broadcom: Refine expansion register access routine

This patch makes the expansion register access routines a little more
formal.  They will be used by the following bcm50610 support patch.

Signed-off-by: Matt Carlson <mcarlson@broadcom.com>
Signed-off-by: Michael Chan <mchan@broadcom.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 34 insertions, 26 deletions

diff --git a/drivers/net/phy/broadcom.c b/drivers/net/phy/broadcom.c
index 0fe37492feb1..7e935924793d 100644
--- a/drivers/net/phy/broadcom.c
+++ b/drivers/net/phy/broadcom.c
@@ -128,36 +128,35 @@ static int bcm54xx_shadow_write(struct phy_device *phydev, u16 shadow, u16 val)
                          MII_BCM54XX_SHD_DATA(val));
 }
 
-/*
- * Indirect register access functions for the Expansion Registers
- * and Secondary SerDes registers (when sec_serdes=1).
- */
-static int bcm54xx_exp_read(struct phy_device *phydev,
-                            int sec_serdes, u8 regnum)
+/* Indirect register access functions for the Expansion Registers */
+static int bcm54xx_exp_read(struct phy_device *phydev, u8 regnum)
 {
         int val;
 
-        phy_write(phydev, MII_BCM54XX_EXP_SEL,
-                  (sec_serdes ? MII_BCM54XX_EXP_SEL_SSD :
-                                MII_BCM54XX_EXP_SEL_ER) |
-                  regnum);
+        val = phy_write(phydev, MII_BCM54XX_EXP_SEL, regnum);
+        if (val < 0)
+                return val;
+
         val = phy_read(phydev, MII_BCM54XX_EXP_DATA);
-        phy_write(phydev, MII_BCM54XX_EXP_SEL, regnum);
+
+        /* Restore default value.  It's O.K. if this write fails. */
+        phy_write(phydev, MII_BCM54XX_EXP_SEL, 0);
 
         return val;
 }
 
-static int bcm54xx_exp_write(struct phy_device *phydev,
-                             int sec_serdes, u8 regnum, u16 val)
+static int bcm54xx_exp_write(struct phy_device *phydev, u8 regnum, u16 val)
 {
         int ret;
 
-        phy_write(phydev, MII_BCM54XX_EXP_SEL,
-                  (sec_serdes ? MII_BCM54XX_EXP_SEL_SSD :
-                                MII_BCM54XX_EXP_SEL_ER) |
-                  regnum);
+        ret = phy_write(phydev, MII_BCM54XX_EXP_SEL, regnum);
+        if (ret < 0)
+                return ret;
+
         ret = phy_write(phydev, MII_BCM54XX_EXP_DATA, val);
-        phy_write(phydev, MII_BCM54XX_EXP_SEL, regnum);
+
+        /* Restore default value.  It's O.K. if this write fails. */
+        phy_write(phydev, MII_BCM54XX_EXP_SEL, 0);
 
         return ret;
 }
@@ -205,18 +204,27 @@ static int bcm5482_config_init(struct phy_device *phydev)
                 /*
                  * Enable SGMII slave mode and auto-detection
                  */
-                reg = bcm54xx_exp_read(phydev, 1, BCM5482_SSD_SGMII_SLAVE);
-                bcm54xx_exp_write(phydev, 1, BCM5482_SSD_SGMII_SLAVE,
-                                  reg |
-                                  BCM5482_SSD_SGMII_SLAVE_EN |
-                                  BCM5482_SSD_SGMII_SLAVE_AD);
+                reg = BCM5482_SSD_SGMII_SLAVE | MII_BCM54XX_EXP_SEL_SSD;
+                err = bcm54xx_exp_read(phydev, reg);
+                if (err < 0)
+                        return err;
+                err = bcm54xx_exp_write(phydev, reg, err |
+                                        BCM5482_SSD_SGMII_SLAVE_EN |
+                                        BCM5482_SSD_SGMII_SLAVE_AD);
+                if (err < 0)
+                        return err;
 
                 /*
                  * Disable secondary SerDes powerdown
                  */
-                reg = bcm54xx_exp_read(phydev, 1, BCM5482_SSD_1000BX_CTL);
-                bcm54xx_exp_write(phydev, 1, BCM5482_SSD_1000BX_CTL,
-                                  reg & ~BCM5482_SSD_1000BX_CTL_PWRDOWN);
+                reg = BCM5482_SSD_1000BX_CTL | MII_BCM54XX_EXP_SEL_SSD;
+                err = bcm54xx_exp_read(phydev, reg);
+                if (err < 0)
+                        return err;
+                err = bcm54xx_exp_write(phydev, reg,
+                                        err & ~BCM5482_SSD_1000BX_CTL_PWRDOWN);
+                if (err < 0)
+                        return err;
 
                 /*
                  * Select 1000BASE-X register set (primary SerDes)