net: phy: add paged phy register accessors

Add a set of paged phy register accessors which are inherently safe in
their design against other accesses interfering with the paged access.

Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>
Reviewed-by: Andrew Lunn <andrew@lunn.ch>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/include/linux/phy.h b/include/linux/phy.h
index 0c5a285..af1a740 100644
--- a/include/linux/phy.h
+++ b/include/linux/phy.h
@@ -634,6 +634,9 @@ struct phy_driver {
 	int (*write_mmd)(struct phy_device *dev, int devnum, u16 regnum,
 			 u16 val);
 
+	int (*read_page)(struct phy_device *dev);
+	int (*write_page)(struct phy_device *dev, int page);
+
 	/* Get the size and type of the eeprom contained within a plug-in
 	 * module */
 	int (*module_info)(struct phy_device *dev,
@@ -838,6 +841,14 @@ static inline bool phy_is_pseudo_fixed_link(struct phy_device *phydev)
  */
 int phy_write_mmd(struct phy_device *phydev, int devad, u32 regnum, u16 val);
 
+int phy_save_page(struct phy_device *phydev);
+int phy_select_page(struct phy_device *phydev, int page);
+int phy_restore_page(struct phy_device *phydev, int oldpage, int ret);
+int phy_read_paged(struct phy_device *phydev, int page, u32 regnum);
+int phy_write_paged(struct phy_device *phydev, int page, u32 regnum, u16 val);
+int phy_modify_paged(struct phy_device *phydev, int page, u32 regnum,
+		     u16 mask, u16 set);
+
 struct phy_device *phy_device_create(struct mii_bus *bus, int addr, int phy_id,
 				     bool is_c45,
 				     struct phy_c45_device_ids *c45_ids);