wifi: mt76: mt7921: add ack signal support

This reports signal strength of ACK packets from the peer as measured
at each interface.

Reviewed-by: Ryder Lee <[email protected]>
Signed-off-by: Deren Wu <[email protected]>
Reviewed-by: AngeloGioacchino Del Regno <[email protected]>
Signed-off-by: Felix Fietkau <[email protected]>

Author: deren

drivers/net/wireless/mediatek/mt76/mt7921/init.c

@@ -120,6 +120,7 @@ mt7921_init_wiphy(struct ieee80211_hw *hw)
 	wiphy_ext_feature_set(wiphy, NL80211_EXT_FEATURE_BEACON_RATE_HT);
 	wiphy_ext_feature_set(wiphy, NL80211_EXT_FEATURE_BEACON_RATE_VHT);
 	wiphy_ext_feature_set(wiphy, NL80211_EXT_FEATURE_BEACON_RATE_HE);
+	wiphy_ext_feature_set(wiphy, NL80211_EXT_FEATURE_ACK_SIGNAL_SUPPORT);
 
 	ieee80211_hw_set(hw, SINGLE_SCAN_ON_ALL_BANDS);
 	ieee80211_hw_set(hw, HAS_RATE_CONTROL);
@@ -142,6 +143,8 @@ mt7921_init_wiphy(struct ieee80211_hw *hw)
 static void
 mt7921_mac_init_band(struct mt7921_dev *dev, u8 band)
 {
+	u32 mask, set;
+
 	mt76_rmw_field(dev, MT_TMAC_CTCR0(band),
 		       MT_TMAC_CTCR0_INS_DDLMT_REFTIME, 0x3f);
 	mt76_set(dev, MT_TMAC_CTCR0(band),
@@ -158,6 +161,12 @@ mt7921_mac_init_band(struct mt7921_dev *dev, u8 band)
 	mt76_rmw_field(dev, MT_DMA_DCR0(band), MT_DMA_DCR0_MAX_RX_LEN, 1536);
 	/* disable rx rate report by default due to hw issues */
 	mt76_clear(dev, MT_DMA_DCR0(band), MT_DMA_DCR0_RXD_G5_EN);
+
+	/* filter out non-resp frames and get instantaneous signal reporting */
+	mask = MT_WTBLOFF_TOP_RSCR_RCPI_MODE | MT_WTBLOFF_TOP_RSCR_RCPI_PARAM;
+	set = FIELD_PREP(MT_WTBLOFF_TOP_RSCR_RCPI_MODE, 0) |
+	      FIELD_PREP(MT_WTBLOFF_TOP_RSCR_RCPI_PARAM, 0x3);
+	mt76_rmw(dev, MT_WTBLOFF_TOP_RSCR(band), mask, set);
 }
 
 u8 mt7921_check_offload_capability(struct device *dev, const char *fw_wm)

drivers/net/wireless/mediatek/mt76/mt7921/mac.c

@@ -59,6 +59,7 @@ void mt7921_mac_sta_poll(struct mt7921_dev *dev)
 	u32 tx_time[IEEE80211_NUM_ACS], rx_time[IEEE80211_NUM_ACS];
 	LIST_HEAD(sta_poll_list);
 	struct rate_info *rate;
+	s8 rssi[4];
 	int i;
 
 	spin_lock_bh(&dev->sta_poll_lock);
@@ -160,6 +161,20 @@ void mt7921_mac_sta_poll(struct mt7921_dev *dev)
 			else
 				rate->flags &= ~RATE_INFO_FLAGS_SHORT_GI;
 		}
+
+		/* get signal strength of resp frames (CTS/BA/ACK) */
+		addr = mt7921_mac_wtbl_lmac_addr(idx, 30);
+		val = mt76_rr(dev, addr);
+
+		rssi[0] = to_rssi(GENMASK(7, 0), val);
+		rssi[1] = to_rssi(GENMASK(15, 8), val);
+		rssi[2] = to_rssi(GENMASK(23, 16), val);
+		rssi[3] = to_rssi(GENMASK(31, 14), val);
+
+		msta->ack_signal =
+			mt76_rx_signal(msta->vif->phy->mt76->antenna_mask, rssi);
+
+		ewma_avg_signal_add(&msta->avg_ack_signal, -msta->ack_signal);
 	}
 }
 EXPORT_SYMBOL_GPL(mt7921_mac_sta_poll);

drivers/net/wireless/mediatek/mt76/mt7921/main.c

@@ -855,6 +855,8 @@ void mt7921_mac_sta_assoc(struct mt76_dev *mdev, struct ieee80211_vif *vif,
 		mt76_connac_mcu_uni_add_bss(&dev->mphy, vif, &mvif->sta.wcid,
 					    true, mvif->ctx);
 
+	ewma_avg_signal_init(&msta->avg_ack_signal);
+
 	mt7921_mac_wtbl_update(dev, msta->wcid.idx,
 			       MT_WTBL_UPDATE_ADM_COUNT_CLEAR);
 	memset(msta->airtime_ac, 0, sizeof(msta->airtime_ac));
@@ -1425,6 +1427,12 @@ static void mt7921_sta_statistics(struct ieee80211_hw *hw,
 	}
 	sinfo->txrate.flags = txrate->flags;
 	sinfo->filled |= BIT_ULL(NL80211_STA_INFO_TX_BITRATE);
+
+	sinfo->ack_signal = (s8)msta->ack_signal;
+	sinfo->filled |= BIT_ULL(NL80211_STA_INFO_ACK_SIGNAL);
+
+	sinfo->avg_ack_signal = -(s8)ewma_avg_signal_read(&msta->avg_ack_signal);
+	sinfo->filled |= BIT_ULL(NL80211_STA_INFO_ACK_SIGNAL_AVG);
 }
 
 #ifdef CONFIG_PM

drivers/net/wireless/mediatek/mt76/mt7921/mt7921.h

@@ -144,6 +144,8 @@ enum mt7921_rxq_id {
 	MT7921_RXQ_MCU_WM = 0,
 };
 
+DECLARE_EWMA(avg_signal, 10, 8)
+
 struct mt7921_sta {
 	struct mt76_wcid wcid; /* must be first */
 
@@ -152,6 +154,9 @@ struct mt7921_sta {
 	struct list_head poll_list;
 	u32 airtime_ac[8];
 
+	int ack_signal;
+	struct ewma_avg_signal avg_ack_signal;
+
 	unsigned long last_txs;
 	unsigned long ampdu_state;
 

drivers/net/wireless/mediatek/mt76/mt7921/regs.h

@@ -80,6 +80,14 @@
 #define MT_DMA_DCR0_MAX_RX_LEN		GENMASK(15, 3)
 #define MT_DMA_DCR0_RXD_G5_EN		BIT(23)
 
+/* WTBLOFF TOP: band 0(0x820e9000),band 1(0x820f9000) */
+#define MT_WTBLOFF_TOP_BASE(_band)	((_band) ? 0x820f9000 : 0x820e9000)
+#define MT_WTBLOFF_TOP(_band, ofs)	(MT_WTBLOFF_TOP_BASE(_band) + (ofs))
+
+#define MT_WTBLOFF_TOP_RSCR(_band)	MT_WTBLOFF_TOP(_band, 0x008)
+#define MT_WTBLOFF_TOP_RSCR_RCPI_MODE	GENMASK(31, 30)
+#define MT_WTBLOFF_TOP_RSCR_RCPI_PARAM	GENMASK(25, 24)
+
 /* LPON: band 0(0x24200), band 1(0xa4200) */
 #define MT_WF_LPON_BASE(_band)		((_band) ? 0x820fb000 : 0x820eb000)
 #define MT_WF_LPON(_band, ofs)		(MT_WF_LPON_BASE(_band) + (ofs))