1 Device-tree bindings for I2C OPAL driver 1 Device-tree bindings for I2C OPAL driver
2 ---------------------------------------- 2 ----------------------------------------
3 3
4 Most of the device node and properties layout 4 Most of the device node and properties layout is specific to the firmware and
5 used by the firmware itself for configuring th 5 used by the firmware itself for configuring the port. From the linux
6 perspective, the properties of use are "ibm,po 6 perspective, the properties of use are "ibm,port-name" and "ibm,opal-id".
7 7
8 Required properties: 8 Required properties:
9 9
10 - reg: Port-id within a given master 10 - reg: Port-id within a given master
11 - compatible: must be "ibm,opal-i2c" 11 - compatible: must be "ibm,opal-i2c"
12 - ibm,opal-id: Refers to a specific bus and us 12 - ibm,opal-id: Refers to a specific bus and used to identify it when calling
13 the relevant OPAL functions. 13 the relevant OPAL functions.
14 - bus-frequency: Operating frequency of the i2 14 - bus-frequency: Operating frequency of the i2c bus (in HZ). Informational for
15 linux, used by the FW though. 15 linux, used by the FW though.
16 16
17 Optional properties: 17 Optional properties:
18 - ibm,port-name: Firmware provides this name t 18 - ibm,port-name: Firmware provides this name that uniquely identifies the i2c
19 port. 19 port.
20 20
21 The node contains a number of other properties 21 The node contains a number of other properties that are used by the FW itself
22 and depend on the specific hardware implementa 22 and depend on the specific hardware implementation. The example below depicts
23 a P8 on-chip bus. 23 a P8 on-chip bus.
24 24
25 Example: 25 Example:
26 26
27 i2c-bus@0 { 27 i2c-bus@0 {
28 reg = <0x0>; 28 reg = <0x0>;
29 bus-frequency = <0x61a80>; 29 bus-frequency = <0x61a80>;
30 compatible = "ibm,power8-i2c-port", "i 30 compatible = "ibm,power8-i2c-port", "ibm,opal-i2c";
31 ibm,opal-id = <0x1>; 31 ibm,opal-id = <0x1>;
32 ibm,port-name = "p8_00000000_e1p0"; 32 ibm,port-name = "p8_00000000_e1p0";
33 #address-cells = <0x1>; 33 #address-cells = <0x1>;
34 phandle = <0x10000006>; 34 phandle = <0x10000006>;
35 #size-cells = <0x0>; 35 #size-cells = <0x0>;
36 linux,phandle = <0x10000006>; 36 linux,phandle = <0x10000006>;
37 }; 37 };
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