path: root/drivers/media/video/uvc/uvc_v4l2.c

/*
 *      uvc_v4l2.c  --  USB Video Class driver - V4L2 API
 *
 *      Copyright (C) 2005-2010
 *          Laurent Pinchart (laurent.pinchart@ideasonboard.com)
 *
 *      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/slab.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 <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, int old)
{
	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:
		if (old) {
			uvc_trace(UVC_TRACE_CONTROL, "V4L2_CTRL_TYPE_MENU not "
				  "supported for UVCIOC_CTRL_MAP_OLD.\n");
			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 = -EINVAL;
		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 =