Re: [PATCH 2/9] dt-bindings: i2c: qcom-cci: add description of a vbus-supply property

[Mark Brown <broonie@kernel.org>]

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On Mon, Feb 07, 2022 at 08:31:30PM +0200, Vladimir Zapolskiy wrote:
> On 2/7/22 4:39 PM, Mark Brown wrote:

> > The bindings are ABI, it doesn't seem like a good idea to add new ABI as
> > a temporary bodge.

> The bindings are supposed to describe hardware, thus it's natural to extend
> them, I believe there is a trilemma in this particular case:
> 1) add optional vbus-supply property to all I2C master controllers or I2C
>    busses in case of multiple I2C busses managed by a single controller,
> 2) add optional vbus-supply property to all I2C slave devices,

If you add a named supply to all I2C controllers or devices then if any
of them have an actual vbus supply there will be a namespace collision.

> 3) ignore peculiarities of particular (multiple in fact) PCB designs and
>    a necessity of adding a regulator finely described as a pull-up for I2C
>    bus lines.

There's also the option of representing this as a separate thing on or
part of the bus.

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