[PATCH v2 2/3] wifi: mt76: connac: factor out rate power limit calculation

[Sean Wang <sean.wang@kernel.org>]

From: Sean Wang <sean.wang@mediatek.com>

Factor out the per-channel rate power limit calculation into a shared
helper.

This avoids duplicating the same regulatory, SAR and rate-limit logic in
multiple paths.

Reported-by: Devin Wittmayer <lucid_duck@justthetip.ca>
Closes: https://lore.kernel.org/linux-wireless/20260130215839.53270-1-lucid_duck@justthetip.ca/
Tested-by: Devin Wittmayer <lucid_duck@justthetip.ca>
Tested-by: Satadru Pramanik <satadru@gmail.com>
Co-developed-by: Devin Wittmayer <lucid_duck@justthetip.ca>
Signed-off-by: Devin Wittmayer <lucid_duck@justthetip.ca>
Signed-off-by: Sean Wang <sean.wang@mediatek.com>
---
v2:
- Rebased onto the latest mt76 tree
- Added Reported-by, Tested-by, Co-developed-by and Signed-off-by tags
---
 .../net/wireless/mediatek/mt76/mt76_connac.h  |  3 ++
 .../wireless/mediatek/mt76/mt76_connac_mcu.c  | 28 +++++++++++++------
 2 files changed, 23 insertions(+), 8 deletions(-)

diff --git a/drivers/net/wireless/mediatek/mt76/mt76_connac.h b/drivers/net/wireless/mediatek/mt76/mt76_connac.h
index d0953e02810b..1549a97873ee 100644
--- a/drivers/net/wireless/mediatek/mt76/mt76_connac.h
+++ b/drivers/net/wireless/mediatek/mt76/mt76_connac.h
@@ -421,6 +421,9 @@ void mt76_connac_gen_ppe_thresh(u8 *he_ppet, int nss, enum nl80211_band band);
 int mt76_connac_init_tx_queues(struct mt76_phy *phy, int idx, int n_desc,
 			       int ring_base, void *wed, u32 flags);
 void mt76_connac_set_txpower_cur(struct mt76_phy *phy, s8 max_power);
+s8 mt76_connac_get_rate_power_limit(struct mt76_phy *phy,
+				    struct ieee80211_channel *chan,
+				    struct mt76_power_limits *limits);
 void mt76_connac_write_hw_txp(struct mt76_dev *dev,
 			      struct mt76_tx_info *tx_info,
 			      void *txp_ptr, u32 id);
diff --git a/drivers/net/wireless/mediatek/mt76/mt76_connac_mcu.c b/drivers/net/wireless/mediatek/mt76/mt76_connac_mcu.c
index 897b065a2be6..1117a22c70ac 100644
--- a/drivers/net/wireless/mediatek/mt76/mt76_connac_mcu.c
+++ b/drivers/net/wireless/mediatek/mt76/mt76_connac_mcu.c
@@ -2223,15 +2223,10 @@ mt76_connac_mcu_rate_txpower_band(struct mt76_phy *phy,
 				.hw_value = ch_list[idx],
 				.band = band,
 			};
-			s8 reg_power, sar_power, max_power;
-
-			reg_power = mt76_connac_get_ch_power(phy, &chan,
-							     tx_power);
-			sar_power = mt76_get_sar_power(phy, &chan, reg_power);
-
-			max_power = mt76_get_rate_power_limits(phy, &chan, limits,
-							       sar_power);
+			s8 max_power;
 
+			max_power = mt76_connac_get_rate_power_limit(phy, &chan,
+								     limits);
 			if (phy->chandef.chan &&
 			    phy->chandef.chan->hw_value == ch_list[idx] &&
 			    phy->chandef.chan->band == band)
@@ -2967,6 +2962,23 @@ int mt76_connac_mcu_rdd_cmd(struct mt76_dev *dev, int cmd, u8 index,
 }
 EXPORT_SYMBOL_GPL(mt76_connac_mcu_rdd_cmd);
 
+s8 mt76_connac_get_rate_power_limit(struct mt76_phy *phy,
+				    struct ieee80211_channel *chan,
+				    struct mt76_power_limits *limits)
+{
+	s8 reg_power, sar_power;
+	int tx_power;
+
+	tx_power = 2 * phy->hw->conf.power_level;
+	if (!tx_power)
+		tx_power = 127;
+
+	reg_power = mt76_connac_get_ch_power(phy, chan, tx_power);
+	sar_power = mt76_get_sar_power(phy, chan, reg_power);
+	return mt76_get_rate_power_limits(phy, chan, limits, sar_power);
+}
+EXPORT_SYMBOL_GPL(mt76_connac_get_rate_power_limit);
+
 static int
 mt76_connac_mcu_send_ram_firmware(struct mt76_dev *dev,
 				  const struct mt76_connac2_fw_trailer *hdr,
-- 
2.43.0