[PATCH] ARM: dts: BCM5301X: AC56U: set WAN MAC from nvram

From: Rosen Penev

Date: Wed Aug 05 2026 - 15:03:27 EST


The WAN MAC is offset by 1. Set in dts to avoid having to handle this in
userspace.

nvram size found from a random bootlog online.

Signed-off-by: Rosen Penev <rosenp@xxxxxxxxx>
---
.../dts/broadcom/bcm4708-asus-rt-ac56u.dts | 55 +++++++++++++++++++
1 file changed, 55 insertions(+)

diff --git a/arch/arm/boot/dts/broadcom/bcm4708-asus-rt-ac56u.dts b/arch/arm/boot/dts/broadcom/bcm4708-asus-rt-ac56u.dts
index c80ac16ad949..df59136b076c 100644
--- a/arch/arm/boot/dts/broadcom/bcm4708-asus-rt-ac56u.dts
+++ b/arch/arm/boot/dts/broadcom/bcm4708-asus-rt-ac56u.dts
@@ -25,6 +25,15 @@ memory@0 {
<0x88000000 0x08000000>;
};

+ nvram@1c080000 {
+ compatible = "brcm,nvram";
+ reg = <0x1c080000 0x180000>;
+
+ et0macaddr: et0macaddr {
+ #nvmem-cell-cells = <1>;
+ };
+ };
+
leds {
compatible = "gpio-leds";

@@ -92,3 +101,49 @@ button-wps {
&usb3_phy {
status = "okay";
};
+
+&gmac0 {
+ nvmem-cells = <&et0macaddr 0>;
+ nvmem-cell-names = "mac-address";
+};
+
+&srab {
+ status = "okay";
+
+ ports {
+ port@0 {
+ label = "lan1";
+ };
+
+ port@1 {
+ label = "lan2";
+ };
+
+ port@2 {
+ label = "lan3";
+ };
+
+ port@3 {
+ label = "lan4";
+ };
+
+ port@4 {
+ label = "wan";
+
+ nvmem-cells = <&et0macaddr 1>;
+ nvmem-cell-names = "mac-address";
+ };
+
+ port@5 {
+ label = "cpu";
+ };
+
+ port@7 {
+ status = "disabled";
+ };
+
+ port@8 {
+ status = "disabled";
+ };
+ };
+};
--
2.55.0