static int vidioc_queryctrl(struct file *file, void *fh, struct v4l2_queryctrl *c)
{
	const struct v4l2_queryctrl *ctrl;

	if ((c->id <  V4L2_CID_BASE ||
	     c->id >= V4L2_CID_LASTP1) &&
	    (c->id <  V4L2_CID_PRIVATE_BASE ||
	     c->id >= V4L2_CID_PRIVATE_LASTP1))
		return -EINVAL;

	ctrl = ctrl_by_id(c->id);
	if (ctrl == NULL)
		return -EINVAL;

	DEB_EE("VIDIOC_QUERYCTRL: id:%d\n", c->id);
	*c = *ctrl;
	return 0;
}
static int get_control(struct saa7146_fh *fh, struct v4l2_control *c)
{
	struct saa7146_dev *dev = fh->dev;
	struct saa7146_vv *vv = dev->vv_data;

	const struct v4l2_queryctrl* ctrl;
	u32 value = 0;

	ctrl = ctrl_by_id(c->id);
	if (NULL == ctrl)
		return -EINVAL;
	switch (c->id) {
	case V4L2_CID_BRIGHTNESS:
		value = saa7146_read(dev, BCS_CTRL);
		c->value = 0xff & (value >> 24);
		DEB_D(("V4L2_CID_BRIGHTNESS: %d\n",c->value));
		break;
	case V4L2_CID_CONTRAST:
		value = saa7146_read(dev, BCS_CTRL);
		c->value = 0x7f & (value >> 16);
		DEB_D(("V4L2_CID_CONTRAST: %d\n",c->value));
		break;
	case V4L2_CID_SATURATION:
		value = saa7146_read(dev, BCS_CTRL);
		c->value = 0x7f & (value >> 0);
		DEB_D(("V4L2_CID_SATURATION: %d\n",c->value));
		break;
	case V4L2_CID_VFLIP:
		c->value = vv->vflip;
		DEB_D(("V4L2_CID_VFLIP: %d\n",c->value));
		break;
	case V4L2_CID_HFLIP:
		c->value = vv->hflip;
		DEB_D(("V4L2_CID_HFLIP: %d\n",c->value));
		break;
	default:
		return -EINVAL;
	}

	return 0;
}
int saa7146_video_do_ioctl(struct inode *inode, struct file *file, unsigned int cmd, void *arg)
{
	struct saa7146_fh *fh  = file->private_data;
	struct saa7146_dev *dev = fh->dev;
	struct saa7146_vv *vv = dev->vv_data;

	int err = 0, result = 0, ee = 0;

	struct saa7146_use_ops *ops;
	struct videobuf_queue *q;

	/* check if extension handles the command */
	for(ee = 0; dev->ext_vv_data->ioctls[ee].flags != 0; ee++) {
		if( cmd == dev->ext_vv_data->ioctls[ee].cmd )
			break;
	}

	if( 0 != (dev->ext_vv_data->ioctls[ee].flags & SAA7146_EXCLUSIVE) ) {
		DEB_D(("extension handles ioctl exclusive.\n"));
		result = dev->ext_vv_data->ioctl(fh, cmd, arg);
		return result;
	}
	if( 0 != (dev->ext_vv_data->ioctls[ee].flags & SAA7146_BEFORE) ) {
		DEB_D(("extension handles ioctl before.\n"));
		result = dev->ext_vv_data->ioctl(fh, cmd, arg);
		if( -EAGAIN != result ) {
			return result;
		}
	}

	/* fixme: add handle "after" case (is it still needed?) */

	switch (fh->type) {
	case V4L2_BUF_TYPE_VIDEO_CAPTURE: {
		ops = &saa7146_video_uops;
		q = &fh->video_q;
		break;
		}
	case V4L2_BUF_TYPE_VBI_CAPTURE: {
		ops = &saa7146_vbi_uops;
		q = &fh->vbi_q;
		break;
		}
	default:
		BUG();
		return 0;
	}

	switch (cmd) {
	case VIDIOC_QUERYCAP:
	{
		struct v4l2_capability *cap = arg;
		memset(cap,0,sizeof(*cap));

		DEB_EE(("VIDIOC_QUERYCAP\n"));

		strcpy(cap->driver, "saa7146 v4l2");
		strlcpy(cap->card, dev->ext->name, sizeof(cap->card));
		sprintf(cap->bus_info,"PCI:%s", pci_name(dev->pci));
		cap->version = SAA7146_VERSION_CODE;
		cap->capabilities =
			V4L2_CAP_VIDEO_CAPTURE |
			V4L2_CAP_VIDEO_OVERLAY |
			V4L2_CAP_READWRITE |
			V4L2_CAP_STREAMING;
		cap->capabilities |= dev->ext_vv_data->capabilities;
		return 0;
	}
	case VIDIOC_G_FBUF:
	{
		struct v4l2_framebuffer *fb = arg;

		DEB_EE(("VIDIOC_G_FBUF\n"));

		*fb = vv->ov_fb;
		fb->capability = V4L2_FBUF_CAP_LIST_CLIPPING;
		return 0;
	}
	case VIDIOC_S_FBUF:
	{
		struct v4l2_framebuffer *fb = arg;
		struct saa7146_format *fmt;

		DEB_EE(("VIDIOC_S_FBUF\n"));

		if(!capable(CAP_SYS_ADMIN) &&
		   !capable(CAP_SYS_RAWIO))
			return -EPERM;

		/* check args */
		fmt = format_by_fourcc(dev,fb->fmt.pixelformat);
		if (NULL == fmt) {
			return -EINVAL;
		}

		/* planar formats are not allowed for overlay video, clipping and video dma would clash */
		if (0 != (fmt->flags & FORMAT_IS_PLANAR)) {
			DEB_S(("planar pixelformat '%4.4s' not allowed for overlay\n",(char *)&fmt->pixelformat));
		}

		/* check if overlay is running */
		if (IS_OVERLAY_ACTIVE(fh) != 0) {
			if (vv->video_fh != fh) {
				DEB_D(("refusing to change framebuffer informations while overlay is active in another open.\n"));
				return -EBUSY;
			}
		}

		down(&dev->lock);

		/* ok, accept it */
		vv->ov_fb = *fb;
		vv->ov_fmt = fmt;
		if (0 == vv->ov_fb.fmt.bytesperline)
			vv->ov_fb.fmt.bytesperline =
				vv->ov_fb.fmt.width*fmt->depth/8;

		up(&dev->lock);

		return 0;
	}
	case VIDIOC_ENUM_FMT:
	{
		struct v4l2_fmtdesc *f = arg;
		int index;

		switch (f->type) {
		case V4L2_BUF_TYPE_VIDEO_CAPTURE:
		case V4L2_BUF_TYPE_VIDEO_OVERLAY: {
			index = f->index;
			if (index < 0 || index >= NUM_FORMATS) {
				return -EINVAL;
			}
			memset(f,0,sizeof(*f));
			f->index = index;
			strlcpy(f->description,formats[index].name,sizeof(f->description));
			f->pixelformat = formats[index].pixelformat;
			break;
		}
		default:
			return -EINVAL;
		}

		DEB_EE(("VIDIOC_ENUM_FMT: type:%d, index:%d\n",f->type,f->index));
		return 0;
	}
	case VIDIOC_QUERYCTRL:
	{
		const struct v4l2_queryctrl *ctrl;
		struct v4l2_queryctrl *c = arg;

		if ((c->id <  V4L2_CID_BASE ||
		     c->id >= V4L2_CID_LASTP1) &&
		    (c->id <  V4L2_CID_PRIVATE_BASE ||
		     c->id >= V4L2_CID_PRIVATE_LASTP1))
			return -EINVAL;

		ctrl = ctrl_by_id(c->id);
		if( NULL == ctrl ) {
			return -EINVAL;
/*
			c->flags = V4L2_CTRL_FLAG_DISABLED;
			return 0;
*/
		}

		DEB_EE(("VIDIOC_QUERYCTRL: id:%d\n",c->id));
		*c = *ctrl;
		return 0;
	}
	case VIDIOC_G_CTRL: {
		DEB_EE(("VIDIOC_G_CTRL\n"));
		return get_control(fh,arg);
	}
	case VIDIOC_S_CTRL:
	{
		DEB_EE(("VIDIOC_S_CTRL\n"));
		err = set_control(fh,arg);
		return err;
	}
	case VIDIOC_G_PARM:
	{
		struct v4l2_streamparm *parm = arg;
		if( parm->type != V4L2_BUF_TYPE_VIDEO_CAPTURE ) {
			return -EINVAL;
		}
		memset(&parm->parm.capture,0,sizeof(struct v4l2_captureparm));
		parm->parm.capture.readbuffers = 1;
		// fixme: only for PAL!
		parm->parm.capture.timeperframe.numerator = 1;
		parm->parm.capture.timeperframe.denominator = 25;
		return 0;
	}
	case VIDIOC_G_FMT:
	{
		struct v4l2_format *f = arg;
		DEB_EE(("VIDIOC_G_FMT\n"));
		return g_fmt(fh,f);
	}
	case VIDIOC_S_FMT:
	{
		struct v4l2_format *f = arg;
		DEB_EE(("VIDIOC_S_FMT\n"));
		return s_fmt(fh,f);
	}
	case VIDIOC_TRY_FMT:
	{
		struct v4l2_format *f = arg;
		DEB_EE(("VIDIOC_TRY_FMT\n"));
		return try_fmt(fh,f);
	}
	case VIDIOC_G_STD:
	{
		v4l2_std_id *id = arg;
		DEB_EE(("VIDIOC_G_STD\n"));
		*id = vv->standard->id;
		return 0;
	}
	/* the saa7146 supfhrts (used in conjunction with the saa7111a for example)
	   PAL / NTSC / SECAM. if your hardware does not (or does more)
	   -- override this function in your extension */
	case VIDIOC_ENUMSTD:
	{
		struct v4l2_standard *e = arg;
		if (e->index < 0 )
			return -EINVAL;
		if( e->index < dev->ext_vv_data->num_stds ) {
			DEB_EE(("VIDIOC_ENUMSTD: index:%d\n",e->index));
			v4l2_video_std_construct(e, dev->ext_vv_data->stds[e->index].id, dev->ext_vv_data->stds[e->index].name);
			return 0;
		}
		return -EINVAL;
	}
	case VIDIOC_S_STD:
	{
		v4l2_std_id *id = arg;
		int found = 0;
		int i, err;

		DEB_EE(("VIDIOC_S_STD\n"));

		if ((vv->video_status & STATUS_CAPTURE) == STATUS_CAPTURE) {
			DEB_D(("cannot change video standard while streaming capture is active\n"));
			return -EBUSY;
		}

		if ((vv->video_status & STATUS_OVERLAY) != 0) {
			vv->ov_suspend = vv->video_fh;
			err = saa7146_stop_preview(vv->video_fh); /* side effect: video_status is now 0, video_fh is NULL */
			if (0 != err) {
				DEB_D(("suspending video failed. aborting\n"));
				return err;
			}
		}

		down(&dev->lock);

		for(i = 0; i < dev->ext_vv_data->num_stds; i++)
			if (*id & dev->ext_vv_data->stds[i].id)
				break;
		if (i != dev->ext_vv_data->num_stds) {
			vv->standard = &dev->ext_vv_data->stds[i];
			if( NULL != dev->ext_vv_data->std_callback )
				dev->ext_vv_data->std_callback(dev, vv->standard);
			found = 1;
		}

		up(&dev->lock);

		if (vv->ov_suspend != NULL) {
			saa7146_start_preview(vv->ov_suspend);
			vv->ov_suspend = NULL;
		}

		if( 0 == found ) {
			DEB_EE(("VIDIOC_S_STD: standard not found.\n"));
			return -EINVAL;
		}

		DEB_EE(("VIDIOC_S_STD: set to standard to '%s'\n",vv->standard->name));
		return 0;
	}
	case VIDIOC_OVERLAY:




	{
		int on = *(int *)arg;
		int err = 0;

		DEB_D(("VIDIOC_OVERLAY on:%d\n",on));
		if (on != 0) {
			err = saa7146_start_preview(fh);
		} else {
			err = saa7146_stop_preview(fh);
		}
		return err;
	}
	case VIDIOC_REQBUFS: {
		struct v4l2_requestbuffers *req = arg;
		DEB_D(("VIDIOC_REQBUFS, type:%d\n",req->type));
		return videobuf_reqbufs(q,req);
	}
	case VIDIOC_QUERYBUF: {
		struct v4l2_buffer *buf = arg;
		DEB_D(("VIDIOC_QUERYBUF, type:%d, offset:%d\n",buf->type,buf->m.offset));
		return videobuf_querybuf(q,buf);
	}
	case VIDIOC_QBUF: {
		struct v4l2_buffer *buf = arg;
		int ret = 0;
		ret = videobuf_qbuf(q,buf);
		DEB_D(("VIDIOC_QBUF: ret:%d, index:%d\n",ret,buf->index));
		return ret;
	}
	case VIDIOC_DQBUF: {
		struct v4l2_buffer *buf = arg;
		int ret = 0;
		ret = videobuf_dqbuf(q,buf,file->f_flags & O_NONBLOCK);
		DEB_D(("VIDIOC_DQBUF: ret:%d, index:%d\n",ret,buf->index));
		return ret;
	}
	case VIDIOC_STREAMON: {
		int *type = arg;
		DEB_D(("VIDIOC_STREAMON, type:%d\n",*type));

		err = video_begin(fh);
		if( 0 != err) {
			return err;
		}
		err = videobuf_streamon(q);
		return err;
	}
	case VIDIOC_STREAMOFF: {
		int *type = arg;

		DEB_D(("VIDIOC_STREAMOFF, type:%d\n",*type));

		/* ugly: we need to copy some checks from video_end(),
		   because videobuf_streamoff() relies on the capture running.
		   check and fix this */
		if ((vv->video_status & STATUS_CAPTURE) != STATUS_CAPTURE) {
			DEB_S(("not capturing.\n"));
			return 0;
		}

		if (vv->video_fh != fh) {
			DEB_S(("capturing, but in another open.\n"));
			return -EBUSY;
		}

		err = videobuf_streamoff(q);
		if (0 != err) {
			DEB_D(("warning: videobuf_streamoff() failed.\n"));
			video_end(fh, file);
		} else {
			err = video_end(fh, file);
		}
		return err;
	}
	case VIDIOCGMBUF:
	{
		struct video_mbuf *mbuf = arg;
		struct videobuf_queue *q;
		int i;

		/* fixme: number of capture buffers and sizes for v4l apps */
		int gbuffers = 2;
		int gbufsize = 768*576*4;

		DEB_D(("VIDIOCGMBUF \n"));

		q = &fh->video_q;
		down(&q->lock);
		err = videobuf_mmap_setup(q,gbuffers,gbufsize,
					  V4L2_MEMORY_MMAP);
		if (err < 0) {
			up(&q->lock);
			return err;
		}
		memset(mbuf,0,sizeof(*mbuf));
		mbuf->frames = gbuffers;
		mbuf->size   = gbuffers * gbufsize;
		for (i = 0; i < gbuffers; i++)
			mbuf->offsets[i] = i * gbufsize;
		up(&q->lock);
		return 0;
	}
	default:
		return v4l_compat_translate_ioctl(inode,file,cmd,arg,
						  saa7146_video_do_ioctl);
	}
	return 0;
}
static int set_control(struct saa7146_fh *fh, struct v4l2_control *c)
{
	struct saa7146_dev *dev = fh->dev;
	struct saa7146_vv *vv = dev->vv_data;

	const struct v4l2_queryctrl* ctrl;

	ctrl = ctrl_by_id(c->id);
	if (NULL == ctrl) {
		DEB_D(("unknown control %d\n",c->id));
		return -EINVAL;
	}

	down(&dev->lock);

	switch (ctrl->type) {
	case V4L2_CTRL_TYPE_BOOLEAN:
	case V4L2_CTRL_TYPE_MENU:
	case V4L2_CTRL_TYPE_INTEGER:
		if (c->value < ctrl->minimum)
			c->value = ctrl->minimum;
		if (c->value > ctrl->maximum)
			c->value = ctrl->maximum;
		break;
	default:
		/* nothing */;
	};

	switch (c->id) {
	case V4L2_CID_BRIGHTNESS: {
		u32 value = saa7146_read(dev, BCS_CTRL);
		value &= 0x00ffffff;
		value |= (c->value << 24);
		saa7146_write(dev, BCS_CTRL, value);
		saa7146_write(dev, MC2, MASK_22 | MASK_06 );
		break;
	}
	case V4L2_CID_CONTRAST: {
		u32 value = saa7146_read(dev, BCS_CTRL);
		value &= 0xff00ffff;
		value |= (c->value << 16);
		saa7146_write(dev, BCS_CTRL, value);
		saa7146_write(dev, MC2, MASK_22 | MASK_06 );
		break;
	}
	case V4L2_CID_SATURATION: {
		u32 value = saa7146_read(dev, BCS_CTRL);
		value &= 0xffffff00;
		value |= (c->value << 0);
		saa7146_write(dev, BCS_CTRL, value);
		saa7146_write(dev, MC2, MASK_22 | MASK_06 );
		break;
	}
	case V4L2_CID_HFLIP:
		/* fixme: we can support changing VFLIP and HFLIP here... */
		if (IS_CAPTURE_ACTIVE(fh) != 0) {
			DEB_D(("V4L2_CID_HFLIP while active capture.\n"));
			up(&dev->lock);
			return -EINVAL;
		}
		vv->hflip = c->value;
		break;
	case V4L2_CID_VFLIP:
		if (IS_CAPTURE_ACTIVE(fh) != 0) {
			DEB_D(("V4L2_CID_VFLIP while active capture.\n"));
			up(&dev->lock);
			return -EINVAL;
		}
		vv->vflip = c->value;
		break;
	default: {
		return -EINVAL;
	}
	}
	up(&dev->lock);

	if (IS_OVERLAY_ACTIVE(fh) != 0) {
		saa7146_stop_preview(fh);
		saa7146_start_preview(fh);
	}
	return 0;
}