Documentation/devicetree/bindings/cpufreq/arm_big_little_dt.txt

   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/opp/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 };