Power & shutdown

POWER_POLICY_REQ

What it is

Defines a request to apply power policy.

VHAL sets this property to change car power policy. Car power policy service subscribes to this property and actually changes the power policy. The request is made by setting the VehiclePropValue with the ID of a power policy which is defined at /vendor/etc/automotive/power_policy.xml. If the given ID is not defined, car power policy service ignores the request and the current power policy is maintained.

  string: "sample_policy_id" // power policy ID

How the ID is built

A property ID is a 32-bit value packing four fields. Reading 0x11100f21 apart:

Field	Mask	Value	Means
Group	0xf0000000	0x10000000	SYSTEM
Area	0x0f000000	0x01000000	GLOBAL
Type	0x00ff0000	0x00100000	STRING
Ordinal	0x0000ffff	0x00000f21	0xf21

Reading it from an app

CarPropertyManager mgr = (CarPropertyManager)
        car.getCarManager(Car.PROPERTY_SERVICE);

CarPropertyValue<String> value =
        mgr.getProperty(VehiclePropertyIds.POWER_POLICY_REQ, 0);

This property is read-only — writes are rejected. It fires a callback whenever the value changes.