V4L/DVB (8145a): USB Video Class driver

This driver supports video input devices compliant with the USB Video Class
specification. This means lots of currently manufactured webcams, and probably
most of the future ones.

Signed-off-by: Laurent Pinchart <laurent.pinchart@skynet.be>
Signed-off-by: Mauro Carvalho Chehab <mchehab@infradead.org>

1 files changed, 1105 insertions, 0 deletions

diff --git a/drivers/media/video/uvc/uvc_v4l2.c b/drivers/media/video/uvc/uvc_v4l2.c
new file mode 100644
index 00000000000..2e0a66575bb
--- /dev/null
+++ b/drivers/media/video/uvc/uvc_v4l2.c
@@ -0,0 +1,1105 @@
+/*
+ *      uvc_v4l2.c  --  USB Video Class driver - V4L2 API
+ *
+ *      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.
+ *
+ */
+
+#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/mm.h>
+#include <linux/wait.h>
+#include <asm/atomic.h>
+
+#include <media/v4l2-common.h>
+
+#include "uvcvideo.h"
+
+/* ------------------------------------------------------------------------
+ * V4L2 interface
+ */
+
+/*
+ * Mapping V4L2 controls to UVC controls can be straighforward if done well.
+ * Most of the UVC controls exist in V4L2, and can be mapped directly. Some
+ * must be grouped (for instance the Red Balance, Blue Balance and Do White
+ * Balance V4L2 controls use the White Balance Component UVC control) or
+ * otherwise translated. The approach we take here is to use a translation
+ * table for the controls which can be mapped directly, and handle the others
+ * manually.
+ */
+static int uvc_v4l2_query_menu(struct uvc_video_device *video,
+	struct v4l2_querymenu *query_menu)
+{
+	struct uvc_menu_info *menu_info;
+	struct uvc_control_mapping *mapping;
+	struct uvc_control *ctrl;
+
+	ctrl = uvc_find_control(video, query_menu->id, &mapping);
+	if (ctrl == NULL || mapping->v4l2_type != V4L2_CTRL_TYPE_MENU)
+		return -EINVAL;
+
+	if (query_menu->index >= mapping->menu_count)
+		return -EINVAL;
+
+	menu_info = &mapping->menu_info[query_menu->index];
+	strncpy(query_menu->name, menu_info->name, 32);
+	return 0;
+}
+
+/*
+ * Find the frame interval closest to the requested frame interval for the
+ * given frame format and size. This should be done by the device as part of
+ * the Video Probe and Commit negotiation, but some hardware don't implement
+ * that feature.
+ */
+static __u32 uvc_try_frame_interval(struct uvc_frame *frame, __u32 interval)
+{
+	unsigned int i;
+
+	if (frame->bFrameIntervalType) {
+		__u32 best = -1, dist;
+
+		for (i = 0; i < frame->bFrameIntervalType; ++i) {
+			dist = interval > frame->dwFrameInterval[i]
+			     ? interval - frame->dwFrameInterval[i]
+			     : frame->dwFrameInterval[i] - interval;
+
+			if (dist > best)
+				break;
+
+			best = dist;
+		}
+
+		interval = frame->dwFrameInterval[i-1];
+	} else {
+		const __u32 min = frame->dwFrameInterval[0];
+		const __u32 max = frame->dwFrameInterval[1];
+		const __u32 step = frame->dwFrameInterval[2];
+
+		interval = min + (interval - min + step/2) / step * step;
+		if (interval > max)
+			interval = max;
+	}
+
+	return interval;
+}
+
+static int uvc_v4l2_try_format(struct uvc_video_device *video,
+	struct v4l2_format *fmt, struct uvc_streaming_control *probe,
+	struct uvc_format **uvc_format, struct uvc_frame **uvc_frame)
+{
+	struct uvc_format *format = NULL;
+	struct uvc_frame *frame = NULL;
+	__u16 rw, rh;
+	unsigned int d, maxd;
+	unsigned int i;
+	__u32 interval;
+	int ret = 0;
+	__u8 *fcc;
+
+	if (fmt->type != V4L2_BUF_TYPE_VIDEO_CAPTURE)
+		return -EINVAL;
+
+	fcc = (__u8 *)&fmt->fmt.pix.pixelformat;
+	uvc_trace(UVC_TRACE_FORMAT, "Trying format 0x%08x (%c%c%c%c): %ux%u.\n",
+			fmt->fmt.pix.pixelformat,
+			fcc[0], fcc[1], fcc[2], fcc[3],
+			fmt->fmt.pix.width, fmt->fmt.pix.height);
+
+	/* Check if the hardware supports the requested format. */
+	for (i = 0; i < video->streaming->nformats; ++i) {
+		format = &video->streaming->format[i];
+		if (format->fcc == fmt->fmt.pix.pixelformat)
+			break;
+	}
+
+	if (format == NULL || format->fcc != fmt->fmt.pix.pixelformat) {
+		uvc_trace(UVC_TRACE_FORMAT, "Unsupported format 0x%08x.\n",
+				fmt->fmt.pix.pixelformat);
+		return -EINVAL;
+	}
+
+	/* Find the closest image size. The distance between image sizes is
+	 * the size in pixels of the non-overlapping regions between the
+	 * requested size and the frame-specified size.
+	 */
+	rw = fmt->fmt.pix.width;
+	rh = fmt->fmt.pix.height;
+	maxd = (unsigned int)-1;
+
+	for (i = 0; i < format->nframes; ++i) {
+		__u16 w = format->frame[i].wWidth;
+		__u16 h = format->frame[i].wHeight;
+
+		d = min(w, rw) * min(h, rh);
+		d = w*h + rw*rh - 2*d;
+		if (d < maxd) {
+			maxd = d;
+			frame = &format->frame[i];
+		}
+
+		if (maxd == 0)
+			break;
+	}
+
+	if (frame == NULL) {
+		uvc_trace(UVC_TRACE_FORMAT, "Unsupported size %ux%u.\n",
+				fmt->fmt.pix.width, fmt->fmt.pix.height);
+		return -EINVAL;
+	}
+
+	/* Use the default frame interval. */
+	interval = frame->dwDefaultFrameInterval;
+	uvc_trace(UVC_TRACE_FORMAT, "Using default frame interval %u.%u us "
+		"(%u.%u fps).\n", interval/10, interval%10, 10000000/interval,
+		(100000000/interval)%10);
+
+	/* Set the format index, frame index and frame interval. */
+	memset(probe, 0, sizeof *probe);
+	probe->bmHint = 1;	/* dwFrameInterval */
+	probe->bFormatIndex = format->index;
+	probe->bFrameIndex = frame->bFrameIndex;
+	probe->dwFrameInterval = uvc_try_frame_interval(frame, interval);
+	/* Some webcams stall the probe control set request when the
+	 * dwMaxVideoFrameSize field is set to zero. The UVC specification
+	 * clearly states that the field is read-only from the host, so this
+	 * is a webcam bug. Set dwMaxVideoFrameSize to the value reported by
+	 * the webcam to work around the problem.
+	 *
+	 * The workaround could probably be enabled for all webcams, so the
+	 * quirk can be removed if needed. It's currently useful to detect
+	 * webcam bugs and fix them before they hit the market (providing
+	 * developers test their webcams with the Linux driver as well as with
+	 * the Windows driver).
+	 */
+	if (video->dev->quirks & UVC_QUIRK_PROBE_EXTRAFIELDS)
+		probe->dwMaxVideoFrameSize =
+			video->streaming->ctrl.dwMaxVideoFrameSize;
+
+	/* Probe the device */
+	if ((ret = uvc_probe_video(video, probe)) < 0)
+		goto done;
+
+	fmt->fmt.pix.width = frame->wWidth;
+	fmt->fmt.pix.height = frame->wHeight;
+	fmt->fmt.pix.field = V4L2_FIELD_NONE;
+	fmt->fmt.pix.bytesperline = format->bpp * frame->wWidth / 8;
+	fmt->fmt.pix.sizeimage = probe->dwMaxVideoFrameSize;
+	fmt->fmt.pix.colorspace = format->colorspace;
+	fmt->fmt.pix.priv = 0;
+
+	if (uvc_format != NULL)
+		*uvc_format = format;
+	if (uvc_frame != NULL)
+		*uvc_frame = frame;
+
+done:
+	return ret;
+}
+
+static int uvc_v4l2_get_format(struct uvc_video_device *video,
+	struct v4l2_format *fmt)
+{
+	struct uvc_format *format = video->streaming->cur_format;
+	struct uvc_frame *frame = video->streaming->cur_frame;
+
+	if (fmt->type != V4L2_BUF_TYPE_VIDEO_CAPTURE)
+		return -EINVAL;
+
+	if (format == NULL || frame == NULL)
+		return -EINVAL;
+
+	fmt->fmt.pix.pixelformat = format->fcc;
+	fmt->fmt.pix.width = frame->wWidth;
+	fmt->fmt.pix.height = frame->wHeight;
+	fmt->fmt.pix.field = V4L2_FIELD_NONE;
+	fmt->fmt.pix.bytesperline = format->bpp * frame->wWidth / 8;
+	fmt->fmt.pix.sizeimage = video->streaming->ctrl.dwMaxVideoFrameSize;
+	fmt->fmt.pix.colorspace = format->colorspace;
+	fmt->fmt.pix.priv = 0;
+
+	return 0;
+}
+
+static int uvc_v4l2_set_format(struct uvc_video_device *video,
+	struct v4l2_format *fmt)
+{
+	struct uvc_streaming_control probe;
+	struct uvc_format *format;
+	struct uvc_frame *frame;
+	int ret;
+
+	if (fmt->type != V4L2_BUF_TYPE_VIDEO_CAPTURE)
+		return -EINVAL;
+
+	if (uvc_queue_streaming(&video->queue))
+		return -EBUSY;
+
+	ret = uvc_v4l2_try_format(video, fmt, &probe, &format, &frame);
+	if (ret < 0)
+		return ret;
+
+	if ((ret = uvc_set_video_ctrl(video, &probe, 0)) < 0)
+		return ret;
+
+	memcpy(&video->streaming->ctrl, &probe, sizeof probe);
+	video->streaming->cur_format = format;
+	video->streaming->cur_frame = frame;
+
+	return 0;
+}
+
+static int uvc_v4l2_get_streamparm(struct uvc_video_device *video,
+		struct v4l2_streamparm *parm)
+{
+	uint32_t numerator, denominator;
+
+	if (parm->type != V4L2_BUF_TYPE_VIDEO_CAPTURE)
+		return -EINVAL;
+
+	numerator = video->streaming->ctrl.dwFrameInterval;
+	denominator = 10000000;
+	uvc_simplify_fraction(&numerator, &denominator, 8, 333);
+
+	memset(parm, 0, sizeof *parm);
+	parm->type = V4L2_BUF_TYPE_VIDEO_CAPTURE;
+	parm->parm.capture.capability = V4L2_CAP_TIMEPERFRAME;
+	parm->parm.capture.capturemode = 0;
+	parm->parm.capture.timeperframe.numerator = numerator;
+	parm->parm.capture.timeperframe.denominator = denominator;
+	parm->parm.capture.extendedmode = 0;
+	parm->parm.capture.readbuffers = 0;
+
+	return 0;
+}
+
+static int uvc_v4l2_set_streamparm(struct uvc_video_device *video,
+		struct v4l2_streamparm *parm)
+{
+	struct uvc_frame *frame = video->streaming->cur_frame;
+	struct uvc_streaming_control probe;
+	uint32_t interval;
+	int ret;
+
+	if (parm->type != V4L2_BUF_TYPE_VIDEO_CAPTURE)
+		return -EINVAL;
+
+	if (uvc_queue_streaming(&video->queue))
+		return -EBUSY;
+
+	memcpy(&probe, &video->streaming->ctrl, sizeof probe);
+	interval = uvc_fraction_to_interval(
+			parm->parm.capture.timeperframe.numerator,
+			parm->parm.capture.timeperframe.denominator);
+
+	uvc_trace(UVC_TRACE_FORMAT, "Setting frame interval to %u/%u (%u).\n",
+			parm->parm.capture.timeperframe.numerator,
+			parm->parm.capture.timeperframe.denominator,
+			interval);
+	probe.dwFrameInterval = uvc_try_frame_interval(frame, interval);
+
+	/* Probe the device with the new settings. */
+	if ((ret = uvc_probe_video(video, &probe)) < 0)
+		return ret;
+
+	/* Commit the new settings. */
+	if ((ret = uvc_set_video_ctrl(video, &probe, 0)) < 0)
+		return ret;
+
+	memcpy(&video->streaming->ctrl, &probe, sizeof probe);
+
+	/* Return the actual frame period. */
+	parm->parm.capture.timeperframe.numerator = probe.dwFrameInterval;
+	parm->parm.capture.timeperframe.denominator = 10000000;
+	uvc_simplify_fraction(&parm->parm.capture.timeperframe.numerator,
+				&parm->parm.capture.timeperframe.denominator,
+				8, 333);
+
+	return 0;
+}
+
+/* ------------------------------------------------------------------------
+ * Privilege management
+ */
+
+/*
+ * Privilege management is the multiple-open implementation basis. The current
+ * implementation is completely transparent for the end-user and doesn't
+ * require explicit use of the VIDIOC_G_PRIORITY and VIDIOC_S_PRIORITY ioctls.
+ * Those ioctls enable finer control on the device (by making possible for a
+ * user to request exclusive access to a device), but are not mature yet.
+ * Switching to the V4L2 priority mechanism might be considered in the future
+ * if this situation changes.
+ *
+ * Each open instance of a UVC device can either be in a privileged or
+ * unprivileged state. Only a single instance can be in a privileged state at
+ * a given time. Trying to perform an operation which requires privileges will
+ * automatically acquire the required privileges if possible, or return -EBUSY
+ * otherwise. Privileges are dismissed when closing the instance.
+ *
+ * Operations which require privileges are:
+ *
+ * - VIDIOC_S_INPUT
+ * - VIDIOC_S_PARM
+ * - VIDIOC_S_FMT
+ * - VIDIOC_TRY_FMT
+ * - VIDIOC_REQBUFS
+ */
+static int uvc_acquire_privileges(struct uvc_fh *handle)
+{
+	int ret = 0;
+
+	/* Always succeed if the handle is already privileged. */
+	if (handle->state == UVC_HANDLE_ACTIVE)
+		return 0;
+
+	/* Check if the device already has a privileged handle. */
+	mutex_lock(&uvc_driver.open_mutex);
+	if (atomic_inc_return(&handle->device->active) != 1) {
+		atomic_dec(&handle->device->active);
+		ret = -EBUSY;
+		goto done;
+	}
+
+	handle->state = UVC_HANDLE_ACTIVE;
+
+done:
+	mutex_unlock(&uvc_driver.open_mutex);
+	return ret;
+}
+
+static void uvc_dismiss_privileges(struct uvc_fh *handle)
+{
+	if (handle->state == UVC_HANDLE_ACTIVE)
+		atomic_dec(&handle->device->active);
+
+	handle->state = UVC_HANDLE_PASSIVE;
+}
+
+static int uvc_has_privileges(struct uvc_fh *handle)
+{
+	return handle->state == UVC_HANDLE_ACTIVE;
+}
+
+/* ------------------------------------------------------------------------
+ * V4L2 file operations
+ */
+
+static int uvc_v4l2_open(struct inode *inode, struct file *file)
+{
+	struct video_device *vdev;
+	struct uvc_video_device *video;
+	struct uvc_fh *handle;
+	int ret = 0;
+
+	uvc_trace(UVC_TRACE_CALLS, "uvc_v4l2_open\n");
+	mutex_lock(&uvc_driver.open_mutex);
+	vdev = video_devdata(file);
+	video = video_get_drvdata(vdev);
+
+	if (video->dev->state & UVC_DEV_DISCONNECTED) {
+		ret = -ENODEV;
+		goto done;
+	}
+
+	ret = usb_autopm_get_interface(video->dev->intf);
+	if (ret < 0)
+		goto done;
+
+	/* Create the device handle. */
+	handle = kzalloc(sizeof *handle, GFP_KERNEL);
+	if (handle == NULL) {
+		usb_autopm_put_interface(video->dev->intf);
+		ret = -ENOMEM;
+		goto done;
+	}
+
+	handle->device = video;
+	handle->state = UVC_HANDLE_PASSIVE;
+	file->private_data = handle;
+
+	kref_get(&video->dev->kref);
+
+done:
+	mutex_unlock(&uvc_driver.open_mutex);
+	return ret;
+}
+
+static int uvc_v4l2_release(struct inode *inode, struct file *file)
+{
+	struct video_device *vdev = video_devdata(file);
+	struct uvc_video_device *video = video_get_drvdata(vdev);
+	struct uvc_fh *handle = (struct uvc_fh *)file->private_data;
+
+	uvc_trace(UVC_TRACE_CALLS, "uvc_v4l2_release\n");
+
+	/* Only free resources if this is a privileged handle. */
+	if (uvc_has_privileges(handle)) {
+		uvc_video_enable(video, 0);
+
+		mutex_lock(&video->queue.mutex);
+		if (uvc_free_buffers(&video->queue) < 0)
+			uvc_printk(KERN_ERR, "uvc_v4l2_release: Unable to "
+					"free buffers.\n");
+		mutex_unlock(&video->queue.mutex);
+	}
+
+	/* Release the file handle. */
+	uvc_dismiss_privileges(handle);
+	kfree(handle);
+	file->private_data = NULL;
+
+	usb_autopm_put_interface(video->dev->intf);
+	kref_put(&video->dev->kref, uvc_delete);
+	return 0;
+}
+
+static int uvc_v4l2_do_ioctl(struct inode *inode, struct file *file,
+		     unsigned int cmd, void *arg)
+{
+	struct video_device *vdev = video_devdata(file);
+	struct uvc_video_device *video = video_get_drvdata(vdev);
+	struct uvc_fh *handle = (struct uvc_fh *)file->private_data;
+	int ret = 0;
+
+	if (uvc_trace_param & UVC_TRACE_IOCTL)
+		v4l_printk_ioctl(cmd);
+
+	switch (cmd) {
+	/* Query capabilities */
+	case VIDIOC_QUERYCAP:
+	{
+		struct v4l2_capability *cap = arg;
+
+		memset(cap, 0, sizeof *cap);
+		strncpy(cap->driver, "uvcvideo", sizeof cap->driver);
+		strncpy(cap->card, vdev->name, 32);
+		strncpy(cap->bus_info, video->dev->udev->bus->bus_name,
+			sizeof cap->bus_info);
+		cap->version = DRIVER_VERSION_NUMBER;
+		cap->capabilities = V4L2_CAP_VIDEO_CAPTURE
+				  | V4L2_CAP_STREAMING;
+		break;
+	}
+
+	/* Get, Set & Query control */
+	case VIDIOC_QUERYCTRL:
+		return uvc_query_v4l2_ctrl(video, arg);
+
+	case VIDIOC_G_CTRL:
+	{
+		struct v4l2_control *ctrl = arg;
+		struct v4l2_ext_control xctrl;
+
+		memset(&xctrl, 0, sizeof xctrl);
+		xctrl.id = ctrl->id;
+
+		uvc_ctrl_begin(video);
+		ret = uvc_ctrl_get(video, &xctrl);
+		uvc_ctrl_rollback(video);
+		if (ret >= 0)
+			ctrl->value = xctrl.value;
+		break;
+	}
+
+	case VIDIOC_S_CTRL:
+	{
+		struct v4l2_control *ctrl = arg;
+		struct v4l2_ext_control xctrl;
+
+		memset(&xctrl, 0, sizeof xctrl);
+		xctrl.id = ctrl->id;
+		xctrl.value = ctrl->value;
+
+		uvc_ctrl_begin(video);
+		ret = uvc_ctrl_set(video, &xctrl);
+		if (ret < 0) {
+			uvc_ctrl_rollback(video);
+			return ret;
+		}
+		ret = uvc_ctrl_commit(video);
+		break;
+	}
+
+	case VIDIOC_QUERYMENU:
+		return uvc_v4l2_query_menu(video, arg);
+
+	case VIDIOC_G_EXT_CTRLS:
+	{
+		struct v4l2_ext_controls *ctrls = arg;
+		struct v4l2_ext_control *ctrl = ctrls->controls;
+		unsigned int i;
+
+		uvc_ctrl_begin(video);
+		for (i = 0; i < ctrls->count; ++ctrl, ++i) {
+			ret = uvc_ctrl_get(video, ctrl);
+			if (ret < 0) {
+				uvc_ctrl_rollback(video);
+				ctrls->error_idx = i;
+				return ret;
+			}
+		}
+		ctrls->error_idx = 0;
+		ret = uvc_ctrl_rollback(video);
+		break;
+	}
+
+	case VIDIOC_S_EXT_CTRLS:
+	case VIDIOC_TRY_EXT_CTRLS:
+	{
+		struct v4l2_ext_controls *ctrls = arg;
+		struct v4l2_ext_control *ctrl = ctrls->controls;
+		unsigned int i;
+
+		ret = uvc_ctrl_begin(video);
+		if (ret < 0)
+			return ret;
+
+		for (i = 0; i < ctrls->count; ++ctrl, ++i) {
+			ret = uvc_ctrl_set(video, ctrl);
+			if (ret < 0) {
+				uvc_ctrl_rollback(video);
+				ctrls->error_idx = i;
+				return ret;
+			}
+		}
+
+		ctrls->error_idx = 0;
+
+		if (cmd == VIDIOC_S_EXT_CTRLS)
+			ret = uvc_ctrl_commit(video);
+		else
+			ret = uvc_ctrl_rollback(video);
+		break;
+	}
+
+	/* Get, Set & Enum input */
+	case VIDIOC_ENUMINPUT:
+	{
+		const struct uvc_entity *selector = video->selector;
+		struct v4l2_input *input = arg;
+		struct uvc_entity *iterm = NULL;
+		u32 index = input->index;
+		int pin = 0;
+
+		if (selector == NULL ||
+		    (video->dev->quirks & UVC_QUIRK_IGNORE_SELECTOR_UNIT)) {
+			if (index != 0)
+				return -EINVAL;
+			iterm = list_first_entry(&video->iterms,
+					struct uvc_entity, chain);
+			pin = iterm->id;
+		} else if (pin < selector->selector.bNrInPins) {
+			pin = selector->selector.baSourceID[index];
+			list_for_each_entry(iterm, video->iterms.next, chain) {
+				if (iterm->id == pin)
+					break;
+			}
+		}
+
+		if (iterm == NULL || iterm->id != pin)
+			return -EINVAL;
+
+		memset(input, 0, sizeof *input);
+		input->index = index;
+		strncpy(input->name, iterm->name, sizeof input->name);
+		if (UVC_ENTITY_TYPE(iterm) == ITT_CAMERA)
+			input->type = V4L2_INPUT_TYPE_CAMERA;
+		break;
+	}
+
+	case VIDIOC_G_INPUT:
+	{
+		u8 input;
+
+		if (video->selector == NULL ||
+		    (video->dev->quirks & UVC_QUIRK_IGNORE_SELECTOR_UNIT)) {
+			*(int *)arg = 0;
+			break;
+		}
+
+		ret = uvc_query_ctrl(video->dev, GET_CUR, video->selector->id,
+			video->dev->intfnum, SU_INPUT_SELECT_CONTROL,
+			&input, 1);
+		if (ret < 0)
+			return ret;
+
+		*(int *)arg = input - 1;
+		break;
+	}
+
+	case VIDIOC_S_INPUT:
+	{
+		u8 input = *(u32 *)arg + 1;
+
+		if ((ret = uvc_acquire_privileges(handle)) < 0)
+			return ret;
+
+		if (video->selector == NULL ||
+		    (video->dev->quirks & UVC_QUIRK_IGNORE_SELECTOR_UNIT)) {
+			if (input != 1)
+				return -EINVAL;
+			break;
+		}
+
+		if (input > video->selector->selector.bNrInPins)
+			return -EINVAL;
+
+		return uvc_query_ctrl(video->dev, SET_CUR, video->selector->id,
+			video->dev->intfnum, SU_INPUT_SELECT_CONTROL,
+			&input, 1);
+	}
+
+	/* Try, Get, Set & Enum format */
+	case VIDIOC_ENUM_FMT:
+	{
+		struct v4l2_fmtdesc *fmt = arg;
+		struct uvc_format *format;
+
+		if (fmt->type != V4L2_BUF_TYPE_VIDEO_CAPTURE ||
+		    fmt->index >= video->streaming->nformats)
+			return -EINVAL;
+
+		format = &video->streaming->format[fmt->index];
+		fmt->flags = 0;
+		if (format->flags & UVC_FMT_FLAG_COMPRESSED)
+			fmt->flags |= V4L2_FMT_FLAG_COMPRESSED;
+		strncpy(fmt->description, format->name,
+			sizeof fmt->description);
+		fmt->description[sizeof fmt->description - 1] = 0;
+		fmt->pixelformat = format->fcc;
+		break;
+	}
+
+	case VIDIOC_TRY_FMT:
+	{
+		struct uvc_streaming_control probe;
+
+		if ((ret = uvc_acquire_privileges(handle)) < 0)
+			return ret;
+
+		return uvc_v4l2_try_format(video, arg, &probe, NULL, NULL);
+	}
+
+	case VIDIOC_S_FMT:
+		if ((ret = uvc_acquire_privileges(handle)) < 0)
+			return ret;
+
+		return uvc_v4l2_set_format(video, arg);
+
+	case VIDIOC_G_FMT:
+		return uvc_v4l2_get_format(video, arg);
+
+	/* Frame size enumeration */
+	case VIDIOC_ENUM_FRAMESIZES:
+	{
+		struct v4l2_frmsizeenum *fsize = arg;
+		struct uvc_format *format = NULL;
+		struct uvc_frame *frame;
+		int i;
+
+		/* Look for the given pixel format */
+		for (i = 0; i < video->streaming->nformats; i++) {
+			if (video->streaming->format[i].fcc ==
+					fsize->pixel_format) {
+				format = &video->streaming->format[i];
+				break;
+			}
+		}
+		if (format == NULL)
+			return -EINVAL;
+
+		if (fsize->index >= format->nframes)
+			return -EINVAL;
+
+		frame = &format->frame[fsize->index];
+		fsize->type = V4L2_FRMSIZE_TYPE_DISCRETE;
+		fsize->discrete.width = frame->wWidth;
+		fsize->discrete.height = frame->wHeight;
+		break;
+	}
+
+	/* Frame interval enumeration */
+	case VIDIOC_ENUM_FRAMEINTERVALS:
+	{
+		struct v4l2_frmivalenum *fival = arg;
+		struct uvc_format *format = NULL;
+		struct uvc_frame *frame = NULL;
+		int i;
+
+		/* Look for the given pixel format and frame size */
+		for (i = 0; i < video->streaming->nformats; i++) {
+			if (video->streaming->format[i].fcc ==
+					fival->pixel_format) {
+				format = &video->streaming->format[i];
+				break;
+			}
+		}
+		if (format == NULL)
+			return -EINVAL;
+
+		for (i = 0; i < format->nframes; i++) {
+			if (format->frame[i].wWidth == fival->width &&
+			    format->frame[i].wHeight == fival->height) {
+				frame = &format->frame[i];
+				break;
+			}
+		}
+		if (frame == NULL)
+			return -EINVAL;
+
+		if (frame->bFrameIntervalType) {
+			if (fival->index >= frame->bFrameIntervalType)
+				return -EINVAL;
+
+			fival->type = V4L2_FRMIVAL_TYPE_DISCRETE;
+			fival->discrete.numerator =
+				frame->dwFrameInterval[fival->index];
+			fival->discrete.denominator = 10000000;
+			uvc_simplify_fraction(&fival->discrete.numerator,
+				&fival->discrete.denominator, 8, 333);
+		} else {
+			fival->type = V4L2_FRMIVAL_TYPE_STEPWISE;
+			fival->stepwise.min.numerator =
+				frame->dwFrameInterval[0];
+			fival->stepwise.min.denominator = 10000000;
+			fival->stepwise.max.numerator =
+				frame->dwFrameInterval[1];
+			fival->stepwise.max.denominator = 10000000;
+			fival->stepwise.step.numerator =
+				frame->dwFrameInterval[2];
+			fival->stepwise.step.denominator = 10000000;
+			uvc_simplify_fraction(&fival->stepwise.min.numerator,
+				&fival->stepwise.min.denominator, 8, 333);
+			uvc_simplify_fraction(&fival->stepwise.max.numerator,
+				&fival->stepwise.max.denominator, 8, 333);
+			uvc_simplify_fraction(&fival->stepwise.step.numerator,
+				&fival->stepwise.step.denominator, 8, 333);
+		}
+		break;
+	}
+
+	/* Get & Set streaming parameters */
+	case VIDIOC_G_PARM:
+		return uvc_v4l2_get_streamparm(video, arg);
+
+	case VIDIOC_S_PARM:
+		if ((ret = uvc_acquire_privileges(handle)) < 0)
+			return ret;
+
+		return uvc_v4l2_set_streamparm(video, arg);
+
+	/* Cropping and scaling */
+	case VIDIOC_CROPCAP:
+	{
+		struct v4l2_cropcap *ccap = arg;
+		struct uvc_frame *frame = video->streaming->cur_frame;
+
+		if (ccap->type != V4L2_BUF_TYPE_VIDEO_CAPTURE)
+			return -EINVAL;
+
+		ccap->bounds.left = 0;
+		ccap->bounds.top = 0;
+		ccap->bounds.width = frame->wWidth;
+		ccap->bounds.height = frame->wHeight;
+
+		ccap->defrect = ccap->bounds;
+
+		ccap->pixelaspect.numerator = 1;
+		ccap->pixelaspect.denominator = 1;
+		break;
+	}
+
+	case VIDIOC_G_CROP:
+	case VIDIOC_S_CROP:
+		return -EINVAL;
+
+	/* Buffers & streaming */
+	case VIDIOC_REQBUFS:
+	{
+		struct v4l2_requestbuffers *rb = arg;
+		unsigned int bufsize =
+			video->streaming->ctrl.dwMaxVideoFrameSize;
+
+		if (rb->type != V4L2_BUF_TYPE_VIDEO_CAPTURE ||
+		    rb->memory != V4L2_MEMORY_MMAP)
+			return -EINVAL;
+
+		if ((ret = uvc_acquire_privileges(handle)) < 0)
+			return ret;
+
+		ret = uvc_alloc_buffers(&video->queue, rb->count, bufsize);
+		if (ret < 0)
+			return ret;
+
+		if (!(video->streaming->cur_format->flags &
+		    UVC_FMT_FLAG_COMPRESSED))
+			video->queue.flags |= UVC_QUEUE_DROP_INCOMPLETE;
+
+		rb->count = ret;
+		ret = 0;
+		break;
+	}
+
+	case VIDIOC_QUERYBUF:
+	{
+		struct v4l2_buffer *buf = arg;
+
+		if (buf->type != V4L2_BUF_TYPE_VIDEO_CAPTURE)
+			return -EINVAL;
+
+		if (!uvc_has_privileges(handle))
+			return -EBUSY;
+
+		return uvc_query_buffer(&video->queue, buf);
+	}
+
+	case VIDIOC_QBUF:
+		if (!uvc_has_privileges(handle))
+			return -EBUSY;
+
+		return uvc_queue_buffer(&video->queue, arg);
+
+	case VIDIOC_DQBUF:
+		if (!uvc_has_privileges(handle))
+			return -EBUSY;
+
+		return uvc_dequeue_buffer(&video->queue, arg,
+			file->f_flags & O_NONBLOCK);
+
+	case VIDIOC_STREAMON:
+	{
+		int *type = arg;
+
+		if (*type != V4L2_BUF_TYPE_VIDEO_CAPTURE)
+			return -EINVAL;
+
+		if (!uvc_has_privileges(handle))
+			return -EBUSY;
+
+		if ((ret = uvc_video_enable(video, 1)) < 0)
+			return ret;
+		break;
+	}
+
+	case VIDIOC_STREAMOFF:
+	{
+		int *type = arg;
+
+		if (*type != V4L2_BUF_TYPE_VIDEO_CAPTURE)
+			return -EINVAL;
+
+		if (!uvc_has_privileges(handle))
+			return -EBUSY;
+
+		return uvc_video_enable(video, 0);
+	}
+
+	/* Analog video standards make no sense for digital cameras. */
+	case VIDIOC_ENUMSTD:
+	case VIDIOC_QUERYSTD:
+	case VIDIOC_G_STD:
+	case VIDIOC_S_STD:
+
+	case VIDIOC_OVERLAY:
+
+	case VIDIOC_ENUMAUDIO:
+	case VIDIOC_ENUMAUDOUT:
+
+	case VIDIOC_ENUMOUTPUT:
+		uvc_trace(UVC_TRACE_IOCTL, "Unsupported ioctl 0x%08x\n", cmd);
+		return -EINVAL;
+
+	/* Dynamic controls. */
+	case UVCIOC_CTRL_ADD:
+	{
+		struct uvc_xu_control_info *xinfo = arg;
+		struct uvc_control_info *info;
+
+		if (!capable(CAP_SYS_ADMIN))
+			return -EPERM;
+
+		info = kmalloc(sizeof *info, GFP_KERNEL);
+		if (info == NULL)
+			return -ENOMEM;
+
+		memcpy(info->entity, xinfo->entity, sizeof info->entity);
+		info->index = xinfo->index;
+		info->selector = xinfo->selector;
+		info->size = xinfo->size;
+		info->flags = xinfo->flags;
+
+		info->flags |= UVC_CONTROL_GET_MIN | UVC_CONTROL_GET_MAX |
+				UVC_CONTROL_GET_RES | UVC_CONTROL_GET_DEF;
+
+		ret = uvc_ctrl_add_info(info);
+		if (ret < 0)
+			kfree(info);
+		break;
+	}
+
+	case UVCIOC_CTRL_MAP:
+	{
+		struct uvc_xu_control_mapping *xmap = arg;
+		struct uvc_control_mapping *map;
+
+		if (!capable(CAP_SYS_ADMIN))
+			return -EPERM;
+
+		map = kmalloc(sizeof *map, GFP_KERNEL);
+		if (map == NULL)
+			return -ENOMEM;
+
+		map->id = xmap->id;
+		memcpy(map->name, xmap->name, sizeof map->name);
+		memcpy(map->entity, xmap->entity, sizeof map->entity);
+		map->selector = xmap->selector;
+		map->size = xmap->size;
+		map->offset = xmap->offset;
+		map->v4l2_type = xmap->v4l2_type;
+		map->data_type = xmap->data_type;
+
+		ret = uvc_ctrl_add_mapping(map);
+		if (ret < 0)
+			kfree(map);
+		break;
+	}
+
+	case UVCIOC_CTRL_GET:
+		return uvc_xu_ctrl_query(video, arg, 0);
+
+	case UVCIOC_CTRL_SET:
+		return uvc_xu_ctrl_query(video, arg, 1);
+
+	default:
+		if ((ret = v4l_compat_translate_ioctl(inode, file, cmd, arg,
+			uvc_v4l2_do_ioctl)) == -ENOIOCTLCMD)
+			uvc_trace(UVC_TRACE_IOCTL, "Unknown ioctl 0x%08x\n",
+				  cmd);
+		return ret;
+	}
+
+	return ret;
+}
+
+static int uvc_v4l2_ioctl(struct inode *inode, struct file *file,
+		     unsigned int cmd, unsigned long arg)
+{
+	uvc_trace(UVC_TRACE_CALLS, "uvc_v4l2_ioctl\n");
+	return video_usercopy(inode, file, cmd, arg, uvc_v4l2_do_ioctl);
+}
+
+static ssize_t uvc_v4l2_read(struct file *file, char __user *data,
+		    size_t count, loff_t *ppos)
+{
+	uvc_trace(UVC_TRACE_CALLS, "uvc_v4l2_read: not implemented.\n");
+	return -ENODEV;
+}
+
+/*
+ * VMA operations.
+ */
+static void uvc_vm_open(struct vm_area_struct *vma)
+{
+	struct uvc_buffer *buffer = vma->vm_private_data;
+	buffer->vma_use_count++;
+}
+
+static void uvc_vm_close(struct vm_area_struct *vma)
+{
+	struct uvc_buffer *buffer = vma->vm_private_data;
+	buffer->vma_use_count--;
+}
+
+static struct vm_operations_struct uvc_vm_ops = {
+	.open		= uvc_vm_open,
+	.close		= uvc_vm_close,
+};
+
+static int uvc_v4l2_mmap(struct file *file, struct vm_area_struct *vma)
+{
+	struct video_device *vdev = video_devdata(file);
+	struct uvc_video_device *video = video_get_drvdata(vdev);
+	struct uvc_buffer *buffer;
+	struct page *page;
+	unsigned long addr, start, size;
+	unsigned int i;
+	int ret = 0;
+
+	uvc_trace(UVC_TRACE_CALLS, "uvc_v4l2_mmap\n");
+
+	start = vma->vm_start;
+	size = vma->vm_end - vma->vm_start;
+
+	mutex_lock(&video->queue.mutex);
+
+	for (i = 0; i < video->queue.count; ++i) {
+		buffer = &video->queue.buffer[i];
+		if ((buffer->buf.m.offset >> PAGE_SHIFT) == vma->vm_pgoff)
+			break;
+	}
+
+	if (i == video->queue.count || size != video->queue.buf_size) {
+		ret = -EINVAL;
+		goto done;
+	}
+
+	/*
+	 * VM_IO marks the area as being an mmaped region for I/O to a
+	 * device. It also prevents the region from being core dumped.
+	 */
+	vma->vm_flags |= VM_IO;
+
+	addr = (unsigned long)video->queue.mem + buffer->buf.m.offset;
+	while (size > 0) {
+		page = vmalloc_to_page((void *)addr);
+		if ((ret = vm_insert_page(vma, start, page)) < 0)
+			goto done;
+
+		start += PAGE_SIZE;
+		addr += PAGE_SIZE;
+		size -= PAGE_SIZE;
+	}
+
+	vma->vm_ops = &uvc_vm_ops;
+	vma->vm_private_data = buffer;
+	uvc_vm_open(vma);
+
+done:
+	mutex_unlock(&video->queue.mutex);
+	return ret;
+}
+
+static unsigned int uvc_v4l2_poll(struct file *file, poll_table *wait)
+{
+	struct video_device *vdev = video_devdata(file);
+	struct uvc_video_device *video = video_get_drvdata(vdev);
+
+	uvc_trace(UVC_TRACE_CALLS, "uvc_v4l2_poll\n");
+
+	return uvc_queue_poll(&video->queue, file, wait);
+}
+
+struct file_operations uvc_fops = {
+	.owner		= THIS_MODULE,
+	.open		= uvc_v4l2_open,
+	.release	= uvc_v4l2_release,
+	.ioctl		= uvc_v4l2_ioctl,
+	.compat_ioctl	= v4l_compat_ioctl32,
+	.llseek		= no_llseek,
+	.read		= uvc_v4l2_read,
+	.mmap		= uvc_v4l2_mmap,
+	.poll		= uvc_v4l2_poll,
+};