Re: [PATCH v1 1/8] dt-bindings: pinctrl: Add thead,th1520-pinctrl bindings

From: Linus Walleij
Date: Wed Dec 20 2023 - 14:25:31 EST


On Sat, Dec 16, 2023 at 2:57 PM Emil Renner Berthing
<emil.renner.berthing@xxxxxxxxxxxxx> wrote:

> > > + thead,strong-pull-up:
> > > + oneOf:
> > > + - type: boolean
> > > + - $ref: /schemas/types.yaml#/definitions/uint32
> > > + enum: [ 0, 2100 ]
> > > + description: Enable or disable strong 2.1kOhm pull-up.
> >
> > bias-pull-up can already specify the strength in Ohms.
>
> The strong pull up is a separate bit that can be enabled independently from the
> regular pull-up/down, so in theory you could enable both the regular pull-up
> and the strong pull-up at the same time, or even the regular poll-down and the
> strong pull-up which is probably not advised.

bias-pull-up; <- Just regular pulling up the ordinary
bias-pull-up = <100>; <- Same thing if the ordinary is 100 Ohm (figure out what
resistance it actually is....)
bias-pull-up = <21000000>; <- strong pull up
bias-pull-up = <21000100>; <- both at the same time

> So the idea here was just to make sure that you can do eg.
>
> thead,strong-pull-up = <0>;
>
> to make sure the bit is cleared.

No use bias-disable; for this.

Yours,
Linus Walleij