iwlwifi: mvm: expose device timestamp in radiotap

Set the relevant fields to export the 32-bit device timestamp to
radiotap using the new mac80211 infrastructure. This will be useful
to allow synchronising monitor captures taken on different hardware
simultaneously.
Signed-off-by: NJohannes Berg <johannes.berg@intel.com>
Signed-off-by: NLuca Coelho <luciano.coelho@intel.com>

drivers/net/wireless/intel/iwlwifi/mvm/mac80211.c

@@ -463,6 +463,13 @@ int iwl_mvm_mac_setup_register(struct iwl_mvm *mvm)
 				    IEEE80211_RADIOTAP_MCS_HAVE_STBC;
 	hw->radiotap_vht_details |= IEEE80211_RADIOTAP_VHT_KNOWN_STBC |
 		IEEE80211_RADIOTAP_VHT_KNOWN_BEAMFORMED;
+
+	hw->radiotap_timestamp.units_pos =
+		IEEE80211_RADIOTAP_TIMESTAMP_UNIT_US |
+		IEEE80211_RADIOTAP_TIMESTAMP_SPOS_PLCP_SIG_ACQ;
+	/* this is the case for CCK frames, it's better (only 8) for OFDM */
+	hw->radiotap_timestamp.accuracy = 22;
+
 	hw->rate_control_algorithm = "iwl-mvm-rs";
 	hw->uapsd_queues = IWL_MVM_UAPSD_QUEUES;
 	hw->uapsd_max_sp_len = IWL_UAPSD_MAX_SP;