HDF（Hardware Driver Foundation）驅動框架是HarmonyOS硬件生態開放的基礎，為開發者提供了驅動加載、驅動服務管理和驅動消息機制等驅動能力，讓開發者能精準且高效的開發驅動程序。本期，我們將為大家帶來HDF驅動框架中USB DDK的解析與指導。

1USB Host DDK

2USB Device DDK

USB Device DDK給開發者提供了設備端USB驅動開發能力。例如，USB端口動態注冊和去注冊能力，開發者可以基于能力實現USB端口的動態添加和組合；動態實例化能力，支持根據動態下發設備、配置、接口及端點描述符創建設備實例及傳輸通道；用戶態的數據發送及接收能力，支持用戶態下發送及接收數據；復合設備能力，支持一個物理設備上多個邏輯設備，實現多個邏輯設備間隔離，并支持不同邏輯設備同時被不同的應用進程訪問。

USB Device DDK架構如圖2所示：

二、USB DDK開發指導

1USB Host的開發

USB Host（主機端驅動）主要完成協議封裝、設備管理、驅動安裝與卸載等。通過上文的介紹，開發者可通過USB DDK API和USB RAW API來實現主機端驅動。

圖3 USB DDK API部分接口

(1) 配置驅動匹配表，完成主機端驅動總體信息的配置，具體如下：

struct UsbPnpMatchIdTable {//驅動模塊名，該字段的值必須和驅動入口結構的moduleName一致const char *moduleName;//驅動對外發布服務的名稱，必須唯一const char *serviceName;//驅動私有數據匹配關鍵字const char *deviceMatchAttr;//從該字段開始（包含該字段）之后數據長度，以byte為單位uint8_t length;//USB驅動匹配規則uint16_t matchFlag;//廠商編號uint16_t vendorId;//產品編號uint16_t productId;//設備出廠編號，低16位uint16_t bcdDeviceLow;//設備出廠編號，高16位uint16_t bcdDeviceHigh;  //USB分配的設備類代碼uint8_t deviceClass;//USB分配的子類代碼uint8_t deviceSubClass;//USB分配的設備協議代碼uint8_t deviceProtocol;//接口類型，根據實際需要可填寫多個uint8_t interfaceClass[USB_PNP_INFO_MAX_INTERFACES];//接口子類型，根據實際需要可填寫多個uint8_t interfaceSubClass[USB_PNP_INFO_MAX_INTERFACES];//接口所遵循的協議，根據實際需要可填寫多個uint8_t interfaceProtocol[USB_PNP_INFO_MAX_INTERFACES];//接口的編號，根據實際需要可填寫多個uint8_t interfaceNumber[USB_PNP_INFO_MAX_INTERFACES];};

enum {    USB_PNP_NOTIFY_MATCH_VENDOR = 0x0001,    USB_PNP_NOTIFY_MATCH_PRODUCT = 0x0002,    USB_PNP_NOTIFY_MATCH_DEV_LOW = 0x0004,    USB_PNP_NOTIFY_MATCH_DEV_HIGH = 0x0008,    USB_PNP_NOTIFY_MATCH_DEV_CLASS = 0x0010,    USB_PNP_NOTIFY_MATCH_DEV_SUBCLASS = 0x0020,    USB_PNP_NOTIFY_MATCH_DEV_PROTOCOL = 0x0040,    USB_PNP_NOTIFY_MATCH_INT_CLASS = 0x0080,    USB_PNP_NOTIFY_MATCH_INT_SUBCLASS = 0x0100,    USB_PNP_NOTIFY_MATCH_INT_PROTOCOL = 0x0200,    USB_PNP_NOTIFY_MATCH_INT_NUMBER = 0x0400,};

int32_t UsbInitHostSdk(struct UsbSession **session)

const struct UsbInterface *UsbClaimInterface(const struct UsbSession *session, uint8_t busNum, uint8_t usbAddr, uint8_t interfaceIndex);

UsbInterfaceHandle *UsbOpenInterface(const struct UsbInterface *interfaceObj);

int32_t UsbGetPipeInfo(const UsbInterfaceHandle *interfaceHandle, uint8_t settingIndex, uint8_t pipeId, struct UsbPipeInfo *pipeInfo);

struct UsbRequest *UsbAllocRequest(const UsbInterfaceHandle *interfaceHandle, int isoPackets, int length);

int32_t UsbFillRequest(const struct UsbRequest *request, const UsbInterfaceHandle *interfaceHandle, const struct UsbRequestParams *params);

int32_t UsbSubmitRequestSync(const struct UsbRequest *request);//發送同步IO請求int32_t UsbSubmitRequestAsync(const struct UsbRequest *request);//發送異步IO請求

USB RAW API主要實現USB更加復雜的功能，如獲取描述符信息、獲取設備指針、復位設備、提交傳輸請求等，如圖4所示，是USB RAW API提供的部分接口。

(1) 同USB DDK API的步驟1一樣，需先進行驅動匹配表配置。

int32_t UsbRawInit(struct UsbSession **session);

UsbRawHandle *UsbRawOpenDevice(const struct UsbSession *session, uint8_t busNum, uint8_t usbAddr);

int32_t UsbRawGetConfigDescriptor(const UsbRawDevice *rawDev, uint8_t configIndex, struct UsbRawConfigDescriptor **config);

int32_t UsbRawFillBulkRequest(const struct UsbRawRequest *request, const UsbRawHandle *devHandle, const struct UsbRawFillRequestData *fillData);// 填充用于批量傳輸的請求int32_t UsbRawFillControlSetup(const unsigned char *setup, const struct UsbControlRequestData *requestData);int32_t UsbRawFillControlRequest(const struct UsbRawRequest *request, const UsbRawHandle *devHandle, const struct UsbRawFillRequestData *fillData);// 填充用于控制傳輸的請求int32_t UsbRawFillInterruptRequest(const struct UsbRawRequest *request, const UsbRawHandle *devHandle, const struct UsbRawFillRequestData *fillData);// 填充用于中斷傳輸的請求int32_t UsbRawFillIsoRequest(const struct UsbRawRequest *request, const UsbRawHandle *devHandle, const struct UsbRawFillRequestData *fillData);// 填充用于同步傳輸的請求

int32_t UsbRawSendControlRequest(const struct UsbRawRequest *request, const UsbRawHandle *devHandle, const struct UsbControlRequestData *requestData);//發送同步USB控制傳輸請求int32_t UsbRawSendBulkRequest(const struct UsbRawRequest *request, const UsbRawHandle *devHandle, const struct UsbRequestData *requestData);//發送同步USB批量傳輸請求int32_t UsbRawSendInterruptRequest(const struct UsbRawRequest *request, const UsbRawHandle *devHandle, const struct UsbRequestData *requestData);//發送同步執行USB中斷傳輸請求int32_t UsbRawSubmitRequest(const struct UsbRawRequest *request);//提交異步IO請求

2USB Device的開發

USB Device（設備端驅動）主要實現設備管理、配置管理、IO管理、數據通信等。USB Deivce DDK給開發者提供了設備創建、獲取接口、接收Event事件、收發數據等驅動能力接口，如圖5所示：

首先，需構造描述符來說明設備的總體信息。開發者可以通過設備功能代碼及設備私有數據HCS兩種途徑進行配置，下面將分別介紹。

static struct UsbFnFunction g_acmFunction = {//功能描述符    .enable         = true,    .funcName       = "f_generic.a",    .strings        = g_acmStrings,    .fsDescriptors  = g_acmFsFunction,    .hsDescriptors  = g_acmHsFunction,    .ssDescriptors  = g_acmSsFunction,.sspDescriptors = NULL,};struct UsbFnFunction *g_functions[] = {#ifdef CDC_ECM    &g_ecmFunction,#endif#ifdef CDC_ACM    &g_acmFunction,#endifNULL};static struct UsbFnConfiguration g_masterConfig = {//配置描述符    .configurationValue = 1,    .iConfiguration     = USB_FUNC_CONFIG_IDX,    .attributes         = USB_CFG_BUS_POWERED,    .maxPower           = POWER,    .functions          = g_functions,};static struct UsbFnConfiguration *g_configs[] = {    &g_masterConfig,    NULL,};static struct UsbDeviceDescriptor g_cdcMasterDeviceDesc = {//設備描述符    .bLength            = sizeof(g_cdcMasterDeviceDesc),    .bDescriptorType    = USB_DDK_DT_DEVICE,    .bcdUSB             = CpuToLe16(BCD_USB),    .bDeviceClass       = 0,    .bDeviceSubClass    = 0,    .bDeviceProtocol    = 0,    .bMaxPacketSize0    = USB_MAX_PACKET_SIZE,    .idVendor           = CpuToLe16(DEVICE_VENDOR_ID),    .idProduct          = CpuToLe16(DEVICE_PRODUCT_ID),    .bcdDevice          = CpuToLe16(DEVICE_VERSION),    .iManufacturer      = USB_FUNC_MANUFACTURER_IDX,    .iProduct           = USB_FUNC_PRODUCT_IDX,    .iSerialNumber      = USB_FUNC_SERIAL_IDX,    .bNumConfigurations = 1,};static struct UsbFnDeviceDesc g_masterFuncDevice = {//描述符入口    .deviceDesc    = &g_cdcMasterDeviceDesc,    .deviceStrings = g_devStrings,    .configs       = g_configs,};

root {    module = "master";master_config {        match_attr         = "usbfn_master_driver";//該字段與device中deviceMatchAttr                                                             保持一致，否則無法找到的這個節點的信息。    use_hcs            = 1;                         //用戶可以用該值決定是否使用hcs配置信息    udc_name           = "100e0000.hidwc3_0";   //UDC的名字        usb_dev_desc       = "UsbDeviceDescriptor";//設備描述符的節點UsbDeviceDescriptor        usb_dev_string     = "UsbDeviceStrings";   //設備字符串的節點為UsbDeviceStrings        usb_configuration = "UsbConfigs";           //配置描述符的節點為UsbConfigs        ...   }}

UsbDeviceDescriptor {            bLength            = 18;            bDescriptorType  = 0x01;            bcdUSB             = 0x0200;            bDeviceClass      = 0;            bDeviceSubClass  = 0;            bDeviceProtocol  = 0;            bMaxPacketSize0  = 0x40;            idVendor           = 0x0525;            idProduct          = 0xA4A7;            bcdDevice          = 0x0100;            manufacturer       = 0;            product             = 1;            serialnumber       = 2;            numConfigurations = 1;  }

描述符構造完成后，使用UsbFnDeviceCreate函數創建一個USB設備，并傳入UDC控制器名和UsbFnDescriptorData結構體。實現代碼如下：

 if (useHcs == 0) {//使用代碼編寫的描述符        descData.type        = USBFN_DESC_DATA_TYPE_DESC;        descData.descriptor = &g_acmFuncDevice;    } else {             //使用hcs編寫的描述符        descData.type         = USBFN_DESC_DATA_TYPE_PROP;        descData.property    = acm->device->property;}   //創建設備    fnDev = (struct UsbFnDevice *) UsbFnCreateDevice(acm->udcName, &descData);

設備創建后，使用UsbFnDeviceGetInterface函數獲取UsbInterface接口對象，并通過UsbFnGetInterfacePipeInfo函數獲取USB管道信息，實現代碼如下：

//獲取接口fnIface = (struct UsbFnInterface *)UsbFnGetInterface(fnDev, i);//獲取Pipe信息UsbFnGetInterfacePipeInfo(fnIface, i, &pipeInfo);//獲取Handlehandle = UsbFnOpenInterface(fnIface);//獲取控制（EP0）Requestreq = UsbFnAllocCtrlRequest(acm->ctrlIface.handle,            sizeof(struct UsbCdcLineCoding) + sizeof(struct UsbCdcLineCoding));//獲取Requestreq = UsbFnAllocCtrlRequest(acm->ctrlIface.handle,            sizeof(struct UsbCdcLineCoding) + sizeof(struct UsbCdcLineCoding));

通過UsbFnStartRecvInterfaceEvent函數接收Event事件，并通過UsbFnEventCallback回調函數對Event事件做出響應，實現代碼如下：

//開始接收Event事件ret = UsbFnStartRecvInterfaceEvent(acm->ctrlIface.fn, 0xff, UsbAcmEventCallback, acm);//Event處理回調函數static void UsbAcmEventCallback(struct UsbFnEvent *event){struct UsbAcmDevice *acm = NULL;

    if (event == NULL || event->context == NULL) {        HDF_LOGE("%s: event is null", __func__);        return;    }

    acm = (struct UsbAcmDevice *)event->context;    switch (event->type) {        case USBFN_STATE_BIND:            HDF_LOGI("%s: receive bind event", __func__);            break;        case USBFN_STATE_UNBIND:            HDF_LOGI("%s: receive unbind event", __func__);            break;        case USBFN_STATE_ENABLE:            HDF_LOGI("%s: receive enable event", __func__);            AcmEnable(acm);            break;        case USBFN_STATE_DISABLE:            HDF_LOGI("%s: receive disable event", __func__);            AcmDisable(acm);            acm->enableEvtCnt = 0;            break;        case USBFN_STATE_SETUP:            HDF_LOGI("%s: receive setup event", __func__);            if (event->setup != NULL) {                AcmSetup(acm, event->setup);            }            break;        case USBFN_STATE_SUSPEND:            HDF_LOGI("%s: receive suspend event", __func__);            AcmSuspend(acm);            break;        case USBFN_STATE_RESUME:            HDF_LOGI("%s: receive resume event", __func__);            AcmResume(acm);            break;        default:            break;    }}

可以選擇同步異步發送模式，實現代碼如下：

notify = (struct UsbCdcNotification *)req->buf;    ...    if (memcpy_s((void *)(notify + 1), length, data, length)  != EOK) {        return HDF_FAILURE;    }ret = UsbFnSubmitRequestAsync(req);//異步發送