TTY: add tty_port_register_device helper

This will automatically assign tty_port to tty_driver's port array for
later recall in tty_init_dev. This is intended to be called instead of
tty_register_device.

Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/tty/tty_port.c

@@ -33,6 +33,15 @@ void tty_port_init(struct tty_port *port)
 }
 EXPORT_SYMBOL(tty_port_init);
 
+struct device *tty_port_register_device(struct tty_port *port,
+		struct tty_driver *driver, unsigned index,
+		struct device *device)
+{
+	driver->ports[index] = port;
+	return tty_register_device(driver, index, device);
+}
+EXPORT_SYMBOL_GPL(tty_port_register_device);
+
 int tty_port_alloc_xmit_buf(struct tty_port *port)
 {
 	/* We may sleep in get_zeroed_page() */

include/linux/tty.h

@@ -497,6 +497,9 @@ extern int tty_write_lock(struct tty_struct *tty, int ndelay);
 #define tty_is_writelocked(tty)  (mutex_is_locked(&tty->atomic_write_lock))
 
 extern void tty_port_init(struct tty_port *port);
+extern struct device *tty_port_register_device(struct tty_port *port,
+		struct tty_driver *driver, unsigned index,
+		struct device *device);
 extern int tty_port_alloc_xmit_buf(struct tty_port *port);
 extern void tty_port_free_xmit_buf(struct tty_port *port);
 extern void tty_port_put(struct tty_port *port);