Implement auto mode for frequency setting. In this mode the tool
will measure the frequency difference between PHC and CLOCK_REALTIME
and apply the correction to the PHC to match the system clock.
Signed-off-by: Maciek Machnikowski <mac...@machnikowski.net>
---
phc_ctl.8 | 13 +++++++-
phc_ctl.c | 92 +++++++++++++++++++++++++++++++++++++++++++------------
2 files changed, 84 insertions(+), 21 deletions(-)
diff --git a/phc_ctl.8 b/phc_ctl.8
index 650e661..c9e37e2 100644
--- a/phc_ctl.8
+++ b/phc_ctl.8
@@ -60,7 +60,8 @@ Adjust the PHC clock by an amount of seconds provided. This
argument is required
.BI freq " ppb"
Adjust the frequency of the PHC clock by the specified parts per billion. If no
argument is provided, it will attempt to read the current frequency and report
-it.
+it. If keyword "auto" is passed, the frequency of the PHC clock will be
adjusted
+to match the frequency of the CLOCK_REALTIME.
.TP
.BI cmp
Compare the PHC clock device to CLOCK_REALTIME, using the best method
available.
@@ -95,6 +96,16 @@ Set PHC clock time to 0 (seconds since Epoch)
\f(CWphc_ctl /dev/ptp0 set 0.0\fP
.RE
+Set PHC frequency to a negative value
+.RS
+\f(CWphc_ctl /dev/ptp0 -- freq -10\fP
+.RE
+
+Set PHC frequency and time from the system clock
+.RS
+\f(CWphc_ctl /dev/ptp0 -- freq auto set\fP
+.RE
+
Quickly sanity check frequency slewing by setting slewing frequency by positive
10%, resetting clock to 0.0 time, waiting for 10 seconds, and then reading
time. The time read back should be (roughly) 11 seconds, since the clock was
diff --git a/phc_ctl.c b/phc_ctl.c
index 6a5c2f4..6a66b1a 100644
--- a/phc_ctl.c
+++ b/phc_ctl.c
@@ -49,6 +49,7 @@
#include "version.h"
#define NSEC2SEC 1000000000.0
+#define N_SAMPLES 9
/* trap the alarm signal so that pause() will wake up on receipt */
static void handle_alarm(int s)
@@ -243,35 +244,88 @@ static int do_adj(clockid_t clkid, int cmdc, char *cmdv[])
static int do_freq(clockid_t clkid, int cmdc, char *cmdv[])
{
- double ppb;
+ int64_t t1_sys_offset, t1_delay, t2_sys_offset, t2_delay;
+ struct timespec t1_clk, t1_sys, t2_clk, t2_sys;
+ uint64_t t1_sys_ts, t2_sys_ts;
+ int64_t clk_diff, sys_diff;
enum parser_result r;
+ int method, fd;
+ double ppb;
clockadj_init(clkid);
-
if (cmdc < 1 || name_is_a_command(cmdv[0])) {
ppb = clockadj_get_freq(clkid);
pr_err("clock frequency offset is %lfppb", ppb);
/* no argument was used */
return 0;
- }
+ } else if (strcmp(cmdv[0], "auto") == 0) {
+ /* set the PHC freq to match the system time */
+ fd = CLOCKID_TO_FD(clkid);
- /* parse the double ppb argument */
- r = get_ranged_double(cmdv[0], &ppb, -NSEC2SEC, NSEC2SEC);
- switch (r) {
- case PARSED_OK:
- break;
- case MALFORMED:
- pr_err("freq: '%s' is not a valid double", cmdv[0]);
- return -2;
- case OUT_OF_RANGE:
- pr_err("freq: '%s' is out of range.", cmdv[0]);
- return -2;
- default:
- pr_err("freq: couldn't process '%s'", cmdv[0]);
- return -2;
- }
+ ppb = clockadj_get_freq(clkid);
+
+ /* Try sysoff first */
+ method = sysoff_probe(fd, N_SAMPLES);
+ if (method >= 0) {
+ if (sysoff_measure(fd, method, N_SAMPLES,
+ &t1_sys_offset,
+ &t1_sys_ts, &t1_delay)) {
+ return -1;
+ }
+
+ sleep(1);
+ if (sysoff_measure(fd, method, N_SAMPLES,
+ &t2_sys_offset,
+ &t2_sys_ts, &t2_delay)) {
+ return -1;
+ }
+
+ sys_diff = t2_sys_ts - t1_sys_ts;
+ clk_diff = t2_sys_offset - t1_sys_offset;
+ ppb += (1e9 - ppb) * ((double)clk_diff /
(double)sys_diff);
+ } else {
+ /* if sysoff is not available - try gettime */
+ if (clock_gettime(clkid, &t1_clk)) {
+ pr_err("get: failed to get clock time: %s",
+ strerror(errno));
+ return -1;
+ }
+ clock_gettime(CLOCK_REALTIME, &t1_sys);
+
+ sleep(1);
+
+ if (clock_gettime(clkid, &t2_clk)) {
+ pr_err("get: failed to get clock time: %s",
+ strerror(errno));
+ return -1;
+ }
+ clock_gettime(CLOCK_REALTIME, &t2_sys);
+
+ clk_diff = NSEC2SEC * (t2_clk.tv_sec - t1_clk.tv_sec) +
+ (t2_clk.tv_nsec - t1_clk.tv_nsec);
+ sys_diff = NSEC2SEC * (t2_sys.tv_sec - t1_sys.tv_sec) +
+ (t2_sys.tv_nsec - t1_sys.tv_nsec);
+ ppb += (1e9 - ppb) * (1 - (double)clk_diff /
(double)sys_diff);
+ }
+ } else {
+ /* parse the double ppb argument */
+ r = get_ranged_double(cmdv[0], &ppb, -NSEC2SEC, NSEC2SEC);
+ switch (r) {
+ case PARSED_OK:
+ break;
+ case MALFORMED:
+ pr_err("freq: '%s' is not a valid double", cmdv[0]);
+ return -2;
+ case OUT_OF_RANGE:
+ pr_err("freq: '%s' is out of range.", cmdv[0]);
+ return -2;
+ default:
+ pr_err("freq: couldn't process '%s'", cmdv[0]);
+ return -2;
+ }
+ }
clockadj_set_freq(clkid, ppb);
pr_err("adjusted clock frequency offset to %lfppb", ppb);
@@ -326,8 +380,6 @@ static int do_cmp(clockid_t clkid, int cmdc, char *cmdv[])
uint64_t sys_ts;
int method, fd;
-#define N_SAMPLES 9
-
fd = CLOCKID_TO_FD(clkid);
method = sysoff_probe(fd, N_SAMPLES);
--
2.34.1
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