Re: Question regarding scmi_perf_domain.c

[Sudeep Holla <sudeep.holla@arm.com>]

On Tue, Oct 10, 2023 at 01:15:26PM +0000, Peng Fan wrote:
> 
> Thanks for the detailed explanation, so power-domains property could be
> used both for power domain or performance domain. But if one
> device has both power domain and performance domain. Only power-domain
> property is not enough. I may understand wrong, let me look into the code.
> 

I haven't tried this but something I could come up quick wit Juno DTS
as reference:

We can change something like this:

      scmi_dvfs: protocol@13 {
              reg = <0x13>;
-             #clock-cells = <1>;
+             #power-domain-cells = <1>;
              mbox-names = "tx", "rx";
              mboxes = <&mailbox 1 0 &mailbox 1 1>;
              shmem = <&cpu_scp_hpri0 &cpu_scp_hpri1>;
      };

And then in the consumer node(taking GPU as it has both perf and power
domains). The CPUs are simpler as don't have explicit power domains, some
Qcom platforms do use that. Anyways I would change GPU node like this.
Hope this clarifies things for you.

 &gpu {
-       clocks = <&scmi_dvfs 2>;
-       power-domains = <&scmi_devpd 9>;
+       power-domains = <&scmi_dvfs 2 &scmi_devpd 9>;
+       power-domain-names = "perf", "power";
        status = "disabled";
 };

-- 
Regards,
Sudeep