+- regulator-state-mem sub-root node for Suspend-to-RAM mode
+ : suspend to memory, the device goes to sleep, but all data stored in memory,
+ only some external interrupt can wake the device.
+- regulator-state-disk sub-root node for Suspend-to-DISK mode
+ : suspend to disk, this state operates similarly to Suspend-to-RAM,
+ but includes a final step of writing memory contents to disk.
+- regulator-state-[mem/disk] node has following common properties:
+ - regulator-on-in-suspend: regulator should be on in suspend state.
+ - regulator-off-in-suspend: regulator should be off in suspend state.
+ - regulator-suspend-microvolt: regulator should be set to this voltage
+ in suspend.