Re: [PATCH net-next v2 5/8] dt-bindings: net: x-powers: add AC300 EPHY control

[James Hilliard]

On Wed, Aug 5, 2026 at 8:17 AM Rob Herring <robh@xxxxxxxxxx> wrote:
>
> On Tue, Aug 04, 2026 at 08:27:03PM -0600, James Hilliard wrote:
> > The AC300 exposes its Fast Ethernet PHY control registers through a
> > separate non-PHY Clause 22 address. The manual defines that address as
> > the link PHY address plus 16, giving control addresses 16 through 23 and
> > link addresses 0 through 7.
>
> That's not a separate device, but just a second address range. You
> should make 'reg' have 2 entries.

I tried a different approach in my v3 using ethernet-phy-package to
instead of ctrl drivers with the AC300 control address specified by the
ethernet-phy-package register(internal it's doing a + 16 to get align
with existing conventions).

>
> >
> > Describe the control endpoint, its required VCC1 supply, its 24, 25 or
> > 27 MHz input clock and its SoC SID calibration cell. The actual PHY
> > remains a separate ethernet-phy node and supplies the MAC-selected
> > interface mode at runtime.
> >
> > Signed-off-by: James Hilliard <james.hilliard1@xxxxxxxxx>
> > ---
> >  .../bindings/net/x-powers,ac300-ephy-ctl.yaml      | 70 ++++++++++++++++++++++
> >  1 file changed, 70 insertions(+)
> >
> > diff --git a/Documentation/devicetree/bindings/net/x-powers,ac300-ephy-ctl.yaml b/Documentation/devicetree/bindings/net/x-powers,ac300-ephy-ctl.yaml
> > new file mode 100644
> > index 000000000000..8a616ff3e89f
> > --- /dev/null
> > +++ b/Documentation/devicetree/bindings/net/x-powers,ac300-ephy-ctl.yaml
> > @@ -0,0 +1,70 @@
> > +# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
> > +%YAML 1.2
> > +---
> > +$id: http://devicetree.org/schemas/net/x-powers,ac300-ephy-ctl.yaml#
> > +$schema: http://devicetree.org/meta-schemas/core.yaml#
> > +
> > +title: X-Powers AC300 Ethernet PHY control interface
> > +
> > +maintainers:
> > +  - James Hilliard <james.hilliard1@xxxxxxxxx>
> > +
> > +description:
> > +  The AC300 Fast Ethernet PHY has a separate control interface accessed as a
> > +  non-PHY Clause 22 device. Its address is 16 plus the address of the link PHY.
> > +
> > +properties:
> > +  compatible:
> > +    const: x-powers,ac300-ephy-ctl
> > +
> > +  reg:
> > +    minimum: 16
> > +    maximum: 23
> > +
> > +  clocks:
> > +    maxItems: 1
> > +    description:
> > +      AC300 input clock. Its configured rate must be 24, 25, or 27 MHz and
> > +      determines the corresponding EPHY_CLK_SEL value.
> > +
> > +  vcc1-supply:
> > +    description:
> > +      3.3 V supply for the AC300 I/O, bandgap, Ethernet PHY analog front end,
> > +      and internal digital LDO
>
> Sounds like this supply and clock would need to be enabled before
> accessing the "link PHY address"? If so, then 2 nodes is really a
> problem.

I think having the link node depend on the ctrl node was preventing
issues there AFAIU. My v3 works differently though.

>
> Rob