uvc_v4l2.c

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/*
 *      uvc_v4l2.c  --  USB Video Class driver - V4L2 API
 *
 *      Copyright (C) 2005-2010
 *          Laurent Pinchart ([email protected])
 *
 *      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/compat.h>
#include <linux/kernel.h>
#include <linux/version.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 done;
        }

        size = xmap->menu_count * sizeof(*map->menu_info);
        map->menu_info = kmalloc(size, GFP_KERNEL);
        if (map->menu_info == NULL) {
            ret = -ENOMEM;
            goto done;
        }

        if (copy_from_user(map->menu_info, xmap->menu_info, size)) {
            ret = -EFAULT;
            goto done;
        }

        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 done;
    }

    ret = uvc_ctrl_add_mapping(chain, map);

done:
    kfree(map->menu_info);
    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 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. */
    for (i = 0; i < stream->nformats; ++i) {
        format = &stream->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).
     */
    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 = 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_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 = format->bpp * frame->wWidth / 8;
    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;
    }

    memcpy(&stream->ctrl, &probe, sizeof 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)
{
    uint32_t 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;
    uint32_t interval;
    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;
    }

    memcpy(&probe, &stream->ctrl, sizeof probe);
    probe.dwFrameInterval =
        uvc_try_frame_interval(stream->cur_frame, interval);

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

    memcpy(&stream->ctrl, &probe, sizeof probe);
    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);

    if (stream->dev->state & UVC_DEV_DISCONNECTED)
        return -ENODEV;

    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;
    }

    if (atomic_inc_return(&stream->dev->users) == 1) {
        ret = uvc_status_start(stream->dev);
        if (ret < 0) {
            usb_autopm_put_interface(stream->dev->intf);
            atomic_dec(&stream->dev->users);
            kfree(handle);
            return ret;
        }
    }

    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_video_enable(stream, 0);
        uvc_free_buffers(&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;

    if (atomic_dec_return(&stream->dev->users) == 0)
        uvc_status_stop(stream->dev);

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

static long uvc_v4l2_do_ioctl(struct file *file, unsigned int cmd, void *arg)
{
    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;
    long ret = 0;

    switch (cmd) {
    /* Query capabilities */
    case VIDIOC_QUERYCAP:
    {
        struct v4l2_capability *cap = arg;

        memset(cap, 0, sizeof *cap);
        strlcpy(cap->driver, "uvcvideo", sizeof cap->driver);
        strlcpy(cap->card, vdev->name, sizeof cap->card);
        usb_make_path(stream->dev->udev,
                  cap->bus_info, sizeof(cap->bus_info));
        cap->version = LINUX_VERSION_CODE;
        if (stream->type == V4L2_BUF_TYPE_VIDEO_CAPTURE)
            cap->capabilities = V4L2_CAP_VIDEO_CAPTURE
                      | V4L2_CAP_STREAMING;
        else
            cap->capabilities = V4L2_CAP_VIDEO_OUTPUT
                      | V4L2_CAP_STREAMING;
        break;
    }

    /* Get, Set & Query control */
    case VIDIOC_QUERYCTRL:
        return uvc_query_v4l2_ctrl(chain, arg);

    case VIDIOC_G_CTRL:
    {
        struct v4l2_control *ctrl = arg;
        struct v4l2_ext_control xctrl;

        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)
            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;

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

        ret = uvc_ctrl_set(chain, &xctrl);
        if (ret < 0) {
            uvc_ctrl_rollback(handle);
            return ret;
        }
        ret = uvc_ctrl_commit(handle, &xctrl, 1);
        if (ret == 0)
            ctrl->value = xctrl.value;
        break;
    }

    case VIDIOC_QUERYMENU:
        return uvc_query_v4l2_menu(chain, arg);

    case VIDIOC_G_EXT_CTRLS:
    {
        struct v4l2_ext_controls *ctrls = arg;
        struct v4l2_ext_control *ctrl = ctrls->controls;
        unsigned int i;

        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;
        ret = uvc_ctrl_rollback(handle);
        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(chain);
        if (ret < 0)
            return ret;

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

        ctrls->error_idx = 0;

        if (cmd == VIDIOC_S_EXT_CTRLS)
            ret = uvc_ctrl_commit(handle,
                          ctrls->controls, ctrls->count);
        else
            ret = uvc_ctrl_rollback(handle);
        break;
    }

    /* Get, Set & Enum input */
    case VIDIOC_ENUMINPUT:
    {
        const struct uvc_entity *selector = chain->selector;
        struct v4l2_input *input = arg;
        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;
        strlcpy(input->name, iterm->name, sizeof input->name);
        if (UVC_ENTITY_TYPE(iterm) == UVC_ITT_CAMERA)
            input->type = V4L2_INPUT_TYPE_CAMERA;
        break;
    }

    case VIDIOC_G_INPUT:
    {
        u8 input;

        if (chain->selector == NULL ||
            (chain->dev->quirks & UVC_QUIRK_IGNORE_SELECTOR_UNIT)) {
            *(int *)arg = 0;
            break;
        }

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

        *(int *)arg = input - 1;
        break;
    }

    case VIDIOC_S_INPUT:
    {
        u32 input = *(u32 *)arg + 1;

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

        if (chain->selector == NULL ||
            (chain->dev->quirks & UVC_QUIRK_IGNORE_SELECTOR_UNIT)) {
            if (input != 1)
                return -EINVAL;
            break;
        }

        if (input == 0 || input > chain->selector->bNrInPins)
            return -EINVAL;

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

    /* Try, Get, Set & Enum format */
    case VIDIOC_ENUM_FMT:
    {
        struct v4l2_fmtdesc *fmt = arg;
        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;
        strlcpy(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;

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

    case VIDIOC_S_FMT:
        if ((ret = uvc_acquire_privileges(handle)) < 0)
            return ret;

        return uvc_v4l2_set_format(stream, arg);

    case VIDIOC_G_FMT:
        return uvc_v4l2_get_format(stream, 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 < stream->nformats; i++) {
            if (stream->format[i].fcc ==
                    fsize->pixel_format) {
                format = &stream->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 < stream->nformats; i++) {
            if (stream->format[i].fcc ==
                    fival->pixel_format) {
                format = &stream->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(stream, arg);

    case VIDIOC_S_PARM:
        if ((ret = uvc_acquire_privileges(handle)) < 0)
            return ret;

        return uvc_v4l2_set_streamparm(stream, arg);

    /* Cropping and scaling */
    case VIDIOC_CROPCAP:
    {
        struct v4l2_cropcap *ccap = arg;

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

        ccap->bounds.left = 0;
        ccap->bounds.top = 0;

        mutex_lock(&stream->mutex);
        ccap->bounds.width = stream->cur_frame->wWidth;
        ccap->bounds.height = stream->cur_frame->wHeight;
        mutex_unlock(&stream->mutex);

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

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

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

        ret = 0;
        break;

    case VIDIOC_QUERYBUF:
    {
        struct v4l2_buffer *buf = arg;

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

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

    case VIDIOC_QBUF:
        if (!uvc_has_privileges(handle))
            return -EBUSY;

        return uvc_queue_buffer(&stream->queue, arg);

    case VIDIOC_DQBUF:
        if (!uvc_has_privileges(handle))
            return -EBUSY;

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

    case VIDIOC_STREAMON:
    {
        int *type = arg;

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

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

        mutex_lock(&stream->mutex);
        ret = uvc_video_enable(stream, 1);
        mutex_unlock(&stream->mutex);
        if (ret < 0)
            return ret;
        break;
    }

    case VIDIOC_STREAMOFF:
    {
        int *type = arg;

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

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

        return uvc_video_enable(stream, 0);
    }

    case VIDIOC_SUBSCRIBE_EVENT:
    {
        struct v4l2_event_subscription *sub = arg;

        switch (sub->type) {
        case V4L2_EVENT_CTRL:
            return v4l2_event_subscribe(&handle->vfh, sub, 0,
                            &uvc_ctrl_sub_ev_ops);
        default:
            return -EINVAL;
        }
    }

    case VIDIOC_UNSUBSCRIBE_EVENT:
        return v4l2_event_unsubscribe(&handle->vfh, arg);

    case VIDIOC_DQEVENT:
        return v4l2_event_dequeue(&handle->vfh, arg,
                      file->f_flags & O_NONBLOCK);

    /* 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;

    case UVCIOC_CTRL_MAP:
        return uvc_ioctl_ctrl_map(chain, arg);

    case UVCIOC_CTRL_QUERY:
        return uvc_xu_ctrl_query(chain, arg);

    default:
        uvc_trace(UVC_TRACE_IOCTL, "Unknown ioctl 0x%08x\n", cmd);
        return -ENOTTY;
    }

    return ret;
}

static long uvc_v4l2_ioctl(struct file *file,
             unsigned int cmd, unsigned long arg)
{
    if (uvc_trace_param & UVC_TRACE_IOCTL) {
        uvc_printk(KERN_DEBUG, "uvc_v4l2_ioctl(");
        v4l_printk_ioctl(NULL, cmd);
        printk(")\n");
    }

    return video_usercopy(file, cmd, arg, uvc_v4l2_do_ioctl);
}

#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_menu_info __user *umenus;
    struct uvc_menu_info __user *kmenus;
    compat_caddr_t p;

    if (!access_ok(VERIFY_READ, up, sizeof(*up)) ||
        __copy_from_user(kp, up, offsetof(typeof(*up), menu_info)) ||
        __get_user(kp->menu_count, &up->menu_count))
        return -EFAULT;

    memset(kp->reserved, 0, sizeof(kp->reserved));

    if (kp->menu_count == 0) {
        kp->menu_info = NULL;
        return 0;
    }

    if (__get_user(p, &up->menu_info))
        return -EFAULT;
    umenus = compat_ptr(p);
    if (!access_ok(VERIFY_READ, umenus, kp->menu_count * sizeof(*umenus)))
        return -EFAULT;

    kmenus = compat_alloc_user_space(kp->menu_count * sizeof(*kmenus));
    if (kmenus == NULL)
        return -EFAULT;
    kp->menu_info = kmenus;

    if (copy_in_user(kmenus, umenus, kp->menu_count * sizeof(*umenus)))
        return -EFAULT;

    return 0;
}

static int uvc_v4l2_put_xu_mapping(const struct uvc_xu_control_mapping *kp,
            struct uvc_xu_control_mapping32 __user *up)
{
    struct uvc_menu_info __user *umenus;
    struct uvc_menu_info __user *kmenus = kp->menu_info;
    compat_caddr_t p;

    if (!access_ok(VERIFY_WRITE, up, sizeof(*up)) ||
        __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;

    if (kp->menu_count == 0)
        return 0;

    if (get_user(p, &up->menu_info))
        return -EFAULT;
    umenus = compat_ptr(p);

    if (copy_in_user(umenus, kmenus, kp->menu_count * sizeof(*umenus)))
        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)
{
    u8 __user *udata;
    u8 __user *kdata;
    compat_caddr_t p;

    if (!access_ok(VERIFY_READ, up, sizeof(*up)) ||
        __copy_from_user(kp, up, offsetof(typeof(*up), data)))
        return -EFAULT;

    if (kp->size == 0) {
        kp->data = NULL;
        return 0;
    }

    if (__get_user(p, &up->data))
        return -EFAULT;
    udata = compat_ptr(p);
    if (!access_ok(VERIFY_READ, udata, kp->size))
        return -EFAULT;

    kdata = compat_alloc_user_space(kp->size);
    if (kdata == NULL)
        return -EFAULT;
    kp->data = kdata;

    if (copy_in_user(kdata, udata, kp->size))
        return -EFAULT;

    return 0;
}

static int uvc_v4l2_put_xu_query(const struct uvc_xu_control_query *kp,
            struct uvc_xu_control_query32 __user *up)
{
    u8 __user *udata;
    u8 __user *kdata = kp->data;
    compat_caddr_t p;

    if (!access_ok(VERIFY_WRITE, up, sizeof(*up)) ||
        __copy_to_user(up, kp, offsetof(typeof(*up), data)))
        return -EFAULT;

    if (kp->size == 0)
        return 0;

    if (get_user(p, &up->data))
        return -EFAULT;
    udata = compat_ptr(p);
    if (!access_ok(VERIFY_READ, udata, kp->size))
        return -EFAULT;

    if (copy_in_user(udata, kdata, kp->size))
        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)
{
    union {
        struct uvc_xu_control_mapping xmap;
        struct uvc_xu_control_query xqry;
    } karg;
    void __user *up = compat_ptr(arg);
    mm_segment_t old_fs;
    long ret;

    switch (cmd) {
    case UVCIOC_CTRL_MAP32:
        cmd = UVCIOC_CTRL_MAP;
        ret = uvc_v4l2_get_xu_mapping(&karg.xmap, up);
        break;

    case UVCIOC_CTRL_QUERY32:
        cmd = UVCIOC_CTRL_QUERY;
        ret = uvc_v4l2_get_xu_query(&karg.xqry, up);
        break;

    default:
        return -ENOIOCTLCMD;
    }

    old_fs = get_fs();
    set_fs(KERNEL_DS);
    ret = uvc_v4l2_ioctl(file, cmd, (unsigned long)&karg);
    set_fs(old_fs);

    if (ret < 0)
        return ret;

    switch (cmd) {
    case UVCIOC_CTRL_MAP:
        ret = uvc_v4l2_put_xu_mapping(&karg.xmap, up);
        break;

    case UVCIOC_CTRL_QUERY:
        ret = uvc_v4l2_put_xu_query(&karg.xqry, up);
        break;
    }

    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 unsigned int 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_file_operations uvc_fops = {
    .owner      = THIS_MODULE,
    .open       = uvc_v4l2_open,
    .release    = uvc_v4l2_release,
    .unlocked_ioctl = uvc_v4l2_ioctl,
#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
};