Re: [PATCH net-next 1/8] dt-bindings: net: dsa: dt bindings for microchip lan937x

From: Vladimir Oltean
Date: Fri Jan 29 2021 - 21:25:06 EST


On Thu, Jan 28, 2021 at 12:11:05PM +0530, Prasanna Vengateshan wrote:
> + spi-max-frequency:
> + maximum: 50000000

And it actually works at 50 MHz? Cool.

> +
> + reset-gpios:
> + description: Optional gpio specifier for a reset line
> + maxItems: 1
> +
> +required:
> + - compatible
> + - reg
> +
> +unevaluatedProperties: false
> +
> +examples:
> + - |
> + #include <dt-bindings/gpio/gpio.h>
> +
> + //Ethernet switch connected via spi to the host, CPU port wired to eth1
> + eth1 {

So if you do bother to add the DSA master in the example, can this be
&eth1 so that we could associate with the phandle below?

> + #address-cells = <1>;
> + #size-cells = <0>;
> +
> + fixed-link {
> + speed = <1000>;
> + full-duplex;
> + };
> + };
> +
> + spi1 {

Is this a label or a node name? spi1 or spi@1?

> + #address-cells = <1>;
> + #size-cells = <0>;
> + pinctrl-0 = <&pinctrl_spi_ksz>;
> + cs-gpios = <0>, <0>, <0>, <&pioC 28 0>;
> + id = <1>;

I know this is the SPI controller and thus mostly irrelevant, but what
is "id = <1>"?

> +
> + lan9374: switch@0 {
> + compatible = "microchip,lan9374";
> + reg = <0>;
> +
> + spi-max-frequency = <44000000>;
> +
> + ethernet-ports {
> + #address-cells = <1>;
> + #size-cells = <0>;
> + port@0 {
> + reg = <0>;
> + label = "lan1";
> + };
> + port@1 {
> + reg = <1>;
> + label = "lan2";
> + };
> + port@2 {
> + reg = <7>;

reg should match node index (port@2), here and everywhere below. As for
the net device labels, I'm not sure if the mismatch is deliberate there.

> + label = "lan3";
> + };
> + port@3 {
> + reg = <2>;
> + label = "lan4";
> + };
> + port@4 {
> + reg = <6>;
> + label = "lan5";
> + };
> + port@5 {
> + reg = <3>;
> + label = "lan6";
> + };
> + port@6 {
> + reg = <4>;
> + label = "cpu";

label for CPU port is not needed/used.

> + ethernet = <&eth1>;
> + fixed-link {
> + speed = <1000>;
> + full-duplex;
> + };
> + };
> + port@7 {
> + reg = <5>;
> + label = "lan7";
> + fixed-link {
> + speed = <1000>;
> + full-duplex;
> + };
> + };
> + };
> + };
> + };