tty: Make tiocgicount a handler

Dan Rosenberg noted that various drivers return the struct with uncleared
fields. Instead of spending forever trying to stomp all the drivers that
get it wrong (and every new driver) do the job in one place.

This first patch adds the needed operations and hooks them up, including
the needed USB midlayer and serial core plumbing.

Signed-off-by: Alan Cox <alan@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

1 files changed, 13 insertions, 0 deletions

diff --git a/drivers/usb/serial/usb-serial.c b/drivers/usb/serial/usb-serial.c
index 7a2177c79bde..e64da74bdcc5 100644
--- a/drivers/usb/serial/usb-serial.c
+++ b/drivers/usb/serial/usb-serial.c
@@ -519,6 +519,18 @@ static int serial_tiocmset(struct tty_struct *tty, struct file *file,
         return -EINVAL;
 }
 
+static int serial_get_icount(struct tty_struct *tty,
+                                struct serial_icounter_struct *icount)
+{
+        struct usb_serial_port *port = tty->driver_data;
+
+        dbg("%s - port %d", __func__, port->number);
+
+        if (port->serial->type->get_icount)
+                return port->serial->type->get_icount(tty, icount);
+        return -EINVAL;
+}
+
 /*
  * We would be calling tty_wakeup here, but unfortunately some line
  * disciplines have an annoying habit of calling tty->write from
@@ -1195,6 +1207,7 @@ static const struct tty_operations serial_ops = {
         .chars_in_buffer =      serial_chars_in_buffer,
         .tiocmget =             serial_tiocmget,
         .tiocmset =             serial_tiocmset,
+        .get_icount =           serial_get_icount,
         .cleanup =              serial_cleanup,
         .install =              serial_install,
         .proc_fops =            &serial_proc_fops,