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Diffstat (limited to 'Documentation/devicetree')
| -rw-r--r-- | Documentation/devicetree/bindings/i2c/i2c-opal.txt | 37 |
1 files changed, 37 insertions, 0 deletions
diff --git a/Documentation/devicetree/bindings/i2c/i2c-opal.txt b/Documentation/devicetree/bindings/i2c/i2c-opal.txt new file mode 100644 index 000000000000..12bc61465ee5 --- /dev/null +++ b/Documentation/devicetree/bindings/i2c/i2c-opal.txt @@ -0,0 +1,37 @@ +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>; +}; |