Re: [PATCH net-next 07/15] mfd: core: add ability for cells to probe on a custom parent OF node

Vladimir Oltean
2025-11-20T15:36:30Z

On Thu, Nov 20, 2025 at 02:41:36PM +0000, Lee Jones wrote:
> On Tue, 18 Nov 2025, Vladimir Oltean wrote:
>
> > I would like the "nxp,sja1110a" driver, in the configuration below, to
> > be able to probe the drivers for "nxp,sja1110-base-t1-mdio" and for
> > "nxp,sja1110-base-tx-mdio" via mfd_add_devices():
> >
> > ethernet-switch@0 {
> > compatible = "nxp,sja1110a";
> >
> > mdios {
> > mdio@0 {
> > compatible = "nxp,sja1110-base-t1-mdio";
> > };
> >
> > mdio@1 {
> > compatible = "nxp,sja1110-base-tx-mdio";
> > };
> > };
> > };
>
> This device is not an MFD.
>
> Please find a different way to instantiate these network drivers.

Ok.. but what is an MFD? I'm seriously interested in a definition.

One data point: the VSC7512 (driver in drivers/mfd/ocelot-spi.c,
bindings in Documentation/devicetree/bindings/mfd/mscc,ocelot.yaml) is
almost the same class of hardware (except the embedded Cortex-M7 in
SJA1110 can't run Linux, and the CPU in VSC7512 can). It instantiates
MDIO bus children, like this patch proposes too, except it works with a
different device tree hierarchy which I need to adapt to, without breaking.