ptp: add the PTP_SYS_OFFSET ioctl to the testptp program

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>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 63 insertions, 2 deletions

diff --git a/Documentation/ptp/testptp.c b/Documentation/ptp/testptp.c
index f59ded066108..a74d0a84d329 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;
 }