Thread (9 messages) 9 messages, 2 authors, 2021-09-28

Re: [RESEND PATCH v2 2/4] mfd: max77686: Do not enforce (incorrect) interrupt trigger type

From: Lee Jones <hidden>
Date: 2021-09-28 09:53:15
Also in: linux-clk, linux-samsung-soc, lkml

On Wed, 02 Jun 2021, Krzysztof Kozlowski wrote:
From: Krzysztof Kozlowski <krzk@kernel.org>

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>
Acked-by: Rob Herring <robh@kernel.org>

---

Changes since v1:
1. Add ack.
---
 Documentation/devicetree/bindings/clock/maxim,max77686.txt | 4 ++--
 Documentation/devicetree/bindings/mfd/max77686.txt         | 2 +-
 Documentation/devicetree/bindings/regulator/max77686.txt   | 2 +-
 drivers/mfd/max77686.c                                     | 3 +--
 4 files changed, 5 insertions(+), 6 deletions(-)
Applied, thanks.

-- 
Lee Jones [李琼斯]
Senior Technical Lead - Developer Services
Linaro.org │ Open source software for Arm SoCs
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