net: phy: Add is_on_sfp_module flag and phy_on_sfp helper

Add a flag and helper function to indicate that a PHY device is part of
an SFP module, which is set on attach. This can be used by PHY drivers
to handle SFP-specific quirks or behavior.
Signed-off-by: Robert Hancock <robert.hancock@calian.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/phy/phy_device.c

@@ -1377,6 +1377,8 @@ int phy_attach_direct(struct net_device *dev, struct phy_device *phydev,
 
 		if (phydev->sfp_bus_attached)
 			dev->sfp_bus = phydev->sfp_bus;
+		else if (dev->sfp_bus)
+			phydev->is_on_sfp_module = true;
 	}
 
 	/* Some Ethernet drivers try to connect to a PHY device before

include/linux/phy.h

@@ -492,6 +492,7 @@ struct macsec_ops;
  * @sysfs_links: Internal boolean tracking sysfs symbolic links setup/removal.
  * @loopback_enabled: Set true if this PHY has been loopbacked successfully.
  * @downshifted_rate: Set true if link speed has been downshifted.
+ * @is_on_sfp_module: Set true if PHY is located on an SFP module.
  * @state: State of the PHY for management purposes
  * @dev_flags: Device-specific flags used by the PHY driver.
  * @irq: IRQ number of the PHY's interrupt (-1 if none)
@@ -565,6 +566,7 @@ struct phy_device {
 	unsigned sysfs_links:1;
 	unsigned loopback_enabled:1;
 	unsigned downshifted_rate:1;
+	unsigned is_on_sfp_module:1;
 
 	unsigned autoneg:1;
 	/* The most recently read link state */
@@ -1296,6 +1298,15 @@ static inline bool phy_is_internal(struct phy_device *phydev)
 	return phydev->is_internal;
 }
 
+/**
+ * phy_on_sfp - Convenience function for testing if a PHY is on an SFP module
+ * @phydev: the phy_device struct
+ */
+static inline bool phy_on_sfp(struct phy_device *phydev)
+{
+	return phydev->is_on_sfp_module;
+}
+
 /**
  * phy_interface_mode_is_rgmii - Convenience function for testing if a
  * PHY interface mode is RGMII (all variants)