From 09fdc45220110d29e6952b3ba0190c6889db8557 Mon Sep 17 00:00:00 2001
From: Miroslav Lichvar <mlichvar@redhat.com>
Date: Tue, 5 Feb 2013 17:36:04 +0100
Subject: [PATCH] phc2sys: Add option to set step threshold.

Signed-off-by: Miroslav Lichvar <mlichvar@redhat.com>
---
 phc2sys.8 | 6 ++++++
 phc2sys.c | 6 +++++-
 2 files changed, 11 insertions(+), 1 deletion(-)

diff --git a/phc2sys.8 b/phc2sys.8
index e26641a..58d0b49 100644
--- a/phc2sys.8
+++ b/phc2sys.8
@@ -81,6 +81,12 @@ Specify the proportional constant of the PI controller. The default is 0.7.
 .BI \-I " ki"
 Specify the integral constant of the PI controller. The default is 0.3.
 .TP
+.BI \-S " step"
+Specify the step threshold of the PI controller. It is the maximum offset that
+the controller corrects by changing the clock frequency instead of stepping the
+clock. The clock is always stepped on start. The value of 0.0 disables stepping
+after the start. The default is 0.0.
+.TP
 .BI \-R " update-rate"
 Specify the slave clock update rate when running in the direct synchronization
 mode. The default is 1 per second.
diff --git a/phc2sys.c b/phc2sys.c
index 8e6b79f..5b8a28b 100644
--- a/phc2sys.c
+++ b/phc2sys.c
@@ -420,6 +420,7 @@ static void usage(char *progname)
 		" -i [iface]     master clock by network interface\n"
 		" -P [kp]        proportional constant (0.7)\n"
 		" -I [ki]        integration constant (0.3)\n"
+		" -S [step]      step threshold (disabled)\n"
 		" -R [rate]      slave clock update rate in HZ (1)\n"
 		" -N [num]       number of master clock readings per update (5)\n"
 		" -O [offset]    slave-master time offset (0)\n"
@@ -448,7 +449,7 @@ int main(int argc, char *argv[])
 	/* Process the command line arguments. */
 	progname = strrchr(argv[0], '/');
 	progname = progname ? 1+progname : argv[0];
-	while (EOF != (c = getopt(argc, argv, "c:d:hs:P:I:R:N:O:i:wv"))) {
+	while (EOF != (c = getopt(argc, argv, "c:d:hs:P:I:S:R:N:O:i:wv"))) {
 		switch (c) {
 		case 'c':
 			dst_clock.clkid = clock_open(optarg);
@@ -465,6 +466,9 @@ int main(int argc, char *argv[])
 		case 'I':
 			configured_pi_ki = atof(optarg);
 			break;
+		case 'S':
+			configured_pi_offset = atof(optarg);
+			break;
 		case 'R':
 			phc_rate = atoi(optarg);
 			break;