| Message ID | 20250109-enable-rtc-v1-2-e8223bf55bb8@baylibre.com (mailing list archive) |
|---|---|
| State | New |
| Headers | show |
| Series | Enable RTC for the MT6357 | expand |
On 09/01/2025 16:29:52+0100, Alexandre Mergnat wrote: > Removing the RTC_MIN_YEAR_OFFSET addition and subtraction has > introduced a regression. > > ~# hwclock -r --verbose > hwclock from util-linux 2.37.4 > System Time: 1262312013.143552 > Trying to open: /dev/rtc0 > Using the rtc interface to the clock. > Assuming hardware clock is kept in UTC time. > Waiting for clock tick... > hwclock: select() to /dev/rtc0 to wait for clock tick timed out > ...synchronization failed > > Bring back the RTC_MIN_YEAR_OFFSET to fix the RTC. > NAK, you'd have to investigate a bit more, I want to get rid of the RTC_MIN_YEAR_OFFSET insanity. > Fixes: 34bbdc12d04e ("rtc: mt6359: Add RTC hardware range and add support for start-year") > Signed-off-by: Alexandre Mergnat <amergnat@baylibre.com> > --- > drivers/rtc/rtc-mt6397.c | 9 +++++++++ > 1 file changed, 9 insertions(+) > > diff --git a/drivers/rtc/rtc-mt6397.c b/drivers/rtc/rtc-mt6397.c > index 55e75712edd4..9930b6bdb6ca 100644 > --- a/drivers/rtc/rtc-mt6397.c > +++ b/drivers/rtc/rtc-mt6397.c > @@ -96,6 +96,12 @@ static int mtk_rtc_read_time(struct device *dev, struct rtc_time *tm) > goto exit; > } while (sec < tm->tm_sec); > > + /* HW register use 7 bits to store year data, minus > + * RTC_MIN_YEAR_OFFSET before write year data to register, and plus > + * RTC_MIN_YEAR_OFFSET back after read year from register > + */ > + tm->tm_year += RTC_MIN_YEAR_OFFSET; > + > /* HW register start mon/wday from one, but tm_mon/tm_wday start from zero. */ > tm->tm_mon--; > tm->tm_wday--; > @@ -110,6 +116,7 @@ static int mtk_rtc_set_time(struct device *dev, struct rtc_time *tm) > int ret; > u16 data[RTC_OFFSET_COUNT]; > > + tm->tm_year -= RTC_MIN_YEAR_OFFSET; > tm->tm_mon++; > tm->tm_wday++; > > @@ -167,6 +174,7 @@ static int mtk_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *alm) > tm->tm_mon = data[RTC_OFFSET_MTH] & RTC_AL_MTH_MASK; > tm->tm_year = data[RTC_OFFSET_YEAR] & RTC_AL_YEA_MASK; > > + tm->tm_year += RTC_MIN_YEAR_OFFSET; > tm->tm_mon--; > > return 0; > @@ -182,6 +190,7 @@ static int mtk_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *alm) > int ret; > u16 data[RTC_OFFSET_COUNT]; > > + tm->tm_year -= RTC_MIN_YEAR_OFFSET; > tm->tm_mon++; > > mutex_lock(&rtc->lock); > > -- > 2.25.1 >
diff --git a/drivers/rtc/rtc-mt6397.c b/drivers/rtc/rtc-mt6397.c index 55e75712edd4..9930b6bdb6ca 100644 --- a/drivers/rtc/rtc-mt6397.c +++ b/drivers/rtc/rtc-mt6397.c @@ -96,6 +96,12 @@ static int mtk_rtc_read_time(struct device *dev, struct rtc_time *tm) goto exit; } while (sec < tm->tm_sec); + /* HW register use 7 bits to store year data, minus + * RTC_MIN_YEAR_OFFSET before write year data to register, and plus + * RTC_MIN_YEAR_OFFSET back after read year from register + */ + tm->tm_year += RTC_MIN_YEAR_OFFSET; + /* HW register start mon/wday from one, but tm_mon/tm_wday start from zero. */ tm->tm_mon--; tm->tm_wday--; @@ -110,6 +116,7 @@ static int mtk_rtc_set_time(struct device *dev, struct rtc_time *tm) int ret; u16 data[RTC_OFFSET_COUNT]; + tm->tm_year -= RTC_MIN_YEAR_OFFSET; tm->tm_mon++; tm->tm_wday++; @@ -167,6 +174,7 @@ static int mtk_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *alm) tm->tm_mon = data[RTC_OFFSET_MTH] & RTC_AL_MTH_MASK; tm->tm_year = data[RTC_OFFSET_YEAR] & RTC_AL_YEA_MASK; + tm->tm_year += RTC_MIN_YEAR_OFFSET; tm->tm_mon--; return 0; @@ -182,6 +190,7 @@ static int mtk_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *alm) int ret; u16 data[RTC_OFFSET_COUNT]; + tm->tm_year -= RTC_MIN_YEAR_OFFSET; tm->tm_mon++; mutex_lock(&rtc->lock);
Removing the RTC_MIN_YEAR_OFFSET addition and subtraction has introduced a regression. ~# hwclock -r --verbose hwclock from util-linux 2.37.4 System Time: 1262312013.143552 Trying to open: /dev/rtc0 Using the rtc interface to the clock. Assuming hardware clock is kept in UTC time. Waiting for clock tick... hwclock: select() to /dev/rtc0 to wait for clock tick timed out ...synchronization failed Bring back the RTC_MIN_YEAR_OFFSET to fix the RTC. Fixes: 34bbdc12d04e ("rtc: mt6359: Add RTC hardware range and add support for start-year") Signed-off-by: Alexandre Mergnat <amergnat@baylibre.com> --- drivers/rtc/rtc-mt6397.c | 9 +++++++++ 1 file changed, 9 insertions(+)