1Device-tree bindings for I2C OPAL driver 2---------------------------------------- 3 4Most of the device node and properties layout is specific to the firmware and 5used by the firmware itself for configuring the port. From the linux 6perspective, the properties of use are "ibm,port-name" and "ibm,opal-id". 7 8Required properties: 9 10- reg: Port-id within a given master 11- compatible: must be "ibm,opal-i2c" 12- ibm,opal-id: Refers to a specific bus and used to identify it when calling 13 the relevant OPAL functions. 14- bus-frequency: Operating frequency of the i2c bus (in HZ). Informational for 15 linux, used by the FW though. 16 17Optional properties: 18- ibm,port-name: Firmware provides this name that uniquely identifies the i2c 19 port. 20 21The node contains a number of other properties that are used by the FW itself 22and depend on the specific hardware implementation. The example below depicts 23a P8 on-chip bus. 24 25Example: 26 27i2c-bus@0 { 28 reg = <0x0>; 29 bus-frequency = <0x61a80>; 30 compatible = "ibm,power8-i2c-port", "ibm,opal-i2c"; 31 ibm,opal-id = <0x1>; 32 ibm,port-name = "p8_00000000_e1p0"; 33 #address-cells = <0x1>; 34 phandle = <0x10000006>; 35 #size-cells = <0x0>; 36 linux,phandle = <0x10000006>; 37}; 38