Sylvain Chouleur <sylvain.chouleur@xxxxxxxxx> writes:
> If century field is supported by the RTC CMOS device, then we should use
> it and do not consider years greater that 169 as an error.
>
> For information, the year field of the rtc_time structure contains the
> value to add to 1970 to obtain the current year.
> This was a hack to be able to support years from 1970 to 2069.
> This patch remains compatible with this implementation.
>
> Signed-off-by: Sylvain Chouleur <sylvain.chouleur@xxxxxxxxx>
> ---
> include/asm-generic/rtc.h | 29 +++++++++++++++++++++++++++++
> 1 file changed, 29 insertions(+)
>
> diff --git a/include/asm-generic/rtc.h b/include/asm-generic/rtc.h
> index fa86f240c874..4e3b6558331e 100644
> --- a/include/asm-generic/rtc.h
> +++ b/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);
> --
> 1.9.1
Any thought about this patch?
Thanks
--
Sylvain
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