Power Manager Device Class GUIDs (Compact 7)
3/12/2014
When you configure system power states for your platform, you can specify a device power state for each device in your platform. In some cases, you may have multiple versions of the same platform where each platform uses the same set of system power states, but each platform has a different set of devices. To simplify system power state definitions across these platforms, you can specify devices by using device class GUIDs instead of exact device names. For example, you can specify that a particular system power state places all block devices in device power state D4, regardless of the actual block device that is in use on that platform. To do this, you use the block device class GUID instead of an actual block device name.
Windows Embedded Compact 7 defines the following Power Manager device class GUIDs.
Power Manager Device Class GUIDs
| Device Class | GUID |
|---|---|
Generic Devices |
|
Block Devices |
|
NDIS Miniport Devices |
|
Display Devices |
|
Touch Devices |
|
Backlight |
|
Applications obtain a list of power-managed classes by enumerating the following registry key:
HKEY_LOCAL_MACHINE\System\CurrentControlSet\Control\Power\Interfaces
If an application calls a Power Manager function without qualifying the device with a class, Power Manager assumes that the device belongs to the generic power-managed device class. To understand how you can use these class GUIDs to specify device power states for particular classes of devices, see Implement System Power States.
You can use Power Manager device class GUIDs to create class-qualified device names. Class-qualified device names are device names for power-manageable devices. A class-qualified device name is a device name that is prefixed with the class GUID rendered as a string, followed by a backslash (\). For example, {8DD679CE-8AB4-43c8-A14A-EA4963FAA715}\DSK1: refers to a power-managed block device named DSK1. For more information about device naming conventions, see Planning Your Device Driver.