linux/Documentation/devicetree/bindings/net/dsa/dsa.txt

Marvell Distributed Switch Architecture Device Tree Bindings
------------------------------------------------------------

Required properties:
- compatible		: Should be "marvell,dsa"
- #address-cells	: Must be 2, first cell is the address on the MDIO bus
			  and second cell is the address in the switch tree.
			  Second cell is used only when cascading/chaining.
- #size-cells		: Must be 0
- dsa,ethernet		: Should be a phandle to a valid Ethernet device node
- dsa,mii-bus		: Should be a phandle to a valid MDIO bus device node

Optional properties:
- interrupts		: property with a value describing the switch
			  interrupt number (not supported by the driver)

A DSA node can contain multiple switch chips which are therefore child nodes of
the parent DSA node. The maximum number of allowed child nodes is 4
(DSA_MAX_SWITCHES).
Each of these switch child nodes should have the following required properties:

- reg			: Contains two fields. The first one describes the
			  address on the MII bus. The second is the switch
			  number that must be unique in cascaded configurations
- #address-cells	: Must be 1
- #size-cells		: Must be 0

A switch child node has the following optional property:

- eeprom-length		: Set to the length of an EEPROM connected to the
			  switch. Must be set if the switch can not detect
			  the presence and/or size of a connected EEPROM,
			  otherwise optional.

A switch may have multiple "port" children nodes

Each port children node must have the following mandatory properties:
- reg			: Describes the port address in the switch
- label			: Describes the label associated with this port, special
			  labels are "cpu" to indicate a CPU port and "dsa" to
			  indicate an uplink/downlink port.

Note that a port labelled "dsa" will imply checking for the uplink phandle
described below.

Optionnal property:
- link			: Should be a list of phandles to another switch's DSA port.
			  This property is only used when switches are being
			  chained/cascaded together. This port is used as outgoing port
			  towards the phandle port, which can be more than one hop away.

- phy-handle		: Phandle to a PHY on an external MDIO bus, not the
			  switch internal one. See
			  Documentation/devicetree/bindings/net/ethernet.txt
			  for details.

- phy-mode		: String representing the connection to the designated
			  PHY node specified by the 'phy-handle' property. See
			  Documentation/devicetree/bindings/net/ethernet.txt
			  for details.

- mii-bus		: Should be a phandle to a valid MDIO bus device node.
			  This mii-bus will be used in preference to the
			  global dsa,mii-bus defined above, for this switch.

Optional subnodes:
- fixed-link		: Fixed-link subnode describing a link to a non-MDIO
			  managed entity. See
			  Documentation/devicetree/bindings/net/fixed-link.txt
			  for details.

Example:

	dsa@0 {
		compatible = "marvell,dsa";
		#address-cells = <2>;
		#size-cells = <0>;

		interrupts = <10>;
		dsa,ethernet = <&ethernet0>;
		dsa,mii-bus = <&mii_bus0>;

		switch@0 {
			#address-cells = <1>;
			#size-cells = <0>;
			reg = <16 0>;	/* MDIO address 16, switch 0 in tree */

			port@0 {
				reg = <0>;
				label = "lan1";
				phy-handle = <&phy0>;
			};

			port@1 {
				reg = <1>;
				label = "lan2";
			};

			port@5 {
				reg = <5>;
				label = "cpu";
			};

			switch0port6: port@6 {
				reg = <6>;
				label = "dsa";
				link = <&switch1port0
				        &switch2port0>;
			};
		};

		switch@1 {
			#address-cells = <1>;
			#size-cells = <0>;
			reg = <17 1>;	/* MDIO address 17, switch 1 in tree */
			mii-bus = <&mii_bus1>;
			reset-gpios = <&gpio5 1 GPIO_ACTIVE_LOW>;

			switch1port0: port@0 {
				reg = <0>;
				label = "dsa";
				link = <&switch0port6>;
			};
			switch1port1: port@1 {
				reg = <1>;
				label = "dsa";
				link = <&switch2port1>;
			};
		};

		switch@2 {
			#address-cells = <1>;
			#size-cells = <0>;
			reg = <18 2>;	/* MDIO address 18, switch 2 in tree */
			mii-bus = <&mii_bus1>;

			switch2port0: port@0 {
				reg = <0>;
				label = "dsa";
				link = <&switch1port1
				        &switch0port6>;
			};
		};
	};