[PATCH V4 1/2] rtc-pm8xxx: clear the triggered alarm interrupt during driver probe

[jianbin zhang]

If the alarm is triggered before the driver gets probed, the alarm interrupt
will be missed and it won't be detected, and the stale alarm settings will
be still retained because of not being cleared.

Issue reproduce step:
(1) set the alarm and poweroff the device
(2) alarm happens and the device boots
(3) poweroff the device again
(4) alarm irq not be cleard, device boots again

the fixing here is clear the interrupt during the step(3) unconditionally.

Signed-off-by: jianbin zhang <quic_jianbinz@xxxxxxxxxxx>
---
Changes in v4:
- add the cover letter
- modify the patch to conform to the specification

Changes in v3:
- clear the interrupt in driver probe unconditionally
- link: https://lore.kernel.org/linux-rtc/20240319191037.GA3796206@xxxxxxxxxxxxxxxxxxxxxxxxxxx/T/#t

Changes in v2:
- Adapt the V1 patch according to the newest rtc-pm8xxx
- link: https://lore.kernel.org/linux-rtc/20240124024023df15ef6e@mail.local/

Changes in v1:
- fixing is as below logic, During driver probe: read ALARM_EN, read ALARM_DATA, read RTC_RDATA,
  if (ALARM_DATA < RTC_DATA), Trigger the alarm event and clear the alarm settins
- link: https://lore.kernel.org/linux-rtc/20220321090514.4523-1-quic_jianbinz@xxxxxxxxxxx/

Changes in original:
- link to original: https://lore.kernel.org/linux-rtc/YTusgJlMUdXOKQaL@xxxxxxxxx/
---
 drivers/rtc/rtc-pm8xxx.c | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/drivers/rtc/rtc-pm8xxx.c b/drivers/rtc/rtc-pm8xxx.c
index f6b779c12ca7..e4e2307445cf 100644
--- a/drivers/rtc/rtc-pm8xxx.c
+++ b/drivers/rtc/rtc-pm8xxx.c
@@ -527,6 +527,11 @@ static int pm8xxx_rtc_probe(struct platform_device *pdev)
 	if (rc)
 		return rc;
 
+	rc = regmap_update_bits(rtc_dd->regmap, rtc_dd->regs->alarm_ctrl2,
+					  PM8xxx_RTC_ALARM_CLEAR, 1);
+	if (rc)
+		return rc;
+
 	return 0;
 }
 

-- 
2.43.2