power.c

怎样在win2000下构造驱动程序znsoft_Serial2000_demo.ZIP

   case IRP_MN_QUERY_POWER:

      SerialDump (SERPNPPOWER, ("SERIAL: Got IRP_MN_QUERY_POWER Irp\n"));

      //
      // Check if we have a wait-wake pending and if so,
      // ensure we don't power down too far.
      //


      if (pDevExt->PendingWakeIrp != NULL || pDevExt->SendWaitWake) {
         if (pIrpStack->Parameters.Power.Type == DevicePowerState
             && pIrpStack->Parameters.Power.State.DeviceState
             > pDevExt->DeviceWake) {
            status = PIrp->IoStatus.Status = STATUS_INVALID_DEVICE_STATE;
            PoStartNextPowerIrp(PIrp);
            SerialCompleteRequest(pDevExt, PIrp, IO_NO_INCREMENT);
            return status;
         }
      }

      //
      // If no wait-wake, always successful
      //

      PIrp->IoStatus.Status = STATUS_SUCCESS;
      status = STATUS_SUCCESS;
      PoStartNextPowerIrp(PIrp);
      IoSkipCurrentIrpStackLocation(PIrp);
      return SerialPoCallDriver(pDevExt, pLowerDevObj, PIrp);

   }   // switch (pIrpStack->MinorFunction)


   PowerExit:;

   PoStartNextPowerIrp(PIrp);


   //
   // Pass to the lower driver
   //
   IoSkipCurrentIrpStackLocation(PIrp);
   status = SerialPoCallDriver(pDevExt, pLowerDevObj, PIrp);

   return status;
}





NTSTATUS
SerialSetPowerD0(IN PDEVICE_OBJECT PDevObj, IN PIRP PIrp)

/*++

Routine Description:

    This routine Decides if we need to pass the power Irp down the stack
    or not.  It then either sets up a completion handler to finish the
    initialization or calls the completion handler directly.

Arguments:

    PDevObj - Pointer to the devobj we are changing power state on

    PIrp - Pointer to the IRP for the current request

Return Value:

    Return status of either PoCallDriver of the call to the initialization
    routine.


--*/

{
   PSERIAL_DEVICE_EXTENSION pDevExt = PDevObj->DeviceExtension;
   PIO_STACK_LOCATION pIrpStack = IoGetCurrentIrpStackLocation(PIrp);
   NTSTATUS status;

   PAGED_CODE();

   SerialDump(SERTRACECALLS, ("SERIAL: In SerialSetPowerD0\n"));
   SerialDump(SERPNPPOWER, ("SERIAL: SetPowerD0 has IRP %x\n", PIrp));

   ASSERT(pDevExt->LowerDeviceObject);

   //
   // Set up completion to init device when it is on
   //

   KeClearEvent(&pDevExt->PowerD0Event);


   IoCopyCurrentIrpStackLocationToNext(PIrp);
   IoSetCompletionRoutine(PIrp, SerialSyncCompletion, &pDevExt->PowerD0Event,
                          TRUE, TRUE, TRUE);

   SerialDump(SERPNPPOWER, ("SERIAL: Calling next driver\n"));

   status = PoCallDriver(pDevExt->LowerDeviceObject, PIrp);

   if (status == STATUS_PENDING) {
      SerialDump(SERPNPPOWER, ("SERIAL: Waiting for next driver\n"));
      KeWaitForSingleObject (&pDevExt->PowerD0Event, Executive, KernelMode,
                             FALSE, NULL);
   } else {
      if (!NT_SUCCESS(status)) {
         PIrp->IoStatus.Status = status;
         PoStartNextPowerIrp(PIrp);
         SerialCompleteRequest(pDevExt, PIrp, IO_NO_INCREMENT);
         return status;
      }
   }

   if (!NT_SUCCESS(PIrp->IoStatus.Status)) {
      status = PIrp->IoStatus.Status;
      PoStartNextPowerIrp(PIrp);
      SerialCompleteRequest(pDevExt, PIrp, IO_NO_INCREMENT);
      return status;
   }

   //
   // Restore the device
   //

   pDevExt->PowerState = PowerDeviceD0;

   //
   // Theoretically we could change states in the middle of processing
   // the restore which would result in a bad PKINTERRUPT being used
   // in SerialRestoreDeviceState().
   //

   if (pDevExt->PNPState == SERIAL_PNP_STARTED) {
      SerialRestoreDeviceState(pDevExt);
   }

   //
   // Now that we are powered up, call PoSetPowerState
   //

   PoSetPowerState(PDevObj, pIrpStack->Parameters.Power.Type,
                   pIrpStack->Parameters.Power.State);

   PoStartNextPowerIrp(PIrp);
   SerialCompleteRequest(pDevExt, PIrp, IO_NO_INCREMENT);


   SerialDump(SERTRACECALLS, ("SERIAL: Leaving SerialSetPowerD0\n"));
   return status;
}


NTSTATUS
SerialGotoPowerState(IN PDEVICE_OBJECT PDevObj,
                     IN PSERIAL_DEVICE_EXTENSION PDevExt,
                     IN DEVICE_POWER_STATE DevPowerState)
/*++

Routine Description:

    This routine causes the driver to request the stack go to a particular
    power state.

Arguments:

    PDevObj - Pointer to the device object for this device

    PDevExt - Pointer to the device extension we are working from

    DevPowerState - the power state we wish to go to

Return Value:

    The function value is the final status of the call


--*/
{
   KEVENT gotoPowEvent;
   NTSTATUS status;
   POWER_STATE powerState;

   PAGED_CODE();

   SerialDump(SERTRACECALLS, ("SERIAL: In SerialGotoPowerState\n"));

   powerState.DeviceState = DevPowerState;

   KeInitializeEvent(&gotoPowEvent, SynchronizationEvent, FALSE);

   status = PoRequestPowerIrp(PDevObj, IRP_MN_SET_POWER, powerState,
                              SerialSystemPowerCompletion, &gotoPowEvent,
                              NULL);

   if (status == STATUS_PENDING) {
      KeWaitForSingleObject(&gotoPowEvent, Executive, KernelMode, FALSE, NULL);
      status = STATUS_SUCCESS;
   }

#if DBG
   if (!NT_SUCCESS(status)) {
      SerialDump(SERPNPPOWER, ("SERIAL: SerialGotoPowerState FAILED\n"));
   }
#endif

   SerialDump(SERTRACECALLS, ("SERIAL: Leaving SerialGotoPowerState\n"));

   return status;
}




NTSTATUS
SerialSetPowerD3(IN PDEVICE_OBJECT PDevObj, IN PIRP PIrp)
/*++

Routine Description:

    This routine handles the SET_POWER minor function.

Arguments:

    PDevObj - Pointer to the device object for this device

    PIrp - Pointer to the IRP for the current request

Return Value:

    The function value is the final status of the call


--*/
{
   NTSTATUS status = STATUS_SUCCESS;
   PSERIAL_DEVICE_EXTENSION pDevExt = PDevObj->DeviceExtension;
   PIO_STACK_LOCATION pIrpStack = IoGetCurrentIrpStackLocation(PIrp);

   PAGED_CODE();

   SerialDump(SERDIAG3, ("SERIAL: In SerialSetPowerD3\n"));

   //
   // Send the wait wake now, just in time
   //


   if (pDevExt->SendWaitWake) {
      SerialSendWaitWake(pDevExt);
   }
   //
   // Before we power down, call PoSetPowerState
   //

   PoSetPowerState(PDevObj, pIrpStack->Parameters.Power.Type,
                   pIrpStack->Parameters.Power.State);

   //
   // If the device is not closed, disable interrupts and allow the fifo's
   // to flush.
   //

   if (pDevExt->DeviceIsOpened == TRUE) {
      LARGE_INTEGER charTime;

      pDevExt->DeviceIsOpened = FALSE;
      pDevExt->DeviceState.Reopen = TRUE;

      charTime.QuadPart = -SerialGetCharTime(pDevExt).QuadPart;

      //
      // Shut down the chip
      //

      SerialDisableUART(pDevExt);

      //
      // Drain the device
      //

      SerialDrainUART(pDevExt, &charTime);

      //
      // Save the device state
      //

      SerialSaveDeviceState(pDevExt);
   }

   //
   // If the device is not open, we don't need to save the state;
   // we can just reset the device on power-up
   //


   PIrp->IoStatus.Status = STATUS_SUCCESS;

   pDevExt->PowerState = PowerDeviceD3;

   //
   // For what we are doing, we don't need a completion routine
   // since we don't race on the power requests.
   //

   PIrp->IoStatus.Status = STATUS_SUCCESS;

   PoStartNextPowerIrp(PIrp);
   IoSkipCurrentIrpStackLocation(PIrp);

   return SerialPoCallDriver(pDevExt, pDevExt->LowerDeviceObject, PIrp);
}


NTSTATUS
SerialSendWaitWake(PSERIAL_DEVICE_EXTENSION PDevExt)
/*++

Routine Description:

    This routine causes a waitwake IRP to be sent

Arguments:

    PDevExt - Pointer to the device extension for this device

Return Value:

    STATUS_INVALID_DEVICE_STATE if one is already pending, else result
    of call to PoRequestPowerIrp.


--*/
{
   NTSTATUS status;
   PIRP pIrp;
   POWER_STATE powerState;

   PAGED_CODE();

   //
   // Make sure one isn't pending already -- serial will only handle one at
   // a time.
   //

   if (PDevExt->PendingWakeIrp != NULL) {
      return STATUS_INVALID_DEVICE_STATE;
   }

   //
   // Make sure we are capable of waking the machine
   //

   if (PDevExt->SystemWake <= PowerSystemWorking) {
      return STATUS_INVALID_DEVICE_STATE;
   }

   if (PDevExt->DeviceWake == PowerDeviceUnspecified) {
      return STATUS_INVALID_DEVICE_STATE;
   }

   //
   // Send IRP to request wait wake and add a pending irp flag
   //
   //

   InterlockedIncrement(&PDevExt->PendingIRPCnt);

   powerState.SystemState = PDevExt->SystemWake;

   status = PoRequestPowerIrp(PDevExt->Pdo, IRP_MN_WAIT_WAKE,
                              powerState, SerialWakeCompletion, PDevExt, &pIrp);

   if (status == STATUS_PENDING) {
      status = STATUS_SUCCESS;
      PDevExt->PendingWakeIrp = pIrp;
   } else if (!NT_SUCCESS(status)) {
      SerialIRPEpilogue(PDevExt);
   }

   return status;
}

NTSTATUS
SerialWakeCompletion(IN PDEVICE_OBJECT PDevObj, IN UCHAR MinorFunction,
                     IN POWER_STATE PowerState, IN PVOID Context,
                     IN PIO_STATUS_BLOCK IoStatus)
/*++

Routine Description:

    This routine handles completion of the waitwake IRP.

Arguments:

    PDevObj - Pointer to the device object for this device

    MinorFunction - Minor function previously supplied to PoRequestPowerIrp

    PowerState - PowerState previously supplied to PoRequestPowerIrp

    Context - a pointer to the device extension

    IoStatus - current/final status of the waitwake IRP

Return Value:

    The function value is the final status of attempting to process the
    waitwake.


--*/
{
   NTSTATUS status;
   PSERIAL_DEVICE_EXTENSION pDevExt = (PSERIAL_DEVICE_EXTENSION)Context;
   POWER_STATE powerState;

   status = IoStatus->Status;

   if (NT_SUCCESS(status)) {
      //
      // A wakeup has occurred -- powerup our stack
      //

      powerState.DeviceState = PowerDeviceD0;

      PoRequestPowerIrp(pDevExt->Pdo, IRP_MN_SET_POWER, powerState, NULL,
                        NULL, NULL);

   }

   pDevExt->PendingWakeIrp = NULL;
   SerialIRPEpilogue(pDevExt);

   return status;
}