usbd_desc_register
usbd_add_interface
usbd_add_endpoint
    struct usbd_tx_rx_msg tx_msg[CONFIG_USBDEV_EP_NUM];
    struct usbd_tx_rx_msg rx_msg[CONFIG_USBDEV_EP_NUM];
struct usbd_interface *intf[16];
usbd_initialize
USBD_IRQHandler
usbd_event_reset_handler
usbd_event_ep0_setup_complete_handler
usbd_event_ep_in_complete_handler
usbd_event_ep_out_complete_handler
usbd_setup_request_handler
tx_msg[ep & 0x7f].cb
rx_msg[ep & 0x7f].cb
usbd_event_ep0_in_complete_handler
tx_msg[ep & 0x7f].cb
usbd_event_ep0_out_complete_handler
rx_msg[ep & 0x7f].cb
usbd_standard_request_handler
usbd_class_request_handler
usbd_vendor_request_handler