openfirmware: Add OF phylib support code

Add support for parsing the device tree for PHY devices on an MDIO bus.
Currently many of the PowerPC ethernet drivers are open coding a solution
for reading data out of the device tree to find the correct PHY device.
This patch implements a set of common routines to:

a) let MDIO bus drivers register phy_devices described in the tree, and
b) let MAC drivers find the correct phy_device via the tree.

Signed-off-by: Grant Likely <grant.likely@secretlab.ca>
Acked-by: Andy Fleming <afleming@freescale.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 139 insertions, 0 deletions

diff --git a/drivers/of/of_mdio.c b/drivers/of/of_mdio.c
new file mode 100644
index 000000000000..aee967d7f760
--- /dev/null
+++ b/drivers/of/of_mdio.c
@@ -0,0 +1,139 @@
+/*
+ * OF helpers for the MDIO (Ethernet PHY) API
+ *
+ * Copyright (c) 2009 Secret Lab Technologies, Ltd.
+ *
+ * This file is released under the GPLv2
+ *
+ * This file provides helper functions for extracting PHY device information
+ * out of the OpenFirmware device tree and using it to populate an mii_bus.
+ */
+
+#include <linux/phy.h>
+#include <linux/of.h>
+#include <linux/of_mdio.h>
+#include <linux/module.h>
+
+MODULE_AUTHOR("Grant Likely <grant.likely@secretlab.ca>");
+MODULE_LICENSE("GPL");
+
+/**
+ * of_mdiobus_register - Register mii_bus and create PHYs from the device tree
+ * @mdio: pointer to mii_bus structure
+ * @np: pointer to device_node of MDIO bus.
+ *
+ * This function registers the mii_bus structure and registers a phy_device
+ * for each child node of @np.
+ */
+int of_mdiobus_register(struct mii_bus *mdio, struct device_node *np)
+{
+        struct phy_device *phy;
+        struct device_node *child;
+        int rc, i;
+
+        /* Mask out all PHYs from auto probing.  Instead the PHYs listed in
+         * the device tree are populated after the bus has been registered */
+        mdio->phy_mask = ~0;
+
+        /* Clear all the IRQ properties */
+        if (mdio->irq)
+                for (i=0; i<PHY_MAX_ADDR; i++)
+                        mdio->irq[i] = PHY_POLL;
+
+        /* Register the MDIO bus */
+        rc = mdiobus_register(mdio);
+        if (rc)
+                return rc;
+
+        /* Loop over the child nodes and register a phy_device for each one */
+        for_each_child_of_node(np, child) {
+                const u32 *addr;
+                int len;
+
+                /* A PHY must have a reg property in the range [0-31] */
+                addr = of_get_property(child, "reg", &len);
+                if (!addr || len < sizeof(*addr) || *addr >= 32 || *addr < 0) {
+                        dev_err(&mdio->dev, "%s has invalid PHY address\n",
+                                child->full_name);
+                        continue;
+                }
+
+                if (mdio->irq) {
+                        mdio->irq[*addr] = irq_of_parse_and_map(child, 0);
+                        if (!mdio->irq[*addr])
+                                mdio->irq[*addr] = PHY_POLL;
+                }
+
+                phy = get_phy_device(mdio, *addr);
+                if (!phy) {
+                        dev_err(&mdio->dev, "error probing PHY at address %i\n",
+                                *addr);
+                        continue;
+                }
+                phy_scan_fixups(phy);
+
+                /* Associate the OF node with the device structure so it
+                 * can be looked up later */
+                of_node_get(child);
+                dev_archdata_set_node(&phy->dev.archdata, child);
+
+                /* All data is now stored in the phy struct; register it */
+                rc = phy_device_register(phy);
+                if (rc) {
+                        phy_device_free(phy);
+                        of_node_put(child);
+                        continue;
+                }
+
+                dev_dbg(&mdio->dev, "registered phy %s at address %i\n",
+                        child->name, *addr);
+        }
+
+        return 0;
+}
+EXPORT_SYMBOL(of_mdiobus_register);
+
+/**
+ * of_phy_find_device - Give a PHY node, find the phy_device
+ * @phy_np: Pointer to the phy's device tree node
+ *
+ * Returns a pointer to the phy_device.
+ */
+struct phy_device *of_phy_find_device(struct device_node *phy_np)
+{
+        struct device *d;
+        int match(struct device *dev, void *phy_np)
+        {
+                return dev_archdata_get_node(&dev->archdata) == phy_np;
+        }
+
+        if (!phy_np)
+                return NULL;
+
+        d = bus_find_device(&mdio_bus_type, NULL, phy_np, match);
+        return d ? to_phy_device(d) : NULL;
+}
+EXPORT_SYMBOL(of_phy_find_device);
+
+/**
+ * of_phy_connect - Connect to the phy described in the device tree
+ * @dev: pointer to net_device claiming the phy
+ * @phy_np: Pointer to device tree node for the PHY
+ * @hndlr: Link state callback for the network device
+ * @iface: PHY data interface type
+ *
+ * Returns a pointer to the phy_device if successfull.  NULL otherwise
+ */
+struct phy_device *of_phy_connect(struct net_device *dev,
+                                  struct device_node *phy_np,
+                                  void (*hndlr)(struct net_device *), u32 flags,
+                                  phy_interface_t iface)
+{
+        struct phy_device *phy = of_phy_find_device(phy_np);
+
+        if (!phy)
+                return NULL;
+
+        return phy_connect_direct(dev, phy, hndlr, flags, iface) ? NULL : phy;
+}
+EXPORT_SYMBOL(of_phy_connect);