wifi: rtw89: parse phycap of TX/RX antenna number

Two fields, TX/RX ANT NUM, are introduced to address variant TX/RX antenna
number of hardware. For example, a 1x1 chip with TX diversity, TX NSS = 1
and TX/RX ANT NUM = 2.
Signed-off-by: Ping-Ke Shih <pkshih@realtek.com>
Signed-off-by: Kalle Valo <kvalo@kernel.org>
Link: https://lore.kernel.org/r/20220908074140.39776-3-pkshih@realtek.com

drivers/net/wireless/realtek/rtw89/core.h

@@ -2823,6 +2823,7 @@ struct rtw89_hal {
 	u32 antenna_rx;
 	u8 tx_nss;
 	u8 rx_nss;
+	bool tx_path_diversity;
 	bool support_cckpd;
 	bool support_igi;
 

drivers/net/wireless/realtek/rtw89/mac.c

@@ -2264,6 +2264,8 @@ int rtw89_mac_setup_phycap(struct rtw89_dev *rtwdev)
 	struct rtw89_mac_c2h_info c2h_info = {0};
 	u8 tx_nss;
 	u8 rx_nss;
+	u8 tx_ant;
+	u8 rx_ant;
 	u32 ret;
 
 	ret = rtw89_mac_read_phycap(rtwdev, &c2h_info);
@@ -2272,14 +2274,30 @@ int rtw89_mac_setup_phycap(struct rtw89_dev *rtwdev)
 
 	tx_nss = RTW89_GET_C2H_PHYCAP_TX_NSS(c2h_info.c2hreg);
 	rx_nss = RTW89_GET_C2H_PHYCAP_RX_NSS(c2h_info.c2hreg);
+	tx_ant = RTW89_GET_C2H_PHYCAP_ANT_TX_NUM(c2h_info.c2hreg);
+	rx_ant = RTW89_GET_C2H_PHYCAP_ANT_RX_NUM(c2h_info.c2hreg);
 
 	hal->tx_nss = tx_nss ? min_t(u8, tx_nss, chip->tx_nss) : chip->tx_nss;
 	hal->rx_nss = rx_nss ? min_t(u8, rx_nss, chip->rx_nss) : chip->rx_nss;
 
+	if (tx_ant == 1)
+		hal->antenna_tx = RF_B;
+	if (rx_ant == 1)
+		hal->antenna_rx = RF_B;
+
+	if (tx_nss == 1 && tx_ant == 2 && rx_ant == 2) {
+		hal->antenna_tx = RF_B;
+		hal->tx_path_diversity = true;
+	}
+
 	rtw89_debug(rtwdev, RTW89_DBG_FW,
 		    "phycap hal/phy/chip: tx_nss=0x%x/0x%x/0x%x rx_nss=0x%x/0x%x/0x%x\n",
 		    hal->tx_nss, tx_nss, chip->tx_nss,
 		    hal->rx_nss, rx_nss, chip->rx_nss);
+	rtw89_debug(rtwdev, RTW89_DBG_FW,
+		    "ant num/bitmap: tx=%d/0x%x rx=%d/0x%x\n",
+		    tx_ant, hal->antenna_tx, rx_ant, hal->antenna_rx);
+	rtw89_debug(rtwdev, RTW89_DBG_FW, "TX path diversity=%d\n", hal->tx_path_diversity);
 
 	return 0;
 }

drivers/net/wireless/realtek/rtw89/mac80211.c

@@ -674,12 +674,13 @@ int rtw89_ops_set_antenna(struct ieee80211_hw *hw, u32 tx_ant, u32 rx_ant)
 	struct rtw89_dev *rtwdev = hw->priv;
 	struct rtw89_hal *hal = &rtwdev->hal;
 
-	if (rx_ant != hw->wiphy->available_antennas_rx)
+	if (rx_ant != hw->wiphy->available_antennas_rx && rx_ant != hal->antenna_rx)
 		return -EINVAL;
 
 	mutex_lock(&rtwdev->mutex);
 	hal->antenna_tx = tx_ant;
 	hal->antenna_rx = rx_ant;
+	hal->tx_path_diversity = false;
 	mutex_unlock(&rtwdev->mutex);
 
 	return 0;