usbview源码阅读与总结

一、所用接口总结
整个工程里，只用了如下几种与USB驱动相关的接口：
1、DeviceIoControl

HANDLE hHCDev = CreateFile("\\.\HCD0", , , , OPEN_EXISTING, 0, NULL);DeviceIoControl(hHCDev, IOCTL_USB_GET_xxx,,,struct, sizeof(struct),);CloseHandle(hHCDev);

它们定义在系统头文件<WinBase.h>中：
(c:\program files\microsoft sdks\windows\v7.0a\include)
(c:\winddk\7600.16385.1\inc\api)

2、CM_***

CM_Locate_DevNode(&devInst, NULL, 0)CM_Get_Child(&devInstNext, devInst, 0)CM_Get_Sibling(&devInstNext, devInst, 0)CM_Get_Parent(&devInstNext, devInst, 0)CM_Get_Device_ID(devInst, buf, len, 0);CM_Get_DevNode_Registry_Property(devInst,CM_DRP_DRIVER, NULL, buf, &len, 0);CM_Get_DevNode_Registry_Property(devInst, CM_DRP_DEVICEDESC, NULL, buf, &len, 0);

它们定义在系统头文件<CfgMgr32.h>中：
(c:\program files\microsoft sdks\windows\v7.0a\include)
(c:\winddk\7600.16385.1\inc\api)

3、SetupDi***

HDEVINFO hDevInfo = SetupDiGetClassDevs((LPGUID)&GUID_CLASS_USB_HOST_CONTROLLER,,,,);SetupDiEnumDeviceInterfaces(hDevInfo,,,,&devIntfData);SetupDiGetDeviceInterfaceDetail(hDevInfo, &devIntfData, devIntfDetailData,,);SetupDiDestroyDeviceInfoList(hDevInfo);

它们定义在系统头文件<SetupAPI.h>中：
(c:\program files\microsoft sdks\windows\v7.0a\include)
(c:\winddk\7600.16385.1\inc\api)

 

二、基本过程分析

EnumerateHostControllers()//主入口，枚举系统所有USB Host Controllerfor(i = 0; i < 10; i++){HANDLE hHCDev = CreateFile("\\.\HCD0", GENERIC_WRITE, FILE_SHARE_WRITE, NULL, OPEN_EXISTING, 0, NULL);EnumerateHostController(hHCDev)//枚举一个具体的USB Host ControllerUSB_HCD_DRIVERKEY_NAME  drvKeyName = {0};BOOL bRet = DeviceIoControl(hHCDev, IOCTL_GET_HCD_DRIVERKEY_NAME,,,drvKeyName, sizeof(drvKeyName),);drvKeyNameA: "{36FC9E60-C465-11CF-8056-444553540000}\0000"PTSTR deviceID/deviceDesc = DriverNameToDeviceDesc(drvKeyNameA, *);DEVINST devInst = 0;CONFIGRET cRet = CM_Locate_DevNode(&devInst, NULL, 0);cRet = CM_Get_Child(&devInstNext, devInst, 0); devInst = devInstNext;cRet = CM_Get_Sibling(&devInstNext, devInst, 0); devInst = devInstNext;cRet = CM_Get_Parent(&devInstNext, devInst, 0); devInst = devInstNext;cRet = CM_Get_DevNode_Registry_Property(devInst,CM_DRP_DRIVER, NULL, buf, &len, 0);buf: "{4D36E966-E325-11CE-BFC1-08002BE10318}\0000"cRet = CM_Get_Device_ID(devInst, buf, len, 0);buf: "PCI\VEN_8086&DEV_3B3C&SUBSYS_04401028&REV_06\3&11583659&0&D0"deviceID: bufcRet = CM_Get_DevNode_Registry_Property(devInst, CM_DRP_DEVICEDESC, NULL, buf, &len, 0);buf: "Intel(R) 5 Series/3400 Series Chipset Family USB Enhanced Host Controller - 3B3C"deviceDesc: bufUSB_ROOT_HUB_NAME rootHubName;BOOL bRet = DeviceIoControl(hHCDev, IOCTL_USB_GET_ROOT_HUB_NAME,,,rootHubName, sizeof(rootHubName),);rootHubNameA: "USB#ROOT_HUB20#4&8985dfa&0#{f18a0e88-c30c-11d0-8815-00a0c906bed8}"EnumerateHub(rootHubNameA)//获取一个具体的USB Hub的信息HANDLE hHubDevice =CreateFile("\\.\USB#ROOT_HUB20#4&8985dfa&0#{f18a0e88-c30c-11d0-8815-00a0c906bed8}",...);USB_HUB_CAPABILITIES_EX  hubCapsEx = {0};BOOL bRet = DeviceIoControl(hHubDevice, IOCTL_USB_GET_HUB_CAPABILITIES_EX,,,hubCapsEx, sizeof(hubCapsEx),);USB_HUB_CAPABILITIES  hubCaps = {0};BOOL bRet = DeviceIoControl(hHubDevice, IOCTL_USB_GET_HUB_CAPABILITIES,,,hubCaps, sizeof(hubCaps),);hubCaps.HubIs2xCapable: 1USB_NODE_INFORMATION  hubInfo = {0};BOOL bRet = DeviceIoControl(hHubDevice, IOCTL_USB_GET_NODE_INFORMATION,,,hubInfo, sizeof(hubInfo),);hubInfo.u.HubInformation.HubDescriptor.bNumberOfPorts: 2EnumerateHubPorts(hHubDevice, bNumberOfPorts)//枚举一个具体的USB Hub的所有端口for(index = 1; index <= bNumberOfPorts; index++){ USB_NODE_CONNECTION_INFORMATION_EX connInfoEx; = {0}; BOOL bRet = DeviceIoControl(hHubDevice, IOCTL_USB_GET_NODE_CONNECTION_INFORMATION_EX,,,connInfoEx, sizeof(connInfoEx),); USB_NODE_CONNECTION_INFORMATION connInfo; = {0}; BOOL bRet = DeviceIoControl(hHubDevice, IOCTL_USB_GET_NODE_CONNECTION_INFORMATION,,,connInfo, sizeof(connInfo),); connInfoEx.DeviceDescriptor  USB_NODE_CONNECTION_DRIVERKEY_NAME  drvKeyName = {0}; BOOL bRet = DeviceIoControl(hHubDevice, IOCTL_USB_GET_NODE_CONNECTION_DRIVERKEY_NAME,,,drvKeyName, sizeof(drvKeyName),); drvKeyNameA: "{36FC9E60-C465-11CF-8056-444553540000}\0005" PTSTR deviceDesc = DriverNameToDeviceDesc(drvKeyNameA, *); deviceDesc: "Generic USB Hub"  USB_DESCRIPTOR_REQUEST  configDescReq = {0}; BOOL bRet = DeviceIoControl(hHubDevice, IOCTL_USB_GET_DESCRIPTOR_FROM_NODE_CONNECTION,,,configDescReq, nBytes,);  if(connInfoEx.DeviceIsHub)//如果是USB Hub，递归调用EnumerateHub() USB_NODE_CONNECTION_NAME extHubName; BOOL bRet = DeviceIoControl(hHubDevice, IOCTL_USB_GET_NODE_CONNECTION_NAME,,,extHubName, sizeof(extHubName extHubNameA: "USB#Vid_8087&Pid_0020#5&2fd74a1d&0&1#{f18a0e88-c30c-11d0-8815-00a0c906bed8}"  EnumerateHub()//递归枚举一个具体的USB Hub HubInformation.HubDescriptor.bNumberOfPorts: 6  EnumerateHubPorts()//递归枚举一个具体的USB Hub的所有端口 for(index = 1; index <= bNumberOfPorts; index++) {  if(connInfoEx1.DeviceIsHub)//如果是USB Hub，递归调用EnumerateHub()  extHubNameA: "USB#Vid_0a5c&Pid_4500#6&2cd76888&0&1#{f18a0e88-c30c-11d0-8815-00a0c906bed8}  EnumerateHub()//获取一个具体的USB Hub的信息  HubInformation.HubDescriptor.bNumberOfPorts: 3  EnumerateHubPorts()//枚举一个具体的USB Hub的所有端口  for(index = 1; index <= bNumberOfPorts; index++)  {   //如果不是USB Hub，可能没连设备，或没配置   connInfoEx1.CurrentConfigurationValue: 0   connInfoEx2.CurrentConfigurationValue: 0   connInfoEx3.ConnectionStatus: NoDeviceConnected  }  connInfoEx2.ConnectionStatus: NoDeviceConnected  connInfoEx3.CurrentConfigurationValue: NoDeviceConnected  //如果有连设备，则获取设备的具体信息  connInfoEx4:   drvKeyNameA: "{53D29EF7-377C-4D14-864B-EB3A85769359}\0001"   deviceDesc: "Validity Sensor (VFS300)" }

三、疑点难点问题
1、如何获取设备描述符？
各种描述符都是用DeviceIoControl()接口获取的。
USB_NODE_INFORMATION里包含有USB_HUB_DESCRIPTOR；
USB_NODE_CONNECTION_INFORMATION里包含有USB_DEVICE_DESCRIPTOR。

2、如何获取接口描述符和端点描述符？
答：接口描述符和端点描述符，是紧跟在配置描述符后面的。
具体实现是在GetConfigDescriptor()里完成的，都保存在configDescReq中。

3、如何获取字符串描述符中的字符串是否支持国际化？
答：是的，获取字符串描述符时，可以指定LangID；
而LangNum和LangIDs在所有字符串描述符的起始位置（index=0），可以首先获取到。
LangIDs参见：http://www.usb.org/developers/docs/USB_LANGIDs.pdf