pm: Add reinit-power-states DT binding property

This property allows defining one or more power-states phandles in which
a peripheral loses its configuration, and must be reinitialized.

States below and including S2RAM are inherently assumed to require
reinit, this property is intended to cover the exceptions outside
of this common use case.

It is intended to assist drivers in preventing the SoC from entering
these power states during critical code sections, as well as indicate
to power management services when a peripheral needs reinitialization.

Signed-off-by: Kenneth J. Miller <[email protected]>

Author: knthm

dts/bindings/base/pm.yaml

@@ -30,3 +30,12 @@ properties:
     description: |
       Automatically configure the device for runtime power management after the
       init function runs.
+
+  reinit-power-states:
+    type: phandles
+    description: |
+      Specifies special power states where a peripheral requires
+      reinitialization due to configuration loss.
+
+      While states at or beyond S2RAM are naturally assumed to need
+      reinitialization, this property highlights the exceptions to that rule.