Eric Lee / smarc-fsl-linux-kernel

14 Jan, 2011

1 commit

  • 46b402a0e   pps: add parallel port PPS signal generator ... Browse Code »

    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
     

19 Jun, 2009

1 commit

  • eae9d2ba0   LinuxPPS: core support ... Browse Code »

    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