tty_port: Add a port level carrier detect operation
This is the first step to generalising the various pieces of waiting logic
duplicated in all sorts of serial drivers.
Signed-off-by: Alan Cox <alan@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/include/linux/tty.h b/include/linux/tty.h
index bbbeaef..bc7bae7 100644
--- a/include/linux/tty.h
+++ b/include/linux/tty.h
@@ -180,8 +180,16 @@
* until a hangup so don't use the wrong path.
*/
+struct tty_port;
+
+struct tty_port_operations {
+ /* Return 1 if the carrier is raised */
+ int (*carrier_raised)(struct tty_port *port);
+};
+
struct tty_port {
struct tty_struct *tty; /* Back pointer */
+ const struct tty_port_operations *ops; /* Port operations */
spinlock_t lock; /* Lock protecting tty field */
int blocked_open; /* Waiting to open */
int count; /* Usage count */
@@ -427,6 +435,7 @@
extern void tty_port_free_xmit_buf(struct tty_port *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 int tty_register_ldisc(int disc, struct tty_ldisc_ops *new_ldisc);
extern int tty_unregister_ldisc(int disc);