+static int at8035_parse_dt(struct phy_device *phydev)
+{
+	struct device_node *node = phydev->mdio.dev.of_node;
+	struct at803x_priv *priv = phydev->priv;
+	u32 freq;
+	int ret;
+
+	if (!IS_ENABLED(CONFIG_OF_MDIO))
+		return 0;
+
+	ret = of_property_read_u32(node, "qca,clk-out-frequency", &freq);
+	if (!ret) {

I don't think you need this. priv->clk_25m_reg and priv->clk_25m_mask
will default to 0. If qca,clk-out-frequency does not exist, they will
still be zero....

+		/* Fixup for the AR8030/AR8035. This chip has another mask and
+		 * doesn't support the DSP reference. Eg. the lowest bit of the
+		 * mask. The upper two bits select the same frequencies. Mask
+		 * the lowest bit here.
+		 *
+		 * Warning:
+		 *   There was no datasheet for the AR8030 available so this is
+		 *   just a guess. But the AR8035 is listed as pin compatible
+		 *   to the AR8030 so there might be a good chance it works on
+		 *   the AR8030 too.
+		 */
+		priv->clk_25m_reg &= AT8035_CLK_OUT_MASK;
+		priv->clk_25m_mask &= AT8035_CLK_OUT_MASK;

... so applying a mask to 0 does nothing.

It does change the code a little, but you can add a justification in
the commit message.

    Andrew