Re: [PATCH v1 0/5] power: domain: Add driver for a PM domain provider which controls

[Rob Herring]

On Thu, Jun 09, 2022 at 05:08:46PM +0200, Max Krummenacher wrote:
> From: Max Krummenacher <max.krummenacher@xxxxxxxxxxx>
> 
> its power enable by using a regulator.
> 
> The currently implemented PM domain providers are all specific to
> a particular system on chip.

Yes, power domains tend to be specific to an SoC... 'power-domains' is 
supposed to be power islands in a chip. Linux 'PM domains' can be 
anything...

> This series adds a PM domain provider driver which enables/disables
> a regulator to control its power state. Additionally, marked with RFC,
> it adds two commits which actually make use of the new driver to
> instantiate a power domain provider and have a number of power
> domain consumers use the power domain.
> 
> The perceived use case is to control a common power domain used by
> several devices for which not all device drivers nessesarily have
> a means to control a regulator.

Why wouldn't they have means?

> It also handles the suspend / resume use case for such devices,
> the generic power domain framework will disable the domain once the
> last device has been suspend and will enable it again before resuming
> the first device.
> The generic power domain code handles a power domain consumer
> generically outside of the driver's code. (assuming the 'power-domains'
> property references exactly one power domain).

That's Linux implementation details.

> This allows to use the "regulator-pm-pd" driver with an arbitrary
> device just by adding the 'power-domains' property to the devices
> device tree node. However the device's dt-bindings schema likely does
> not allow the property 'power-domains'.
> One way to solve this would be to allow 'power-domains' globally
> similarly how 'status' and other common properties are allowed as
> implicit properties.

No. For 'power-domains' bindings have to define how many there are and 
what each one is.

Rob