NET: Support clause 45 MDIO commands at the MDIO bus level

IEEE 802.3ae clause 45 specifies a somewhat modified MDIO protocol
for use by 10GIGE phys. The main change is a 21 bit address split into
a 5 bit device ID and a 16 bit register offset. The definition is designed
so that normal and extended devices can run on the same MDIO bus.

Extend mdio-bitbang to do the new protocol. At the MDIO bus level the
protocol is requested by or'ing MII_ADDR_C45 into the register offset.

Make phy_read/phy_write/etc pass a full 32 bit register offset.

This does not attempt to make the phy layer support C45 style PHYs, just
to provide the MDIO bus support.

Tested against a Broadcom 10GE phy with ID 0x206034, and several
Broadcom 10/100/1000 Phys in normal mode.

Signed-off-by: Jason Gunthorpe <jgunthorpe@obsidianresearch.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 8 insertions, 4 deletions

diff --git a/include/linux/phy.h b/include/linux/phy.h
index 14d7fdf6a90a..d9bce4b526b4 100644
--- a/include/linux/phy.h
+++ b/include/linux/phy.h
@@ -81,6 +81,10 @@ typedef enum {
  */
 #define MII_BUS_ID_SIZE (20 - 3)
 
+/* Or MII_ADDR_C45 into regnum for read/write on mii_bus to enable the 21 bit
+   IEEE 802.3ae clause 45 addressing mode used by 10GIGE phy chips. */
+#define MII_ADDR_C45 (1<<30)
+
 /*
  * The Bus class for PHYs.  Devices which provide access to
  * PHYs should register using this structure
@@ -127,8 +131,8 @@ int mdiobus_register(struct mii_bus *bus);
 void mdiobus_unregister(struct mii_bus *bus);
 void mdiobus_free(struct mii_bus *bus);
 struct phy_device *mdiobus_scan(struct mii_bus *bus, int addr);
-int mdiobus_read(struct mii_bus *bus, int addr, u16 regnum);
-int mdiobus_write(struct mii_bus *bus, int addr, u16 regnum, u16 val);
+int mdiobus_read(struct mii_bus *bus, int addr, u32 regnum);
+int mdiobus_write(struct mii_bus *bus, int addr, u32 regnum, u16 val);
 
 
 #define PHY_INTERRUPT_DISABLED  0x0
@@ -422,7 +426,7 @@ struct phy_fixup {
  * because the bus read/write functions may wait for an interrupt
  * to conclude the operation.
  */
-static inline int phy_read(struct phy_device *phydev, u16 regnum)
+static inline int phy_read(struct phy_device *phydev, u32 regnum)
 {
         return mdiobus_read(phydev->bus, phydev->addr, regnum);
 }
@@ -437,7 +441,7 @@ static inline int phy_read(struct phy_device *phydev, u16 regnum)
  * because the bus read/write functions may wait for an interrupt
  * to conclude the operation.
  */
-static inline int phy_write(struct phy_device *phydev, u16 regnum, u16 val)
+static inline int phy_write(struct phy_device *phydev, u32 regnum, u16 val)
 {
         return mdiobus_write(phydev->bus, phydev->addr, regnum, val);
 }