From: Benoît Thébaudeau <benoit.thebaudeau@advansee.com>
Date: Fri, 20 Jul 2012 14:05:36 +0000 (+0200)
Subject: rtc: pcf8563: Make century compatible with Linux
X-Git-Tag: v2012.10-rc1~85
X-Git-Url: http://review.tizen.org/git/?a=commitdiff_plain;h=df930e9b3c6a644d1b0b50dce31fc9f4686925c2;p=kernel%2Fu-boot.git

rtc: pcf8563: Make century compatible with Linux

This driver uses the century bit of this RTC in the opposite way Linux does.
From Linux's rtc-pcf8563.c:
	/*
	 * The meaning of MO_C bit varies by the chip type.
	 * From PCF8563 datasheet: this bit is toggled when the years
	 * register overflows from 99 to 00
	 *   0 indicates the century is 20xx
	 *   1 indicates the century is 19xx
	 * From RTC8564 datasheet: this bit indicates change of
	 * century. When the year digit data overflows from 99 to 00,
	 * this bit is set. By presetting it to 0 while still in the
	 * 20th century, it will be set in year 2000, ...
	 * There seems no reliable way to know how the system use this
	 * bit.  So let's do it heuristically, assuming we are live in
	 * 1970...2069.
	 */

As U-Boot's PCF8563 driver does not say it is supposed to support the RTC8564,
make this driver compatible with Linux's by giving the opposite meaning to the
century bit.

Signed-off-by: Benoît Thébaudeau <benoit.thebaudeau@advansee.com>
Cc: Wolfgang Denk <wd@denx.de>
---

diff --git a/drivers/rtc/pcf8563.c b/drivers/rtc/pcf8563.c
index 339e5f6..a028533 100644
--- a/drivers/rtc/pcf8563.c
+++ b/drivers/rtc/pcf8563.c
@@ -72,7 +72,7 @@ int rtc_get (struct rtc_time *tmp)
 	tmp->tm_hour = bcd2bin (hour & 0x3F);
 	tmp->tm_mday = bcd2bin (mday & 0x3F);
 	tmp->tm_mon  = bcd2bin (mon_cent & 0x1F);
-	tmp->tm_year = bcd2bin (year) + ((mon_cent & 0x80) ? 2000 : 1900);
+	tmp->tm_year = bcd2bin (year) + ((mon_cent & 0x80) ? 1900 : 2000);
 	tmp->tm_wday = bcd2bin (wday & 0x07);
 	tmp->tm_yday = 0;
 	tmp->tm_isdst= 0;
@@ -94,7 +94,7 @@ int rtc_set (struct rtc_time *tmp)
 
 	rtc_write (0x08, bin2bcd(tmp->tm_year % 100));
 
-	century = (tmp->tm_year >= 2000) ? 0x80 : 0;
+	century = (tmp->tm_year >= 2000) ? 0 : 0x80;
 	rtc_write (0x07, bin2bcd(tmp->tm_mon) | century);
 
 	rtc_write (0x06, bin2bcd(tmp->tm_wday));