rtc-x1205: fix rtc_time to y2k register value conversion
The possible CCR_Y2K register values are 19 or 20 and struct rtc_time's
tm_year is in years since 1900.
The function translating rtc_time to register values assumes tm_year to be
years since first christmas, though, and we end up storing 0 or 1 in the
CCR_Y2K register, which the hardware does not refuse to do.
A subsequent probing of the clock fails due to the invalid value range in
the register, though.
[ And if it didn't, reading the clock would yield a bogus year because
the function translating registers to tm_year is assuming a register
value of 19 or 20. ]
This fixes the conversion from years since 1900 in tm_year to the
corresponding CCR_Y2K value of 19 or 20.
Signed-off-by: Johannes Weiner <jw@emlix.com>
Cc: Alessandro Zummo <a.zummo@towertech.it>
Cc: Paul Gortmaker <p_gortmaker@yahoo.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/drivers/rtc/rtc-x1205.c b/drivers/rtc/rtc-x1205.c
index 310c107..cc9ba47 100644
--- a/drivers/rtc/rtc-x1205.c
+++ b/drivers/rtc/rtc-x1205.c
@@ -195,7 +195,7 @@
/* year, since the rtc epoch*/
buf[CCR_YEAR] = bin2bcd(tm->tm_year % 100);
buf[CCR_WDAY] = tm->tm_wday & 0x07;
- buf[CCR_Y2K] = bin2bcd(tm->tm_year / 100);
+ buf[CCR_Y2K] = bin2bcd((tm->tm_year + 1900) / 100);
}
/* If writing alarm registers, set compare bits on registers 0-4 */