+/**
+ * tty_port_tty_get - get a tty reference
+ * @port: tty port
+ *
+ * Return a refcount protected tty instance or NULL if the port is not
+ * associated with a tty (eg due to close or hangup)
+ */
+
+struct tty_struct *tty_port_tty_get(struct tty_port *port)
+{
+ unsigned long flags;
+ struct tty_struct *tty;
+
+ spin_lock_irqsave(&port->lock, flags);
+ tty = tty_kref_get(port->tty);
+ spin_unlock_irqrestore(&port->lock, flags);
+ return tty;
+}
+EXPORT_SYMBOL(tty_port_tty_get);
+
+/**
+ * tty_port_tty_set - set the tty of a port
+ * @port: tty port
+ * @tty: the tty
+ *
+ * Associate the port and tty pair. Manages any internal refcounts.
+ * Pass NULL to deassociate a port
+ */
+
+void tty_port_tty_set(struct tty_port *port, struct tty_struct *tty)
+{
+ unsigned long flags;
+
+ spin_lock_irqsave(&port->lock, flags);
+ if (port->tty)
+ tty_kref_put(port->tty);
+ port->tty = tty;
+ spin_unlock_irqrestore(&port->lock, flags);
+}
+EXPORT_SYMBOL(tty_port_tty_set);