Re: [RFC PATCH 0/3] i2c: Introduce i2c bus extensions

Luca Ceresoli
2025-03-20T16:32:00Z

Hi Wolfram,

On Thu, 20 Mar 2025 13:49:53 +0100
Wolfram Sang <wsa+renesas@sang-engineering.com> wrote:

> Hi Herve,
>
> > The related big picture has been already presented in
> > - the 'Add support for GE SUNH hot-pluggable connector' series [0]
> > - the 'Runtime hotplug on non-discoverable busses with device tree
> > overlays' talk at Linux Plumbers Conference 2024 [1].
>
> Any outcome of the Plumbers meetup? Was this "double-link" solution
> agreed on or so?

The i2c-parent was proposed by Rob [0]. The need for the double link
is what you, Hervé and I had agreed during our discussion after LPC,
based on having realized that the forward link is insufficient for some
cases (see "Second case" in the cover letter).

> I mean the code is the easy part here, but I would like
> to have an agreed approach for handling all kinds of non-probable
> busses. I really don't want an island solution for I2C. So, the key
> question here is what do DT maintainers think?
>
> You sent code without bindings, but I'd think the other way around would
> be better for the discussion.

[0] https://lore.kernel.org/lkml/20240510163625.GA336987-robh@kernel.org/

Luca

--
Luca Ceresoli, Bootlin
Embedded Linux and Kernel engineering