0001 Device-tree bindings for I2C OPAL driver
0002 ----------------------------------------
0003
0004 Most of the device node and properties layout is specific to the firmware and
0005 used by the firmware itself for configuring the port. From the linux
0006 perspective, the properties of use are "ibm,port-name" and "ibm,opal-id".
0007
0008 Required properties:
0009
0010 - reg: Port-id within a given master
0011 - compatible: must be "ibm,opal-i2c"
0012 - ibm,opal-id: Refers to a specific bus and used to identify it when calling
0013 the relevant OPAL functions.
0014 - bus-frequency: Operating frequency of the i2c bus (in HZ). Informational for
0015 linux, used by the FW though.
0016
0017 Optional properties:
0018 - ibm,port-name: Firmware provides this name that uniquely identifies the i2c
0019 port.
0020
0021 The node contains a number of other properties that are used by the FW itself
0022 and depend on the specific hardware implementation. The example below depicts
0023 a P8 on-chip bus.
0024
0025 Example:
0026
0027 i2c-bus@0 {
0028 reg = <0x0>;
0029 bus-frequency = <0x61a80>;
0030 compatible = "ibm,power8-i2c-port", "ibm,opal-i2c";
0031 ibm,opal-id = <0x1>;
0032 ibm,port-name = "p8_00000000_e1p0";
0033 #address-cells = <0x1>;
0034 phandle = <0x10000006>;
0035 #size-cells = <0x0>;
0036 linux,phandle = <0x10000006>;
0037 };
