[PATCH 5.10.y-cip 13/13] rtc: isl1208: Update correct procedure for clearing alarm

Biju Das
2024-07-29T15:35:39Z

commit 43696b3a9e46cf622bfeb70856b9b1cfa5a9fb23 upstream.

As per the latest HW manual[1], there is an internal delay(~250 microsec)
from setting ALME = 0 to disabling the alarm function, so the user must
add a short delay of greater than 250µs between setting ALME = 0 and
clearing ALM.

Currently setting of ALME = 0 is done after clearing the ALM, so just
reverse the operation and add a delay of 275 microsec.

[1]https://www.renesas.com/us/en/document/dst/raa215300-datasheet?r=1506351

Signed-off-by: Biju Das <biju.das.jz@bp.renesas.com>
Link: https://lore.kernel.org/r/20240618152635.48956-3-biju.das.jz@bp.renesas.com
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
Signed-off-by: Biju Das <biju.das.jz@bp.renesas.com>
---
drivers/rtc/rtc-isl1208.c | 12 +++++++-----
1 file changed, 7 insertions(+), 5 deletions(-)

diff --git a/drivers/rtc/rtc-isl1208.c b/drivers/rtc/rtc-isl1208.c
index c1824a76bc1c..c92569ec4d9a 100644
--- a/drivers/rtc/rtc-isl1208.c
+++ b/drivers/rtc/rtc-isl1208.c
@@ -663,6 +663,13 @@ isl1208_rtc_interrupt(int irq, void *data)

rtc_update_irq(isl1208->rtc, 1, RTC_IRQF | RTC_AF);

+ /* Disable the alarm */
+ err = isl1208_rtc_toggle_alarm(client, 0);
+ if (err)
+ return err;
+
+ fsleep(275);
+
/* Clear the alarm */
sr &= ~ISL1208_REG_SR_ALM;
sr = i2c_smbus_write_byte_data(client, ISL1208_REG_SR, sr);
@@ -671,11 +678,6 @@ isl1208_rtc_interrupt(int irq, void *data)
__func__);
else
handled = 1;
-
- /* Disable the alarm */
- err = isl1208_rtc_toggle_alarm(client, 0);
- if (err)
- return err;
}

if (isl1208->config->has_tamper && (sr & ISL1208_REG_SR_EVT)) {
--
2.43.0