From 742b0d7e15c333303daad4856de0764f4bc83601 Mon Sep 17 00:00:00 2001
From: Krzysztof Kozlowski <krzk@kernel.org>
Date: Wed, 26 May 2021 13:20:34 -0400
Subject: [PATCH] rtc: max77686: Do not enforce (incorrect) interrupt trigger type
Git-commit: 742b0d7e15c333303daad4856de0764f4bc83601
Patch-mainline: v5.14-rc1
References: git-fixes

Interrupt line can be configured on different hardware in different way,
even inverted.  Therefore driver should not enforce specific trigger
type - edge falling - but instead rely on Devicetree to configure it.

The Maxim 77686 datasheet describes the interrupt line as active low
with a requirement of acknowledge from the CPU therefore the edge
falling is not correct.

The interrupt line is shared between PMIC and RTC driver, so using level
sensitive interrupt is here especially important to avoid races.  With
an edge configuration in case if first PMIC signals interrupt followed
shortly after by the RTC, the interrupt might not be yet cleared/acked
thus the second one would not be noticed.

Signed-off-by: Krzysztof Kozlowski <krzk@kernel.org>
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
Link: https://lore.kernel.org/r/20210526172036.183223-6-krzysztof.kozlowski@canonical.com
Acked-by: Takashi Iwai <tiwai@suse.de>

---
 drivers/rtc/rtc-max77686.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/rtc/rtc-max77686.c b/drivers/rtc/rtc-max77686.c
index d51cc12114cb..eae7cb9faf1e 100644
--- a/drivers/rtc/rtc-max77686.c
+++ b/drivers/rtc/rtc-max77686.c
@@ -717,8 +717,8 @@ static int max77686_init_rtc_regmap(struct max77686_rtc_info *info)
 
 add_rtc_irq:
 	ret = regmap_add_irq_chip(info->rtc_regmap, info->rtc_irq,
-				  IRQF_TRIGGER_FALLING | IRQF_ONESHOT |
-				  IRQF_SHARED, 0, info->drv_data->rtc_irq_chip,
+				  IRQF_ONESHOT | IRQF_SHARED,
+				  0, info->drv_data->rtc_irq_chip,
 				  &info->rtc_irq_data);
 	if (ret < 0) {
 		dev_err(info->dev, "Failed to add RTC irq chip: %d\n", ret);
-- 
2.26.2