selftest/ptp: update ptp selftest to exercise the gettimex options

With the inclusion of commit c259acab839e ("ptp/ioctl: support
MONOTONIC{,_RAW} timestamps for PTP_SYS_OFFSET_EXTENDED") clock_gettime()
now allows retrieval of pre/post timestamps for CLOCK_MONOTONIC and
CLOCK_MONOTONIC_RAW timebases along with the previously supported
CLOCK_REALTIME.

This patch adds a command line option 'y' to the testptp program to
choose one of the allowed timebases [realtime aka system, monotonic,
and monotonic-raw).

Signed-off-by: Mahesh Bandewar <[e-mail]>
Cc: Shuah Khan <[e-mail]>
Acked-by: Richard Cochran <[e-mail]>
Link: https://patch.msgid.link/[e-mail]
Signed-off-by: Jakub Kicinski <[e-mail]>

tools/testing/selftests/ptp/testptp.c

···
 		" -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"
 		" -X         get a ptp clock cross timestamp\n"
+		" -y val     pre/post tstamp timebase to use {realtime|monotonic|monotonic-raw}\n"
 		" -z         test combinations of rising/falling external time stamp flags\n",
 		progname, PTP_MAX_SAMPLES);
 }
···
 	int seconds = 0;
 	int settime = 0;
 	int channel = -1;
+	clockid_t ext_clockid = CLOCK_REALTIME;
 
 	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, "cd:e:f:F:ghH:i:k:lL:n:o:p:P:sSt:T:w:x:Xz"))) {
+	while (EOF != (c = getopt(argc, argv, "cd:e:f:F:ghH:i:k:lL:n:o:p:P:sSt:T:w:x:Xy:z"))) {
 		switch (c) {
 		case 'c':
 			capabilities = 1;
···
 		case 'X':
 			getcross = 1;
 			break;
+		case 'y':
+			if (!strcasecmp(optarg, "realtime"))
+				ext_clockid = CLOCK_REALTIME;
+			else if (!strcasecmp(optarg, "monotonic"))
+				ext_clockid = CLOCK_MONOTONIC;
+			else if (!strcasecmp(optarg, "monotonic-raw"))
+				ext_clockid = CLOCK_MONOTONIC_RAW;
+			else {
+				fprintf(stderr,
+					"type needs to be realtime, monotonic or monotonic-raw; was given %s\n",
+					optarg);
+				return -1;
+			}
+			break;
+
 		case 'z':
 			flagtest = 1;
 			break;
···
 		}
 
 		soe->n_samples = getextended;
+		soe->clockid = ext_clockid;
 
 		if (ioctl(fd, PTP_SYS_OFFSET_EXTENDED, soe)) {
 			perror("PTP_SYS_OFFSET_EXTENDED");
···
 			       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);
+				switch (ext_clockid) {
+				case CLOCK_REALTIME:
+					printf("sample #%2d: real time before: %lld.%09u\n",
+					       i, soe->ts[i][0].sec,
+					       soe->ts[i][0].nsec);
+					break;
+				case CLOCK_MONOTONIC:
+					printf("sample #%2d: monotonic time before: %lld.%09u\n",
+					       i, soe->ts[i][0].sec,
+					       soe->ts[i][0].nsec);
+					break;
+				case CLOCK_MONOTONIC_RAW:
+					printf("sample #%2d: monotonic-raw time before: %lld.%09u\n",
+					       i, soe->ts[i][0].sec,
+					       soe->ts[i][0].nsec);
+					break;
+				default:
+					break;
+				}
 				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);
+				switch (ext_clockid) {
+				case CLOCK_REALTIME:
+					printf("            real time after: %lld.%09u\n",
+					       soe->ts[i][2].sec,
+					       soe->ts[i][2].nsec);
+					break;
+				case CLOCK_MONOTONIC:
+					printf("            monotonic time after: %lld.%09u\n",
+					       soe->ts[i][2].sec,
+					       soe->ts[i][2].nsec);
+					break;
+				case CLOCK_MONOTONIC_RAW:
+					printf("            monotonic-raw time after: %lld.%09u\n",
+					       soe->ts[i][2].sec,
+					       soe->ts[i][2].nsec);
+					break;
+				default:
+					break;
+				}
 			}
 		}