Re: [PATCH v2 net-next] net: phy: mchp: Add 1588 support for LAN8814 Quad PHY

+static int lan8814_read_page_reg(struct phy_device *phydev,
+				 int page, u32 addr)
+{
+	u32 data;
+
+	phy_write(phydev, KSZ_EXT_PAGE_ACCESS_CONTROL, page);
+	phy_write(phydev, KSZ_EXT_PAGE_ACCESS_ADDRESS_DATA, addr);
+	phy_write(phydev, KSZ_EXT_PAGE_ACCESS_CONTROL, (page | 0x4000));
+	data = phy_read(phydev, KSZ_EXT_PAGE_ACCESS_ADDRESS_DATA);
+
+	return data;
+}
+
+static int lan8814_write_page_reg(struct phy_device *phydev,
+				  int page, u16 addr, u16 val)
+{
+	phy_write(phydev, KSZ_EXT_PAGE_ACCESS_CONTROL, page);
+	phy_write(phydev, KSZ_EXT_PAGE_ACCESS_ADDRESS_DATA, addr);
+	phy_write(phydev, KSZ_EXT_PAGE_ACCESS_CONTROL, (page | 0x4000));
+	val = phy_write(phydev, KSZ_EXT_PAGE_ACCESS_ADDRESS_DATA, val);
+	if (val != 0) {
+		phydev_err(phydev, "Error: phy_write_mmd has returned error %d\n",
+			   val);
+		return val;
+	}
+	return 0;
+}

I think you can just use phy_read_mmd() and phy_write_mmd().

  Andrew