rtc: stm32: manage 2 digit limitation on year

STM32 RTC manages only 2 digits for YEAR
(Year tens and units in BCD format in RTC_DR register).

With this patch, RTC driver assumes that tm->tm_years is between
2000 and 2099; tm->tm_year - 2000 have only 2 digit
(0 > and <= 99).

Signed-off-by: Patrick Delaunay <patrick.delaunay@st.com>

diff --git a/drivers/rtc/stm32_rtc.c b/drivers/rtc/stm32_rtc.c
index abd339076ad25c5b86232b87230a2fbc2915f5ac..26747144425fcae995016a85cb424be913bac704 100644 (file)
--- a/drivers/rtc/stm32_rtc.c
+++ b/drivers/rtc/stm32_rtc.c
@@ -72,7 +72,8 @@ static int stm32_rtc_get(struct udevice *dev, struct rtc_time *tm)
 
        tm->tm_mday = bcd2bin((dr & STM32_RTC_DATE) >> STM32_RTC_DATE_SHIFT);
        tm->tm_mon = bcd2bin((dr & STM32_RTC_MONTH) >> STM32_RTC_MONTH_SHIFT);
-       tm->tm_year = bcd2bin((dr & STM32_RTC_YEAR) >> STM32_RTC_YEAR_SHIFT);
+       tm->tm_year = 2000 +
+                     bcd2bin((dr & STM32_RTC_YEAR) >> STM32_RTC_YEAR_SHIFT);
        tm->tm_wday = bcd2bin((dr & STM32_RTC_WDAY) >> STM32_RTC_WDAY_SHIFT);
        tm->tm_yday = 0;
        tm->tm_isdst = 0;
@@ -174,6 +175,9 @@ static int stm32_rtc_set(struct udevice *dev, const struct rtc_time *tm)
                tm->tm_year, tm->tm_mon, tm->tm_mday, tm->tm_wday,
                tm->tm_hour, tm->tm_min, tm->tm_sec);
 
+       if (tm->tm_year < 2000 || tm->tm_year > 2099)
+               return -EINVAL;
+
        /* Time in BCD format */
        t = (bin2bcd(tm->tm_sec) << STM32_RTC_SEC_SHIFT) & STM32_RTC_SEC;
        t |= (bin2bcd(tm->tm_min) << STM32_RTC_MIN_SHIFT) & STM32_RTC_MIN;
@@ -182,7 +186,8 @@ static int stm32_rtc_set(struct udevice *dev, const struct rtc_time *tm)
        /* Date in BCD format */
        d = (bin2bcd(tm->tm_mday) << STM32_RTC_DATE_SHIFT) & STM32_RTC_DATE;
        d |= (bin2bcd(tm->tm_mon) << STM32_RTC_MONTH_SHIFT) & STM32_RTC_MONTH;
-       d |= (bin2bcd(tm->tm_year) << STM32_RTC_YEAR_SHIFT) & STM32_RTC_YEAR;
+       d |= (bin2bcd(tm->tm_year - 2000) << STM32_RTC_YEAR_SHIFT) &
+             STM32_RTC_YEAR;
        d |= (bin2bcd(tm->tm_wday) << STM32_RTC_WDAY_SHIFT) & STM32_RTC_WDAY;
 
        return stm32_rtc_set_time(dev, t, d);