Re: [PATCH V2 1/3] Documentation: devicetree: add multiple cpu port DSA binding

[Florian Fainelli <f.fainelli@gmail.com>]

On 05/30/2017 03:44 AM, John Crispin wrote:
> Extend the DSA binding documentation, adding the new property required
> when there is more than one CPU port attached to the switch.
> 
> Cc: Rob Herring <robh+dt@kernel.org>
> Cc: devicetree@vger.kernel.org
> Signed-off-by: John Crispin <john@phrozen.org>
> ---
>  Documentation/devicetree/bindings/net/dsa/dsa.txt | 61 ++++++++++++++++++++++-
>  1 file changed, 60 insertions(+), 1 deletion(-)
> 
> diff --git a/Documentation/devicetree/bindings/net/dsa/dsa.txt b/Documentation/devicetree/bindings/net/dsa/dsa.txt
> index cfe8f64eca4f..c164eb38ccc5 100644
> --- a/Documentation/devicetree/bindings/net/dsa/dsa.txt
> +++ b/Documentation/devicetree/bindings/net/dsa/dsa.txt
> @@ -55,6 +55,11 @@ A user port has the following optional property:
>  - label			: Describes the label associated with this port, which
>                            will become the netdev name.
>  
> +- cpu			: Option for non "cpu"/"dsa" ports. A phandle to a
> +			  "cpu" port, which will be used for passing packets
> +			  from this port to the host. If not present, the first
> +			  "cpu" port will be used.

So this option essentially allow us to "partition" the switch between
vectors of ports and their upstream/CPU port.

While using Device Tree is an obvious choice for making the initial
partitioning, it seems like we are missing a configuration mechanism
whereby we can properly assign ports to a specific upstream CPU port.

Let's move the actual discussion into patch 2 in order not to pollute
the DT maintainers' inbox.

> +
>  Port child nodes may also contain the following optional standardised
>  properties, described in binding documents:
>  
> @@ -71,7 +76,7 @@ properties, described in binding documents:
>  			  Documentation/devicetree/bindings/net/fixed-link.txt
>  			  for details.
>  
> -Example
> +Examples
>  
>  The following example shows three switches on three MDIO busses,
>  linked into one DSA cluster.
> @@ -264,6 +269,60 @@ linked into one DSA cluster.
>  	};
>  };
>  
> +The following example shows a switch that has two cpu ports each connecting
> +to a different MAC.
> +
> +&mdio0 {
> +	switch@0 {
> +		compatible = "mediatek,mt7530";
> +		#address-cells = <1>;
> +		#size-cells = <0>;
> +		reg = <0>;
> +
> +		ports {
> +			#address-cells = <1>;
> +			#size-cells = <0>;
> +			port@0 {
> +				reg = <0>;
> +				label = "lan0";
> +				cpu = <&cpu_port1>;
> +			};
> +
> +			port@1 {
> +				reg = <1>;
> +				label = "lan1";
> +				cpu = <&cpu_port1>;
> +			};
> +
> +			port@2 {
> +				reg = <2>;
> +				label = "lan2";
> +				cpu = <&cpu_port1>;
> +			};
> +
> +			port@3 {
> +				reg = <3>;
> +				label = "wan";
> +				cpu = <&cpu_port2>;
> +			};
> +
> +			cpu_port2: port@5 {
> +				reg = <5>;
> +				label = "cpu";
> +				ethernet = <&gmac2>;
> +				phy-mode = "trgmii";
> +			};
> +
> +			cpu_port1: port@6 {
> +				reg = <6>;
> +				label = "cpu";
> +				ethernet = <&gmac1>;
> +				phy-mode = "trgmii";
> +			};
> +		};
> +	};
> +};
> +
>  Deprecated Binding
>  ------------------
>  
> 


-- 
Florian