Re: [PATCH v2 3/5] arm64: dts: meson: g12a: add mdio multiplexer
From: Andrew Lunn
Date: Mon May 20 2019 - 15:08:08 EST
> > + int_mdio: mdio@1 {
> > + reg = <1>;
> > + #address-cells = <1>;
> > + #size-cells = <0>;
> > +
> > + internal_ephy: ethernet_phy@8 {
> > + compatible = "ethernet-phy-id0180.3301",
> > + "ethernet-phy-ieee802.3-c22";
> Based on your comment on v1 of this patch [0] the Ethernet PHY ID is
> defined by this "mdio-multiplexer" (write arbitrary value to a
> register then that's the PHY ID which will show up on the bus)
> I'm fine with explicitly listing the ID which the PHY driver binds to
> because I don't know a better way.
Does reading the ID registers give the correct ID, once you have poked
registers in the mdio-multiplexer? If so, you don't need this
compatible string.
If the read is giving the wrong ID, then yes, you do want this. But
then please add a comment in the DT blob. This is very unusual, so
should have some explanation why it is needed.
Thanks
Andrew