Thread (10 messages) 10 messages, 5 authors, 2025-06-11

Re: [PATCH v3 3/3] ARM: dts: microchip: sama5d27_wlsom1: Add nvmem-layout in QSPI for EUI48 MAC Address

From: Tudor Ambarus <tudor.ambarus@linaro.org>
Date: 2025-06-09 08:17:53
Also in: linux-devicetree, lkml


On 5/21/25 8:03 AM, Manikandan Muralidharan wrote:
quoted hunk ↗ jump to hunk
Add nvmem-layout in QSPI to read the EUI48 Mac address by the
net drivers using the nvmem property.The offset is set to 0x0
since the factory programmed address is available in the
resource managed space and the size determine if the requested
address is of EUI48 (0x6) or EUI-64 (0x8) type.
This is useful for cases where U-Boot is skipped and the Ethernet
MAC address is needed to be configured by the kernel

Signed-off-by: Manikandan Muralidharan <manikandan.m@microchip.com>
---
 .../boot/dts/microchip/at91-sama5d27_wlsom1.dtsi    | 13 +++++++++++++
 1 file changed, 13 insertions(+)
diff --git a/arch/arm/boot/dts/microchip/at91-sama5d27_wlsom1.dtsi b/arch/arm/boot/dts/microchip/at91-sama5d27_wlsom1.dtsi
index b34c5072425a..be06df1b7d66 100644
--- a/arch/arm/boot/dts/microchip/at91-sama5d27_wlsom1.dtsi
+++ b/arch/arm/boot/dts/microchip/at91-sama5d27_wlsom1.dtsi
@@ -210,6 +210,9 @@ &macb0 {
 	#size-cells = <0>;
 	phy-mode = "rmii";
 
+	nvmem-cells = <&mac_address_eui48>;
+	nvmem-cell-names = "mac-address";
+
 	ethernet-phy@0 {
 		reg = <0x0>;
 		interrupt-parent = <&pioA>;
@@ -238,6 +241,16 @@ qspi1_flash: flash@0 {
 		m25p,fast-read;
 		status = "disabled";
 
+		nvmem-layout {
+			compatible = "fixed-layout";
+			#address-cells = <1>;
+			#size-cells = <1>;
+
+			mac_address_eui48: mac-address@0 {
+				reg = <0x0 0x6>;
+			};
How would this work if in the future the mchp vendor table adds some
other info that needs to be referenced as nvmem? How do you distinguish
the info from the table?
Would it be possible to have some kind of address and size to reference
the SFDP?
+		};
+
 		partitions {
 			compatible = "fixed-partitions";
 			#address-cells = <1>;
  
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