file usb_bsp.c:

void USB_OTG_BSP_Init(USB_OTG_CORE_HANDLE *pdev) {
  GPIO_InitTypeDef GPIO_InitStructure;
#ifdef USE_USB_OTG_FS
    RCC_AHBPeriphClockCmd( RCC_AHBPeriph_GPIOA , ENABLE);  // Bus RCC_AHB1Periph to RCC_AHBPeriph
    GPIO_InitStructure.GPIO_Pin =   GPIO_Pin_11 |   // OTG FS Data -
                                    GPIO_Pin_12;    // OTG FS Data +

    GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz; // GPIO_Speed_100MHz to GPIO_Speed_50MHz
    GPIO_InitStructure.GPIO_Mode = GPIO_Mode_AF;
    GPIO_InitStructure.GPIO_OType = GPIO_OType_PP;
    GPIO_InitStructure.GPIO_PuPd = GPIO_PuPd_NOPULL ;
    GPIO_Init(GPIOA, &GPIO_InitStructure);

    GPIO_PinAFConfig(GPIOA, GPIO_PinSource11, GPIO_AF_14); //GPIO_AF_OTG1_FS to GPIO_AF_14
    GPIO_PinAFConfig(GPIOA, GPIO_PinSource12, GPIO_AF_14); //GPIO_AF_OTG1_FS to GPIO_AF_14
#ifndef USB_VCP_DISABLE_VBUS
    // Configure  VBUS Pin
    GPIO_InitStructure.GPIO_Pin = GPIO_Pin_9;
    GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz; // GPIO_Speed_100MHz to GPIO_Speed_50MHz
    GPIO_InitStructure.GPIO_Mode = GPIO_Mode_IN;
    GPIO_InitStructure.GPIO_OType = GPIO_OType_OD;
    GPIO_InitStructure.GPIO_PuPd = GPIO_PuPd_NOPULL ;
    GPIO_Init(GPIOA, &GPIO_InitStructure);
#endif

#ifndef USB_VCP_DISABLE_ID
    // Configure ID pin
    GPIO_InitStructure.GPIO_Pin = GPIO_Pin_10;
    GPIO_InitStructure.GPIO_OType = GPIO_OType_OD;
    GPIO_InitStructure.GPIO_PuPd = GPIO_PuPd_UP ;
    GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz;  // GPIO_Speed_100MHz to GPIO_Speed_50MHz
    GPIO_Init(GPIOA, &GPIO_InitStructure);
    GPIO_PinAFConfig(GPIOA, GPIO_PinSource10, GPIO_AF_14); //GPIO_AF_OTG1_FS to GPIO_AF_14
#endif

    RCC_APB2PeriphClockCmd(RCC_APB2Periph_SYSCFG, ENABLE);
    RCC_APB1PeriphClockCmd(RCC_APB1Periph_USB, ENABLE); //RCC_AHB2Periph_OTG_FS to RCC_APB1Periph_USB

////......
////////////////////////////////////////////// --- // --- //////////////////////////

void USB_OTG_BSP_EnableInterrupt(USB_OTG_CORE_HANDLE *pdev) {
    NVIC_InitTypeDef NVIC_InitStructure;
#ifdef USE_USB_OTG_FS
    NVIC_PriorityGroupConfig(NVIC_PriorityGroup_1);
    NVIC_InitStructure.NVIC_IRQChannel = USB_HP_IRQn;  //OTG_FS_IRQn to USB_HP_IRQn or USB_LP_IRQn (?)
    NVIC_InitStructure.NVIC_IRQChannelPreemptionPriority = USB_VCP_NVIC_PRIORITY;
    NVIC_InitStructure.NVIC_IRQChannelSubPriority = USB_VCP_NVIC_SUBPRIORITY + 2;
    NVIC_InitStructure.NVIC_IRQChannelCmd = ENABLE;
    NVIC_Init(&NVIC_InitStructure);
#else
    NVIC_PriorityGroupConfig(NVIC_PriorityGroup_1);
    NVIC_InitStructure.NVIC_IRQChannel = OTG_HS_IRQn;
    NVIC_InitStructure.NVIC_IRQChannelPreemptionPriority = USB_VCP_NVIC_PRIORITY;
    NVIC_InitStructure.NVIC_IRQChannelSubPriority = USB_VCP_NVIC_SUBPRIORITY + 2;
    NVIC_InitStructure.NVIC_IRQChannelCmd = ENABLE;
    NVIC_Init(&NVIC_InitStructure);

    NVIC_PriorityGroupConfig(NVIC_PriorityGroup_1);
    NVIC_InitStructure.NVIC_IRQChannel = OTG_HS_EP1_OUT_IRQn;
    NVIC_InitStructure.NVIC_IRQChannelPreemptionPriority = USB_VCP_NVIC_PRIORITY;
    NVIC_InitStructure.NVIC_IRQChannelSubPriority = USB_VCP_NVIC_SUBPRIORITY + 1;
    NVIC_InitStructure.NVIC_IRQChannelCmd = ENABLE;
    NVIC_Init(&NVIC_InitStructure);

    NVIC_PriorityGroupConfig(NVIC_PriorityGroup_1);
    NVIC_InitStructure.NVIC_IRQChannel = OTG_HS_EP1_IN_IRQn;
    NVIC_InitStructure.NVIC_IRQChannelPreemptionPriority = USB_VCP_NVIC_PRIORITY;
    NVIC_InitStructure.NVIC_IRQChannelSubPriority = USB_VCP_NVIC_SUBPRIORITY;
    NVIC_InitStructure.NVIC_IRQChannelCmd = ENABLE;
    NVIC_Init(&NVIC_InitStructure);

#endif
}