// SPDX-License-Identifier: GPL-2.0-or-later
/*
 *      uvc_v4l2.c  --  USB Video Class driver - V4L2 API
 *
 *      Copyright (C) 2005-2010
 *          Laurent Pinchart (laurent.pinchart@ideasonboard.com)
 */

#include <linux/compat.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/mm.h>
#include <linux/wait.h>
#include <linux/atomic.h>

#include <media/v4l2-common.h>
#include <media/v4l2-ctrls.h>
#include <media/v4l2-event.h>
#include <media/v4l2-ioctl.h>

#include "uvcvideo.h"

/* ------------------------------------------------------------------------
 * UVC ioctls
 */
static int uvc_ioctl_ctrl_map(struct uvc_video_chain *chain,
        struct uvc_xu_control_mapping *xmap)
{
        struct uvc_control_mapping *map;
        unsigned int size;
        int ret;

        map = kzalloc(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;

        switch (xmap->v4l2_type) {
        case V4L2_CTRL_TYPE_INTEGER:
        case V4L2_CTRL_TYPE_BOOLEAN:
        case V4L2_CTRL_TYPE_BUTTON:
                break;

        case V4L2_CTRL_TYPE_MENU:
                /* Prevent excessive memory consumption, as well as integer
                 * overflows.
                 */
                if (xmap->menu_count == 0 ||
                    xmap->menu_count > UVC_MAX_CONTROL_MENU_ENTRIES) {
                        ret = -EINVAL;
                        goto free_map;
                }

                size = xmap->menu_count * sizeof(*map->menu_info);
                map->menu_info = memdup_user(xmap->menu_info, size);
                if (IS_ERR(map->menu_info)) {
                        ret = PTR_ERR(map->menu_info);
                        goto free_map;
                }

                map->menu_count = xmap->menu_count;
                break;

        default:
                uvc_trace(UVC_TRACE_CONTROL, "Unsupported V4L2 control type "
                          "%u.\n", xmap->v4l2_type);
                ret = -ENOTTY;
                goto free_map;
        }

        ret = uvc_ctrl_add_mapping(chain, map);

        kfree(map->menu_info);
free_map:
        kfree(map);

        return ret;
}

/* ------------------------------------------------------------------------
 * V4L2 interface
 */

/*
 * 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 u32 uvc_v4l2_get_bytesperline(const struct uvc_format *format,
        const struct uvc_frame *frame)
{
        switch (format->fcc) {
        case V4L2_PIX_FMT_NV12:
        case V4L2_PIX_FMT_YVU420:
        case V4L2_PIX_FMT_YUV420:
        case V4L2_PIX_FMT_M420:
                return frame->wWidth;

        default:
                return format->bpp * frame->wWidth / 8;
        }
}

static int uvc_v4l2_try_format(struct uvc_streaming *stream,
        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 != stream->type)
                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, use the default
         * format otherwise.
         */
        for (i = 0; i < stream->nformats; ++i) {
                format = &stream->format[i];
                if (format->fcc == fmt->fmt.pix.pixelformat)
                        break;
        }

        if (i == stream->nformats) {
                format = stream->def_format;
                fmt->fmt.pix.pixelformat = format->fcc;
        }

        /* 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).
         */
        mutex_lock(&stream->mutex);
        if (stream->dev->quirks & UVC_QUIRK_PROBE_EXTRAFIELDS)
                probe->dwMaxVideoFrameSize =
                        stream->ctrl.dwMaxVideoFrameSize;

        /* Probe the device. */
        ret = uvc_probe_video(stream, probe);
        mutex_unlock(&stream->mutex);
        if (ret < 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 = uvc_v4l2_get_bytesperline(format, frame);
        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_streaming *stream,
        struct v4l2_format *fmt)
{
        struct uvc_format *format;
        struct uvc_frame *frame;
        int ret = 0;

        if (fmt->type != stream->type)
                return -EINVAL;

        mutex_lock(&stream->mutex);
        format = stream->cur_format;
        frame = stream->cur_frame;

        if (format == NULL || frame == NULL) {
                ret = -EINVAL;
                goto done;
        }

        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 = uvc_v4l2_get_bytesperline(format, frame);
        fmt->fmt.pix.sizeimage = stream->ctrl.dwMaxVideoFrameSize;
        fmt->fmt.pix.colorspace = format->colorspace;
        fmt->fmt.pix.priv = 0;

done:
        mutex_unlock(&stream->mutex);
        return ret;
}

static int uvc_v4l2_set_format(struct uvc_streaming *stream,
        struct v4l2_format *fmt)
{
        struct uvc_streaming_control probe;
        struct uvc_format *format;
        struct uvc_frame *frame;
        int ret;

        if (fmt->type != stream->type)
                return -EINVAL;

        ret = uvc_v4l2_try_format(stream, fmt, &probe, &format, &frame);
        if (ret < 0)
                return ret;

        mutex_lock(&stream->mutex);

        if (uvc_queue_allocated(&stream->queue)) {
                ret = -EBUSY;
                goto done;
        }

        stream->ctrl = probe;
        stream->cur_format = format;
        stream->cur_frame = frame;

done:
        mutex_unlock(&stream->mutex);
        return ret;
}

static int uvc_v4l2_get_streamparm(struct uvc_streaming *stream,
                struct v4l2_streamparm *parm)
{
        u32 numerator, denominator;

        if (parm->type != stream->type)
                return -EINVAL;

        mutex_lock(&stream->mutex);
        numerator = stream->ctrl.dwFrameInterval;
        mutex_unlock(&stream->mutex);

        denominator = 10000000;
        uvc_simplify_fraction(&numerator, &denominator, 8, 333);

        memset(parm, 0, sizeof(*parm));
        parm->type = stream->type;

        if (stream->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;
        } else {
                parm->parm.output.capability = V4L2_CAP_TIMEPERFRAME;
                parm->parm.output.outputmode = 0;
                parm->parm.output.timeperframe.numerator = numerator;
                parm->parm.output.timeperframe.denominator = denominator;
        }

        return 0;
}

static int uvc_v4l2_set_streamparm(struct uvc_streaming *stream,
                struct v4l2_streamparm *parm)
{
        struct uvc_streaming_control probe;
        struct v4l2_fract timeperframe;
        struct uvc_format *format;
        struct uvc_frame *frame;
        u32 interval, maxd;
        unsigned int i;
        int ret;

        if (parm->type != stream->type)
                return -EINVAL;

        if (parm->type == V4L2_BUF_TYPE_VIDEO_CAPTURE)
                timeperframe = parm->parm.capture.timeperframe;
        else
                timeperframe = parm->parm.output.timeperframe;

        interval = uvc_fraction_to_interval(timeperframe.numerator,
                timeperframe.denominator);
        uvc_trace(UVC_TRACE_FORMAT, "Setting frame interval to %u/%u (%u).\n",
                timeperframe.numerator, timeperframe.denominator, interval);

        mutex_lock(&stream->mutex);

        if (uvc_queue_streaming(&stream->queue)) {
                mutex_unlock(&stream->mutex);
                return -EBUSY;
        }

        format = stream->cur_format;
        frame = stream->cur_frame;
        probe = stream->ctrl;
        probe.dwFrameInterval = uvc_try_frame_interval(frame, interval);
        maxd = abs((s32)probe.dwFrameInterval - interval);

        /* Try frames with matching size to find the best frame interval. */
        for (i = 0; i < format->nframes && maxd != 0; i++) {
                u32 d, ival;

                if (&format->frame[i] == stream->cur_frame)
                        continue;

                if (format->frame[i].wWidth != stream->cur_frame->wWidth ||
                    format->frame[i].wHeight != stream->cur_frame->wHeight)
                        continue;

                ival = uvc_try_frame_interval(&format->frame[i], interval);
                d = abs((s32)ival - interval);
                if (d >= maxd)
                        continue;

                frame = &format->frame[i];
                probe.bFrameIndex = frame->bFrameIndex;
                probe.dwFrameInterval = ival;
                maxd = d;
        }

        /* Probe the device with the new settings. */
        ret = uvc_probe_video(stream, &probe);
        if (ret < 0) {
                mutex_unlock(&stream->mutex);
                return ret;
        }

        stream->ctrl = probe;
        stream->cur_frame = frame;
        mutex_unlock(&stream->mutex);

        /* Return the actual frame period. */
        timeperframe.numerator = probe.dwFrameInterval;
        timeperframe.denominator = 10000000;
        uvc_simplify_fraction(&timeperframe.numerator,
                &timeperframe.denominator, 8, 333);

        if (parm->type == V4L2_BUF_TYPE_VIDEO_CAPTURE)
                parm->parm.capture.timeperframe = timeperframe;
        else
                parm->parm.output.timeperframe = timeperframe;

        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 that requires privileges will
 * automatically acquire the required privileges if possible, or return -EBUSY
 * otherwise. Privileges are dismissed when closing the instance or when
 * freeing the video buffers using VIDIOC_REQBUFS.
 *
 * Operations that require privileges are:
 *
 * - VIDIOC_S_INPUT
 * - VIDIOC_S_PARM
 * - VIDIOC_S_FMT
 * - VIDIOC_REQBUFS
 */
static int uvc_acquire_privileges(struct uvc_fh *handle)
{
        /* 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. */
        if (atomic_inc_return(&handle->stream->active) != 1) {
                atomic_dec(&handle->stream->active);
                return -EBUSY;
        }

        handle->state = UVC_HANDLE_ACTIVE;
        return 0;
}

static void uvc_dismiss_privileges(struct uvc_fh *handle)
{
        if (handle->state == UVC_HANDLE_ACTIVE)
                atomic_dec(&handle->stream->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 file *file)
{
        struct uvc_streaming *stream;
        struct uvc_fh *handle;
        int ret = 0;

        uvc_trace(UVC_TRACE_CALLS, "uvc_v4l2_open\n");
        stream = video_drvdata(file);

        ret = usb_autopm_get_interface(stream->dev->intf);
        if (ret < 0)
                return ret;

        /* Create the device handle. */
        handle = kzalloc(sizeof(*handle), GFP_KERNEL);
        if (handle == NULL) {
                usb_autopm_put_interface(stream->dev->intf);
                return -ENOMEM;
        }

        mutex_lock(&stream->dev->lock);
        if (stream->dev->users == 0) {
                ret = uvc_status_start(stream->dev, GFP_KERNEL);
                if (ret < 0) {
                        mutex_unlock(&stream->dev->lock);
                        usb_autopm_put_interface(stream->dev->intf);
                        kfree(handle);
                        return ret;
                }
        }

        stream->dev->users++;
        mutex_unlock(&stream->dev->lock);

        v4l2_fh_init(&handle->vfh, &stream->vdev);
        v4l2_fh_add(&handle->vfh);
        handle->chain = stream->chain;
        handle->stream = stream;
        handle->state = UVC_HANDLE_PASSIVE;
        file->private_data = handle;

        return 0;
}

static int uvc_v4l2_release(struct file *file)
{
        struct uvc_fh *handle = file->private_data;
        struct uvc_streaming *stream = handle->stream;

        uvc_trace(UVC_TRACE_CALLS, "uvc_v4l2_release\n");

        /* Only free resources if this is a privileged handle. */
        if (uvc_has_privileges(handle))
                uvc_queue_release(&stream->queue);

        /* Release the file handle. */
        uvc_dismiss_privileges(handle);
        v4l2_fh_del(&handle->vfh);
        v4l2_fh_exit(&handle->vfh);
        kfree(handle);
        file->private_data = NULL;

        mutex_lock(&stream->dev->lock);
        if (--stream->dev->users == 0)
                uvc_status_stop(stream->dev);
        mutex_unlock(&stream->dev->lock);

        usb_autopm_put_interface(stream->dev->intf);
        return 0;
}

static int uvc_ioctl_querycap(struct file *file, void *fh,
                              struct v4l2_capability *cap)
{
        struct video_device *vdev = video_devdata(file);
        struct uvc_fh *handle = file->private_data;
        struct uvc_video_chain *chain = handle->chain;
        struct uvc_streaming *stream = handle->stream;

        strscpy(cap->driver, "uvcvideo", sizeof(cap->driver));
        strscpy(cap->card, vdev->name, sizeof(cap->card));
        usb_make_path(stream->dev->udev, cap->bus_info, sizeof(cap->bus_info));
        cap->capabilities = V4L2_CAP_DEVICE_CAPS | V4L2_CAP_STREAMING
                          | chain->caps;

        return 0;
}

static int uvc_ioctl_enum_fmt(struct uvc_streaming *stream,
                              struct v4l2_fmtdesc *fmt)
{
        struct uvc_format *format;
        enum v4l2_buf_type type = fmt->type;
        u32 index = fmt->index;

        if (fmt->type != stream->type || fmt->index >= stream->nformats)
                return -EINVAL;

        memset(fmt, 0, sizeof(*fmt));
        fmt->index = index;
        fmt->type = type;

        format = &stream->format[fmt->index];
        fmt->flags = 0;
        if (format->flags & UVC_FMT_FLAG_COMPRESSED)
                fmt->flags |= V4L2_FMT_FLAG_COMPRESSED;
        strscpy(fmt->description, format->name, sizeof(fmt->description));
        fmt->description[sizeof(fmt->description) - 1] = 0;
        fmt->pixelformat = format->fcc;
        return 0;
}

static int uvc_ioctl_enum_fmt_vid_cap(struct file *file, void *fh,
                                      struct v4l2_fmtdesc *fmt)
{
        struct uvc_fh *handle = fh;
        struct uvc_streaming *stream = handle->stream;

        return uvc_ioctl_enum_fmt(stream, fmt);
}

static int uvc_ioctl_enum_fmt_vid_out(struct file *file, void *fh,
                                      struct v4l2_fmtdesc *fmt)
{
        struct uvc_fh *handle = fh;
        struct uvc_streaming *stream = handle->stream;

        return uvc_ioctl_enum_fmt(stream, fmt);
}

static int uvc_ioctl_g_fmt_vid_cap(struct file *file, void *fh,
                                   struct v4l2_format *fmt)
{
        struct uvc_fh *handle = fh;
        struct uvc_streaming *stream = handle->stream;

        return uvc_v4l2_get_format(stream, fmt);
}

static int uvc_ioctl_g_fmt_vid_out(struct file *file, void *fh,
                                   struct v4l2_format *fmt)
{
        struct uvc_fh *handle = fh;
        struct uvc_streaming *stream = handle->stream;

        return uvc_v4l2_get_format(stream, fmt);
}

static int uvc_ioctl_s_fmt_vid_cap(struct file *file, void *fh,
                                   struct v4l2_format *fmt)
{
        struct uvc_fh *handle = fh;
        struct uvc_streaming *stream = handle->stream;
        int ret;

        ret = uvc_acquire_privileges(handle);
        if (ret < 0)
                return ret;

        return uvc_v4l2_set_format(stream, fmt);
}

static int uvc_ioctl_s_fmt_vid_out(struct file *file, void *fh,
                                   struct v4l2_format *fmt)
{
        struct uvc_fh *handle = fh;
        struct uvc_streaming *stream = handle->stream;
        int ret;

        ret = uvc_acquire_privileges(handle);
        if (ret < 0)
                return ret;

        return uvc_v4l2_set_format(stream, fmt);
}

static int uvc_ioctl_try_fmt_vid_cap(struct file *file, void *fh,
                                     struct v4l2_format *fmt)
{
        struct uvc_fh *handle = fh;
        struct uvc_streaming *stream = handle->stream;
        struct uvc_streaming_control probe;

        return uvc_v4l2_try_format(stream, fmt, &probe, NULL, NULL);
}

static int uvc_ioctl_try_fmt_vid_out(struct file *file, void *fh,
                                     struct v4l2_format *fmt)
{
        struct uvc_fh *handle = fh;
        struct uvc_streaming *stream = handle->stream;
        struct uvc_streaming_control probe;

        return uvc_v4l2_try_format(stream, fmt, &probe, NULL, NULL);
}

static int uvc_ioctl_reqbufs(struct file *file, void *fh,
                             struct v4l2_requestbuffers *rb)
{
        struct uvc_fh *handle = fh;
        struct uvc_streaming *stream = handle->stream;
        int ret;

        ret = uvc_acquire_privileges(handle);
        if (ret < 0)
                return ret;

        mutex_lock(&stream->mutex);
        ret = uvc_request_buffers(&stream->queue, rb);
        mutex_unlock(&stream->mutex);
        if (ret < 0)
                return ret;

        if (ret == 0)
                uvc_dismiss_privileges(handle);

        return 0;
}

static int uvc_ioctl_querybuf(struct file *file, void *fh,
                              struct v4l2_buffer *buf)
{
        struct uvc_fh *handle = fh;
        struct uvc_streaming *stream = handle->stream;

        if (!uvc_has_privileges(handle))
                return -EBUSY;

        return uvc_query_buffer(&stream->queue, buf);
}

static int uvc_ioctl_qbuf(struct file *file, void *fh, struct v4l2_buffer *buf)
{
        struct uvc_fh *handle = fh;
        struct uvc_streaming *stream = handle->stream;

        if (!uvc_has_privileges(handle))
                return -EBUSY;

        return uvc_queue_buffer(&stream->queue,
                                stream->vdev.v4l2_dev->mdev, buf);
}

static int uvc_ioctl_expbuf(struct file *file, void *fh,
                            struct v4l2_exportbuffer *exp)
{
        struct uvc_fh *handle = fh;
        struct uvc_streaming *stream = handle->stream;

        if (!uvc_has_privileges(handle))
                return -EBUSY;

        return uvc_export_buffer(&stream->queue, exp);
}

static int uvc_ioctl_dqbuf(struct file *file, void *fh, struct v4l2_buffer *buf)
{
        struct uvc_fh *handle = fh;
        struct uvc_streaming *stream = handle->stream;

        if (!uvc_has_privileges(handle))
                return -EBUSY;

        return uvc_dequeue_buffer(&stream->queue, buf,
                                  file->f_flags & O_NONBLOCK);
}

static int uvc_ioctl_create_bufs(struct file *file, void *fh,
                                  struct v4l2_create_buffers *cb)
{
        struct uvc_fh *handle = fh;
        struct uvc_streaming *stream = handle->stream;
        int ret;

        ret = uvc_acquire_privileges(handle);
        if (ret < 0)
                return ret;

        return uvc_create_buffers(&stream->queue, cb);
}

static int uvc_ioctl_streamon(struct file *file, void *fh,
                              enum v4l2_buf_type type)
{
        struct uvc_fh *handle = fh;
        struct uvc_streaming *stream = handle->stream;
        int ret;

        if (!uvc_has_privileges(handle))
                return -EBUSY;

        mutex_lock(&stream->mutex);
        ret = uvc_queue_streamon(&stream->queue, type);
        mutex_unlock(&stream->mutex);

        return ret;
}

static int uvc_ioctl_streamoff(struct file *file, void *fh,
                               enum v4l2_buf_type type)
{
        struct uvc_fh *handle = fh;
        struct uvc_streaming *stream = handle->stream;

        if (!uvc_has_privileges(handle))
                return -EBUSY;

        mutex_lock(&stream->mutex);
        uvc_queue_streamoff(&stream->queue, type);
        mutex_unlock(&stream->mutex);

        return 0;
}

static int uvc_ioctl_enum_input(struct file *file, void *fh,
                                struct v4l2_input *input)
{
        struct uvc_fh *handle = fh;
        struct uvc_video_chain *chain = handle->chain;
        const struct uvc_entity *selector = chain->selector;
        struct uvc_entity *iterm = NULL;
        u32 index = input->index;
        int pin = 0;

        if (selector == NULL ||
            (chain->dev->quirks & UVC_QUIRK_IGNORE_SELECTOR_UNIT)) {
                if (index != 0)
                        return -EINVAL;
                list_for_each_entry(iterm, &chain->entities, chain) {
                        if (UVC_ENTITY_IS_ITERM(iterm))
                                break;
                }
                pin = iterm->id;
        } else if (index < selector->bNrInPins) {
                pin = selector->baSourceID[index];
                list_for_each_entry(iterm, &chain->entities, chain) {
                        if (!UVC_ENTITY_IS_ITERM(iterm))
                                continue;
                        if (iterm->id == pin)
                                break;
                }
        }

        if (iterm == NULL || iterm->id != pin)
                return -EINVAL;

        memset(input, 0, sizeof(*input));
        input->index = index;
        strscpy(input->name, iterm->name, sizeof(input->name));
        if (UVC_ENTITY_TYPE(iterm) == UVC_ITT_CAMERA)
                input->type = V4L2_INPUT_TYPE_CAMERA;

        return 0;
}

static int uvc_ioctl_g_input(struct file *file, void *fh, unsigned int *input)
{
        struct uvc_fh *handle = fh;
        struct uvc_video_chain *chain = handle->chain;
        int ret;
        u8 i;

        if (chain->selector == NULL ||
            (chain->dev->quirks & UVC_QUIRK_IGNORE_SELECTOR_UNIT)) {
                *input = 0;
                return 0;
        }

        ret = uvc_query_ctrl(chain->dev, UVC_GET_CUR, chain->selector->id,
                             chain->dev->intfnum,  UVC_SU_INPUT_SELECT_CONTROL,
                             &i, 1);
        if (ret < 0)
                return ret;

        *input = i - 1;
        return 0;
}

static int uvc_ioctl_s_input(struct file *file, void *fh, unsigned int input)
{
        struct uvc_fh *handle = fh;
        struct uvc_video_chain *chain = handle->chain;
        int ret;
        u32 i;

        ret = uvc_acquire_privileges(handle);
        if (ret < 0)
                return ret;

        if (chain->selector == NULL ||
            (chain->dev->quirks & UVC_QUIRK_IGNORE_SELECTOR_UNIT)) {
                if (input)
                        return -EINVAL;
                return 0;
        }

        if (input >= chain->selector->bNrInPins)
                return -EINVAL;

        i = input + 1;
        return uvc_query_ctrl(chain->dev, UVC_SET_CUR, chain->selector->id,
                              chain->dev->intfnum, UVC_SU_INPUT_SELECT_CONTROL,
                              &i, 1);
}

static int uvc_ioctl_queryctrl(struct file *file, void *fh,
                               struct v4l2_queryctrl *qc)
{
        struct uvc_fh *handle = fh;
        struct uvc_video_chain *chain = handle->chain;

        return uvc_query_v4l2_ctrl(chain, qc);
}

static int uvc_ioctl_query_ext_ctrl(struct file *file, void *fh,
                                    struct v4l2_query_ext_ctrl *qec)
{
        struct uvc_fh *handle = fh;
        struct uvc_video_chain *chain = handle->chain;
        struct v4l2_queryctrl qc = { qec->id };
        int ret;

        ret = uvc_query_v4l2_ctrl(chain, &qc);
        if (ret)
                return ret;

        qec->id = qc.id;
        qec->type = qc.type;
        strscpy(qec->name, qc.name, sizeof(qec->name));
        qec->minimum = qc.minimum;
        qec->maximum = qc.maximum;
        qec->step = qc.step;
        qec->default_value = qc.default_value;
        qec->flags = qc.flags;
        qec->elem_size = 4;
        qec->elems = 1;
        qec->nr_of_dims = 0;
        memset(qec->dims, 0, sizeof(qec->dims));
        memset(qec->reserved, 0, sizeof(qec->reserved));

        return 0;
}

static int uvc_ioctl_g_ctrl(struct file *file, void *fh,
                            struct v4l2_control *ctrl)
{
        struct uvc_fh *handle = fh;
        struct uvc_video_chain *chain = handle->chain;
        struct v4l2_ext_control xctrl;
        int ret;

        memset(&xctrl, 0, sizeof(xctrl));
        xctrl.id = ctrl->id;

        ret = uvc_ctrl_begin(chain);
        if (ret < 0)
                return ret;

        ret = uvc_ctrl_get(chain, &xctrl);
        uvc_ctrl_rollback(handle);
        if (ret < 0)
                return ret;

        ctrl->value = xctrl.value;
        return 0;
}

static int uvc_ioctl_s_ctrl(struct file *file, void *fh,
                            struct v4l2_control *ctrl)
{
        struct uvc_fh *handle = fh;
        struct uvc_video_chain *chain = handle->chain;
        struct v4l2_ext_control xctrl;
        int ret;

        memset(&xctrl, 0, sizeof(xctrl));
        xctrl.id = ctrl->id;
        xctrl.value = ctrl->value;

        ret = uvc_ctrl_begin(chain);
        if (ret < 0)
                return ret;

        ret = uvc_ctrl_set(handle, &xctrl);
        if (ret < 0) {
                uvc_ctrl_rollback(handle);
                return ret;
        }

        ret = uvc_ctrl_commit(handle, &xctrl, 1);
        if (ret < 0)

                return ret;

        ctrl->value = xctrl.value;
        return 0;
}

static int uvc_ioctl_g_ext_ctrls(struct file *file, void *fh,
                                 struct v4l2_ext_controls *ctrls)
{
        struct uvc_fh *handle = fh;
        struct uvc_video_chain *chain = handle->chain;
        struct v4l2_ext_control *ctrl = ctrls->controls;
        unsigned int i;
        int ret;

        if (ctrls->which == V4L2_CTRL_WHICH_DEF_VAL) {
                for (i = 0; i < ctrls->count; ++ctrl, ++i) {
                        struct v4l2_queryctrl qc = { .id = ctrl->id };

                        ret = uvc_query_v4l2_ctrl(chain, &qc);
                        if (ret < 0) {
                                ctrls->error_idx = i;
                                return ret;
                        }

                        ctrl->value = qc.default_value;
                }

                return 0;
        }

        ret = uvc_ctrl_begin(chain);
        if (ret < 0)
                return ret;

        for (i = 0; i < ctrls->count; ++ctrl, ++i) {
                ret = uvc_ctrl_get(chain, ctrl);
                if (ret < 0) {
                        uvc_ctrl_rollback(handle);
                        ctrls->error_idx = i;
                        return ret;
                }
        }

        ctrls->error_idx = 0;

        return uvc_ctrl_rollback(handle);
}

static int uvc_ioctl_s_try_ext_ctrls(struct uvc_fh *handle,
                                     struct v4l2_ext_controls *ctrls,
                                     bool commit)
{
        struct v4l2_ext_control *ctrl = ctrls->controls;
        struct uvc_video_chain *chain = handle->chain;
        unsigned int i;
        int ret;

        /* Default value cannot be changed */
        if (ctrls->which == V4L2_CTRL_WHICH_DEF_VAL)
                return -EINVAL;

        ret = uvc_ctrl_begin(chain);
        if (ret < 0)
                return ret;

        for (i = 0; i < ctrls->count; ++ctrl, ++i) {
                ret = uvc_ctrl_set(handle, ctrl);
                if (ret < 0) {
                        uvc_ctrl_rollback(handle);
                        ctrls->error_idx = commit ? ctrls->count : i;
                        return ret;
                }
        }

        ctrls->error_idx = 0;

        if (commit)
                return uvc_ctrl_commit(handle, ctrls->controls, ctrls->count);
        else
                return uvc_ctrl_rollback(handle);
}

static int uvc_ioctl_s_ext_ctrls(struct file *file, void *fh,
                                 struct v4l2_ext_controls *ctrls)
{
        struct uvc_fh *handle = fh;

        return uvc_ioctl_s_try_ext_ctrls(handle, ctrls, true);
}

static int uvc_ioctl_try_ext_ctrls(struct file *file, void *fh,
                                   struct v4l2_ext_controls *ctrls)
{
        struct uvc_fh *handle = fh;

        return uvc_ioctl_s_try_ext_ctrls(handle, ctrls, false);
}

static int uvc_ioctl_querymenu(struct file *file, void *fh,
                               struct v4l2_querymenu *qm)
{
        struct uvc_fh *handle = fh;
        struct uvc_video_chain *chain = handle->chain;

        return uvc_query_v4l2_menu(chain, qm);
}

static int uvc_ioctl_g_selection(struct file *file, void *fh,
                                 struct v4l2_selection *sel)
{
        struct uvc_fh *handle = fh;
        struct uvc_streaming *stream = handle->stream;

        if (sel->type != stream->type)
                return -EINVAL;

        switch (sel->target) {
        case V4L2_SEL_TGT_CROP_DEFAULT:
        case V4L2_SEL_TGT_CROP_BOUNDS:
                if (stream->type != V4L2_BUF_TYPE_VIDEO_CAPTURE)
                        return -EINVAL;
                break;
        case V4L2_SEL_TGT_COMPOSE_DEFAULT:
        case V4L2_SEL_TGT_COMPOSE_BOUNDS:
                if (stream->type != V4L2_BUF_TYPE_VIDEO_OUTPUT)
                        return -EINVAL;
                break;
        default:
                return -EINVAL;
        }

        sel->r.left = 0;
        sel->r.top = 0;
        mutex_lock(&stream->mutex);
        sel->r.width = stream->cur_frame->wWidth;
        sel->r.height = stream->cur_frame->wHeight;
        mutex_unlock(&stream->mutex);

        return 0;
}

static int uvc_ioctl_g_parm(struct file *file, void *fh,
                            struct v4l2_streamparm *parm)
{
        struct uvc_fh *handle = fh;
        struct uvc_streaming *stream = handle->stream;

        return uvc_v4l2_get_streamparm(stream, parm);
}

static int uvc_ioctl_s_parm(struct file *file, void *fh,
                            struct v4l2_streamparm *parm)
{
        struct uvc_fh *handle = fh;
        struct uvc_streaming *stream = handle->stream;
        int ret;

        ret = uvc_acquire_privileges(handle);
        if (ret < 0)
                return ret;

        return uvc_v4l2_set_streamparm(stream, parm);
}

static int uvc_ioctl_enum_framesizes(struct file *file, void *fh,
                                     struct v4l2_frmsizeenum *fsize)
{
        struct uvc_fh *handle = fh;
        struct uvc_streaming *stream = handle->stream;
        struct uvc_format *format = NULL;
        struct uvc_frame *frame = NULL;
        unsigned int index;
        unsigned int i;

        /* Look for the given pixel format */
        for (i = 0; i < stream->nformats; i++) {
                if (stream->format[i].fcc == fsize->pixel_format) {
                        format = &stream->format[i];
                        break;
                }
        }
        if (format == NULL)
                return -EINVAL;

        /* Skip duplicate frame sizes */
        for (i = 0, index = 0; i < format->nframes; i++) {
                if (frame && frame->wWidth == format->frame[i].wWidth &&
                    frame->wHeight == format->frame[i].wHeight)
                        continue;
                frame = &format->frame[i];
                if (index == fsize->index)
                        break;
                index++;
        }

        if (i == format->nframes)
                return -EINVAL;

        fsize->type = V4L2_FRMSIZE_TYPE_DISCRETE;
        fsize->discrete.width = frame->wWidth;
        fsize->discrete.height = frame->wHeight;
        return 0;
}

static int uvc_ioctl_enum_frameintervals(struct file *file, void *fh,
                                         struct v4l2_frmivalenum *fival)
{
        struct uvc_fh *handle = fh;
        struct uvc_streaming *stream = handle->stream;
        struct uvc_format *format = NULL;
        struct uvc_frame *frame = NULL;
        unsigned int nintervals;
        unsigned int index;
        unsigned int i;

        /* Look for the given pixel format and frame size */
        for (i = 0; i < stream->nformats; i++) {
                if (stream->format[i].fcc == fival->pixel_format) {
                        format = &stream->format[i];
                        break;
                }
        }
        if (format == NULL)
                return -EINVAL;

        index = fival->index;
        for (i = 0; i < format->nframes; i++) {
                if (format->frame[i].wWidth == fival->width &&
                    format->frame[i].wHeight == fival->height) {
                        frame = &format->frame[i];
                        nintervals = frame->bFrameIntervalType ?: 1;
                        if (index < nintervals)
                                break;
                        index -= nintervals;
                }
        }
        if (i == format->nframes)
                return -EINVAL;

        if (frame->bFrameIntervalType) {
                fival->type = V4L2_FRMIVAL_TYPE_DISCRETE;
                fival->discrete.numerator =
                        frame->dwFrameInterval[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);
        }

        return 0;
}

static int uvc_ioctl_subscribe_event(struct v4l2_fh *fh,
                                     const struct v4l2_event_subscription *sub)
{
        switch (sub->type) {
        case V4L2_EVENT_CTRL:
                return v4l2_event_subscribe(fh, sub, 0, &uvc_ctrl_sub_ev_ops);
        default:
                return -EINVAL;
        }
}

static long uvc_ioctl_default(struct file *file, void *fh, bool valid_prio,
                              unsigned int cmd, void *arg)
{
        struct uvc_fh *handle = fh;
        struct uvc_video_chain *chain = handle->chain;

        switch (cmd) {
        /* Dynamic controls. */
        case UVCIOC_CTRL_MAP:
                return uvc_ioctl_ctrl_map(chain, arg);

        case UVCIOC_CTRL_QUERY:
                return uvc_xu_ctrl_query(chain, arg);

        default:
                return -ENOTTY;
        }
}

#ifdef CONFIG_COMPAT
struct uvc_xu_control_mapping32 {
        u32 id;
        u8 name[32];
        u8 entity[16];
        u8 selector;

        u8 size;
        u8 offset;
        u32 v4l2_type;
        u32 data_type;

        compat_caddr_t menu_info;
        u32 menu_count;

        u32 reserved[4];
};

static int uvc_v4l2_get_xu_mapping(struct uvc_xu_control_mapping *kp,
                        const struct uvc_xu_control_mapping32 __user *up)
{
        struct uvc_xu_control_mapping32 *p = (void *)kp;
        compat_caddr_t info;
        u32 count;

        if (copy_from_user(p, up, sizeof(*p)))
                return -EFAULT;

        count = p->menu_count;
        info = p->menu_info;

        memset(kp->reserved, 0, sizeof(kp->reserved));
        kp->menu_info = count ? compat_ptr(info) : NULL;
        kp->menu_count = count;
        return 0;
}

static int uvc_v4l2_put_xu_mapping(const struct uvc_xu_control_mapping *kp,
                        struct uvc_xu_control_mapping32 __user *up)
{
        if (copy_to_user(up, kp, offsetof(typeof(*up), menu_info)) ||
            put_user(kp->menu_count, &up->menu_count))
                return -EFAULT;

        if (clear_user(up->reserved, sizeof(up->reserved)))
                return -EFAULT;

        return 0;
}

struct uvc_xu_control_query32 {
        u8 unit;
        u8 selector;
        u8 query;
        u16 size;
        compat_caddr_t data;
};

static int uvc_v4l2_get_xu_query(struct uvc_xu_control_query *kp,
                        const struct uvc_xu_control_query32 __user *up)
{
        struct uvc_xu_control_query32 v;

        if (copy_from_user(&v, up, sizeof(v)))
                return -EFAULT;

        *kp = (struct uvc_xu_control_query){
                .unit = v.unit,
                .selector = v.selector,
                .query = v.query,
                .size = v.size,
                .data = v.size ? compat_ptr(v.data) : NULL
        };
        return 0;
}

static int uvc_v4l2_put_xu_query(const struct uvc_xu_control_query *kp,
                        struct uvc_xu_control_query32 __user *up)
{
        if (copy_to_user(up, kp, offsetof(typeof(*up), data)))
                return -EFAULT;
        return 0;
}

#define UVCIOC_CTRL_MAP32       _IOWR('u', 0x20, struct uvc_xu_control_mapping32)
#define UVCIOC_CTRL_QUERY32     _IOWR('u', 0x21, struct uvc_xu_control_query32)

static long uvc_v4l2_compat_ioctl32(struct file *file,
                     unsigned int cmd, unsigned long arg)
{
        struct uvc_fh *handle = file->private_data;
        union {
                struct uvc_xu_control_mapping xmap;
                struct uvc_xu_control_query xqry;
        } karg;
        void __user *up = compat_ptr(arg);
        long ret;

        switch (cmd) {
        case UVCIOC_CTRL_MAP32:
                ret = uvc_v4l2_get_xu_mapping(&karg.xmap, up);
                if (ret)
                        return ret;
                ret = uvc_ioctl_ctrl_map(handle->chain, &karg.xmap);
                if (ret)
                        return ret;
                ret = uvc_v4l2_put_xu_mapping(&karg.xmap, up);
                if (ret)
                        return ret;

                break;

        case UVCIOC_CTRL_QUERY32:
                ret = uvc_v4l2_get_xu_query(&karg.xqry, up);
                if (ret)
                        return ret;
                ret = uvc_xu_ctrl_query(handle->chain, &karg.xqry);
                if (ret)
                        return ret;
                ret = uvc_v4l2_put_xu_query(&karg.xqry, up);
                if (ret)
                        return ret;
                break;

        default:
                return -ENOIOCTLCMD;
        }

        return ret;
}
#endif

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 -EINVAL;
}

static int uvc_v4l2_mmap(struct file *file, struct vm_area_struct *vma)
{
        struct uvc_fh *handle = file->private_data;
        struct uvc_streaming *stream = handle->stream;

        uvc_trace(UVC_TRACE_CALLS, "uvc_v4l2_mmap\n");

        return uvc_queue_mmap(&stream->queue, vma);
}

static __poll_t uvc_v4l2_poll(struct file *file, poll_table *wait)
{
        struct uvc_fh *handle = file->private_data;
        struct uvc_streaming *stream = handle->stream;

        uvc_trace(UVC_TRACE_CALLS, "uvc_v4l2_poll\n");

        return uvc_queue_poll(&stream->queue, file, wait);
}

#ifndef CONFIG_MMU
static unsigned long uvc_v4l2_get_unmapped_area(struct file *file,
                unsigned long addr, unsigned long len, unsigned long pgoff,
                unsigned long flags)
{
        struct uvc_fh *handle = file->private_data;
        struct uvc_streaming *stream = handle->stream;

        uvc_trace(UVC_TRACE_CALLS, "uvc_v4l2_get_unmapped_area\n");

        return uvc_queue_get_unmapped_area(&stream->queue, pgoff);
}
#endif

const struct v4l2_ioctl_ops uvc_ioctl_ops = {
        .vidioc_querycap = uvc_ioctl_querycap,
        .vidioc_enum_fmt_vid_cap = uvc_ioctl_enum_fmt_vid_cap,
        .vidioc_enum_fmt_vid_out = uvc_ioctl_enum_fmt_vid_out,
        .vidioc_g_fmt_vid_cap = uvc_ioctl_g_fmt_vid_cap,
        .vidioc_g_fmt_vid_out = uvc_ioctl_g_fmt_vid_out,
        .vidioc_s_fmt_vid_cap = uvc_ioctl_s_fmt_vid_cap,
        .vidioc_s_fmt_vid_out = uvc_ioctl_s_fmt_vid_out,
        .vidioc_try_fmt_vid_cap = uvc_ioctl_try_fmt_vid_cap,
        .vidioc_try_fmt_vid_out = uvc_ioctl_try_fmt_vid_out,
        .vidioc_reqbufs = uvc_ioctl_reqbufs,
        .vidioc_querybuf = uvc_ioctl_querybuf,
        .vidioc_qbuf = uvc_ioctl_qbuf,
        .vidioc_expbuf = uvc_ioctl_expbuf,
        .vidioc_dqbuf = uvc_ioctl_dqbuf,
        .vidioc_create_bufs = uvc_ioctl_create_bufs,
        .vidioc_streamon = uvc_ioctl_streamon,
        .vidioc_streamoff = uvc_ioctl_streamoff,
        .vidioc_enum_input = uvc_ioctl_enum_input,
        .vidioc_g_input = uvc_ioctl_g_input,
        .vidioc_s_input = uvc_ioctl_s_input,
        .vidioc_queryctrl = uvc_ioctl_queryctrl,
        .vidioc_query_ext_ctrl = uvc_ioctl_query_ext_ctrl,
        .vidioc_g_ctrl = uvc_ioctl_g_ctrl,
        .vidioc_s_ctrl = uvc_ioctl_s_ctrl,
        .vidioc_g_ext_ctrls = uvc_ioctl_g_ext_ctrls,
        .vidioc_s_ext_ctrls = uvc_ioctl_s_ext_ctrls,
        .vidioc_try_ext_ctrls = uvc_ioctl_try_ext_ctrls,
        .vidioc_querymenu = uvc_ioctl_querymenu,
        .vidioc_g_selection = uvc_ioctl_g_selection,
        .vidioc_g_parm = uvc_ioctl_g_parm,
        .vidioc_s_parm = uvc_ioctl_s_parm,
        .vidioc_enum_framesizes = uvc_ioctl_enum_framesizes,
        .vidioc_enum_frameintervals = uvc_ioctl_enum_frameintervals,
        .vidioc_subscribe_event = uvc_ioctl_subscribe_event,
        .vidioc_unsubscribe_event = v4l2_event_unsubscribe,
        .vidioc_default = uvc_ioctl_default,
};

const struct v4l2_file_operations uvc_fops = {
        .owner          = THIS_MODULE,
        .open           = uvc_v4l2_open,
        .release        = uvc_v4l2_release,
        .unlocked_ioctl = video_ioctl2,
#ifdef CONFIG_COMPAT
        .compat_ioctl32 = uvc_v4l2_compat_ioctl32,
#endif
        .read           = uvc_v4l2_read,
        .mmap           = uvc_v4l2_mmap,
        .poll           = uvc_v4l2_poll,
#ifndef CONFIG_MMU
        .get_unmapped_area = uvc_v4l2_get_unmapped_area,
#endif
};