Windows驱动中USB获取端口状态

Windows驱动中USB获取端口状态

NTSTATUS HumGetPortStatus(IN PDEVICE_OBJECT DeviceObject, IN PULONG PortStatus)
{
    NTSTATUS ntStatus;
    PIRP irp;
    KEVENT event;
    IO_STATUS_BLOCK ioStatus;
    PIO_STACK_LOCATION nextStack;


    *PortStatus = 0;

    //
    // issue a synchronous request
    //

    KeInitializeEvent(&event, NotificationEvent, FALSE);

    irp = IoBuildDeviceIoControlRequest(
                IOCTL_INTERNAL_USB_GET_PORT_STATUS,
                GET_NEXT_DEVICE_OBJECT(DeviceObject),
                NULL,
                0,
                NULL,
                0,
                TRUE, /* INTERNAL */
                &event,
                &ioStatus);

    if (!irp) {
        return STATUS_INSUFFICIENT_RESOURCES;
    }
    //
    // Call the class driver to perform the operation.  If the returned status
    // is PENDING, wait for the request to complete.
    //

    nextStack = IoGetNextIrpStackLocation(irp);
    ASSERT(nextStack != NULL);

    nextStack->Parameters.Others.Argument1 = PortStatus;


    ntStatus = IoCallDriver(GET_NEXT_DEVICE_OBJECT(DeviceObject), irp);
    if (ntStatus == STATUS_PENDING) {
        ntStatus = KeWaitForSingleObject(
                       &event,
                       Suspended,
                       KernelMode,
                       FALSE,
                       NULL);
    } 
    else {
        ioStatus.Status = ntStatus;
    }


    //
    // USBD maps the error code for us
    //
    ntStatus = ioStatus.Status;

    return ntStatus;
}

#define  USBD_PORT_ENABLED      0x00000001
#define  USBD_PORT_CONNECTED    0x00000002