pps: Move timestamp read into PPS code proper

The PPS (Pulse-Per-Second) line discipline has developed a number of
unhealthy attachments to core tty data and functions, ultimately leading
to its breakage.

The previous patches fixed the crashing.  This one reduces coupling further
by eliminating the timestamp parameter from the dcd_change ldisc method.
This reduces header file linkage and makes the extension more generic,
and the timestamp read is delayed only slightly, from just before the
ldisc->ops->dcd_change method call to just after.

Fix attendant build breakage in
    drivers/tty/n_tty.c
    drivers/tty/tty_buffer.c
    drivers/staging/speakup/selection.c
    drivers/staging/dgrp/dgrp_*.c

Cc: William Hubbs <w.d.hubbs@gmail.com>
Cc: Chris Brannon <chris@the-brannons.com>
Cc: Kirk Reiser <kirk@braille.uwo.ca>
Cc: Samuel Thibault <samuel.thibault@ens-lyon.org>
Signed-off-by: Peter Hurley <peter@hurleysoftware.com>
Signed-off-by: George Spelvin <linux@horizon.com>
Acked-by: Rodolfo Giometti <giometti@enneenne.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

1 files changed, 4 insertions, 7 deletions

diff --git a/include/linux/tty_ldisc.h b/include/linux/tty_ldisc.h
index fb79dd8d1537..455a0d7bf220 100644
--- a/include/linux/tty_ldisc.h
+++ b/include/linux/tty_ldisc.h
@@ -100,16 +100,14 @@
  *      seek to perform this action quickly but should wait until
  *      any pending driver I/O is completed.
  *
- * void (*dcd_change)(struct tty_struct *tty, unsigned int status,
- *                      struct pps_event_time *ts)
+ * void (*dcd_change)(struct tty_struct *tty, unsigned int status)
  *
- *      Tells the discipline that the DCD pin has changed its status and
- *      the relative timestamp. Pointer ts cannot be NULL.
+ *      Tells the discipline that the DCD pin has changed its status.
+ *      Used exclusively by the N_PPS (Pulse-Per-Second) line discipline.
  */
 
 #include <linux/fs.h>
 #include <linux/wait.h>
-#include <linux/pps_kernel.h>
 #include <linux/wait.h>
 
 struct tty_ldisc_ops {
@@ -144,8 +142,7 @@ struct tty_ldisc_ops {
         void    (*receive_buf)(struct tty_struct *, const unsigned char *cp,
                                char *fp, int count);
         void    (*write_wakeup)(struct tty_struct *);
-        void    (*dcd_change)(struct tty_struct *, unsigned int,
-                                struct pps_event_time *);
+        void    (*dcd_change)(struct tty_struct *, unsigned int);
 
         struct  module *owner;