net: phy: broadcom: Fix bcm_write_exp()

On newer PHYs, we need to select the expansion register to write with
setting bits [11:8] to 0xf. This was done correctly by bcm7xxx.c prior
to being migrated to generic code under bcm-phy-lib.c which
unfortunately used the older implementation from the BCM54xx days.

Fix this by creating an inline stub: bcm_write_exp_sel() which adds the
correct value (MII_BCM54XX_EXP_SEL_ER) and update both the Cygnus PHY
and BCM7xxx PHY drivers which require setting these bits.

broadcom.c is unchanged because some PHYs even use a different selector
method, so let them specify it directly (e.g: SerDes secondary selector).

Fixes: a1cba5613edf ("net: phy: Add Broadcom phy library for common interfaces")
Signed-off-by: Florian Fainelli <f.fainelli@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 7 insertions, 0 deletions

diff --git a/drivers/net/phy/bcm-phy-lib.h b/drivers/net/phy/bcm-phy-lib.h
index 7c73808cbbde..81cceaa412fe 100644
--- a/drivers/net/phy/bcm-phy-lib.h
+++ b/drivers/net/phy/bcm-phy-lib.h
@@ -14,11 +14,18 @@
 #ifndef _LINUX_BCM_PHY_LIB_H
 #define _LINUX_BCM_PHY_LIB_H
 
+#include <linux/brcmphy.h>
 #include <linux/phy.h>
 
 int bcm_phy_write_exp(struct phy_device *phydev, u16 reg, u16 val);
 int bcm_phy_read_exp(struct phy_device *phydev, u16 reg);
 
+static inline int bcm_phy_write_exp_sel(struct phy_device *phydev,
+					u16 reg, u16 val)
+{
+	return bcm_phy_write_exp(phydev, reg | MII_BCM54XX_EXP_SEL_ER, val);
+}
+
 int bcm54xx_auxctl_write(struct phy_device *phydev, u16 regnum, u16 val);
 int bcm54xx_auxctl_read(struct phy_device *phydev, u16 regnum);