Hi list,

I want to apply a patch to the ethernet devices for the phy, where the patch looks like:
cat ../meta-mistysom/recipes-kernel/linux/smarc-rzg2l/0001-add-vsc8531-userspace-dts.patch
diff --git a/r9a07g044l2-smarc.dts.orig b/r9a07g044l2-smarc.dts
index bc2af6c..82ba67e 100644
--- a/arch/arm64/boot/dts/renesas/r9a07g044l2-smarc.dts
+++ b/arch/arm64/boot/dts/renesas/r9a07g044l2-smarc.dts
@@ -11,8 +11,32 @@
 #include "rzg2l-smarc-pinfunction.dtsi"
 #include "rz-smarc-common.dtsi"
 #include "rzg2l-smarc.dtsi"
+#include <dt-bindings/net/mscc-phy-vsc8531.h>

 / {
        model = "Renesas SMARC EVK based on r9a07g044l2";
        compatible = "renesas,smarc-evk", "renesas,r9a07g044l2", "renesas,r9a07g044";
 };
+
+&eth0 {
+        phy0: ethernet-phy@7 {
+                compatible = "ethernet-phy-ieee802.3-c45";
+                reg = <0>;
+                vsc8531,vddmac          = <1800>;
+                vsc8531,edge-slowdown   = <0>;
+                vsc8531,led-0-mode      = <VSC8531_LINK_1000_ACTIVITY>;
+                vsc8531,led-1-mode      = <VSC8531_LINK_100_ACTIVITY>;
+       };
+};
+
+&eth1 {
+        phy1: ethernet-phy@7 {
+                compatible = "ethernet-phy-ieee802.3-c45";
+                reg = <0>;
+                vsc8531,vddmac          = <1800>;
+                vsc8531,edge-slowdown   = <0>;
+                vsc8531,led-0-mode      = <VSC8531_LINK_1000_ACTIVITY>;
+                vsc8531,led-1-mode      = <VSC8531_LINK_100_ACTIVITY>;
+        };
+};
+

One question I have is, if the ampersand (&) should apply to the top eth node (as seen above) or the inner phy nodes, instead?, I only want to modify the phy settings.

When I boot the system with the kernel & device tree, on bootup I see the following messages:

[    6.721177] ravb 11c30000.ethernet eth1: failed to connect PHY
[    6.869282] ravb 11c20000.ethernet eth0: failed to connect PHY

and when I log in and check contents in /proc/device-tree/ I don't see any network interfaces.

I realized that dmesg also shows me:
mdio_bus 11c20000.ethernet-ffffffff: MDIO device at address 0 is missing.
and
mdio_bus 11c30000.ethernet-ffffffff: MDIO device at address 0 is missing.
while:
# mdio 11c20000.ethernet-ffffffff
 DEV      PHY-ID  LINK
0x00  0x00070572  up

i.e. once the system is booted, the PHYs are active and reachabele over MDIO.
The MDIO addresses are set to 0, both PHYs are connected to dedicated network (and MDIO) interfaces.

--
RON EGGLER Firmware Engineer (he/him/his) www.mistywest.com