Here is a list of all documented struct and union fields with links to the struct/union documentation for each field:

wait_for_monitor : wpa_params
wep_key : wpa_driver_associate_params , wpa_ssid
wep_key_len : wpa_driver_associate_params , wpa_ssid
wep_tx_keyidx : wpa_driver_associate_params , wpa_ssid
wfd_subelems : p2p_peer_info
wmm_params : wpa_event_data::assoc_info
wnm_oper : wpa_driver_ops
workaround : eapol_config
wowlan_triggers : wpa_config
wpa_debug_file_path : wpa_params
wpa_debug_level : wpa_params
wpa_debug_show_keys : wpa_params
wpa_debug_syslog : wpa_params
wpa_debug_timestamp : wpa_params
wpa_debug_tracing : wpa_params
wpa_ie : wpa_driver_associate_params
wpa_ie_len : wpa_driver_associate_params
wpa_proto : wpa_driver_associate_params
wpa_ptk_rekey : wpa_ssid
wpa_version : wpa_driver_ap_params
wpas_mode : wpa_ssid
wps : eap_config , eapol_config , eapol_ctx , radius_server_conf , radius_server_data , wpa_driver_associate_params , wps_config , wps_data
wps_cred_processing : wpa_config
wps_method : p2p_go_neg_results
wps_nfc_dev_pw : wpa_config
wps_nfc_dev_pw_id : wpa_config
wps_nfc_dh_privkey : wpa_config
wps_nfc_dh_pubkey : wpa_config
wps_nfc_pw_from_config : wpa_config
wps_priority : wpa_config
wps_prov_info : p2p_device
wps_sec_dev_type_list : p2p_peer_info
wps_sec_dev_type_list_len : p2p_peer_info
wps_state : wps_context
wps_vendor_ext : p2p_data , wpa_config