Re: [PATCH 08/21] dt-bindings: mfd: x-powers: add AC200

Andrew Lunn <[email protected]> Tue, 4 Aug 2026 04:14:31 +0200
Newsgroups dev.linux.lists.linux-sunxi,dev.linux.lists.mfd,org.infradead.lists.linux-arm-kernel,org.infradead.lists.linux-rockchip,org.kernel.vger.linux-devicetree,org.kernel.vger.linux-kernel,org.kernel.vger.netdev
Message-ID <[email protected]>
On Tue, Aug 04, 2026 at 12:51:57AM +0800, Chen-Yu Tsai wrote:
> On Tue, Aug 4, 2026 at 12:45 AM James Hilliard
> <[email protected]> wrote:
> >
> > On Mon, Aug 3, 2026 at 7:18 AM Andrew Lunn <[email protected]> wrote:
> > >
> > > > +            ethernet-phy-control {
> > > > +                compatible = "x-powers,ac200-ephy-ctl";
> > > > +                nvmem-cells = <&ephy_calibration>;
> > > > +                nvmem-cell-names = "calibration";
> > > > +                phy-mode = "rmii";
> > > > +            };
> > >
> > > What do you mean by an ethernet PHY control?
> > >
> > > I assume this is not an actual Ethernet PHY, but some control logic
> > > around it? Where is the ethernet PHY itself?
> >
> > Correct, this is not the Ethernet PHY itself. It is the package-specific
> > sideband control block that must be configured before the normal Clause 22
> > PHY registers become usable. For AC200, this control block is accessed
> > through the parent AC200 I2C regmap. For AC300, the equivalent control block
> > is accessed through a separate non-PHY Clause 22 address.
> 
> Basically, all the PHY behavior that is normally configured using strapping
> pins on a discrete PHY is done over this I2C channel.

To me this should still be part of the PHY driver, not a separate
driver. The driver drives the hardware, it should drive all of it, all
in one place.

	Andrew