tty: Add carrier processing on close to the tty_port core

Some drivers implement this internally, others miss it out. Push the
behaviour into the core code as that way everyone will do it consistently.

Update the dtr rts method to raise or lower depending upon flags. Having a
single method in this style fits most of the implementations more cleanly than
two funtions.

We need this in place before we tackle the USB side

Signed-off-by: Alan Cox <alan@lxorguk.ukuu.org.uk>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

1 files changed, 2 insertions, 1 deletions

diff --git a/include/linux/tty.h b/include/linux/tty.h
index fc39db95499f..98694364c96f 100644
--- a/include/linux/tty.h
+++ b/include/linux/tty.h
@@ -185,7 +185,7 @@ struct tty_port;
 struct tty_port_operations {
         /* Return 1 if the carrier is raised */
         int (*carrier_raised)(struct tty_port *port);
-        void (*raise_dtr_rts)(struct tty_port *port);
+        void (*dtr_rts)(struct tty_port *port, int raise);
 };
         
 struct tty_port {
@@ -438,6 +438,7 @@ 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);