1*c66ec88fSEmmanuel VadotDevice-tree bindings for I2C OPAL driver
2*c66ec88fSEmmanuel Vadot----------------------------------------
3*c66ec88fSEmmanuel Vadot
4*c66ec88fSEmmanuel VadotMost of the device node and properties layout is specific to the firmware and
5*c66ec88fSEmmanuel Vadotused by the firmware itself for configuring the port. From the linux
6*c66ec88fSEmmanuel Vadotperspective, the properties of use are "ibm,port-name" and "ibm,opal-id".
7*c66ec88fSEmmanuel Vadot
8*c66ec88fSEmmanuel VadotRequired properties:
9*c66ec88fSEmmanuel Vadot
10*c66ec88fSEmmanuel Vadot- reg: Port-id within a given master
11*c66ec88fSEmmanuel Vadot- compatible: must be "ibm,opal-i2c"
12*c66ec88fSEmmanuel Vadot- ibm,opal-id: Refers to a specific bus and used to identify it when calling
13*c66ec88fSEmmanuel Vadot	       the relevant OPAL functions.
14*c66ec88fSEmmanuel Vadot- bus-frequency: Operating frequency of the i2c bus (in HZ). Informational for
15*c66ec88fSEmmanuel Vadot		 linux, used by the FW though.
16*c66ec88fSEmmanuel Vadot
17*c66ec88fSEmmanuel VadotOptional properties:
18*c66ec88fSEmmanuel Vadot- ibm,port-name: Firmware provides this name that uniquely identifies the i2c
19*c66ec88fSEmmanuel Vadot		 port.
20*c66ec88fSEmmanuel Vadot
21*c66ec88fSEmmanuel VadotThe node contains a number of other properties that are used by the FW itself
22*c66ec88fSEmmanuel Vadotand depend on the specific hardware implementation. The example below depicts
23*c66ec88fSEmmanuel Vadota P8 on-chip bus.
24*c66ec88fSEmmanuel Vadot
25*c66ec88fSEmmanuel VadotExample:
26*c66ec88fSEmmanuel Vadot
27*c66ec88fSEmmanuel Vadoti2c-bus@0 {
28*c66ec88fSEmmanuel Vadot	reg = <0x0>;
29*c66ec88fSEmmanuel Vadot	bus-frequency = <0x61a80>;
30*c66ec88fSEmmanuel Vadot	compatible = "ibm,power8-i2c-port", "ibm,opal-i2c";
31*c66ec88fSEmmanuel Vadot	ibm,opal-id = <0x1>;
32*c66ec88fSEmmanuel Vadot	ibm,port-name = "p8_00000000_e1p0";
33*c66ec88fSEmmanuel Vadot	#address-cells = <0x1>;
34*c66ec88fSEmmanuel Vadot	phandle = <0x10000006>;
35*c66ec88fSEmmanuel Vadot	#size-cells = <0x0>;
36*c66ec88fSEmmanuel Vadot	linux,phandle = <0x10000006>;
37*c66ec88fSEmmanuel Vadot};
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