wifi: mt76: mt7925: introduce CSA support in non-MLO mode

Add CSA (Channel Switch Announcement) related implementation
in collaboration with mac80211 to deal with dynamic channel
switching.

Signed-off-by: Leon Yen <leon.yen@mediatek.com>
Signed-off-by: Ming Yen Hsieh <mingyen.hsieh@mediatek.com>
Link: https://patch.msgid.link/20250926053447.4036650-1-mingyen.hsieh@mediatek.com
Signed-off-by: Felix Fietkau <nbd@nbd.name>

3 files changed, 142 insertions, 3 deletions

diff --git a/drivers/net/wireless/mediatek/mt76/mt7925/main.c b/drivers/net/wireless/mediatek/mt76/mt7925/main.c
index 2d358a96640c..9861c1fde1ae 100644
--- a/drivers/net/wireless/mediatek/mt76/mt7925/main.c
+++ b/drivers/net/wireless/mediatek/mt76/mt7925/main.c
@@ -245,6 +245,7 @@ int mt7925_init_mlo_caps(struct mt792x_phy *phy)
 {
 	struct wiphy *wiphy = phy->mt76->hw->wiphy;
 	static const u8 ext_capa_sta[] = {
+		[0] = WLAN_EXT_CAPA1_EXT_CHANNEL_SWITCHING,
 		[2] = WLAN_EXT_CAPA3_MULTI_BSSID_SUPPORT,
 		[7] = WLAN_EXT_CAPA8_OPMODE_NOTIF,
 	};
@@ -438,6 +439,9 @@ mt7925_add_interface(struct ieee80211_hw *hw, struct ieee80211_vif *vif)
 	if (phy->chip_cap & MT792x_CHIP_CAP_RSSI_NOTIFY_EVT_EN)
 		vif->driver_flags |= IEEE80211_VIF_SUPPORTS_CQM_RSSI;
 
+	INIT_WORK(&mvif->csa_work, mt7925_csa_work);
+	timer_setup(&mvif->csa_timer, mt792x_csa_timer, 0);
+
 out:
 	mt792x_mutex_release(dev);
 
@@ -1749,6 +1753,10 @@ static int
 mt7925_add_chanctx(struct ieee80211_hw *hw,
 		   struct ieee80211_chanctx_conf *ctx)
 {
+	struct mt792x_dev *dev = mt792x_hw_dev(hw);
+
+	dev->new_ctx = ctx;
+
 	return 0;
 }
 
@@ -1756,6 +1764,11 @@ static void
 mt7925_remove_chanctx(struct ieee80211_hw *hw,
 		      struct ieee80211_chanctx_conf *ctx)
 {
+	struct mt792x_dev *dev = mt792x_hw_dev(hw);
+
+	if (dev->new_ctx == ctx)
+		dev->new_ctx = NULL;
+
 }
 
 static void
@@ -2144,6 +2157,11 @@ static void mt7925_unassign_vif_chanctx(struct ieee80211_hw *hw,
 	mctx->bss_conf = NULL;
 	mconf->mt76.ctx = NULL;
 	mutex_unlock(&dev->mt76.mutex);
+
+	if (link_conf->csa_active) {
+		timer_delete_sync(&mvif->csa_timer);
+		cancel_work_sync(&mvif->csa_work);
+	}
 }
 
 static void mt7925_rfkill_poll(struct ieee80211_hw *hw)
@@ -2158,6 +2176,121 @@ static void mt7925_rfkill_poll(struct ieee80211_hw *hw)
 	wiphy_rfkill_set_hw_state(hw->wiphy, ret == 0);
 }
 
+static int mt7925_switch_vif_chanctx(struct ieee80211_hw *hw,
+				     struct ieee80211_vif_chanctx_switch *vifs,
+				     int n_vifs,
+				     enum ieee80211_chanctx_switch_mode mode)
+{
+	return mt7925_assign_vif_chanctx(hw, vifs->vif, vifs->link_conf,
+					 vifs->new_ctx);
+}
+
+void mt7925_csa_work(struct work_struct *work)
+{
+	struct mt792x_vif *mvif;
+	struct mt792x_dev *dev;
+	struct ieee80211_vif *vif;
+	struct ieee80211_bss_conf *link_conf;
+	struct mt792x_bss_conf *mconf;
+	u8 link_id, roc_rtype;
+	int ret = 0;
+
+	mvif = (struct mt792x_vif *)container_of(work, struct mt792x_vif,
+						csa_work);
+	dev = mvif->phy->dev;
+	vif = container_of((void *)mvif, struct ieee80211_vif, drv_priv);
+
+	if (ieee80211_vif_is_mld(vif))
+		return;
+
+	if (!dev->new_ctx)
+		return;
+
+	link_id = 0;
+	mconf = &mvif->bss_conf;
+	link_conf = &vif->bss_conf;
+	roc_rtype = MT7925_ROC_REQ_JOIN;
+
+	mt792x_mutex_acquire(dev);
+	ret = mt7925_set_roc(mvif->phy, mconf, dev->new_ctx->def.chan,
+			     4000, roc_rtype);
+	mt792x_mutex_release(dev);
+	if (!ret) {
+		mt792x_mutex_acquire(dev);
+		ret = mt7925_mcu_set_chctx(mvif->phy->mt76, &mconf->mt76, link_conf,
+					   dev->new_ctx);
+		mt792x_mutex_release(dev);
+
+		mt7925_abort_roc(mvif->phy, mconf);
+	}
+
+	ieee80211_chswitch_done(vif, !ret, link_id);
+}
+
+static int mt7925_pre_channel_switch(struct ieee80211_hw *hw,
+				     struct ieee80211_vif *vif,
+				     struct ieee80211_channel_switch *chsw)
+{
+	if (ieee80211_vif_is_mld(vif))
+		return -EOPNOTSUPP;
+
+	if (vif->type != NL80211_IFTYPE_STATION || !vif->cfg.assoc)
+		return -EOPNOTSUPP;
+
+	if (!cfg80211_chandef_usable(hw->wiphy, &chsw->chandef,
+				     IEEE80211_CHAN_DISABLED))
+		return -EOPNOTSUPP;
+
+	return 0;
+}
+
+static void mt7925_channel_switch(struct ieee80211_hw *hw,
+				  struct ieee80211_vif *vif,
+				  struct ieee80211_channel_switch *chsw)
+{
+	struct mt792x_vif *mvif = (struct mt792x_vif *)vif->drv_priv;
+	u16 beacon_interval;
+
+	if (ieee80211_vif_is_mld(vif))
+		return;
+
+	beacon_interval = vif->bss_conf.beacon_int;
+
+	mvif->csa_timer.expires = TU_TO_EXP_TIME(beacon_interval * chsw->count);
+	add_timer(&mvif->csa_timer);
+}
+
+static void mt7925_abort_channel_switch(struct ieee80211_hw *hw,
+					struct ieee80211_vif *vif,
+					struct ieee80211_bss_conf *link_conf)
+{
+	struct mt792x_vif *mvif = (struct mt792x_vif *)vif->drv_priv;
+
+	timer_delete_sync(&mvif->csa_timer);
+	cancel_work_sync(&mvif->csa_work);
+}
+
+static void mt7925_channel_switch_rx_beacon(struct ieee80211_hw *hw,
+					    struct ieee80211_vif *vif,
+					    struct ieee80211_channel_switch *chsw)
+{
+	struct mt792x_dev *dev = mt792x_hw_dev(hw);
+	struct mt792x_vif *mvif = (struct mt792x_vif *)vif->drv_priv;
+	u16 beacon_interval;
+
+	if (ieee80211_vif_is_mld(vif))
+		return;
+
+	beacon_interval = vif->bss_conf.beacon_int;
+
+	if (cfg80211_chandef_identical(&chsw->chandef,
+				       &dev->new_ctx->def) &&
+				       chsw->count) {
+		mod_timer(&mvif->csa_timer,
+			  TU_TO_EXP_TIME(beacon_interval * chsw->count));
+	}
+}
+
 const struct ieee80211_ops mt7925_ops = {
 	.tx = mt792x_tx,
 	.start = mt7925_start,
@@ -2221,6 +2354,12 @@ const struct ieee80211_ops mt7925_ops = {
 	.change_vif_links = mt7925_change_vif_links,
 	.change_sta_links = mt7925_change_sta_links,
 	.rfkill_poll = mt7925_rfkill_poll,
+
+	.switch_vif_chanctx = mt7925_switch_vif_chanctx,
+	.pre_channel_switch = mt7925_pre_channel_switch,
+	.channel_switch = mt7925_channel_switch,
+	.abort_channel_switch = mt7925_abort_channel_switch,
+	.channel_switch_rx_beacon = mt7925_channel_switch_rx_beacon,
 };
 EXPORT_SYMBOL_GPL(mt7925_ops);
 
diff --git a/drivers/net/wireless/mediatek/mt76/mt7925/mt7925.h b/drivers/net/wireless/mediatek/mt76/mt7925/mt7925.h
index 6b9bf1b89032..5030d7714bcf 100644
--- a/drivers/net/wireless/mediatek/mt76/mt7925/mt7925.h
+++ b/drivers/net/wireless/mediatek/mt76/mt7925/mt7925.h
@@ -298,6 +298,7 @@ int mt7925_mcu_uni_rx_ba(struct mt792x_dev *dev,
 void mt7925_mlo_pm_work(struct work_struct *work);
 void mt7925_scan_work(struct work_struct *work);
 void mt7925_roc_work(struct work_struct *work);
+void mt7925_csa_work(struct work_struct *work);
 int mt7925_mcu_uni_bss_ps(struct mt792x_dev *dev,
 			  struct ieee80211_bss_conf *link_conf);
 void mt7925_coredump_work(struct work_struct *work);
diff --git a/drivers/net/wireless/mediatek/mt76/mt792x_core.c b/drivers/net/wireless/mediatek/mt76/mt792x_core.c
index f2ed16feb6c1..f318a53e4deb 100644
--- a/drivers/net/wireless/mediatek/mt76/mt792x_core.c
+++ b/drivers/net/wireless/mediatek/mt76/mt792x_core.c
@@ -691,9 +691,8 @@ int mt792x_init_wiphy(struct ieee80211_hw *hw)
 	ieee80211_hw_set(hw, SUPPORTS_MULTI_BSSID);
 	ieee80211_hw_set(hw, SUPPORTS_ONLY_HE_MULTI_BSSID);
 
-	if (is_mt7921(&dev->mt76)) {
-		ieee80211_hw_set(hw, CHANCTX_STA_CSA);
-	}
+	ieee80211_hw_set(hw, CHANCTX_STA_CSA);
+
 
 	if (dev->pm.enable)
 		ieee80211_hw_set(hw, CONNECTION_MONITOR);