3 files changed, 112 insertions, 0 deletions

diff --git a/Documentation/devicetree/bindings/net/fixed-link.txt b/Documentation/devicetree/bindings/net/fixed-link.txt
new file mode 100644
index 000000000000..e956de1be935
--- /dev/null
+++ b/Documentation/devicetree/bindings/net/fixed-link.txt
@@ -0,0 +1,30 @@
+Fixed link Device Tree binding
+------------------------------
+
+Some Ethernet MACs have a "fixed link", and are not connected to a
+normal MDIO-managed PHY device. For those situations, a Device Tree
+binding allows to describe a "fixed link".
+
+Such a fixed link situation is described by creating a 'fixed-link'
+sub-node of the Ethernet MAC device node, with the following
+properties:
+
+* 'speed' (integer, mandatory), to indicate the link speed. Accepted
+  values are 10, 100 and 1000
+* 'full-duplex' (boolean, optional), to indicate that full duplex is
+  used. When absent, half duplex is assumed.
+* 'pause' (boolean, optional), to indicate that pause should be
+  enabled.
+* 'asym-pause' (boolean, optional), to indicate that asym_pause should
+  be enabled.
+
+Example:
+
+ethernet@0 {
+        ...
+        fixed-link {
+              speed = <1000>;
+              full-duplex;
+        };
+        ...
+};
diff --git a/drivers/of/of_mdio.c b/drivers/of/of_mdio.c
index 9a95831bd065..1def0bb5cb37 100644
--- a/drivers/of/of_mdio.c
+++ b/drivers/of/of_mdio.c
@@ -14,6 +14,7 @@
 #include <linux/netdevice.h>
 #include <linux/err.h>
 #include <linux/phy.h>
+#include <linux/phy_fixed.h>
 #include <linux/of.h>
 #include <linux/of_irq.h>
 #include <linux/of_mdio.h>
@@ -301,3 +302,69 @@ struct phy_device *of_phy_attach(struct net_device *dev,
         return phy_attach_direct(dev, phy, flags, iface) ? NULL : phy;
 }
 EXPORT_SYMBOL(of_phy_attach);
+
+#if defined(CONFIG_FIXED_PHY)
+/*
+ * of_phy_is_fixed_link() and of_phy_register_fixed_link() must
+ * support two DT bindings:
+ * - the old DT binding, where 'fixed-link' was a property with 5
+ *   cells encoding various informations about the fixed PHY
+ * - the new DT binding, where 'fixed-link' is a sub-node of the
+ *   Ethernet device.
+ */
+bool of_phy_is_fixed_link(struct device_node *np)
+{
+        struct device_node *dn;
+        int len;
+
+        /* New binding */
+        dn = of_get_child_by_name(np, "fixed-link");
+        if (dn) {
+                of_node_put(dn);
+                return true;
+        }
+
+        /* Old binding */
+        if (of_get_property(np, "fixed-link", &len) &&
+            len == (5 * sizeof(__be32)))
+                return true;
+
+        return false;
+}
+EXPORT_SYMBOL(of_phy_is_fixed_link);
+
+int of_phy_register_fixed_link(struct device_node *np)
+{
+        struct fixed_phy_status status = {};
+        struct device_node *fixed_link_node;
+        const __be32 *fixed_link_prop;
+        int len;
+
+        /* New binding */
+        fixed_link_node = of_get_child_by_name(np, "fixed-link");
+        if (fixed_link_node) {
+                status.link = 1;
+                status.duplex = of_property_read_bool(np, "full-duplex");
+                if (of_property_read_u32(fixed_link_node, "speed", &status.speed))
+                        return -EINVAL;
+                status.pause = of_property_read_bool(np, "pause");
+                status.asym_pause = of_property_read_bool(np, "asym-pause");
+                of_node_put(fixed_link_node);
+                return fixed_phy_register(PHY_POLL, &status, np);
+        }
+
+        /* Old binding */
+        fixed_link_prop = of_get_property(np, "fixed-link", &len);
+        if (fixed_link_prop && len == (5 * sizeof(__be32))) {
+                status.link = 1;
+                status.duplex = be32_to_cpu(fixed_link_prop[1]);
+                status.speed = be32_to_cpu(fixed_link_prop[2]);
+                status.pause = be32_to_cpu(fixed_link_prop[3]);
+                status.asym_pause = be32_to_cpu(fixed_link_prop[4]);
+                return fixed_phy_register(PHY_POLL, &status, np);
+        }
+
+        return -ENODEV;
+}
+EXPORT_SYMBOL(of_phy_register_fixed_link);
+#endif
diff --git a/include/linux/of_mdio.h b/include/linux/of_mdio.h
index 881a7c3571f4..0aa367e316cb 100644
--- a/include/linux/of_mdio.h
+++ b/include/linux/of_mdio.h
@@ -72,4 +72,19 @@ static inline struct mii_bus *of_mdio_find_bus(struct device_node *mdio_np)
 }
 #endif /* CONFIG_OF */
 
+#if defined(CONFIG_OF) && defined(CONFIG_FIXED_PHY)
+extern int of_phy_register_fixed_link(struct device_node *np);
+extern bool of_phy_is_fixed_link(struct device_node *np);
+#else
+static inline int of_phy_register_fixed_link(struct device_node *np)
+{
+        return -ENOSYS;
+}
+static inline bool of_phy_is_fixed_link(struct device_node *np)
+{
+        return false;
+}
+#endif
+
+
 #endif /* __LINUX_OF_MDIO_H */