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 Beno?t Th?baudeau <[email protected]>

Cc Wolfgang Denk <[email protected]>

---
 .../drivers/rtc/pcf8563.c                          |    4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

(quoted diff) +0 -0

u-boot-66714b1/drivers/rtc/pcf8563.c
index 339e5f6..a028533 100644

drivers/rtc/pcf8563.c +1 -1

@@ -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;

Quoted 51 lines · Beno?t Th?baudeau

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 Beno?t Th?baudeau <[email protected]>

Cc Wolfgang Denk <[email protected]>

---
 .../drivers/rtc/pcf8563.c                          |    4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

(quoted diff) +0 -0

u-boot-66714b1/drivers/rtc/pcf8563.c
index 339e5f6..a028533 100644

drivers/rtc/pcf8563.c +1 -1

@@ -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);

drivers/rtc/pcf8563.c +0 -0

 	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));
 

drivers/rtc/pcf8563.c int rtc_set (struct rtc_time *tmp) · line 100

Quoted 6 lines

drivers/rtc/pcf8563.c +1 -1

-	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));

Ping?

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 RTC85> 64, make this driver compatible with Linux's by giving the opposite meaning to > the century bit.

Signed-off-by Beno?t Th?baudeau <[email protected]>

Cc Wolfgang Denk <[email protected]>

---
 .../drivers/rtc/pcf8563.c                          |    4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)