LinuxPPS: core support

This patch adds the kernel side of the PPS support currently named
"LinuxPPS".

PPS means "pulse per second" and a PPS source is just a device which
provides a high precision signal each second so that an application can
use it to adjust system clock time.

Common use is the combination of the NTPD as userland program with a GPS
receiver as PPS source to obtain a wallclock-time with sub-millisecond
synchronisation to UTC.

To obtain this goal the userland programs shoud use the PPS API
specification (RFC 2783 - Pulse-Per-Second API for UNIX-like Operating
Systems, Version 1.0) which in part is implemented by this patch.  It
provides a set of chars devices, one per PPS source, which can be used to
get the time signal.  The RFC's functions can be implemented by accessing
to these char devices.

Signed-off-by: Rodolfo Giometti <giometti@linux.it>
Cc: David Woodhouse <dwmw2@infradead.org>
Cc: Greg KH <greg@kroah.com>
Cc: Randy Dunlap <randy.dunlap@oracle.com>
Cc: Kay Sievers <kay.sievers@vrfy.org>
Acked-by: Alan Cox <alan@lxorguk.ukuu.org.uk>
Cc: Michael Kerrisk <mtk.manpages@googlemail.com>
Cc: Christoph Hellwig <hch@infradead.org>
Cc: Roman Zippel <zippel@linux-m68k.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

1 files changed, 7 insertions, 0 deletions

diff --git a/MAINTAINERS b/MAINTAINERS
index 5b7a08d88e4f..035df9d26609 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -4577,6 +4577,13 @@ S:	Maintained
 F:      drivers/net/pppol2tp.c
 F:      include/linux/if_pppol2tp.h
 
+PPS SUPPORT
+P:      Rodolfo Giometti
+M:      giometti@enneenne.com
+W:      http://wiki.enneenne.com/index.php/LinuxPPS_support
+L:      linuxpps@ml.enneenne.com (subscribers-only)
+S:      Maintained
+
 PREEMPTIBLE KERNEL
 P:      Robert Love
 M:      rml@tech9.net