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rtc: mt6359: Use RTC_TC_DOW hardware register for wday

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Instead of calculating the number of full days since Sunday with
(days + 4) % 7, read (and write) that to the RTC Day-of-week Time
Counter register (RTC_TC_DOW).

Some transformation (addition and subtraction for set/get) is
still done, as this register's range is [1..7], while the tm_wday
in struct tm's range is [0..6].

Please note that this was added only to set_time() and read_time()
callbacks because set_alarm() and read_alarm() are setting a bit
in RTC_AL_MASK to ignore DOW for RTC HW alarms for unknown reasons.

Signed-off-by: AngeloGioacchino Del Regno <angelogioacchino.delregno@collabora.com>
Link: https://lore.kernel.org/r/20240923100010.97470-4-angelogioacchino.delregno@collabora.com
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
This commit is contained in:
AngeloGioacchino Del Regno 2024-09-23 12:00:10 +02:00 committed by Alexandre Belloni
parent 34bbdc12d0
commit d6f471a747
1 changed files with 6 additions and 10 deletions
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16
drivers/rtc/rtc-mt6397.c
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@ -75,6 +75,7 @@ static int __mtk_rtc_read_time(struct mt6397_rtc *rtc,
tm->tm_min = data[RTC_OFFSET_MIN];
tm->tm_hour = data[RTC_OFFSET_HOUR];
tm->tm_mday = data[RTC_OFFSET_DOM];
tm->tm_wday = data[RTC_OFFSET_DOW];
tm->tm_mon = data[RTC_OFFSET_MTH] & RTC_TC_MTH_MASK;
tm->tm_year = data[RTC_OFFSET_YEAR];
@ -86,9 +87,8 @@ exit:
static int mtk_rtc_read_time(struct device *dev, struct rtc_time *tm)
{
time64_t time;
struct mt6397_rtc *rtc = dev_get_drvdata(dev);
int days, sec, ret;
int sec, ret;
do {
ret = __mtk_rtc_read_time(rtc, tm, &sec);
@ -96,15 +96,9 @@ static int mtk_rtc_read_time(struct device *dev, struct rtc_time *tm)
goto exit;
} while (sec < tm->tm_sec);
/* HW register start mon from one, but tm_mon start from zero. */
/* HW register start mon/wday from one, but tm_mon/tm_wday start from zero. */
tm->tm_mon--;
time = rtc_tm_to_time64(tm);
/* rtc_tm_to_time64 covert Gregorian date to seconds since
* 01-01-1970 00:00:00, and this date is Thursday.
*/
days = div_s64(time, 86400);
tm->tm_wday = (days + 4) % 7;
tm->tm_wday--;
exit:
return ret;
@ -117,11 +111,13 @@ static int mtk_rtc_set_time(struct device *dev, struct rtc_time *tm)
u16 data[RTC_OFFSET_COUNT];
tm->tm_mon++;
tm->tm_wday++;
data[RTC_OFFSET_SEC] = tm->tm_sec;
data[RTC_OFFSET_MIN] = tm->tm_min;
data[RTC_OFFSET_HOUR] = tm->tm_hour;
data[RTC_OFFSET_DOM] = tm->tm_mday;
data[RTC_OFFSET_DOW] = tm->tm_wday;
data[RTC_OFFSET_MTH] = tm->tm_mon;
data[RTC_OFFSET_YEAR] = tm->tm_year;