ath11k: Implement remain-on-channel support

Add remain on channel support, it is needed in several
scenarios such as Passpoint etc.

Currently this is supported by QCA6390, WCN6855, IPQ8074,
IPQ6018 and QCN9074.

Tested-on: WCN6855 hw2.0 PCI WLAN.HSP.1.1-01720.1-QCAHSPSWPL_V1_V2_SILICONZ_LITE-1
Signed-off-by: Baochen Qiang <quic_bqiang@quicinc.com>
Signed-off-by: Kalle Valo <quic_kvalo@quicinc.com>
Link: https://lore.kernel.org/r/20220506013614.1580274-2-quic_bqiang@quicinc.com

drivers/net/wireless/ath/ath11k/core.c

@@ -1624,6 +1624,7 @@ static void ath11k_core_pre_reconfigure_recovery(struct ath11k_base *ab)
 		complete(&ar->completed_11d_scan);
 		complete(&ar->scan.started);
 		complete(&ar->scan.completed);
+		complete(&ar->scan.on_channel);
 		complete(&ar->peer_assoc_done);
 		complete(&ar->peer_delete_done);
 		complete(&ar->install_key_done);

drivers/net/wireless/ath/ath11k/mac.c

@@ -8354,6 +8354,118 @@ static int ath11k_mac_op_set_bios_sar_specs(struct ieee80211_hw *hw,
 	return ret;
 }
 
+static int ath11k_mac_op_cancel_remain_on_channel(struct ieee80211_hw *hw,
+						  struct ieee80211_vif *vif)
+{
+	struct ath11k *ar = hw->priv;
+
+	mutex_lock(&ar->conf_mutex);
+
+	spin_lock_bh(&ar->data_lock);
+	ar->scan.roc_notify = false;
+	spin_unlock_bh(&ar->data_lock);
+
+	ath11k_scan_abort(ar);
+
+	mutex_unlock(&ar->conf_mutex);
+
+	cancel_delayed_work_sync(&ar->scan.timeout);
+
+	return 0;
+}
+
+static int ath11k_mac_op_remain_on_channel(struct ieee80211_hw *hw,
+					   struct ieee80211_vif *vif,
+					   struct ieee80211_channel *chan,
+					   int duration,
+					   enum ieee80211_roc_type type)
+{
+	struct ath11k *ar = hw->priv;
+	struct ath11k_vif *arvif = (void *)vif->drv_priv;
+	struct scan_req_params arg;
+	int ret;
+	u32 scan_time_msec;
+
+	mutex_lock(&ar->conf_mutex);
+
+	spin_lock_bh(&ar->data_lock);
+	switch (ar->scan.state) {
+	case ATH11K_SCAN_IDLE:
+		reinit_completion(&ar->scan.started);
+		reinit_completion(&ar->scan.completed);
+		reinit_completion(&ar->scan.on_channel);
+		ar->scan.state = ATH11K_SCAN_STARTING;
+		ar->scan.is_roc = true;
+		ar->scan.vdev_id = arvif->vdev_id;
+		ar->scan.roc_freq = chan->center_freq;
+		ar->scan.roc_notify = true;
+		ret = 0;
+		break;
+	case ATH11K_SCAN_STARTING:
+	case ATH11K_SCAN_RUNNING:
+	case ATH11K_SCAN_ABORTING:
+		ret = -EBUSY;
+		break;
+	}
+	spin_unlock_bh(&ar->data_lock);
+
+	if (ret)
+		goto exit;
+
+	scan_time_msec = ar->hw->wiphy->max_remain_on_channel_duration * 2;
+
+	memset(&arg, 0, sizeof(arg));
+	ath11k_wmi_start_scan_init(ar, &arg);
+	arg.num_chan = 1;
+	arg.chan_list = kcalloc(arg.num_chan, sizeof(*arg.chan_list),
+				GFP_KERNEL);
+	if (!arg.chan_list) {
+		ret = -ENOMEM;
+		goto exit;
+	}
+
+	arg.vdev_id = arvif->vdev_id;
+	arg.scan_id = ATH11K_SCAN_ID;
+	arg.chan_list[0] = chan->center_freq;
+	arg.dwell_time_active = scan_time_msec;
+	arg.dwell_time_passive = scan_time_msec;
+	arg.max_scan_time = scan_time_msec;
+	arg.scan_flags |= WMI_SCAN_FLAG_PASSIVE;
+	arg.scan_flags |= WMI_SCAN_FILTER_PROBE_REQ;
+	arg.burst_duration = duration;
+
+	ret = ath11k_start_scan(ar, &arg);
+	if (ret) {
+		ath11k_warn(ar->ab, "failed to start roc scan: %d\n", ret);
+
+		spin_lock_bh(&ar->data_lock);
+		ar->scan.state = ATH11K_SCAN_IDLE;
+		spin_unlock_bh(&ar->data_lock);
+		goto free_chan_list;
+	}
+
+	ret = wait_for_completion_timeout(&ar->scan.on_channel, 3 * HZ);
+	if (ret == 0) {
+		ath11k_warn(ar->ab, "failed to switch to channel for roc scan\n");
+		ret = ath11k_scan_stop(ar);
+		if (ret)
+			ath11k_warn(ar->ab, "failed to stop scan: %d\n", ret);
+		ret = -ETIMEDOUT;
+		goto free_chan_list;
+	}
+
+	ieee80211_queue_delayed_work(ar->hw, &ar->scan.timeout,
+				     msecs_to_jiffies(duration));
+
+	ret = 0;
+
+free_chan_list:
+	kfree(arg.chan_list);
+exit:
+	mutex_unlock(&ar->conf_mutex);
+	return ret;
+}
+
 static const struct ieee80211_ops ath11k_ops = {
 	.tx				= ath11k_mac_op_tx,
 	.start                          = ath11k_mac_op_start,
@@ -8406,6 +8518,8 @@ static const struct ieee80211_ops ath11k_ops = {
 #endif
 
 	.set_sar_specs			= ath11k_mac_op_set_bios_sar_specs,
+	.remain_on_channel		= ath11k_mac_op_remain_on_channel,
+	.cancel_remain_on_channel	= ath11k_mac_op_cancel_remain_on_channel,
 };
 
 static void ath11k_mac_update_ch_list(struct ath11k *ar,
@@ -8995,6 +9109,7 @@ int ath11k_mac_allocate(struct ath11k_base *ab)
 		init_completion(&ar->bss_survey_done);
 		init_completion(&ar->scan.started);
 		init_completion(&ar->scan.completed);
+		init_completion(&ar->scan.on_channel);
 		init_completion(&ar->thermal.wmi_sync);
 
 		INIT_DELAYED_WORK(&ar->scan.timeout, ath11k_scan_timeout_work);

drivers/net/wireless/ath/ath11k/wmi.c

@@ -5264,6 +5264,8 @@ static void ath11k_wmi_event_scan_started(struct ath11k *ar)
 		break;
 	case ATH11K_SCAN_STARTING:
 		ar->scan.state = ATH11K_SCAN_RUNNING;
+		if (ar->scan.is_roc)
+			ieee80211_ready_on_channel(ar->hw);
 		complete(&ar->scan.started);
 		break;
 	}
@@ -5346,6 +5348,8 @@ static void ath11k_wmi_event_scan_foreign_chan(struct ath11k *ar, u32 freq)
 	case ATH11K_SCAN_RUNNING:
 	case ATH11K_SCAN_ABORTING:
 		ar->scan_channel = ieee80211_get_channel(ar->hw->wiphy, freq);
+		if (ar->scan.is_roc && ar->scan.roc_freq == freq)
+			complete(&ar->scan.on_channel);
 		break;
 	}
 }