Commit 220a60a4 authored by Ben Hutchings's avatar Ben Hutchings
Browse files

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: default avatarBen Hutchings <bhutchings@solarflare.com>
parent ef2c7d7b

drivers/ptp/ptp_clock.c

+5 −0
Original line number Diff line number Diff line
@@ -300,6 +300,11 @@ void ptp_clock_event(struct ptp_clock *ptp, struct ptp_clock_event *event) 
		pps_get_ts(&evt);

		pps_event(ptp->pps_source, &evt, PTP_PPS_EVENT, NULL);

		break;



	case PTP_CLOCK_PPSUSR:

		pps_event(ptp->pps_source, &event->pps_times,

			  PTP_PPS_EVENT, NULL);

		break;

	}

}

EXPORT_SYMBOL(ptp_clock_event);

include/linux/pps_kernel.h

+9 −0
Original line number Diff line number Diff line
@@ -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 */

include/linux/ptp_clock_kernel.h

+8 −2
Original line number Diff line number Diff line
@@ -21,6 +21,7 @@ 
#ifndef _PTP_CLOCK_KERNEL_H_

#define _PTP_CLOCK_KERNEL_H_



#include <linux/pps_kernel.h>

#include <linux/ptp_clock.h>
@@ -110,6 +111,7 @@ enum ptp_clock_events { 
	PTP_CLOCK_ALARM,

	PTP_CLOCK_EXTTS,

	PTP_CLOCK_PPS,

	PTP_CLOCK_PPSUSR,

};



/**
@@ -117,13 +119,17 @@ enum ptp_clock_events { 
 *

 * @type:  One of the ptp_clock_events enumeration values.

 * @index: Identifies the source of the event.

 * @timestamp: When the event occured.

 * @timestamp: When the event occurred (%PTP_CLOCK_EXTTS only).

 * @pps_times: When the event occurred (%PTP_CLOCK_PPSUSR only).

 */



struct ptp_clock_event {

	int type;

	int index;

	union {

		u64 timestamp;

		struct pps_event_time pps_times;

	};

};



/**

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