phylib: give mdio buses a device tree presence

Introduce the mdio_bus class, and give each 'struct mii_bus' its own
'struct device', so that mii_bus objects are represented in the device
tree and can be found by querying the device tree.

Signed-off-by: Lennert Buytenhek <buytenh@marvell.com>
Acked-by: Andy Fleming <afleming@freescale.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

2 files changed, 79 insertions, 4 deletions

diff --git a/drivers/net/phy/mdio_bus.c b/drivers/net/phy/mdio_bus.c
index d206691f15d8..fb4c0965b152 100644
--- a/drivers/net/phy/mdio_bus.c
+++ b/drivers/net/phy/mdio_bus.c
@@ -43,11 +43,35 @@
  */
 struct mii_bus *mdiobus_alloc(void)
 {
-        return kzalloc(sizeof(struct mii_bus), GFP_KERNEL);
+        struct mii_bus *bus;
+
+        bus = kzalloc(sizeof(*bus), GFP_KERNEL);
+        if (bus != NULL)
+                bus->state = MDIOBUS_ALLOCATED;
+
+        return bus;
 }
 EXPORT_SYMBOL(mdiobus_alloc);
 
 /**
+ * mdiobus_release - mii_bus device release callback
+ *
+ * Description: called when the last reference to an mii_bus is
+ * dropped, to free the underlying memory.
+ */
+static void mdiobus_release(struct device *d)
+{
+        struct mii_bus *bus = to_mii_bus(d);
+        BUG_ON(bus->state != MDIOBUS_RELEASED);
+        kfree(bus);
+}
+
+static struct class mdio_bus_class = {
+        .name           = "mdio_bus",
+        .dev_release    = mdiobus_release,
+};
+
+/**
  * mdiobus_register - bring up all the PHYs on a given bus and attach them to bus
  * @bus: target mii_bus
  *
@@ -66,6 +90,22 @@ int mdiobus_register(struct mii_bus *bus)
                         NULL == bus->write)
                 return -EINVAL;
 
+        BUG_ON(bus->state != MDIOBUS_ALLOCATED &&
+               bus->state != MDIOBUS_UNREGISTERED);
+
+        bus->dev.parent = bus->parent;
+        bus->dev.class = &mdio_bus_class;
+        bus->dev.groups = NULL;
+        memcpy(bus->dev.bus_id, bus->id, MII_BUS_ID_SIZE);
+
+        err = device_register(&bus->dev);
+        if (err) {
+                printk(KERN_ERR "mii_bus %s failed to register\n", bus->id);
+                return -EINVAL;
+        }
+
+        bus->state = MDIOBUS_REGISTERED;
+
         mutex_init(&bus->mdio_lock);
 
         if (bus->reset)
@@ -92,6 +132,10 @@ void mdiobus_unregister(struct mii_bus *bus)
 {
         int i;
 
+        BUG_ON(bus->state != MDIOBUS_REGISTERED);
+        bus->state = MDIOBUS_UNREGISTERED;
+
+        device_unregister(&bus->dev);
         for (i = 0; i < PHY_MAX_ADDR; i++) {
                 if (bus->phy_map[i])
                         device_unregister(&bus->phy_map[i]->dev);
@@ -103,11 +147,24 @@ EXPORT_SYMBOL(mdiobus_unregister);
  * mdiobus_free - free a struct mii_bus
  * @bus: mii_bus to free
  *
- * This function frees the mii_bus.
+ * This function releases the reference to the underlying device
+ * object in the mii_bus.  If this is the last reference, the mii_bus
+ * will be freed.
  */
 void mdiobus_free(struct mii_bus *bus)
 {
-        kfree(bus);
+        /*
+         * For compatibility with error handling in drivers.
+         */
+        if (bus->state == MDIOBUS_ALLOCATED) {
+                kfree(bus);
+                return;
+        }
+
+        BUG_ON(bus->state != MDIOBUS_UNREGISTERED);
+        bus->state = MDIOBUS_RELEASED;
+
+        put_device(&bus->dev);
 }
 EXPORT_SYMBOL(mdiobus_free);
 
@@ -205,10 +262,20 @@ EXPORT_SYMBOL(mdio_bus_type);
 
 int __init mdio_bus_init(void)
 {
-        return bus_register(&mdio_bus_type);
+        int ret;
+
+        ret = class_register(&mdio_bus_class);
+        if (!ret) {
+                ret = bus_register(&mdio_bus_type);
+                if (ret)
+                        class_unregister(&mdio_bus_class);
+        }
+
+        return ret;
 }
 
 void mdio_bus_exit(void)
 {
+        class_unregister(&mdio_bus_class);
         bus_unregister(&mdio_bus_type);
 }
diff --git a/include/linux/phy.h b/include/linux/phy.h
index ca4a83c4c537..891f27f9137e 100644
--- a/include/linux/phy.h
+++ b/include/linux/phy.h
@@ -100,6 +100,13 @@ struct mii_bus {
         struct mutex mdio_lock;
 
         struct device *parent;
+        enum {
+                MDIOBUS_ALLOCATED = 1,
+                MDIOBUS_REGISTERED,
+                MDIOBUS_UNREGISTERED,
+                MDIOBUS_RELEASED,
+        } state;
+        struct device dev;
 
         /* list of all PHYs on bus */
         struct phy_device *phy_map[PHY_MAX_ADDR];
@@ -113,6 +120,7 @@ struct mii_bus {
          */
         int *irq;
 };
+#define to_mii_bus(d) container_of(d, struct mii_bus, dev)
 
 #define PHY_INTERRUPT_DISABLED  0x0
 #define PHY_INTERRUPT_ENABLED   0x80000000