[PATCH v9 04/21] wifi: nxpwifi: add support for 802.11h (DFS and TPC)

[Jeff Chen <jeff.chen_1@nxp.com>]

Introduce 802.11h functionality to the nxpwifi driver, enabling
Dynamic Frequency Selection (DFS) and Transmit Power Control (TPC)
features required for regulatory compliance in 5GHz bands.

- Adds logic to handle DFS CAC (Channel Availability Check) procedures,
  including radar detection, CAC timeout, and abort handling.
- Implements firmware interaction via HOST_CMD_CHAN_REPORT_REQUEST
  and radar event handling.
- Supports TPC through power capability and local power constraint IEs
  during association.
- Enables channel switch operations with AP restart and beacon updates.

Firmware is responsible for radar detection and reporting, while the
driver manages TLV construction, event handling, and cfg80211 integration.

Signed-off-by: Jeff Chen <jeff.chen_1@nxp.com>
---
 drivers/net/wireless/nxp/nxpwifi/11h.c | 338 +++++++++++++++++++++++++
 1 file changed, 338 insertions(+)
 create mode 100644 drivers/net/wireless/nxp/nxpwifi/11h.c

diff --git a/drivers/net/wireless/nxp/nxpwifi/11h.c b/drivers/net/wireless/nxp/nxpwifi/11h.c
new file mode 100644
index 000000000000..2189b5242fc9
--- /dev/null
+++ b/drivers/net/wireless/nxp/nxpwifi/11h.c
@@ -0,0 +1,338 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * nxpwifi: 802.11h helpers
+ *
+ * Copyright 2011-2024 NXP
+ */
+
+#include "main.h"
+#include "cmdevt.h"
+#include "fw.h"
+#include "cfg80211.h"
+
+void nxpwifi_init_11h_params(struct nxpwifi_private *priv)
+{
+	priv->state_11h.is_11h_enabled = true;
+	priv->state_11h.is_11h_active = false;
+}
+
+inline int nxpwifi_is_11h_active(struct nxpwifi_private *priv)
+{
+	return priv->state_11h.is_11h_active;
+}
+
+/* appends 11h info to a buffer while joining an infrastructure BSS */
+static void
+nxpwifi_11h_process_infra_join(struct nxpwifi_private *priv, u8 **buffer,
+			       struct nxpwifi_bssdescriptor *bss_desc)
+{
+	struct nxpwifi_ie_types_header *ie_header;
+	struct nxpwifi_ie_types_pwr_capability *cap;
+	struct nxpwifi_ie_types_local_pwr_constraint *constraint;
+	struct ieee80211_supported_band *sband;
+	u8 radio_type;
+	int i;
+
+	if (!buffer || !(*buffer))
+		return;
+
+	radio_type = nxpwifi_band_to_radio_type((u8)bss_desc->bss_band);
+	sband = priv->wdev.wiphy->bands[radio_type];
+
+	cap = (struct nxpwifi_ie_types_pwr_capability *)*buffer;
+	cap->header.type = cpu_to_le16(WLAN_EID_PWR_CAPABILITY);
+	cap->header.len = cpu_to_le16(2);
+	cap->min_pwr = 0;
+	cap->max_pwr = 0;
+	*buffer += sizeof(*cap);
+
+	constraint = (struct nxpwifi_ie_types_local_pwr_constraint *)*buffer;
+	constraint->header.type = cpu_to_le16(WLAN_EID_PWR_CONSTRAINT);
+	constraint->header.len = cpu_to_le16(2);
+	constraint->chan = bss_desc->channel;
+	constraint->constraint = bss_desc->local_constraint;
+	*buffer += sizeof(*constraint);
+
+	ie_header = (struct nxpwifi_ie_types_header *)*buffer;
+	ie_header->type = cpu_to_le16(TLV_TYPE_PASSTHROUGH);
+	ie_header->len  = cpu_to_le16(2 * sband->n_channels + 2);
+	*buffer += sizeof(*ie_header);
+	*(*buffer)++ = WLAN_EID_SUPPORTED_CHANNELS;
+	*(*buffer)++ = 2 * sband->n_channels;
+	for (i = 0; i < sband->n_channels; i++) {
+		u32 center_freq;
+
+		center_freq = sband->channels[i].center_freq;
+		*(*buffer)++ = ieee80211_frequency_to_channel(center_freq);
+		*(*buffer)++ = 1; /* one channel in the subband */
+	}
+}
+
+/* Enable or disable the 11h extensions in the firmware */
+int nxpwifi_11h_activate(struct nxpwifi_private *priv, bool flag)
+{
+	u32 enable = flag;
+
+	/* enable master mode radar detection on AP interface */
+	if ((GET_BSS_ROLE(priv) == NXPWIFI_BSS_ROLE_UAP) && enable)
+		enable |= NXPWIFI_MASTER_RADAR_DET_MASK;
+
+	return nxpwifi_send_cmd(priv, HOST_CMD_802_11_SNMP_MIB,
+				HOST_ACT_GEN_SET, DOT11H_I, &enable, true);
+}
+
+/*
+ * Process TLV buffer for a pending BSS join. Enable 11h in firmware when the
+ * network advertises spectrum management, and add required TLVs based on the
+ * BSS's 11h capability.
+ */
+void nxpwifi_11h_process_join(struct nxpwifi_private *priv, u8 **buffer,
+			      struct nxpwifi_bssdescriptor *bss_desc)
+{
+	if (bss_desc->sensed_11h) {
+		/* Activate 11h functions in firmware, turns on capability bit */
+		nxpwifi_11h_activate(priv, true);
+		priv->state_11h.is_11h_active = true;
+		bss_desc->cap_info_bitmap |= WLAN_CAPABILITY_SPECTRUM_MGMT;
+		nxpwifi_11h_process_infra_join(priv, buffer, bss_desc);
+	} else {
+		/* Deactivate 11h functions in the firmware */
+		nxpwifi_11h_activate(priv, false);
+		priv->state_11h.is_11h_active = false;
+		bss_desc->cap_info_bitmap &= ~WLAN_CAPABILITY_SPECTRUM_MGMT;
+	}
+}
+
+/*
+ * DFS CAC work function. This delayed work emits CAC finished event for cfg80211
+ * if CAC was started earlier
+ */
+void nxpwifi_dfs_cac_work(struct wiphy *wiphy, struct wiphy_work *work)
+{
+	struct cfg80211_chan_def chandef;
+	struct wiphy_delayed_work *delayed_work =
+		container_of(work, struct wiphy_delayed_work, work);
+	struct nxpwifi_private *priv = container_of(delayed_work,
+						    struct nxpwifi_private,
+						    dfs_cac_work);
+
+	chandef = priv->dfs_chandef;
+	if (priv->wdev.links[0].cac_started) {
+		nxpwifi_dbg(priv->adapter, MSG,
+			    "CAC timer finished; No radar detected\n");
+		cfg80211_cac_event(priv->netdev, &chandef,
+				   NL80211_RADAR_CAC_FINISHED,
+				   GFP_KERNEL, 0);
+	}
+}
+
+/* prepares channel report request command to FW for starting radar detection */
+int nxpwifi_cmd_issue_chan_report_request(struct nxpwifi_private *priv,
+					  struct host_cmd_ds_command *cmd,
+					  void *data_buf)
+{
+	struct host_cmd_ds_chan_rpt_req *cr_req = &cmd->params.chan_rpt_req;
+	struct nxpwifi_radar_params *radar_params = (void *)data_buf;
+	u16 size;
+
+	cmd->command = cpu_to_le16(HOST_CMD_CHAN_REPORT_REQUEST);
+	size = S_DS_GEN;
+
+	cr_req->chan_desc.start_freq = cpu_to_le16(NXPWIFI_A_BAND_START_FREQ);
+	nxpwifi_convert_chan_to_band_cfg(priv,
+					 &cr_req->chan_desc.band_cfg,
+					 radar_params->chandef);
+	cr_req->chan_desc.chan_num = radar_params->chandef->chan->hw_value;
+	cr_req->msec_dwell_time = cpu_to_le32(radar_params->cac_time_ms);
+	size += sizeof(*cr_req);
+
+	if (radar_params->cac_time_ms) {
+		struct nxpwifi_ie_types_chan_rpt_data *rpt;
+
+		rpt = (struct nxpwifi_ie_types_chan_rpt_data *)((u8 *)cmd + size);
+		rpt->header.type = cpu_to_le16(TLV_TYPE_CHANRPT_11H_BASIC);
+		rpt->header.len = cpu_to_le16(sizeof(u8));
+		rpt->meas_rpt_map = 1 << MEAS_RPT_MAP_RADAR_SHIFT_BIT;
+		size += sizeof(*rpt);
+
+		nxpwifi_dbg(priv->adapter, MSG,
+			    "11h: issuing DFS Radar check for channel=%d\n",
+			    radar_params->chandef->chan->hw_value);
+	} else {
+		nxpwifi_dbg(priv->adapter, MSG, "cancelling CAC\n");
+	}
+
+	cmd->size = cpu_to_le16(size);
+
+	return 0;
+}
+
+int nxpwifi_stop_radar_detection(struct nxpwifi_private *priv,
+				 struct cfg80211_chan_def *chandef)
+{
+	struct nxpwifi_radar_params radar_params;
+
+	memset(&radar_params, 0, sizeof(struct nxpwifi_radar_params));
+	radar_params.chandef = chandef;
+	radar_params.cac_time_ms = 0;
+
+	return nxpwifi_send_cmd(priv, HOST_CMD_CHAN_REPORT_REQUEST,
+				HOST_ACT_GEN_SET, 0, &radar_params, true);
+}
+
+/* Abort ongoing CAC when stopping AP operations or during unload */
+void nxpwifi_abort_cac(struct nxpwifi_private *priv)
+{
+	if (priv->wdev.links[0].cac_started) {
+		if (nxpwifi_stop_radar_detection(priv, &priv->dfs_chandef))
+			nxpwifi_dbg(priv->adapter, ERROR,
+				    "failed to stop CAC in FW\n");
+		nxpwifi_dbg(priv->adapter, MSG,
+			    "Aborting delayed work for CAC.\n");
+		wiphy_delayed_work_cancel(priv->adapter->wiphy, &priv->dfs_cac_work);
+		cfg80211_cac_event(priv->netdev, &priv->dfs_chandef,
+				   NL80211_RADAR_CAC_ABORTED, GFP_KERNEL, 0);
+	}
+}
+
+/*
+ * handles channel report event from FW during CAC period. If radar is detected
+ * during CAC, driver indicates the same to cfg80211 and also cancels ongoing
+ * delayed work
+ */
+int nxpwifi_11h_handle_chanrpt_ready(struct nxpwifi_private *priv,
+				     struct sk_buff *skb)
+{
+	struct host_cmd_ds_chan_rpt_event *rpt_event;
+	struct nxpwifi_ie_types_chan_rpt_data *rpt;
+	u16 event_len, tlv_len;
+
+	rpt_event = (void *)(skb->data + sizeof(u32));
+	event_len = skb->len - (sizeof(struct host_cmd_ds_chan_rpt_event) +
+				sizeof(u32));
+
+	if (le32_to_cpu(rpt_event->result) != HOST_RESULT_OK) {
+		nxpwifi_dbg(priv->adapter, ERROR,
+			    "Error in channel report event\n");
+		return -EINVAL;
+	}
+
+	while (event_len >= sizeof(struct nxpwifi_ie_types_header)) {
+		rpt = (void *)&rpt_event->tlvbuf;
+		tlv_len = le16_to_cpu(rpt->header.len);
+
+		switch (le16_to_cpu(rpt->header.type)) {
+		case TLV_TYPE_CHANRPT_11H_BASIC:
+			if (rpt->meas_rpt_map & MEAS_RPT_MAP_RADAR_MASK) {
+				nxpwifi_dbg(priv->adapter, MSG,
+					    "RADAR Detected on channel %d!\n",
+					    priv->dfs_chandef.chan->hw_value);
+
+				wiphy_delayed_work_cancel(priv->adapter->wiphy,
+							  &priv->dfs_cac_work);
+				cfg80211_cac_event(priv->netdev,
+						   &priv->dfs_chandef,
+						   NL80211_RADAR_CAC_ABORTED,
+						   GFP_KERNEL, 0);
+				cfg80211_radar_event(priv->adapter->wiphy,
+						     &priv->dfs_chandef,
+						     GFP_KERNEL);
+			}
+			break;
+		default:
+			break;
+		}
+
+		event_len -= (tlv_len + sizeof(rpt->header));
+	}
+
+	return 0;
+}
+
+/* Handler for radar detected event from FW */
+int nxpwifi_11h_handle_radar_detected(struct nxpwifi_private *priv,
+				      struct sk_buff *skb)
+{
+	struct nxpwifi_radar_det_event *rdr_event;
+
+	rdr_event = (void *)(skb->data + sizeof(u32));
+
+	nxpwifi_dbg(priv->adapter, MSG,
+		    "radar detected; indicating kernel\n");
+	if (priv->wdev.links[0].cac_started) {
+		if (nxpwifi_stop_radar_detection(priv, &priv->dfs_chandef))
+			nxpwifi_dbg(priv->adapter, ERROR,
+				    "Failed to stop CAC in FW\n");
+		wiphy_delayed_work_cancel(priv->adapter->wiphy, &priv->dfs_cac_work);
+		cfg80211_cac_event(priv->netdev, &priv->dfs_chandef,
+				   NL80211_RADAR_CAC_ABORTED, GFP_KERNEL, 0);
+	}
+	cfg80211_radar_event(priv->adapter->wiphy, &priv->dfs_chandef,
+			     GFP_KERNEL);
+	nxpwifi_dbg(priv->adapter, MSG, "regdomain: %d\n",
+		    rdr_event->reg_domain);
+	nxpwifi_dbg(priv->adapter, MSG, "radar detection type: %d\n",
+		    rdr_event->det_type);
+
+	return 0;
+}
+
+/*
+ * work function for channel switch handling. takes care of updating new channel
+ * definitin to bss config structure, restart AP and indicate channel switch
+ * success to cfg80211
+ */
+void nxpwifi_dfs_chan_sw_work(struct wiphy *wiphy, struct wiphy_work *work)
+{
+	struct nxpwifi_uap_bss_param *bss_cfg;
+	struct wiphy_delayed_work *delayed_work =
+		container_of(work, struct wiphy_delayed_work, work);
+	struct nxpwifi_private *priv = container_of(delayed_work,
+						    struct nxpwifi_private,
+						    dfs_chan_sw_work);
+	struct nxpwifi_adapter *adapter = priv->adapter;
+
+	if (nxpwifi_del_mgmt_ies(priv))
+		nxpwifi_dbg(priv->adapter, ERROR,
+			    "Failed to delete mgmt IEs!\n");
+
+	bss_cfg = &priv->bss_cfg;
+	if (!bss_cfg->beacon_period) {
+		nxpwifi_dbg(adapter, ERROR,
+			    "channel switch: AP already stopped\n");
+		return;
+	}
+
+	if (nxpwifi_send_cmd(priv, HOST_CMD_UAP_BSS_STOP,
+			     HOST_ACT_GEN_SET, 0, NULL, true)) {
+		nxpwifi_dbg(adapter, ERROR,
+			    "channel switch: Failed to stop the BSS\n");
+		return;
+	}
+
+	if (nxpwifi_cfg80211_change_beacon(adapter->wiphy, priv->netdev,
+					   &priv->ap_update_info)) {
+		nxpwifi_dbg(adapter, ERROR,
+			    "channel switch: Failed to set beacon\n");
+		return;
+	}
+
+	nxpwifi_uap_set_channel(priv, bss_cfg, priv->dfs_chandef);
+
+	if (nxpwifi_config_start_uap(priv, bss_cfg)) {
+		nxpwifi_dbg(adapter, ERROR,
+			    "Failed to start AP after channel switch\n");
+		return;
+	}
+
+	nxpwifi_dbg(adapter, MSG,
+		    "indicating channel switch completion to kernel\n");
+
+	cfg80211_ch_switch_notify(priv->netdev, &priv->dfs_chandef, 0);
+
+	if (priv->uap_stop_tx) {
+		netif_carrier_on(priv->netdev);
+		nxpwifi_wake_up_net_dev_queue(priv->netdev, adapter);
+		priv->uap_stop_tx = false;
+	}
+}
-- 
2.34.1