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Diffstat (limited to 'kernel/include/asm-generic/rtc.h')
-rw-r--r--kernel/include/asm-generic/rtc.h29
1 files changed, 29 insertions, 0 deletions
diff --git a/kernel/include/asm-generic/rtc.h b/kernel/include/asm-generic/rtc.h
index fa86f240c..4e3b65583 100644
--- a/kernel/include/asm-generic/rtc.h
+++ b/kernel/include/asm-generic/rtc.h
@@ -16,6 +16,9 @@
#include <linux/rtc.h>
#include <linux/bcd.h>
#include <linux/delay.h>
+#ifdef CONFIG_ACPI
+#include <linux/acpi.h>
+#endif
#define RTC_PIE 0x40 /* periodic interrupt enable */
#define RTC_AIE 0x20 /* alarm interrupt enable */
@@ -46,6 +49,7 @@ static inline unsigned int __get_rtc_time(struct rtc_time *time)
{
unsigned char ctrl;
unsigned long flags;
+ unsigned char century = 0;
#ifdef CONFIG_MACH_DECSTATION
unsigned int real_year;
@@ -79,6 +83,11 @@ static inline unsigned int __get_rtc_time(struct rtc_time *time)
#ifdef CONFIG_MACH_DECSTATION
real_year = CMOS_READ(RTC_DEC_YEAR);
#endif
+#ifdef CONFIG_ACPI
+ if (acpi_gbl_FADT.header.revision >= FADT2_REVISION_ID &&
+ acpi_gbl_FADT.century)
+ century = CMOS_READ(acpi_gbl_FADT.century);
+#endif
ctrl = CMOS_READ(RTC_CONTROL);
spin_unlock_irqrestore(&rtc_lock, flags);
@@ -90,12 +99,16 @@ static inline unsigned int __get_rtc_time(struct rtc_time *time)
time->tm_mday = bcd2bin(time->tm_mday);
time->tm_mon = bcd2bin(time->tm_mon);
time->tm_year = bcd2bin(time->tm_year);
+ century = bcd2bin(century);
}
#ifdef CONFIG_MACH_DECSTATION
time->tm_year += real_year - 72;
#endif
+ if (century)
+ time->tm_year += (century - 19) * 100;
+
/*
* Account for differences between how the RTC uses the values
* and how they are defined in a struct rtc_time;
@@ -122,6 +135,7 @@ static inline int __set_rtc_time(struct rtc_time *time)
#ifdef CONFIG_MACH_DECSTATION
unsigned int real_yrs, leap_yr;
#endif
+ unsigned char century = 0;
yrs = time->tm_year;
mon = time->tm_mon + 1; /* tm_mon starts at zero */
@@ -150,6 +164,15 @@ static inline int __set_rtc_time(struct rtc_time *time)
yrs = 73;
}
#endif
+
+#ifdef CONFIG_ACPI
+ if (acpi_gbl_FADT.header.revision >= FADT2_REVISION_ID &&
+ acpi_gbl_FADT.century) {
+ century = (yrs + 1900) / 100;
+ yrs %= 100;
+ }
+#endif
+
/* These limits and adjustments are independent of
* whether the chip is in binary mode or not.
*/
@@ -169,6 +192,7 @@ static inline int __set_rtc_time(struct rtc_time *time)
day = bin2bcd(day);
mon = bin2bcd(mon);
yrs = bin2bcd(yrs);
+ century = bin2bcd(century);
}
save_control = CMOS_READ(RTC_CONTROL);
@@ -185,6 +209,11 @@ static inline int __set_rtc_time(struct rtc_time *time)
CMOS_WRITE(hrs, RTC_HOURS);
CMOS_WRITE(min, RTC_MINUTES);
CMOS_WRITE(sec, RTC_SECONDS);
+#ifdef CONFIG_ACPI
+ if (acpi_gbl_FADT.header.revision >= FADT2_REVISION_ID &&
+ acpi_gbl_FADT.century)
+ CMOS_WRITE(century, acpi_gbl_FADT.century);
+#endif
CMOS_WRITE(save_control, RTC_CONTROL);
CMOS_WRITE(save_freq_select, RTC_FREQ_SELECT);