[v2] arm64: dts: freescale: imx93-var-som: update eqos support for MaxLinear PHY

[Stefano Radaelli]

Variscite has updated the Ethernet PHY on the VAR-SOM-MX93 from the
Murata CYW43353 to the MaxLinear MXL86110, as documented in the
August 2023 revision changelog.
Link: https://variwiki.com/index.php?title=VAR-SOM-MX93_rev_changelog

Update the device tree accordingly:
- Drop the unused regulator node previously used to power the Murata PHY.
- Add support for the reset line using GPIO1_IO07 with proper timings.
- Configure the PHY LEDs via the LED subsystem under /sys/class/leds/,
  leveraging the support implemented in the mxl86110 PHY driver
  (drivers/net/phy/mxl-86110.c).
  Two LEDs are defined to match the LED configuration on the Variscite
  VAR-SOM Carrier Boards:
    * LED at 0: Yellow, netdev trigger.
    * LED at 1: Green, netdev trigger.
- Adjust the RGMII clock pad control settings to match the updated PHY
  requirements.

These changes ensure proper PHY initialization and LED status indication
for the new MaxLinear MXL86110, improving board compatibility with the
latest hardware revision.

Signed-off-by: Stefano Radaelli <stefano.radaelli21 at gmail.com>
---
v2:
  - Clarified the use of 'rgmii' mode by adding a comment in the DT,
    explaining that hardware delays are already implemented on the SOM PCB.

v1: https://lore.kernel.org/imx/20250603221416.74523-1-stefano.radaelli21@gmail.com/

 .../boot/dts/freescale/imx93-var-som.dtsi     | 45 ++++++++++++-------
 1 file changed, 30 insertions(+), 15 deletions(-)

diff --git a/arch/arm64/boot/dts/freescale/imx93-var-som.dtsi b/arch/arm64/boot/dts/freescale/imx93-var-som.dtsi
index 783938245e4f..cea8d792328c 100644
--- a/arch/arm64/boot/dts/freescale/imx93-var-som.dtsi
+++ b/arch/arm64/boot/dts/freescale/imx93-var-som.dtsi
@@ -19,26 +19,19 @@ mmc_pwrseq: mmc-pwrseq {
 		reset-gpios = <&gpio4 14 GPIO_ACTIVE_LOW>,	/* WIFI_RESET */
 			      <&gpio3 7 GPIO_ACTIVE_LOW>;	/* WIFI_PWR_EN */
 	};
-
-	reg_eqos_phy: regulator-eqos-phy {
-		compatible = "regulator-fixed";
-		pinctrl-names = "default";
-		pinctrl-0 = <&pinctrl_reg_eqos_phy>;
-		regulator-name = "eth_phy_pwr";
-		regulator-min-microvolt = <3300000>;
-		regulator-max-microvolt = <3300000>;
-		gpio = <&gpio1 7 GPIO_ACTIVE_HIGH>;
-		enable-active-high;
-		startup-delay-us = <100000>;
-		regulator-always-on;
-	};
 };
 
 &eqos {
 	pinctrl-names = "default";
 	pinctrl-0 = <&pinctrl_eqos>;
+	/*
+	 * The required RGMII TX and RX 2ns delays are implemented directly
+	 * in hardware via passive delay elements on the SOM PCB.
+	 * No delay configuration is needed in software via PHY driver.
+	 */
 	phy-mode = "rgmii";
 	phy-handle = <&ethphy0>;
+	snps,clk-csr = <5>;
 	status = "okay";
 
 	mdio {
@@ -51,6 +44,27 @@ ethphy0: ethernet-phy at 0 {
 			compatible = "ethernet-phy-ieee802.3-c22";
 			reg = <0>;
 			eee-broken-1000t;
+			reset-gpios = <&gpio1 7 GPIO_ACTIVE_LOW>;
+			reset-assert-us = <10000>;
+			reset-deassert-us = <100000>;
+			leds {
+				#address-cells = <1>;
+				#size-cells = <0>;
+
+				led at 0 {
+					reg = <0>;
+					color = <LED_COLOR_ID_YELLOW>;
+					function = LED_FUNCTION_LAN;
+					linux,default-trigger = "netdev";
+				};
+
+				led at 1 {
+					reg = <1>;
+					color = <LED_COLOR_ID_GREEN>;
+					function = LED_FUNCTION_LAN;
+					linux,default-trigger = "netdev";
+				};
+			};
 		};
 	};
 };
@@ -75,14 +89,15 @@ MX93_PAD_ENET1_RD0__ENET_QOS_RGMII_RD0			0x57e
 			MX93_PAD_ENET1_RD1__ENET_QOS_RGMII_RD1			0x57e
 			MX93_PAD_ENET1_RD2__ENET_QOS_RGMII_RD2			0x57e
 			MX93_PAD_ENET1_RD3__ENET_QOS_RGMII_RD3			0x57e
-			MX93_PAD_ENET1_RXC__CCM_ENET_QOS_CLOCK_GENERATE_RX_CLK	0x5fe
+			MX93_PAD_ENET1_RXC__CCM_ENET_QOS_CLOCK_GENERATE_RX_CLK	0x58e
 			MX93_PAD_ENET1_RX_CTL__ENET_QOS_RGMII_RX_CTL		0x57e
 			MX93_PAD_ENET1_TD0__ENET_QOS_RGMII_TD0			0x57e
 			MX93_PAD_ENET1_TD1__ENET_QOS_RGMII_TD1			0x57e
 			MX93_PAD_ENET1_TD2__ENET_QOS_RGMII_TD2			0x57e
 			MX93_PAD_ENET1_TD3__ENET_QOS_RGMII_TD3			0x57e
-			MX93_PAD_ENET1_TXC__CCM_ENET_QOS_CLOCK_GENERATE_TX_CLK	0x5fe
+			MX93_PAD_ENET1_TXC__CCM_ENET_QOS_CLOCK_GENERATE_TX_CLK	0x58e
 			MX93_PAD_ENET1_TX_CTL__ENET_QOS_RGMII_TX_CTL		0x57e
+			MX93_PAD_UART2_TXD__GPIO1_IO07				0x51e
 		>;
 	};
 

base-commit: a9dfb7db96f7bc1f30feae673aab7fdbfbc94e9c
prerequisite-patch-id: 2335ebcc90360b008c840e7edf7e34a595880edf
-- 
2.43.0