[PATCH] pinctrl: establish pull-up/pull-down terminology

Linus Walleij linus.walleij at linaro.org
Mon Jun 24 08:24:12 EDT 2013


On Sat, Jun 22, 2013 at 1:39 AM, Heiko Stübner <heiko at sntech.de> wrote:
> Am Samstag, 22. Juni 2013, 01:30:18 schrieb Laurent Pinchart:
>> [Stephen]
>> > IIRC the idea of the PULL_PIN_DEFAULT was to avoid having to specify
>> > UP/DOWN for each pin/group, but could just say "default", which would
>> > then reduce the number of pinctrl mapping table entries or pinctrl DT
>> > property entries.
>>
>> I may be mistaken, but I've understood the PULL_PIN_DEFAULT option as a way
>> to select the default bias configuration when the default value is
>> hardware- controlled, not as a pure software option.
>
> Yep that was the original intent ... to handle hardware that hides the
> complete logic from the software and you only get to turn it on or off, while
> the direction and other params are determined internally for example by the
> pin function.

Heiko, can you send a documentation patch to clarify this so we
don't get any misunderstandings?

Maybe it'd be useful for software purposes as well, but let's save
that for when it gets used like that.

Yours,
Linus Walleij



More information about the linux-arm-kernel mailing list