Adds a changeset helper for moving a subtree to a different place
in the running tree. This is useful in advances cases of dynamic
device tree construction.
Signed-off-by: Pantelis Antoniou <pantelis.antoniou@xxxxxxxxxxxx>
---
drivers/of/dynamic.c | 66 ++++++++++++++++++++++++++++++++++++++++++++++++++++
include/linux/of.h | 9 +++++++
2 files changed, 75 insertions(+)
diff --git a/drivers/of/dynamic.c b/drivers/of/dynamic.c
index 83cc801..b07fec2 100644
--- a/drivers/of/dynamic.c
+++ b/drivers/of/dynamic.c
@@ -1054,3 +1054,69 @@ int __of_changeset_add_update_property_string_list(
return ret;
}
EXPORT_SYMBOL_GPL(__of_changeset_add_update_property_string_list);
+
+static struct device_node *
+__of_changeset_node_move_one(struct of_changeset *ocs,
+ struct device_node *np, struct device_node *new_parent)
+{
+ struct device_node *np2;
+ const char *unitname;
+ int err;
+
+ err = of_changeset_detach_node(ocs, np);
+ if (err)
+ return ERR_PTR(err);
+
+ unitname = strrchr(np->full_name, '/');
+ if (!unitname)
+ unitname = np->full_name;
+
+ np2 = __of_node_dup(np, "%s/%s",
+ new_parent->full_name, unitname);
+ if (!np2)
+ return ERR_PTR(-ENOMEM);
+ np2->parent = new_parent;
+
+ err = of_changeset_attach_node(ocs, np2);
+ if (err)
+ return ERR_PTR(err);
+
+ return np2;
+}
+
+/**
+ * of_changeset_node_move_to - Moves a subtree to a new place in
+ * the tree
+ *
+ * @ocs: changeset pointer
+ * @np: device node pointer to be moved
+ * @to: device node of the new parent
+ *
+ * Moves a subtree to a new place in the tree.
+ * Note that a move is a safe operation because the phandles
+ * remain valid.
+ *
+ * Returns zero on success, a negative error value otherwise.
+ */
+int of_changeset_node_move(struct of_changeset *ocs,
+ struct device_node *np, struct device_node *new_parent)
+{
+ struct device_node *npc, *nppc;
+
+ /* move the root first */
+ nppc = __of_changeset_node_move_one(ocs, np, new_parent);
+ if (IS_ERR(nppc))
+ return PTR_ERR(nppc);
+
+ /* move the subtrees next */
+ for_each_child_of_node(np, npc) {
+ nppc = __of_changeset_node_move_one(ocs, npc, nppc);
+ if (IS_ERR(nppc)) {
+ of_node_put(npc);
+ return PTR_ERR(nppc);
+ }
+ }
+
+ return 0;
+}
+EXPORT_SYMBOL_GPL(of_changeset_node_move);
diff --git a/include/linux/of.h b/include/linux/of.h
index 9df3b71..97ac5c8 100644
--- a/include/linux/of.h
+++ b/include/linux/of.h
@@ -1056,6 +1056,9 @@ int __of_changeset_add_update_property_string_list(
struct of_changeset *ocs, struct device_node *np,
const char *name, const char **strs, int count, bool update);
+int of_changeset_node_move(struct of_changeset *ocs,
+ struct device_node *np, struct device_node *new_parent);
+
#else /* CONFIG_OF_DYNAMIC */
static inline int of_reconfig_notifier_register(struct notifier_block *nb)
{
@@ -1118,6 +1121,12 @@ static inline int __of_changeset_add_update_property_string_list(
return -EINVAL;
}
+static inline int of_changeset_node_move(struct of_changeset *ocs,
+ struct device_node *np, struct device_node *new_parent)
+{
+ return -EINVAL;
+}
+
#endif /* CONFIG_OF_DYNAMIC */
/**
--
1.7.12
--
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