mx6cuboxi: Fix Ethernet after DT sync with Linux

The i.MX6 Cubox-i and HummingBoards can have different PHYs at varying
addresses. U-Boot needs to auto-detect which phy is actually present,
and at which address it is responding.

Auto-detection from multiple phy nodes specified in device-tree does not
currently work correct. As a work-around merge all three possible phys
into one node with the special address 0xffffffff which indicates to the
generic phy driver to probe all addresses.

Signed-off-by: Josua Mayer <josua@solid-run.com>
[fabio: Added the changes to imx6qdl-sr-som-u-boot.dtsi.]
Signed-off-by: Fabio Estevam <festevam@gmail.com>
Tested-by: Christian Gmeiner <cgmeiner@igalia.com>
Tested-by: Christian Gmeiner <cgmeiner@igalia.com>

arch/arm/dts/imx6qdl-hummingboard2-emmc-som-v15-u-boot.dtsi

@@ -1,6 +1,7 @@
 // SPDX-License-Identifier: GPL-2.0+
 
 #include "imx6qdl-u-boot.dtsi"
+#include "imx6qdl-sr-som-u-boot.dtsi"
 
 / {
 	board-detect {

arch/arm/dts/imx6qdl-sr-som-u-boot.dtsi

@@ -0,0 +1,49 @@
+// SPDX-License-Identifier: (GPL-2.0 OR MIT)
+
+#include <dt-bindings/gpio/gpio.h>
+
+&fec {
+	pinctrl-names = "default";
+	pinctrl-0 = <&pinctrl_microsom_enet_ar8035>;
+	phy-handle = <&phy>;
+	phy-mode = "rgmii-id";
+
+	/*
+	 * The PHY seems to require a long-enough reset duration to avoid
+	 * some rare issues where the PHY gets stuck in an inconsistent and
+	 * non-functional state at boot-up. 10ms proved to be fine .
+	 */
+	phy-reset-duration = <10>;
+	phy-reset-gpios = <&gpio4 15 GPIO_ACTIVE_LOW>;
+	status = "okay";
+
+	mdio {
+		#address-cells = <1>;
+		#size-cells = <0>;
+
+		ethernet-phy@0 {
+			status = "disabled";
+		};
+
+		ethernet-phy@1 {
+			status = "disabled";
+		};
+
+		ethernet-phy@4 {
+			status = "disabled";
+		};
+
+		phy: ethernet-phy@ffffffff {
+			/*
+			 * The PHY can appear either:
+			 * - AR8035: at address 0 or 4
+			 * - ADIN1300: at address 1
+			 * Actual address being detected at runtime.
+			 */
+			reg = <0xffffffff>;
+			qca,clk-out-frequency = <125000000>;
+			qca,smarteee-tw-us-1g = <24>;
+			adi,phy-output-clock = "125mhz-free-running";
+		};
+	};
+};