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+Generic OPP (Operating Performance Points) Bindings
+----------------------------------------------------
+
+Devices work at voltage-current-frequency combinations and some implementations
+have the liberty of choosing these. These combinations are called Operating
+Performance Points aka OPPs. This document defines bindings for these OPPs
+applicable across wide range of devices. For illustration purpose, this document
+uses CPU as a device.
+
+This document contain multiple versions of OPP binding and only one of them
+should be used per device.
+
+Binding 1: operating-points
+============================
+
+This binding only supports voltage-frequency pairs.
+
+Properties:
+- operating-points: An array of 2-tuples items, and each item consists
+ of frequency and voltage like <freq-kHz vol-uV>.
+ freq: clock frequency in kHz
+ vol: voltage in microvolt
+
+Examples:
+
+cpu@0 {
+ compatible = "arm,cortex-a9";
+ reg = <0>;
+ next-level-cache = <&L2>;
+ operating-points = <
+ /* kHz uV */
+ 792000 1100000
+ 396000 950000
+ 198000 850000
+ >;
+};
+
+
+Binding 2: operating-points-v2
+============================
+
+* Property: operating-points-v2
+
+Devices supporting OPPs must set their "operating-points-v2" property with
+phandle to a OPP table in their DT node. The OPP core will use this phandle to
+find the operating points for the device.
+
+If required, this can be extended for SoC vendor specfic bindings. Such bindings
+should be documented as Documentation/devicetree/bindings/power/<vendor>-opp.txt
+and should have a compatible description like: "operating-points-v2-<vendor>".
+
+* OPP Table Node
+
+This describes the OPPs belonging to a device. This node can have following
+properties:
+
+Required properties:
+- compatible: Allow OPPs to express their compatibility. It should be:
+ "operating-points-v2".
+
+- OPP nodes: One or more OPP nodes describing voltage-current-frequency
+ combinations. Their name isn't significant but their phandle can be used to
+ reference an OPP.
+
+Optional properties:
+- opp-shared: Indicates that device nodes using this OPP Table Node's phandle
+ switch their DVFS state together, i.e. they share clock/voltage/current lines.
+ Missing property means devices have independent clock/voltage/current lines,
+ but they share OPP tables.
+
+- status: Marks the OPP table enabled/disabled.
+
+
+* OPP Node
+
+This defines voltage-current-frequency combinations along with other related
+properties.
+
+Required properties:
+- opp-hz: Frequency in Hz, expressed as a 64-bit big-endian integer.
+
+Optional properties:
+- opp-microvolt: voltage in micro Volts.
+
+ A single regulator's voltage is specified with an array of size one or three.
+ Single entry is for target voltage and three entries are for <target min max>
+ voltages.
+
+ Entries for multiple regulators must be present in the same order as
+ regulators are specified in device's DT node.
+
+- opp-microvolt-<name>: Named opp-microvolt property. This is exactly similar to
+ the above opp-microvolt property, but allows multiple voltage ranges to be
+ provided for the same OPP. At runtime, the platform can pick a <name> and
+ matching opp-microvolt-<name> property will be enabled for all OPPs. If the
+ platform doesn't pick a specific <name> or the <name> doesn't match with any
+ opp-microvolt-<name> properties, then opp-microvolt property shall be used, if
+ present.
+
+- opp-microamp: The maximum current drawn by the device in microamperes
+ considering system specific parameters (such as transients, process, aging,
+ maximum operating temperature range etc.) as necessary. This may be used to
+ set the most efficient regulator operating mode.
+
+ Should only be set if opp-microvolt is set for the OPP.
+
+ Entries for multiple regulators must be present in the same order as
+ regulators are specified in device's DT node. If this property isn't required
+ for few regulators, then this should be marked as zero for them. If it isn't
+ required for any regulator, then this property need not be present.
+
+- opp-microamp-<name>: Named opp-microamp property. Similar to
+ opp-microvolt-<name> property, but for microamp instead.
+
+- clock-latency-ns: Specifies the maximum possible transition latency (in
+ nanoseconds) for switching to this OPP from any other OPP.
+
+- turbo-mode: Marks the OPP to be used only for turbo modes. Turbo mode is
+ available on some platforms, where the device can run over its operating
+ frequency for a short duration of time limited by the device's power, current
+ and thermal limits.
+
+- opp-suspend: Marks the OPP to be used during device suspend. Only one OPP in
+ the table should have this.
+
+- opp-supported-hw: This enables us to select only a subset of OPPs from the
+ larger OPP table, based on what version of the hardware we are running on. We
+ still can't have multiple nodes with the same opp-hz value in OPP table.
+
+ It's an user defined array containing a hierarchy of hardware version numbers,
+ supported by the OPP. For example: a platform with hierarchy of three levels
+ of versions (A, B and C), this field should be like <X Y Z>, where X
+ corresponds to Version hierarchy A, Y corresponds to version hierarchy B and Z
+ corresponds to version hierarchy C.
+
+ Each level of hierarchy is represented by a 32 bit value, and so there can be
+ only 32 different supported version per hierarchy. i.e. 1 bit per version. A
+ value of 0xFFFFFFFF will enable the OPP for all versions for that hierarchy
+ level. And a value of 0x00000000 will disable the OPP completely, and so we
+ never want that to happen.
+
+ If 32 values aren't sufficient for a version hierarchy, than that version
+ hierarchy can be contained in multiple 32 bit values. i.e. <X Y Z1 Z2> in the
+ above example, Z1 & Z2 refer to the version hierarchy Z.
+
+- status: Marks the node enabled/disabled.
+
+Example 1: Single cluster Dual-core ARM cortex A9, switch DVFS states together.
+
+/ {
+ cpus {
+ #address-cells = <1>;
+ #size-cells = <0>;
+
+ cpu@0 {
+ compatible = "arm,cortex-a9";
+ reg = <0>;
+ next-level-cache = <&L2>;
+ clocks = <&clk_controller 0>;
+ clock-names = "cpu";
+ cpu-supply = <&cpu_supply0>;
+ operating-points-v2 = <&cpu0_opp_table>;
+ };
+
+ cpu@1 {
+ compatible = "arm,cortex-a9";
+ reg = <1>;
+ next-level-cache = <&L2>;
+ clocks = <&clk_controller 0>;
+ clock-names = "cpu";
+ cpu-supply = <&cpu_supply0>;
+ operating-points-v2 = <&cpu0_opp_table>;
+ };
+ };
+
+ cpu0_opp_table: opp_table0 {
+ compatible = "operating-points-v2";
+ opp-shared;
+
+ opp@1000000000 {
+ opp-hz = /bits/ 64 <1000000000>;
+ opp-microvolt = <970000 975000 985000>;
+ opp-microamp = <70000>;
+ clock-latency-ns = <300000>;
+ opp-suspend;
+ };
+ opp@1100000000 {
+ opp-hz = /bits/ 64 <1100000000>;
+ opp-microvolt = <980000 1000000 1010000>;
+ opp-microamp = <80000>;
+ clock-latency-ns = <310000>;
+ };
+ opp@1200000000 {
+ opp-hz = /bits/ 64 <1200000000>;
+ opp-microvolt = <1025000>;
+ clock-latency-ns = <290000>;
+ turbo-mode;
+ };
+ };
+};
+
+Example 2: Single cluster, Quad-core Qualcom-krait, switches DVFS states
+independently.
+
+/ {
+ cpus {
+ #address-cells = <1>;
+ #size-cells = <0>;
+
+ cpu@0 {
+ compatible = "qcom,krait";
+ reg = <0>;
+ next-level-cache = <&L2>;
+ clocks = <&clk_controller 0>;
+ clock-names = "cpu";
+ cpu-supply = <&cpu_supply0>;
+ operating-points-v2 = <&cpu_opp_table>;
+ };
+
+ cpu@1 {
+ compatible = "qcom,krait";
+ reg = <1>;
+ next-level-cache = <&L2>;
+ clocks = <&clk_controller 1>;
+ clock-names = "cpu";
+ cpu-supply = <&cpu_supply1>;
+ operating-points-v2 = <&cpu_opp_table>;
+ };
+
+ cpu@2 {
+ compatible = "qcom,krait";
+ reg = <2>;
+ next-level-cache = <&L2>;
+ clocks = <&clk_controller 2>;
+ clock-names = "cpu";
+ cpu-supply = <&cpu_supply2>;
+ operating-points-v2 = <&cpu_opp_table>;
+ };
+
+ cpu@3 {
+ compatible = "qcom,krait";
+ reg = <3>;
+ next-level-cache = <&L2>;
+ clocks = <&clk_controller 3>;
+ clock-names = "cpu";
+ cpu-supply = <&cpu_supply3>;
+ operating-points-v2 = <&cpu_opp_table>;
+ };
+ };
+
+ cpu_opp_table: opp_table {
+ compatible = "operating-points-v2";
+
+ /*
+ * Missing opp-shared property means CPUs switch DVFS states
+ * independently.
+ */
+
+ opp@1000000000 {
+ opp-hz = /bits/ 64 <1000000000>;
+ opp-microvolt = <970000 975000 985000>;
+ opp-microamp = <70000>;
+ clock-latency-ns = <300000>;
+ opp-suspend;
+ };
+ opp@1100000000 {
+ opp-hz = /bits/ 64 <1100000000>;
+ opp-microvolt = <980000 1000000 1010000>;
+ opp-microamp = <80000>;
+ clock-latency-ns = <310000>;
+ };
+ opp@1200000000 {
+ opp-hz = /bits/ 64 <1200000000>;
+ opp-microvolt = <1025000>;
+ opp-microamp = <90000;
+ lock-latency-ns = <290000>;
+ turbo-mode;
+ };
+ };
+};
+
+Example 3: Dual-cluster, Dual-core per cluster. CPUs within a cluster switch
+DVFS state together.
+
+/ {
+ 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";
+ cpu-supply = <&cpu_supply0>;
+ operating-points-v2 = <&cluster0_opp>;
+ };
+
+ cpu@1 {
+ compatible = "arm,cortex-a7";
+ reg = <1>;
+ next-level-cache = <&L2>;
+ clocks = <&clk_controller 0>;
+ clock-names = "cpu";
+ cpu-supply = <&cpu_supply0>;
+ operating-points-v2 = <&cluster0_opp>;
+ };
+
+ cpu@100 {
+ compatible = "arm,cortex-a15";
+ reg = <100>;
+ next-level-cache = <&L2>;
+ clocks = <&clk_controller 1>;
+ clock-names = "cpu";
+ cpu-supply = <&cpu_supply1>;
+ operating-points-v2 = <&cluster1_opp>;
+ };
+
+ cpu@101 {
+ compatible = "arm,cortex-a15";
+ reg = <101>;
+ next-level-cache = <&L2>;
+ clocks = <&clk_controller 1>;
+ clock-names = "cpu";
+ cpu-supply = <&cpu_supply1>;
+ operating-points-v2 = <&cluster1_opp>;
+ };
+ };
+
+ cluster0_opp: opp_table0 {
+ compatible = "operating-points-v2";
+ opp-shared;
+
+ opp@1000000000 {
+ opp-hz = /bits/ 64 <1000000000>;
+ opp-microvolt = <970000 975000 985000>;
+ opp-microamp = <70000>;
+ clock-latency-ns = <300000>;
+ opp-suspend;
+ };
+ opp@1100000000 {
+ opp-hz = /bits/ 64 <1100000000>;
+ opp-microvolt = <980000 1000000 1010000>;
+ opp-microamp = <80000>;
+ clock-latency-ns = <310000>;
+ };
+ opp@1200000000 {
+ opp-hz = /bits/ 64 <1200000000>;
+ opp-microvolt = <1025000>;
+ opp-microamp = <90000>;
+ clock-latency-ns = <290000>;
+ turbo-mode;
+ };
+ };
+
+ cluster1_opp: opp_table1 {
+ compatible = "operating-points-v2";
+ opp-shared;
+
+ opp@1300000000 {
+ opp-hz = /bits/ 64 <1300000000>;
+ opp-microvolt = <1045000 1050000 1055000>;
+ opp-microamp = <95000>;
+ clock-latency-ns = <400000>;
+ opp-suspend;
+ };
+ opp@1400000000 {
+ opp-hz = /bits/ 64 <1400000000>;
+ opp-microvolt = <1075000>;
+ opp-microamp = <100000>;
+ clock-latency-ns = <400000>;
+ };
+ opp@1500000000 {
+ opp-hz = /bits/ 64 <1500000000>;
+ opp-microvolt = <1010000 1100000 1110000>;
+ opp-microamp = <95000>;
+ clock-latency-ns = <400000>;
+ turbo-mode;
+ };
+ };
+};
+
+Example 4: Handling multiple regulators
+
+/ {
+ cpus {
+ cpu@0 {
+ compatible = "arm,cortex-a7";
+ ...
+
+ cpu-supply = <&cpu_supply0>, <&cpu_supply1>, <&cpu_supply2>;
+ operating-points-v2 = <&cpu0_opp_table>;
+ };
+ };
+
+ cpu0_opp_table: opp_table0 {
+ compatible = "operating-points-v2";
+ opp-shared;
+
+ opp@1000000000 {
+ opp-hz = /bits/ 64 <1000000000>;
+ opp-microvolt = <970000>, /* Supply 0 */
+ <960000>, /* Supply 1 */
+ <960000>; /* Supply 2 */
+ opp-microamp = <70000>, /* Supply 0 */
+ <70000>, /* Supply 1 */
+ <70000>; /* Supply 2 */
+ clock-latency-ns = <300000>;
+ };
+
+ /* OR */
+
+ opp@1000000000 {
+ opp-hz = /bits/ 64 <1000000000>;
+ opp-microvolt = <970000 975000 985000>, /* Supply 0 */
+ <960000 965000 975000>, /* Supply 1 */
+ <960000 965000 975000>; /* Supply 2 */
+ opp-microamp = <70000>, /* Supply 0 */
+ <70000>, /* Supply 1 */
+ <70000>; /* Supply 2 */
+ clock-latency-ns = <300000>;
+ };
+
+ /* OR */
+
+ opp@1000000000 {
+ opp-hz = /bits/ 64 <1000000000>;
+ opp-microvolt = <970000 975000 985000>, /* Supply 0 */
+ <960000 965000 975000>, /* Supply 1 */
+ <960000 965000 975000>; /* Supply 2 */
+ opp-microamp = <70000>, /* Supply 0 */
+ <0>, /* Supply 1 doesn't need this */
+ <70000>; /* Supply 2 */
+ clock-latency-ns = <300000>;
+ };
+ };
+};
+
+Example 5: opp-supported-hw
+(example: three level hierarchy of versions: cuts, substrate and process)
+
+/ {
+ cpus {
+ cpu@0 {
+ compatible = "arm,cortex-a7";
+ ...
+
+ cpu-supply = <&cpu_supply>
+ operating-points-v2 = <&cpu0_opp_table_slow>;
+ };
+ };
+
+ opp_table {
+ compatible = "operating-points-v2";
+ status = "okay";
+ opp-shared;
+
+ opp@600000000 {
+ /*
+ * Supports all substrate and process versions for 0xF
+ * cuts, i.e. only first four cuts.
+ */
+ opp-supported-hw = <0xF 0xFFFFFFFF 0xFFFFFFFF>
+ opp-hz = /bits/ 64 <600000000>;
+ opp-microvolt = <900000 915000 925000>;
+ ...
+ };
+
+ opp@800000000 {
+ /*
+ * Supports:
+ * - cuts: only one, 6th cut (represented by 6th bit).
+ * - substrate: supports 16 different substrate versions
+ * - process: supports 9 different process versions
+ */
+ opp-supported-hw = <0x20 0xff0000ff 0x0000f4f0>
+ opp-hz = /bits/ 64 <800000000>;
+ opp-microvolt = <900000 915000 925000>;
+ ...
+ };
+ };
+};
+
+Example 6: opp-microvolt-<name>, opp-microamp-<name>:
+(example: device with two possible microvolt ranges: slow and fast)
+
+/ {
+ cpus {
+ cpu@0 {
+ compatible = "arm,cortex-a7";
+ ...
+
+ operating-points-v2 = <&cpu0_opp_table>;
+ };
+ };
+
+ cpu0_opp_table: opp_table0 {
+ compatible = "operating-points-v2";
+ opp-shared;
+
+ opp@1000000000 {
+ opp-hz = /bits/ 64 <1000000000>;
+ opp-microvolt-slow = <900000 915000 925000>;
+ opp-microvolt-fast = <970000 975000 985000>;
+ opp-microamp-slow = <70000>;
+ opp-microamp-fast = <71000>;
+ };
+
+ opp@1200000000 {
+ opp-hz = /bits/ 64 <1200000000>;
+ opp-microvolt-slow = <900000 915000 925000>, /* Supply vcc0 */
+ <910000 925000 935000>; /* Supply vcc1 */
+ opp-microvolt-fast = <970000 975000 985000>, /* Supply vcc0 */
+ <960000 965000 975000>; /* Supply vcc1 */
+ opp-microamp = <70000>; /* Will be used for both slow/fast */
+ };
+ };
+};
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