[RFC 13/18] mfd: max77686: Do not enforce (incorrect) interrupt trigger type

[Rob Herring]

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 at kernel.org>
> 
> ---
> 
> 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 at kernel.org>