phylink,sfp: negotiate interface format with MAC

Negotiate the interface format with the MAC rather than requiring it to
be a fixed type specified solely by the SFP module.  This allows modules
that can work with several different interface signalling formats to
select a format compatible with the MAC - for example, a Fiber module
supporing Gigabit ethernet and faster connected to a Gigabit only MAC
needs to select the 1000BASE-X mode.

Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 39 insertions, 62 deletions

diff --git a/drivers/net/phy/sfp-bus.c b/drivers/net/phy/sfp-bus.c
index 15749428679e..3d4ff5d0d2a6 100644
--- a/drivers/net/phy/sfp-bus.c
+++ b/drivers/net/phy/sfp-bus.c
@@ -106,68 +106,6 @@ int sfp_parse_port(struct sfp_bus *bus, const struct sfp_eeprom_id *id,
 EXPORT_SYMBOL_GPL(sfp_parse_port);
 
 /**
- * sfp_parse_interface() - Parse the phy_interface_t
- * @bus: a pointer to the &struct sfp_bus structure for the sfp module
- * @id: a pointer to the module's &struct sfp_eeprom_id
- *
- * Derive the phy_interface_t mode for the information found in the
- * module's identifying EEPROM. There is no standard or defined way
- * to derive this information, so we use some heuristics.
- *
- * If the encoding is 64b66b, then the module must be >= 10G, so
- * return %PHY_INTERFACE_MODE_10GKR.
- *
- * If it's 8b10b, then it's 1G or slower. If it's definitely a fibre
- * module, return %PHY_INTERFACE_MODE_1000BASEX mode, otherwise return
- * %PHY_INTERFACE_MODE_SGMII mode.
- *
- * If the encoding is not known, return %PHY_INTERFACE_MODE_NA.
- */
-phy_interface_t sfp_parse_interface(struct sfp_bus *bus,
-				    const struct sfp_eeprom_id *id)
-{
-	phy_interface_t iface;
-
-	/* Setting the serdes link mode is guesswork: there's no field in
-	 * the EEPROM which indicates what mode should be used.
-	 *
-	 * If the module wants 64b66b, then it must be >= 10G.
-	 *
-	 * If it's a gigabit-only fiber module, it probably does not have
-	 * a PHY, so switch to 802.3z negotiation mode. Otherwise, switch
-	 * to SGMII mode (which is required to support non-gigabit speeds).
-	 */
-	switch (id->base.encoding) {
-	case SFP_ENCODING_8472_64B66B:
-		iface = PHY_INTERFACE_MODE_10GKR;
-		break;
-
-	case SFP_ENCODING_8B10B:
-		if (!id->base.e1000_base_t &&
-		    !id->base.e100_base_lx &&
-		    !id->base.e100_base_fx)
-			iface = PHY_INTERFACE_MODE_1000BASEX;
-		else
-			iface = PHY_INTERFACE_MODE_SGMII;
-		break;
-
-	default:
-		if (id->base.e1000_base_cx) {
-			iface = PHY_INTERFACE_MODE_1000BASEX;
-			break;
-		}
-
-		iface = PHY_INTERFACE_MODE_NA;
-		dev_err(bus->sfp_dev,
-			"SFP module encoding does not support 8b10b nor 64b66b\n");
-		break;
-	}
-
-	return iface;
-}
-EXPORT_SYMBOL_GPL(sfp_parse_interface);
-
-/**
  * sfp_parse_support() - Parse the eeprom id for supported link modes
  * @bus: a pointer to the &struct sfp_bus structure for the sfp module
  * @id: a pointer to the module's &struct sfp_eeprom_id
@@ -296,6 +234,45 @@ void sfp_parse_support(struct sfp_bus *bus, const struct sfp_eeprom_id *id,
 }
 EXPORT_SYMBOL_GPL(sfp_parse_support);
 
+/**
+ * sfp_select_interface() - Select appropriate phy_interface_t mode
+ * @bus: a pointer to the &struct sfp_bus structure for the sfp module
+ * @id: a pointer to the module's &struct sfp_eeprom_id
+ * @link_modes: ethtool link modes mask
+ *
+ * Derive the phy_interface_t mode for the information found in the
+ * module's identifying EEPROM and the link modes mask. There is no
+ * standard or defined way to derive this information, so we decide
+ * based upon the link mode mask.
+ */
+phy_interface_t sfp_select_interface(struct sfp_bus *bus,
+				     const struct sfp_eeprom_id *id,
+				     unsigned long *link_modes)
+{
+	if (phylink_test(link_modes, 10000baseCR_Full) ||
+	    phylink_test(link_modes, 10000baseSR_Full) ||
+	    phylink_test(link_modes, 10000baseLR_Full) ||
+	    phylink_test(link_modes, 10000baseLRM_Full) ||
+	    phylink_test(link_modes, 10000baseER_Full))
+		return PHY_INTERFACE_MODE_10GKR;
+
+	if (phylink_test(link_modes, 2500baseX_Full))
+		return PHY_INTERFACE_MODE_2500BASEX;
+
+	if (id->base.e1000_base_t ||
+	    id->base.e100_base_lx ||
+	    id->base.e100_base_fx)
+		return PHY_INTERFACE_MODE_SGMII;
+
+	if (phylink_test(link_modes, 1000baseX_Full))
+		return PHY_INTERFACE_MODE_1000BASEX;
+
+	dev_warn(bus->sfp_dev, "Unable to ascertain link mode\n");
+
+	return PHY_INTERFACE_MODE_NA;
+}
+EXPORT_SYMBOL_GPL(sfp_select_interface);
+
 static LIST_HEAD(sfp_buses);
 static DEFINE_MUTEX(sfp_mutex);