| Message ID | 20241206211145.2823-1-ansuelsmth@gmail.com |
|---|---|
| State | New |
| Headers | show |
| Series | [v7,1/2] dt-bindings: cpufreq: Document support for Airoha EN7581 CPUFreq | expand |
On Fri, 06 Dec 2024 22:11:24 +0100, Christian Marangi wrote: > 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. > > Signed-off-by: Christian Marangi <ansuelsmth@gmail.com> > Reviewed-by: Ulf Hansson <ulf.hansson@linaro.org> > --- > Changes v7: > - Add more info to the description for usage of clock and > performance-domain > - Drop redundant nodes from example > Changes v6: > - No changes > Changes v5: > - Add Reviewed-by tag > - Fix OPP node name error > - Rename cpufreq node name to power-domain > - Rename CPU node power domain name to perf > - Add model and compatible to example > Changes v4: > - Add this patch > > .../cpufreq/airoha,en7581-cpufreq.yaml | 55 +++++++++++++++++++ > 1 file changed, 55 insertions(+) > create mode 100644 Documentation/devicetree/bindings/cpufreq/airoha,en7581-cpufreq.yaml > Reviewed-by: Rob Herring (Arm) <robh@kernel.org>
diff --git a/Documentation/devicetree/bindings/cpufreq/airoha,en7581-cpufreq.yaml b/Documentation/devicetree/bindings/cpufreq/airoha,en7581-cpufreq.yaml new file mode 100644 index 000000000000..7d4510b3219c --- /dev/null +++ b/Documentation/devicetree/bindings/cpufreq/airoha,en7581-cpufreq.yaml @@ -0,0 +1,55 @@ +# 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>; + };