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Documentation / devicetree / bindings / cpufreq / arm_big_little_dt.txt




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Based on kernel version 3.15.4. Page generated on 2014-07-07 09:00 EST.

1	Generic ARM big LITTLE cpufreq driver's DT glue
2	-----------------------------------------------
3	
4	This is DT specific glue layer for generic cpufreq driver for big LITTLE
5	systems.
6	
7	Both required and optional properties listed below must be defined
8	under node /cpus/cpu@x. Where x is the first cpu inside a cluster.
9	
10	FIXME: Cpus should boot in the order specified in DT and all cpus for a cluster
11	must be present contiguously. Generic DT driver will check only node 'x' for
12	cpu:x.
13	
14	Required properties:
15	- operating-points: Refer to Documentation/devicetree/bindings/power/opp.txt
16	  for details
17	
18	Optional properties:
19	- clock-latency: Specify the possible maximum transition latency for clock,
20	  in unit of nanoseconds.
21	
22	Examples:
23	
24	cpus {
25		#address-cells = <1>;
26		#size-cells = <0>;
27	
28		cpu@0 {
29			compatible = "arm,cortex-a15";
30			reg = <0>;
31			next-level-cache = <&L2>;
32			operating-points = <
33				/* kHz    uV */
34				792000  1100000
35				396000  950000
36				198000  850000
37			>;
38			clock-latency = <61036>; /* two CLK32 periods */
39		};
40	
41		cpu@1 {
42			compatible = "arm,cortex-a15";
43			reg = <1>;
44			next-level-cache = <&L2>;
45		};
46	
47		cpu@100 {
48			compatible = "arm,cortex-a7";
49			reg = <100>;
50			next-level-cache = <&L2>;
51			operating-points = <
52				/* kHz    uV */
53				792000  950000
54				396000  750000
55				198000  450000
56			>;
57			clock-latency = <61036>; /* two CLK32 periods */
58		};
59	
60		cpu@101 {
61			compatible = "arm,cortex-a7";
62			reg = <101>;
63			next-level-cache = <&L2>;
64		};
65	};
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