Re: mixing SCMI and PSCI power domain hierarchy

[Kevin Hilman <khilman@baylibre.com>]

Ulf Hansson <ulf.hansson@linaro.org> writes:

[...]

>> Anyways, curious what you think.  I quite like this solution because it
>> solves two fairly big limitations in the SCMI PM domain implementaion
>> that exist today with one relatively simple solution.
>
> Well, I am not the one to convince in regards to DT bindings. Putting
> the DT bindings aside, I think your extensions for the SCMI Power
> Domain to support parent-domains makes perfect sense to me!
>
> In regards to the DT bindings (again, I am not the expert here), but
> maybe we could try to extend the current way we describe parent
> domains instead of inventing something entirely new. Could the below
> work?
>
> scmi_pds: protocol@11 {
>         reg = <0x11>;
>          #power-domain-cells = <1>;
>          power-domains = <&MAIN_PD>, <&WKUP_PD>; // a list of phandles
>          power-domains-child-ids = <15>, <19> ; // a list of indexes
> corresponding to the list of phandles above

Yeah, this is probably better.  I'm not crazy about introducing novel
DT bindings either.  I will make a PoC of this approach.

The catch with either approach is that it will be a long list.  e.g. on
the TI AM62L, there are 50+ SCMI IDs.

> The above said, I have also discussed this with Vincent and we thought
> it was a good idea to bring up the topic at the next monthly public
> SCMI call.
>
> It would be great if you could join, but let's see if we can find a
> reasonable slot as the current is in the middle of the night for you.
> Vincent will reach out to you as he is the one hosting the call.

Sounds great, thanks!

Kevin