#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;