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

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

[Chukun Pan]

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@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@1 {
 	};
 };
 
+&i2c2 {
+	pinctrl-names = "default";
+	pinctrl-0 = <&i2c2_0_cfg>;
+	status = "okay";
+
+	eeprom@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@1 {
 	};
 };
 
+&i2c2 {
+	pinctrl-names = "default";
+	pinctrl-0 = <&i2c2_0_cfg>;
+	status = "okay";
+
+	eeprom@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>;
-- 
2.34.1

Re: [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@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@1 {
>   	};
>   };
>   
> +&i2c2 {
> +	pinctrl-names = "default";
> +	pinctrl-0 = <&i2c2_0_cfg>;
> +	status = "okay";
> +
> +	eeprom@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@1 {
>   	};
>   };
>   
> +&i2c2 {
> +	pinctrl-names = "default";
> +	pinctrl-0 = <&i2c2_0_cfg>;
> +	status = "okay";
> +
> +	eeprom@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@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@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@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

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

[Chukun Pan]

Hi,

> -         mac-address {
> +         mac_address: mac-address {

This requires removing the aliases for Ethernet.

> 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.

Currently, U-Boot patches the MAC address using the Ethernet alias
from the Device Tree. The vendor U-Boot reads the MAC address from
the eeprom. I think the mainline U-Boot will add this feature, so
we don't need to add this one?

Thanks,
Chukun

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

[Yixun Lan]

Hi Chukun,

On 14:30 Mon 07 Sep     , Chukun Pan wrote:
> Hi,
> 
> > -         mac-address {
> > +         mac_address: mac-address {
> 
> This requires removing the aliases for Ethernet.
> 
> > 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.
> 
> Currently, U-Boot patches the MAC address using the Ethernet alias
> from the Device Tree. The vendor U-Boot reads the MAC address from
> the eeprom. I think the mainline U-Boot will add this feature, so
> we don't need to add this one?
> 
I think it would take long time for us to get there - to have a mainline
U-Boot which support parsing MAC address from eeprom. So, I have no
objection to the idea of adding mac info into the dts.. 

Just let me know if you guys want to do in another separate patch, so I could
take this patch first, or want to squash together and send an incremental
 version? P.S checked k1-bananapi-cm6 board which already done as suggested..

-- 
Yixun Lan (dlan)

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

[Chukun Pan]

Hi,

> Just let me know if you guys want to do in another separate patch, so I could
> take this patch first, or want to squash together and send an incremental
> version? P.S checked k1-bananapi-cm6 board which already done as suggested..

I will send a separate patch for the MAC address.

Thanks,
Chukun