net: phy: realtek: add support for EEE registers on integrated PHY's

EEE-related registers on newer integrated PHY's have the standard
layout, but are accessible not via MMD but via vendor-specific
registers. Emulating the standard MMD registers allows to use the
generic functions for EEE control.
Signed-off-by: Heiner Kallweit <hkallweit1@gmail.com>
Reviewed-by: Florian Fainelli <f.fainelli@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/phy/realtek.c

@@ -266,6 +266,45 @@ static int rtl8366rb_config_init(struct phy_device *phydev)
 	return ret;
 }
 
+static int rtlgen_read_mmd(struct phy_device *phydev, int devnum, u16 regnum)
+{
+	int ret;
+
+	if (devnum == MDIO_MMD_PCS && regnum == MDIO_PCS_EEE_ABLE) {
+		rtl821x_write_page(phydev, 0xa5c);
+		ret = __phy_read(phydev, 0x12);
+		rtl821x_write_page(phydev, 0);
+	} else if (devnum == MDIO_MMD_AN && regnum == MDIO_AN_EEE_ADV) {
+		rtl821x_write_page(phydev, 0xa5d);
+		ret = __phy_read(phydev, 0x10);
+		rtl821x_write_page(phydev, 0);
+	} else if (devnum == MDIO_MMD_AN && regnum == MDIO_AN_EEE_LPABLE) {
+		rtl821x_write_page(phydev, 0xa5d);
+		ret = __phy_read(phydev, 0x11);
+		rtl821x_write_page(phydev, 0);
+	} else {
+		ret = -EOPNOTSUPP;
+	}
+
+	return ret;
+}
+
+static int rtlgen_write_mmd(struct phy_device *phydev, int devnum, u16 regnum,
+			    u16 val)
+{
+	int ret;
+
+	if (devnum == MDIO_MMD_AN && regnum == MDIO_AN_EEE_ADV) {
+		rtl821x_write_page(phydev, 0xa5d);
+		ret = __phy_write(phydev, 0x10, val);
+		rtl821x_write_page(phydev, 0);
+	} else {
+		ret = -EOPNOTSUPP;
+	}
+
+	return ret;
+}
+
 static int rtl8125_get_features(struct phy_device *phydev)
 {
 	int val;
@@ -422,6 +461,8 @@ static struct phy_driver realtek_drvs[] = {
 		.resume		= genphy_resume,
 		.read_page	= rtl821x_read_page,
 		.write_page	= rtl821x_write_page,
+		.read_mmd	= rtlgen_read_mmd,
+		.write_mmd	= rtlgen_write_mmd,
 	}, {
 		.name		= "RTL8125 2.5Gbps internal",
 		.match_phy_device = rtl8125_match_phy_device,
@@ -432,6 +473,8 @@ static struct phy_driver realtek_drvs[] = {
 		.resume		= genphy_resume,
 		.read_page	= rtl821x_read_page,
 		.write_page	= rtl821x_write_page,
+		.read_mmd	= rtlgen_read_mmd,
+		.write_mmd	= rtlgen_write_mmd,
 	}, {
 		PHY_ID_MATCH_EXACT(0x001cc961),
 		.name		= "RTL8366RB Gigabit Ethernet",