Re: [PATCH v13 1/3] dt-bindings: i2c: Add CP2112 HID USB to SMBus Bridge

From: Andy Shevchenko

Date: Wed Jan 28 2026 - 11:17:07 EST


On Wed, Jan 28, 2026 at 03:06:58PM +0000, Conor Dooley wrote:
> On Wed, Jan 28, 2026 at 02:49:39PM +0200, Andy Shevchenko wrote:
> > On Wed, Jan 28, 2026 at 11:35:25AM +0100, Krzysztof Kozlowski wrote:
> > > On Tue, Jan 27, 2026 at 10:02:17AM -0600, Danny Kaehn wrote:

...

> > > That's actually rule communicated many times, also documented in writing
> > > bindings and in recent talks.
> >
> > Does DT represents HW in this case? Shouldn't I²C controller be the same node?
> > Why not? This is inconsistent for the device that is multi-functional. And from
> > my understanding the firmware description (DT, ACPI, you-name-it) must follow
> > the HW. I don't see how it's done in this case.
>
> The i2c controller should probably be in the same node too, unless it
> would cause conflicts between function (e.g. inability to figure out if
> a child is a hog or a i2c device). I would like a rationale provided for
> why the i2c controller is in a subnode.

I can expect a disaster with such a scheme, splitting multi-functional device
to the subdevices (children) sounds to me like the best approach. With this,
one may have the same (globally named) property to be different on subdevices.

But I will hold my breath to see the outcome of this discussion.

--
With Best Regards,
Andy Shevchenko