The RTC module contains a kicker mechanism to prevent any spurious writes from changing the register values. To set the time, you must first unlock the TC registers, update them and then lock.
Signed-off-by: Dario Binacchi dariobin@libero.it ---
drivers/rtc/davinci.c | 14 ++++++++++++++ 1 file changed, 14 insertions(+)
diff --git a/drivers/rtc/davinci.c b/drivers/rtc/davinci.c index 7b8c729f3b..82e5eb3b43 100644 --- a/drivers/rtc/davinci.c +++ b/drivers/rtc/davinci.c @@ -16,6 +16,18 @@ #define RTC_BASE DAVINCI_RTC_BASE #endif
+static void davinci_rtc_lock(struct davinci_rtc *rtc) +{ + writel(0, &rtc->kick0r); + writel(0, &rtc->kick1r); +} + +static void davinci_rtc_unlock(struct davinci_rtc *rtc) +{ + writel(RTC_KICK0R_WE, &rtc->kick0r); + writel(RTC_KICK1R_WE, &rtc->kick1r); +} + static int davinci_rtc_wait_not_busy(struct davinci_rtc *rtc) { int count; @@ -89,6 +101,7 @@ int rtc_set(struct rtc_time *tmp) if (ret) return ret;
+ davinci_rtc_unlock(rtc); writeb(bin2bcd(tmp->tm_year % 100), &rtc->year); writeb(bin2bcd(tmp->tm_mon), &rtc->month);
@@ -97,6 +110,7 @@ int rtc_set(struct rtc_time *tmp) writeb(bin2bcd(tmp->tm_hour), &rtc->hours); writeb(bin2bcd(tmp->tm_min), &rtc->minutes); writeb(bin2bcd(tmp->tm_sec), &rtc->second); + davinci_rtc_lock(rtc);
debug("Set DATE: %4d-%02d-%02d (wday=%d) TIME: %2d:%02d:%02d\n", tmp->tm_year, tmp->tm_mon, tmp->tm_mday, tmp->tm_wday,