mt76: mt7603: check for single-stream EEPROM configuration

Some devices using MT7628 or MT7603 have only one antenna chain connected.
Detect these using the EEPROM rx/tx path settings
Reported-by: Qin Wei <me@vonger.cn>
Signed-off-by: Felix Fietkau <nbd@nbd.name>

drivers/net/wireless/mediatek/mt76/mt7603/eeprom.c

@@ -147,8 +147,14 @@ static int mt7603_check_eeprom(struct mt76_dev *dev)
 	}
 }
 
+static inline bool is_mt7688(struct mt7603_dev *dev)
+{
+	return mt76_rr(dev, MT_EFUSE_BASE + 0x64) & BIT(4);
+}
+
 int mt7603_eeprom_init(struct mt7603_dev *dev)
 {
+	u8 *eeprom;
 	int ret;
 
 	ret = mt7603_eeprom_load(dev);
@@ -163,9 +169,16 @@ int mt7603_eeprom_init(struct mt7603_dev *dev)
 			       MT7603_EEPROM_SIZE);
 	}
 
+	eeprom = (u8 *)dev->mt76.eeprom.data;
 	dev->mt76.cap.has_2ghz = true;
-	memcpy(dev->mt76.macaddr, dev->mt76.eeprom.data + MT_EE_MAC_ADDR,
-	       ETH_ALEN);
+	memcpy(dev->mt76.macaddr, eeprom + MT_EE_MAC_ADDR, ETH_ALEN);
+
+	/* Check for 1SS devices */
+	dev->mphy.antenna_mask = 3;
+	if (FIELD_GET(MT_EE_NIC_CONF_0_RX_PATH, eeprom[MT_EE_NIC_CONF_0]) == 1 ||
+	    FIELD_GET(MT_EE_NIC_CONF_0_TX_PATH, eeprom[MT_EE_NIC_CONF_0]) == 1 ||
+	    is_mt7688(dev))
+		dev->mphy.antenna_mask = 1;
 
 	mt76_eeprom_override(&dev->mt76);
 

drivers/net/wireless/mediatek/mt76/mt7603/eeprom.h

@@ -85,4 +85,7 @@ enum mt7603_eeprom_source {
 	MT_EE_SRC_FLASH,
 };
 
+#define MT_EE_NIC_CONF_0_RX_PATH		GENMASK(3, 0)
+#define MT_EE_NIC_CONF_0_TX_PATH		GENMASK(7, 4)
+
 #endif

drivers/net/wireless/mediatek/mt76/mt7603/init.c

@@ -536,11 +536,6 @@ int mt7603_register_device(struct mt7603_dev *dev)
 	tasklet_init(&dev->mt76.pre_tbtt_tasklet, mt7603_pre_tbtt_tasklet,
 		     (unsigned long)dev);
 
-	/* Check for 7688, which only has 1SS */
-	dev->mphy.antenna_mask = 3;
-	if (mt76_rr(dev, MT_EFUSE_BASE + 0x64) & BIT(4))
-		dev->mphy.antenna_mask = 1;
-
 	dev->slottime = 9;
 	dev->sensitivity_limit = 28;
 	dev->dynamic_sensitivity = true;