Re: [RFC PATCH v11 net-next 02/10] dt-bindings: net: dsa: dt bindings for microchip lan937x

[Vladimir Oltean <olteanv@gmail.com>]

On Fri, Mar 25, 2022 at 10:23:33PM +0530, Prasanna Vengateshan wrote:
> Documentation in .yaml format and updates to the MAINTAINERS
> Also 'make dt_binding_check' is passed.
> 
> RGMII internal delay values for the mac is retrieved from
> rx-internal-delay-ps & tx-internal-delay-ps as per the feedback from
> v3 patch series.
> https://lore.kernel.org/netdev/20210802121550.gqgbipqdvp5x76ii@skbuf/
> 
> It supports only the delay value of 0ns and 2ns.
> 
> Signed-off-by: Prasanna Vengateshan <prasanna.vengateshan@microchip.com>
> Reviewed-by: Rob Herring <robh@kernel.org>
> ---
>  .../bindings/net/dsa/microchip,lan937x.yaml   | 160 ++++++++++++++++++
>  MAINTAINERS                                   |   1 +
>  2 files changed, 161 insertions(+)
>  create mode 100644 Documentation/devicetree/bindings/net/dsa/microchip,lan937x.yaml
> 
> diff --git a/Documentation/devicetree/bindings/net/dsa/microchip,lan937x.yaml b/Documentation/devicetree/bindings/net/dsa/microchip,lan937x.yaml
> new file mode 100644
> index 000000000000..8974506d8f69
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/net/dsa/microchip,lan937x.yaml
> @@ -0,0 +1,160 @@
> +# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
> +%YAML 1.2
> +---
> +$id: http://devicetree.org/schemas/net/dsa/microchip,lan937x.yaml#
> +$schema: http://devicetree.org/meta-schemas/core.yaml#
> +
> +title: LAN937x Ethernet Switch Series Tree Bindings
> +
> +maintainers:
> +  - UNGLinuxDriver@microchip.com
> +
> +allOf:
> +  - $ref: dsa.yaml#
> +
> +properties:
> +  compatible:
> +    enum:
> +      - microchip,lan9370
> +      - microchip,lan9371
> +      - microchip,lan9372
> +      - microchip,lan9373
> +      - microchip,lan9374
> +
> +  reg:
> +    maxItems: 1
> +
> +  spi-max-frequency:
> +    maximum: 50000000
> +
> +  reset-gpios:
> +    description: Optional gpio specifier for a reset line
> +    maxItems: 1
> +
> +  mdio:
> +    $ref: /schemas/net/mdio.yaml#
> +    unevaluatedProperties: false
> +
> +  tx-internal-delay-ps:
> +    enum: [0, 2000]
> +    default: 0
> +
> +  rx-internal-delay-ps:
> +    enum: [0, 2000]
> +    default: 0

Why are "tx-internal-delay-ps" and "rx-internal-delay-ps" properties of
the switch node and not of individual port nodes?

> +
> +required:
> +  - compatible
> +  - reg
> +
> +unevaluatedProperties: false
> +
> +examples:
> +  - |
> +    #include <dt-bindings/gpio/gpio.h>
> +
> +    //Ethernet switch connected via spi to the host

Comment seems off, this node doesn't correspond to an Ethernet switch
but to the DSA master.

> +    ethernet {
> +      #address-cells = <1>;
> +      #size-cells = <0>;
> +
> +      fixed-link {
> +        speed = <1000>;
> +        full-duplex;
> +      };
> +    };
> +
> +    spi {
> +      #address-cells = <1>;
> +      #size-cells = <0>;
> +
> +      lan9374: switch@0 {
> +        compatible = "microchip,lan9374";
> +        reg = <0>;
> +
> +        spi-max-frequency = <44000000>;
> +
> +        ethernet-ports {
> +          #address-cells = <1>;
> +          #size-cells = <0>;

Some blank lines here and there to separate the nodes from the
properties and from each other would go a long way. Similarly,
properties don't need new lines between each other ("reg" and
"spi-max-frequency").

> +          port@0 {
> +            reg = <0>;
> +            label = "lan1";
> +            phy-mode = "internal";
> +            phy-handle = <&t1phy0>;
> +          };
> +          port@1 {
> +            reg = <1>;
> +            label = "lan2";
> +            phy-mode = "internal";
> +            phy-handle = <&t1phy1>;
> +          };
> +          port@2 {
> +            reg = <2>;
> +            label = "lan4";
> +            phy-mode = "internal";
> +            phy-handle = <&t1phy2>;
> +          };
> +          port@3 {
> +            reg = <3>;
> +            label = "lan6";
> +            phy-mode = "internal";
> +            phy-handle = <&t1phy3>;
> +          };
> +          port@4 {
> +            reg = <4>;
> +            phy-mode = "rgmii";
> +            ethernet = <&ethernet>;

shouldn't the "ethernet" node have a label for this to work? Does this
example compile?

> +            fixed-link {
> +              speed = <1000>;
> +              full-duplex;
> +            };
> +          };
> +          port@5 {
> +            reg = <5>;
> +            label = "lan7";
> +            phy-mode = "rgmii";
> +            fixed-link {
> +              speed = <1000>;
> +              full-duplex;
> +            };
> +          };
> +          port@6 {
> +            reg = <6>;
> +            label = "lan5";
> +            phy-mode = "internal";
> +            phy-handle = <&t1phy6>;
> +          };
> +          port@7 {
> +            reg = <7>;
> +            label = "lan3";
> +            phy-mode = "internal";
> +            phy-handle = <&t1phy7>;
> +          };
> +        };
> +
> +        mdio {
> +          #address-cells = <1>;
> +          #size-cells = <0>;
> +
> +          t1phy0: ethernet-phy@0{
> +            reg = <0x0>;
> +          };
> +          t1phy1: ethernet-phy@1{
> +            reg = <0x1>;
> +          };
> +          t1phy2: ethernet-phy@2{
> +            reg = <0x2>;
> +          };
> +          t1phy3: ethernet-phy@3{
> +            reg = <0x3>;
> +          };
> +          t1phy6: ethernet-phy@6{
> +            reg = <0x6>;
> +          };
> +          t1phy7: ethernet-phy@7{
> +            reg = <0x7>;
> +          };
> +        };
> +      };
> +    };
> diff --git a/MAINTAINERS b/MAINTAINERS
> index 91c04cb65247..373eaee3c8b9 100644
> --- a/MAINTAINERS
> +++ b/MAINTAINERS
> @@ -12719,6 +12719,7 @@ M:	UNGLinuxDriver@microchip.com
>  L:	netdev@vger.kernel.org
>  S:	Maintained
>  F:	Documentation/devicetree/bindings/net/dsa/microchip,ksz.yaml
> +F:	Documentation/devicetree/bindings/net/dsa/microchip,lan937x.yaml
>  F:	drivers/net/dsa/microchip/*
>  F:	include/linux/platform_data/microchip-ksz.h
>  F:	net/dsa/tag_ksz.c
> -- 
> 2.30.2
>