ts2phc: Support using a PHC as the master clock.

This patch introduces a new ts2phc source using a PHC device.  There
are multiple use cases for such a master.  By connecting pins of two
or more separate PHC devices together, one may act as the source, and
the others may be synchronized to it in hardware.  In this way, "just
a bunch of devices" together forms a Transparent Clock.  If the master
clock is synchronized to a global time source (like a PPS from a GPS),
then the system becomes a mutli-port Grand Master or a Boundary Clock
with GM capability.

Signed-off-by: Richard Cochran <richardcochran@gmail.com>

configs/ts2phc-TC.cfg

@@ -0,0 +1,27 @@
+#
+# This example shows ts2phc keeping a group of three Intel i210 cards
+# synchronized to each other in order to form a Transparent Clock.
+# The cards are configured to use their SDP0 pins connected in
+# hardware.  Here eth3 and eth4 will be slaved to eth6.
+#
+# Important!  The polarity is set to "both" because the i210 always
+# time stamps both the rising and the falling edges of the input
+# signal.
+#
+[global]
+use_syslog		0
+verbose			1
+logging_level		6
+ts2phc.pulsewidth	500000000
+[eth6]
+ts2phc.channel		0
+ts2phc.master		1
+ts2phc.pin_index	0
+[eth3]
+ts2phc.channel		0
+ts2phc.extts_polarity	both
+ts2phc.pin_index	0
+[eth4]
+ts2phc.channel		0
+ts2phc.extts_polarity	both
+ts2phc.pin_index	0

makefile

@@ -26,7 +26,8 @@ PRG	= ptp4l hwstamp_ctl nsm phc2sys phc_ctl pmc timemaster ts2phc
 FILTERS	= filter.o mave.o mmedian.o
 SERVOS	= linreg.o ntpshm.o nullf.o pi.o servo.o
 TRANSP	= raw.o transport.o udp.o udp6.o uds.o
-TS2PHC	= ts2phc.o ts2phc_generic_master.o ts2phc_master.o ts2phc_slave.o
+TS2PHC	= ts2phc.o ts2phc_generic_master.o ts2phc_master.o ts2phc_phc_master.o \
+ ts2phc_slave.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 msg.o phc.o port.o \
  port_signaling.o pqueue.o print.o ptp4l.o p2p_tc.o rtnl.o $(SERVOS) sk.o \

ts2phc.c

@@ -45,6 +45,8 @@ static void usage(char *progname)
 		" -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"
+		"                    /dev/ptp0 - a local PTP Hardware Clock (PHC)\n"
+		"                    eth0      - a local PTP Hardware Clock (PHC)\n"
 		" -v             prints the software version and exits\n"
 		"\n",
 		progname);
@@ -179,7 +181,11 @@ int main(int argc, char *argv[])
 		return -1;
 	}
 
+	if (!strcasecmp(pps_source, "generic")) {
 		pps_type = TS2PHC_MASTER_GENERIC;
+	} else {
+		pps_type = TS2PHC_MASTER_PHC;
+	}
 	master = ts2phc_master_create(cfg, pps_source, pps_type);
 	if (!master) {
 		fprintf(stderr, "failed to create master\n");

ts2phc_master.c

@@ -5,6 +5,7 @@
  */
 #include "ts2phc_generic_master.h"
 #include "ts2phc_master_private.h"
+#include "ts2phc_phc_master.h"
 
 struct ts2phc_master *ts2phc_master_create(struct config *cfg, const char *dev,
 					   enum ts2phc_master_type type)
@@ -18,6 +19,7 @@ struct ts2phc_master *ts2phc_master_create(struct config *cfg, const char *dev,
 	case TS2PHC_MASTER_NMEA:
 		break;
 	case TS2PHC_MASTER_PHC:
+		master = ts2phc_phc_master_create(cfg, dev);
 		break;
 	}
 	return master;

ts2phc_phc_master.c

@@ -0,0 +1,113 @@
+/**
+ * @file ts2phc_phc_master.c
+ * @note Copyright (C) 2019 Richard Cochran <richardcochran@gmail.com>
+ * @note SPDX-License-Identifier: GPL-2.0+
+ */
+#include <linux/ptp_clock.h>
+#include <stdlib.h>
+#include <string.h>
+#include <sys/ioctl.h>
+
+#include "config.h"
+#include "phc.h"
+#include "print.h"
+#include "missing.h"
+#include "ts2phc_master_private.h"
+#include "ts2phc_phc_master.h"
+#include "util.h"
+
+struct ts2phc_phc_master {
+	struct ts2phc_master master;
+	clockid_t clkid;
+	int channel;
+	int fd;
+};
+
+static int ts2phc_phc_master_activate(struct config *cfg, const char *dev,
+				      struct ts2phc_phc_master *master)
+{
+	struct ptp_perout_request perout_request;
+	struct ptp_pin_desc desc;
+	struct timespec ts;
+
+	memset(&desc, 0, sizeof(desc));
+
+	master->channel = config_get_int(cfg, dev, "ts2phc.channel");
+
+	desc.index = config_get_int(cfg, dev, "ts2phc.pin_index");
+	desc.func = PTP_PF_PEROUT;
+	desc.chan = master->channel;
+
+	if (phc_pin_setfunc(master->clkid, &desc)) {
+		pr_warning("Failed to set the pin. Continuing bravely on...");
+	}
+	if (clock_gettime(master->clkid, &ts)) {
+		perror("clock_gettime");
+		return -1;
+	}
+	memset(&perout_request, 0, sizeof(perout_request));
+	perout_request.index = master->channel;
+	perout_request.start.sec = ts.tv_sec + 2;
+	perout_request.start.nsec = 0;
+	perout_request.period.sec = 1;
+	perout_request.period.nsec = 0;
+
+	if (ioctl(master->fd, PTP_PEROUT_REQUEST2, &perout_request)) {
+		pr_err(PTP_PEROUT_REQUEST_FAILED);
+		return -1;
+	}
+	return 0;
+}
+
+static void ts2phc_phc_master_destroy(struct ts2phc_master *master)
+{
+	struct ts2phc_phc_master *m =
+		container_of(master, struct ts2phc_phc_master, master);
+	struct ptp_perout_request perout_request;
+
+	memset(&perout_request, 0, sizeof(perout_request));
+	perout_request.index = m->channel;
+	if (ioctl(m->fd, PTP_PEROUT_REQUEST2, &perout_request)) {
+		pr_err(PTP_PEROUT_REQUEST_FAILED);
+	}
+	posix_clock_close(m->clkid);
+	free(m);
+}
+
+static int ts2phc_phc_master_getppstime(struct ts2phc_master *m,
+					struct timespec *ts)
+{
+	struct ts2phc_phc_master *master =
+		container_of(m, struct ts2phc_phc_master, master);
+	return clock_gettime(master->clkid, ts);
+}
+
+struct ts2phc_master *ts2phc_phc_master_create(struct config *cfg,
+					       const char *dev)
+{
+	struct ts2phc_phc_master *master;
+	int junk;
+
+	master = calloc(1, sizeof(*master));
+	if (!master) {
+		return NULL;
+	}
+	master->master.destroy = ts2phc_phc_master_destroy;
+	master->master.getppstime = ts2phc_phc_master_getppstime;
+
+	master->clkid = posix_clock_open(dev, &junk);
+	if (master->clkid == CLOCK_INVALID) {
+		free(master);
+		return NULL;
+	}
+	master->fd = CLOCKID_TO_FD(master->clkid);
+
+	pr_debug("PHC master %s has ptp index %d", dev, junk);
+
+	if (ts2phc_phc_master_activate(cfg, dev, master)) {
+		ts2phc_phc_master_destroy(&master->master);
+		return NULL;
+	}
+
+	return &master->master;
+}

ts2phc_phc_master.h

@@ -0,0 +1,14 @@
+/**
+ * @file ts2phc_phc_master.h
+ * @note Copyright (C) 2019 Richard Cochran <richardcochran@gmail.com>
+ * @note SPDX-License-Identifier: GPL-2.0+
+ */
+#ifndef HAVE_TS2PHC_PHC_MASTER_H
+#define HAVE_TS2PHC_PHC_MASTER_H
+
+#include "ts2phc_master.h"
+
+struct ts2phc_master *ts2phc_phc_master_create(struct config *cfg,
+					       const char *dev);
+
+#endif