Re: [PATCH v2 2/4] dt-bindings: pinctrl: qcom,tlmm-common: document i2c pull property

[Neil Armstrong]

Hi Linus,

On 24/11/2022 14:11, Linus Walleij wrote:
> On Wed, Nov 23, 2022 at 4:20 PM Abel Vesa <abel.vesa@xxxxxxxxxx> wrote:
>
> > From: Neil Armstrong <neil.armstrong@xxxxxxxxxx>
> >
> > Document the new i2c_pull property introduced for SM8550 setting
> > an I2C specific pull mode on I2C able pins.
> >
> > Signed-off-by: Neil Armstrong <neil.armstrong@xxxxxxxxxx>
> > Signed-off-by: Abel Vesa <abel.vesa@xxxxxxxxxx>
> (...)
> > +      qcom,i2c-pull:
> > +        type: boolean
> > +        description: enable bias pull feature designed for I2C on pin
>
> But what is this?
>
> I2C buses are usually just plain old bias-high-impedance, high-z
> or open drain, wire-or or whatever you want to call it.
>
> But now there is some special i2c mode, huh?
>
> The description is pretty much "it is what it is"... can we have
> some explanation about what this means electrically speaking
> and why you cannot use bias-high-impedance?

I'll try to get some more info, but so far I only found what I wrote in the bindings.

Neil

> Yours,
> Linus Walleij