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Merge branch 'pm-opp'

* pm-opp:
  PM / OPP: Add binding for 'opp-suspend'
  PM / OPP: Allow multiple OPP tables to be passed via DT
  PM / OPP: Add new bindings to address shortcomings of existing bindings
Rafael J. Wysocki 10 years ago
parent
commit
1af858fdd2
1 changed files with 444 additions and 4 deletions
  1. 444 4
      Documentation/devicetree/bindings/power/opp.txt

+ 444 - 4
Documentation/devicetree/bindings/power/opp.txt

@@ -1,8 +1,19 @@
-* Generic OPP Interface
+Generic OPP (Operating Performance Points) Bindings
+----------------------------------------------------
 
 
-SoCs have a standard set of tuples consisting of frequency and
-voltage pairs that the device will support per voltage domain. These
-are called Operating Performance Points or OPPs.
+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:
 Properties:
 - operating-points: An array of 2-tuples items, and each item consists
 - operating-points: An array of 2-tuples items, and each item consists
@@ -23,3 +34,432 @@ cpu@0 {
 		198000  850000
 		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.
+
+Devices may want to choose OPP tables at runtime and so can provide a list of
+phandles here. But only *one* of them should be chosen at runtime. This must be
+accompanied by a corresponding "operating-points-names" property, to uniquely
+identify the OPP tables.
+
+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>".
+
+Optional properties:
+- operating-points-names: Names of OPP tables (required if multiple OPP
+  tables are present), to uniquely identify them. The same list must be present
+  for all the CPUs which are sharing clock/voltage rails and hence the OPP
+  tables.
+
+* 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
+
+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-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.
+
+- 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.
+
+- 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;
+
+		opp00 {
+			opp-hz = <1000000000>;
+			opp-microvolt = <970000 975000 985000>;
+			opp-microamp = <70000>;
+			clock-latency-ns = <300000>;
+			opp-suspend;
+		};
+		opp01 {
+			opp-hz = <1100000000>;
+			opp-microvolt = <980000 1000000 1010000>;
+			opp-microamp = <80000>;
+			clock-latency-ns = <310000>;
+		};
+		opp02 {
+			opp-hz = <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.
+		 */
+
+		opp00 {
+			opp-hz = <1000000000>;
+			opp-microvolt = <970000 975000 985000>;
+			opp-microamp = <70000>;
+			clock-latency-ns = <300000>;
+			opp-suspend;
+		};
+		opp01 {
+			opp-hz = <1100000000>;
+			opp-microvolt = <980000 1000000 1010000>;
+			opp-microamp = <80000>;
+			clock-latency-ns = <310000>;
+		};
+		opp02 {
+			opp-hz = <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;
+
+		opp00 {
+			opp-hz = <1000000000>;
+			opp-microvolt = <970000 975000 985000>;
+			opp-microamp = <70000>;
+			clock-latency-ns = <300000>;
+			opp-suspend;
+		};
+		opp01 {
+			opp-hz = <1100000000>;
+			opp-microvolt = <980000 1000000 1010000>;
+			opp-microamp = <80000>;
+			clock-latency-ns = <310000>;
+		};
+		opp02 {
+			opp-hz = <1200000000>;
+			opp-microvolt = <1025000>;
+			opp-microamp = <90000>;
+			clock-latency-ns = <290000>;
+			turbo-mode;
+		};
+	};
+
+	cluster1_opp: opp_table1 {
+		compatible = "operating-points-v2";
+		opp-shared;
+
+		opp10 {
+			opp-hz = <1300000000>;
+			opp-microvolt = <1045000 1050000 1055000>;
+			opp-microamp = <95000>;
+			clock-latency-ns = <400000>;
+			opp-suspend;
+		};
+		opp11 {
+			opp-hz = <1400000000>;
+			opp-microvolt = <1075000>;
+			opp-microamp = <100000>;
+			clock-latency-ns = <400000>;
+		};
+		opp12 {
+			opp-hz = <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;
+
+		opp00 {
+			opp-hz = <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 */
+
+		opp00 {
+			opp-hz = <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 */
+
+		opp00 {
+			opp-hz = <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: Multiple OPP tables
+
+/ {
+	cpus {
+		cpu@0 {
+			compatible = "arm,cortex-a7";
+			...
+
+			cpu-supply = <&cpu_supply>
+			operating-points-v2 = <&cpu0_opp_table_slow>, <&cpu0_opp_table_fast>;
+			operating-points-names = "slow", "fast";
+		};
+	};
+
+	cpu0_opp_table_slow: opp_table_slow {
+		compatible = "operating-points-v2";
+		status = "okay";
+		opp-shared;
+
+		opp00 {
+			opp-hz = <600000000>;
+			...
+		};
+
+		opp01 {
+			opp-hz = <800000000>;
+			...
+		};
+	};
+
+	cpu0_opp_table_fast: opp_table_fast {
+		compatible = "operating-points-v2";
+		status = "okay";
+		opp-shared;
+
+		opp10 {
+			opp-hz = <1000000000>;
+			...
+		};
+
+		opp11 {
+			opp-hz = <1100000000>;
+			...
+		};
+	};
+};