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path: root/drivers/of/base.c
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-rw-r--r--drivers/of/base.c71
1 files changed, 71 insertions, 0 deletions
diff --git a/drivers/of/base.c b/drivers/of/base.c
index cf89ee6253f..2ce58be314a 100644
--- 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) */
+