wifi: rtw89: set capability of TX antenna diversity

TX antenna diversity is a mechanism to select a proper antenna from two
antenna for single one hardware PHY chip. It chooses antenna with better
EVM or RSSI, and use GPIO to control SPDT to switch selected antenna.

RFE type from efuse is used to define if a module can support TX antenna
diversity when (type % 3) is 2.
Signed-off-by: Ping-Ke Shih <pkshih@realtek.com>
Signed-off-by: Kalle Valo <kvalo@kernel.org>
Link: https://lore.kernel.org/r/20230418012820.5139-3-pkshih@realtek.com

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

@@ -3701,6 +3701,7 @@ static int rtw89_core_register_hw(struct rtw89_dev *rtwdev)
 {
 	struct ieee80211_hw *hw = rtwdev->hw;
 	struct rtw89_efuse *efuse = &rtwdev->efuse;
+	struct rtw89_hal *hal = &rtwdev->hal;
 	int ret;
 	int tx_headroom = IEEE80211_HT_CTL_LEN;
 
@@ -3739,8 +3740,13 @@ static int rtw89_core_register_hw(struct rtw89_dev *rtwdev)
 				     BIT(NL80211_IFTYPE_P2P_CLIENT) |
 				     BIT(NL80211_IFTYPE_P2P_GO);
 
-	hw->wiphy->available_antennas_tx = BIT(rtwdev->chip->rf_path_num) - 1;
-	hw->wiphy->available_antennas_rx = BIT(rtwdev->chip->rf_path_num) - 1;
+	if (hal->ant_diversity) {
+		hw->wiphy->available_antennas_tx = 0x3;
+		hw->wiphy->available_antennas_rx = 0x3;
+	} else {
+		hw->wiphy->available_antennas_tx = BIT(rtwdev->chip->rf_path_num) - 1;
+		hw->wiphy->available_antennas_rx = BIT(rtwdev->chip->rf_path_num) - 1;
+	}
 
 	hw->wiphy->flags |= WIPHY_FLAG_SUPPORTS_TDLS |
 			    WIPHY_FLAG_TDLS_EXTERNAL_SETUP |

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

@@ -3423,6 +3423,8 @@ struct rtw89_hal {
 	u8 tx_nss;
 	u8 rx_nss;
 	bool tx_path_diversity;
+	bool ant_diversity;
+	bool ant_diversity_fixed;
 	bool support_cckpd;
 	bool support_igi;
 	atomic_t roc_entity_idx;

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

@@ -2598,6 +2598,7 @@ static int rtw89_mac_read_phycap(struct rtw89_dev *rtwdev,
 
 int rtw89_mac_setup_phycap(struct rtw89_dev *rtwdev)
 {
+	struct rtw89_efuse *efuse = &rtwdev->efuse;
 	struct rtw89_hal *hal = &rtwdev->hal;
 	const struct rtw89_chip_info *chip = rtwdev->chip;
 	struct rtw89_mac_c2h_info c2h_info = {0};
@@ -2629,6 +2630,13 @@ int rtw89_mac_setup_phycap(struct rtw89_dev *rtwdev)
 		hal->tx_path_diversity = true;
 	}
 
+	if (chip->rf_path_num == 1) {
+		hal->antenna_tx = RF_A;
+		hal->antenna_rx = RF_A;
+		if ((efuse->rfe_type % 3) == 2)
+			hal->ant_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,
@@ -2637,6 +2645,7 @@ int rtw89_mac_setup_phycap(struct rtw89_dev *rtwdev)
 		    "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);
+	rtw89_debug(rtwdev, RTW89_DBG_FW, "Antenna diversity=%d\n", hal->ant_diversity);
 
 	return 0;
 }

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

@@ -762,13 +762,18 @@ 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 && rx_ant != hal->antenna_rx)
+	if (hal->ant_diversity) {
+		if (tx_ant != rx_ant || hweight32(tx_ant) != 1)
+			return -EINVAL;
+	} else 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;
+	hal->ant_diversity_fixed = true;
 	mutex_unlock(&rtwdev->mutex);
 
 	return 0;