net: phy: broadcom: support new device flag for setting master mode

Some of Broadcom's PHYs run by default in slave mode with Automatic
Slave/Master configuration disabled. It stops them from working properly
with some devices.

So far it has been verified for BCM54210E and BCM50212E which don't
work well with Intel's I217-LM and I218-LM:
http://ark.intel.com/products/60019/Intel-Ethernet-Connection-I217-LM
http://ark.intel.com/products/71307/Intel-Ethernet-Connection-I218-LM
I was told there is massive ping loss.

This commit adds support for a new flag which can be set by an ethernet
driver to fixup PHY setup.
Signed-off-by: Rafał Miłecki <rafal@milecki.pl>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/phy/broadcom.c

@@ -43,6 +43,12 @@ static int bcm54210e_config_init(struct phy_device *phydev)
 	val &= ~BCM54810_SHD_CLK_CTL_GTXCLK_EN;
 	bcm_phy_write_shadow(phydev, BCM54810_SHD_CLK_CTL, val);
 
+	if (phydev->dev_flags & PHY_BRCM_EN_MASTER_MODE) {
+		val = phy_read(phydev, MII_CTRL1000);
+		val |= CTL1000_AS_MASTER | CTL1000_ENABLE_MASTER;
+		phy_write(phydev, MII_CTRL1000, val);
+	}
+
 	return 0;
 }
 

include/linux/brcmphy.h

@@ -63,6 +63,7 @@
 #define PHY_BRCM_EXT_IBND_TX_ENABLE	0x00002000
 #define PHY_BRCM_CLEAR_RGMII_MODE	0x00004000
 #define PHY_BRCM_DIS_TXCRXC_NOENRGY	0x00008000
+#define PHY_BRCM_EN_MASTER_MODE		0x00010000
 
 /* Broadcom BCM7xxx specific workarounds */
 #define PHY_BRCM_7XXX_REV(x)		(((x) >> 8) & 0xff)