wifi: ath12k: handle WMI event for real noise floor calculation

At present, the ATH12K_DEFAULT_NOISE_FLOOR (-95) is used to calculate RSSI
value, providing an estimated noise floor value. Consequently, the RSSI
value is also approximate. This works but however, using actual noise floor
value will enable the reporting of the true RSSI value.

The firmware possesses the necessary data to determine the actual noise
floor. This data is provided to the host via the WMI event
WMI_PDEV_RSSI_DBM_CONVERSION_PARAMS_INFO_EVENTID, which includes the
runtime parameters needed for calculating the real noise floor in dBm. This
event is triggered by the firmware during channel changes, temperature
offset adjustments, and hardware chainmask modifications. The individual
TLVs may not always be present in each event. For instance, temperature
information might only appear if there is a change in offset due to
temperature variation.

Add support to handle and parse this WMI event. Use the received values to
calculate and store the noise floor value.

A subsequent change will use this noise floor value in the actual RSSI
calculation.

Tested-on: QCN9274 hw2.0 PCI WLAN.WBE.1.4.1-00199-QCAHKSWPL_SILICONZ-1

Signed-off-by: Raj Kumar Bhagat <quic_rajkbhag@quicinc.com>
Co-developed-by: Aditya Kumar Singh <aditya.kumar.singh@oss.qualcomm.com>
Signed-off-by: Aditya Kumar Singh <aditya.kumar.singh@oss.qualcomm.com>
Reviewed-by: Vasanthakumar Thiagarajan <vasanthakumar.thiagarajan@oss.qualcomm.com>
Link: https://patch.msgid.link/20250623-support_real_noise_floor-v2-1-974bbafa317e@oss.qualcomm.com
Signed-off-by: Jeff Johnson <jeff.johnson@oss.qualcomm.com>

1 files changed, 226 insertions, 0 deletions

diff --git a/drivers/net/wireless/ath/ath12k/wmi.c b/drivers/net/wireless/ath/ath12k/wmi.c
index b38f22118d73..3ec58feab755 100644
--- a/drivers/net/wireless/ath/ath12k/wmi.c
+++ b/drivers/net/wireless/ath/ath12k/wmi.c
@@ -9319,6 +9319,229 @@ static void ath12k_wmi_process_tpc_stats(struct ath12k_base *ab,
 }
 #endif
 
+static int
+ath12k_wmi_rssi_dbm_conv_info_evt_subtlv_parser(struct ath12k_base *ab,
+						u16 tag, u16 len,
+						const void *ptr, void *data)
+{
+	const struct ath12k_wmi_rssi_dbm_conv_temp_info_params *temp_info;
+	const struct ath12k_wmi_rssi_dbm_conv_info_params *param_info;
+	struct ath12k_wmi_rssi_dbm_conv_info_arg *rssi_info = data;
+	struct ath12k_wmi_rssi_dbm_conv_param_arg param_arg;
+	s32 nf_hw_dbm[ATH12K_MAX_NUM_NF_HW_DBM];
+	u8 num_20mhz_segments;
+	s8 min_nf, *nf_ptr;
+	int i, j;
+
+	switch (tag) {
+	case WMI_TAG_RSSI_DBM_CONVERSION_PARAMS_INFO:
+		if (len < sizeof(*param_info)) {
+			ath12k_warn(ab,
+				    "RSSI dbm conv subtlv 0x%x invalid len %d rcvd",
+				    tag, len);
+			return -EINVAL;
+		}
+
+		param_info = ptr;
+
+		param_arg.curr_bw = le32_to_cpu(param_info->curr_bw);
+		param_arg.curr_rx_chainmask = le32_to_cpu(param_info->curr_rx_chainmask);
+
+		/* The received array is actually a 2D byte-array for per chain,
+		 * per 20MHz subband. Convert to 2D byte-array
+		 */
+		nf_ptr = &param_arg.nf_hw_dbm[0][0];
+
+		for (i = 0; i < ATH12K_MAX_NUM_NF_HW_DBM; i++) {
+			nf_hw_dbm[i] = a_sle32_to_cpu(param_info->nf_hw_dbm[i]);
+
+			for (j = 0; j < 4; j++) {
+				*nf_ptr = (nf_hw_dbm[i] >> (j * 8)) & 0xFF;
+				nf_ptr++;
+			}
+		}
+
+		switch (param_arg.curr_bw) {
+		case WMI_CHAN_WIDTH_20:
+			num_20mhz_segments = 1;
+			break;
+		case WMI_CHAN_WIDTH_40:
+			num_20mhz_segments = 2;
+			break;
+		case WMI_CHAN_WIDTH_80:
+			num_20mhz_segments = 4;
+			break;
+		case WMI_CHAN_WIDTH_160:
+			num_20mhz_segments = 8;
+			break;
+		case WMI_CHAN_WIDTH_320:
+			num_20mhz_segments = 16;
+			break;
+		default:
+			ath12k_warn(ab, "Invalid current bandwidth %d in RSSI dbm event",
+				    param_arg.curr_bw);
+			/* In error case, still consider the primary 20 MHz segment since
+			 * that would be much better than instead of dropping the whole
+			 * event
+			 */
+			num_20mhz_segments = 1;
+		}
+
+		min_nf = ATH12K_DEFAULT_NOISE_FLOOR;
+
+		for (i = 0; i < ATH12K_MAX_NUM_ANTENNA; i++) {
+			if (!(param_arg.curr_rx_chainmask & BIT(i)))
+				continue;
+
+			for (j = 0; j < num_20mhz_segments; j++) {
+				if (param_arg.nf_hw_dbm[i][j] < min_nf)
+					min_nf = param_arg.nf_hw_dbm[i][j];
+			}
+		}
+
+		rssi_info->min_nf_dbm = min_nf;
+		rssi_info->nf_dbm_present = true;
+		break;
+	case WMI_TAG_RSSI_DBM_CONVERSION_TEMP_OFFSET_INFO:
+		if (len < sizeof(*temp_info)) {
+			ath12k_warn(ab,
+				    "RSSI dbm conv subtlv 0x%x invalid len %d rcvd",
+				    tag, len);
+			return -EINVAL;
+		}
+
+		temp_info = ptr;
+		rssi_info->temp_offset = a_sle32_to_cpu(temp_info->offset);
+		rssi_info->temp_offset_present = true;
+		break;
+	default:
+		ath12k_dbg(ab, ATH12K_DBG_WMI,
+			   "Unknown subtlv 0x%x in RSSI dbm conversion event\n", tag);
+	}
+
+	return 0;
+}
+
+static int
+ath12k_wmi_rssi_dbm_conv_info_event_parser(struct ath12k_base *ab,
+					   u16 tag, u16 len,
+					   const void *ptr, void *data)
+{
+	int ret = 0;
+
+	switch (tag) {
+	case WMI_TAG_RSSI_DBM_CONVERSION_PARAMS_INFO_FIXED_PARAM:
+		/* Fixed param is already processed*/
+		break;
+	case WMI_TAG_ARRAY_STRUCT:
+		/* len 0 is expected for array of struct when there
+		 * is no content of that type inside that tlv
+		 */
+		if (len == 0)
+			return 0;
+
+		ret = ath12k_wmi_tlv_iter(ab, ptr, len,
+					  ath12k_wmi_rssi_dbm_conv_info_evt_subtlv_parser,
+					  data);
+		break;
+	default:
+		ath12k_dbg(ab, ATH12K_DBG_WMI,
+			   "Received invalid tag 0x%x for RSSI dbm conv info event\n",
+			   tag);
+		break;
+	}
+
+	return ret;
+}
+
+static int
+ath12k_wmi_rssi_dbm_conv_info_process_fixed_param(struct ath12k_base *ab, u8 *ptr,
+						  size_t len, int *pdev_id)
+{
+	struct ath12k_wmi_rssi_dbm_conv_info_fixed_params *fixed_param;
+	const struct wmi_tlv *tlv;
+	u16 tlv_tag;
+
+	if (len < (sizeof(*fixed_param) + TLV_HDR_SIZE)) {
+		ath12k_warn(ab, "invalid RSSI dbm conv event size %zu\n", len);
+		return -EINVAL;
+	}
+
+	tlv = (struct wmi_tlv *)ptr;
+	tlv_tag = le32_get_bits(tlv->header, WMI_TLV_TAG);
+	ptr += sizeof(*tlv);
+
+	if (tlv_tag != WMI_TAG_RSSI_DBM_CONVERSION_PARAMS_INFO_FIXED_PARAM) {
+		ath12k_warn(ab, "RSSI dbm conv event received without fixed param tlv\n");
+		return -EINVAL;
+	}
+
+	fixed_param = (struct ath12k_wmi_rssi_dbm_conv_info_fixed_params *)ptr;
+	*pdev_id = le32_to_cpu(fixed_param->pdev_id);
+
+	return 0;
+}
+
+static void
+ath12k_wmi_update_rssi_offsets(struct ath12k *ar,
+			       struct ath12k_wmi_rssi_dbm_conv_info_arg *rssi_info)
+{
+	struct ath12k_pdev_rssi_offsets *info = &ar->rssi_info;
+
+	lockdep_assert_held(&ar->data_lock);
+
+	if (rssi_info->temp_offset_present)
+		info->temp_offset = rssi_info->temp_offset;
+
+	if (rssi_info->nf_dbm_present)
+		info->min_nf_dbm = rssi_info->min_nf_dbm;
+
+	info->noise_floor = info->min_nf_dbm + info->temp_offset;
+}
+
+static void
+ath12k_wmi_rssi_dbm_conversion_params_info_event(struct ath12k_base *ab,
+						 struct sk_buff *skb)
+{
+	struct ath12k_wmi_rssi_dbm_conv_info_arg rssi_info;
+	struct ath12k *ar;
+	s32 noise_floor;
+	u32 pdev_id;
+	int ret;
+
+	ret = ath12k_wmi_rssi_dbm_conv_info_process_fixed_param(ab, skb->data, skb->len,
+								&pdev_id);
+	if (ret) {
+		ath12k_warn(ab, "failed to parse fixed param in RSSI dbm conv event: %d\n",
+			    ret);
+		return;
+	}
+
+	rcu_read_lock();
+	ar = ath12k_mac_get_ar_by_pdev_id(ab, pdev_id);
+	/* If pdev is not active, ignore the event */
+	if (!ar)
+		goto out_unlock;
+
+	ret = ath12k_wmi_tlv_iter(ab, skb->data, skb->len,
+				  ath12k_wmi_rssi_dbm_conv_info_event_parser,
+				  &rssi_info);
+	if (ret) {
+		ath12k_warn(ab, "unable to parse RSSI dbm conversion event\n");
+		goto out_unlock;
+	}
+
+	spin_lock_bh(&ar->data_lock);
+	ath12k_wmi_update_rssi_offsets(ar, &rssi_info);
+	noise_floor = ath12k_pdev_get_noise_floor(ar);
+	spin_unlock_bh(&ar->data_lock);
+
+	ath12k_dbg(ab, ATH12K_DBG_WMI,
+		   "RSSI noise floor updated, new value is %d dbm\n", noise_floor);
+out_unlock:
+	rcu_read_unlock();
+}
+
 static void ath12k_wmi_op_rx(struct ath12k_base *ab, struct sk_buff *skb)
 {
 	struct wmi_cmd_hdr *cmd_hdr;
@@ -9450,6 +9673,9 @@ static void ath12k_wmi_op_rx(struct ath12k_base *ab, struct sk_buff *skb)
 	case WMI_11D_NEW_COUNTRY_EVENTID:
 		ath12k_reg_11d_new_cc_event(ab, skb);
 		break;
+	case WMI_PDEV_RSSI_DBM_CONVERSION_PARAMS_INFO_EVENTID:
+		ath12k_wmi_rssi_dbm_conversion_params_info_event(ab, skb);
+		break;
 	/* add Unsupported events (rare) here */
 	case WMI_TBTTOFFSET_EXT_UPDATE_EVENTID:
 	case WMI_PEER_OPER_MODE_CHANGE_EVENTID: