[PATCH v4] arm64: dts: rockchip: add EEPROM node for NanoPi R4S

[Tianling Shen <cnsztl@gmail.com>]

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

FriendlyElec ship two versions of the R4S [1]: The standard as well
as the enterprise edition with only the enterprise edition including
the EEPROM chip that stores the unique MAC address.

1. https://wiki.friendlyelec.com/wiki/index.php/NanoPi_R4S#Differences_Between_R4S_Standard_Version_.26_R4S_Enterprise_Version

Changes in v4:
- Removed `mac-address` cell as it breaks the standard edition

Changes in v3:
- Added address-cells and size-cells

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 <cnsztl@gmail.com>
---
 arch/arm64/boot/dts/rockchip/rk3399-nanopi-r4s.dts | 11 +++++++++++
 1 file changed, 11 insertions(+)

diff --git a/arch/arm64/boot/dts/rockchip/rk3399-nanopi-r4s.dts b/arch/arm64/boot/dts/rockchip/rk3399-nanopi-r4s.dts
index fe5b52610010..42c99573ab27 100644
--- a/arch/arm64/boot/dts/rockchip/rk3399-nanopi-r4s.dts
+++ b/arch/arm64/boot/dts/rockchip/rk3399-nanopi-r4s.dts
@@ -68,6 +68,17 @@ &emmc_phy {
 	status = "disabled";
 };
 
+&i2c2 {
+	eeprom@51 {
+		compatible = "microchip,24c02", "atmel,24c02";
+		reg = <0x51>;
+		pagesize = <16>;
+		size = <256>;
+		#address-cells = <1>;
+		#size-cells = <1>;
+	};
+};
+
 &i2c4 {
 	status = "disabled";
 };
-- 
2.25.1