Re: cpufreq driver for Ampere Altra

On Mon, Aug 17, 2026 at 12:42:43AM +0200, Robert Clausecker wrote:
> Dear community,
> 
> cognet has helped me by having his AI agent cook up a makeshift
> cpufreq driver using the ACPI CPPC interface.
> 
> This driver is based on D58205 with expansions so it works with
> PCC.  You can find the code here:
> 
> https://github.com/clausecker/freebsd-src/tree/acpi_cppc
> 
> Please enjoy!
> 
> Clusteradm in particular might want to consider this driver to
> reduce power costs.
> 

Hi,

Just to be clear, it won't be merged as-is. I'm waiting for D55474 to          
eventually land, and then I'll adapt the code to work with it.                 
But in the meanwhile, that code is there, it seems to work, so if it can       
be useful for others, that's great.                                            
It should support ACPI CPPC both using System Memory, and PCC, which is        
what most arm boards using ACPI seem to be using.                              

Olivier