Re: [RFC 17/18] mfd: max14577: Do not enforce (incorrect) interrupt trigger type
From: Rob Herring
Date: Mon Dec 21 2020 - 13:48:20 EST
On Thu, 10 Dec 2020 22:25:33 +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 14577/77836 datasheets describe 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 charger 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/mfd/max14577.txt | 4 ++--
> drivers/mfd/max14577.c | 6 +++---
> 2 files changed, 5 insertions(+), 5 deletions(-)
>
Acked-by: Rob Herring <robh@xxxxxxxxxx>