+extern void tty_port_put(struct tty_port *port);
+
+static inline struct tty_port *tty_port_get(struct tty_port *port)
+{
+ if (port)
+ kref_get(&port->kref);
+ return port;
+}
+
+extern struct tty_struct *tty_port_tty_get(struct tty_port *port);
+extern void tty_port_tty_set(struct tty_port *port, struct tty_struct *tty);
+extern int tty_port_carrier_raised(struct tty_port *port);
+extern void tty_port_raise_dtr_rts(struct tty_port *port);
+extern void tty_port_lower_dtr_rts(struct tty_port *port);
+extern void tty_port_hangup(struct tty_port *port);
+extern int tty_port_block_til_ready(struct tty_port *port,
+ struct tty_struct *tty, struct file *filp);
+extern int tty_port_close_start(struct tty_port *port,
+ struct tty_struct *tty, struct file *filp);
+extern void tty_port_close_end(struct tty_port *port, struct tty_struct *tty);
+extern void tty_port_close(struct tty_port *port,
+ struct tty_struct *tty, struct file *filp);
+extern int tty_port_open(struct tty_port *port,
+ struct tty_struct *tty, struct file *filp);
+static inline int tty_port_users(struct tty_port *port)
+{
+ return port->count + port->blocked_open;
+}