wifi: rtw89: 8851b: add to read efuse version to recognize hardware version B

8851B hardware version A and B use different firmware, but register version
code of these two are the same, so add this helper to read efuse version to
determine which version is installed.
Signed-off-by: Ping-Ke Shih <pkshih@realtek.com>
Signed-off-by: Kalle Valo <kvalo@kernel.org>
Link: https://lore.kernel.org/r/20230512061220.16544-2-pkshih@realtek.com

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

@@ -7,6 +7,10 @@
 #include "mac.h"
 #include "reg.h"
 
+#define EF_FV_OFSET 0x5ea
+#define EF_CV_MASK GENMASK(7, 4)
+#define EF_CV_INV 15
+
 enum rtw89_efuse_bank {
 	RTW89_EFUSE_BANK_WIFI,
 	RTW89_EFUSE_BANK_BT,
@@ -328,3 +332,20 @@ int rtw89_parse_phycap_map(struct rtw89_dev *rtwdev)
 
 	return ret;
 }
+
+int rtw89_read_efuse_ver(struct rtw89_dev *rtwdev, u8 *ecv)
+{
+	int ret;
+	u8 val;
+
+	ret = rtw89_dump_physical_efuse_map(rtwdev, &val, EF_FV_OFSET, 1, false);
+	if (ret)
+		return ret;
+
+	*ecv = u8_get_bits(val, EF_CV_MASK);
+	if (*ecv == EF_CV_INV)
+		return -ENOENT;
+
+	return 0;
+}
+EXPORT_SYMBOL(rtw89_read_efuse_ver);

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

@@ -9,5 +9,6 @@
 
 int rtw89_parse_efuse_map(struct rtw89_dev *rtwdev);
 int rtw89_parse_phycap_map(struct rtw89_dev *rtwdev);
+int rtw89_read_efuse_ver(struct rtw89_dev *rtwdev, u8 *efv);
 
 #endif