On Tue, Jan 5, 2021 at 9:01 AM Mark Brown [off-list ref] wrote:

On Mon, Jan 04, 2021 at 05:12:11PM -0500, Jim Quinlan wrote:

quoted

For us, the supplies are for the EP chip's power.  We have the PCIe
controller turning them "on" for power-on/resume and "off" for
power-off/suspend.  We need the "xxx-supply" property in the
controller's DT node because of the chicken-and-egg situation: if the
property was in the EP's DT node, the RC  will never discover the EP
to see that there is a regulator to turn on.   We would be happy with
a single supply name, something like "ep-power".  We would be ecstatic
to have two (ep0-power, ep1-power).

Why can't the controller look at the nodes describing devices for
standard properties?

Hi Mark,

It just feels wrong for the driver (RC) of one DT node to be acting on
a property of another driver's (EP) node, even though it is a subnode.
There is also the possibility of the EP driver acting upon the
property simultaneously; we don't really have control of what EP
device and drivers are paired with our SOCs.
In addition, this just pushes the binding name issue down a level --
what should these power supplies be called?  They are not slot power
supplies.  Can the  Broadcom STB PCIe RC driver's binding document
specify and define the properties of EP sub-nodes?

Regards,
Jim Quinlan
Broadcom STB

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