wifi: mt76: support power delta calculation for 5 TX paths

One variant of MT7992 has 5 TX paths, so extend the power delta function
to support it. Also, rename nss_delta to path_delta since the value is
based on the number of TX paths rather tha the number of spatial streams.
(path delta [0.5 dBm] = 10 * log(path number) [dBm] * 2)

Co-developed-by: StanleyYP Wang <[e-mail]>
Signed-off-by: StanleyYP Wang <[e-mail]>
Signed-off-by: Shayne Chen <[e-mail]>
Link: https://patch.msgid.link/[e-mail]
Signed-off-by: Felix Fietkau <[e-mail]>

drivers/net/wireless/mediatek/mt76/mac80211.c

···
 	int n_chains = hweight16(phy->chainmask);
 
 	txpower = mt76_get_sar_power(phy, phy->chandef.chan, txpower * 2);
-	txpower -= mt76_tx_power_nss_delta(n_chains);
+	txpower -= mt76_tx_power_path_delta(n_chains);
 
 	return txpower;
 }
···
 		return -EINVAL;
 
 	n_chains = hweight16(phy->chainmask);
-	delta = mt76_tx_power_nss_delta(n_chains);
+	delta = mt76_tx_power_path_delta(n_chains);
 	*dbm = DIV_ROUND_UP(phy->txpower_cur + delta, 2);
 
 	return 0;

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

···
 	return pktid >= MT_PACKET_ID_FIRST;
 }
 
-static inline u8 mt76_tx_power_nss_delta(u8 nss)
+static inline u8 mt76_tx_power_path_delta(u8 path)
 {
-	static const u8 nss_delta[4] = { 0, 6, 9, 12 };
-	u8 idx = nss - 1;
+	static const u8 path_delta[5] = { 0, 6, 9, 12, 14 };
+	u8 idx = path - 1;
 
-	return (idx < ARRAY_SIZE(nss_delta)) ? nss_delta[idx] : 0;
+	return (idx < ARRAY_SIZE(path_delta)) ? path_delta[idx] : 0;
 }
 
 static inline bool mt76_testmode_enabled(struct mt76_phy *phy)

drivers/net/wireless/mediatek/mt76/mt7615/init.c

···
 			 struct ieee80211_supported_band *sband)
 {
 	int i, n_chains = hweight8(dev->mphy.antenna_mask), target_chains;
-	int delta_idx, delta = mt76_tx_power_nss_delta(n_chains);
+	int delta_idx, delta = mt76_tx_power_path_delta(n_chains);
 	u8 *eep = (u8 *)dev->mt76.eeprom.data;
 	enum nl80211_band band = sband->band;
 	struct mt76_power_limits limits;

drivers/net/wireless/mediatek/mt76/mt7615/mcu.c

···
 	};
 
 	tx_power = mt76_get_sar_power(mphy, mphy->chandef.chan, tx_power);
-	tx_power -= mt76_tx_power_nss_delta(n_chains);
+	tx_power -= mt76_tx_power_path_delta(n_chains);
 	tx_power = mt76_get_rate_power_limits(mphy, mphy->chandef.chan,
 					      &limits, tx_power);
 	mphy->txpower_cur = tx_power;
···
 		int delta = 0;
 
 		if (i < n_chains - 1)
-			delta = mt76_tx_power_nss_delta(n_chains) -
-				mt76_tx_power_nss_delta(i + 1);
+			delta = mt76_tx_power_path_delta(n_chains) -
+				mt76_tx_power_path_delta(i + 1);
 		sku[MT_SKU_1SS_DELTA + i] = delta;
 	}
 }

drivers/net/wireless/mediatek/mt76/mt7915/init.c

···
 {
 	struct mt7915_dev *dev = phy->dev;
 	int i, n_chains = hweight16(phy->mt76->chainmask);
-	int nss_delta = mt76_tx_power_nss_delta(n_chains);
+	int path_delta = mt76_tx_power_path_delta(n_chains);
 	int pwr_delta = mt7915_eeprom_get_power_delta(dev, sband->band);
 	struct mt76_power_limits limits;
 
···
 		target_power = mt76_get_rate_power_limits(phy->mt76, chan,
 							  &limits,
 							  target_power);
-		target_power += nss_delta;
+		target_power += path_delta;
 		target_power = DIV_ROUND_UP(target_power, 2);
 		chan->max_power = min_t(int, chan->max_reg_power,
 					target_power);

drivers/net/wireless/mediatek/mt76/mt7996/init.c

···
 				  struct ieee80211_supported_band *sband)
 {
 	struct mt7996_dev *dev = phy->dev;
-	int i, nss = hweight16(phy->mt76->chainmask);
-	int nss_delta = mt76_tx_power_nss_delta(nss);
+	int i, n_chains = hweight16(phy->mt76->chainmask);
+	int path_delta = mt76_tx_power_path_delta(n_chains);
 	int pwr_delta = mt7996_eeprom_get_power_delta(dev, sband->band);
 	struct mt76_power_limits limits;
 
···
 		target_power = mt76_get_rate_power_limits(phy->mt76, chan,
 							  &limits,
 							  target_power);
-		target_power += nss_delta;
+		target_power += path_delta;
 		target_power = DIV_ROUND_UP(target_power, 2);
 		chan->max_power = min_t(int, chan->max_reg_power,
 					target_power);

drivers/net/wireless/mediatek/mt76/mt7996/main.c

···
 	}
 
 	n_chains = hweight16(phy->mt76->chainmask);
-	delta = mt76_tx_power_nss_delta(n_chains);
+	delta = mt76_tx_power_path_delta(n_chains);
 	*dbm = DIV_ROUND_UP(phy->mt76->txpower_cur + delta, 2);
 
 	return 0;