Re: [PATCH v7 1/2] dt-bindings: cpufreq: Document support for Airoha EN7581 CPUFreq
From: Rob Herring (Arm)
Date: Wed Dec 11 2024 - 11:37:30 EST
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@xxxxxxxxx>
> Reviewed-by: Ulf Hansson <ulf.hansson@xxxxxxxxxx>
> ---
> 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@xxxxxxxxxx>