+ tty->driver_data = NULL;
+ tty_port_tty_set(&ch->port, NULL);
+}
+
+static int moxa_carrier_raised(struct tty_port *port)
+{
+ struct moxa_port *ch = container_of(port, struct moxa_port, port);
+ int dcd;
+
+ spin_lock_bh(&moxa_lock);
+ dcd = ch->DCDState;
+ spin_unlock_bh(&moxa_lock);
+ return dcd;