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diff --git a/Documentation/devicetree/bindings/opp/opp-v2-base.yaml b/Documentation/devicetree/bindings/opp/opp-v2-base.yaml new file mode 100644 index 000000000000..ae3ae4d39843 --- /dev/null +++ b/Documentation/devicetree/bindings/opp/opp-v2-base.yaml @@ -0,0 +1,214 @@ +# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause) +%YAML 1.2 +--- +$id: http://devicetree.org/schemas/opp/opp-v2-base.yaml# +$schema: http://devicetree.org/meta-schemas/core.yaml# + +title: Generic OPP (Operating Performance Points) Common Binding + +maintainers: + - Viresh Kumar <viresh.kumar@linaro.org> + +description: | + 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 describes the OPPs belonging to a device. + +select: false + +properties: + $nodename: + pattern: '^opp-table(-[a-z0-9]+)?$' + + opp-shared: + description: + 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. + type: boolean + +patternProperties: + '^opp-?[0-9]+$': + type: object + description: + 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. These are mandatory except for the case where the OPP table is + present only to indicate dependency between devices using the opp-shared + property. + + properties: + opp-hz: + description: + 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-microvolt: + description: | + Voltage for the OPP + + 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. + minItems: 1 + maxItems: 8 # Should be enough regulators + items: + minItems: 1 + maxItems: 3 + + opp-microamp: + description: | + 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 or opp-microvolt-<name> 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. + minItems: 1 + maxItems: 8 # Should be enough regulators + + opp-level: + description: + A value representing the performance level of the device. + $ref: /schemas/types.yaml#/definitions/uint32 + + opp-peak-kBps: + description: + 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. + minItems: 1 + maxItems: 32 # Should be enough + + opp-avg-kBps: + description: + 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. + minItems: 1 + maxItems: 32 # Should be enough + + clock-latency-ns: + description: + Specifies the maximum possible transition latency (in nanoseconds) for + switching to this OPP from any other OPP. + + turbo-mode: + description: + 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. + type: boolean + + opp-suspend: + description: + 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. + type: boolean + + opp-supported-hw: + description: | + 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. + $ref: /schemas/types.yaml#/definitions/uint32-matrix + maxItems: 32 + items: + minItems: 1 + maxItems: 4 + + required-opps: + description: + 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). + $ref: /schemas/types.yaml#/definitions/phandle-array + + patternProperties: + '^opp-microvolt-': + description: + 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. + $ref: /schemas/types.yaml#/definitions/uint32-matrix + minItems: 1 + maxItems: 8 # Should be enough regulators + items: + minItems: 1 + maxItems: 3 + + '^opp-microamp-': + description: + Named opp-microamp property. Similar to opp-microvolt-<name> property, + but for microamp instead. + $ref: /schemas/types.yaml#/definitions/uint32-array + minItems: 1 + maxItems: 8 # Should be enough regulators + + dependencies: + opp-avg-kBps: [ opp-peak-kBps ] + +required: + - compatible + +additionalProperties: true + +... |