Re: [PATCH] gpio: mcp23s08: support setting pullups from device tree data

[Alexander Stein <alexander.stein@systec-electronic.com>]

On Friday 04 December 2015 13:46:13, Timo Teräs wrote:
> Make pullup configurable from device tree data.
> 
> Signed-off-by: Timo Teräs <timo.teras@iki.fi>
> ---
> I'm not fully certain how the pullup data should be made configurable via OF.
> gpio-twl4030.c uses similar approach as this, but gpio-samsung.c makes the
> pullup configuration seems to be part of the custom data in gpio specifiers.

I think this should be specified for each individual GPIO. e.g.
> gpios = <&gpio-ctrl 0 GPIO_ACTIVE_HIGH GPIO_PULLUP>;

You don't know (yet) which pins might need a internal pull-up when specifying the mcp23s08 node itself.
You might override the controller node in your dts, but so you need to adjust 2 entries, one for the user and one for the pullup, rather than have all options at one place.

Best regards,
Alexander
-- 
Dipl.-Inf. Alexander Stein
SYS TEC electronic GmbH
alexander.stein@systec-electronic.com

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