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diff --git a/Documentation/devicetree/bindings/opp/opp.txt b/Documentation/devicetree/bindings/opp/opp.txt new file mode 100644 index 000000000..9847dfeef --- /dev/null +++ b/Documentation/devicetree/bindings/opp/opp.txt @@ -0,0 +1,570 @@ +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. + +This can contain more than one phandle for power domain providers that provide +multiple power domains. That is, one phandle for each power domain. If only one +phandle is available, then the same OPP table will be used for all power domains +provided by the power domain provider. + +If required, this can be extended for SoC vendor specific 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. This is a + required property for all device nodes, unless another "required" property to + uniquely identify the OPP nodes exists. Devices like power domains must have + another (implementation dependent) property. + +- opp-peak-kBps: Peak bandwidth in kilobytes per second, expressed as an array + of 32-bit big-endian integers. Each element of the array represents the + peak bandwidth value of each interconnect path. The number of elements should + match the number of interconnect paths. + +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 shall be provided in the same field separated + by angular brackets <>. The OPP binding doesn't provide any provisions to + relate the values to their power supplies or the order in which the supplies + need to be configured and that is left for the implementation specific + binding. + + Entries for all regulators shall be of the same size, i.e. either all use a + single value or triplets. + +- 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 shall be provided in the same field separated + by angular brackets <>. If current values aren't required for a regulator, + then it shall be filled with 0. If current values aren't required for any of + the regulators, then this field is not required. The OPP binding doesn't + provide any provisions to relate the values to their power supplies or the + order in which the supplies need to be configured and that is left for the + implementation specific binding. + +- opp-microamp-<name>: Named opp-microamp property. Similar to + opp-microvolt-<name> property, but for microamp instead. + +- opp-level: A value representing the performance level of the device, + expressed as a 32-bit integer. + +- opp-avg-kBps: Average bandwidth in kilobytes per second, expressed as an array + of 32-bit big-endian integers. Each element of the array represents the + average bandwidth value of each interconnect path. The number of elements + should match the number of interconnect paths. This property is only + meaningful in OPP tables where opp-peak-kBps is 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. If multiple OPPs + in the table have this, the OPP with highest opp-hz will be used. + +- opp-supported-hw: This property allows a platform to enable only a subset of + the OPPs from the larger set present in the OPP table, based on the current + version of the hardware (already known to the operating system). + + Each block present in the array of blocks in this property, represents a + sub-group of hardware versions supported by the OPP. i.e. <sub-group A>, + <sub-group B>, etc. The OPP will be enabled if _any_ of these sub-groups match + the hardware's version. + + Each sub-group is a platform defined array representing the hierarchy of + hardware versions supported by the platform. For a platform with three + hierarchical levels of version (X.Y.Z), this field shall look like + + opp-supported-hw = <X1 Y1 Z1>, <X2 Y2 Z2>, <X3 Y3 Z3>. + + Each level (eg. X1) in version hierarchy is represented by a 32 bit value, one + bit per version and so there can be maximum 32 versions per level. Logical AND + (&) operation is performed for each level with the hardware's level version + and a non-zero output for _all_ the levels in a sub-group means the OPP is + supported by hardware. A value of 0xFFFFFFFF for each level in the sub-group + will enable the OPP for all versions for the hardware. + +- status: Marks the node enabled/disabled. + +- required-opps: This contains phandle to an OPP node in another device's OPP + table. It may contain an array of phandles, where each phandle points to an + OPP of a different device. It should not contain multiple phandles to the OPP + nodes in the same OPP table. This specifies the minimum required OPP of the + device(s), whose OPP's phandle is present in this property, for the + functioning of the current device at the current OPP (where this property is + present). + +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 = <975000 970000 985000>; + opp-microamp = <70000>; + clock-latency-ns = <300000>; + opp-suspend; + }; + opp-1100000000 { + opp-hz = /bits/ 64 <1100000000>; + opp-microvolt = <1000000 980000 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 = <975000 970000 985000>; + opp-microamp = <70000>; + clock-latency-ns = <300000>; + opp-suspend; + }; + opp-1100000000 { + opp-hz = /bits/ 64 <1100000000>; + opp-microvolt = <1000000 980000 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 = <975000 970000 985000>; + opp-microamp = <70000>; + clock-latency-ns = <300000>; + opp-suspend; + }; + opp-1100000000 { + opp-hz = /bits/ 64 <1100000000>; + opp-microvolt = <1000000 980000 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 = <1050000 1045000 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 = <1100000 1010000 1110000>; + opp-microamp = <95000>; + clock-latency-ns = <400000>; + turbo-mode; + }; + }; +}; + +Example 4: Handling multiple regulators + +/ { + cpus { + cpu@0 { + compatible = "vendor,cpu-type"; + ... + + vcc0-supply = <&cpu_supply0>; + vcc1-supply = <&cpu_supply1>; + vcc2-supply = <&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 = <975000 970000 985000>, /* Supply 0 */ + <965000 960000 975000>, /* Supply 1 */ + <965000 960000 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 = <975000 970000 985000>, /* Supply 0 */ + <965000 960000 975000>, /* Supply 1 */ + <965000 960000 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"; + 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-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-900000000 { + /* + * Supports: + * - All cuts and substrate where process version is 0x2. + * - All cuts and process where substrate version is 0x2. + */ + opp-supported-hw = <0xFFFFFFFF 0xFFFFFFFF 0x02>, <0xFFFFFFFF 0x01 0xFFFFFFFF> + opp-hz = /bits/ 64 <900000000>; + ... + }; + }; +}; + +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 = <915000 900000 925000>; + opp-microvolt-fast = <975000 970000 985000>; + opp-microamp-slow = <70000>; + opp-microamp-fast = <71000>; + }; + + opp-1200000000 { + opp-hz = /bits/ 64 <1200000000>; + opp-microvolt-slow = <915000 900000 925000>, /* Supply vcc0 */ + <925000 910000 935000>; /* Supply vcc1 */ + opp-microvolt-fast = <975000 970000 985000>, /* Supply vcc0 */ + <965000 960000 975000>; /* Supply vcc1 */ + opp-microamp = <70000>; /* Will be used for both slow/fast */ + }; + }; +}; |