EVT_UCM_CONNECTOR_SET_POWER_ROLE callback function (ucmmanager.h)

The client driver's implementation of the EVT_UCM_CONNECTOR_SET_POWER_ROLE event callback function that sets the power role of the connector to the specified role when attached to a partner connector.

Syntax

EVT_UCM_CONNECTOR_SET_POWER_ROLE EvtUcmConnectorSetPowerRole;

NTSTATUS EvtUcmConnectorSetPowerRole(
  [in] UCMCONNECTOR Connector,
  [in] UCM_POWER_ROLE PowerRole
)
{...}

Parameters

[in] Connector

Handle to the connector that the client driver received in a previous call to the UcmConnectorCreate method.

[in] PowerRole

A UCM_POWER_ROLE-typed flag that specifies the role to set.

Return value

If the operation is successful, the callback function must return STATUS_SUCCESS, or another status value for which NT_SUCCESS(status) equals TRUE. Otherwise it must return a status value for which NT_SUCCESS(status) equals FALSE.

Remarks

To register an EVT_UCM_CONNECTOR_SET_POWER_ROLE callback function, the client must call UcmConnectorCreate.

The USB connector manager framework extension (UcmCx) can request either UcmPowerRoleSink or UcmPowerRoleSource. If the port is already in the requested role, the client driver can complete the request without any changes. Otherwise, it starts a power-role swap operation (PR_Swap). The driver calls UcmConnectorPowerDirectionChanged to notify UcmCx about the success or failure of that operation. The driver can call that method within the callback function.

The role persists for the current connection.

If a role-swap operation is pending, UcmCx does not request another role swap. Those operations are serialized across power and data role swaps.

After the swap operation completes, if the partner port sends a PR_Swap request, the client driver must reject the request.

Examples

EVT_UCM_CONNECTOR_SET_POWER_ROLE     EvtSetPowerRole;  

NTSTATUS  
EvtSetPowerRole(  
    UCMCONNECTOR Connector,  
    UCM_POWER_ROLE PowerRole  
    )  
{  
    PCONNECTOR_CONTEXT connCtx;  
  
    TRACE_INFO("EvtSetPowerRole(%!UCM_POWER_ROLE!) Entry", PowerRole);  
  
    connCtx = GetConnectorContext(Connector);  

    //PR_Swap operation.  
  
  
    TRACE_FUNC_EXIT();  
    return STATUS_SUCCESS;  
}  

Requirements

See also

UcmConnectorCreate