Dear devel,
On Tuesday, 7 March 2023 15:26:48 CET, I wrote:
> I therefore suggest to change the edge-detection to use the pulse-width:
> Unless pulsewidth=NS_PER_SEC/2, from the time-interval relative to the
> previous event the edge can be determined uniquely, making involvement
> of the system time into acquiring a lock of the PHC unnecessary,
> completely avoid locking on the wrong edge and increase the capturing range.
Now, that the edge detection is independent of the system time, there is still
a problem with the 'generic' driver, as the TOD we lock to is still determined
by CLOCK_REALTIME.
The appended patch creates an alternative to "generic" named "extpps" that
strictly makes a phc follow the 1pps pulses, independent of the system time.
As a nice side-effect this eliminates completely the need for offsets,
leap-second tables, etc. within ts2phc and restricts it more precisely
to what it claims to do: "Synchronizes one or more PTP Hardware Clocks
using external time stamps."
After the user has set the PHC approximately to the intended time and offset:
phc_ctl /dev/ptp3 -- set adjust $(grep -v '^#'
/usr/share/zoneinfo/leap-seconds.list | tail -1 | awk '{ print $2 }')
ts2phc will keep the phc locked, no matter what happens to the system time.
This allows locking different PHCs to different time domains,
even if those clocks drift more than a second away.
Using separate 1PPs inputs I now can make different PHCs lock
simultaneously to '1PPs' pulses with periods 1010 ms and 1020 ms and when using
a stable 1PPs.
I noticed that the servo.c -code has a SERVO_LOCKED_STABLE state that is not
used.
Are there any plans with that? Lock-detection in combination with with sd_noify
(https://www.freedesktop.org/software/systemd/man/sd_notify.html) would sound
very useful to me.
Cheers, Jürgen
> =======================================
diff --git a/makefile b/makefile
index 3e3b8b3..5192a0f 100644
--- a/makefile
+++ b/makefile
@@ -26,8 +26,9 @@ PRG = ptp4l hwstamp_ctl nsm phc2sys phc_ctl pmc timemaster
ts2phc tz2alt
FILTERS = filter.o mave.o mmedian.o
SERVOS = linreg.o ntpshm.o nullf.o pi.o refclock_sock.o servo.o
TRANSP = raw.o transport.o udp.o udp6.o uds.o
-TS2PHC = ts2phc.o lstab.o nmea.o serial.o sock.o ts2phc_generic_pps_source.o \
- ts2phc_nmea_pps_source.o ts2phc_phc_pps_source.o ts2phc_pps_sink.o
ts2phc_pps_source.o
+TS2PHC = ts2phc.o lstab.o nmea.o serial.o sock.o ts2phc_extpps_pps_source.o \
+ ts2phc_generic_pps_source.o ts2phc_nmea_pps_source.o ts2phc_phc_pps_source.o \
+ ts2phc_pps_sink.o ts2phc_pps_source.o
OBJ = bmc.o clock.o clockadj.o clockcheck.o config.o designated_fsm.o \
e2e_tc.o fault.o $(FILTERS) fsm.o hash.o interface.o monitor.o msg.o phc.o \
port.o port_signaling.o pqueue.o print.o ptp4l.o p2p_tc.o rtnl.o $(SERVOS) \
diff --git a/ts2phc.c b/ts2phc.c
index 4393059..6a8cad9 100644
--- a/ts2phc.c
+++ b/ts2phc.c
@@ -467,7 +467,14 @@ static void ts2phc_synchronize_clocks(struct
ts2phc_private *priv, int autocfg)
continue;
}
- offset = tmv_to_nanoseconds(tmv_sub(ts, source_tmv));
+ if (source_tmv.ns)
+ offset = tmv_to_nanoseconds(tmv_sub(ts, source_tmv));
+ else {
+ /* no source timestamp => lock ts.ns to nearest whole second
*/
+ offset = tmv_to_nanoseconds(ts) % NS_PER_SEC;
+ if (offset > NS_PER_SEC/2)
+ offset -= NS_PER_SEC;
+ };
if (c->no_adj) {
pr_info("%s offset %10" PRId64, c->name,
@@ -547,7 +554,10 @@ static void usage(char *progname)
" -q do not print messages to the syslog\n"
" -s [dev|name] source of the PPS signal\n"
" may take any of the following forms:\n"
- " generic - an external 1-PPS without ToD
information\n"
+ " generic - an external 1-PPS without ToD
information,\n"
+ " ToD information taken from
CLOCK_REALTIME\n"
+ " extpps - an external 1-PPS without ToD
information,\n"
+ " lock PHCs towards nearest
whole second."
" /dev/ptp0 - a local PTP Hardware Clock
(PHC)\n"
" eth0 - a local PTP Hardware Clock
(PHC)\n"
" nmea - a gps device connected by
serial port or network\n"
@@ -731,6 +741,8 @@ int main(int argc, char *argv[])
if (!strcasecmp(tod_source, "generic")) {
pps_type = TS2PHC_PPS_SOURCE_GENERIC;
+ } else if (!strcasecmp(tod_source, "extpps")) {
+ pps_type = TS2PHC_PPS_SOURCE_EXTPPS;
} else if (!strcasecmp(tod_source, "nmea")) {
pps_type = TS2PHC_PPS_SOURCE_NMEA;
} else {
diff --git a/ts2phc_extpps_pps_source.c b/ts2phc_extpps_pps_source.c
new file mode 100644
index 0000000..4e1f26d
--- /dev/null
+++ b/ts2phc_extpps_pps_source.c
@@ -0,0 +1,51 @@
+/**
+ * @file ts2phc_extpps_pps_source.c
+ * @note Copyright (C) 2019 Richard Cochran <richardcoch...@gmail.com>
+ * @note SPDX-License-Identifier: GPL-2.0+
+ */
+#include <stdlib.h>
+#include <time.h>
+
+#include "ts2phc_extpps_pps_source.h"
+#include "ts2phc_pps_source_private.h"
+
+struct ts2phc_extpps_pps_source {
+ struct ts2phc_pps_source pps_source;
+};
+
+static void ts2phc_extpps_pps_source_destroy(struct ts2phc_pps_source *src)
+{
+ struct ts2phc_extpps_pps_source *s =
+ container_of(src, struct ts2phc_extpps_pps_source, pps_source);
+
+ free(s);
+}
+
+static int ts2phc_extpps_pps_source_getppstime(struct ts2phc_pps_source *src,
+ struct timespec *ts)
+{
+ ts->tv_sec = 0;
+ ts->tv_nsec = 0;
+ return 0;
+}
+
+struct ts2phc_clock *ts2phc_extpps_pps_source_get_clock(struct
ts2phc_pps_source *src)
+{
+ return NULL;
+}
+
+
+struct ts2phc_pps_source *ts2phc_extpps_pps_source_create(struct
ts2phc_private *priv,
+ const char *dev)
+{
+ struct ts2phc_extpps_pps_source *s;
+
+ s = calloc(1, sizeof(*s));
+ if (!s) {
+ return NULL;
+ }
+ s->pps_source.destroy = ts2phc_extpps_pps_source_destroy;
+ s->pps_source.getppstime = ts2phc_extpps_pps_source_getppstime;
+
+ return &s->pps_source;
+}
diff --git a/ts2phc_extpps_pps_source.h b/ts2phc_extpps_pps_source.h
new file mode 100644
index 0000000..1a57cd6
--- /dev/null
+++ b/ts2phc_extpps_pps_source.h
@@ -0,0 +1,15 @@
+/**
+ * @file ts2phc_extpps_pps_source.h
+ * @note Copyright (C) 2019 Richard Cochran <richardcoch...@gmail.com>
+ * @note SPDX-License-Identifier: GPL-2.0+
+ */
+#ifndef HAVE_TS2PHC_EXTPPS_PPS_SOURCE_H
+#define HAVE_TS2PHC_EXTPPS_PPS_SOURCE_H
+
+#include "ts2phc.h"
+#include "ts2phc_pps_source.h"
+
+struct ts2phc_pps_source *ts2phc_extpps_pps_source_create(struct
ts2phc_private *priv,
+ const char *dev);
+
+#endif
diff --git a/ts2phc_pps_source.c b/ts2phc_pps_source.c
index c333f65..be98567 100644
--- a/ts2phc_pps_source.c
+++ b/ts2phc_pps_source.c
@@ -5,6 +5,7 @@
*/
#include "ts2phc.h"
#include "ts2phc_generic_pps_source.h"
+#include "ts2phc_extpps_pps_source.h"
#include "ts2phc_nmea_pps_source.h"
#include "ts2phc_phc_pps_source.h"
#include "ts2phc_pps_source_private.h"
@@ -19,6 +20,9 @@ struct ts2phc_pps_source *ts2phc_pps_source_create(struct
ts2phc_private *priv,
case TS2PHC_PPS_SOURCE_GENERIC:
src = ts2phc_generic_pps_source_create(priv, dev);
break;
+ case TS2PHC_PPS_SOURCE_EXTPPS:
+ src = ts2phc_extpps_pps_source_create(priv, dev);
+ break;
case TS2PHC_PPS_SOURCE_NMEA:
src = ts2phc_nmea_pps_source_create(priv, dev);
break;
diff --git a/ts2phc_pps_source.h b/ts2phc_pps_source.h
index 293c693..519fc02 100644
--- a/ts2phc_pps_source.h
+++ b/ts2phc_pps_source.h
@@ -21,6 +21,7 @@ struct ts2phc_pps_source;
*/
enum ts2phc_pps_source_type {
TS2PHC_PPS_SOURCE_GENERIC,
+ TS2PHC_PPS_SOURCE_EXTPPS,
TS2PHC_PPS_SOURCE_NMEA,
TS2PHC_PPS_SOURCE_PHC,
};
> =======================================
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