PO_FX_COMPONENT structure

The PO_FX_COMPONENT structure describes the power state attributes of a component in a device.

Syntax


typedef struct _PO_FX_COMPONENT {
  GUID                        Id;
  ULONG                       IdleStateCount;
  ULONG                       DeepestWakeableIdleState;
  PPO_FX_COMPONENT_IDLE_STATE IdleStates;
} PO_FX_COMPONENT, *PPO_FX_COMPONENT;

Members

Id

A component ID that uniquely identifies this component with respect to the other components in the device. The driver should specify a nonzero value for this member if the power management framework (PoFx) requires a component ID to distinguish this component from other, similar components in the same device. This member is optional. If this member is not used, it must be set to all zeros.

IdleStateCount

The number of elements in the array that is pointed to by the IdleStates member. Additionally, this member specifies the number of Fx power states that the component supports. A component must support at least one Fx state (F0).

DeepestWakeableIdleState

The index of the deepest Fx state from which the component can wake. Specify 0 for F0, 1 for F1, and so on. This index must be less than IdleStateCount.

IdleStates

A pointer to a PO_FX_COMPONENT_IDLE_STATE array. The length of this array is specified by the IdleStateCount member. Each array element specifies the attributes of an Fx power state that is supported by the component. Element 0 describes F0, element 1 describes F1, and so on.

Remarks

When a device driver registers a device with PoFx, the driver supplies a PO_FX_DEVICE structure that holds the registration information. This structure contains an array of PO_FX_COMPONENT structures. The elements in this array describe the power attributes of the individual components in the device. PoFx uses the information in this array to manage the power settings of these components.

The Id member contains a component ID that PoFx can use to uniquely identify a component. Do not confuse the component ID with the component index, which a routine such as PoFxActivateComponent uses to identify a component in a registered device. A component index is an index into the Components array in the PO_FX_DEVICE structure that the device driver used to register the device with PoFx. If the Components array contains N elements, component indexes are integer values in the range 0 to N–1. In contrast, a component ID is a GUID value.

Requirements

Version

Supported starting with Windows 8.

Header

Wdm.h

See also

PO_FX_COMPONENT_IDLE_STATE
PO_FX_DEVICE

 

 

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