brcm,bca-enet network driver Device Tree Bindings

Switch device node
==================
Only the root switch is a platform device. When probed, enet driver
recursively parses port nodes and linked switch nodes.

Required properties:

- ports: A container for child nodes representing switch ports.

- sw-type: switch type from port_type_t


Optional properties:

- label:            Describes the label associated with this switch, which
                    will become the netdev name.

- unit:             Used for ethswctl compatibility, default is 0 if not set (to be depricated).
- switch-reset:     gpio, if set, used to take switch out of reset before switch initialization


The ports container has the following properties

Required properties:

- #address-cells	: Must be 1
- #size-cells		: Must be 0

Each port children node must have the following mandatory properties:

- reg:        Describes the port address in the switch

- mac-type:   string, mac_drv_t type


An uplink/downlink port between switches in the cluster has the following
mandatory property:

- link:       Should be a phandle to another bcmbca-enet switch
              port. This port is used as the outgoing port
              towards the phandle ports. 
              netdev will not be created for ports with link.


A user port has the following optional property:

- label:      Describes the label associated with this port, which
              will become the netdev name.
              Default name will be assigned if label is not specified.

- management: sets port_info_t->is_management.
              For example used to set RGMII port as a non-lan/wan port and
              G999.1 inband management channels.

- detect: Sets port_info_t->is_detect.

- is-wan: Sets port_info_t->is_wan, capability as WAN only interface.

- error-sample: Create G999.1 error-sample netdev.

- oam-idx: Used for ethswctl compatibility (to be depricated).


Port child nodes may also contain the following optional NON-standardised
properties, described below:

- phy-handle: phandle, specifies a reference to a node representing a
              bcmbca-PHY device described in phydrv-bindings.txt.

- phy-mode:   string, operation mode of the PHY interface from phy_mii_type_t.

- xport-intf: index, for port with "XPORT" mac-type, identify which instance. 

- shrink-ipg: string, indicates shrinking 4 byte IPG to accomodate Broadcom Tag.


Port capability can be specified to one of following optional properties.
However each device can have hardware/software limitation on port capability.
Error will be shown on console if incompatible capability is set.

- wan-only:         string, indicates port is on WAN only

- wan-preferred     string, indicates port is WAN preferred

- lan-only          string, indicates port is on LAN only


Port child nodes with phy-mode set to "rgmii" also contain the following optional properties:

- rx-delay:   string, RGMII interface rx delay configuration.

- tx-delay:   string, RGMII interface tx delay configuration.

- rgmii-1p8v: string, RGMII interface is 1.8v 

- rgmii-3p3v: string, RGMII interface is 3.3v

- rgmii-intf: index, indicates which RGMII interface (if absent, index is 0) 
