14 Jan, 2011

2 commits

  • Add PPS signal generator which utilizes STROBE pin of a parallel port to
    send PPS signals. It uses parport abstraction layer and hrtimers to
    precisely control the signal.

    [akpm@linux-foundation.org: fix build]
    Signed-off-by: Alexander Gordeev
    Acked-by: Rodolfo Giometti
    Cc: john stultz
    Signed-off-by: Andrew Morton
    Signed-off-by: Linus Torvalds

    Alexander Gordeev
     
  • Add an optional feature of PPSAPI, kernel consumer support, which uses the
    added hardpps() function.

    Signed-off-by: Alexander Gordeev
    Acked-by: Rodolfo Giometti
    Signed-off-by: Andrew Morton
    Signed-off-by: Linus Torvalds

    Alexander Gordeev
     

13 Mar, 2010

1 commit

  • Each PPS source can be registered/deregistered into the system by using
    special modules called "clients". They simply define the PPS sources'
    attributes and implement the time signal registration mechanism.

    This patch adds a special directory for such clients and adds a dummy
    client that can be useful to test system integrity on real systems.

    [akpm@linux-foundation.org: coding-style fixes]
    Signed-off-by: Rodolfo Giometti
    Cc: David Woodhouse
    Cc: Greg KH
    Cc: Alan Cox
    Cc: Alexander Gordeev
    Signed-off-by: Andrew Morton
    Signed-off-by: Linus Torvalds

    Rodolfo Giometti
     

19 Jun, 2009

1 commit

  • 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
    Cc: David Woodhouse
    Cc: Greg KH
    Cc: Randy Dunlap
    Cc: Kay Sievers
    Acked-by: Alan Cox
    Cc: Michael Kerrisk
    Cc: Christoph Hellwig
    Cc: Roman Zippel
    Signed-off-by: Andrew Morton
    Signed-off-by: Linus Torvalds

    Rodolfo Giometti