wifi: rtw88: rtw8821c: Implement RTL8821CS (SDIO) efuse parsing

The efuse of the SDIO RTL8821CS chip has only one known member: the mac
address is at offset 0x11a. Add a struct rtw8821cs_efuse describing this
and use it for copying the mac address when the SDIO bus is used.
Signed-off-by: Martin Blumenstingl <martin.blumenstingl@googlemail.com>
Reviewed-by: Ping-Ke Shih <pkshih@realtek.com>
Signed-off-by: Kalle Valo <kvalo@kernel.org>
Link: https://lore.kernel.org/r/20230218152944.48842-4-martin.blumenstingl@googlemail.com

drivers/net/wireless/realtek/rtw88/rtw8821c.c

@@ -32,6 +32,12 @@ static void rtw8821cu_efuse_parsing(struct rtw_efuse *efuse,
 	ether_addr_copy(efuse->addr, map->u.mac_addr);
 }
 
+static void rtw8821cs_efuse_parsing(struct rtw_efuse *efuse,
+				    struct rtw8821c_efuse *map)
+{
+	ether_addr_copy(efuse->addr, map->s.mac_addr);
+}
+
 enum rtw8821ce_rf_set {
 	SWITCH_TO_BTG,
 	SWITCH_TO_WLG,
@@ -77,6 +83,9 @@ static int rtw8821c_read_efuse(struct rtw_dev *rtwdev, u8 *log_map)
 	case RTW_HCI_TYPE_USB:
 		rtw8821cu_efuse_parsing(efuse, map);
 		break;
+	case RTW_HCI_TYPE_SDIO:
+		rtw8821cs_efuse_parsing(efuse, map);
+		break;
 	default:
 		/* unsupported now */
 		return -ENOTSUPP;

drivers/net/wireless/realtek/rtw88/rtw8821c.h

@@ -65,6 +65,11 @@ struct rtw8821ce_efuse {
 	u8 res7;
 };
 
+struct rtw8821cs_efuse {
+	u8 res4[0x4a];			/* 0xd0 */
+	u8 mac_addr[ETH_ALEN];		/* 0x11a */
+} __packed;
+
 struct rtw8821c_efuse {
 	__le16 rtl_id;
 	u8 res0[0x0e];
@@ -94,6 +99,7 @@ struct rtw8821c_efuse {
 	union {
 		struct rtw8821ce_efuse e;
 		struct rtw8821cu_efuse u;
+		struct rtw8821cs_efuse s;
 	};
 };