Subject: [PATCH net-next 2/2] testptp: add new options for perout phase and pulse width

From: Vladimir Oltean <[email-masked]>
Date: Mon, 20 Jul 2020 20:55:59 +0300

Extend the example program for PTP ancillary functionality with the
ability to configure not only the periodic output's period (frequency),
but also the phase and duty cycle (pulse width) which were newly
introduced.

The ioctl level also needs to be updated to the new PTP_PEROUT_REQUEST2,
since the original PTP_PEROUT_REQUEST doesn't support this
functionality. For an in-tree testing program, not having explicit
backwards compatibility is fine, as it should always be tested with the
current kernel headers and sources.

Tested with an oscilloscope on the felix switch PHC:

echo '2 0' > /sys/class/ptp/ptp1/pins/switch_1588_dat0
./testptp -d /dev/ptp1 -p 1000000000 -w 100000000 -H 1000 -i 0

Signed-off-by: Vladimir Oltean <[email-masked]>
---
 tools/testing/selftests/ptp/testptp.c | 41 ++++++++++++++++++++++++---
 1 file changed, 37 insertions(+), 4 deletions(-)

diff --git a/tools/testing/selftests/ptp/testptp.c b/tools/testing/selftests/ptp/testptp.c
index edc1e50768c2..f7911aaeb007 100644
--- a/tools/testing/selftests/ptp/testptp.c
+++ b/tools/testing/selftests/ptp/testptp.c
@@ -134,6 +134,8 @@ static void usage(char *progname)
 		"            1 - external time stamp\n"
 		"            2 - periodic output\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"
 		" -P val     enable or disable (val=1|0) the system clock PPS\n"
 		" -s         set the ptp clock time from the system time\n"
 		" -S         set the system time from the ptp clock time\n"
@@ -178,11 +180,13 @@ int main(int argc, char *argv[])
 
 	int64_t t1, t2, tp;
 	int64_t interval, offset;
+	int64_t perout_phase = -1;
+	int64_t pulsewidth = -1;
 	int64_t perout = -1;
 
 	progname = strrchr(argv[0], '/');
 	progname = progname ? 1+progname : argv[0];
-	while (EOF != (c = getopt(argc, argv, "cd:e:f:ghi:k:lL:p:P:sSt:T:z"))) {
+	while (EOF != (c = getopt(argc, argv, "cd:e:f:ghH:i:k:lL:p:P:sSt:T:w:z"))) {
 		switch (c) {
 		case 'c':
 			capabilities = 1;
@@ -199,6 +203,9 @@ int main(int argc, char *argv[])
 		case 'g':
 			gettime = 1;
 			break;
+		case 'H':
+			perout_phase = atoll(optarg);
+			break;
 		case 'i':
 			index = atoi(optarg);
 			break;
@@ -235,6 +242,9 @@ int main(int argc, char *argv[])
 			settime = 3;
 			seconds = atoi(optarg);
 			break;
+		case 'w':
+			pulsewidth = atoi(optarg);
+			break;
 		case 'z':
 			flagtest = 1;
 			break;
@@ -393,6 +403,16 @@ int main(int argc, char *argv[])
 		}
 	}
 
+	if (pulsewidth >= 0 && perout < 0) {
+		puts("-w can only be specified together with -p");
+		return -1;
+	}
+
+	if (perout_phase >= 0 && perout < 0) {
+		puts("-H can only be specified together with -p");
+		return -1;
+	}
+
 	if (perout >= 0) {
 		if (clock_gettime(clkid, &ts)) {
 			perror("clock_gettime");
@@ -400,11 +420,24 @@ int main(int argc, char *argv[])
 		}
 		memset(&perout_request, 0, sizeof(perout_request));
 		perout_request.index = index;
-		perout_request.start.sec = ts.tv_sec + 2;
-		perout_request.start.nsec = 0;
 		perout_request.period.sec = perout / NSEC_PER_SEC;
 		perout_request.period.nsec = perout % NSEC_PER_SEC;
-		if (ioctl(fd, PTP_PEROUT_REQUEST, &perout_request)) {
+		perout_request.flags = 0;
+		if (pulsewidth >= 0) {
+			perout_request.flags |= PTP_PEROUT_DUTY_CYCLE;
+			perout_request.on.sec = pulsewidth / NSEC_PER_SEC;
+			perout_request.on.nsec = pulsewidth % NSEC_PER_SEC;
+		}
+		if (perout_phase >= 0) {
+			perout_request.flags |= PTP_PEROUT_PHASE;
+			perout_request.phase.sec = perout_phase / NSEC_PER_SEC;
+			perout_request.phase.nsec = perout_phase % NSEC_PER_SEC;
+		} else {
+			perout_request.start.sec = ts.tv_sec + 2;
+			perout_request.start.nsec = 0;
+		}
+
+		if (ioctl(fd, PTP_PEROUT_REQUEST2, &perout_request)) {
 			perror("PTP_PEROUT_REQUEST");
 		} else {
 			puts("periodic output request okay");
-- 
2.25.1