Aw: Re: Re: [RFC v1] dt-bindings: net: dsa: convert binding for mediatek switches

[Frank Wunderlich <frank-w@public-files.de>]

Hi,

> Gesendet: Dienstag, 03. Mai 2022 um 16:40 Uhr
> Von: "Krzysztof Kozlowski" <krzysztof.kozlowski@linaro.org>
> Betreff: Re: Aw: Re: [RFC v1] dt-bindings: net: dsa: convert binding for mediatek switches
>
> On 03/05/2022 16:10, Frank Wunderlich wrote:
> > Hi,
> >
> > thank you for first review.
> >
> >> Gesendet: Dienstag, 03. Mai 2022 um 14:05 Uhr
> >> Von: "Krzysztof Kozlowski" <krzysztof.kozlowski@linaro.org>
> >> Betreff: Re: [RFC v1] dt-bindings: net: dsa: convert binding for mediatek switches
> >>
> >> On 02/05/2022 17:32, Frank Wunderlich wrote:
> >>> From: Frank Wunderlich <frank-w@public-files.de>
> >>>
> >>> Convert txt binding to yaml binding for Mediatek switches.
> >>>
> >>> Signed-off-by: Frank Wunderlich <frank-w@public-files.de>
> >>> ---
> >>>  .../devicetree/bindings/net/dsa/mediatek.yaml | 435 ++++++++++++++++++
> >>>  .../devicetree/bindings/net/dsa/mt7530.txt    | 327 -------------
> >>>  2 files changed, 435 insertions(+), 327 deletions(-)
> >>>  create mode 100644 Documentation/devicetree/bindings/net/dsa/mediatek.yaml
> >>>  delete mode 100644 Documentation/devicetree/bindings/net/dsa/mt7530.txt
> >>>
> >>> diff --git a/Documentation/devicetree/bindings/net/dsa/mediatek.yaml b/Documentation/devicetree/bindings/net/dsa/mediatek.yaml
> >>> new file mode 100644
> >>> index 000000000000..c1724809d34e
> >>> --- /dev/null
> >>> +++ b/Documentation/devicetree/bindings/net/dsa/mediatek.yaml
> >>
> >> Specific name please, so previous (with vendor prefix) was better:
> >> mediatek,mt7530.yaml
> >
> > ok, named it mediatek only because mt7530 is only one possible chip and driver handles 3 different "variants".
> >
> >>> @@ -0,0 +1,435 @@
> >>> +# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
> >>
> >> You should CC previous contributors and get their acks on this. You
> >> copied here a lot of description.
> >
> > added 3 Persons that made commits to txt before to let them know about this change
> >
> > and yes, i tried to define at least the phy-mode requirement as yaml-depency, but failed because i cannot match
> > compatible in subnode.
>
> I don't remember such syntax.
>
> (...)

have not posted this version as it was failing in dtbs_check, this was how i tried:

https://github.com/frank-w/BPI-R2-4.14/blob/8f2033eb6fcae273580263c3f0b31f0d48821740/Documentation/devicetree/bindings/net/dsa/mediatek.yaml#L177


> >>> if defined, indicates that either MT7530 is the part
> >>> +      on multi-chip module belong to MT7623A has or the remotely standalone
> >>> +      chip as the function MT7623N reference board provided for.
> >>> +
> >>> +  reset-gpios:
> >>> +    description: |
> >>> +      Should be a gpio specifier for a reset line.
> >>> +    maxItems: 1
> >>> +
> >>> +  reset-names:
> >>> +    description: |
> >>> +      Should be set to "mcm".
> >>> +    const: mcm
> >>> +
> >>> +  resets:
> >>> +    description: |
> >>> +      Phandle pointing to the system reset controller with
> >>> +      line index for the ethsys.
> >>> +    maxItems: 1
> >>> +
> >>> +required:
> >>> +  - compatible
> >>> +  - reg
> >>
> >> What about address/size cells?
> >
> > you're right even if they are const to a value they need to be set
> >
> >>> +
> >>> +allOf:
> >>> +  - $ref: "dsa.yaml#"
> >>> +  - if:
> >>> +      required:
> >>> +        - mediatek,mcm
> >>
> >> Original bindings had this reversed.
> >
> > i know, but i think it is better readable and i will drop the else-part later.
> > Driver supports optional reset ("mediatek,mcm" unset and without reset-gpios)
> > as this is needed if there is a shared reset-line for gmac and switch like on R2 Pro.
> >
> > i left this as separate commit to be posted later to have a nearly 1:1 conversion here.
>
> Ah, I missed that actually your syntax is better. No need to
> reverse/negate and the changes do not have to be strict 1:1.

yes, but a conversion implies same meaning, so changing things later ;)

> >>> +    then:
> >>> +      required:
> >>> +        - resets
> >>> +        - reset-names
> >>> +    else:
> >>> +      required:
> >>> +        - reset-gpios
> >>> +
> >>> +  - if:
> >>> +      required:
> >>> +        - interrupt-controller
> >>> +    then:
> >>> +      required:
> >>> +        - "#interrupt-cells"
> >>
> >> This should come from dt schema already...
> >
> > so i should drop (complete block for interrupt controller)?
>
> The interrupts you need. What I mean, you can skip requirement of cells.

ok, i drop only the #interrupt-cells

> >>> +        - interrupts
> >>> +
> >>> +  - if:
> >>> +      properties:
> >>> +        compatible:
> >>> +          items:
> >>> +            - const: mediatek,mt7530
> >>> +    then:
> >>> +      required:
> >>> +        - core-supply
> >>> +        - io-supply
> >>> +
> >>> +
> >>> +patternProperties:
> >>> +  "^ports$":
> >>
> >> It''s not a pattern, so put it under properties, like regular property.
> >
> > can i then make the subnodes match? so the full block will move above required between "mediatek,mcm" and "reset-gpios"
>
> Yes, subnodes stay with patternProperties.
>
> >
> >   ports:
> >     type: object
> >
> >     patternProperties:
> >       "^port@[0-9]+$":
> >         type: object
> >         description: Ethernet switch ports
> >
> >         properties:
> >           reg:
> >             description: |
> >               Port address described must be 5 or 6 for CPU port and from 0 to 5 for user ports.
> >
> >         unevaluatedProperties: false
> >
> >         allOf:
> >           - $ref: dsa-port.yaml#
> >           - if:
> > ....
> >
> > basicly this "ports"-property should be required too, right?
>
> Previous binding did not enforce it, I think, but it is reasonable to
> require ports.

basicly it is required in dsa.yaml, so it will be redundant here

https://elixir.bootlin.com/linux/v5.18-rc5/source/Documentation/devicetree/bindings/net/dsa/dsa.yaml#L55

this defines it as pattern "^(ethernet-)?ports$" and should be processed by dsa-core. so maybe changing it to same pattern instead of moving up as normal property?

> >>> +    type: object
> >>> +
> >>> +    patternProperties:
> >>> +      "^port@[0-9]+$":
> >>> +        type: object
> >>> +        description: Ethernet switch ports
> >>> +
> >>> +        $ref: dsa-port.yaml#
> >>
> >> This should go to allOf below.
> >
> > see above
> >
> >>> +
> >>> +        properties:
> >>> +          reg:
> >>> +            description: |
> >>> +              Port address described must be 6 for CPU port and from 0 to 5 for user ports.
> >>> +
> >>> +        unevaluatedProperties: false
> >>> +
> >>> +        allOf:
> >>> +          - if:
> >>> +              properties:
> >>> +                label:
> >>> +                  items:
> >>> +                    - const: cpu
> >>> +            then:
> >>> +              required:
> >>> +                - reg
> >>> +                - phy-mode
> >>> +
> >>> +unevaluatedProperties: false
> >>> +
> >>> +examples:
> >>> +  - |
> >>> +    mdio0 {
> >>
> >> Just mdio
> >
> > ok
> >
> >>> +        #address-cells = <1>;
> >>> +        #size-cells = <0>;
> >>> +        switch@0 {
> >>> +            compatible = "mediatek,mt7530";
> >>> +            #address-cells = <1>;
> >>> +            #size-cells = <0>;
> >>> +            reg = <0>;
> >>> +
> >>> +            core-supply = <&mt6323_vpa_reg>;
> >>> +            io-supply = <&mt6323_vemc3v3_reg>;
> >>> +            reset-gpios = <&pio 33 0>;
> >>
> >> Use GPIO flag define/constant.
> >
> > this example seems to be taken from bpi-r2 (i had taken it from the txt). In dts for this board there are no
> > constants too.
> >
> > i guess
> > include/dt-bindings/gpio/gpio.h:14:#define GPIO_ACTIVE_HIGH 0
> >
> > for 33 there seem no constant..all other references to pio node are with numbers too and there seem no binding
> > header defining the gpio pins (only functions in include/dt-bindings/pinctrl/mt7623-pinfunc.h)
>
> ok, then my comment

you mean adding a comment to the example that GPIO-flags/constants should be used instead of magic numbers?

> Best regards,
> Krzysztof

this is how it looks like without the port-property-change:
https://github.com/frank-w/BPI-R2-4.14/blob/5.18-mt7531-mainline/Documentation/devicetree/bindings/net/dsa/mediatek,mt7530.yaml

regards Frank