如何编写Windows CE.net的usb驱动程序(2)

上述讲了堆理论，可能读者脑袋都已经大了，为此，我们举个简单的例子来详细说明一下驱动程序的开发过程。

例如我们有个USBMouse设备，设备信息描述如下：

DeviceDescriptor:

bcdUSB:0x0100

bDeviceClass:0x00

bDeviceSubClass:0x00

bDeviceProtocol:0x00

bMaxPacketSize0:0x08(8)

idVendor:0x05E3(GenesysLogicInc.)

idProduct:0x0001

bcdDevice:0x0101

iManufacturer:0x00

iProduct:0x01

iSerialNumber:0x00

bNumConfigurations:0x01

ConnectionStatus:DeviceConnected

CurrentConfigValue:0x01

DeviceBusSpeed:Low

DeviceAddress:0x02

OpenPipes:1

EndpointDescriptor:

bEndpointAddress:0x81

TransferType:Interrupt

wMaxPacketSize:0x0003(3)

bInterval:0x0A

可以看出上述设备有一个中断PIPE，包的最大值为3。可能有人问上述的值怎么得到的，win2k的DDK中有个usbview的例程，编译一下，将你的USB设备插到PC机的USB口中，运行usbview.exe即可看得相应的设备信息。

有了这些基本信息，就可以编写USB设备了，首先声明一下，下面的代码取自微软的USB鼠标样本程序，版权归微软所有，此处仅仅借用来描述一下USB鼠标驱动的开发过程，读者如需要引用此代码，需要得到微软的同意。

首先，必须输出USBD要求调用的三个函数，首先到设备插入到USB端口时，USBD会调用USBDeviceAttach()函数，相应的代码如下：

extern"C"BOOL

USBDeviceAttach(

USB_HANDLEhDevice,//USB设备句柄

LPCUSB_FUNCSlpUsbFuncs,//USBDI的函数集合

LPCUSB_INTERFACElpInterface,//设备接口描述信息

LPCWSTRszUniqueDriverId,//设备ID描述字符串。

LPBOOLfAcceptControl,//返回TRUE，标识我们可以控制此设备，反之表示不能控制

DWORDdwUnused)

{

*fAcceptControl=FALSE;

//我们的鼠标设备有特定的描述信息，要检测是否是我们的设备。

if(lpInterface==NULL)

returnFALSE;

//打印相关的USB设备接口描述信息。

DEBUGMSG(ZONE_INIT,(TEXT("USBMouse:DeviceAttach,IF%u,#EP:%u,Class:%u,Sub:%u,Prot:%urn"),lpInterface->Descriptor.bInterfaceNumber,lpInterface->Descriptor.bNumEndpoints,lpInterface->Descriptor.bInterfaceClass,lpInterface->Descriptor.bInterfaceSubClass,lpInterface->Descriptor.bInterfaceProtocol));

//初试数据USB鼠标类，产生一个接受USB鼠标数据的线程

CMouse*pMouse=newCMouse(hDevice,lpUsbFuncs,lpInterface);

if(pMouse==NULL)

returnFALSE;

if(!pMouse->Initialize())

{

deletepMouse;

returnFALSE;

}

//注册一个监控USB设备事件的回调函数，用于监控USB设备是否已经拔掉。

(*lpUsbFuncs->lpRegisterNotificationRoutine)(hDevice,

USBDeviceNotifications,pMouse);

*fAcceptControl=TRUE;

returnTRUE;

}

第二个函数是USBInstallDriver（）函数，

一些基本定义如下：

constWCHARgcszRegisterClientDriverId[]=L"RegisterClientDriverID";

constWCHARgcszRegisterClientSettings[]=L"RegisterClientSettings";

constWCHARgcszUnRegisterClientDriverId[]=L"UnRegisterClientDriverID";

constWCHARgcszUnRegisterClientSettings[]=L"UnRegisterClientSettings";

constWCHARgcszMouseDriverId[]=L"Generic_Sample_Mouse_Driver";

函数接口如下：

extern"C"BOOL

USBInstallDriver(

LPCWSTRszDriverLibFile)//@parm[IN]-ContainsclientdriverDLLname

{

BOOLfRet=FALSE;

HINSTANCEhInst=LoadLibrary(L"USBD.DLL");

//注册USB设备信息

if(hInst)

{

LPREGISTER_CLIENT_DRIVER_IDpRegisterId=(LPREGISTER_CLIENT_DRIVER_ID)

GetProcAddress(hInst,gcszRegisterClientDriverId);

LPREGISTER_CLIENT_SETTINGSpRegisterSettings=

(LPREGISTER_CLIENT_SETTINGS)GetProcAddress(hInst,

gcszRegisterClientSettings);

if(pRegisterId&&pRegisterSettings)

{

USB_DRIVER_SETTINGSDriverSettings;

DriverSettings.dwCount=sizeof(DriverSettings);

//设置我们的特定的信息。

DriverSettings.dwVendorId=USB_NO_INFO;

DriverSettings.dwProductId=USB_NO_INFO;

DriverSettings.dwReleaseNumber=USB_NO_INFO;

DriverSettings.dwDeviceClass=USB_NO_INFO;

DriverSettings.dwDeviceSubClass=USB_NO_INFO;

DriverSettings.dwDeviceProtocol=USB_NO_INFO;

DriverSettings.dwInterfaceClass=0x03;//HID

DriverSettings.dwInterfaceSubClass=0x01;//bootdevice

DriverSettings.dwInterfaceProtocol=0x02;//mouse

fRet=(*pRegisterId)(gcszMouseDriverId);

if(fRet)

{

fRet=(*pRegisterSettings)(szDriverLibFile,

gcszMouseDriverId,NULL,&DriverSettings);

if(!fRet)

{

//BUGBUGunregistertheClientDriver’sID

}

}

}

else

{

RETAILMSG(1,(TEXT("!USBMouse:ErrorgettingUSBDfunctionpointersrn")));

}

FreeLibrary(hInst);

}

returnfRet;

}

上述代码主要用于产生USB设备驱动程序需要的注册表信息，需要注意的是：USB设备驱动程序不使用标准的注册表函数，而是使用RegisterClientDriverID（）和RegisterClientSettings来注册相应的设备信息。[!--empirenews.page--]

另外一个函数是USBUninstallDriver()函数，具体代码如下：

extern"C"BOOL

USBUnInstallDriver()

{

BOOLfRet=FALSE;

HINSTANCEhInst=LoadLibrary(L"USBD.DLL");

if(hInst)

{

LPUN_REGISTER_CLIENT_DRIVER_IDpUnRegisterId=

(LPUN_REGISTER_CLIENT_DRIVER_ID)

GetProcAddress(hInst,gcszUnRegisterClientDriverId);

LPUN_REGISTER_CLIENT_SETTINGSpUnRegisterSettings=

(LPUN_REGISTER_CLIENT_SETTINGS)GetProcAddress(hInst,

gcszUnRegisterClientSettings);

if(pUnRegisterSettings)

{

USB_DRIVER_SETTINGSDriverSettings;

DriverSettings.dwCount=sizeof(DriverSettings);

//必须填入与注册时相同的信息。

DriverSettings.dwVendorId=USB_NO_INFO;

DriverSettings.dwProductId=USB_NO_INFO;

DriverSettings.dwReleaseNumber=USB_NO_INFO;

DriverSettings.dwDeviceClass=USB_NO_INFO;

DriverSettings.dwDeviceSubClass=USB_NO_INFO;

DriverSettings.dwDeviceProtocol=USB_NO_INFO;

DriverSettings.dwInterfaceClass=0x03;//HID

DriverSettings.dwInterfaceSubClass=0x01;//bootdevice

DriverSettings.dwInterfaceProtocol=0x02;//mouse

fRet=(*pUnRegisterSettings)(gcszMouseDriverId,NULL,

&DriverSettings);

}

if(pUnRegisterId)

{

BOOLfRetTemp=(*pUnRegisterId)(gcszMouseDriverId);

fRet=fRet?fRetTemp:fRet;

}

FreeLibrary(hInst);

}

returnfRet;

}

此函数主要用于删除USBInstallDriver()时创建的注册表信息，同样的它使用自己的函数接口UnRegisterClientDriverID（）和UnRegisterClientSettings（）来做相应的处理。

另外一个需要处理的注册的监控通知函数USBDeviceNotifications（）：

extern"C"BOOLUSBDeviceNotifications(LPVOIDlpvNotifyParameter,DWORDdwCode,

LPDWORD*dwInfo1,LPDWORD*dwInfo2,LPDWORD*dwInfo3,

LPDWORD*dwInfo4)

{

CMouse*pMouse=(CMouse*)lpvNotifyParameter;

switch(dwCode)

{

caseUSB_CLOSE_DEVICE:

//删除相关的资源。

deletepMouse;

returnTRUE;

}

returnFALSE;

}

USB鼠标的类的定义如下：

classCMouse

{

public:

CMouse::CMouse(USB_HANDLEhDevice,LPCUSB_FUNCSlpUsbFuncs,

LPCUSB_INTERFACElpInterface);

~CMouse();

BOOLInitialize();

private:

//传输完毕调用的回调函数

staticDWORDCALLBACKMouseTransferCompleteStub(LPVOIDlpvNotifyParameter);

//中断处理函数

staticULONGCALLBACKCMouse::MouseThreadStub(PVOIDcontext);

DWORDMouseTransferComplete();

DWORDMouseThread();

BOOLSubmitInterrupt();

BOOLHandleInterrupt();

BOOLm_fClosing;

BOOLm_fReadyForMouseEvents;

HANDLEm_hEvent;

HANDLEm_hThread;

USB_HANDLEm_hDevice;

USB_PIPEm_hInterruptPipe;

USB_TRANSFERm_hInterruptTransfer;

LPCUSB_FUNCSm_lpUsbFuncs;

LPCUSB_INTERFACEm_pInterface;

BOOLm_fPrevButton1;

BOOLm_fPrevButton2;

BOOLm_fPrevButton3;

//数据接受缓冲区。

BYTEm_pbDataBuffer[8];

};

具体实现如下：

//构造函数，初始化时调用

CMouse::CMouse(USB_HANDLEhDevice,LPCUSB_FUNCSlpUsbFuncs,

LPCUSB_INTERFACElpInterface)

{

m_fClosing=FALSE;

m_fReadyForMouseEvents=FALSE;

m_hEvent=NULL;

m_hThread=NULL;

m_hDevice=hDevice;

m_hInterruptPipe=NULL;

m_hInterruptTransfer=NULL;

m_lpUsbFuncs=lpUsbFuncs;

m_pInterface=lpInterface;

m_fPrevButton1=FALSE;

m_fPrevButton2=FALSE;

m_fPrevButton3=FALSE;

memset(m_pbDataBuffer,0,sizeof(m_pbDataBuffer));

}

//析构函数，用于清除申请的资源。

CMouse::~CMouse()

{

//通知系统去关闭相关的函数接口。

m_fClosing=TRUE;

//Wakeuptheconnectionthreadagainandgiveittimetodie.

if(m_hEvent!=NULL)

{

//通知关闭数据接受线程。

SetEvent(m_hEvent);

if(m_hThread!=NULL)

{

DWORDdwWaitReturn;

dwWaitReturn=WaitForSingleObject(m_hThread,1000);

if(dwWaitReturn!=WAIT_OBJECT_0)

{

TerminateThread(m_hThread,DWORD(-1));

}

CloseHandle(m_hThread);

m_hThread=NULL;

}

CloseHandle(m_hEvent);

m_hEvent=NULL;

}

if(m_hInterruptTransfer)

(*m_lpUsbFuncs->lpCloseTransfer)(m_hInterruptTransfer);

if(m_hInterruptPipe)

(*m_lpUsbFuncs->lpClosePipe)(m_hInterruptPipe);

}

//初始化USB鼠标驱动程序

BOOLCMouse::Initialize()

{

LPCUSB_DEVICElpDeviceInfo=(*m_lpUsbFuncs->lpGetDeviceInfo)(m_hDevice);

//检测配置：USB鼠标应该只有一个中断管道

if((m_pInterface->lpEndpoints[0].Descriptor.bmAttributes&USB_ENDPOINT_TYPE_MASK)!=USB_ENDPOINT_TYPE_INTERRUPT)

{

RETAILMSG(1,(TEXT("!USBMouse:EP0wrongtype(%u)!rn"),[!--empirenews.page--]

m_pInterface->lpEndpoints[0].Descriptor.bmAttributes));

returnFALSE;

}

DEBUGMSG(ZONE_INIT,(TEXT("USBMouse:EP0:MaxPacket:%u,Interval:%urn"),

m_pInterface->lpEndpoints[0].Descriptor.wMaxPacketSize,

m_pInterface->lpEndpoints[0].Descriptor.bInterval));

m_hInterruptPipe=(*m_lpUsbFuncs->lpOpenPipe)(m_hDevice,

&m_pInterface->lpEndpoints[0].Descriptor);

if(m_hInterruptPipe==NULL){

RETAILMSG(1,(TEXT("Mouse:Erroropeninginterruptpipern")));

return(FALSE);

}

m_hEvent=CreateEvent(NULL,FALSE,FALSE,NULL);

if(m_hEvent==NULL)

{

RETAILMSG(1,(TEXT("USBMouse:ErroronCreateEventforconnecteventrn")));

return(FALSE);

}

//创建数据接受线程

m_hThread=CreateThread(0,0,MouseThreadStub,this,0,NULL);

if(m_hThread==NULL)

{

RETAILMSG(1,(TEXT("USBMouse:ErroronCreateThreadrn")));

return(FALSE);

}

return(TRUE);

}

//从USB鼠标设备中读出数据，产生相应的鼠标事件。

BOOLCMouse::SubmitInterrupt()

{

if(m_hInterruptTransfer)

(*m_lpUsbFuncs->lpCloseTransfer)(m_hInterruptTransfer);

//从USB鼠标PIPE中读数据

m_hInterruptTransfer=(*m_lpUsbFuncs->lpIssueInterruptTransfer)

(m_hInterruptPipe,MouseTransferCompleteStub,this,

USB_IN_TRANSFER|USB_SHORT_TRANSFER_OK,//表示读数据

min(m_pInterface->lpEndpoints[0].Descriptor.wMaxPacketSize,

sizeof(m_pbDataBuffer)),

m_pbDataBuffer,

NULL);

if(m_hInterruptTransfer==NULL)

{

DEBUGMSG(ZONE_ERROR，（L"!USBMouse:ErrorinIssueInterruptTransferrn"));

returnFALSE;

}

else

{

DEBUGMSG(ZONE_TRANSFER,(L"USBMouse::SubmitInterrupt,Transfer:0x%Xrn",

m_hInterruptTransfer));

}

returnTRUE;

}

//处理鼠标中断传输的数据

BOOLCMouse::HandleInterrupt()

{

DWORDdwError;

DWORDdwBytes;

DWORDdwFlags=0;

INTdx=(signedchar)m_pbDataBuffer[1];

INTdy=(signedchar)m_pbDataBuffer[2];

BOOLfButton1=m_pbDataBuffer[0]&0x01?TRUE:FALSE;

BOOLfButton2=m_pbDataBuffer[0]&0x02?TRUE:FALSE;

BOOLfButton3=m_pbDataBuffer[0]&0x04?TRUE:FALSE;

if(!(*m_lpUsbFuncs->lpGetTransferStatus)(m_hInterruptTransfer,&dwBytes,&dwError))

{

DEBUGMSG(ZONE_ERROR,(TEXT("!USBMouse:ErrorinGetTransferStatus(0x%X)rn"),

m_hInterruptTransfer));

returnFALSE;

}

else

{

DEBUGMSG(ZONE_TRANSFER,(TEXT("USBMouse::HandleInterrupt,hTransfer0x%Xcomplete(%ubytes,Error:%X)rn"),

m_hInterruptTransfer,dwBytes,dwError));

}

if(!SubmitInterrupt())

returnFALSE;

if(dwError!=USB_NO_ERROR)

{

DEBUGMSG(ZONE_ERROR,(TEXT("!USBMouse:Error0x%Xininterrupttransferrn"),dwError));

returnTRUE;

}

if(dwBytes<3)

{

DEBUGMSG(ZONE_ERROR,(TEXT("!USBMouse:Invalidbytecnt%ufrominterrupttransferrn"),dwBytes));

returnTRUE;

}

if(dx||dy)

dwFlags|=MOUSEEVENTF_MOVE;

if(fButton1!=m_fPrevButton1)

{

if(fButton1)

dwFlags|=MOUSEEVENTF_LEFTDOWN;

else

dwFlags|=MOUSEEVENTF_LEFTUP;

}

if(fButton2!=m_fPrevButton2)

{

if(fButton2)

dwFlags|=MOUSEEVENTF_RIGHTDOWN;

else

dwFlags|=MOUSEEVENTF_RIGHTUP;

}

if(fButton3!=m_fPrevButton3)

{

if(fButton3)

dwFlags|=MOUSEEVENTF_MIDDLEDOWN;

else

dwFlags|=MOUSEEVENTF_MIDDLEUP;

}

m_fPrevButton1=fButton1;

m_fPrevButton2=fButton2;

m_fPrevButton3=fButton3;

DEBUGMSG(ZONE_EVENTS,

(TEXT("USBMouseevent:dx:%d,dy:%d,dwFlags:0x%X(B1:%u,B2:%u,B3:%u)rn"),

dx,dy,dwFlags,fButton1,fButton2,fButton3));

//通知系统产生鼠标事件

if(m_fReadyForMouseEvents)

mouse_event(dwFlags,dx,dy,0,0);

else

m_fReadyForMouseEvents=IsAPIReady(SH_WMGR);

returnTRUE;

}

DWORDCALLBACKCMouse::MouseTransferCompleteStub(LPVOIDlpvNotifyParameter)

{

CMouse*pMouse=(CMouse*)lpvNotifyParameter;

return(pMouse->MouseTransferComplete());

}

//数据传输完毕回调函数

DWORDCMouse::MouseTransferComplete()

{

if(m_hEvent)

SetEvent(m_hEvent);

return0;

}

ULONGCALLBACKCMouse::MouseThreadStub(PVOIDcontext)

{

CMouse*pMouse=(CMouse*)context;

return(pMouse->MouseThread());

}

//USB鼠标线程

DWORDCMouse::MouseThread()

{

DEBUGMSG(ZONE_INIT,(TEXT("USBMouse:Workerthreadstartedrn")));

SetThreadPriority(GetCurrentThread(),THREAD_PRIORITY_HIGHEST);[!--empirenews.page--]

if(SubmitInterrupt())

{

while(!m_fClosing)

{

WaitForSingleObject(m_hEvent,INFINITE);

if(m_fClosing)

break;

if((*m_lpUsbFuncs->lpIsTransferComplete)(m_hInterruptTransfer))

{

if(!HandleInterrupt())

break;

}

else

{

RETAILMSG(1,(TEXT("!USBMouse:Eventsignalled,buttransfernotcompletern")));

//Theonlytimethisshouldhappenisifwegetanerroronthetransfer

ASSERT(m_fClosing||(m_hInterruptTransfer==NULL));

break;

}

}

}

RETAILMSG(1,(TEXT("USBMouse:Workerthreadexitingrn")));

return(0);

}

看到了没有，其实USB的驱动程序编写就这么简单，类似的其他设备，例如打印机设备，就有BulkOUTPIPE，需要Bulk传输，那就需要了解一下IssueBulkTransfer（）的应用。当然如果是开发USBMassStorageDisk的驱动，那就需要了解更多的协议，例如Bulk-OnlyTransport协议等。

微软的WindowsCE.NET的PlatformBuild中已经带有USBPrinter和USBMassStorageDisk的驱动的源代码了，好好研究一下，你一定回受益非浅的。