ptp: deprecate gettime64() in favor of gettimex64()

When a driver provides gettimex64(), use it in the PTP_SYS_OFFSET ioctl
and POSIX clock's gettime() instead of gettime64(). Drivers should
provide only one of the functions.

Cc: Richard Cochran <richardcochran@gmail.com>
Cc: Jacob Keller <jacob.e.keller@intel.com>
Signed-off-by: Miroslav Lichvar <mlichvar@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/ptp/ptp_chardev.c

@@ -260,7 +260,10 @@ long ptp_ioctl(struct posix_clock *pc, unsigned int cmd, unsigned long arg)
 			pct->sec = ts.tv_sec;
 			pct->nsec = ts.tv_nsec;
 			pct++;
-			err = ptp->info->gettime64(ptp->info, &ts);
+			if (ops->gettimex64)
+				err = ops->gettimex64(ops, &ts, NULL);
+			else
+				err = ops->gettime64(ops, &ts);
 			if (err)
 				goto out;
 			pct->sec = ts.tv_sec;

drivers/ptp/ptp_clock.c

@@ -117,6 +117,9 @@ static int ptp_clock_gettime(struct posix_clock *pc, struct timespec64 *tp)
 	struct ptp_clock *ptp = container_of(pc, struct ptp_clock, clock);
 	int err;
 
+	if (ptp->info->gettimex64)
+		err = ptp->info->gettimex64(ptp->info, tp, NULL);
+	else
 		err = ptp->info->gettime64(ptp->info, tp);
 	return err;
 }

include/linux/ptp_clock_kernel.h

@@ -82,6 +82,8 @@ struct ptp_system_timestamp {
  *            parameter delta: Desired change in nanoseconds.
  *
  * @gettime64:  Reads the current time from the hardware clock.
+ *              This method is deprecated.  New drivers should implement
+ *              the @gettimex64 method instead.
  *              parameter ts: Holds the result.
  *
  * @gettimex64:  Reads the current time from the hardware clock and optionally