简单几步让WinUSB设备变为多端点设备

上一篇文章已经详细讲解了如何在STM32平台上实现一个WinUSB免驱设备：

STM32 WinUSB(WCID)免驱高速通信 20M/s（附详细测试）_bingwueyi的博客-CSDN博客_winusb

那现在就在这个工程的基础上改造一下，实现多端点通信，实用性、可玩性、功能扩展性大大增加了！需要说明的是增加端点只会增加功能（数据通道逻辑区分），不会增加传输速率。

USB的接口（Interface）、端点（Endpoint）等概念自行了解一下吧，本文的目的是为了增加功能和区分数据通道，添加了两个端点（Endpoint），下一篇文章将会讲到增加接口，也就是复合设备。

先来张修改对比图，对下面6个文件进行了修改：

直接上代码，以下是对USB HS的修改， FS的配置同理修改即可：

1 修改usbd_cdc.h

1.1 宏定义增中EP3的定义

#define CDC_IN_EP                                   0x81U  /* EP1 for data IN */#define CDC_OUT_EP                                  0x01U  /* EP1 for data OUT */#define CDC_CMD_EP                                  0x82U  /* EP2 for CDC commands *///ADD#define CDCUSER_IN_EP                                   0x83U  /* EP3 for data IN */#define CDCUSER_OUT_EP                                  0x03U  /* EP3 for data OUT */

1.2 结构体 USBD_CDC_ItfTypeDef 的Receive定义修改一下，增加endpoint参数，主要是为了在接收函数中区分是哪个端点的数据：

typedef struct _USBD_CDC_Itf{int8_t (* Init)(void);int8_t (* DeInit)(void);int8_t (* Control)(uint8_t cmd, uint8_t *pbuf, uint16_t length);int8_t (* Receive)(uint8_t *Buf, uint32_t *Len, uint8_t ep); //CHANGEint8_t (* TransmitCplt)(uint8_t *Buf, uint32_t *Len, uint8_t epnum);} USBD_CDC_ItfTypeDef;

1.3 下面两个函数也增加 endpoint参数：

uint8_t USBD_CDC_ReceivePacket(USBD_HandleTypeDef *pdev, uint8_t ep); //CHANGEuint8_t USBD_CDC_TransmitPacket(USBD_HandleTypeDef *pdev, uint8_t ep); //CHANGE

2 修改 usbd_cdc.c

2.1 将 WINUSB_CONFIG_DESC_SIZE 宏的值改为46，该值表示USBD_CDC_CfgHSDesc数组的长度，本文增加了两个端点，第个端点由7个字节表示，所以 32+7+7=46：

#define WINUSB_CONFIG_DESC_SIZE 46 //32  CHANGE

2.2 在数组USBD_CDC_CfgHSDesc中修改EndPoint数量为4，同时增加端点定义：

/*Data class interface descriptor*/0x09,   /* bLength: Endpoint Descriptor size */USB_DESC_TYPE_INTERFACE,  /* bDescriptorType: */0x00,   /* bInterfaceNumber: Number of Interface, zero based index of this interface */0x00,   /* bAlternateSetting: Alternate setting */0x04,   /* bNumEndpoints: Two endpoints used */ //CHANGE0xff,   /* bInterfaceClass: vendor */0x00,   /* bInterfaceSubClass: */0x00,   /* bInterfaceProtocol: */0x00,   /* iInterface: *///此处省略一些代码...//---------------------------------------ADD--------------------------------------------------/*Endpoint OUT Descriptor */0x07,   /* bLength: Endpoint Descriptor size */USB_DESC_TYPE_ENDPOINT,      /* bDescriptorType: Endpoint */CDCUSER_OUT_EP,                        /* bEndpointAddress */0x02,                              /* bmAttributes: Bulk */LOBYTE(CDC_DATA_HS_MAX_PACKET_SIZE),  /* wMaxPacketSize: */HIBYTE(CDC_DATA_HS_MAX_PACKET_SIZE),0x00,                                       /* bInterval: ignore for Bulk transfer *//* Endpoint IN Descriptor */0x07,                                       /* bLength: Endpoint Descriptor size */USB_DESC_TYPE_ENDPOINT,                     /* bDescriptorType: Endpoint */CDCUSER_IN_EP,                                  /* bEndpointAddress */0x02,                                       /* bmAttributes: Bulk */LOBYTE(CDC_DATA_HS_MAX_PACKET_SIZE),        /* wMaxPacketSize: */HIBYTE(CDC_DATA_HS_MAX_PACKET_SIZE),0x00                                        /* bInterval: ignore for Bulk transfer *///---------------------------------------------------------------------------------------------

2.3 在 USBD_CDC_Init 函数中增加端点初始化(省略了一些代码，找准位置哦)：

 //--------------------ADD--------------------------------/* Open USER EP IN */(void)USBD_LL_OpenEP(pdev, CDCUSER_IN_EP, USBD_EP_TYPE_BULK,CDC_DATA_HS_IN_PACKET_SIZE);pdev->ep_in[CDCUSER_IN_EP & 0xFU].is_used = 1U;/* Open USER EP OUT */(void)USBD_LL_OpenEP(pdev, CDCUSER_OUT_EP, USBD_EP_TYPE_BULK,CDC_DATA_HS_OUT_PACKET_SIZE);pdev->ep_out[CDCUSER_OUT_EP & 0xFU].is_used = 1U;//省略(void)USBD_LL_PrepareReceive(pdev, CDCUSER_OUT_EP, hcdc->RxBuffer,CDC_DATA_HS_OUT_PACKET_SIZE);//-----------------------------------------------------------

2.4 在 USBD_CDC_DeInit 函数中增加：

//----------------------ADD----------------------/* Close EP IN */(void)USBD_LL_CloseEP(pdev, CDCUSER_IN_EP);pdev->ep_in[CDCUSER_IN_EP & 0xFU].is_used = 0U;/* Close EP OUT */(void)USBD_LL_CloseEP(pdev, CDCUSER_OUT_EP);pdev->ep_out[CDCUSER_OUT_EP & 0xFU].is_used = 0U;//--------------------------------------------------

2.5 在 USBD_CDC_DataOut 函数中修改Receive，传入ep参数：

((USBD_CDC_ItfTypeDef *)pdev->pUserData)->Receive(hcdc->RxBuffer, &hcdc->RxLength, epnum);  //CHANGE

同样的，下面两个函数也做相应的修改，传入ep参数：

uint8_t USBD_CDC_TransmitPacket(USBD_HandleTypeDef *pdev, uint8_t ep)  //CHANGE
{USBD_CDC_HandleTypeDef *hcdc = (USBD_CDC_HandleTypeDef *)pdev->pClassData;USBD_StatusTypeDef ret = USBD_BUSY;if (pdev->pClassData == NULL){return (uint8_t)USBD_FAIL;}if (hcdc->TxState == 0U){/* Tx Transfer in progress */hcdc->TxState = 1U;/* Update the packet total length */pdev->ep_in[ep & 0xFU].total_length = hcdc->TxLength;  //CHANGE/* Transmit next packet */(void)USBD_LL_Transmit(pdev, ep, hcdc->TxBuffer, hcdc->TxLength);  //CHANGEret = USBD_OK;}return (uint8_t)ret;
}uint8_t USBD_CDC_ReceivePacket(USBD_HandleTypeDef *pdev, uint8_t ep)  //CHANGE
{USBD_CDC_HandleTypeDef *hcdc = (USBD_CDC_HandleTypeDef *)pdev->pClassData;if (pdev->pClassData == NULL){return (uint8_t)USBD_FAIL;}if (pdev->dev_speed == USBD_SPEED_HIGH){/* Prepare Out endpoint to receive next packet */(void)USBD_LL_PrepareReceive(pdev, ep, hcdc->RxBuffer,  //CHANGECDC_DATA_HS_OUT_PACKET_SIZE);}else{/* Prepare Out endpoint to receive next packet */(void)USBD_LL_PrepareReceive(pdev, ep, hcdc->RxBuffer,  //CHANGECDC_DATA_FS_OUT_PACKET_SIZE);}return (uint8_t)USBD_OK;
}

3 修改 usbd_cdc_if.c

3.1 修改 CDC_Receive_HS 函数定义：

static int8_t CDC_Receive_HS(uint8_t* pbuf, uint32_t *Len, uint8_t ep); //CHANGE

3.2 增加接收缓冲区和修改收发函数：

//-----------------ADD GUOXUAN-----------------------extern volatile int8_t usb_ep1_rxne;extern uint8_t usb_ep1_rx[2048];extern volatile int8_t usb_ep3_rxne;extern uint8_t usb_ep3_rx[2048];//---------------------------------------------------static int8_t CDC_Receive_HS(uint8_t* Buf, uint32_t *Len, uint8_t ep) //CHANGE{/* USER CODE BEGIN 11 *///-------------ADD GUOXUAN--------------------switch(ep){case CDC_OUT_EP:memcpy(usb_ep1_rx, Buf, *Len);usb_ep1_rxne = SET;break;case CDCUSER_OUT_EP:memcpy(usb_ep3_rx, Buf, *Len);usb_ep3_rxne = SET;break;default:break;}//--------------------------------------------USBD_CDC_SetRxBuffer(&hUsbDeviceHS, &Buf[0]);USBD_CDC_ReceivePacket(&hUsbDeviceHS, ep);  //CHANGEreturn (USBD_OK);/* USER CODE END 11 */}uint8_t CDC_Transmit_HS(uint8_t* Buf, uint16_t Len, uint8_t ep)  //CHANGE{uint8_t result = USBD_OK;/* USER CODE BEGIN 12 */USBD_CDC_HandleTypeDef *hcdc = (USBD_CDC_HandleTypeDef*)hUsbDeviceHS.pClassData;if (hcdc->TxState != 0){return USBD_BUSY;}USBD_CDC_SetTxBuffer(&hUsbDeviceHS, Buf, Len); //todo:result = USBD_CDC_TransmitPacket(&hUsbDeviceHS, ep);  //CHANGE/* USER CODE END 12 */return result;}

4 修改 usbd_cdc_if.h

4.1 函数 CDC_Transmit_HS 增加ep参数：

uint8_t CDC_Transmit_HS(uint8_t* Buf, uint16_t Len, uint8_t ep); //CHANGE

5 修改 usbd_conf.c

5.1 在 USBD_LL_Init 函数尾部增加txFifo初始化：

HAL_PCDEx_SetRxFiFo(&hpcd_USB_OTG_HS, 0x200);HAL_PCDEx_SetTxFiFo(&hpcd_USB_OTG_HS, 0, 0x80);HAL_PCDEx_SetTxFiFo(&hpcd_USB_OTG_HS, 1, 0x174);HAL_PCDEx_SetTxFiFo(&hpcd_USB_OTG_HS, 3, 0x174); //ADD

6 最后在main.c里增加收发控制：

//--------------ADD GUOXUAN-----------------------uint8_t usb_ep1_rx[2048];uint8_t usb_ep1_tx[40960];uint8_t usb_ep3_rx[2048];uint8_t usb_ep3_tx[40960];volatile int8_t usb_ep1_rxne = RESET;volatile int8_t usb_ep3_rxne = RESET;extern USBD_HandleTypeDef hUsbDeviceHS;//-----------------------------------------------//------------ADD GUOXUAN-------------------void WinUSB_Receive_HS(){uint16_t i = 0;if (usb_ep1_rxne == SET){i = usb_ep1_rx[0] + (usb_ep1_rx[1]<<8);CDC_Transmit_HS(usb_ep1_tx, i, CDC_IN_EP);usb_ep1_rxne = RESET;}else if(usb_ep3_rxne == SET){i = usb_ep3_rx[0] + (usb_ep3_rx[1]<<8);CDC_Transmit_HS(usb_ep3_tx, i, CDCUSER_IN_EP);usb_ep3_rxne = RESET;}}//------------------------------------------

至此，修改已全部完成，下面进行测试。

在WIN10平台，使用VS2015创建C++工程，测试方法同上一篇文章，上位机发送一个64字节的包，前两字节表示要回复的长度，下位机收到后回复一个相应长度的包，重复收发1000次统计速率，按下数字选择包大小，回车即对两个端点进行测试，结果如下图所示（未使用多线程）：

上位机原码下载：

https://download.csdn.net/download/bingwueyi/86399991