Add the rt linux 4.1.3-rt3 as base

[kvmfornfv.git] / kernel / Documentation / devicetree / bindings / i2c / i2c-opal.txt

diff --git a/kernel/Documentation/devicetree/bindings/i2c/i2c-opal.txt b/kernel/Documentation/devicetree/bindings/i2c/i2c-opal.txt
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+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>;
+};