[PATCH v7 1/2] rtw88: add regulatory process strategy for different chipset

[<yhchuang@realtek.com>]

From: Tzu-En Huang <tehuang@realtek.com>

In Realtek chipset, there are 2 different settings of regulatory,
worldwide chipsets, and chipsets with a specific country.
Since we do not want stack to possibly decrease driver's regulatory,
REGULATORY_STRICT_REG is set, i.e. rtw88 will have the control of its
regulatory. And we ignore regulatory notifications set from user-space,
unless compiled with the compile flag option RTW88_REGD_USER_REG_HINTS.

Regarding chipsets with a specific country, driver calls
regulatory_hint() to tell the stack what regulatory it is. As we do
not want the regulatory of this chipset be changed, driver will not
apply new regulatory notifications from either DRIVER, USER or
COUNTRY_IE.

And for worldwide chipsets, there are many cases we want to describe.
Let's start with case without RTW88_REGD_USER_REG_HINTS. In worldwide
mode, we want to follow the regulatory of an associated AP, but we do
not want to follow the regulatory from other drivers, so we will apply
regulatory notifications from COUNTRY_IE.
For cases with RTW88_REGD_USER_REG_HINTS, if there are not any USER
notifications, driver will also follow the AP's regulatory. On the other
hand, if there are notifications from USER, we want to make sure that the
settings from user-space will not be violated when associating to a new
AP. In this situation, stack will change the regulatory to AP's. And
because we have set REGULATORY_STRICT_REG, stack will intersect driver's
regulatory with AP's. Thus, we provide a custom worldwide regulatory for
intersection, and the result of it will never violate the setting from
USER.

Signed-off-by: Tzu-En Huang <tehuang@realtek.com>
Signed-off-by: Yan-Hsuan Chuang <yhchuang@realtek.com>
---

v3 -> v4
  * squashed with "rtw88: support dynamic user regulatory setting"
  * modify the commit log

v4 -> v5
  * no change

v5 -> v6
  * remove custom world-wide, use stack world-wide
  * surface error codes

v6 -> v7
  * restore custom world-wide
  * modify commit message to be more clear

 drivers/net/wireless/realtek/rtw88/Kconfig | 10 ++++
 drivers/net/wireless/realtek/rtw88/main.c  |  7 ++-
 drivers/net/wireless/realtek/rtw88/main.h  |  1 +
 drivers/net/wireless/realtek/rtw88/regd.c  | 63 ++++++++++++++++++----
 4 files changed, 70 insertions(+), 11 deletions(-)

diff --git a/drivers/net/wireless/realtek/rtw88/Kconfig b/drivers/net/wireless/realtek/rtw88/Kconfig
index 33bd7ed797ff..04b84ec1dfc1 100644
--- a/drivers/net/wireless/realtek/rtw88/Kconfig
+++ b/drivers/net/wireless/realtek/rtw88/Kconfig
@@ -52,4 +52,14 @@ config RTW88_DEBUGFS
 
 	  If unsure, say Y to simplify debug problems
 
+config RTW88_REGD_USER_REG_HINTS
+	bool "Realtek rtw88 user regulatory hints"
+	depends on RTW88_CORE
+	default n
+	help
+	  Enable regulatoy user hints
+
+	  If unsure, say N. This should only be allowed on distributions
+	  that need this to correct the regulatory.
+
 endif
diff --git a/drivers/net/wireless/realtek/rtw88/main.c b/drivers/net/wireless/realtek/rtw88/main.c
index 7640e97706f5..aa23b084adb0 100644
--- a/drivers/net/wireless/realtek/rtw88/main.c
+++ b/drivers/net/wireless/realtek/rtw88/main.c
@@ -1501,8 +1501,11 @@ int rtw_register_hw(struct rtw_dev *rtwdev, struct ieee80211_hw *hw)
 		return ret;
 	}
 
-	if (regulatory_hint(hw->wiphy, rtwdev->regd.alpha2))
-		rtw_err(rtwdev, "regulatory_hint fail\n");
+	if (!rtwdev->efuse.country_worldwide) {
+		ret = regulatory_hint(hw->wiphy, rtwdev->efuse.country_code);
+		if (ret)
+			rtw_warn(rtwdev, "failed to hint regulatory:%d\n", ret);
+	}
 
 	rtw_debugfs_init(rtwdev);
 
diff --git a/drivers/net/wireless/realtek/rtw88/main.h b/drivers/net/wireless/realtek/rtw88/main.h
index c6b590fdb573..35ffc8c6e949 100644
--- a/drivers/net/wireless/realtek/rtw88/main.h
+++ b/drivers/net/wireless/realtek/rtw88/main.h
@@ -1446,6 +1446,7 @@ struct rtw_efuse {
 	u8 addr[ETH_ALEN];
 	u8 channel_plan;
 	u8 country_code[2];
+	bool country_worldwide;
 	u8 rf_board_option;
 	u8 rfe_option;
 	u8 power_track_type;
diff --git a/drivers/net/wireless/realtek/rtw88/regd.c b/drivers/net/wireless/realtek/rtw88/regd.c
index 69744dd65968..27a7fe8395f4 100644
--- a/drivers/net/wireless/realtek/rtw88/regd.c
+++ b/drivers/net/wireless/realtek/rtw88/regd.c
@@ -7,6 +7,18 @@
 #include "debug.h"
 #include "phy.h"
 
+static const struct ieee80211_regdomain rtw88_world_regdom = {
+	.n_reg_rules = 5,
+	.alpha2 =  "99",
+	.reg_rules = {
+		REG_RULE(2412 - 10, 2462 + 10, 40, 0, 20, 0),
+		REG_RULE(2467 - 10, 2484 + 10, 40, 0, 20, NL80211_RRF_NO_IR),
+		REG_RULE(5180 - 10, 5240 + 10, 80, 0, 20, NL80211_RRF_NO_IR),
+		REG_RULE(5260 - 10, 5700 + 10, 80, 0, 20,
+			 NL80211_RRF_NO_IR | NL80211_RRF_DFS),
+		REG_RULE(5745 - 10, 5825 + 10, 80, 0, 20, NL80211_RRF_NO_IR),
+	}
+};
 #define COUNTRY_CHPLAN_ENT(_alpha2, _chplan, _txpwr_regd) \
 	{.alpha2 = (_alpha2), \
 	 .chplan = (_chplan), \
@@ -339,12 +351,31 @@ static struct rtw_regulatory rtw_regd_find_reg_by_name(char *alpha2)
 	return rtw_defined_chplan;
 }
 
+static bool rtw_regd_is_ww(struct rtw_regulatory *reg)
+{
+	if (reg->txpwr_regd == RTW_REGD_WW)
+		return true;
+	return false;
+}
+
 static int rtw_regd_notifier_apply(struct rtw_dev *rtwdev,
 				   struct wiphy *wiphy,
 				   struct regulatory_request *request)
 {
-	if (request->initiator == NL80211_REGDOM_SET_BY_USER)
+	if (request->initiator == NL80211_REGDOM_SET_BY_DRIVER)
+		return -ENOTSUPP;
+	if (request->initiator == NL80211_REGDOM_SET_BY_USER &&
+	    !IS_ENABLED(CONFIG_RTW88_REGD_USER_REG_HINTS))
+		return -EPERM;
+	if (request->initiator == NL80211_REGDOM_SET_BY_COUNTRY_IE &&
+	    !rtw_regd_is_ww(&rtwdev->regd))
+		return -EINVAL;
+	if (request->initiator == NL80211_REGDOM_SET_BY_CORE &&
+	    !rtwdev->efuse.country_worldwide) {
+		rtwdev->regd =
+			rtw_regd_find_reg_by_name(rtwdev->efuse.country_code);
 		return 0;
+	}
 	rtwdev->regd = rtw_regd_find_reg_by_name(request->alpha2);
 	rtw_regd_apply_world_flags(wiphy, request->initiator);
 
@@ -352,15 +383,22 @@ static int rtw_regd_notifier_apply(struct rtw_dev *rtwdev,
 }
 
 static int
-rtw_regd_init_wiphy(struct rtw_regulatory *reg, struct wiphy *wiphy,
+rtw_regd_init_wiphy(struct rtw_dev *rtwdev, struct wiphy *wiphy,
 		    void (*reg_notifier)(struct wiphy *wiphy,
 					 struct regulatory_request *request))
 {
+	struct rtw_regulatory *reg = &rtwdev->regd;
+
 	wiphy->reg_notifier = reg_notifier;
 
-	wiphy->regulatory_flags &= ~REGULATORY_CUSTOM_REG;
-	wiphy->regulatory_flags &= ~REGULATORY_STRICT_REG;
-	wiphy->regulatory_flags &= ~REGULATORY_DISABLE_BEACON_HINTS;
+	if (rtw_regd_is_ww(reg)) {
+		rtwdev->efuse.country_worldwide = true;
+		wiphy->regulatory_flags |= REGULATORY_CUSTOM_REG;
+		wiphy_apply_custom_regulatory(wiphy, &rtw88_world_regdom);
+	} else {
+		rtwdev->efuse.country_worldwide = false;
+	}
+	wiphy->regulatory_flags |= REGULATORY_STRICT_REG;
 
 	rtw_regd_apply_hw_cap_flags(wiphy);
 
@@ -377,7 +415,7 @@ int rtw_regd_init(struct rtw_dev *rtwdev,
 		return -EINVAL;
 
 	rtwdev->regd = rtw_regd_find_reg_by_name(rtwdev->efuse.country_code);
-	rtw_regd_init_wiphy(&rtwdev->regd, wiphy, reg_notifier);
+	rtw_regd_init_wiphy(rtwdev, wiphy, reg_notifier);
 
 	return 0;
 }
@@ -387,12 +425,19 @@ void rtw_regd_notifier(struct wiphy *wiphy, struct regulatory_request *request)
 	struct ieee80211_hw *hw = wiphy_to_ieee80211_hw(wiphy);
 	struct rtw_dev *rtwdev = hw->priv;
 	struct rtw_hal *hal = &rtwdev->hal;
+	int ret;
 
-	rtw_regd_notifier_apply(rtwdev, wiphy, request);
+	ret = rtw_regd_notifier_apply(rtwdev, wiphy, request);
+	if (ret) {
+		rtw_warn(rtwdev, "failed to apply regulatory from initiator %d: %d\n",
+			 request->initiator, ret);
+		return;
+	}
 	rtw_dbg(rtwdev, RTW_DBG_REGD,
 		"get alpha2 %c%c from initiator %d, mapping to chplan 0x%x, txregd %d\n",
-		request->alpha2[0], request->alpha2[1], request->initiator,
-		rtwdev->regd.chplan, rtwdev->regd.txpwr_regd);
+		request->alpha2[0], request->alpha2[1],
+		request->initiator, rtwdev->regd.chplan,
+		rtwdev->regd.txpwr_regd);
 
 	rtw_phy_set_tx_power_level(rtwdev, hal->current_channel);
 }
-- 
2.17.1