revert "rtc: Add rtc_merge_alarm()"

David says "884b4aaaa242a2db8c8252796f0118164a680ab5 should be reverted.  It
added an rtc_merge_alarm() call to the 2.6.20 kernel, which hasn't yet been
used by any in-tree driver; this patch obviates the need for that call, and
uses a more robust approach."

Cc: Scott Wood <scottwood@freescale.com>
Cc: Alessandro Zummo <a.zummo@towertech.it>
Cc: David Brownell <david-b@pacbell.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

drivers/rtc/rtc-lib.c

@@ -117,85 +117,4 @@ int rtc_tm_to_time(struct rtc_time *tm, unsigned long *time)
 }
 EXPORT_SYMBOL(rtc_tm_to_time);
 
-
-/* Merge the valid (i.e. non-negative) fields of alarm into the current
- * time.  If the valid alarm fields are earlier than the equivalent
- * fields in the time, carry one into the least significant invalid
- * field, so that the alarm expiry is in the future.  It assumes that the
- * least significant invalid field is more significant than the most
- * significant valid field, and that the seconds field is valid.
- *
- * This is used by alarms that take relative (rather than absolute)
- * times, and/or have a simple binary second counter instead of
- * day/hour/minute/sec registers.
- */
-void rtc_merge_alarm(struct rtc_time *now, struct rtc_time *alarm)
-{
-	int *alarmp = &alarm->tm_sec;
-	int *timep = &now->tm_sec;
-	int carry_into, i;
-
-	/* Ignore everything past the 6th element (tm_year). */
-	for (i = 5; i > 0; i--) {
-		if (alarmp[i] < 0)
-			alarmp[i] = timep[i];
-		else
-			break;
-	}
-
-	/* No carry needed if all fields are valid. */
-	if (i == 5)
-		return;
-
-	for (carry_into = i + 1; i >= 0; i--) {
-		if (alarmp[i] < timep[i])
-			break;
-
-		if (alarmp[i] > timep[i])
-			return;
-	}
-
-	switch (carry_into) {
-		case 1:
-			alarm->tm_min++;
-
-			if (alarm->tm_min < 60)
-				return;
-
-			alarm->tm_min = 0;
-			/* fall-through */
-
-		case 2:
-			alarm->tm_hour++;
-
-			if (alarm->tm_hour < 60)
-				return;
-
-			alarm->tm_hour = 0;
-			/* fall-through */
-
-		case 3:
-			alarm->tm_mday++;
-
-			if (alarm->tm_mday <= rtc_days_in_month[alarm->tm_mon])
-				return;
-
-			alarm->tm_mday = 1;
-			/* fall-through */
-
-		case 4:
-			alarm->tm_mon++;
-
-			if (alarm->tm_mon <= 12)
-				return;
-
-			alarm->tm_mon = 1;
-			/* fall-through */
-
-		case 5:
-			alarm->tm_year++;
-	}
-}
-EXPORT_SYMBOL(rtc_merge_alarm);
-
 MODULE_LICENSE("GPL");

include/linux/rtc.h

@@ -106,7 +106,6 @@ extern int rtc_year_days(unsigned int day, unsigned int month, unsigned int year
 extern int rtc_valid_tm(struct rtc_time *tm);
 extern int rtc_tm_to_time(struct rtc_time *tm, unsigned long *time);
 extern void rtc_time_to_tm(unsigned long time, struct rtc_time *tm);
-extern void rtc_merge_alarm(struct rtc_time *now, struct rtc_time *alarm);
 
 #include <linux/device.h>
 #include <linux/seq_file.h>