[PATCH 212/222] drivers/rtc/rtc-vt8500.c: fix handling of data passed in struct rtc_time

[Herton Ronaldo Krzesinski]

3.5.7.3 -stable review patch.  If anyone has any objections, please let me know.

------------------

From: Tony Prisk <linux at prisktech.co.nz>

commit 2f90b68309683f2c5765a1b04ca23d71e51f1494 upstream.

tm_mon is 0..11, whereas vt8500 expects 1..12 for the month field,
causing invalid date errors for January, and causing the day field to
roll over incorrectly.

The century flag is only handled in vt8500_rtc_read_time, but not set in
vt8500_rtc_set_time.  This patch corrects the behaviour of the century
flag.

Signed-off-by: Edgar Toernig <froese at gmx.de>
Signed-off-by: Tony Prisk <linux at prisktech.co.nz>
Signed-off-by: Andrew Morton <akpm at linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds at linux-foundation.org>
Signed-off-by: Herton Ronaldo Krzesinski <herton.krzesinski at canonical.com>
---
 drivers/rtc/rtc-vt8500.c |    7 ++++---
 1 file changed, 4 insertions(+), 3 deletions(-)

diff --git a/drivers/rtc/rtc-vt8500.c b/drivers/rtc/rtc-vt8500.c
index 5641ac5..44878da 100644
--- a/drivers/rtc/rtc-vt8500.c
+++ b/drivers/rtc/rtc-vt8500.c
@@ -118,7 +118,7 @@ static int vt8500_rtc_read_time(struct device *dev, struct rtc_time *tm)
 	tm->tm_min = bcd2bin((time & TIME_MIN_MASK) >> TIME_MIN_S);
 	tm->tm_hour = bcd2bin((time & TIME_HOUR_MASK) >> TIME_HOUR_S);
 	tm->tm_mday = bcd2bin(date & DATE_DAY_MASK);
-	tm->tm_mon = bcd2bin((date & DATE_MONTH_MASK) >> DATE_MONTH_S);
+	tm->tm_mon = bcd2bin((date & DATE_MONTH_MASK) >> DATE_MONTH_S) - 1;
 	tm->tm_year = bcd2bin((date & DATE_YEAR_MASK) >> DATE_YEAR_S)
 			+ ((date >> DATE_CENTURY_S) & 1 ? 200 : 100);
 	tm->tm_wday = (time & TIME_DOW_MASK) >> TIME_DOW_S;
@@ -137,8 +137,9 @@ static int vt8500_rtc_set_time(struct device *dev, struct rtc_time *tm)
 	}
 
 	writel((bin2bcd(tm->tm_year - 100) << DATE_YEAR_S)
-		| (bin2bcd(tm->tm_mon) << DATE_MONTH_S)
-		| (bin2bcd(tm->tm_mday)),
+		| (bin2bcd(tm->tm_mon + 1) << DATE_MONTH_S)
+		| (bin2bcd(tm->tm_mday))
+		| ((tm->tm_year >= 200) << DATE_CENTURY_S),
 		vt8500_rtc->regbase + VT8500_RTC_DS);
 	writel((bin2bcd(tm->tm_wday) << TIME_DOW_S)
 		| (bin2bcd(tm->tm_hour) << TIME_HOUR_S)
-- 
1.7.9.5