Fixed link Device Tree binding ------------------------------ Some Ethernet MACs have a "fixed link", and are not connected to a normal MDIO-managed PHY device. For those situations, a Device Tree binding allows to describe a "fixed link". Such a fixed link situation is described by creating a 'fixed-link' sub-node of the Ethernet MAC device node, with the following properties: * 'speed' (integer, mandatory), to indicate the link speed. Accepted values are 10, 100 and 1000 * 'full-duplex' (boolean, optional), to indicate that full duplex is used. When absent, half duplex is assumed. * 'pause' (boolean, optional), to indicate that pause should be enabled. * 'asym-pause' (boolean, optional), to indicate that asym_pause should be enabled. * 'link-gpios' ('gpio-list', optional), to indicate if a gpio can be read to determine if the link is up. Old, deprecated 'fixed-link' binding: * A 'fixed-link' property in the Ethernet MAC node, with 5 cells, of the form with the following accepted values: - a: emulated PHY ID, choose any but but unique to the all specified fixed-links, from 0 to 31 - b: duplex configuration: 0 for half duplex, 1 for full duplex - c: link speed in Mbits/sec, accepted values are: 10, 100 and 1000 - d: pause configuration: 0 for no pause, 1 for pause - e: asymmetric pause configuration: 0 for no asymmetric pause, 1 for asymmetric pause Examples: ethernet@0 { ... fixed-link { speed = <1000>; full-duplex; }; ... }; ethernet@1 { ... fixed-link { speed = <1000>; pause; link-gpios = <&gpio0 12 GPIO_ACTIVE_HIGH>; }; ... };