testptp: add option to shift clock by nanoseconds

Add option to shift the clock by a specified number of nanoseconds.

The new argument -n will specify the number of nanoseconds to add to the
ptp clock. Since the API doesn't support negative shifts those needs to
be calculated by subtracting full seconds and adding a nanosecond offset.

Signed-off-by: Maciek Machnikowski <maciek@machnikowski.net>
Acked-by: Richard Cochran <richardcochran@gmail.com>
Link: https://lore.kernel.org/r/20220221200637.125595-1-maciek@machnikowski.net
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

diff --git a/tools/testing/selftests/ptp/testptp.c b/tools/testing/selftests/ptp/testptp.c
index c0f6a062364d03b61b982ed2d3d0131e8b0c7735..198ad5f321878fc44fe624e6c670afcdece8a584 100644 (file)
--- a/tools/testing/selftests/ptp/testptp.c
+++ b/tools/testing/selftests/ptp/testptp.c
@@ -133,6 +133,7 @@ static void usage(char *progname)
                "            0 - none\n"
                "            1 - external time stamp\n"
                "            2 - periodic output\n"
+               " -n val     shift the ptp clock time by 'val' nanoseconds\n"
                " -p val     enable output with a period of 'val' nanoseconds\n"
                " -H val     set output phase to 'val' nanoseconds (requires -p)\n"
                " -w val     set output pulse width to 'val' nanoseconds (requires -p)\n"
@@ -165,6 +166,7 @@ int main(int argc, char *argv[])
        clockid_t clkid;
        int adjfreq = 0x7fffffff;
        int adjtime = 0;
+       int adjns = 0;
        int capabilities = 0;
        int extts = 0;
        int flagtest = 0;
@@ -186,7 +188,7 @@ int main(int argc, char *argv[])
 
        progname = strrchr(argv[0], '/');
        progname = progname ? 1+progname : argv[0];
-       while (EOF != (c = getopt(argc, argv, "cd:e:f:ghH:i:k:lL:p:P:sSt:T:w:z"))) {
+       while (EOF != (c = getopt(argc, argv, "cd:e:f:ghH:i:k:lL:n:p:P:sSt:T:w:z"))) {
                switch (c) {
                case 'c':
                        capabilities = 1;
@@ -223,6 +225,9 @@ int main(int argc, char *argv[])
                                return -1;
                        }
                        break;
+               case 'n':
+                       adjns = atoi(optarg);
+                       break;
                case 'p':
                        perout = atoll(optarg);
                        break;
@@ -305,11 +310,16 @@ int main(int argc, char *argv[])
                }
        }
 
-       if (adjtime) {
+       if (adjtime || adjns) {
                memset(&tx, 0, sizeof(tx));
-               tx.modes = ADJ_SETOFFSET;
+               tx.modes = ADJ_SETOFFSET | ADJ_NANO;
                tx.time.tv_sec = adjtime;
-               tx.time.tv_usec = 0;
+               tx.time.tv_usec = adjns;
+               while (tx.time.tv_usec < 0) {
+                       tx.time.tv_sec  -= 1;
+                       tx.time.tv_usec += 1000000000;
+               }
+
                if (clock_adjtime(clkid, &tx) < 0) {
                        perror("clock_adjtime");
                } else {