mt76: mt7921: introduce regdomain notifier support

Register regdomain notifier to determine the channel domain the hw scan
should rely on.

Co-developed-by: Sean Wang <sean.wang@mediatek.com>
Signed-off-by: Sean Wang <sean.wang@mediatek.com>
Signed-off-by: Lorenzo Bianconi <lorenzo@kernel.org>
Signed-off-by: Felix Fietkau <nbd@nbd.name>

drivers/net/wireless/mediatek/mt76/mt7921/init.c

@@ -52,6 +52,21 @@ static const struct ieee80211_iface_combination if_comb[] = {
 	}
 };
 
+static void
+mt7921_regd_notifier(struct wiphy *wiphy,
+		     struct regulatory_request *request)
+{
+	struct ieee80211_hw *hw = wiphy_to_ieee80211_hw(wiphy);
+	struct mt7921_dev *dev = mt7921_hw_dev(hw);
+
+	memcpy(dev->mt76.alpha2, request->alpha2, sizeof(dev->mt76.alpha2));
+	dev->mt76.region = request->dfs_region;
+
+	mt7921_mutex_acquire(dev);
+	mt76_connac_mcu_set_channel_domain(hw->priv);
+	mt7921_mutex_release(dev);
+}
+
 static void
 mt7921_init_wiphy(struct ieee80211_hw *hw)
 {
@@ -78,6 +93,7 @@ mt7921_init_wiphy(struct ieee80211_hw *hw)
 	wiphy->max_match_sets = MT76_CONNAC_MAX_SCAN_MATCH;
 	wiphy->max_sched_scan_reqs = 1;
 	wiphy->flags |= WIPHY_FLAG_HAS_CHANNEL_SWITCH;
+	wiphy->reg_notifier = mt7921_regd_notifier;
 
 	wiphy_ext_feature_set(wiphy, NL80211_EXT_FEATURE_SET_SCAN_DWELL);