Many platforms require to switch to a intermediate frequency before switching to a final frequency. Or they can switch to only particular OPPs from any OPP.
For these add another property in OPP-v2, 'opp-next'.
Refer to the bindings for more details.
Signed-off-by: Viresh Kumar viresh.kumar@linaro.org --- Documentation/devicetree/bindings/power/opp.txt | 130 ++++++++++++++++++++++++ 1 file changed, 130 insertions(+)
diff --git a/Documentation/devicetree/bindings/power/opp.txt b/Documentation/devicetree/bindings/power/opp.txt index 07959903ec32..c96dc77121b7 100644 --- a/Documentation/devicetree/bindings/power/opp.txt +++ b/Documentation/devicetree/bindings/power/opp.txt @@ -72,6 +72,9 @@ properties.
- clock-latency-ns: Specifies the maximum possible transition latency (in nanoseconds) for switching to this OPP from any other OPP. +- opp-next: It contains a list of phandles to other OPPs, to which we can switch + directly from this OPP (Explained later with examples). Missing property means + no restriction on switching to other OPPs. - turbo-mode: Marks the OPP to be used only for turbo modes. - status: Marks the node enabled/disabled.
@@ -363,6 +366,133 @@ Example 4: Handling multiple regulators }; };
+Example 5: How to use "opp-next" property ? + +1.) Switch to a intermediate OPP (entry00) before switching to any other OPP. + +/ { + cpus { + #address-cells = <1>; + #size-cells = <0>; + + cpu@0 { + compatible = "arm,cortex-a7"; + reg = <0>; + next-level-cache = <&L2>; + clocks = <&clk_controller 0>; + clock-names = "cpu"; + opp-supply = <&cpu_supply0>; + operating-points-v2 = <&cpu0_opp>; + }; + }; + + cpu0_opp: opp0 { + compatible = "operating-points-v2"; + shared-opp; + + opp_next: entry00 { + opp-khz = <500000>; + opp-microvolt = <800000>; + clock-latency-ns = <300000>; + /* Can switch to any OPP from here */ + }; + entry01 { + opp-khz = <600000>; + opp-microvolt = <800000>; + clock-latency-ns = <300000>; + opp-next = <&opp_next>; + }; + entry02 { + opp-khz = <900000>; + opp-microvolt = <970000 975000 985000>; + clock-latency-ns = <300000>; + opp-next = <&opp_next>; + }; + entry03 { + opp-khz = <1000000>; + opp-microvolt = <970000 975000 985000>; + clock-latency-ns = <300000>; + opp-next = <&opp_next>; + }; + entry04 { + opp-khz = <1100000>; + opp-microvolt = <980000 1000000 1010000>; + clock-latency-ns = <310000>; + opp-next = <&opp_next>; + }; + entry05 { + opp-khz = <1200000>; + opp-microvolt = <1025000>; + clock-latency-ns = <290000>; + opp-next = <&opp_next>; + turbo-mode; + }; + }; +}; + +2.) Can only switch to the next or previous OPP directly. + +/ { + cpus { + #address-cells = <1>; + #size-cells = <0>; + + cpu@0 { + compatible = "arm,cortex-a7"; + reg = <0>; + next-level-cache = <&L2>; + clocks = <&clk_controller 0>; + clock-names = "cpu"; + opp-supply = <&cpu_supply0>; + operating-points-v2 = <&cpu0_opp>; + }; + }; + + cpu0_opp: opp0 { + compatible = "operating-points-v2"; + shared-opp; + + opp_next0: entry00 { + opp-khz = <500000>; + opp-microvolt = <800000>; + clock-latency-ns = <300000>; + opp-next = <&opp_next1>; + }; + opp_next1: entry01 { + opp-khz = <600000>; + opp-microvolt = <800000>; + clock-latency-ns = <300000>; + opp-next = <&opp_next0>, <&opp_next2>; + }; + opp_next2: entry02 { + opp-khz = <900000>; + opp-microvolt = <970000 975000 985000>; + clock-latency-ns = <300000>; + opp-next = <&opp_next1>, <&opp_next3>; + }; + opp_next3: entry03 { + opp-khz = <1000000>; + opp-microvolt = <970000 975000 985000>; + clock-latency-ns = <300000>; + opp-next = <&opp_next2>, <&opp_next4>; + }; + opp_next4: entry04 { + opp-khz = <1100000>; + opp-microvolt = <980000 1000000 1010000>; + clock-latency-ns = <310000>; + opp-next = <&opp_next3>, <&opp_next5>; + }; + opp_next5: entry05 { + opp-khz = <1200000>; + opp-microvolt = <1025000>; + clock-latency-ns = <290000>; + opp-next = <&opp_next4>; + turbo-mode; + }; + }; +}; + +
Deprecated Bindings -------------------