net: phy: qcom: qca808x: add helper for checking for 1G only model

There are 2 versions of QCA808x, one 2.5G capable and one 1G capable.
Currently, this matter only in the .get_features call however, it will
be required for filling supported interface modes so lets add a helper
that can be reused.
Signed-off-by: Robert Marko <robimarko@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/phy/qcom/qca808x.c

@@ -156,6 +156,17 @@ static bool qca808x_has_fast_retrain_or_slave_seed(struct phy_device *phydev)
 	return linkmode_test_bit(ETHTOOL_LINK_MODE_2500baseT_Full_BIT, phydev->supported);
 }
 
+static bool qca808x_is_1g_only(struct phy_device *phydev)
+{
+	int ret;
+
+	ret = phy_read_mmd(phydev, MDIO_MMD_AN, QCA808X_PHY_MMD7_CHIP_TYPE);
+	if (ret < 0)
+		return true;
+
+	return !!(QCA808X_PHY_CHIP_TYPE_1G & ret);
+}
+
 static int qca808x_probe(struct phy_device *phydev)
 {
 	struct device *dev = &phydev->mdio.dev;
@@ -350,11 +361,7 @@ static int qca808x_get_features(struct phy_device *phydev)
 	 * existed in the bit0 of MMD1.21, we need to remove it manually if
 	 * it is the qca8081 1G chip according to the bit0 of MMD7.0x901d.
 	 */
-	ret = phy_read_mmd(phydev, MDIO_MMD_AN, QCA808X_PHY_MMD7_CHIP_TYPE);
-	if (ret < 0)
-		return ret;
-
-	if (QCA808X_PHY_CHIP_TYPE_1G & ret)
+	if (qca808x_is_1g_only(phydev))
 		linkmode_clear_bit(ETHTOOL_LINK_MODE_2500baseT_Full_BIT, phydev->supported);
 
 	return 0;