net: of_mdio: parse "max-speed" property to set PHY supported features

The "max-speed" property is defined per the ePAPR specification to
express the maximum speed a PHY supports. Use that property, if present
to set the phydev->supported features which properly restricts the PHY
within the range of defined speeds.

Signed-off-by: Florian Fainelli <f.fainelli@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 24 insertions, 1 deletions

diff --git a/drivers/of/of_mdio.c b/drivers/of/of_mdio.c
index 14feffc36964..a43b8523c61e 100644
--- a/drivers/of/of_mdio.c
+++ b/drivers/of/of_mdio.c
@@ -22,12 +22,30 @@
 MODULE_AUTHOR("Grant Likely <grant.likely@secretlab.ca>");
 MODULE_LICENSE("GPL");
 
+static void of_set_phy_supported(struct phy_device *phydev, u32 max_speed)
+{
+        phydev->supported |= PHY_DEFAULT_FEATURES;
+
+        switch (max_speed) {
+        default:
+                return;
+
+        case SPEED_1000:
+                phydev->supported |= PHY_1000BT_FEATURES;
+        case SPEED_100:
+                phydev->supported |= PHY_100BT_FEATURES;
+        case SPEED_10:
+                phydev->supported |= PHY_10BT_FEATURES;
+        }
+}
+
 static int of_mdiobus_register_phy(struct mii_bus *mdio, struct device_node *child,
                                    u32 addr)
 {
         struct phy_device *phy;
         bool is_c45;
         int rc, prev_irq;
+        u32 max_speed = 0;
 
         is_c45 = of_device_is_compatible(child,
                                          "ethernet-phy-ieee802.3-c45");
@@ -58,8 +76,13 @@ static int of_mdiobus_register_phy(struct mii_bus *mdio, struct device_node *chi
                 return 1;
         }
 
+        /* Set phydev->supported based on the "max-speed" property
+         * if present */
+        if (!of_property_read_u32(child, "max-speed", &max_speed))
+                of_set_phy_supported(phy, max_speed);
+
         dev_dbg(&mdio->dev, "registered phy %s at address %i\n",
-                 child->name, addr);
+                child->name, addr);
 
         return 0;
 }