readwrite.cpp

一本在讲述USB驱动程式的书 及其范例原码

// Read/Write request processors for foo driver
// Copyright (C) 1999, 2000 by Walter Oney
// All rights reserved

#include "stddcls.h"
#include "driver.h"
#include "KmdResource.h"

NTSTATUS LoadFirmware(PDEVICE_EXTENSION pdx);

///////////////////////////////////////////////////////////////////////////////

#pragma PAGEDCODE

NTSTATUS DispatchCreate(PDEVICE_OBJECT fdo, PIRP Irp)
	{							// DispatchCreate
	PAGED_CODE();
	KdPrint((DRIVERNAME " - IRP_MJ_CREATE\n"));
	PDEVICE_EXTENSION pdx = (PDEVICE_EXTENSION) fdo->DeviceExtension;

	PIO_STACK_LOCATION stack = IoGetCurrentIrpStackLocation(Irp);

	NTSTATUS status = STATUS_SUCCESS;

	if (NT_SUCCESS(status))
		{						// okay to open
		if (InterlockedIncrement(&pdx->handles) == 1)
			{					// first open handle
			}					// okay to open
		}					// first open handle
	return CompleteRequest(Irp, status, 0);
	}							// DispatchCreate

///////////////////////////////////////////////////////////////////////////////

#pragma PAGEDCODE

NTSTATUS DispatchClose(PDEVICE_OBJECT fdo, PIRP Irp)
	{							// DispatchClose
	PAGED_CODE();
	KdPrint((DRIVERNAME " - IRP_MJ_CLOSE\n"));
	PDEVICE_EXTENSION pdx = (PDEVICE_EXTENSION) fdo->DeviceExtension;
	PIO_STACK_LOCATION stack = IoGetCurrentIrpStackLocation(Irp);
	if (InterlockedDecrement(&pdx->handles) == 0)
		{						// no more open handles
		}						// no more open handles

	return CompleteRequest(Irp, STATUS_SUCCESS, 0);
	}							// DispatchClose

///////////////////////////////////////////////////////////////////////////////
// This function illustrates how you could load locale-appropriate firmware
// from a resource in the driver file

#pragma PAGEDCODE

NTSTATUS LoadFirmware(PDEVICE_EXTENSION pdx)
	{							// LoadFirmware
	HANDLE hDriverResources;
	NTSTATUS status;

	// Open this driver file using the service key captured during DriverEntry

	status = OpenDriverResourcesFromRegistry(&servkey, &hDriverResources);
	if (!NT_SUCCESS(status))
		{
		KdPrint((DRIVERNAME " - Can't open driver file - %X\n", status));
		return status;
		}

	// Look for a firmware resource. Specify a neutral language id to get the
	// system locale by default. In this sample driver, the "firmware" is just
	// a localized string.

	ULONG size;
	PWCHAR firmware = (PWCHAR) FindResourceEx(hDriverResources, L"FIRMWARE", L"TheFirmware", 0, size);
	if (firmware)
		DbgPrint(DRIVERNAME " - TheFirmware is \"%ws\"\n", firmware);
	else
		KdPrint((DRIVERNAME " - No FIRMWARE resources\n"));

	CloseDriverResources(hDriverResources);

	return STATUS_SUCCESS;
	}							// LoadFirmware

///////////////////////////////////////////////////////////////////////////////

#pragma PAGEDCODE

NTSTATUS StartDevice(PDEVICE_OBJECT fdo, PCM_PARTIAL_RESOURCE_LIST raw, PCM_PARTIAL_RESOURCE_LIST translated)
	{							// StartDevice
	PDEVICE_EXTENSION pdx = (PDEVICE_EXTENSION) fdo->DeviceExtension;

	LoadFirmware(pdx);

	return STATUS_SUCCESS;
	}							// StartDevice

///////////////////////////////////////////////////////////////////////////////

#pragma PAGEDCODE

VOID StopDevice(IN PDEVICE_OBJECT fdo, BOOLEAN oktouch /* = FALSE */)
	{							// StopDevice
	PDEVICE_EXTENSION pdx = (PDEVICE_EXTENSION) fdo->DeviceExtension;
	}							// StopDevice