#define PHN_SET_REG _IOW (PH_IOC_MAGIC, 1, struct phm_reg *)
#define PHN_GET_REGS _IOWR(PH_IOC_MAGIC, 2, struct phm_regs *)
#define PHN_SET_REGS _IOW (PH_IOC_MAGIC, 3, struct phm_regs *)
-#define PH_IOC_MAXNR 3
+/* this ioctl tells the driver, that the caller is not OpenHaptics and might
+ * use improved registers update (no more phantom switchoffs when using
+ * libphantom) */
+#define PHN_NOT_OH _IO (PH_IOC_MAGIC, 4)
+#define PH_IOC_MAXNR 4
#define PHN_CONTROL 0x6 /* control byte in iaddr space */
#define PHN_CTL_AMP 0x1 /* switch after torques change */