NanoPi R4S has a EEPROM attached to the 2nd I2C bus (U92), which
stores the MAC address.

Changes in v2:
- Added the size of EEPROM
- Added `mac-address` cell to pass the MAC address to kernel
- Removed `read-only` property in EEPROM node

Signed-off-by: Tianling Shen <redacted>
---
 .../boot/dts/rockchip/rk3399-nanopi-r4s.dts    | 18 ++++++++++++++++++
 1 file changed, 18 insertions(+)

diff --git a/arch/arm64/boot/dts/rockchip/rk3399-nanopi-r4s.dts b/arch/arm64/boot/dts/rockchip/rk3399-nanopi-r4s.dts
index cef4d18b599d..50d3b11eb925 100644
--- a/arch/arm64/boot/dts/rockchip/rk3399-nanopi-r4s.dts
+++ b/arch/arm64/boot/dts/rockchip/rk3399-nanopi-r4s.dts

@@ -68,6 +68,24 @@
 	status = "disabled";
 };
 
+&gmac {
+	nvmem-cells = <&mac_address>;
+	nvmem-cells-names = "mac-address";
+};
+
+&i2c2 {
+	eeprom@51 {
+		compatible = "microchip,24c02", "atmel,24c02";
+		reg = <0x51>;
+		pagesize = <16>;
+		size = <256>;
+
+		mac_address: mac-address@fa {
+			reg = <0xfa 0x06>;
+		};
+	};
+};
+
 &i2c4 {
 	status = "disabled";
 };

-- 
2.17.1