ul_wdpnp.c

linux下的RS485的驱动 值得一看

    return STATUS_SUCCESS;
}

///////////////////////////////////////////////////////////////////////////////
//
// CanRemoveDevice
//
//      This routine determines if the device cab be safely removed.  In our case
//      we'll assume you can always remove the device.  A device might not be able to
//      be removed, for example, if it has opened handles or removing the device would
//      result in the lost of data.
//
//  INPUTS:
//
//      devExt  - Address of our device extension.
//      Irp         - Address of the input IRP.
//
//  OUTPUTS:
//
//      None.
//
//  RETURNS:
//
//    STATUS_SUCCESS;
//
//  IRQL:
//
//
//  NOTES:
//
//
///////////////////////////////////////////////////////////////////////////////
NTSTATUS CanRemoveDevice(PULAN_DEVICE_EXTENSION devExt, PIRP Irp)
{
    UNREFERENCED_PARAMETER(devExt);
    UNREFERENCED_PARAMETER(Irp);

    return STATUS_SUCCESS;
}

///////////////////////////////////////////////////////////////////////////////
//
// ReturnResources
//
//      This function is called to return any hardware resources which
//      have been allocated for the device.  In our case, these are
//      the Interrupt Object, and any ports we might have mapped through
//      memory.  Note that we do NOT return our Device Object here.
//
//  INPUTS:
//
//      devExt  - Address of our device extension.
//      Irp         - Address of the input IRP.
//
//  OUTPUTS:
//
//      None.
//
//  RETURNS:
//
//      VOID
//
//  IRQL:
//
//
//  NOTES:
//
//
///////////////////////////////////////////////////////////////////////////////
VOID
ReturnResources(PULAN_DEVICE_EXTENSION devExt)
{

    if (devExt->usb_bus && devExt->dev && devExt->fnc_cctrl) {
    	 //
    	 //Stop USB activity
    	 //
    	 	 
    	 devExt->fnc_cctrl(devExt,UL_CC_FREEIRQ,0);
	
	 usb_destroy_dev(((usb_device*)devExt->dev));
         devExt->dev=NULL;
    }

    //
    // Stop port activity
    //
    ul_drv_done_ext(devExt);
  
    //
    // Disconnect from any interrupts
    //
    if (devExt->InterruptObject) {

        //
        // Disconnect from the interrupt
        //
        IoDisconnectInterrupt(devExt->InterruptObject);

        devExt->InterruptObject = NULL;
    }

    KeCancelTimer(&devExt->wd_timer);
    KeRemoveQueueDpc(&devExt->wd_timer_dpc);
    KeRemoveQueueDpc(&devExt->bottom_dpc);

    //
    // Unmap any ports that were mapped
    //
    if (devExt->MappedPorts) {

        MmUnmapIoSpace((PVOID)devExt->port, DEF_PORT_RANGE);

        devExt->MappedPorts = FALSE;
        devExt->port = 0;
        
    }

}

///////////////////////////////////////////////////////////////////////////////
//
// RemoveDevice
//
//      This function is called ater ReturnResources to destroy and
//      remove uLan DeviceObject. Again resources must be already
//      returned before this call
//
//  INPUTS:
//
//      devExt  - Address of our device extension.
//
//  OUTPUTS:
//
//      None.
//
//  RETURNS:
//
//      VOID
//
//  IRQL:
//
//
//  NOTES:
//
//
///////////////////////////////////////////////////////////////////////////////
VOID RemoveDevice(IN PDEVICE_OBJECT devObj)
{
      PULAN_DEVICE_EXTENSION devExt;

      devExt=(PULAN_DEVICE_EXTENSION)devObj->DeviceExtension;

      //
      // Detach from the PDO 
      //
      if(devExt->DeviceToSendIrpsTo)
        IoDetachDevice(devExt->DeviceToSendIrpsTo);
      devExt->DeviceToSendIrpsTo = NULL;

      // Delete Symbolic Link
      if(devExt->link_name.Length&&devExt->link_name.Buffer)
        IoDeleteSymbolicLink(&devExt->link_name);
      if(devExt->link_name.Buffer)
	 	ExFreePool(devExt->link_name.Buffer);
      if(devExt->ntdev_name.Buffer)
	 	ExFreePool(devExt->ntdev_name.Buffer);

      // Destroy DeviceObject
      IoDeleteDevice(devObj);
}


///////////////////////////////////////////////////////////////////////////////
//
// RequestIncrement
// RequestDecrement
//
//      These functions are used to track the number of requests that
//      are presently queued the device indicated by the passed
//      Device Extension.
//
//      This code is based heavily on the PnP Sample Driver in the
//      \General directory of the NTDDK.
//
//  INPUTS:
//
//      devExt  - Address of our device extension.
//
//  OUTPUTS:
//
//      None.
//
//  RETURNS:
//
//    STATUS_SUCCESS;
//
//  IRQL:
//
//
//  NOTES:
//
//
///////////////////////////////////////////////////////////////////////////////
VOID
RequestIncrement(PULAN_DEVICE_EXTENSION devExt)
{

    LONG result;
    
    result = InterlockedIncrement(&devExt->OutstandingIO);

    ASSERT(result >= 0);
    
    //
    // Need to clear Remove
    //
    if (result == 1) {

        //
        // The remove event is cleared when the first request is
        // added to the queue.
        //
        KeClearEvent(&devExt->RemoveEvent);
    }

    return;
}

VOID
RequestDecrement(PULAN_DEVICE_EXTENSION devExt)
{

    LONG result;
    
    result = InterlockedDecrement(&devExt->OutstandingIO);
    
    ASSERT(result >= 0);

    if (result == 0) {

        //
        // The remove event is set when the queue is totally EMPTY.
        //
        KeSetEvent(&devExt->RemoveEvent, 
                   IO_NO_INCREMENT, 
                   FALSE);
        
    }

}

///////////////////////////////////////////////////////////////////////////////
//
// WaitForStop
//
//      Using the event set by the RequestIncrement() and 
//      RequestDecrement() functions, this function waits until
//      the device can be stopped.
//
//      On our device, STOP implies there are no active requests on
//      the device, even though there are queued requests.
//
//  INPUTS:
//
//      devExt  - Address of our device extension.
//
//  OUTPUTS:
//
//      None.
//
//  RETURNS:
//
//    STATUS_SUCCESS;
//
//  IRQL:
//
//
//  NOTES:
//
//
///////////////////////////////////////////////////////////////////////////////
VOID
WaitForStop(PULAN_DEVICE_EXTENSION devExt)
{

  #if 0 /* No need to wait for end of IO */

    devExt->HoldNewRequests = TRUE;

    ASSERT(devExt->State != STATE_STARTED);

    KeWaitForSingleObject(&devExt->StopEvent,
			   Executive,
                           KernelMode,
                           FALSE,
			   NULL);

  #endif
}

///////////////////////////////////////////////////////////////////////////////
//
// WaitForRemove
//
//      Using the event set by the RequestIncrement() and 
//      RequestDecrement() functions, this function waits until
//      the device can be removed.
//
//      On our device, REMOVE implies there are no active or queued
//      requests on the device.
//
//  INPUTS:
//
//      devExt  - Address of our device extension.
//
//  OUTPUTS:
//
//      None.
//
//  RETURNS:
//
//    STATUS_SUCCESS;
//
//  IRQL:
//
//
//  NOTES:
//
//
///////////////////////////////////////////////////////////////////////////////
VOID
WaitForRemove(PULAN_DEVICE_EXTENSION devExt)
{
#if DBG
    LARGE_INTEGER timeout;
    NTSTATUS status;

    timeout.QuadPart = -5*10*1000*1000;     // 5 seconds
#endif

    ///devExt->Removed = TRUE;

    ASSERT(devExt->State < STATE_ALL_BELOW_FAIL);

#if DBG

wait_again:

    status = KeWaitForSingleObject(&devExt->RemoveEvent,
                           Executive,
                           KernelMode,
                           FALSE,
                           &timeout);

    if(status == STATUS_TIMEOUT) {
    
        uLan_DbgPrint("uLan: *** Still Waiting for activity to stop on device??  %d. requests reamin\n", devExt->OutstandingIO);
        goto wait_again;
    }    

    if(status != STATUS_SUCCESS) {

        uLan_DbgPrint("uLan: *** Wait not ended with success, and not with timeout?? Status = 0x%0x\n", status);
    }

#else

    KeWaitForSingleObject(&devExt->RemoveEvent,
                           Executive,
                           KernelMode,
                           FALSE,
                           NULL);
#endif

}

///////////////////////////////////////////////////////////////////////////////
//
// DispatchSystemControl
//
//      This dispatch entry point is used to pass any WMI IRPs that we
//      receive on to the underlying bus driver.
//
//  INPUTS:
//
///     DriverObject - Pointer to driver object.
//      Irp         - Address of the input IRP.
//
//  OUTPUTS:
//
//      None.
//
//  RETURNS:
//
//      VOID
//
//  IRQL:
//
//
//  NOTES:
//
//
///////////////////////////////////////////////////////////////////////////////
NTSTATUS 
DispatchSystemControl(PDEVICE_OBJECT DeviceObject, PIRP Irp)
{

    //
    // Since we don't play WMI, pass this request on down to the
    // driver below us...
    //
    IoSkipCurrentIrpStackLocation(Irp);

    return(IoCallDriver(((PULAN_DEVICE_EXTENSION)(DeviceObject->DeviceExtension))->DeviceToSendIrpsTo, Irp));

}



VOID
PrintState(PULAN_DEVICE_EXTENSION devExt)
{
    if(devExt->State == STATE_REMOVED) {
        uLan_DbgPrint("uLan: STATE_REMOVED\n");
        return;
    }

    if(devExt->State == STATE_STARTED) {
        uLan_DbgPrint("uLan: STATE_STARTED\n");
        return;
    }

    if(devExt->State == STATE_REMOVE_PENDING) {
        uLan_DbgPrint("uLan: STATE_REMOVE_PENDING\n");
        return;
    }

    if(devExt->State == ST