rtl8xxxu: feed antenna information for cfg80211

Fill up the available TX/RX antenna so the iw commands can show
correct antenna information for different chips.
Signed-off-by: Chris Chiu <chris.chiu@canonical.com>
Signed-off-by: Kalle Valo <kvalo@kernel.org>
Link: https://lore.kernel.org/r/20220325035735.4745-2-chris.chiu@canonical.com

drivers/net/wireless/realtek/rtl8xxxu/rtl8xxxu_core.c

@@ -1607,6 +1607,7 @@ static void rtl8xxxu_print_chipinfo(struct rtl8xxxu_priv *priv)
 static int rtl8xxxu_identify_chip(struct rtl8xxxu_priv *priv)
 {
 	struct device *dev = &priv->udev->dev;
+	struct ieee80211_hw *hw = priv->hw;
 	u32 val32, bonding;
 	u16 val16;
 
@@ -1684,6 +1685,9 @@ static int rtl8xxxu_identify_chip(struct rtl8xxxu_priv *priv)
 		priv->has_wifi = 1;
 	}
 
+	hw->wiphy->available_antennas_tx = BIT(priv->tx_paths) - 1;
+	hw->wiphy->available_antennas_rx = BIT(priv->rx_paths) - 1;
+
 	switch (priv->rtl_chip) {
 	case RTL8188E:
 	case RTL8192E:
@@ -4282,6 +4286,17 @@ static void rtl8xxxu_cam_write(struct rtl8xxxu_priv *priv,
 	rtl8xxxu_debug = tmp_debug;
 }
 
+static
+int rtl8xxxu_get_antenna(struct ieee80211_hw *hw, u32 *tx_ant, u32 *rx_ant)
+{
+	struct rtl8xxxu_priv *priv = hw->priv;
+
+	*tx_ant = BIT(priv->tx_paths) - 1;
+	*rx_ant = BIT(priv->rx_paths) - 1;
+
+	return 0;
+}
+
 static void rtl8xxxu_sw_scan_start(struct ieee80211_hw *hw,
 				   struct ieee80211_vif *vif, const u8 *mac)
 {
@@ -6472,6 +6487,7 @@ static const struct ieee80211_ops rtl8xxxu_ops = {
 	.set_key = rtl8xxxu_set_key,
 	.ampdu_action = rtl8xxxu_ampdu_action,
 	.sta_statistics = rtl8xxxu_sta_statistics,
+	.get_antenna = rtl8xxxu_get_antenna,
 };
 
 static int rtl8xxxu_parse_usb(struct rtl8xxxu_priv *priv,