Hi Richard,
I developed a new patch and added a method to estimate the time offset
between system and phc clock.
Could you help reviewing it again ? If it do make sense I hope it could
be accepted.
Thanks !
>From e524e3b68f3df3cd91acd814490d092bad05386b Mon Sep 17 00:00:00 2001
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@xxxxxxxxx>
---
Documentation/ptp/testptp.c | 65 +++++++++++++++++++++++++++++++++++++++++++--
1 file changed, 63 insertions(+), 2 deletions(-)
diff --git a/Documentation/ptp/testptp.c b/Documentation/ptp/testptp.c
index f59ded0..a74d0a8 100644
--- a/Documentation/ptp/testptp.c
+++ b/Documentation/ptp/testptp.c
@@ -100,6 +100,11 @@ static long ppb_to_scaled_ppm(int ppb)
return (long) (ppb * 65.536);
}
+static int64_t pctns(struct ptp_clock_time *t)
+{
+ return t->sec * 1000000000LL + t->nsec;
+}
+
static void usage(char *progname)
{
fprintf(stderr,
@@ -112,6 +117,8 @@ 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 system and phc clock\n"
+ " for 'val' times (Maximum 25)\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 +140,12 @@ 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;
@@ -144,14 +155,19 @@ int main(int argc, char *argv[])
int extts = 0;
int gettime = 0;
int oneshot = 0;
+ int pct_offset = 0;
+ int n_samples = 0;
int periodic = 0;
int perout = -1;
int pps = -1;
int settime = 0;
+ int64_t t1, t2, tp;
+ int64_t interval, offset;
+
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 +190,10 @@ int main(int argc, char *argv[])
case 'g':
gettime = 1;
break;
+ case 'k':
+ pct_offset = 1;
+ n_samples = atoi(optarg);
+ break;
case 'p':
perout = atoi(optarg);
break;
@@ -376,6 +396,47 @@ int main(int argc, char *argv[])
}
}
+ if (pct_offset) {
+ if (n_samples <= 0 || n_samples > 25) {
+ puts("n_samples should be between 1 and 25");
+ usage(progname);
+ return -1;
+ }
+
+ 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("system and phc clock time offset request okay");
+
+ pct = &sysoff->ts[0];
+ for (i = 0; i < sysoff->n_samples; i++) {
+ t1 = pctns(pct+2*i);
+ tp = pctns(pct+2*i+1);
+ t2 = pctns(pct+2*i+2);
+ interval = t2 - t1;
+ offset = (t2 + t1) / 2 - tp;
+
+ printf("system time: %ld.%ld\n",
+ (pct+2*i)->sec, (pct+2*i)->nsec);
+ printf("phc time: %ld.%ld\n",
+ (pct+2*i+1)->sec, (pct+2*i+1)->nsec);
+ printf("system time: %ld.%ld\n",
+ (pct+2*i+2)->sec, (pct+2*i+2)->nsec);
+ printf("system/phc clock time offset is %ld ns\n"
+ "system clock time delay is %ld ns\n",
+ offset, interval);
+ }
+
+ free(sysoff);
+ }
+
close(fd);
return 0;
}
--
1.7.11.7
--
Best Regards,
Dong Zhu
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