Re: [RFC 13/18] mfd: max77686: Do not enforce (incorrect) interrupt trigger type
From: Rob Herring
Date: Mon Dec 21 2020 - 13:46:30 EST
On Thu, 10 Dec 2020 22:25:29 +0100, Krzysztof Kozlowski wrote:
> 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@xxxxxxxxxx>
>
> ---
>
> This patch should wait till DTS changes are merged, as it relies on
> proper Devicetree.
> ---
> 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(-)
>
Acked-by: Rob Herring <robh@xxxxxxxxxx>