[PATCH 1/1] riscv: dts: spacemit: enable onboard eeprom for OrangePi

[Gong Shuai]

On 9/1/2026 4:00 PM, Chukun Pan wrote:
> Enable the i2c2 bus and add the connected GT24C02B EEPROM.
> 
> [   6.766] TlvInfo Header:
> [   6.766]    Id String:    TlvInfo
> [   6.769]    Version:      1
> [   6.772]    Total Length: 38
> [   6.775] TLV Name             Code Len Value
> [   6.779] -------------------- ---- --- -----
> [   6.783] Base MAC Address     0x24   6 .....
> [   6.788] MAC Addresses        0x2A   2 2
> [   6.792] Product Name         0x21  15 x1_orangepi-r2s
> [   6.797] Unknown              0x41   1  0x01
> [   6.801] CRC-32               0xFE   4 0xE5A74B18
> [   6.806] Checksum is valid.
> 
> Signed-off-by: Chukun Pan <amadeus at jmu.edu.cn>
> ---
> This patch depends on the following to avoid conflicts:
> https://lore.kernel.org/lkml/20260802100101.327815-1-amadeus@jmu.edu.cn/
> ---
>   .../boot/dts/spacemit/k1-orangepi-r2s.dts     | 30 ++++++++++++++++++
>   .../boot/dts/spacemit/k1-orangepi-rv2.dts     | 31 +++++++++++++++++++
>   2 files changed, 61 insertions(+)
> 
> diff --git a/arch/riscv/boot/dts/spacemit/k1-orangepi-r2s.dts b/arch/riscv/boot/dts/spacemit/k1-orangepi-r2s.dts
> index 2d1ba34cb00e..7125f2882ce8 100644
> --- a/arch/riscv/boot/dts/spacemit/k1-orangepi-r2s.dts
> +++ b/arch/riscv/boot/dts/spacemit/k1-orangepi-r2s.dts
> @@ -13,6 +13,7 @@ / {
>   	compatible = "xunlong,orangepi-r2s", "spacemit,k1";
>   
>   	aliases {
> +		i2c2 = &i2c2;
>   		i2c8 = &i2c8;
>   		serial0 = &uart0;
>   		ethernet0 = &eth0;
> @@ -112,6 +113,35 @@ rgmii1: phy at 1 {
>   	};
>   };
>   
> +&i2c2 {
> +	pinctrl-names = "default";
> +	pinctrl-0 = <&i2c2_0_cfg>;
> +	status = "okay";
> +
> +	eeprom at 50 {
> +		compatible = "atmel,24c02";
> +		reg = <0x50>;
> +		pagesize = <16>;
> +		size = <256>;
> +		read-only;
> +		vcc-supply = <&buck3_1v8>;
> +
> +		nvmem-layout {
> +			compatible = "onie,tlv-layout";
> +
> +			mac-address {
> +				#nvmem-cell-cells = <1>;
> +			};
> +
> +			num-macs {
> +			};
> +
> +			product-name {
> +			};
> +		};
> +	};
> +};
> +
>   &i2c8 {
>   	pinctrl-names = "default";
>   	pinctrl-0 = <&i2c8_cfg>;
> diff --git a/arch/riscv/boot/dts/spacemit/k1-orangepi-rv2.dts b/arch/riscv/boot/dts/spacemit/k1-orangepi-rv2.dts
> index f7547a4da71a..837616255464 100644
> --- a/arch/riscv/boot/dts/spacemit/k1-orangepi-rv2.dts
> +++ b/arch/riscv/boot/dts/spacemit/k1-orangepi-rv2.dts
> @@ -17,6 +17,8 @@ aliases {
>   		serial0 = &uart0;
>   		ethernet0 = &eth0;
>   		ethernet1 = &eth1;
> +		i2c2 = &i2c2;
> +		i2c8 = &i2c8;
>   		mmc0 = &emmc;
>   		mmc1 = &sdhci0;
>   	};
> @@ -138,6 +140,35 @@ rgmii1: phy at 1 {
>   	};
>   };
>   
> +&i2c2 {
> +	pinctrl-names = "default";
> +	pinctrl-0 = <&i2c2_0_cfg>;
> +	status = "okay";
> +
> +	eeprom at 50 {
> +		compatible = "atmel,24c02";
> +		reg = <0x50>;
> +		pagesize = <16>;
> +		size = <256>;
> +		read-only;
> +		vcc-supply = <&buck3_1v8>;
> +
> +		nvmem-layout {
> +			compatible = "onie,tlv-layout";
> +
> +			mac-address {
> +				#nvmem-cell-cells = <1>;
> +			};
> +
> +			num-macs {
> +			};
> +
> +			product-name {
> +			};
> +		};
> +	};
> +};
> +
>   &i2c8 {
>   	pinctrl-names = "default";
>   	pinctrl-0 = <&i2c8_cfg>;


Hi Chukun,

I have tested this patch on an OrangePi RV2 with a kernel built from
linux-next (next-20260904).

With the patch applied, the i2c2 bus comes up and a 24C02-compatible
EEPROM (256 bytes) is probed at 2-0050. Reading the raw contents via

     hexdump -C /sys/bus/nvmem/devices/2-00500/nvmem

shows a valid ONIE TlvInfo table, and the nvmem cells
(product-name, mac-address, num-macs, crc32) are properly exposed.
The Product Name field reads "x1_orangepi-rv2", which matches this
board.

Tested-by: Gong Shuai <gsh517025 at gmail.com> # OrangePi-RV2


I also tested the MAC address wiring below on top of this patch, with
the nvmem-cells references added to eth0/eth1, eth0 picks up the base
MAC address stored in the EEPROM and eth1 gets the base + 1; both
addresses stay stable across reboots.


diff --git a/arch/riscv/boot/dts/spacemit/k1-orangepi-rv2.dts b/arch/riscv/boot/dts/spacemit/k1-orangepi-rv2.dts
index 837616255464..44b81268c802 100644
--- a/arch/riscv/boot/dts/spacemit/k1-orangepi-rv2.dts
+++ b/arch/riscv/boot/dts/spacemit/k1-orangepi-rv2.dts
@@ -93,6 +93,8 @@ &emmc {
};

&eth0 {
+   nvmem-cells = <&mac_address 0>;
+   nvmem-cell-names = "mac-address";
  phy-handle = <&rgmii0>;
  phy-mode = "rgmii-id";
  pinctrl-names = "default";
@@ -117,6 +119,8 @@ rgmii0: phy at 1 {
};

&eth1 {
+   nvmem-cells = <&mac_address 1>;
+   nvmem-cell-names = "mac-address";
  phy-handle = <&rgmii1>;
  phy-mode = "rgmii-id";
  pinctrl-names = "default";
@@ -156,7 +160,7 @@ eeprom at 50 {
	nvmem-layout {
	   compatible = "onie,tlv-layout";

-         mac-address {
+         mac_address: mac-address {
		  #nvmem-cell-cells = <1>;
	   };


But I am not sure whether this wiring should be part of this patch.
Without such wiring, the kernel falls back to random MAC addresses
on this board.

Best regards,
Shuai