wifi: rtw89: regd: judge UNII-4 according to BIOS and chip

For realtek regulatory, there are following two kinds of configurations
to determine whether to allow UNII-4 band, i.e. 5.9GHz channels.

1. default setting according to whether chip support it or not
2. evaluate realtek ACPI DSM with RTW89_ACPI_DSM_FUNC_59G_EN (func. 6)

If (1) is false, we won't try (2) and just disallow UNII-4. Otherwise,
if (2) is not supported or returns a non-specific value, we follow the
default setting either. Besides, this commit aims to add decision logic
in rtw89 regulatory. Actually, driver doesn't register UNII-4 yet. That
will be handled by another commit.
Signed-off-by: Zong-Zhe Yang <kevin_yang@realtek.com>
Signed-off-by: Ping-Ke Shih <pkshih@realtek.com>
Signed-off-by: Kalle Valo <kvalo@kernel.org>
Link: https://lore.kernel.org/r/20230508081211.38760-3-pkshih@realtek.com

drivers/net/wireless/realtek/rtw89/core.c

@@ -3850,7 +3850,12 @@ static int rtw89_core_register_hw(struct rtw89_dev *rtwdev)
 		return ret;
 	}
 
-	hw->wiphy->reg_notifier = rtw89_regd_notifier;
+	ret = rtw89_regd_setup(rtwdev);
+	if (ret) {
+		rtw89_err(rtwdev, "failed to set up regd\n");
+		goto err_free_supported_band;
+	}
+
 	hw->wiphy->sar_capa = &rtw89_sar_capa;
 
 	ret = ieee80211_register_hw(hw);

drivers/net/wireless/realtek/rtw89/core.h

@@ -3179,6 +3179,7 @@ struct rtw89_chip_info {
 	u8 support_chanctx_num;
 	u8 support_bands;
 	bool support_bw160;
+	bool support_unii4;
 	bool support_ul_tb_ctrl;
 	bool hw_sec_hdr;
 	u8 rf_path_num;
@@ -5044,6 +5045,7 @@ int rtw89_core_release_sta_ba_entry(struct rtw89_dev *rtwdev,
 void rtw89_vif_type_mapping(struct ieee80211_vif *vif, bool assoc);
 int rtw89_chip_info_setup(struct rtw89_dev *rtwdev);
 bool rtw89_ra_report_to_bitrate(struct rtw89_dev *rtwdev, u8 rpt_rate, u16 *bitrate);
+int rtw89_regd_setup(struct rtw89_dev *rtwdev);
 int rtw89_regd_init(struct rtw89_dev *rtwdev,
 		    void (*reg_notifier)(struct wiphy *wiphy, struct regulatory_request *request));
 void rtw89_regd_notifier(struct wiphy *wiphy, struct regulatory_request *request);

drivers/net/wireless/realtek/rtw89/regd.c

@@ -2,6 +2,7 @@
 /* Copyright(c) 2019-2020  Realtek Corporation
  */
 
+#include "acpi.h"
 #include "debug.h"
 #include "ps.h"
 
@@ -282,6 +283,56 @@ do { \
 		    __r->txpwr_regd[RTW89_BAND_6G]); \
 } while (0)
 
+static void rtw89_regd_setup_unii4(struct rtw89_dev *rtwdev,
+				   struct wiphy *wiphy)
+{
+	const struct rtw89_chip_info *chip = rtwdev->chip;
+	bool regd_allow_unii_4 = chip->support_unii4;
+	int ret;
+	u8 val;
+
+	if (!chip->support_unii4)
+		goto bottom;
+
+	ret = rtw89_acpi_evaluate_dsm(rtwdev, RTW89_ACPI_DSM_FUNC_59G_EN, &val);
+	if (ret) {
+		rtw89_debug(rtwdev, RTW89_DBG_REGD,
+			    "acpi: cannot eval unii 4: %d\n", ret);
+		goto bottom;
+	}
+
+	rtw89_debug(rtwdev, RTW89_DBG_REGD,
+		    "acpi: eval if allow unii 4: %d\n", val);
+
+	switch (val) {
+	case 0:
+		regd_allow_unii_4 = false;
+		break;
+	case 1:
+		regd_allow_unii_4 = true;
+		break;
+	default:
+		break;
+	}
+
+bottom:
+	rtw89_debug(rtwdev, RTW89_DBG_REGD, "regd: allow unii 4: %d\n",
+		    regd_allow_unii_4);
+}
+
+int rtw89_regd_setup(struct rtw89_dev *rtwdev)
+{
+	struct wiphy *wiphy = rtwdev->hw->wiphy;
+
+	if (!wiphy)
+		return -EINVAL;
+
+	rtw89_regd_setup_unii4(rtwdev, wiphy);
+
+	wiphy->reg_notifier = rtw89_regd_notifier;
+	return 0;
+}
+
 int rtw89_regd_init(struct rtw89_dev *rtwdev,
 		    void (*reg_notifier)(struct wiphy *wiphy,
 					 struct regulatory_request *request))

drivers/net/wireless/realtek/rtw89/rtw8851b.c

@@ -123,6 +123,7 @@ const struct rtw89_chip_info rtw8851b_chip_info = {
 	.support_bands		= BIT(NL80211_BAND_2GHZ) |
 				  BIT(NL80211_BAND_5GHZ),
 	.support_bw160		= false,
+	.support_unii4		= true,
 	.support_ul_tb_ctrl	= true,
 	.hw_sec_hdr		= false,
 	.rf_path_num		= 1,

drivers/net/wireless/realtek/rtw89/rtw8852a.c

@@ -2105,6 +2105,7 @@ const struct rtw89_chip_info rtw8852a_chip_info = {
 	.support_bands		= BIT(NL80211_BAND_2GHZ) |
 				  BIT(NL80211_BAND_5GHZ),
 	.support_bw160		= false,
+	.support_unii4		= false,
 	.support_ul_tb_ctrl     = false,
 	.hw_sec_hdr		= false,
 	.rf_path_num		= 2,

drivers/net/wireless/realtek/rtw89/rtw8852b.c

@@ -2536,6 +2536,7 @@ const struct rtw89_chip_info rtw8852b_chip_info = {
 	.support_bands		= BIT(NL80211_BAND_2GHZ) |
 				  BIT(NL80211_BAND_5GHZ),
 	.support_bw160		= false,
+	.support_unii4		= true,
 	.support_ul_tb_ctrl	= true,
 	.hw_sec_hdr		= false,
 	.rf_path_num		= 2,

drivers/net/wireless/realtek/rtw89/rtw8852c.c

@@ -2836,6 +2836,7 @@ const struct rtw89_chip_info rtw8852c_chip_info = {
 				  BIT(NL80211_BAND_5GHZ) |
 				  BIT(NL80211_BAND_6GHZ),
 	.support_bw160		= true,
+	.support_unii4		= true,
 	.support_ul_tb_ctrl     = false,
 	.hw_sec_hdr		= true,
 	.rf_path_num		= 2,