[PATCH v2 6/7] mt76: mt7915: fix eeprom parsing for DBDC

[Felix Fietkau <nbd@nbd.name>]

Annotate WIFI_CONF eeprom mask values with the byte number
Fix parsing per-band number of chains

Signed-off-by: Felix Fietkau <nbd@nbd.name>
---
v2: detect faulty eeprom path settings that worked before this patch

 .../wireless/mediatek/mt76/mt7915/eeprom.c    | 28 +++++++++++--------
 .../wireless/mediatek/mt76/mt7915/eeprom.h    | 17 ++++++-----
 2 files changed, 26 insertions(+), 19 deletions(-)

diff --git a/drivers/net/wireless/mediatek/mt76/mt7915/eeprom.c b/drivers/net/wireless/mediatek/mt76/mt7915/eeprom.c
index 7807b9165e01..291a781dada2 100644
--- a/drivers/net/wireless/mediatek/mt76/mt7915/eeprom.c
+++ b/drivers/net/wireless/mediatek/mt76/mt7915/eeprom.c
@@ -53,7 +53,7 @@ void mt7915_eeprom_parse_band_config(struct mt7915_phy *phy)
 	u32 val;
 
 	val = mt7915_eeprom_read(dev, MT_EE_WIFI_CONF + ext_phy);
-	val = FIELD_GET(MT_EE_WIFI_CONF_BAND_SEL, val);
+	val = FIELD_GET(MT_EE_WIFI_CONF0_BAND_SEL, val);
 	switch (val) {
 	case MT_EE_5GHZ:
 		phy->mt76->cap.has_5ghz = true;
@@ -70,25 +70,29 @@ void mt7915_eeprom_parse_band_config(struct mt7915_phy *phy)
 
 static void mt7915_eeprom_parse_hw_cap(struct mt7915_dev *dev)
 {
-	u8 nss, tx_mask[2] = {}, *eeprom = dev->mt76.eeprom.data;
+	u8 nss, nss_band, *eeprom = dev->mt76.eeprom.data;
 
 	mt7915_eeprom_parse_band_config(&dev->phy);
 
 	/* read tx mask from eeprom */
-	tx_mask[0] = FIELD_GET(MT_EE_WIFI_CONF_TX_MASK,
-			       eeprom[MT_EE_WIFI_CONF]);
-	if (dev->dbdc_support)
-		tx_mask[1] = FIELD_GET(MT_EE_WIFI_CONF_TX_MASK,
-				       eeprom[MT_EE_WIFI_CONF + 1]);
-
-	nss = tx_mask[0] + tx_mask[1];
-	if (!nss || nss > 4) {
-		tx_mask[0] = 4;
+	nss = FIELD_GET(MT_EE_WIFI_CONF0_TX_PATH, eeprom[MT_EE_WIFI_CONF]);
+	if (!nss || nss > 4)
 		nss = 4;
+
+	nss_band = nss;
+
+	if (dev->dbdc_support) {
+		nss_band = FIELD_GET(MT_EE_WIFI_CONF3_TX_PATH_B0,
+				     eeprom[MT_EE_WIFI_CONF + 3]);
+		if (!nss_band || nss_band > 2)
+			nss_band = 2;
+
+		if (nss_band >= nss)
+			nss = 4;
 	}
 
 	dev->chainmask = BIT(nss) - 1;
-	dev->mphy.antenna_mask = BIT(tx_mask[0]) - 1;
+	dev->mphy.antenna_mask = BIT(nss_band) - 1;
 	dev->mphy.chainmask = dev->mphy.antenna_mask;
 }
 
diff --git a/drivers/net/wireless/mediatek/mt76/mt7915/eeprom.h b/drivers/net/wireless/mediatek/mt76/mt7915/eeprom.h
index 6712032b40df..7999e95560a8 100644
--- a/drivers/net/wireless/mediatek/mt76/mt7915/eeprom.h
+++ b/drivers/net/wireless/mediatek/mt76/mt7915/eeprom.h
@@ -25,11 +25,14 @@ enum mt7915_eeprom_field {
 	__MT_EE_MAX =		0xe00
 };
 
-#define MT_EE_WIFI_CONF_TX_MASK			GENMASK(2, 0)
-#define MT_EE_WIFI_CONF_BAND_SEL		GENMASK(7, 6)
-#define MT_EE_WIFI_CONF_TSSI0_2G		BIT(0)
-#define MT_EE_WIFI_CONF_TSSI0_5G		BIT(2)
-#define MT_EE_WIFI_CONF_TSSI1_5G		BIT(4)
+#define MT_EE_WIFI_CONF0_TX_PATH		GENMASK(2, 0)
+#define MT_EE_WIFI_CONF0_BAND_SEL		GENMASK(7, 6)
+#define MT_EE_WIFI_CONF1_BAND_SEL		GENMASK(7, 6)
+#define MT_EE_WIFI_CONF3_TX_PATH_B0		GENMASK(1, 0)
+#define MT_EE_WIFI_CONF3_TX_PATH_B1		GENMASK(5, 4)
+#define MT_EE_WIFI_CONF7_TSSI0_2G		BIT(0)
+#define MT_EE_WIFI_CONF7_TSSI0_5G		BIT(2)
+#define MT_EE_WIFI_CONF7_TSSI1_5G		BIT(4)
 
 enum mt7915_eeprom_band {
 	MT_EE_DUAL_BAND,
@@ -116,9 +119,9 @@ mt7915_tssi_enabled(struct mt7915_dev *dev, enum nl80211_band band)
 
 	/* TODO: DBDC */
 	if (band == NL80211_BAND_5GHZ)
-		return eep[MT_EE_WIFI_CONF + 7] & MT_EE_WIFI_CONF_TSSI0_5G;
+		return eep[MT_EE_WIFI_CONF + 7] & MT_EE_WIFI_CONF7_TSSI0_5G;
 	else
-		return eep[MT_EE_WIFI_CONF + 7] & MT_EE_WIFI_CONF_TSSI0_2G;
+		return eep[MT_EE_WIFI_CONF + 7] & MT_EE_WIFI_CONF7_TSSI0_2G;
 }
 
 extern const struct sku_group mt7915_sku_groups[];
-- 
2.28.0