1 files changed, 2 insertions, 0 deletions

diff --git a/include/linux/libps2.h b/include/linux/libps2.h
index afc413369101..b94534b7e266 100644
--- a/include/linux/libps2.h
+++ b/include/linux/libps2.h
@@ -18,11 +18,13 @@
 #define PS2_RET_ID              0x00
 #define PS2_RET_ACK             0xfa
 #define PS2_RET_NAK             0xfe
+#define PS2_RET_ERR             0xfc
 
 #define PS2_FLAG_ACK            1       /* Waiting for ACK/NAK */
 #define PS2_FLAG_CMD            2       /* Waiting for command to finish */
 #define PS2_FLAG_CMD1           4       /* Waiting for the first byte of command response */
 #define PS2_FLAG_WAITID         8       /* Command execiting is GET ID */
+#define PS2_FLAG_NAK            16      /* Last transmission was NAKed */
 
 struct ps2dev {
         struct serio *serio;