iokit/IOKit/IOService.h

1335     Most calls to <code>PMinit</code> are followed by calls to @link joinPMtree joinPMtree@/link and @link registerPowerDriver registerPowerDriver@/link. */
1342     Calling <code>PMstop</code> cleans up for the three power management initialization calls: @link PMinit PMinit@/link, @link joinPMtree joinPMtree@/link, and @link registerPowerDriver registerPowerDriver@/link. */
1354 /*! @function registerPowerDriver
1357     Most drivers do not need to override <code>registerPowerDriver</code>. A nub may override <code>registerPowerDriver</code> if it needs to arrange its children in the power plane differently than the default placement, but this is uncommon.
1363     virtual IOReturn registerPowerDriver(
1600     Calls to @link PMinit PMinit@/link and @link registerPowerDriver registerPowerDriver@/link enable power management to change a device's power state using <code>setPowerState</code>. <code>setPowerState</code> is called in a clean and separate thread context.