[PATCH] ptp: measure the time offset between PHC and system clock

[Dong Zhu <bluezhudong@gmail.com>]

This patch add a method into testptp.c to measure the time offset
between phc and system clock through the ioctl PTP_SYS_OFFSET.

Signed-off-by: Dong Zhu <bluezhudong@gmail.com>
---
 Documentation/ptp/testptp.c | 40 ++++++++++++++++++++++++++++++++++++++--
 1 file changed, 38 insertions(+), 2 deletions(-)

diff --git a/Documentation/ptp/testptp.c b/Documentation/ptp/testptp.c
index f59ded0..72bb030 100644
--- a/Documentation/ptp/testptp.c
+++ b/Documentation/ptp/testptp.c
@@ -112,6 +112,7 @@ static void usage(char *progname)
 		" -f val     adjust the ptp clock frequency by 'val' ppb\n"
 		" -g         get the ptp clock time\n"
 		" -h         prints this message\n"
+		" -k val     measure the time offset between PHC and system clock\n"
 		" -p val     enable output with a period of 'val' nanoseconds\n"
 		" -P val     enable or disable (val=1|0) the system clock PPS\n"
 		" -s         set the ptp clock time from the system time\n"
@@ -133,8 +134,12 @@ int main(int argc, char *argv[])
 	struct itimerspec timeout;
 	struct sigevent sigevent;
 
+	struct ptp_clock_time *pct;
+	struct ptp_sys_offset *sysoff;
+
+
 	char *progname;
-	int c, cnt, fd;
+	int i, c, cnt, fd;
 
 	char *device = DEVICE;
 	clockid_t clkid;
@@ -144,6 +149,8 @@ int main(int argc, char *argv[])
 	int extts = 0;
 	int gettime = 0;
 	int oneshot = 0;
+	int offset = 0;
+	int n_samples = 0;
 	int periodic = 0;
 	int perout = -1;
 	int pps = -1;
@@ -151,7 +158,7 @@ int main(int argc, char *argv[])
 
 	progname = strrchr(argv[0], '/');
 	progname = progname ? 1+progname : argv[0];
-	while (EOF != (c = getopt(argc, argv, "a:A:cd:e:f:ghp:P:sSt:v"))) {
+	while (EOF != (c = getopt(argc, argv, "a:A:cd:e:f:ghk:p:P:sSt:v"))) {
 		switch (c) {
 		case 'a':
 			oneshot = atoi(optarg);
@@ -174,6 +181,10 @@ int main(int argc, char *argv[])
 		case 'g':
 			gettime = 1;
 			break;
+		case 'k':
+			offset = 1;
+			n_samples = atoi(optarg);
+			break;
 		case 'p':
 			perout = atoi(optarg);
 			break;
@@ -376,6 +387,31 @@ int main(int argc, char *argv[])
 		}
 	}
 
+	if (offset) {
+		sysoff = calloc(1, sizeof(*sysoff));
+		if (!sysoff) {
+			perror("calloc");
+			return -1;
+		}
+		sysoff->n_samples = n_samples;
+
+		if (ioctl(fd, PTP_SYS_OFFSET, sysoff))
+			perror("PTP_SYS_OFFSET");
+		else
+			puts("time offset between PHC and
+					 system clock request okay");
+
+		pct = &sysoff->ts[0];
+		for (i = 0; i < sysoff->n_samples; i++, pct++) {
+			printf("system time: %ld.%ld\n", pct->sec, pct->nsec);
+			pct++;
+			printf("phc    time: %ld.%ld\n\n", pct->sec, pct->nsec);
+		}
+		printf("system time: %ld.%ld\n", pct->sec, pct->nsec);
+
+		free(sysoff);
+	}
+
 	close(fd);
 	return 0;
 }
-- 
1.7.11.7


-- 
Best Regards,
Dong Zhu