wifi: rtw89: regd: extend policy of UNII-4 for IC regulatory

Originally, we have an ACPI function to determine whether to enable UNII-4.
Since IC (Industry Canada) has allowed UNII-4, the ACPI result is extended
to be two bits as below.
  * BIT(0): determine if rtw89_regd::FCC enable UNII-4
  * BIT(1): determine if rtw89_regd::IC enable UNII-4

Besides, to take old platforms into account, we enable UNII-4 on IC if and
only if BIOS configuration enable it.
Signed-off-by: Zong-Zhe Yang <kevin_yang@realtek.com>
Signed-off-by: Ping-Ke Shih <pkshih@realtek.com>
Link: https://msgid.link/20240412115729.8316-7-pkshih@realtek.com

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

@@ -12,7 +12,12 @@ enum rtw89_acpi_dsm_func {
 	RTW89_ACPI_DSM_FUNC_6G_DIS = 3,
 	RTW89_ACPI_DSM_FUNC_6G_BP = 4,
 	RTW89_ACPI_DSM_FUNC_TAS_EN = 5,
-	RTW89_ACPI_DSM_FUNC_59G_EN = 6,
+	RTW89_ACPI_DSM_FUNC_UNII4_SUP = 6,
+};
+
+enum rtw89_acpi_conf_unii4 {
+	RTW89_ACPI_CONF_UNII4_FCC = BIT(0),
+	RTW89_ACPI_CONF_UNII4_IC = BIT(1),
 };
 
 enum rtw89_acpi_policy_mode {

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

@@ -82,6 +82,9 @@ static struct ieee80211_channel rtw89_channels_5ghz[] = {
 	RTW89_DEF_CHAN_5G(5885, 177),
 };
 
+static_assert(RTW89_5GHZ_UNII4_START_INDEX + RTW89_5GHZ_UNII4_CHANNEL_NUM ==
+	      ARRAY_SIZE(rtw89_channels_5ghz));
+
 static struct ieee80211_channel rtw89_channels_6ghz[] = {
 	RTW89_DEF_CHAN_6G(5955, 1),
 	RTW89_DEF_CHAN_6G(5975, 5),

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

@@ -4752,10 +4752,13 @@ struct rtw89_regd {
 };
 
 #define RTW89_REGD_MAX_COUNTRY_NUM U8_MAX
+#define RTW89_5GHZ_UNII4_CHANNEL_NUM 3
+#define RTW89_5GHZ_UNII4_START_INDEX 25
 
 struct rtw89_regulatory_info {
 	const struct rtw89_regd *regd;
 	enum rtw89_reg_6ghz_power reg_6ghz_power;
+	DECLARE_BITMAP(block_unii4, RTW89_REGD_MAX_COUNTRY_NUM);
 	DECLARE_BITMAP(block_6ghz, RTW89_REGD_MAX_COUNTRY_NUM);
 };
 

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

@@ -341,51 +341,60 @@ do { \
 static void rtw89_regd_setup_unii4(struct rtw89_dev *rtwdev,
 				   struct wiphy *wiphy)
 {
+	struct rtw89_regulatory_info *regulatory = &rtwdev->regulatory;
 	const struct rtw89_chip_info *chip = rtwdev->chip;
-	bool regd_allow_unii_4 = chip->support_unii4;
 	struct ieee80211_supported_band *sband;
 	struct rtw89_acpi_dsm_result res = {};
+	bool enable_by_fcc;
+	bool enable_by_ic;
 	int ret;
 	u8 val;
+	int i;
 
-	if (!chip->support_unii4)
-		goto bottom;
+	sband = wiphy->bands[NL80211_BAND_5GHZ];
+	if (!sband)
+		return;
 
-	ret = rtw89_acpi_evaluate_dsm(rtwdev, RTW89_ACPI_DSM_FUNC_59G_EN, &res);
+	if (!chip->support_unii4) {
+		sband->n_channels -= RTW89_5GHZ_UNII4_CHANNEL_NUM;
+		return;
+	}
+
+	bitmap_fill(regulatory->block_unii4, RTW89_REGD_MAX_COUNTRY_NUM);
+
+	ret = rtw89_acpi_evaluate_dsm(rtwdev, RTW89_ACPI_DSM_FUNC_UNII4_SUP, &res);
 	if (ret) {
 		rtw89_debug(rtwdev, RTW89_DBG_REGD,
 			    "acpi: cannot eval unii 4: %d\n", ret);
+		enable_by_fcc = true;
+		enable_by_ic = false;
 		goto bottom;
 	}
 
 	val = res.u.value;
+	enable_by_fcc = u8_get_bits(val, RTW89_ACPI_CONF_UNII4_FCC);
+	enable_by_ic = u8_get_bits(val, RTW89_ACPI_CONF_UNII4_IC);
 
 	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;
-	}
+		    "acpi: eval if allow unii-4: 0x%x\n", val);
 
 bottom:
-	rtw89_debug(rtwdev, RTW89_DBG_REGD, "regd: allow unii 4: %d\n",
-		    regd_allow_unii_4);
-
-	if (regd_allow_unii_4)
-		return;
-
-	sband = wiphy->bands[NL80211_BAND_5GHZ];
-	if (!sband)
-		return;
+	for (i = 0; i < ARRAY_SIZE(rtw89_regd_map); i++) {
+		const struct rtw89_regd *regd = &rtw89_regd_map[i];
 
-	sband->n_channels -= 3;
+		switch (regd->txpwr_regd[RTW89_BAND_5G]) {
+		case RTW89_FCC:
+			if (enable_by_fcc)
+				clear_bit(i, regulatory->block_unii4);
+			break;
+		case RTW89_IC:
+			if (enable_by_ic)
+				clear_bit(i, regulatory->block_unii4);
+			break;
+		default:
+			break;
+		}
+	}
 }
 
 static void __rtw89_regd_setup_policy_6ghz(struct rtw89_dev *rtwdev, bool block,
@@ -562,6 +571,35 @@ int rtw89_regd_init(struct rtw89_dev *rtwdev,
 	return 0;
 }
 
+static void rtw89_regd_apply_policy_unii4(struct rtw89_dev *rtwdev,
+					  struct wiphy *wiphy)
+{
+	struct rtw89_regulatory_info *regulatory = &rtwdev->regulatory;
+	const struct rtw89_chip_info *chip = rtwdev->chip;
+	const struct rtw89_regd *regd = regulatory->regd;
+	struct ieee80211_supported_band *sband;
+	u8 index;
+	int i;
+
+	sband = wiphy->bands[NL80211_BAND_5GHZ];
+	if (!sband)
+		return;
+
+	if (!chip->support_unii4)
+		return;
+
+	index = rtw89_regd_get_index(regd);
+	if (index != RTW89_REGD_MAX_COUNTRY_NUM &&
+	    !test_bit(index, regulatory->block_unii4))
+		return;
+
+	rtw89_debug(rtwdev, RTW89_DBG_REGD, "%c%c unii-4 is blocked by policy\n",
+		    regd->alpha2[0], regd->alpha2[1]);
+
+	for (i = RTW89_5GHZ_UNII4_START_INDEX; i < sband->n_channels; i++)
+		sband->channels[i].flags |= IEEE80211_CHAN_DISABLED;
+}
+
 static void rtw89_regd_apply_policy_6ghz(struct rtw89_dev *rtwdev,
 					 struct wiphy *wiphy)
 {
@@ -602,6 +640,7 @@ static void rtw89_regd_notifier_apply(struct rtw89_dev *rtwdev,
 	else
 		wiphy->regulatory_flags &= ~REGULATORY_COUNTRY_IE_IGNORE;
 
+	rtw89_regd_apply_policy_unii4(rtwdev, wiphy);
 	rtw89_regd_apply_policy_6ghz(rtwdev, wiphy);
 }