selftests/ptp: Add -x option for testing PTP_SYS_OFFSET_EXTENDED

The -x option (where 'x' stands for eXtended) takes an argument which
represents the number of samples to request from the PTP device.
The help message will display the maximum number of samples allowed.
Providing an invalid argument will also display the maximum number of
samples allowed.

Signed-off-by: Alex Maftei <[e-mail]>
Signed-off-by: David S. Miller <[e-mail]>

tools/testing/selftests/ptp/testptp.c

···
 		" -S         set the system time from the ptp clock time\n"
 		" -t val     shift the ptp clock time by 'val' seconds\n"
 		" -T val     set the ptp clock time to 'val' seconds\n"
+		" -x val     get an extended ptp clock time with the desired number of samples (up to %d)\n"
 		" -z         test combinations of rising/falling external time stamp flags\n",
-		progname);
+		progname, PTP_MAX_SAMPLES);
 }
 
 int main(int argc, char *argv[])
···
 	struct timex tx;
 	struct ptp_clock_time *pct;
 	struct ptp_sys_offset *sysoff;
+	struct ptp_sys_offset_extended *soe;
 
 	char *progname;
 	unsigned int i;
···
 	int index = 0;
 	int list_pins = 0;
 	int pct_offset = 0;
+	int getextended = 0;
 	int n_samples = 0;
 	int pin_index = -1, pin_func;
 	int pps = -1;
···
 
 	progname = strrchr(argv[0], '/');
 	progname = progname ? 1+progname : argv[0];
-	while (EOF != (c = getopt(argc, argv, "cd:e:f:ghH:i:k:lL:n:o:p:P:sSt:T:w:z"))) {
+	while (EOF != (c = getopt(argc, argv, "cd:e:f:ghH:i:k:lL:n:o:p:P:sSt:T:w:x:z"))) {
 		switch (c) {
 		case 'c':
 			capabilities = 1;
···
 			break;
 		case 'w':
 			pulsewidth = atoi(optarg);
+			break;
+		case 'x':
+			getextended = atoi(optarg);
+			if (getextended < 1 || getextended > PTP_MAX_SAMPLES) {
+				fprintf(stderr,
+					"number of extended timestamp samples must be between 1 and %d; was asked for %d\n",
+					PTP_MAX_SAMPLES, getextended);
+				return -1;
+			}
 			break;
 		case 'z':
 			flagtest = 1;
···
 		}
 
 		free(sysoff);
+	}
+
+	if (getextended) {
+		soe = calloc(1, sizeof(*soe));
+		if (!soe) {
+			perror("calloc");
+			return -1;
+		}
+
+		soe->n_samples = getextended;
+
+		if (ioctl(fd, PTP_SYS_OFFSET_EXTENDED, soe)) {
+			perror("PTP_SYS_OFFSET_EXTENDED");
+		} else {
+			printf("extended timestamp request returned %d samples\n",
+			       getextended);
+
+			for (i = 0; i < getextended; i++) {
+				printf("sample #%2d: system time before: %lld.%09u\n",
+				       i, soe->ts[i][0].sec, soe->ts[i][0].nsec);
+				printf("            phc time: %lld.%09u\n",
+				       soe->ts[i][1].sec, soe->ts[i][1].nsec);
+				printf("            system time after: %lld.%09u\n",
+				       soe->ts[i][2].sec, soe->ts[i][2].nsec);
+			}
+		}
+
+		free(soe);
 	}
 
 	close(fd);