mt76: mt7915: introduce __mt7915_get_tsf routine

Introduce an unlocked verion of mt7915_get_tsf routine.
This is a preliminary patch to add TWT support to mt7915.
Tested-by: Peter Chiu <chui-hao.chiu@mediatek.com>
Tested-by: Evelyn Tsai <evelyn.tsai@mediatek.com>
Signed-off-by: Lorenzo Bianconi <lorenzo@kernel.org>
Signed-off-by: Felix Fietkau <nbd@nbd.name>

drivers/net/wireless/mediatek/mt76/mt7915/main.c

@@ -819,10 +819,8 @@ mt7915_get_stats(struct ieee80211_hw *hw,
 	return 0;
 }
 
-static u64
-mt7915_get_tsf(struct ieee80211_hw *hw, struct ieee80211_vif *vif)
+u64 __mt7915_get_tsf(struct ieee80211_hw *hw, struct mt7915_vif *mvif)
 {
-	struct mt7915_vif *mvif = (struct mt7915_vif *)vif->drv_priv;
 	struct mt7915_dev *dev = mt7915_hw_dev(hw);
 	struct mt7915_phy *phy = mt7915_hw_phy(hw);
 	bool band = phy != &dev->phy;
@@ -832,7 +830,7 @@ mt7915_get_tsf(struct ieee80211_hw *hw, struct ieee80211_vif *vif)
 	} tsf;
 	u16 n;
 
-	mutex_lock(&dev->mt76.mutex);
+	lockdep_assert_held(&dev->mt76.mutex);
 
 	n = mvif->omac_idx > HW_BSSID_MAX ? HW_BSSID_0 : mvif->omac_idx;
 	/* TSF software read */
@@ -841,9 +839,21 @@ mt7915_get_tsf(struct ieee80211_hw *hw, struct ieee80211_vif *vif)
 	tsf.t32[0] = mt76_rr(dev, MT_LPON_UTTR0(band));
 	tsf.t32[1] = mt76_rr(dev, MT_LPON_UTTR1(band));
 
+	return tsf.t64;
+}
+
+static u64
+mt7915_get_tsf(struct ieee80211_hw *hw, struct ieee80211_vif *vif)
+{
+	struct mt7915_vif *mvif = (struct mt7915_vif *)vif->drv_priv;
+	struct mt7915_dev *dev = mt7915_hw_dev(hw);
+	u64 ret;
+
+	mutex_lock(&dev->mt76.mutex);
+	ret = __mt7915_get_tsf(hw, mvif);
 	mutex_unlock(&dev->mt76.mutex);
 
-	return tsf.t64;
+	return ret;
 }
 
 static void

drivers/net/wireless/mediatek/mt76/mt7915/mt7915.h

@@ -329,7 +329,7 @@ extern const struct ieee80211_ops mt7915_ops;
 extern const struct mt76_testmode_ops mt7915_testmode_ops;
 
 u32 mt7915_reg_map(struct mt7915_dev *dev, u32 addr);
-
+u64 __mt7915_get_tsf(struct ieee80211_hw *hw, struct mt7915_vif *mvif);
 int mt7915_register_device(struct mt7915_dev *dev);
 void mt7915_unregister_device(struct mt7915_dev *dev);
 int mt7915_eeprom_init(struct mt7915_dev *dev);