On Thu, 5 Nov 2020 at 11:40, Viresh Kumar <viresh.kumar@xxxxxxxxxx> wrote: > > On 05-11-20, 11:34, Ulf Hansson wrote: > > I am not objecting about scaling the voltage through a regulator, > > that's fine to me. However, encoding a power domain as a regulator > > (even if it may seem like a regulator) isn't. Well, unless Mark Brown > > has changed his mind about this. > > > > In this case, it seems like the regulator supply belongs in the > > description of the power domain provider. > > Okay, I wasn't sure if it is a power domain or a regulator here. Btw, > how do we identify if it is a power domain or a regulator ? Good question. It's not a crystal clear line in between them, I think. A power domain to me, means that some part of a silicon (a group of controllers or just a single piece, for example) needs some kind of resource (typically a power rail) to be enabled to be functional, to start with. If there are operating points involved, that's also a clear indication to me, that it's not a regular regulator. Maybe we should try to specify this more exactly in some documentation, somewhere. > > > > In case of Qcom earlier (when we added the performance-state stuff), > > > the eventual hardware was out of kernel's control and we didn't wanted > > > (allowed) to model it as a virtual regulator just to pass the votes to > > > the RPM. And so we did what we did. > > > > > > But if the hardware (where the voltage is required to be changed) is > > > indeed a regulator and is modeled as one, then what Dmitry has done > > > looks okay. i.e. add a supply in the device's node and microvolt > > > property in the DT entries. > > > > I guess I haven't paid enough attention how power domain regulators > > are being described then. I was under the impression that the CPUfreq > > case was a bit specific - and we had legacy bindings to stick with. > > > > Can you point me to some other existing examples of where power domain > > regulators are specified as a regulator in each device's node? > > No, I thought it is a regulator here and not a power domain. Okay, thanks! Kind regards Uffe
