V4L/DVB (8498): uvcvideo: Return sensible min and max values when querying a boolean control.

commit 54812c77 upstream

[required to get the following two patches to apply]

Although the V4L2 spec states that the minimum and maximum fields may not be
valid for control types other than V4L2_CTRL_TYPE_INTEGER, it makes sense
to set the bounds to 0 and 1 for boolean controls instead of returning
uninitialized values.
Signed-off-by: Laurent Pinchart <laurent.pinchart@skynet.be>
Signed-off-by: Mauro Carvalho Chehab <mchehab@infradead.org>
Cc: Chuck Ebbert <cebbert@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

drivers/media/video/uvc/uvc_ctrl.c

@@ -592,6 +592,7 @@ int uvc_query_v4l2_ctrl(struct uvc_video_device *video,
 	if (ctrl == NULL)
 		return -EINVAL;
 
+	memset(v4l2_ctrl, 0, sizeof *v4l2_ctrl);
 	v4l2_ctrl->id = mapping->id;
 	v4l2_ctrl->type = mapping->v4l2_type;
 	strncpy(v4l2_ctrl->name, mapping->name, sizeof v4l2_ctrl->name);
@@ -608,7 +609,8 @@ int uvc_query_v4l2_ctrl(struct uvc_video_device *video,
 		v4l2_ctrl->default_value = uvc_get_le_value(data, mapping);
 	}
 
-	if (mapping->v4l2_type == V4L2_CTRL_TYPE_MENU) {
+	switch (mapping->v4l2_type) {
+	case V4L2_CTRL_TYPE_MENU:
 		v4l2_ctrl->minimum = 0;
 		v4l2_ctrl->maximum = mapping->menu_count - 1;
 		v4l2_ctrl->step = 1;
@@ -622,6 +624,15 @@ int uvc_query_v4l2_ctrl(struct uvc_video_device *video,
 		}
 
 		return 0;
+
+	case V4L2_CTRL_TYPE_BOOLEAN:
+		v4l2_ctrl->minimum = 0;
+		v4l2_ctrl->maximum = 1;
+		v4l2_ctrl->step = 1;
+		return 0;
+
+	default:
+		break;
 	}
 
 	if (ctrl->info->flags & UVC_CONTROL_GET_MIN) {