net: phy: add genphy_read_abilities

Similar to genphy_c45_pma_read_abilities() add a function to dynamically
detect the abilities of a Clause 22 PHY. This is mainly copied from
genphy_config_init().
Signed-off-by: Heiner Kallweit <hkallweit1@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/phy/phy_device.c

@@ -1880,6 +1880,54 @@ int genphy_config_init(struct phy_device *phydev)
 }
 EXPORT_SYMBOL(genphy_config_init);
 
+/**
+ * genphy_read_abilities - read PHY abilities from Clause 22 registers
+ * @phydev: target phy_device struct
+ *
+ * Description: Reads the PHY's abilities and populates
+ * phydev->supported accordingly.
+ *
+ * Returns: 0 on success, < 0 on failure
+ */
+int genphy_read_abilities(struct phy_device *phydev)
+{
+	int val;
+
+	linkmode_set_bit_array(phy_basic_ports_array,
+			       ARRAY_SIZE(phy_basic_ports_array),
+			       phydev->supported);
+
+	val = phy_read(phydev, MII_BMSR);
+	if (val < 0)
+		return val;
+
+	linkmode_mod_bit(ETHTOOL_LINK_MODE_Autoneg_BIT, phydev->supported,
+			 val & BMSR_ANEGCAPABLE);
+
+	linkmode_mod_bit(ETHTOOL_LINK_MODE_100baseT_Full_BIT, phydev->supported,
+			 val & BMSR_100FULL);
+	linkmode_mod_bit(ETHTOOL_LINK_MODE_100baseT_Half_BIT, phydev->supported,
+			 val & BMSR_100HALF);
+	linkmode_mod_bit(ETHTOOL_LINK_MODE_10baseT_Full_BIT, phydev->supported,
+			 val & BMSR_10FULL);
+	linkmode_mod_bit(ETHTOOL_LINK_MODE_10baseT_Half_BIT, phydev->supported,
+			 val & BMSR_10HALF);
+
+	if (val & BMSR_ESTATEN) {
+		val = phy_read(phydev, MII_ESTATUS);
+		if (val < 0)
+			return val;
+
+		linkmode_mod_bit(ETHTOOL_LINK_MODE_1000baseT_Full_BIT,
+				 phydev->supported, val & ESTATUS_1000_TFULL);
+		linkmode_mod_bit(ETHTOOL_LINK_MODE_1000baseT_Half_BIT,
+				 phydev->supported, val & ESTATUS_1000_THALF);
+	}
+
+	return 0;
+}
+EXPORT_SYMBOL(genphy_read_abilities);
+
 /* This is used for the phy device which doesn't support the MMD extended
  * register access, but it does have side effect when we are trying to access
  * the MMD register via indirect method.

include/linux/phy.h

@@ -1075,6 +1075,7 @@ void phy_attached_info(struct phy_device *phydev);
 
 /* Clause 22 PHY */
 int genphy_config_init(struct phy_device *phydev);
+int genphy_read_abilities(struct phy_device *phydev);
 int genphy_setup_forced(struct phy_device *phydev);
 int genphy_restart_aneg(struct phy_device *phydev);
 int genphy_config_eee_advert(struct phy_device *phydev);