net: phy: report link partner features through ethtool

The PHY library already reads the MII_STAT1000 and MII_LPA registers in
genphy_read_status(), so extend it to also populate the PHY device link
partner advertised features such that we can feed this back into ethtool
when asked for it in phy_ethtool_gset().
Signed-off-by: Florian Fainelli <f.fainelli@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/phy/phy.c

@@ -289,6 +289,7 @@ int phy_ethtool_gset(struct phy_device *phydev, struct ethtool_cmd *cmd)
 	cmd->supported = phydev->supported;
 
 	cmd->advertising = phydev->advertising;
+	cmd->lp_advertising = phydev->lp_advertising;
 
 	ethtool_cmd_speed_set(cmd, phydev->speed);
 	cmd->duplex = phydev->duplex;

drivers/net/phy/phy_device.c

@@ -839,6 +839,8 @@ int genphy_read_status(struct phy_device *phydev)
 	if (err)
 		return err;
 
+	phydev->lp_advertising = 0;
+
 	if (AUTONEG_ENABLE == phydev->autoneg) {
 		if (phydev->supported & (SUPPORTED_1000baseT_Half
 					| SUPPORTED_1000baseT_Full)) {
@@ -852,6 +854,8 @@ int genphy_read_status(struct phy_device *phydev)
 			if (adv < 0)
 				return adv;
 
+			phydev->lp_advertising =
+				mii_stat1000_to_ethtool_lpa_t(lpagb);
 			lpagb &= adv << 2;
 		}
 
@@ -860,6 +864,8 @@ int genphy_read_status(struct phy_device *phydev)
 		if (lpa < 0)
 			return lpa;
 
+		phydev->lp_advertising |= mii_lpa_to_ethtool_lpa_t(lpa);
+
 		adv = phy_read(phydev, MII_ADVERTISE);
 
 		if (adv < 0)

include/linux/phy.h

@@ -287,8 +287,8 @@ struct phy_c45_device_ids {
  * adjust_state: Callback for the enet driver to respond to
  * changes in the state machine.
  *
- * speed, duplex, pause, supported, advertising, and
- * autoneg are used like in mii_if_info
+ * speed, duplex, pause, supported, advertising, lp_advertising,
+ * and autoneg are used like in mii_if_info
  *
  * interrupts currently only supports enabled or disabled,
  * but could be changed in the future to support enabling
@@ -340,6 +340,7 @@ struct phy_device {
 	/* See mii.h for more info */
 	u32 supported;
 	u32 advertising;
+	u32 lp_advertising;
 
 	int autoneg;