1 files changed, 58 insertions, 9 deletions

diff --git a/drivers/rtc/rtc-lib.c b/drivers/rtc/rtc-lib.c
index cfedc1d28ee..c4cf0573111 100644
--- a/drivers/rtc/rtc-lib.c
+++ b/drivers/rtc/rtc-lib.c
@@ -18,24 +18,43 @@ static const unsigned char rtc_days_in_month[] = {
 	31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31
 };
 
+static const unsigned short rtc_ydays[2][13] = {
+	/* Normal years */
+	{ 0, 31, 59, 90, 120, 151, 181, 212, 243, 273, 304, 334, 365 },
+	/* Leap years */
+	{ 0, 31, 60, 91, 121, 152, 182, 213, 244, 274, 305, 335, 366 }
+};
+
 #define LEAPS_THRU_END_OF(y) ((y)/4 - (y)/100 + (y)/400)
-#define LEAP_YEAR(year) ((!(year % 4) && (year % 100)) || !(year % 400))
 
+/*
+ * The number of days in the month.
+ */
 int rtc_month_days(unsigned int month, unsigned int year)
 {
-	return rtc_days_in_month[month] + (LEAP_YEAR(year) && month == 1);
+	return rtc_days_in_month[month] + (is_leap_year(year) && month == 1);
 }
 EXPORT_SYMBOL(rtc_month_days);
 
 /*
+ * The number of days since January 1. (0 to 365)
+ */
+int rtc_year_days(unsigned int day, unsigned int month, unsigned int year)
+{
+	return rtc_ydays[is_leap_year(year)][month] + day-1;
+}
+EXPORT_SYMBOL(rtc_year_days);
+
+/*
  * Convert seconds since 01-01-1970 00:00:00 to Gregorian date.
  */
 void rtc_time_to_tm(unsigned long time, struct rtc_time *tm)
 {
-	register int days, month, year;
+	unsigned int month, year;
+	int days;
 
 	days = time / 86400;
-	time -= days * 86400;
+	time -= (unsigned int) days * 86400;
 
 	/* day of the week, 1970-01-01 was a Thursday */
 	tm->tm_wday = (days + 4) % 7;
@@ -46,7 +65,7 @@ void rtc_time_to_tm(unsigned long time, struct rtc_time *tm)
 		- LEAPS_THRU_END_OF(1970 - 1);
 	if (days < 0) {
 		year -= 1;
-		days += 365 + LEAP_YEAR(year);
+		days += 365 + is_leap_year(year);
 	}
 	tm->tm_year = year - 1900;
 	tm->tm_yday = days + 1;
@@ -66,6 +85,8 @@ void rtc_time_to_tm(unsigned long time, struct rtc_time *tm)
 	time -= tm->tm_hour * 3600;
 	tm->tm_min = time / 60;
 	tm->tm_sec = time - tm->tm_min * 60;
+
+	tm->tm_isdst = 0;
 }
 EXPORT_SYMBOL(rtc_time_to_tm);
 
@@ -75,12 +96,12 @@ EXPORT_SYMBOL(rtc_time_to_tm);
 int rtc_valid_tm(struct rtc_time *tm)
 {
 	if (tm->tm_year < 70
-		|| tm->tm_mon >= 12
+		|| ((unsigned)tm->tm_mon) >= 12
 		|| tm->tm_mday < 1
 		|| tm->tm_mday > rtc_month_days(tm->tm_mon, tm->tm_year + 1900)
-		|| tm->tm_hour >= 24
-		|| tm->tm_min >= 60
-		|| tm->tm_sec >= 60)
+		|| ((unsigned)tm->tm_hour) >= 24
+		|| ((unsigned)tm->tm_min) >= 60
+		|| ((unsigned)tm->tm_sec) >= 60)
 		return -EINVAL;
 
 	return 0;
@@ -98,4 +119,32 @@ int rtc_tm_to_time(struct rtc_time *tm, unsigned long *time)
 }
 EXPORT_SYMBOL(rtc_tm_to_time);
 
+/*
+ * Convert rtc_time to ktime
+ */
+ktime_t rtc_tm_to_ktime(struct rtc_time tm)
+{
+	time_t time;
+	rtc_tm_to_time(&tm, &time);
+	return ktime_set(time, 0);
+}
+EXPORT_SYMBOL_GPL(rtc_tm_to_ktime);
+
+/*
+ * Convert ktime to rtc_time
+ */
+struct rtc_time rtc_ktime_to_tm(ktime_t kt)
+{
+	struct timespec ts;
+	struct rtc_time ret;
+
+	ts = ktime_to_timespec(kt);
+	/* Round up any ns */
+	if (ts.tv_nsec)
+		ts.tv_sec++;
+	rtc_time_to_tm(ts.tv_sec, &ret);
+	return ret;
+}
+EXPORT_SYMBOL_GPL(rtc_ktime_to_tm);
+
 MODULE_LICENSE("GPL");