#define EVIOCGEFFECTS _IOR('E', 0x84, int) /* Report number of effects playable at the same time */
#define EVIOCGRAB _IOW('E', 0x90, int) /* Grab/Release device */
+#define EVIOCREVOKE _IOW('E', 0x91, int) /* Revoke device access */
#define EVIOCSCLOCKID _IOW('E', 0xa0, int) /* Set clockid to be used for timestamps */