Tom Rini | 53633a8 | 2024-02-29 12:33:36 -0500 | [diff] [blame] | 1 | # SPDX-License-Identifier: (GPL-2.0 OR BSD-2-Clause) |
| 2 | %YAML 1.2 |
| 3 | --- |
| 4 | $id: http://devicetree.org/schemas/dvfs/performance-domain.yaml# |
| 5 | $schema: http://devicetree.org/meta-schemas/core.yaml# |
| 6 | |
| 7 | title: Generic performance domains |
| 8 | |
| 9 | maintainers: |
| 10 | - Sudeep Holla <sudeep.holla@arm.com> |
| 11 | |
| 12 | description: |+ |
| 13 | This binding is intended for performance management of groups of devices or |
| 14 | CPUs that run in the same performance domain. Performance domains must not |
| 15 | be confused with power domains. A performance domain is defined by a set |
| 16 | of devices that always have to run at the same performance level. For a given |
| 17 | performance domain, there is a single point of control that affects all the |
| 18 | devices in the domain, making it impossible to set the performance level of |
| 19 | an individual device in the domain independently from other devices in |
| 20 | that domain. For example, a set of CPUs that share a voltage domain, and |
| 21 | have a common frequency control, is said to be in the same performance |
| 22 | domain. |
| 23 | |
| 24 | This device tree binding can be used to bind performance domain consumer |
| 25 | devices with their performance domains provided by performance domain |
| 26 | providers. A performance domain provider can be represented by any node in |
| 27 | the device tree and can provide one or more performance domains. A consumer |
| 28 | node can refer to the provider by a phandle and a set of phandle arguments |
| 29 | (so called performance domain specifiers) of length specified by the |
| 30 | \#performance-domain-cells property in the performance domain provider node. |
| 31 | |
| 32 | select: true |
| 33 | |
| 34 | properties: |
| 35 | "#performance-domain-cells": |
| 36 | description: |
| 37 | Number of cells in a performance domain specifier. Typically 0 for nodes |
| 38 | representing a single performance domain and 1 for nodes providing |
| 39 | multiple performance domains (e.g. performance controllers), but can be |
| 40 | any value as specified by device tree binding documentation of particular |
| 41 | provider. |
| 42 | enum: [ 0, 1 ] |
| 43 | |
| 44 | performance-domains: |
| 45 | $ref: /schemas/types.yaml#/definitions/phandle-array |
| 46 | description: |
| 47 | A phandle and performance domain specifier as defined by bindings of the |
| 48 | performance controller/provider specified by phandle. |
| 49 | |
| 50 | additionalProperties: true |
| 51 | |
| 52 | examples: |
| 53 | - | |
| 54 | soc { |
| 55 | #address-cells = <2>; |
| 56 | #size-cells = <2>; |
| 57 | |
| 58 | performance: performance-controller@11bc00 { |
| 59 | compatible = "mediatek,cpufreq-hw"; |
| 60 | reg = <0 0x0011bc10 0 0x120>, <0 0x0011bd30 0 0x120>; |
| 61 | |
| 62 | #performance-domain-cells = <1>; |
| 63 | }; |
| 64 | }; |
| 65 | |
| 66 | // The node above defines a performance controller that is a performance |
| 67 | // domain provider and expects one cell as its phandle argument. |
| 68 | |
| 69 | cpus { |
| 70 | #address-cells = <2>; |
| 71 | #size-cells = <0>; |
| 72 | |
| 73 | cpu@0 { |
| 74 | device_type = "cpu"; |
| 75 | compatible = "arm,cortex-a57"; |
| 76 | reg = <0x0 0x0>; |
| 77 | performance-domains = <&performance 1>; |
| 78 | }; |
| 79 | }; |