Hi Sean

Just looking at the GPIO handling at the moment.

+	/* Reset whole chip through gpio pin or
+	 * memory-mapped registers for different
+	 * type of hardware
+	 */
+	if (priv->mcm) {
+		regmap_update_bits(priv->ethsys, SYSC_REG_RSTCTRL,
+				   RESET_MCM, RESET_MCM);
+		usleep_range(1000, 1100);
+		regmap_update_bits(priv->ethsys, SYSC_REG_RSTCTRL,
+				   RESET_MCM, ~RESET_MCM);
+	} else {
+		gpio_direction_output(priv->reset, 0);
+		usleep_range(1000, 1100);
+		gpio_set_value(priv->reset, 1);
+	}

....

+	/* Not MCM that indicates switch works as the remote standalone
+	 * integrated circuit so the GPIO pin would be used to complete
+	 * the reset, otherwise memory-mapped register accessing used
+	 * through syscon provides in the case of MCM.
+	 */
+	if (!priv->mcm) {
+		priv->reset = of_get_named_gpio(dn, "mediatek,reset-pin", 0);
+		if (!gpio_is_valid(priv->reset))
+			return priv->reset;
+
+		ret = devm_gpio_request_one(&mdiodev->dev,
+					    priv->reset, GPIOF_OUT_INIT_LOW,
+					    "mediatek,reset-pin");
+		if (ret < 0) {
+			dev_err(&mdiodev->dev,
+				"fail to devm_gpio_request reset\n");
+			return ret;
+		}
+	}

You are not handling the flags part of the GPIO binding. It is better
to use devm_gpiod_ API calls, which will handle the active low flags
for you.

    Andrew