rtw88: 8822c: modify rf protection setting

According to some experiments, the original RF register protection
setting of 8822c cannot perfectly make sure that there is no hardware
PI write (direct) during direct write. Modify the setting so that the
hardware block of PI would be turned off via rtw8822c_rstb_3wire()
during the direct write, to avoid RF register racing.

Note that 8822b uses SIPI write (indirect), so 8822b does not
have such problem.
Signed-off-by: Chien-Hsun Liao <ben.liao@realtek.com>
Signed-off-by: Yan-Hsuan Chuang <yhchuang@realtek.com>
Reviewed-by: Chris Chiu <chiu@endlessm.com>
Signed-off-by: Kalle Valo <kvalo@codeaurora.org>

drivers/net/wireless/realtek/rtw88/phy.c

@@ -749,20 +749,10 @@ bool rtw_phy_write_rf_reg(struct rtw_dev *rtwdev, enum rtw_rf_path rf_path,
 	direct_addr = base_addr[rf_path] + (addr << 2);
 	mask &= RFREG_MASK;
 
-	if (addr == RF_CFGCH) {
-		rtw_write32_mask(rtwdev, REG_RSV_CTRL, BITS_RFC_DIRECT, DISABLE_PI);
-		rtw_write32_mask(rtwdev, REG_WLRF1, BITS_RFC_DIRECT, DISABLE_PI);
-	}
-
 	rtw_write32_mask(rtwdev, direct_addr, mask, data);
 
 	udelay(1);
 
-	if (addr == RF_CFGCH) {
-		rtw_write32_mask(rtwdev, REG_RSV_CTRL, BITS_RFC_DIRECT, ENABLE_PI);
-		rtw_write32_mask(rtwdev, REG_WLRF1, BITS_RFC_DIRECT, ENABLE_PI);
-	}
-
 	return true;
 }
 

drivers/net/wireless/realtek/rtw88/rtw8822c.c

@@ -1289,6 +1289,17 @@ static int rtw8822c_mac_init(struct rtw_dev *rtwdev)
 	return 0;
 }
 
+static void rtw8822c_rstb_3wire(struct rtw_dev *rtwdev, bool enable)
+{
+	if (enable) {
+		rtw_write32_mask(rtwdev, REG_RSTB, BIT_RSTB_3WIRE, 0x1);
+		rtw_write32_mask(rtwdev, REG_ANAPAR_A, BIT_ANAPAR_UPDATE, 0x1);
+		rtw_write32_mask(rtwdev, REG_ANAPAR_B, BIT_ANAPAR_UPDATE, 0x1);
+	} else {
+		rtw_write32_mask(rtwdev, REG_RSTB, BIT_RSTB_3WIRE, 0x0);
+	}
+}
+
 static void rtw8822c_set_channel_rf(struct rtw_dev *rtwdev, u8 channel, u8 bw)
 {
 #define RF18_BAND_MASK		(BIT(16) | BIT(9) | BIT(8))
@@ -1337,6 +1348,8 @@ static void rtw8822c_set_channel_rf(struct rtw_dev *rtwdev, u8 channel, u8 bw)
 		break;
 	}
 
+	rtw8822c_rstb_3wire(rtwdev, false);
+
 	rtw_write_rf(rtwdev, RF_PATH_A, RF_LUTWE2, 0x04, 0x01);
 	rtw_write_rf(rtwdev, RF_PATH_A, RF_LUTWA, 0x1f, 0x12);
 	rtw_write_rf(rtwdev, RF_PATH_A, RF_LUTWD0, 0xfffff, rf_rxbb);
@@ -1349,6 +1362,8 @@ static void rtw8822c_set_channel_rf(struct rtw_dev *rtwdev, u8 channel, u8 bw)
 
 	rtw_write_rf(rtwdev, RF_PATH_A, RF_CFGCH, RFREG_MASK, rf_reg18);
 	rtw_write_rf(rtwdev, RF_PATH_B, RF_CFGCH, RFREG_MASK, rf_reg18);
+
+	rtw8822c_rstb_3wire(rtwdev, true);
 }
 
 static void rtw8822c_toggle_igi(struct rtw_dev *rtwdev)

drivers/net/wireless/realtek/rtw88/rtw8822c.h

@@ -190,6 +190,8 @@ const struct rtw_table name ## _tbl = {			\
 #define BIT_3WIRE_TX_EN		BIT(0)
 #define BIT_3WIRE_RX_EN		BIT(1)
 #define BIT_3WIRE_PI_ON		BIT(28)
+#define REG_ANAPAR_A	0x1830
+#define BIT_ANAPAR_UPDATE	BIT(29)
 #define REG_RXAGCCTL0	0x18ac
 #define BITS_RXAGC_CCK		GENMASK(15, 12)
 #define BITS_RXAGC_OFDM		GENMASK(8, 4)
@@ -223,6 +225,8 @@ const struct rtw_table name ## _tbl = {			\
 #define BIT_CCK_BLK_EN		BIT(1)
 #define BIT_CCK_OFDM_BLK_EN	(BIT(0) | BIT(1))
 #define REG_CCAMSK	0x1c80
+#define REG_RSTB	0x1c90
+#define BIT_RSTB_3WIRE		BIT(8)
 #define REG_RX_BREAK	0x1d2c
 #define BIT_COM_RX_GCK_EN	BIT(31)
 #define REG_RXFNCTL	0x1d30
@@ -243,6 +247,7 @@ const struct rtw_table name ## _tbl = {			\
 #define REG_OFDM_TXCNT	0x2de0
 #define REG_ORITXCODE2	0x4100
 #define REG_3WIRE2	0x410c
+#define REG_ANAPAR_B	0x4130
 #define REG_RXAGCCTL	0x41ac
 #define REG_DCKB_I_0	0x41bc
 #define REG_DCKB_I_1	0x41c0