_VIDEO,
+	  .bInterfaceSubClass	= 1,
+	  .bInterfaceProtocol	= 0,
+	  .driver_info		= (kernel_ulong_t)&uvc_quirk_probe_def },
+	/* 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		= (kernel_ulong_t)&uvc_quirk_probe_minmax },
+	/* Logitech, Webcam C910 */
+	{ .match_flags		= USB_DEVICE_ID_MATCH_DEVICE
+				| USB_DEVICE_ID_MATCH_INT_INFO,
+	  .idVendor		= 0x046d,
+	  .idProduct		= 0x0821,
+	  .bInterfaceClass	= USB_CLASS_VIDEO,
+	  .bInterfaceSubClass	= 1,
+	  .bInterfaceProtocol	= 0,
+	  .driver_info		= UVC_INFO_QUIRK(UVC_QUIRK_WAKE_AUTOSUSPEND)},
+	/* Logitech, Webcam B910 */
+	{ .match_flags		= USB_DEVICE_ID_MATCH_DEVICE
+				| USB_DEVICE_ID_MATCH_INT_INFO,
+	  .idVendor		= 0x046d,
+	  .idProduct		= 0x0823,
+	  .bInterfaceClass	= USB_CLASS_VIDEO,
+	  .bInterfaceSubClass	= 1,
+	  .bInterfaceProtocol	= 0,
+	  .driver_info		= UVC_INFO_QUIRK(UVC_QUIRK_WAKE_AUTOSUSPEND)},
+	/* 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 },
+	/* Logitech HD Pro Webcam C920 */
+	{ .match_flags		= USB_DEVICE_ID_MATCH_DEVICE
+				| USB_DEVICE_ID_MATCH_INT_INFO,
+	  .idVendor		= 0x046d,
+	  .idProduct		= 0x082d,
+	  .bInterfaceClass	= USB_CLASS_VIDEO,
+	  .bInterfaceSubClass	= 1,
+	  .bInterfaceProtocol	= 0,
+	  .driver_info		= UVC_INFO_QUIRK(UVC_QUIRK_RESTORE_CTRLS_ON_INIT) },
+	/* Chicony CNF7129 (Asus EEE 100HE) */
+	{ .match_flags		= USB_DEVICE_ID_MATCH_DEVICE
+				| USB_DEVICE_ID_MATCH_INT_INFO,
+	  .idVendor		= 0x04f2,
+	  .idProduct		= 0xb071,
+	  .bInterfaceClass	= USB_CLASS_VIDEO,
+	  .bInterfaceSubClass	= 1,
+	  .bInterfaceProtocol	= 0,
+	  .driver_info		= UVC_INFO_QUIRK(UVC_QUIRK_RESTRICT_FRAME_RATE) },
+	/* Chicony EasyCamera */
+	{ .match_flags		= USB_DEVICE_ID_MATCH_DEVICE
+				| USB_DEVICE_ID_MATCH_INT_INFO,
+	  .idVendor		= 0x04f2,
+	  .idProduct		= 0xb5eb,
+	  .bInterfaceClass	= USB_CLASS_VIDEO,
+	  .bInterfaceSubClass	= 1,
+	  .bInterfaceProtocol	= 0,
+	  .driver_info		= (kernel_ulong_t)&uvc_ctrl_power_line_limited },
+	/* Chicony EasyCamera */
+	{ .match_flags		= USB_DEVICE_ID_MATCH_DEVICE
+				| USB_DEVICE_ID_MATCH_INT_INFO,
+	  .idVendor		= 0x04f2,
+	  .idProduct		= 0xb6ba,
+	  .bInterfaceClass	= USB_CLASS_VIDEO,
+	  .bInterfaceSubClass	= 1,
+	  .bInterfaceProtocol	= 0,
+	  .driver_info		= (kernel_ulong_t)&uvc_ctrl_power_line_limited },
+	/* Chicony EasyCamera */
+	{ .match_flags		= USB_DEVICE_ID_MATCH_DEVICE
+				| USB_DEVICE_ID_MATCH_INT_INFO,
+	  .idVendor		= 0x04f2,
+	  .idProduct		= 0xb746,
+	  .bInterfaceClass	= USB_CLASS_VIDEO,
+	  .bInterfaceSubClass	= 1,
+	  .bInterfaceProtocol	= 0,
+	  .driver_info		= (kernel_ulong_t)&uvc_ctrl_power_line_limited },
+	/* Alcor Micro AU3820 (Future Boy PC USB Webcam) */
+	{ .match_flags		= USB_DEVICE_ID_MATCH_DEVICE
+				| USB_DEVICE_ID_MATCH_INT_INFO,
+	  .idVendor		= 0x058f,
+	  .idProduct		= 0x3820,
+	  .bInterfaceClass	= USB_CLASS_VIDEO,
+	  .bInterfaceSubClass	= 1,
+	  .bInterfaceProtocol	= 0,
+	  .driver_info		= (kernel_ulong_t)&uvc_quirk_probe_minmax },
+	/* Dell XPS m1530 */
+	{ .match_flags		= USB_DEVICE_ID_MATCH_DEVICE
+				| USB_DEVICE_ID_MATCH_INT_INFO,
+	  .idVendor		= 0x05a9,
+	  .idProduct		= 0x2640,
+	  .bInterfaceClass	= USB_CLASS_VIDEO,
+	  .bInterfaceSubClass	= 1,
+	  .bInterfaceProtocol	= 0,
+	  .driver_info		= (kernel_ulong_t)&uvc_quirk_probe_def },
+	/* Dell SP2008WFP Monitor */
+	{ .match_flags		= USB_DEVICE_ID_MATCH_DEVICE
+				| USB_DEVICE_ID_MATCH_INT_INFO,
+	  .idVendor		= 0x05a9,
+	  .idProduct		= 0x2641,
+	  .bInterfaceClass	= USB_CLASS_VIDEO,
+	  .bInterfaceSubClass	= 1,
+	  .bInterfaceProtocol	= 0,
+	  .driver_info		= (kernel_ulong_t)&uvc_quirk_probe_def },
+	/* Dell Alienware X51 */
+	{ .match_flags		= USB_DEVICE_ID_MATCH_DEVICE
+				| USB_DEVICE_ID_MATCH_INT_INFO,
+	  .idVendor		= 0x05a9,
+	  .idProduct		= 0x2643,
+	  .bInterfaceClass	= USB_CLASS_VIDEO,
+	  .bInterfaceSubClass	= 1,
+	  .bInterfaceProtocol	= 0,
+	  .driver_info		= (kernel_ulong_t)&uvc_quirk_probe_def },
+	/* Dell Studio Hybrid 140g (OmniVision webcam) */
+	{ .match_flags		= USB_DEVICE_ID_MATCH_DEVICE
+				| USB_DEVICE_ID_MATCH_INT_INFO,
+	  .idVendor		= 0x05a9,
+	  .idProduct		= 0x264a,
+	  .bInterfaceClass	= USB_CLASS_VIDEO,
+	  .bInterfaceSubClass	= 1,
+	  .bInterfaceProtocol	= 0,
+	  .driver_info		= (kernel_ulong_t)&uvc_quirk_probe_def },
+	/* Dell XPS M1330 (OmniVision OV7670 webcam) */
+	{ .match_flags		= USB_DEVICE_ID_MATCH_DEVICE
+				| USB_DEVICE_ID_MATCH_INT_INFO,
+	  .idVendor		= 0x05a9,
+	  .idProduct		= 0x7670,
+	  .bInterfaceClass	= USB_CLASS_VIDEO,
+	  .bInterfaceSubClass	= 1,
+	  .bInterfaceProtocol	= 0,
+	  .driver_info		= (kernel_ulong_t)&uvc_quirk_probe_def },
+	/* 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_INFO_QUIRK(UVC_QUIRK_PROBE_MINMAX
+					| UVC_QUIRK_BUILTIN_ISIGHT) },
+	/* Apple FaceTime HD Camera (Built-In) */
+	{ .match_flags		= USB_DEVICE_ID_MATCH_DEVICE
+				| USB_DEVICE_ID_MATCH_INT_INFO,
+	  .idVendor		= 0x05ac,
+	  .idProduct		= 0x8514,
+	  .bInterfaceClass	= USB_CLASS_VIDEO,
+	  .bInterfaceSubClass	= 1,
+	  .bInterfaceProtocol	= 0,
+	  .driver_info		= (kernel_ulong_t)&uvc_quirk_probe_def },
+	/* Apple Built-In iSight via iBridge */
+	{ .match_flags		= USB_DEVICE_ID_MATCH_DEVICE
+				| USB_DEVICE_ID_MATCH_INT_INFO,
+	  .idVendor		= 0x05ac,
+	  .idProduct		= 0x8600,
+	  .bInterfaceClass	= USB_CLASS_VIDEO,
+	  .bInterfaceSubClass	= 1,
+	  .bInterfaceProtocol	= 0,
+	  .driver_info		= (kernel_ulong_t)&uvc_quirk_probe_def },
+	/* Foxlink ("HP Webcam" on HP Mini 5103) */
+	{ .match_flags		= USB_DEVICE_ID_MATCH_DEVICE
+				| USB_DEVICE_ID_MATCH_INT_INFO,
+	  .idVendor		= 0x05c8,
+	  .idProduct		= 0x0403,
+	  .bInterfaceClass	= USB_CLASS_VIDEO,
+	  .bInterfaceSubClass	= 1,
+	  .bInterfaceProtocol	= 0,
+	  .driver_info		= (kernel_ulong_t)&uvc_quirk_fix_bandwidth },
+	/* 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		= (kernel_ulong_t)&uvc_quirk_stream_no_fid },
+	/* Hercules Classic Silver */
+	{ .match_flags		= USB_DEVICE_ID_MATCH_DEVICE
+				| USB_DEVICE_ID_MATCH_INT_INFO,
+	  .idVendor		= 0x06f8,
+	  .idProduct		= 0x300c,
+	  .bInterfaceClass	= USB_CLASS_VIDEO,
+	  .bInterfaceSubClass	= 1,
+	  .bInterfaceProtocol	= 0,
+	  .driver_info		= (kernel_ulong_t)&uvc_quirk_fix_bandwidth },
+	/* ViMicro Vega */
+	{ .match_flags		= USB_DEVICE_ID_MATCH_DEVICE
+				| USB_DEVICE_ID_MATCH_INT_INFO,
+	  .idVendor		= 0x0ac8,
+	  .idProduct		= 0x332d,
+	  .bInterfaceClass	= USB_CLASS_VIDEO,
+	  .bInterfaceSubClass	= 1,
+	  .bInterfaceProtocol	= 0,
+	  .driver_info		= (kernel_ulong_t)&uvc_quirk_fix_bandwidth },
+	/* ViMicro - Minoru3D */
+	{ .match_flags		= USB_DEVICE_ID_MATCH_DEVICE
+				| USB_DEVICE_ID_MATCH_INT_INFO,
+	  .idVendor		= 0x0ac8,
+	  .idProduct		= 0x3410,
+	  .bInterfaceClass	= USB_CLASS_VIDEO,
+	  .bInterfaceSubClass	= 1,
+	  .bInterfaceProtocol	= 0,
+	  .driver_info		= (kernel_ulong_t)&uvc_quirk_fix_bandwidth },
+	/* ViMicro Venus - Minoru3D */
+	{ .match_flags		= USB_DEVICE_ID_MATCH_DEVICE
+				| USB_DEVICE_ID_MATCH_INT_INFO,
+	  .idVendor		= 0x0ac8,
+	  .idProduct		= 0x3420,
+	  .bInterfaceClass	= USB_CLASS_VIDEO,
+	  .bInterfaceSubClass	= 1,
+	  .bInterfaceProtocol	= 0,
+	  .driver_info		= (kernel_ulong_t)&uvc_quirk_fix_bandwidth },
+	/* Ophir Optronics - SPCAM 620U */
+	{ .match_flags		= USB_DEVICE_ID_MATCH_DEVICE
+				| USB_DEVICE_ID_MATCH_INT_INFO,
+	  .idVendor		= 0x0bd3,
+	  .idProduct		= 0x0555,
+	  .bInterfaceClass	= USB_CLASS_VIDEO,
+	  .bInterfaceSubClass	= 1,
+	  .bInterfaceProtocol	= 0,
+	  .driver_info		= (kernel_ulong_t)&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_INFO_QUIRK(UVC_QUIRK_PROBE_MINMAX
+					| UVC_QUIRK_PROBE_DEF) },
+	/* IMC Networks (Medion Akoya) */
+	{ .match_flags		= USB_DEVICE_ID_MATCH_DEVICE
+				| USB_DEVICE_ID_MATCH_INT_INFO,
+	  .idVendor		= 0x13d3,
+	  .idProduct		= 0x5103,
+	  .bInterfaceClass	= USB_CLASS_VIDEO,
+	  .bInterfaceSubClass	= 1,
+	  .bInterfaceProtocol	= 0,
+	  .driver_info		= (kernel_ulong_t)&uvc_quirk_stream_no_fid },
+	/* JMicron USB2.0 XGA WebCam */
+	{ .match_flags		= USB_DEVICE_ID_MATCH_DEVICE
+				| USB_DEVICE_ID_MATCH_INT_INFO,
+	  .idVendor		= 0x152d,
+	  .idProduct		= 0x0310,
+	  .bInterfaceClass	= USB_CLASS_VIDEO,
+	  .bInterfaceSubClass	= 1,
+	  .bInterfaceProtocol	= 0,
+	  .driver_info		= (kernel_ulong_t)&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		= (kernel_ulong_t)&uvc_quirk_stream_no_fid },
+	/* Syntek (Samsung Q310) */
+	{ .match_flags		= USB_DEVICE_ID_MATCH_DEVICE
+				| USB_DEVICE_ID_MATCH_INT_INFO,
+	  .idVendor		= 0x174f,
+	  .idProduct		= 0x5931,
+	  .bInterfaceClass	= USB_CLASS_VIDEO,
+	  .bInterfaceSubClass	= 1,
+	  .bInterfaceProtocol	= 0,
+	  .driver_info		= (kernel_ulong_t)&uvc_quirk_stream_no_fid },
+	/* Syntek (Packard Bell EasyNote MX52 */
+	{ .match_flags		= USB_DEVICE_ID_MATCH_DEVICE
+				| USB_DEVICE_ID_MATCH_INT_INFO,
+	  .idVendor		= 0x174f,
+	  .idProduct		= 0x8a12,
+	  .bInterfaceClass	= USB_CLASS_VIDEO,
+	  .bInterfaceSubClass	= 1,
+	  .bInterfaceProtocol	= 0,
+	  .driver_info		= (kernel_ulong_t)&uvc_quirk_stream_no_fid },
+	/* Syntek (Asus F9SG) */
+	{ .match_flags		= USB_DEVICE_ID_MATCH_DEVICE
+				| USB_DEVICE_ID_MATCH_INT_INFO,
+	  .idVendor		= 0x174f,
+	  .idProduct		= 0x8a31,
+	  .bInterfaceClass	= USB_CLASS_VIDEO,
+	  .bInterfaceSubClass	= 1,
+	  .bInterfaceProtocol	= 0,
+	  .driver_info		= (kernel_ulong_t)&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		= (kernel_ulong_t)&uvc_quirk_stream_no_fid },
+	/* Syntek (JAOtech Smart Terminal) */
+	{ .match_flags		= USB_DEVICE_ID_MATCH_DEVICE
+				| USB_DEVICE_ID_MATCH_INT_INFO,
+	  .idVendor		= 0x174f,
+	  .idProduct		= 0x8a34,
+	  .bInterfaceClass	= USB_CLASS_VIDEO,
+	  .bInterfaceSubClass	= 1,
+	  .bInterfaceProtocol	= 0,
+	  .driver_info		= (kernel_ulong_t)&uvc_quirk_stream_no_fid },
+	/* Miricle 307K */
+	{ .match_flags		= USB_DEVICE_ID_MATCH_DEVICE
+				| USB_DEVICE_ID_MATCH_INT_INFO,
+	  .idVendor		= 0x17dc,
+	  .idProduct		= 0x0202,
+	  .bInterfaceClass	= USB_CLASS_VIDEO,
+	  .bInterfaceSubClass	= 1,
+	  .bInterfaceProtocol	= 0,
+	  .driver_info		= (kernel_ulong_t)&uvc_quirk_stream_no_fid },
+	/* Lenovo Thinkpad SL400/SL500 */
+	{ .match_flags		= USB_DEVICE_ID_MATCH_DEVICE
+				| USB_DEVICE_ID_MATCH_INT_INFO,
+	  .idVendor		= 0x17ef,
+	  .idProduct		= 0x480b,
+	  .bInterfaceClass	= USB_CLASS_VIDEO,
+	  .bInterfaceSubClass	= 1,
+	  .bInterfaceProtocol	= 0,
+	  .driver_info		= (kernel_ulong_t)&uvc_quirk_stream_no_fid },
+	/* Aveo Technology USB 2.0 Camera */
+	{ .match_flags		= USB_DEVICE_ID_MATCH_DEVICE
+				| USB_DEVICE_ID_MATCH_INT_INFO,
+	  .idVendor		= 0x1871,
+	  .idProduct		= 0x0306,
+	  .bInterfaceClass	= USB_CLASS_VIDEO,
+	  .bInterfaceSubClass	= 1,
+	  .bInterfaceProtocol	= 0,
+	  .driver_info		= UVC_INFO_QUIRK(UVC_QUIRK_PROBE_MINMAX
+					| UVC_QUIRK_PROBE_EXTRAFIELDS) },
+	/* Aveo Technology USB 2.0 Camera (Tasco USB Microscope) */
+	{ .match_flags		= USB_DEVICE_ID_MATCH_DEVICE
+				| USB_DEVICE_ID_MATCH_INT_INFO,
+	  .idVendor		= 0x1871,
+	  .idProduct		= 0x0516,
+	  .bInterfaceClass	= USB_CLASS_VENDOR_SPEC,
+	  .bInterfaceSubClass	= 1,
+	  .bInterfaceProtocol	= 0 },
+	/* 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_INFO_QUIRK(UVC_QUIRK_PROBE_EXTRAFIELDS) },
+	/* Manta MM-353 Plako */
+	{ .match_flags		= USB_DEVICE_ID_MATCH_DEVICE
+				| USB_DEVICE_ID_MATCH_INT_INFO,
+	  .idVendor		= 0x18ec,
+	  .idProduct		= 0x3188,
+	  .bInterfaceClass	= USB_CLASS_VIDEO,
+	  .bInterfaceSubClass	= 1,
+	  .bInterfaceProtocol	= 0,
+	  .driver_info		= (kernel_ulong_t)&uvc_quirk_probe_minmax },
+	/* FSC WebCam V30S */
+	{ .match_flags		= USB_DEVICE_ID_MATCH_DEVICE
+				| USB_DEVICE_ID_MATCH_INT_INFO,
+	  .idVendor		= 0x18ec,
+	  .idProduct		= 0x3288,
+	  .bInterfaceClass	= USB_CLASS_VIDEO,
+	  .bInterfaceSubClass	= 1,
+	  .bInterfaceProtocol	= 0,
+	  .driver_info		= (kernel_ulong_t)&uvc_quirk_probe_minmax },
+	/* Arkmicro unbranded */
+	{ .match_flags		= USB_DEVICE_ID_MATCH_DEVICE
+				| USB_DEVICE_ID_MATCH_INT_INFO,
+	  .idVendor		= 0x18ec,
+	  .idProduct		= 0x3290,
+	  .bInterfaceClass	= USB_CLASS_VIDEO,
+	  .bInterfaceSubClass	= 1,
+	  .bInterfaceProtocol	= 0,
+	  .driver_info		= (kernel_ulong_t)&uvc_quirk_probe_def },
+	/* The Imaging Source USB CCD cameras */
+	{ .match_flags		= USB_DEVICE_ID_MATCH_DEVICE
+				| USB_DEVICE_ID_MATCH_INT_INFO,
+	  .idVendor		= 0x199e,
+	  .idProduct		= 0x8102,
+	  .bInterfaceClass	= USB_CLASS_VENDOR_SPEC,
+	  .bInterfaceSubClass	= 1,
+	  .bInterfaceProtocol	= 0 },
+	/* 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_INFO_QUIRK(UVC_QUIRK_STATUS_INTERVAL) },
+	/* MSI StarCam 370i */
+	{ .match_flags		= USB_DEVICE_ID_MATCH_DEVICE
+				| USB_DEVICE_ID_MATCH_INT_INFO,
+	  .idVendor		= 0x1b3b,
+	  .idProduct		= 0x2951,
+	  .bInterfaceClass	= USB_CLASS_VIDEO,
+	  .bInterfaceSubClass	= 1,
+	  .bInterfaceProtocol	= 0,
+	  .driver_info		= (kernel_ulong_t)&uvc_quirk_probe_minmax },
+	/* Generalplus Technology Inc. 808 Camera */
+	{ .match_flags		= USB_DEVICE_ID_MATCH_DEVICE
+				| USB_DEVICE_ID_MATCH_INT_INFO,
+	  .idVendor		= 0x1b3f,
+	  .idProduct		= 0x2002,
+	  .bInterfaceClass	= USB_CLASS_VIDEO,
+	  .bInterfaceSubClass	= 1,
+	  .bInterfaceProtocol	= 0,
+	  .driver_info		= (kernel_ulong_t)&uvc_quirk_probe_minmax },
+	/* Shenzhen Aoni Electronic Co.,Ltd 2K FHD camera */
+	{ .match_flags		= USB_DEVICE_ID_MATCH_DEVICE
+				| USB_DEVICE_ID_MATCH_INT_INFO,
+	  .idVendor		= 0x1bcf,
+	  .idProduct		= 0x0b40,
+	  .bInterfaceClass	= USB_CLASS_VIDEO,
+	  .bInterfaceSubClass	= 1,
+	  .bInterfaceProtocol	= 0,
+	  .driver_info		= (kernel_ulong_t)&(const struct uvc_device_info){
+		.uvc_version = 0x010a,
+	  } },
+	/* 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_INFO_QUIRK(UVC_QUIRK_PROBE_MINMAX
+					| UVC_QUIRK_IGNORE_SELECTOR_UNIT) },
+	/* Oculus VR Positional Tracker DK2 */
+	{ .match_flags		= USB_DEVICE_ID_MATCH_DEVICE
+				| USB_DEVICE_ID_MATCH_INT_INFO,
+	  .idVendor		= 0x2833,
+	  .idProduct		= 0x0201,
+	  .bInterfaceClass	= USB_CLASS_VIDEO,
+	  .bInterfaceSubClass	= 1,
+	  .bInterfaceProtocol	= 0,
+	  .driver_info		= (kernel_ulong_t)&uvc_quirk_force_y8 },
+	/* Oculus VR Rift Sensor */
+	{ .match_flags		= USB_DEVICE_ID_MATCH_DEVICE
+				| USB_DEVICE_ID_MATCH_INT_INFO,
+	  .idVendor		= 0x2833,
+	  .idProduct		= 0x0211,
+	  .bInterfaceClass	= USB_CLASS_VENDOR_SPEC,
+	  .bInterfaceSubClass	= 1,
+	  .bInterfaceProtocol	= 0,
+	  .driver_info		= (kernel_ulong_t)&uvc_quirk_force_y8 },
+	/* GEO Semiconductor GC6500 */
+	{ .match_flags		= USB_DEVICE_ID_MATCH_DEVICE
+				| USB_DEVICE_ID_MATCH_INT_INFO,
+	  .idVendor		= 0x29fe,
+	  .idProduct		= 0x4d53,
+	  .bInterfaceClass	= USB_CLASS_VIDEO,
+	  .bInterfaceSubClass	= 1,
+	  .bInterfaceProtocol	= 0,
+	  .driver_info		= UVC_INFO_QUIRK(UVC_QUIRK_FORCE_BPP) },
+	/* Sonix Technology USB 2.0 Camera */
+	{ .match_flags		= USB_DEVICE_ID_MATCH_DEVICE
+				| USB_DEVICE_ID_MATCH_INT_INFO,
+	  .idVendor		= 0x3277,
+	  .idProduct		= 0x0072,
+	  .bInterfaceClass	= USB_CLASS_VIDEO,
+	  .bInterfaceSubClass	= 1,
+	  .bInterfaceProtocol	= 0,
+	  .driver_info		= (kernel_ulong_t)&uvc_ctrl_power_line_limited },
+	/* Acer EasyCamera */
+	{ .match_flags		= USB_DEVICE_ID_MATCH_DEVICE
+				| USB_DEVICE_ID_MATCH_INT_INFO,
+	  .idVendor		= 0x5986,
+	  .idProduct		= 0x1172,
+	  .bInterfaceClass	= USB_CLASS_VIDEO,
+	  .bInterfaceSubClass	= 1,
+	  .bInterfaceProtocol	= 0,
+	  .driver_info		= (kernel_ulong_t)&uvc_ctrl_power_line_limited },
+	/* Intel RealSense D4M */
+	{ .match_flags		= USB_DEVICE_ID_MATCH_DEVICE
+				| USB_DEVICE_ID_MATCH_INT_INFO,
+	  .idVendor		= 0x8086,
+	  .idProduct		= 0x0b03,
+	  .bInterfaceClass	= USB_CLASS_VIDEO,
+	  .bInterfaceSubClass	= 1,
+	  .bInterfaceProtocol	= 0,
+	  .driver_info		= UVC_INFO_META(V4L2_META_FMT_D4XX) },
+	/* Generic USB Video Class */
+	{ USB_INTERFACE_INFO(USB_CLASS_VIDEO, 1, UVC_PC_PROTOCOL_UNDEFINED) },
+	{ USB_INTERFACE_INFO(USB_CLASS_VIDEO, 1, UVC_PC_PROTOCOL_15) },
+	{}
+};
+
+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,
+		.reset_resume	= uvc_reset_resume,
+		.id_table	= uvc_ids,
+		.supports_autosuspend = 1,
+	},
+};
+
+static int __init uvc_init(void)
+{
+	int ret;
+
+	uvc_debugfs_init();
+
+	ret = usb_register(&uvc_driver.driver);
+	if (ret < 0) {
+		uvc_debugfs_cleanup();
+		return ret;
+	}
+
+	return 0;
+}
+
+static void __exit uvc_cleanup(void)
+{
+	usb_deregister(&uvc_driver.driver);
+	uvc_debugfs_cleanup();
+}
+
+module_init(uvc_init);
+module_exit(uvc_cleanup);
+
+MODULE_AUTHOR(DRIVER_AUTHOR);
+MODULE_DESCRIPTION(DRIVER_DESC);
+MODULE_LICENSE("GPL");
+MODULE_VERSION(DRIVER_VERSION);
+