[PATCH] ldisc: new dcd_change() method for line disciplines.

[Rodolfo Giometti <giometti@linux.it>]

Signed-off-by: Rodolfo Giometti <giometti@linux.it>
---
 Documentation/tty.txt     |    4 ++++
 include/linux/tty_ldisc.h |   10 ++++++++++
 2 files changed, 14 insertions(+), 0 deletions(-)

diff --git a/Documentation/tty.txt b/Documentation/tty.txt
index 8e65c44..3fc812a 100644
--- a/Documentation/tty.txt
+++ b/Documentation/tty.txt
@@ -100,6 +100,10 @@ write_wakeup()	-	May be called at any point between open and close.
 			is permitted to call the driver write method from
 			this function. In such a situation defer it.
 
+dcd_change()	-	Report to the tty line the current DCD pin status
+			changes and the relative timestamp. The timestamp
+			can be NULL.
+
 
 Driver Access
 
diff --git a/include/linux/tty_ldisc.h b/include/linux/tty_ldisc.h
index 6226504..a135d6c 100644
--- a/include/linux/tty_ldisc.h
+++ b/include/linux/tty_ldisc.h
@@ -99,11 +99,19 @@
  *	cease I/O to the tty driver. Can sleep. The driver should
  *	seek to perform this action quickly but should wait until
  *	any pending driver I/O is completed.
+ *
+ * void (*dcd_change)(struct uart_port *port, unsigned int status,
+ * 			struct timespec *ts)
+ *
+ *	Tells the discipline that the DCD pin has changed its status and
+ *	the relative timestamp. Pointer ts can be NULL.
  */
 
 #include <linux/fs.h>
 #include <linux/wait.h>
 
+struct uart_port;
+
 struct tty_ldisc {
 	int	magic;
 	char	*name;
@@ -136,6 +144,8 @@ struct tty_ldisc {
 	void	(*receive_buf)(struct tty_struct *, const unsigned char *cp,
 			       char *fp, int count);
 	void	(*write_wakeup)(struct tty_struct *);
+	void	(*dcd_change)(struct uart_port *, unsigned int,
+				struct timespec *);
 
 	struct  module *owner;
 	
-- 
1.5.4.3