ath9k: implement .get_antenna and .set_antenna

On MIMO chips this can be used to enable/disable hardware chains, ensuring
that the MCS information is updated accordingly.
On non-MIMO chips with rx diversity (e.g. 9285), this configures the rx
input antenna.
Signed-off-by: Felix Fietkau <nbd@openwrt.org>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

drivers/net/wireless/ath/ath9k/ath9k.h

@@ -649,6 +649,7 @@ struct ath_softc {
 	struct ath_descdma txsdma;
 
 	struct ath_ant_comb ant_comb;
+	u8 ant_tx, ant_rx;
 };
 
 void ath9k_tasklet(unsigned long data);
@@ -669,6 +670,7 @@ int ath9k_init_device(u16 devid, struct ath_softc *sc,
 		    const struct ath_bus_ops *bus_ops);
 void ath9k_deinit_device(struct ath_softc *sc);
 void ath9k_set_hw_capab(struct ath_softc *sc, struct ieee80211_hw *hw);
+void ath9k_reload_chainmask_settings(struct ath_softc *sc);
 
 void ath_radio_disable(struct ath_softc *sc, struct ieee80211_hw *hw);
 bool ath9k_uses_beacons(int type);

drivers/net/wireless/ath/ath9k/init.c

@@ -653,9 +653,22 @@ static void ath9k_init_txpower_limits(struct ath_softc *sc)
 	ah->curchan = curchan;
 }
 
+void ath9k_reload_chainmask_settings(struct ath_softc *sc)
+{
+	if (!(sc->sc_ah->caps.hw_caps & ATH9K_HW_CAP_HT))
+		return;
+
+	if (sc->sc_ah->caps.hw_caps & ATH9K_HW_CAP_2GHZ)
+		setup_ht_cap(sc, &sc->sbands[IEEE80211_BAND_2GHZ].ht_cap);
+	if (sc->sc_ah->caps.hw_caps & ATH9K_HW_CAP_5GHZ)
+		setup_ht_cap(sc, &sc->sbands[IEEE80211_BAND_5GHZ].ht_cap);
+}
+
+
 void ath9k_set_hw_capab(struct ath_softc *sc, struct ieee80211_hw *hw)
 {
-	struct ath_common *common = ath9k_hw_common(sc->sc_ah);
+	struct ath_hw *ah = sc->sc_ah;
+	struct ath_common *common = ath9k_hw_common(ah);
 
 	hw->flags = IEEE80211_HW_RX_INCLUDES_FCS |
 		IEEE80211_HW_HOST_BROADCAST_PS_BUFFERING |
@@ -693,6 +706,16 @@ void ath9k_set_hw_capab(struct ath_softc *sc, struct ieee80211_hw *hw)
 	hw->sta_data_size = sizeof(struct ath_node);
 	hw->vif_data_size = sizeof(struct ath_vif);
 
+	hw->wiphy->available_antennas_rx = BIT(ah->caps.max_rxchains) - 1;
+	hw->wiphy->available_antennas_tx = BIT(ah->caps.max_txchains) - 1;
+
+	/* single chain devices with rx diversity */
+	if (ah->caps.hw_caps & ATH9K_HW_CAP_ANT_DIV_COMB)
+		hw->wiphy->available_antennas_rx = BIT(0) | BIT(1);
+
+	sc->ant_rx = hw->wiphy->available_antennas_rx;
+	sc->ant_tx = hw->wiphy->available_antennas_tx;
+
 #ifdef CONFIG_ATH9K_RATE_CONTROL
 	hw->rate_control_algorithm = "ath9k_rate_control";
 #endif
@@ -704,12 +727,7 @@ void ath9k_set_hw_capab(struct ath_softc *sc, struct ieee80211_hw *hw)
 		hw->wiphy->bands[IEEE80211_BAND_5GHZ] =
 			&sc->sbands[IEEE80211_BAND_5GHZ];
 
-	if (sc->sc_ah->caps.hw_caps & ATH9K_HW_CAP_HT) {
-		if (sc->sc_ah->caps.hw_caps & ATH9K_HW_CAP_2GHZ)
-			setup_ht_cap(sc, &sc->sbands[IEEE80211_BAND_2GHZ].ht_cap);
-		if (sc->sc_ah->caps.hw_caps & ATH9K_HW_CAP_5GHZ)
-			setup_ht_cap(sc, &sc->sbands[IEEE80211_BAND_5GHZ].ht_cap);
-	}
+	ath9k_reload_chainmask_settings(sc);
 
 	SET_IEEE80211_PERM_ADDR(hw, common->macaddr);
 }

drivers/net/wireless/ath/ath9k/main.c

@@ -281,6 +281,22 @@ static bool ath_complete_reset(struct ath_softc *sc, bool start)
 			ath_start_ani(common);
 	}
 
+	if (ath9k_hw_ops(ah)->antdiv_comb_conf_get && sc->ant_rx != 3) {
+		struct ath_hw_antcomb_conf div_ant_conf;
+		u8 lna_conf;
+
+		ath9k_hw_antdiv_comb_conf_get(ah, &div_ant_conf);
+
+		if (sc->ant_rx == 1)
+			lna_conf = ATH_ANT_DIV_COMB_LNA1;
+		else
+			lna_conf = ATH_ANT_DIV_COMB_LNA2;
+		div_ant_conf.main_lna_conf = lna_conf;
+		div_ant_conf.alt_lna_conf = lna_conf;
+
+		ath9k_hw_antdiv_comb_conf_set(ah, &div_ant_conf);
+	}
+
 	ieee80211_wake_queues(sc->hw);
 
 	return true;
@@ -2379,6 +2395,59 @@ static int ath9k_get_stats(struct ieee80211_hw *hw,
 	return 0;
 }
 
+static u32 fill_chainmask(u32 cap, u32 new)
+{
+	u32 filled = 0;
+	int i;
+
+	for (i = 0; cap && new; i++, cap >>= 1) {
+		if (!(cap & BIT(0)))
+			continue;
+
+		if (new & BIT(0))
+			filled |= BIT(i);
+
+		new >>= 1;
+	}
+
+	return filled;
+}
+
+static int ath9k_set_antenna(struct ieee80211_hw *hw, u32 tx_ant, u32 rx_ant)
+{
+	struct ath_softc *sc = hw->priv;
+	struct ath_hw *ah = sc->sc_ah;
+
+	if (!rx_ant || !tx_ant)
+		return -EINVAL;
+
+	sc->ant_rx = rx_ant;
+	sc->ant_tx = tx_ant;
+
+	if (ah->caps.rx_chainmask == 1)
+		return 0;
+
+	/* AR9100 runs into calibration issues if not all rx chains are enabled */
+	if (AR_SREV_9100(ah))
+		ah->rxchainmask = 0x7;
+	else
+		ah->rxchainmask = fill_chainmask(ah->caps.rx_chainmask, rx_ant);
+
+	ah->txchainmask = fill_chainmask(ah->caps.tx_chainmask, tx_ant);
+	ath9k_reload_chainmask_settings(sc);
+
+	return 0;
+}
+
+static int ath9k_get_antenna(struct ieee80211_hw *hw, u32 *tx_ant, u32 *rx_ant)
+{
+	struct ath_softc *sc = hw->priv;
+
+	*tx_ant = sc->ant_tx;
+	*rx_ant = sc->ant_rx;
+	return 0;
+}
+
 struct ieee80211_ops ath9k_ops = {
 	.tx 		    = ath9k_tx,
 	.start 		    = ath9k_start,
@@ -2405,4 +2474,6 @@ struct ieee80211_ops ath9k_ops = {
 	.tx_frames_pending  = ath9k_tx_frames_pending,
 	.tx_last_beacon     = ath9k_tx_last_beacon,
 	.get_stats	    = ath9k_get_stats,
+	.set_antenna	    = ath9k_set_antenna,
+	.get_antenna	    = ath9k_get_antenna,
 };

drivers/net/wireless/ath/ath9k/recv.c

@@ -1950,7 +1950,7 @@ int ath_rx_tasklet(struct ath_softc *sc, int flush, bool hp)
 			ath_rx_ps(sc, skb);
 		spin_unlock_irqrestore(&sc->sc_pm_lock, flags);
 
-		if (ah->caps.hw_caps & ATH9K_HW_CAP_ANT_DIV_COMB)
+		if ((ah->caps.hw_caps & ATH9K_HW_CAP_ANT_DIV_COMB) && sc->ant_rx == 3)
 			ath_ant_comb_scan(sc, &rs);
 
 		ieee80211_rx(hw, skb);