mt76: mt7921: introduce PM support

Introduce suspend/resume and WoW (Wake-on-WoWLAN) support to mt7921
driver to allow remote wakeu-up from the suspend state.

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

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

@@ -966,6 +966,79 @@ static void mt7921_sta_statistics(struct ieee80211_hw *hw,
 	sinfo->filled |= BIT_ULL(NL80211_STA_INFO_TX_BITRATE);
 }
 
+#ifdef CONFIG_PM
+static int mt7921_suspend(struct ieee80211_hw *hw,
+			  struct cfg80211_wowlan *wowlan)
+{
+	struct mt7921_dev *dev = mt7921_hw_dev(hw);
+	struct mt7921_phy *phy = mt7921_hw_phy(hw);
+	int err;
+
+	cancel_delayed_work_sync(&phy->scan_work);
+	cancel_delayed_work_sync(&phy->mt76->mac_work);
+
+	mutex_lock(&dev->mt76.mutex);
+
+	clear_bit(MT76_STATE_RUNNING, &phy->mt76->state);
+
+	set_bit(MT76_STATE_SUSPEND, &phy->mt76->state);
+	ieee80211_iterate_active_interfaces(hw,
+					    IEEE80211_IFACE_ITER_RESUME_ALL,
+					    mt7921_mcu_set_suspend_iter, phy);
+
+	err = mt7921_mcu_set_hif_suspend(dev, true);
+
+	mutex_unlock(&dev->mt76.mutex);
+
+	return err;
+}
+
+static int mt7921_resume(struct ieee80211_hw *hw)
+{
+	struct mt7921_dev *dev = mt7921_hw_dev(hw);
+	struct mt7921_phy *phy = mt7921_hw_phy(hw);
+	int err;
+
+	mutex_lock(&dev->mt76.mutex);
+
+	err = mt7921_mcu_set_hif_suspend(dev, false);
+	if (err < 0)
+		goto out;
+
+	set_bit(MT76_STATE_RUNNING, &phy->mt76->state);
+	clear_bit(MT76_STATE_SUSPEND, &phy->mt76->state);
+	ieee80211_iterate_active_interfaces(hw,
+					    IEEE80211_IFACE_ITER_RESUME_ALL,
+					    mt7921_mcu_set_suspend_iter, phy);
+
+	ieee80211_queue_delayed_work(hw, &phy->mt76->mac_work,
+				     MT7921_WATCHDOG_TIME);
+out:
+	mutex_unlock(&dev->mt76.mutex);
+
+	return err;
+}
+
+static void mt7921_set_wakeup(struct ieee80211_hw *hw, bool enabled)
+{
+	struct mt7921_dev *dev = mt7921_hw_dev(hw);
+	struct mt76_dev *mdev = &dev->mt76;
+
+	device_set_wakeup_enable(mdev->dev, enabled);
+}
+
+static void mt7921_set_rekey_data(struct ieee80211_hw *hw,
+				  struct ieee80211_vif *vif,
+				  struct cfg80211_gtk_rekey_data *data)
+{
+	struct mt7921_dev *dev = mt7921_hw_dev(hw);
+
+	mutex_lock(&dev->mt76.mutex);
+	mt7921_mcu_update_gtk_rekey(hw, vif, data);
+	mutex_unlock(&dev->mt76.mutex);
+}
+#endif /* CONFIG_PM */
+
 const struct ieee80211_ops mt7921_ops = {
 	.tx = mt7921_tx,
 	.start = mt7921_start,
@@ -998,4 +1071,10 @@ const struct ieee80211_ops mt7921_ops = {
 	.sta_statistics = mt7921_sta_statistics,
 	.sched_scan_start = mt7921_start_sched_scan,
 	.sched_scan_stop = mt7921_stop_sched_scan,
+#ifdef CONFIG_PM
+	.suspend = mt7921_suspend,
+	.resume = mt7921_resume,
+	.set_wakeup = mt7921_set_wakeup,
+	.set_rekey_data = mt7921_set_rekey_data,
+#endif /* CONFIG_PM */
 };