Commit 796c1efd authored Dec 21, 2014 by Richard Cochran Committed by David S. Miller Dec 30, 2014

timecounter: provide a helper function to shift the time.



Some PTP Hardware Clock drivers use a struct timecounter to represent
their clock. To adjust the time by a given offset, these drivers all
perform a two step read/write of their timecounter. However, it is
better and simpler just to adjust the offset in one step. This patch
introduces a little routine to help drivers implement the adjtime
method.

Suggested-by: Janusz Użycki <j.uzycki@elproma.com.pl>
Signed-off-by: Richard Cochran <richardcochran@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

parent 74d23cc7

include/linux/timecounter.h

+9 −0

Original line number	Diff line number	Diff line
		@@ -78,6 +78,15 @@ static inline u64 cyclecounter_cyc2ns(const struct cyclecounter *cc,
		return ret;
		}

		/**
		* timecounter_adjtime - Shifts the time of the clock.
		* @delta: Desired change in nanoseconds.
		*/
		static inline void timecounter_adjtime(struct timecounter *tc, s64 delta)
		{
		tc->nsec += delta;
		}

		/**
		* timecounter_init - initialize a time counter
		* @tc: Pointer to time counter which is to be initialized/reset