diff --git a/drivers/hid/hid-wiimote.h b/drivers/hid/hid-wiimote.h
index 0afc9f9..8d314ae 100644
--- a/drivers/hid/hid-wiimote.h
+++ b/drivers/hid/hid-wiimote.h
@@ -73,12 +73,14 @@
 	WIIMOTE_DEV_GENERIC,
 	WIIMOTE_DEV_GEN10,
 	WIIMOTE_DEV_GEN20,
+	WIIMOTE_DEV_BALANCE_BOARD,
 	WIIMOTE_DEV_NUM,
 };
 
 enum wiimote_exttype {
 	WIIMOTE_EXT_NONE,
 	WIIMOTE_EXT_UNKNOWN,
+	WIIMOTE_EXT_BALANCE_BOARD,
 	WIIMOTE_EXT_NUM,
 };
 
@@ -123,6 +125,9 @@
 	__u8 cmd_err;
 	__u8 *cmd_read_buf;
 	__u8 cmd_read_size;
+
+	/* calibration data */
+	__u16 calib_bboard[4][3];
 };
 
 struct wiimote_data {
@@ -136,6 +141,10 @@
 	struct wiimote_ext *ext;
 	struct wiimote_debug *debug;
 
+	union {
+		struct input_dev *input;
+	} extension;
+
 	struct wiimote_queue queue;
 	struct wiimote_state state;
 	struct work_struct init_worker;