pps: capture MONOTONIC_RAW timestamps as well

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: John Stultz <johnstul@us.ibm.com>
Cc: Rodolfo Giometti <giometti@enneenne.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

2 files changed, 16 insertions, 0 deletions

diff --git a/include/linux/pps_kernel.h b/include/linux/pps_kernel.h
index 1aedf50088cf..94048547f29a 100644
--- a/include/linux/pps_kernel.h
+++ b/include/linux/pps_kernel.h
@@ -47,6 +47,9 @@ struct pps_source_info {
 };
 
 struct pps_event_time {
+#ifdef CONFIG_NTP_PPS
+        struct timespec ts_raw;
+#endif /* CONFIG_NTP_PPS */
         struct timespec ts_real;
 };
 
@@ -97,10 +100,21 @@ static inline void timespec_to_pps_ktime(struct pps_ktime *kt,
         kt->nsec = ts.tv_nsec;
 }
 
+#ifdef CONFIG_NTP_PPS
+
+static inline void pps_get_ts(struct pps_event_time *ts)
+{
+        getnstime_raw_and_real(&ts->ts_raw, &ts->ts_real);
+}
+
+#else /* CONFIG_NTP_PPS */
+
 static inline void pps_get_ts(struct pps_event_time *ts)
 {
         getnstimeofday(&ts->ts_real);
 }
 
+#endif /* CONFIG_NTP_PPS */
+
 #endif /* LINUX_PPS_KERNEL_H */
 
diff --git a/include/linux/time.h b/include/linux/time.h
index 9f15ac7ab92a..1e6d3b59238d 100644
--- a/include/linux/time.h
+++ b/include/linux/time.h
@@ -158,6 +158,8 @@ 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);