support changing UTC/TAI offset

This patch adds support for modifying the utc/tai offset. The "set" time operation, when called with a NULL pointer to the time structure, will do the operation in its own arch-specific way. Signed-off-by: Alessandro Rubini <rubini@gnudd.com>

support changing UTC/TAI offset
This patch adds support for modifying the utc/tai offset. The "set" time operation, when called with a NULL pointer to the time structure, will do the operation in its own arch-specific way. Signed-off-by: Alessandro Rubini <rubini@gnudd.com>
fe4470bb · Alessandro Rubini · c842f754 · fe4470bb · fe4470bb · fe4470bb
Commit fe4470bb authored Sep 30, 2013 by Alessandro Rubini
6 changed files
--- a/include/ppsi/ppsi.h
+++ b/include/ppsi/ppsi.h
@@ -155,7 +155,7 @@ extern struct pp_network_operations unix_net_ops;
 * Time operations, like network operations above, are encapsulated.
 * They may live in their own time-<name> subdirectory.
 *
- * Maybe this structure will need updating, to pass ppi as well
+ * If "set" receives a NULL time value, it should update the TAI offset.
 */
 struct pp_time_operations {
 	int (*get)(struct pp_instance *ppi, TimeInternal *t);

--- a/proto-standard/bmc.c
+++ b/proto-standard/bmc.c
@@ -61,10 +61,12 @@ static void s1(struct pp_instance *ppi, MsgHeader *hdr, MsgAnnounce *ann)
 	/* Timeproperties DS */
 	prop->timeSource = ann->timeSource;
-	if (prop->currentUtcOffset != ann->currentUtcOffset)
+	if (prop->currentUtcOffset != ann->currentUtcOffset) {
 		pp_diag(ppi, bmc, 1, "New UTC offset: %i\n",
 			ann->currentUtcOffset);
-	prop->currentUtcOffset = ann->currentUtcOffset;
+		prop->currentUtcOffset = ann->currentUtcOffset;
+		ppi->t_ops->set(ppi, NULL);
+	}
 	/* FIXME: can't we just copy the bit keeping values? */
 	prop->currentUtcOffsetValid = ((hdr->flagField[1] & FFB_UTCV)	!= 0);

--- a/time-bare/bare-time.c
+++ b/time-bare/bare-time.c
@@ -29,6 +29,19 @@ static int bare_time_set(struct pp_instance *ppi, TimeInternal *t)
 {
 	struct bare_timeval tv;
+	if (!t) { /* Change the network notion of the utc/tai offset */
+		struct bare_timex t;
+		t.modes = MOD_TAI;
+		t.constant = DSPRO(ppi)->currentUtcOffset;
+		if (sys_adjtimex(&t) < 0)
+			pp_diag(ppi, time, 1, "Can't change TAI offset");
+		else
+			pp_diag(ppi, time, 1, "New TAI offset: %i\n", 
+				DSPRO(ppi)->currentUtcOffset);
+		return 0;
+	}
 	/* UTC = TAI - 34 */
 	tv.tv_sec = t->seconds - DSPRO(ppi)->currentUtcOffset;
 	tv.tv_usec = t->nanoseconds / 1000;

--- a/time-unix/unix-time.c
+++ b/time-unix/unix-time.c
@@ -12,6 +12,10 @@
 #include <sys/timex.h>
 #include <ppsi/ppsi.h>
+#ifndef MOD_TAI
+#define MOD_TAI 0x80
+#endif
 static void clock_fatal_error(char *context)
 {
 	pp_error("failure in \"%s\": %s\n.Exiting.\n", context,
@@ -34,10 +38,22 @@ static int unix_time_get(struct pp_instance *ppi, TimeInternal *t)
 	return 0;
 }
-static int32_t unix_time_set(struct pp_instance *ppi, TimeInternal *t)
+static int unix_time_set(struct pp_instance *ppi, TimeInternal *t)
 {
 	struct timespec tp;
+	if (!t) { /* Change the network notion of the utc/tai offset */
+		struct timex t;
+		t.modes = MOD_TAI;
+		t.constant = DSPRO(ppi)->currentUtcOffset;
+		if (adjtimex(&t) < 0)
+			clock_fatal_error("change TAI offset");
+		pp_diag(ppi, time, 1, "New TAI offset: %i\n",
+			DSPRO(ppi)->currentUtcOffset);
+		return 0;
+	}
 	/* UTC = TAI - 34 */
 	tp.tv_sec = t->seconds - DSPRO(ppi)->currentUtcOffset;
 	tp.tv_nsec = t->nanoseconds;

--- a/time-wrpc/wrpc-time.c
+++ b/time-wrpc/wrpc-time.c
@@ -29,6 +29,9 @@ static int wrpc_time_set(struct pp_instance *ppi, TimeInternal *t)
 	uint64_t sec;
 	unsigned long nsec;
+	if (!t) /* tai offset changed. We don't have it in wrpc-sw */
+		return 0;
 	sec = t->seconds;
 	nsec = t->nanoseconds;

--- a/time-wrs/wrs-time.c
+++ b/time-wrs/wrs-time.c
@@ -195,15 +195,17 @@ static int wrs_time_get(struct pp_instance *ppi, TimeInternal *t)
 	return rval;
 }
-static int32_t wrs_time_set(struct pp_instance *ppi, TimeInternal *t)
+static int wrs_time_set(struct pp_instance *ppi, TimeInternal *t)
 {
 	TimeInternal diff;
 	/*
 	 * This is almost unused in ppsi, only proto-standard/servo.c
 	 * calls it, at initialization time, when the offset is bigger
-	 * than one second.  Run this transient by just adjusting the
+	 * than one second.  Or ...
-	 * WR seconds.  Later on it will fix the nanos by ->adjust
 	 */
+	if (!t) /* ... when the utc/tai offset changes, if t is NULL */
+		return unix_time_ops.set(ppi, t);
 	pp_diag(ppi, time, 1, "%s: (weird) %9li.%09li\n", __func__,
 		(long)t->seconds, (long)t->nanoseconds);
 	/* We have no way to get the WR time, currently. So use our T3 */