| Device-tree bindings for I2C OPAL driver | |
| ---------------------------------------- | |
| Most of the device node and properties layout is specific to the firmware and | |
| used by the firmware itself for configuring the port. From the linux | |
| perspective, the properties of use are "ibm,port-name" and "ibm,opal-id". | |
| Required properties: | |
| - reg: Port-id within a given master | |
| - compatible: must be "ibm,opal-i2c" | |
| - ibm,opal-id: Refers to a specific bus and used to identify it when calling | |
| the relevant OPAL functions. | |
| - bus-frequency: Operating frequency of the i2c bus (in HZ). Informational for | |
| linux, used by the FW though. | |
| Optional properties: | |
| - ibm,port-name: Firmware provides this name that uniquely identifies the i2c | |
| port. | |
| The node contains a number of other properties that are used by the FW itself | |
| and depend on the specific hardware implementation. The example below depicts | |
| a P8 on-chip bus. | |
| Example: | |
| i2c-bus@0 { | |
| reg = <0x0>; | |
| bus-frequency = <0x61a80>; | |
| compatible = "ibm,power8-i2c-port", "ibm,opal-i2c"; | |
| ibm,opal-id = <0x1>; | |
| ibm,port-name = "p8_00000000_e1p0"; | |
| #address-cells = <0x1>; | |
| phandle = <0x10000006>; | |
| #size-cells = <0x0>; | |
| linux,phandle = <0x10000006>; | |
| }; |