of: merge of_attach_node() & of_detach_node()

[deliverable/linux.git] / drivers / of / base.c

diff --git a/drivers/of/base.c b/drivers/of/base.c
index cf89ee6253f3ef9799efaeb630a3ae7a43a8f5cd..2ce58be314afd5d6a000ca6df0f9058ba0c0b80b 100644 (file)
--- a/drivers/of/base.c
+++ b/drivers/of/base.c
@@ -870,3 +870,74 @@ int prom_update_property(struct device_node *np,
 
        return 0;
 }
+
+#if defined(CONFIG_OF_DYNAMIC)
+/*
+ * Support for dynamic device trees.
+ *
+ * On some platforms, the device tree can be manipulated at runtime.
+ * The routines in this section support adding, removing and changing
+ * device tree nodes.
+ */
+
+/**
+ * of_attach_node - Plug a device node into the tree and global list.
+ */
+void of_attach_node(struct device_node *np)
+{
+       unsigned long flags;
+
+       write_lock_irqsave(&devtree_lock, flags);
+       np->sibling = np->parent->child;
+       np->allnext = allnodes;
+       np->parent->child = np;
+       allnodes = np;
+       write_unlock_irqrestore(&devtree_lock, flags);
+}
+
+/**
+ * of_detach_node - "Unplug" a node from the device tree.
+ *
+ * The caller must hold a reference to the node.  The memory associated with
+ * the node is not freed until its refcount goes to zero.
+ */
+void of_detach_node(struct device_node *np)
+{
+       struct device_node *parent;
+       unsigned long flags;
+
+       write_lock_irqsave(&devtree_lock, flags);
+
+       parent = np->parent;
+       if (!parent)
+               goto out_unlock;
+
+       if (allnodes == np)
+               allnodes = np->allnext;
+       else {
+               struct device_node *prev;
+               for (prev = allnodes;
+                    prev->allnext != np;
+                    prev = prev->allnext)
+                       ;
+               prev->allnext = np->allnext;
+       }
+
+       if (parent->child == np)
+               parent->child = np->sibling;
+       else {
+               struct device_node *prevsib;
+               for (prevsib = np->parent->child;
+                    prevsib->sibling != np;
+                    prevsib = prevsib->sibling)
+                       ;
+               prevsib->sibling = np->sibling;
+       }
+
+       of_node_set_flag(np, OF_DETACHED);
+
+out_unlock:
+       write_unlock_irqrestore(&devtree_lock, flags);
+}
+#endif /* defined(CONFIG_OF_DYNAMIC) */
+