usbd_get_no_alts
numalts = usbd_get_no_alts(cd, id->bInterfaceNumber);
altnum = usbd_get_no_alts(cd, data_ifaceno);
altcnt = usbd_get_no_alts(cd, id->bInterfaceNumber);
ai->uai_alt_no = usbd_get_no_alts(cdesc,
int usbd_get_no_alts(usb_config_descriptor_t *, int);
numalts = usbd_get_no_alts(cdesc, id->bInterfaceNumber);