/Documentation/devicetree/bindings/power/opp.txt

 1* Generic OPP Interface
 2
 3SoCs have a standard set of tuples consisting of frequency and
 4voltage pairs that the device will support per voltage domain. These
 5are called Operating Performance Points or OPPs.
 6
 7Properties:
 8- operating-points: An array of 2-tuples items, and each item consists
 9  of frequency and voltage like <freq-kHz vol-uV>.
10	freq: clock frequency in kHz
11	vol: voltage in microvolt
12
13Examples:
14
15cpu@0 {
16	compatible = "arm,cortex-a9";
17	reg = <0>;
18	next-level-cache = <&L2>;
19	operating-points = <
20		/* kHz    uV */
21		792000  1100000
22		396000  950000
23		198000  850000
24	>;
25};