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" using a special PHY node.
This patch adds:
* A documentation for the fixed PHY Device Tree binding.
* An of_phy_is_fixed_link() function that an Ethernet driver can call
on its PHY phandle to find out whether it's a fixed link PHY or
not. It should typically be used to know if
of_phy_register_fixed_link() should be called.
* An of_phy_register_fixed_link() function that instantiates the
fixed PHY into the PHY subsystem, so that when the driver calls
of_phy_connect(), the PHY device associated to the OF node will be
found.
These two additional functions also support the old fixed-link Device
Tree binding used on PowerPC platforms, so that ultimately, the
network device drivers for those platforms could be converted to use
of_phy_is_fixed_link() and of_phy_register_fixed_link() instead of
of_phy_connect_fixed_link(), while keeping compatibility with their
respective Device Tree bindings.
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@xxxxxxxxxxxxxxxxxx>
---
.../devicetree/bindings/net/fixed-link.txt | 31 ++++++++++
drivers/of/of_mdio.c | 67 ++++++++++++++++++++++
include/linux/of_mdio.h | 15 +++++
3 files changed, 113 insertions(+)
create mode 100644 Documentation/devicetree/bindings/net/fixed-link.txt
diff --git a/Documentation/devicetree/bindings/net/fixed-link.txt b/Documentation/devicetree/bindings/net/fixed-link.txt
new file mode 100644
index 0000000..377f775
--- /dev/null
+++ b/Documentation/devicetree/bindings/net/fixed-link.txt
@@ -0,0 +1,31 @@
+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 9a95831..1def0bb 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 6fe8464..77a6e32 100644
--- a/include/linux/of_mdio.h
+++ b/include/linux/of_mdio.h
@@ -67,4 +67,19 @@ 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 */
--
1.9.3
--
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