Re: [PATCH net-next v4 4/8] dt-bindings: mfd: Add SoC-e SWIP parent

[Vasilij Strassheim <v.strassheim@linutronix.de>]

On Fri, 2026-11-06 at 12:13 +0100, Krzysztof Kozlowski wrote:
> On Thu, Nov 05, 2026 at 03:16:48PM +0100, Vasilij Strassheim wrote:
> > Add a binding for the SoC-e SWIP multifunction FPGA IP core.
> > 
> > Describe the shared MMIO address space and address translation for
> > the required Ethernet switch child and the optional integrated MDIO
> > controller and MMIO-controlled MDIO multiplexer.
> > 
> > Signed-off-by: Vasilij Strassheim <v.strassheim@linutronix.de>
> > ---
> >  .../devicetree/bindings/mfd/soce,swip.yaml         | 137 +++++++++++++++++++++
> >  1 file changed, 137 insertions(+)
> > 
> > diff --git a/Documentation/devicetree/bindings/mfd/soce,swip.yaml b/Documentation/devicetree/bindings/mfd/soce,swip.yaml
> > new file mode 100644
> > index 000000000000..625be299e262
> > --- /dev/null
> > +++ b/Documentation/devicetree/bindings/mfd/soce,swip.yaml
> > @@ -0,0 +1,137 @@
> > +# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
> > +%YAML 1.2
> > +---
> > +$id: http://devicetree.org/schemas/mfd/soce,swip.yaml#
> > +$schema: http://devicetree.org/meta-schemas/core.yaml#
> > +
> > +title: SoC-e SWIP multifunction Ethernet switch FPGA IP core
> > +
> > +maintainers:
> > +  - Vasilij Strassheim <v.strassheim@linutronix.de>
> > +
> > +description:
> > +  SoC-e Switch IP (SWIP) cores integrate Ethernet switching logic, an
> > +  MDIO controller, and an MDIO bus multiplexer in one memory-mapped device.
> > +  The MDIO bus multiplexer is wired to the integrated MDIO controller.
> > +
> > +properties:
> > +  compatible:
> > +    const: soce,swip
> > +
> > +  reg:
> > +    maxItems: 1
> > +
> > +  '#address-cells':
> > +    const: 1
> > +
> > +  '#size-cells':
> > +    const: 1
> > +
> > +  ranges: true
> > +
> > +  mdio@204:
> > +    $ref: /schemas/net/soce,swip-mdio.yaml#
> > +    unevaluatedProperties: false
> > +
> > +  mdio-mux@202:
> > +    $ref: /schemas/net/mdio-mux-mmioreg.yaml#
> > +    unevaluatedProperties: false
> > +
> > +  ethernet-switch:
> 
> Why are you mixing children with and without bus addresses? This is
> discouraged and shows that device is not correctly represented, e.g. if
> the ethernet-switch does not have resources, then THIS device is the
> ethernet switch.
> 

There is no hardware reason for leaving the switch child unaddressed.
Just an error that occurred while converting the binding to the MFD
model.
I will describe the switch function as an ethernet-switch@0 child node
with a reg property for it's register resources, like the ocelot MFD
binding.

> > +    $ref: /schemas/net/dsa/soce,swip-switch.yaml#
> > +    unevaluatedProperties: false
> > +
> > +required:
> > +  - compatible
> > +  - reg
> > +  - '#address-cells'
> > +  - '#size-cells'
> > +  - ranges
> > +  - ethernet-switch
> > +
> > +dependentRequired:
> > +  mdio-mux@202:
> > +    - mdio@204
> > +
> > +additionalProperties: false
> > +
> > +examples:
> > +  - |
> > +    ethernet-switch@80020000 {
> > +        compatible = "soce,swip";
> > +        reg = <0x80020000 0x10000>;
> > +        #address-cells = <1>;
> > +        #size-cells = <1>;
> > +        ranges = <0x0 0x80020000 0x10000>;
> > +
> > +        mdio_parent: mdio@204 {
> > +            compatible = "soce,swip-mdio";
> > +            reg = <0x204 0xc>, <0x200 0x2>;
> > +            reg-names = "data", "control";
> > +            #address-cells = <1>;
> > +            #size-cells = <0>;
> > +        };
> > +
> > +        mdio-mux@202 {
> 
> Nodes are ordered by unit address.

I will fix that.
Sashiko mentioned scripts/dtc/dt-check-style to find this. I wasn't
aware of this before and will use it more often in the future
additionally to dt_binding_check.

> 
> Best regards,
> Krzysztof
> 

Thanks,
Vasilij