diff options
| author | Dario Binacchi <dariobin@libero.it> | 2021-06-02 23:38:02 +0300 |
|---|---|---|
| committer | Lokesh Vutla <lokeshvutla@ti.com> | 2021-06-09 19:53:44 +0300 |
| commit | c7c7c8db00ace48f538f4b51d606cd6e4f537df1 (patch) | |
| tree | ddad8ca0d3ae0935c932acc70bd95b6bb349f04d /drivers/rtc | |
| parent | 79250ef3e263ef23c16c3c06a50834f0dcca4426 (diff) | |
| download | u-boot-c7c7c8db00ace48f538f4b51d606cd6e4f537df1.tar.xz | |
rtc: davinci: use unlock/lock mechanism
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>
Signed-off-by: Lokesh Vutla <lokeshvutla@ti.com>
Link: https://lore.kernel.org/r/20210602203805.11494-6-dariobin@libero.it
Diffstat (limited to 'drivers/rtc')
| -rw-r--r-- | drivers/rtc/davinci.c | 14 |
1 files changed, 14 insertions, 0 deletions
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, |