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authorBen Hutchings <bhutchings@solarflare.com>2012-09-03 11:34:58 +0100
committerBen Hutchings <bhutchings@solarflare.com>2012-09-07 21:13:28 +0100
commit220a60a425146b0e37998cc0b3082f0541aad866 (patch)
tree44e48c4489f8e354d17269d41db19d015d9b95fe /include/linux/pps_kernel.h
parentef2c7d7b59708d54213c7556a82d14de9a7e4475 (diff)
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pps/ptp: Allow PHC devices to adjust PPS events for known delay
Initial version by Stuart Hodgson <smhodgson@solarflare.com> Some PHC device drivers may deliver PPS events with a significant and variable delay, but still be able to measure precisely what that delay is. Add a pps_sub_ts() function for subtracting a delay from the timestamp(s) in a PPS event, and a PTP event type (PTP_CLOCK_PPSUSR) for which the caller provides a complete PPS event. Signed-off-by: Ben Hutchings <bhutchings@solarflare.com>
Diffstat (limited to 'include/linux/pps_kernel.h')
-rw-r--r--include/linux/pps_kernel.h9
1 files changed, 9 insertions, 0 deletions
diff --git a/include/linux/pps_kernel.h b/include/linux/pps_kernel.h
index 94048547f29a..0cc45ae1afd5 100644
--- a/include/linux/pps_kernel.h
+++ b/include/linux/pps_kernel.h
@@ -116,5 +116,14 @@ static inline void pps_get_ts(struct pps_event_time *ts)
#endif /* CONFIG_NTP_PPS */
+/* Subtract known time delay from PPS event time(s) */
+static inline void pps_sub_ts(struct pps_event_time *ts, struct timespec delta)
+{
+ ts->ts_real = timespec_sub(ts->ts_real, delta);
+#ifdef CONFIG_NTP_PPS
+ ts->ts_raw = timespec_sub(ts->ts_raw, delta);
+#endif
+}
+
#endif /* LINUX_PPS_KERNEL_H */
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