igb: Add media switching feature for i354 PHY's

This patch adds a new feature which is supported in some PHY's on some i354
devices.  This feature is Auto Media Detect and allows which ever media is
detected first by the PHY to be the media used and configured by the
device.  This is a media swapping feature that is wholly contained in the
Marvell PHY.

Signed-off-by: Carolyn Wyborny <carolyn.wyborny@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>
diff --git a/drivers/net/ethernet/intel/igb/e1000_82575.c b/drivers/net/ethernet/intel/igb/e1000_82575.c
index 47c2d10..fe9db48 100644
--- a/drivers/net/ethernet/intel/igb/e1000_82575.c
+++ b/drivers/net/ethernet/intel/igb/e1000_82575.c
@@ -113,6 +113,59 @@
 }
 
 /**
+ *  igb_check_for_link_media_swap - Check which M88E1112 interface linked
+ *  @hw: pointer to the HW structure
+ *
+ *  Poll the M88E1112 interfaces to see which interface achieved link.
+ */
+static s32 igb_check_for_link_media_swap(struct e1000_hw *hw)
+{
+	struct e1000_phy_info *phy = &hw->phy;
+	s32 ret_val;
+	u16 data;
+	u8 port = 0;
+
+	/* Check the copper medium. */
+	ret_val = phy->ops.write_reg(hw, E1000_M88E1112_PAGE_ADDR, 0);
+	if (ret_val)
+		return ret_val;
+
+	ret_val = phy->ops.read_reg(hw, E1000_M88E1112_STATUS, &data);
+	if (ret_val)
+		return ret_val;
+
+	if (data & E1000_M88E1112_STATUS_LINK)
+		port = E1000_MEDIA_PORT_COPPER;
+
+	/* Check the other medium. */
+	ret_val = phy->ops.write_reg(hw, E1000_M88E1112_PAGE_ADDR, 1);
+	if (ret_val)
+		return ret_val;
+
+	ret_val = phy->ops.read_reg(hw, E1000_M88E1112_STATUS, &data);
+	if (ret_val)
+		return ret_val;
+
+	/* reset page to 0 */
+	ret_val = phy->ops.write_reg(hw, E1000_M88E1112_PAGE_ADDR, 0);
+	if (ret_val)
+		return ret_val;
+
+	if (data & E1000_M88E1112_STATUS_LINK)
+		port = E1000_MEDIA_PORT_OTHER;
+
+	/* Determine if a swap needs to happen. */
+	if (port && (hw->dev_spec._82575.media_port != port)) {
+		hw->dev_spec._82575.media_port = port;
+		hw->dev_spec._82575.media_changed = true;
+	} else {
+		ret_val = igb_check_for_link_82575(hw);
+	}
+
+	return E1000_SUCCESS;
+}
+
+/**
  *  igb_init_phy_params_82575 - Init PHY func ptrs.
  *  @hw: pointer to the HW structure
  **/
@@ -189,6 +242,29 @@
 		else
 			phy->ops.get_cable_length = igb_get_cable_length_m88;
 		phy->ops.force_speed_duplex = igb_phy_force_speed_duplex_m88;
+		/* Check if this PHY is confgured for media swap. */
+		if (phy->id == M88E1112_E_PHY_ID) {
+			u16 data;
+
+			ret_val = phy->ops.write_reg(hw,
+						     E1000_M88E1112_PAGE_ADDR,
+						     2);
+			if (ret_val)
+				goto out;
+
+			ret_val = phy->ops.read_reg(hw,
+						    E1000_M88E1112_MAC_CTRL_1,
+						    &data);
+			if (ret_val)
+				goto out;
+
+			data = (data & E1000_M88E1112_MAC_CTRL_1_MODE_MASK) >>
+			       E1000_M88E1112_MAC_CTRL_1_MODE_SHIFT;
+			if (data == E1000_M88E1112_AUTO_COPPER_SGMII ||
+			    data == E1000_M88E1112_AUTO_COPPER_BASEX)
+				hw->mac.ops.check_for_link =
+						igb_check_for_link_media_swap;
+		}
 		break;
 	case IGP03E1000_E_PHY_ID:
 		phy->type = e1000_phy_igp_3;