Migrating this RFC from the old server for reference. This is updated
with the feedbacks that were incorporated. This consists of the
[0/3] - This overview
[1/3] - SoC, CPU and Tickless Idle power management (merged)
[2/3] - Device power management (under review)
[3/3] - Areas to be implemented next including open feedbacks
Following are the main areas to address for power management support in
1. Kernel SoC power management hook infrastructure in Zephyr
2. Kernel CPU low power state and Tickless idle power management hook
3. Device driver power management hook infrastructure
This support in Zephyr kernel is added to assist system integrator's
implementation of Power Management policy and service.
Non-goal - Zephyr kernel will not:
a) Implement any Power Management policy - The integrator's power
management service app would implement power policy
b) Implement any code to save/restore registers or SoC or device states.
- The integrator's power management service app and device drivers
should take care of that.