[PATCH 1/2] pinctrl: add function to parse generic pinconfig properties from a dt node
linus.walleij at linaro.org
Sun Jun 16 06:39:44 EDT 2013
On Fri, Jun 14, 2013 at 4:52 PM, Laurent Pinchart
<laurent.pinchart at ideasonboard.com> wrote:
> On Friday 14 June 2013 11:18:22 Heiko Stübner wrote:
>> > What's the expected way to disable pull-ups in DT ? Should it be
>> > 'bias-pull-up = <0>;' or 'bias-disable;' ?
>> According to the kernedoc I think both are valid and should be handled.
>> Using bias-disable is more descriptive but would also include disabling a
>> "high-impedance" or "bus-hold" bias (if supported by the hardware).
> OK. I still fail to see how the various bias options are supposed to interract
> together, but I don't think I'll get an answer on that.
>> Personally, for my rockchip stuff I go with using the
>> "bias-pull-pin-default" <-> "bias-disable".
I think bias-pull-up = <0>; should actually mean "connect the
pin to VDD" and bias-pull-down = <0>; should mean "ground
This makes a lot of sense from the electronics side of things,
let's not create a terminology that appeals to programmers,
such that "zero always means boolean disable", because we're
dealing with electronics here.
More information about the linux-arm-kernel