3 files changed, 106 insertions, 3 deletions

diff --git a/lib/libfdt/fdt_rw.c b/lib/libfdt/fdt_rw.c
index 80a3212141..3dc775261f 100644
--- a/lib/libfdt/fdt_rw.c
+++ b/lib/libfdt/fdt_rw.c
@@ -228,8 +228,8 @@ int fdt_set_name(void *fdt, int nodeoffset, const char *name)
 	return 0;
 }
 
-int fdt_setprop(void *fdt, int nodeoffset, const char *name,
-		const void *val, int len)
+int fdt_setprop_placeholder(void *fdt, int nodeoffset, const char *name,
+			    int len, void **prop_data)
 {
 	struct fdt_property *prop;
 	int err;
@@ -242,8 +242,22 @@ int fdt_setprop(void *fdt, int nodeoffset, const char *name,
 	if (err)
 		return err;
 
+	*prop_data = prop->data;
+	return 0;
+}
+
+int fdt_setprop(void *fdt, int nodeoffset, const char *name,
+		const void *val, int len)
+{
+	void *prop_data;
+	int err;
+
+	err = fdt_setprop_placeholder(fdt, nodeoffset, name, len, &prop_data);
+	if (err)
+		return err;
+
 	if (len)
-		memcpy(prop->data, val, len);
+		memcpy(prop_data, val, len);
 	return 0;
 }
 
diff --git a/lib/libfdt/libfdt.h b/lib/libfdt/libfdt.h
index f3f9cad184..6af94cb3f7 100644
--- a/lib/libfdt/libfdt.h
+++ b/lib/libfdt/libfdt.h
@@ -1405,6 +1405,37 @@ int fdt_setprop(void *fdt, int nodeoffset, const char *name,
 		const void *val, int len);
 
 /**
+ * fdt_setprop _placeholder - allocate space for a property
+ * @fdt: pointer to the device tree blob
+ * @nodeoffset: offset of the node whose property to change
+ * @name: name of the property to change
+ * @len: length of the property value
+ * @prop_data: return pointer to property data
+ *
+ * fdt_setprop_placeholer() allocates the named property in the given node.
+ * If the property exists it is resized. In either case a pointer to the
+ * property data is returned.
+ *
+ * This function may insert or delete data from the blob, and will
+ * therefore change the offsets of some existing nodes.
+ *
+ * returns:
+ *	0, on success
+ *	-FDT_ERR_NOSPACE, there is insufficient free space in the blob to
+ *		contain the new property value
+ *	-FDT_ERR_BADOFFSET, nodeoffset did not point to FDT_BEGIN_NODE tag
+ *	-FDT_ERR_BADLAYOUT,
+ *	-FDT_ERR_BADMAGIC,
+ *	-FDT_ERR_BADVERSION,
+ *	-FDT_ERR_BADSTATE,
+ *	-FDT_ERR_BADSTRUCTURE,
+ *	-FDT_ERR_BADLAYOUT,
+ *	-FDT_ERR_TRUNCATED, standard meanings
+ */
+int fdt_setprop_placeholder(void *fdt, int nodeoffset, const char *name,
+			    int len, void **prop_data);
+
+/**
  * fdt_setprop_u32 - set a property to a 32-bit integer
  * @fdt: pointer to the device tree blob
  * @nodeoffset: offset of the node whose property to change
diff --git a/lib/libfdt/pylibfdt/libfdt.i b/lib/libfdt/pylibfdt/libfdt.i
index 146f4b942a..5b1a8cf4d4 100644
--- a/lib/libfdt/pylibfdt/libfdt.i
+++ b/lib/libfdt/pylibfdt/libfdt.i
@@ -130,6 +130,23 @@ class Fdt:
         self._fdt = bytearray(data)
         check_err(fdt_check_header(self._fdt));
 
+    def subnode_offset(self, parentoffset, name, quiet=()):
+        """Get the offset of a named subnode
+
+        Args:
+            parentoffset: Offset of the parent node to check
+            name: Name of the required subnode, e.g. 'subnode@1'
+            quiet: Errors to ignore (empty to raise on all errors)
+
+        Returns:
+            The node offset of the found node, if any
+
+        Raises
+            FdtException if there is no node with that name, or other error
+        """
+        return check_err(fdt_subnode_offset(self._fdt, parentoffset, name),
+                         quiet)
+
     def path_offset(self, path, quiet=()):
         """Get the offset for a given path
 
@@ -304,6 +321,47 @@ class Fdt:
             return pdata
         return bytearray(pdata[0])
 
+    def get_phandle(self, nodeoffset):
+        """Get the phandle of a node
+
+        Args:
+            nodeoffset: Node offset to check
+
+        Returns:
+            phandle of node, or 0 if the node has no phandle or another error
+            occurs
+        """
+        return fdt_get_phandle(self._fdt, nodeoffset)
+
+    def parent_offset(self, nodeoffset, quiet=()):
+        """Get the offset of a node's parent
+
+        Args:
+            nodeoffset: Node offset to check
+            quiet: Errors to ignore (empty to raise on all errors)
+
+        Returns:
+            The offset of the parent node, if any
+
+        Raises:
+            FdtException if no parent found or other error occurs
+        """
+        return check_err(fdt_parent_offset(self._fdt, nodeoffset), quiet)
+
+    def node_offset_by_phandle(self, phandle, quiet=()):
+        """Get the offset of a node with the given phandle
+
+        Args:
+            phandle: Phandle to search for
+            quiet: Errors to ignore (empty to raise on all errors)
+
+        Returns:
+            The offset of node with that phandle, if any
+
+        Raises:
+            FdtException if no node found or other error occurs
+        """
+        return check_err(fdt_node_offset_by_phandle(self._fdt, phandle), quiet)
 
 class Property:
     """Holds a device tree property name and value.