lkml.org 
[lkml]   [2010]   [Mar]   [1]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
Date
From
SubjectRe: [PATCHv2 3/6] pps: capture MONOTONIC_RAW timestamps as well
On Wed, Feb 24, 2010 at 03:28:14PM +0300, Alexander Gordeev wrote:
> MONOTONIC_RAW clock timestamps are ideally suited for frequency
> calculation and also fit well into the original NTP hardpps design. Now
> phase and frequency can be adjusted separately: the former based on
> REALTIME clock and the latter based on MONOTONIC_RAW clock.
> A new function getnstime_raw_and_real is added to timekeeping subsystem
> to capture both timestamps at the same time and atomically.
>
> Signed-off-by: Alexander Gordeev <lasaine@lvk.cs.msu.su>

Acked-by: Rodolfo Giometti <giometti@linux.it>

> ---
> include/linux/pps_kernel.h | 3 ++-
> include/linux/time.h | 2 ++
> kernel/time/timekeeping.c | 34 ++++++++++++++++++++++++++++++++++
> 3 files changed, 38 insertions(+), 1 deletions(-)
>
> diff --git a/include/linux/pps_kernel.h b/include/linux/pps_kernel.h
> index a2804c1..9bda892 100644
> --- a/include/linux/pps_kernel.h
> +++ b/include/linux/pps_kernel.h
> @@ -41,6 +41,7 @@ struct pps_source_info {
> };
>
> struct pps_event_time {
> + struct timespec ts_raw;
> struct pps_ktime ts_real;
> };
>
> @@ -104,7 +105,7 @@ static inline void pps_get_ts(struct pps_event_time *ts)
> {
> struct timespec ts_real;
>
> - getnstimeofday(&ts_real);
> + getnstime_raw_and_real(&ts->ts_raw, &ts_real);
> timespec_to_pps_ktime(&ts->ts_real, ts_real);
> }
>
> diff --git a/include/linux/time.h b/include/linux/time.h
> index 6e026e4..edf7eb7 100644
> --- a/include/linux/time.h
> +++ b/include/linux/time.h
> @@ -143,6 +143,8 @@ extern unsigned int alarm_setitimer(unsigned int seconds);
> extern int do_getitimer(int which, struct itimerval *value);
> extern void getnstimeofday(struct timespec *tv);
> extern void getrawmonotonic(struct timespec *ts);
> +extern void getnstime_raw_and_real(struct timespec *ts_raw,
> + struct timespec *ts_real);
> extern void getboottime(struct timespec *ts);
> extern void monotonic_to_bootbased(struct timespec *ts);
>
> diff --git a/kernel/time/timekeeping.c b/kernel/time/timekeeping.c
> index 8b709de..0ca8336 100644
> --- a/kernel/time/timekeeping.c
> +++ b/kernel/time/timekeeping.c
> @@ -293,6 +293,40 @@ void ktime_get_ts(struct timespec *ts)
> EXPORT_SYMBOL_GPL(ktime_get_ts);
>
> /**
> + * getnstime_raw_and_real - Returns both the time of day an raw
> + * monotonic time in a timespec format
> + * @ts_mono_raw: pointer to the timespec to be set to raw
> + * monotonic time
> + * @ts_real: pointer to the timespec to be set to the time
> + * of day
> + */
> +void getnstime_raw_and_real(struct timespec *ts_raw, struct timespec *ts_real)
> +{
> + unsigned long seq;
> + s64 nsecs_raw, nsecs_real;
> +
> + WARN_ON(timekeeping_suspended);
> +
> + do {
> + seq = read_seqbegin(&xtime_lock);
> +
> + *ts_raw = raw_time;
> + *ts_real = xtime;
> +
> + nsecs_raw = timekeeping_get_ns_raw();
> + nsecs_real = timekeeping_get_ns();
> +
> + /* If arch requires, add in gettimeoffset() */
> + nsecs_real += arch_gettimeoffset();
> +
> + } while (read_seqretry(&xtime_lock, seq));
> +
> + timespec_add_ns(ts_raw, nsecs_raw);
> + timespec_add_ns(ts_real, nsecs_real);
> +}
> +EXPORT_SYMBOL(getnstime_raw_and_real);
> +
> +/**
> * do_gettimeofday - Returns the time of day in a timeval
> * @tv: pointer to the timeval to be set
> *
> --
> 1.6.6.1
>

--

GNU/Linux Solutions e-mail: giometti@enneenne.com
Linux Device Driver giometti@linux.it
Embedded Systems phone: +39 349 2432127
UNIX programming skype: rodolfo.giometti
Freelance ICT Italia - Consulente ICT Italia - www.consulenti-ict.it


\
 
 \ /
  Last update: 2010-03-01 09:23    [from the cache]
©2003-2011 Jasper Spaans