Documentation/devicetree/bindings/cpufreq/airoha,en7581-cpufreq.yaml

Source file repositories/reference/linux-study-clean/Documentation/devicetree/bindings/cpufreq/airoha,en7581-cpufreq.yaml

File Facts

System
Linux kernel
Corpus path
Documentation/devicetree/bindings/cpufreq/airoha,en7581-cpufreq.yaml
Extension
.yaml
Size
1315 bytes
Lines
56
Domain
Support Tooling And Documentation
Bucket
Documentation
Inferred role
Support Tooling And Documentation: configuration, schema, or hardware description
Status
atlas-only

Why This File Exists

Repository support layer: documentation, build tooling, samples, user-space helper tools, generated initramfs support, licenses, and validation utilities.

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Annotated Snippet

# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
%YAML 1.2
---
$id: http://devicetree.org/schemas/cpufreq/airoha,en7581-cpufreq.yaml#
$schema: http://devicetree.org/meta-schemas/core.yaml#

title: Airoha EN7581 CPUFreq

maintainers:
  - Christian Marangi <ansuelsmth@gmail.com>

description: |
  On newer Airoha SoC, CPU Frequency is scaled indirectly with SMC commands
  to ATF.

  A virtual clock is exposed. This virtual clock is a get-only clock and
  is used to expose the current global CPU clock. The frequency info comes
  by the output of the SMC command that reports the clock in MHz.

  The SMC sets the CPU clock by providing an index, this is modelled as
  performance states in a power domain.

  CPUs can't be individually scaled as the CPU frequency is shared across
  all CPUs and is global.

properties:
  compatible:
    const: airoha,en7581-cpufreq

  '#clock-cells':
    const: 0

  '#power-domain-cells':
    const: 0

  operating-points-v2: true

required:
  - compatible
  - '#clock-cells'
  - '#power-domain-cells'
  - operating-points-v2

additionalProperties: false

examples:
  - |
    performance-domain {
        compatible = "airoha,en7581-cpufreq";

        operating-points-v2 = <&cpu_smcc_opp_table>;

        #power-domain-cells = <0>;
        #clock-cells = <0>;
    };

Annotation

Implementation Notes