[netdrvr] gianfar: Determine TBIPA value dynamically

TBIPA needs to be set to a value (on connected MDIO buses) that
doesn't conflict with PHYs on the bus.  By hardcoding it to 0x1f,
we were preventing boards with PHYs at 0x1f from working properly.
Instead, scan the bus when it comes up, and find an address that
doesn't have a PHY on it.  The TBI PHY configuration code then
trusts that the value in TBIPA is either safe, or doesn't matter
(ie - it's not an active bus with other PHYs).

Signed-off-by: Andy Fleming <afleming@freescale.com>
Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
Signed-off-by: Jeff Garzik <jgarzik@redhat.com>

1 files changed, 14 insertions, 13 deletions

diff --git a/drivers/net/gianfar.c b/drivers/net/gianfar.c
index 99a4b990939f..587afe7be689 100644
--- a/drivers/net/gianfar.c
+++ b/drivers/net/gianfar.c
@@ -131,8 +131,6 @@ static void free_skb_resources(struct gfar_private *priv);
 static void gfar_set_multi(struct net_device *dev);
 static void gfar_set_hash_for_addr(struct net_device *dev, u8 *addr);
 static void gfar_configure_serdes(struct net_device *dev);
-extern int gfar_local_mdio_write(struct gfar_mii __iomem *regs, int mii_id, int regnum, u16 value);
-extern int gfar_local_mdio_read(struct gfar_mii __iomem *regs, int mii_id, int regnum);
 #ifdef CONFIG_GFAR_NAPI
 static int gfar_poll(struct napi_struct *napi, int budget);
 #endif
@@ -477,24 +475,30 @@ static int init_phy(struct net_device *dev)
         return 0;
 }
 
+/*
+ * Initialize TBI PHY interface for communicating with the
+ * SERDES lynx PHY on the chip.  We communicate with this PHY
+ * through the MDIO bus on each controller, treating it as a
+ * "normal" PHY at the address found in the TBIPA register.  We assume
+ * that the TBIPA register is valid.  Either the MDIO bus code will set
+ * it to a value that doesn't conflict with other PHYs on the bus, or the
+ * value doesn't matter, as there are no other PHYs on the bus.
+ */
 static void gfar_configure_serdes(struct net_device *dev)
 {
         struct gfar_private *priv = netdev_priv(dev);
         struct gfar_mii __iomem *regs =
                         (void __iomem *)&priv->regs->gfar_mii_regs;
+        int tbipa = gfar_read(&priv->regs->tbipa);
 
-        /* Initialise TBI i/f to communicate with serdes (lynx phy) */
+        /* Single clk mode, mii mode off(for serdes communication) */
+        gfar_local_mdio_write(regs, tbipa, MII_TBICON, TBICON_CLK_SELECT);
 
-        /* Single clk mode, mii mode off(for aerdes communication) */
-        gfar_local_mdio_write(regs, TBIPA_VALUE, MII_TBICON, TBICON_CLK_SELECT);
-
-        /* Supported pause and full-duplex, no half-duplex */
-        gfar_local_mdio_write(regs, TBIPA_VALUE, MII_ADVERTISE,
+        gfar_local_mdio_write(regs, tbipa, MII_ADVERTISE,
                         ADVERTISE_1000XFULL | ADVERTISE_1000XPAUSE |
                         ADVERTISE_1000XPSE_ASYM);
 
-        /* ANEG enable, restart ANEG, full duplex mode, speed[1] set */
-        gfar_local_mdio_write(regs, TBIPA_VALUE, MII_BMCR, BMCR_ANENABLE |
+        gfar_local_mdio_write(regs, tbipa, MII_BMCR, BMCR_ANENABLE |
                         BMCR_ANRESTART | BMCR_FULLDPLX | BMCR_SPEED1000);
 }
 
@@ -541,9 +545,6 @@ static void init_registers(struct net_device *dev)
 
         /* Initialize the Minimum Frame Length Register */
         gfar_write(&priv->regs->minflr, MINFLR_INIT_SETTINGS);
-
-        /* Assign the TBI an address which won't conflict with the PHYs */
-        gfar_write(&priv->regs->tbipa, TBIPA_VALUE);
 }