vxworks-usb-mouse-driver分析.doc

Vxworks usb mouse 驱动分析概述：最近在做嵌入式vxworks下usb触摸屏设计，参考了vxworks里面的usb mouse驱动的代码，分析了usb mouse驱动，根据自己的理解，写这个文档。如有任何问题请联系yxj_5421163.com，转载请标明出处。系统资源：Vxworks6.71、USB主机驱动栈模型原理 USB主机驱动栈模型下图所示： 1.1硬件层 在USB主机驱动栈的最底部是USB主控制器(USB HC，即USB Host Controller)。目前，USB主控制器可分为三类：通用型主控制器接口(UHCI)、开放型主控制器接口(OHCI)和增强型主控制接口和增强型主控制接口(EHCI)。其中，UHCI和OHCl支持USBl1低速接口，EHCl支持USB20高速接口。1.2主控制器驱动层对予每一类型的主控制器都有一个与硬件独立的USB主控制器驱动(Host Controller Driver，简称 HCD)。WindRiver提供了两个驱动：usbHedUheiLib (UHCI主控制器库)和usbHcdohciLib(OHCl主控制器库)。该模块向下直接与USB主控制器硬件进行交互操作，向上与USBD层的功能接口，提供各种功能函数的调用，支持对上层模块封装具体的HCD驱动的实现。1.3 USB核心驱动层USB核心驱动(USB host driver，简称USBD)模块实现USB的核心驱动，包括USB总线的枚举、总线带宽分配、传输控制等操作。该模块向下调用HCD接口模块，实现与HCD层的通信，将设备驱动的功能请求转化为相应功能模块的调用。USBD管理每一个与主机相连的USB设备，还负责自动处理USB电力管理和带宽管理及USB hub和设备的动态插拔。1.4 USB设备驱动层USB设备驱动层负责管理连接到USB上的不同类型的设备，它们依靠USBD来提供与每个设备的通信路径，主要实现USB设备的一些特定初始化工作，并将上层用户应用程序的请求转化为对相应的USBD驱动程序的调用。该层通过对应用层提供API函数，从而屏蔽USB实现的细节。1.5应用层应用层为用户编写的对USB设备进行读、写控制等指定功能的应用程序，应用层通过设备驱动程序和USB主机驱动程序完成指定的功能。2、USB mouse 驱动分析Usb mouse驱动属于设备驱动层，在vxworks里面，把usb mouse驱动设计成两层，即文件层+驱动层，文件层对上提供read、write、ioctl等接口，对下调用驱动层提供函数进行硬件初始化，对应的源代码是usrUsbMseInit.c (targetconfigcompssrc)。驱动层则针对具体usb设备初始化，获取数据等。2.1 文件层usrUsbMseInit.c分析在usrRoot （usrConfig.c (targetconfigall)）调用#ifdef INCLUDE_USB_MOUSE_INIT usrUsbMseInit (); /* Mouse Driver Initialization */#endifusrUsbMseInit （usrUsbMseInit.c (targetconfigcompssrc)）驱动程序入口点，首先检查driver是否已经安装，如果安装就退出if (usbMseDrvNum 0)printf (Mouse already initilaized.n); return ERROR;接着调用usbMseDrvNum = iosDrvInstall (FUNCPTR) NULL, (FUNCPTR) usbMseDevDelete, (FUNCPTR) usbMseOpen, (FUNCPTR) usbMseClose, (FUNCPTR) usbMseRead, (FUNCPTR) usbMseWrite, (FUNCPTR) usbMseIoctl);安装驱动的I/O函数，添加驱动到驱动表里面接着调用驱动层初始化函数if (usbMouseDevInit () = OK) usbMouseLib.c (targetsrcdrvusb) printf (usbMouseDevInit() returned OKn);这个函数如果成功，会输出打印上面的信息表明驱动已经加载，并且和usb设备已经匹配上。接着调用驱动层动态注册函数if (usbMouseDynamicAttachRegister (usbMseDrvAttachCallback, (void *) NULL) != OK) usbMouseLib.c (targetsrcdrvusb)这个函数会把usbMseDrvAttachCallback保存在驱动层创建的一个队列里面，当usb设备热插拔时，都会调用这个函数。如果已经插入了usb mouse，就会马上调用usbMseDrvAttachCallback，参数为USB_MSE_ATTACH， 如果没有插入，那么驱动加载已经完成了。看usbMseDrvAttachCallback （usrUsbMseInit.c (targetconfigcompssrc)）因为第一次参数是USB_MSE_ATTACH，就会进入if (attachCode = USB_MSE_ATTACH)这个分支：首先调用驱动层的if (usbMouseSioChanLock (pChan) != OK)，标记SIO_CHAN structure已经在使用接着调用sprintf (mseName, %s%d, USB_MSE_NAME, mseCount); if (usbMseDevCreate (mseName, pChan) != OK)创建设备文件，即创建/usbMo/X，X由mseCount决定，同时创建文件层设备结构，并放在链表里面，调用iosDevAdd将设备添加到系统设备列表里面接着调用if (usbMseDevFind (pChan, &pUsbMseDev) != OK)printf(usbMseDevFind() returned ERRORn);return;根据pchan在链表里面找到这个usb设备的文件层设备结构接着调用if (*pChan-pDrvFuncs-callbackInstall) (pChan, SIO_CALLBACK_PUT_MOUSE_REPORT,(STATUS (*) (void *, .) usbMseRptCallback, (void *) pUsbMseDev) != OK)pChan-pDrvFuncs-callbackInstall是usbMouseLib.c里面的usbMouseCallbackInstall函数，它安装回调函数，当usb接受到数据后就会调用usbMseRptCallback这个函数。如果上面都执行成功，会输出打印下面信息printf(USB Mouse attached as %sn, mseName);至此，驱动加载完成，并且设备文件也已经创建好了。2.2 驱动层usbMouseLib.c分析在文件层usrUsbMseInit会调用usbMouseDevInit-驱动层初始化入口if (initCount = 0) 表明还没有进行初始化，初始化内部结构体，并链接在usbd上if (usbdClientRegister (MSE_CLIENT_NAME, &usbdHandle) != OK |usbdDynamicAttachRegister (usbdHandle, USB_CLASS_HID,USB_SUBCLASS_HID_BOOT, USB_PROTOCOL_HID_BOOT_MOUSE,FALSE,usbMouseAttachCallback) != OK)return doShutdown (S_usbMouseLib_USBD_FAULT);usbdClientRegister （usbTransUnitInit.c (targetsrcusb)）生成usb设备驱动的usbdHandleif ( !usbtuInitCount) /* usbdInitialize() not called */ USBTU_LOG(usbdClientRegister returns ERROR:usbdInitialize not calledn); return ERROR; 检查usbd是否初始化了，如果没有就出错退出。/* allocate structure for client */ if ( !(pDriver = OSS_CALLOC ( sizeof (USBTU_DEVICE_DRIVER) USBTU_LOG ( usbdClientRegister returns ERROR : malloc failed n); return ERROR; 创建client driver结构体if (pClientHandle != NULL) *pClientHandle = pDriver;将client driver赋给usbdHandle usbdDynamicAttachRegister （usbTransUnitInit.c (targetsrcusb)）填充usb设备驱动的usbdHandle，并且注册usbMouseAttachCallback函数，当有热插拔发生时，会调用这个函数，并且将usb设备client注册到usbd上。这三个参数USB_CLASS_HID，USB_SUBCLASS_HID_BOOT, USB_PROTOCOL_HID_BOOT_MOUSE是类代码、子类代码和协议代码，会被填充在usbdHandle上，后面usb驱动就会根据这三个参数把驱动和相应的设备联系起来。pDriverData-bFlagVendorSpecific = vendorSpecific; pDriverData-uVendorIDorClass = deviceClass; pDriverData-uProductIDorSubClass = deviceSubClass;pDriverData-uBCDUSBorProtocol = deviceProtocol;pDriverData-addDevice = usbtuInitDeviceAdd;pDriverData-removeDevice = usbtuInitDeviceRemove;pDriverData-suspendDevice = usbtuInitDeviceSuspend;pDriverData-resumeDevice = usbtuInitDeviceResume;我在网上看到好多人不想用这三个参数来识别usb硬件设备，想用vid和pid来设备，那也可以，秘密就在bFlagVendorSpecific这个标志上，上面函数调用时传入的vendorSpecific参数为false，意思就是不用vid和pid，如果传入是TRUE，就是要用vid和pid来识别，看看uVendorIDorClass和uProductIDorSubClass名字就知道意思了，可能是vid或者类代码，另一个可能是pid或者子类代码，都是由bFlagVendorSpecific决定接着调用usbHstDriverRegister （Usbd.c (targetsrchwifusb)）将usb设备client注册到usbd上if (NULL = pDeviceDriverInfo) | (NULL = pDeviceDriverInfo-addDevice) | (NULL = pDeviceDriverInfo-removeDevice) | (NULL = pDeviceDriverInfo-resumeDevice) | (NULL = pDeviceDriverInfo-suspendDevice) OS_LOG_MESSAGE_MEDIUM( USBD, usbHstRegisterDriver() Failed: Invalid parameter Driver info.n, 0, 0, 0, 0); return USBHST_INVALID_PARAMETER; 判断pDeviceDriverInfo里面一些处理函数是否存在，如果没有就出错返回，从上面看到调用这个函数的函数已经把这些变量赋值了。下面是一段处理usb hub的代码，就不分析了/* Store the global driver list in pOldDriverList*/ pOldDriverList = gpDeviceDriverList; while (NULL != pOldDriverList) /* * Check if the bFlagVendorSpecific, VendorIDorClass, * uProductIDorSubClass are same. */ if (pOldDriverList-pDriver-bFlagVendorSpecific = pDeviceDriverInfo-bFlagVendorSpecific) & (pOldDriverList-pDriver-uVendorIDorClass = pDeviceDriverInfo-uVendorIDorClass) & (pOldDriverList-pDriver-uProductIDorSubClass = pDeviceDriverInfo-uProductIDorSubClass) & (pOldDriverList-pDriver-uBCDUSBorProtocol = pDeviceDriverInfo-uBCDUSBorProtocol) OS_LOG_MESSAGE_HIGH( USBD, usbHstRegisterDriver() Failed: Driver is already registered.n, 0, 0, 0, 0); return USBHST_FAILURE; /* Get the driver in the list */ pOldDriverList = pOldDriverList-pNextDriver; 遍历整个gpDeviceDriverList 链表，检查pDeviceDriverInfo是否已经存在，如果存在就错误返回。pNewDriverList = (pUSBD_DEVICE_DRIVER_LIST)OS_MALLOC(sizeof(USBD_DEVICE_DRIVER_LIST);如果不存在，新创建一个pNewDriverListpNewDriverList-pDriver = pDeviceDriverInfo;将pDeviceDriverInfo放在pNewDriverList里面/* make pVxbDriverInfo point to the pDeviceDriverInfo : vxbDriverInfo */ pVxbDriverInfo = &(pDeviceDriverInfo-vxbDriverInfo); memset (pVxbDriverInfo, 0, sizeof (DRIVER_REGISTRATION); /* populate struct vxbDevRegInfo. The devId should be VXB_DEVID_BUSCTRL for * hub driver and VXB_DEVID_DEVICE for all other class drivers. * The vxbDevRegInfo : drvName should be determined for the class code */ /* parent bus ID. Should always be hub bus type. */ pVxbDriverInfo-busID = VXB_BUSID_USB_HUB; if (USBHST_HUB_CLASS = pDeviceDriverInfo-uVendorIDorClass) pVxbDriverInfo-devID = VXB_DEVID_BUSCTRL; else pVxbDriverInfo-devID = VXB_DEVID_DEVICE; /* version number */ pVxbDriverInfo-vxbVersion = VXB_VER_4_0_0; /* driver name. The name of the driver should not be greater than * MAX_DRV_NAME_LEN */ for (size = 0; pDrvNamesize!= 0; size+) pVxbDriverInfo-drvNamesize = pDrvNamesize; pVxbDriverInfo-drvNamesize = 0; /* function pointer to add device */ pVxbDriverInfo-pDrvBusFuncs = &usbVxbDeviceDriverInitFuncs; /* methods */pVxbDriverInfo-pMethods = &usbVxbDeviceDriverMethods0;填充pVxbDriverInfo/* register the driver with vxBus */ if (vxbDevRegister (pVxbDriverInfo) = ERROR) OS_LOG_MESSAGE_HIGH( USBD, usbHstRegisterDriver() Failed: vxBus Registration failedn,0,0, 0,0); /* free allocated memory */ OS_FREE (pNewDriverList); return USBHST_FAILURE; 调用vxbDevRegister将usb驱动注册在vxBus上pNewDriverList-pNextDriver = gpDeviceDriverList; /* Assign the new driver to global driver list */ gpDeviceDriverList = pNewDriverList;将pNewDriverList放在gpDeviceDriverList链表的头部。至此usbdDynamicAttachRegister执行完成，返回到usbMouseDevInit里面，这个函数也执行完成。驱动加载完成。再看vxbDevRegister（vxBus.c (targetsrchwifvxbus)）函数调用if ( vxbDrvVerCheck(pDevInfo) != OK ) return(ERROR);先检查vxbus drv版本，vxbus drv版本上面填充VXB_VER_4_0_0pListEnd-pNext = pDriverListHead; pDriverListHead = pDevInfo;将pDevInfo放在链表头部/* Check existing devices, to see if this driver matches */ pCurrent = pDevInfo; while ( pCurrent != pListEnd ) VXB_DEBUG_MSG(2,vxbDevRegister() checking for orphans on %sn, (int)vxbBusTypeString(pCurrent-busID), 2,3,4,5,6); vxbDevIterate(vxbNewDriver, pCurrent, VXB_ITERATE_ORPHANS); pCurrent = pCurrent-pNext; 这里就检查存在的usb device，看看这个驱动是否匹配。看vxbDevIterate函数pBusPres = pPlbBus; /* start with PLB controller */ (*func)(pBusPres-pCtlr, pArg);Func就是vxbNewDriver，pArg就是上面的pDevInfo，而pBusPres-pCtlr就是vxbus上usb设备的信息结构体看vxbNewDriver函数先检查dev和drv一些相关的变量/* get bus type of current device */ pBusEntry = pDev-pParentBus-pBusType; /* check bus-specific match routine */ drvFound = (*(pBusEntry-vxbDevMatch)(pDriver, pDev); if ( drvFound = FALSE ) return(ERROR);调用vxbus上的dev匹配函数去匹配dev和drv，vxbDevMatch 这个是vxbus注册时用usbVxbRegHubBusType结构体填充的，这个函数就是usbdFindDriver，如果匹配不成功，就停止匹配，驱动返回。看usbdFindDriver函数pUSBD_DEVICE_INFO pUSBDeviceInfo = (pUSBD_DEVICE_INFO) pDev-pBusSpecificDevInfo; /* extract the device information from vxBus */ /* device information */ pUSBHST_DEVICE_DRIVER pDriverInfo = (pUSBHST_DEVICE_DRIVER)pDriver;得到pUSBD_DEVICE_INFO结构体，这是usb设备信息，这个结构体在usbHstDeviceNew里面创建，并且赋值。/* * Check if the device has multiple configurations and is vendor * specific. If so, return error */ if (1 uNumConfigurations) & (USBHST_VENDOR_SPECIFIC = pUSBDeviceInfo-uDeviceClass) OS_LOG_MESSAGE_HIGH( USBD, usbdFindDriver() Failed: Vendor specific device with multiple configurations not supported.n, 0, 0, 0, 0); return FALSE; 检查如果这个设备有多个配置，但是又指明vid，这是不支持的，出错返回。if (USBHST_VENDOR_SPECIFIC = pUSBDeviceInfo-uDeviceClass) if (0 = pUSBDeviceInfo-uVendorID) OS_LOG_MESSAGE_MEDIUM( USBD, usbdFindDriver() Failed: Invalid parameter Device Info.n, 0, 0, 0, 0); return FALSE; /* Find the matching driver for the device */ if (usbdMatchDriver (TRUE, pUSBDeviceInfo-uVendorID, pUSBDeviceInfo-uDeviceID, pUSBDeviceInfo-uBCDDevice, pDriverInfo) = TRUE) /* Store the driver info in the device info*/ pUSBDeviceInfo-pDriver = pDriverInfo; return TRUE; if (0 != pUSBDeviceInfo-uDeviceClass) /* Find the matching driver for the device */ if (usbdMatchDriver (FALSE, pUSBDeviceInfo-uDeviceClass, pUSBDeviceInfo-uDeviceSubClass, pUSBDeviceInfo-uDeviceProtocol, pDriverInfo) = TRUE) /* Store the driver info in the device info*/ pUSBDeviceInfo-pDriver = pDriverInfo; return TRUE; 如果usb 设备类代码是0xff，就必须有vid，如果vid为0，出错返回，如果不为0，调用usbdMatchDriver用设备的vid和pid去匹配driver，driver也得提供vid和pid，如果类代码不是0xff，也不为0，调用usbdMatchDriver用设备的类代码和子类代码，协议代码去匹配driver，driver也得提供相应的代码，如果类代码等于0，接着判断interface描述符的类代码是否为0xff，如果是0xff，调用usbdMatchDriver用设备的vid和pid去匹配driver，driver也得提供vid和pid，如果不是0xff，调用usbdMatchDriver用设备的类代码和子类代码，协议代码去匹配driver，driver也得提供相应的代码。前面讲到有网友不想用类代码来进行设备和驱动的匹配，那就要满足两个条件：usb硬件满足类代码为0xff，vid不为0，或者类代码为0，接口描述符类代码为0xff，vid不为0usb驱动调用usbdDynamicAttachRegister时，第五个参数为true，第二个参数为usb硬件的vid，第三个参数为usb硬件的pid看usbdMatchDriver这个函数就是根据dev和drv的类代码或者id进行匹配，如果匹配成功，就返回true，同时把drv结构体放在pUSBDeviceInfo-pDriver或者pInterfaceInfo-pDriver里面。if ( pDriver-devProbe = NULL ) drvFound = TRUE; else drvFound = (*(pDriver-devProbe)(pDev); if ( drvFound = FALSE ) return(ERROR); 执行drv的probe函数，这也是个空函数/* attach driver */ pDev-pDriver = pDriver; /* adjust name */ pDev-pName = &pDriver-drvName0;把drv赋给dev/* perform initialization */ vxbDevInitRun(pDev, pDriver);执行usb dev的初始化看vxbDevInitRun函数/* first pass */ if (!(devID-flags & VXB_INST_INIT_DONE) if ( pDrv-pDrvBusFuncs-devInstanceInit != NULL ) (*(pDrv-pDrvBusFuncs-devInstanceInit)(devID); devID-flags |= VXB_INST_INIT_DONE; /* second pass */ if (vxbInitPhase = 2 & !(devID-flags & VXB_INST_INIT2_DONE) if ( pDrv-pDrvBusFuncs-devInstanceInit2 != NULL ) (*(pDrv-pDrvBusFuncs-devInstanceInit2)(devID); devID-flags |= VXB_INST_INIT2_DONE; /* third pass */ if (vxbInitPhase = 3 & !(devID-flags & VXB_INST_CONNECT_DONE) if ( pDrv-pDrvBusFuncs-devInstanceConnect != NULL ) (*(pDrv-pDrvBusFuncs-devInstanceConnect)(devID); devID-flags |= VXB_INST_CONNECT_DONE; 分三个阶段初始化，我们只看第三阶段链接，pDrv-pDrvBusFuncs-devInstanceConnect，这个pDrv就是usbHstDriverRegister函数传进去的pVxbDriverInfo，在这个函数里面有pVxbDriverInfo-pDrvBusFuncs = &usbVxbDeviceDriverInitFuncs;LOCAL DRIVER_INITIALIZATION usbVxbDeviceDriverInitFuncs = usbVxbDeviceDriverInstInit, /* init 1 */ usbVxbNullFunction, /* init 2 */ usbVxbDeviceAdd /* device connect */ ;因此pDrv-pDrvBusFuncs-devInstanceConnect就是调用usbVxbDeviceAdd函数，参数是dev，即usb设备信息看usbVxbDeviceAdd函数pUSBD_DEVICE_INFO pDeviceInfo = (pUSBD_DEVICE_INFO)pDevInfo-pBusSpecificDevInfo; /* call the addDevice routine for the device */ if (pDeviceInfo-pDriver != NULL) status = pDeviceInfo-pDriver-addDevice (pDeviceInfo-hDevice, 0, pDeviceInfo-uDeviceSpeed, &(pDeviceInfo-pDriverData) );这个pDeviceInfo-pDriver就是在函数usbdFindDriver里面pDriverInfo，也就是函数usbdDynamicAttachRegister里面pDriverData这个结构体。因此pDeviceInfo-pDriver-addDevice就是usbtuInitDeviceAdd函数看usbtuInitDeviceAdd函数/* initialize message structure */ tuMessage.eventCode = ADDDEVICE; tuMessage.hDevice = hDevice; tuMerface = interfaceNumber; tuMessage.ppDriverData = ppDriverData; /* handle the message event */ usbtuInitHandleDeviceEvent(&tuMessage);发送usb设备add的消息看usbtuInitHandleDeviceEvent函数在case ADDDEVICE:分支里面，得到usb设备的设备描述符和interface描述符，调用pDriver = usbtuInitFindDriverInfo(pDevDescr, pIfDescr, &vendorOrClass , &deviceOrSubclass, &bcdOrProtocol );通过类代码或者id在usbtuClientList寻找符合的pDriver，如果找到，创建新的pNodeInfo结构体，接着创建client的message并发送/* initialize message structure */ clientMessage.eventCode = ADDDEVICE; clientMessage.hDevice = pMessage-hDevice; clientMerface = pMessage-interface; clientMessage.class = vendorOrClass; clientMessage.subclass = deviceOrSubclass; clientMtocol = bcdOrProtocol;/* send the message to client thread */ usbtuInitHandleClientEvent (pDriver, &clientMessage);看usbtuInitHandleClientEvent函数在case ADDDEVICE:分支里面/* call the user supplied callback */ (*pDriver-attachCallback) ( (USBD_NODE_ID) pClientMessage-hDevic