libfdt: Add fdt functionality for more intuitive

index de82ed5..822ab18 100644
@@ -548,6 +548,37 @@ static inline void *fdt_getprop_w(void *fdt, int nodeoffset,
 }
 
 /**
+ * fdt_read - retrieve the value of a property by full path
+ * @fdt: pointer to the device tree blob
+ * @path: string containing the absolute path of the property
+ * @name: name of the property
+ * @lenp: pointer to an integer variable (will be overwritten) or NULL
+ *
+ * fdt_getprop() retrieves a pointer to the value of the property
+ * named 'name' of the node at offset nodeoffset (this will be a
+ * pointer to within the device blob itself, not a copy of the value).
+ * If lenp is non-NULL, the length of the property value is also
+ * returned, in the integer pointed to by lenp.
+ *
+ * returns:
+ *	pointer to the property's value
+ *		if lenp is non-NULL, *lenp contains the length of the property
+ *		value (>=0)
+ *	NULL, on error
+ *		if lenp is non-NULL, *lenp contains an error code (<0):
+ *		-FDT_ERR_NOTFOUND, node does not have named property
+ *		-FDT_ERR_BADOFFSET, nodeoffset did not point to FDT_BEGIN_NODE tag
+ *		-FDT_ERR_BADPATH,
+ *		-FDT_ERR_BADMAGIC,
+ *		-FDT_ERR_BADVERSION,
+ *		-FDT_ERR_BADSTATE,
+ *		-FDT_ERR_BADSTRUCTURE,
+ *		-FDT_ERR_TRUNCATED, standard meanings
+ */
+const void *fdt_read(const void *fdt, const char *path,
+			const char *name, int *lenp);
+
+/**
  * fdt_get_phandle - retrieve the phandle of a given node
  * @fdt: pointer to the device tree blob
  * @nodeoffset: structure block offset of the node

@@ -1066,6 +1097,38 @@ int fdt_set_name(void *fdt, int nodeoffset, const char *name);
  */
 int fdt_setprop(void *fdt, int nodeoffset, const char *name,
 		const void *val, int len);
+/**
+ * fdt_write - create or change a property with full path and create
+ *             all subnodes to the property if needed
+ * @fdt: pointer to the device tree blob
+ * @path: string containing the absolute path of the property
+ * @name: name of the property to change
+ * @val: pointer to data to set the property value to
+ * @len: length of the property value
+ *
+ * fdt_write() sets the value of the named property in the given
+ * node to the given value and length, creating the property if it
+ * does not already exist. Additionally it creates all parent nodes if
+ * not yet existing.
+ *
+ * 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_write(void *fdt, const char *path, const char *name,
+		const void *val, int len);
 
 /**
  * fdt_setprop_cell - set a property to a single cell value

@@ -1204,6 +1267,36 @@ int fdt_add_subnode_namelen(void *fdt, int parentoffset,
 int fdt_add_subnode(void *fdt, int parentoffset, const char *name);
 
 /**
+ * fdt_create_path - create subnode path with parents
+ * @fdt: pointer to the device tree blob
+ * @path: absolute path of subnodes to create
+ *
+ * fdt_create_path() creates absolute subnode path with all needed
+ * parents, if they don't exist.
+ *
+ * This function will insert data into the blob, and will therefore
+ * change the offsets of some existing nodes.
+ *
+ * returns:
+ *	structure block offset of the created nodeequested subnode (>=0), on success
+ *	-FDT_ERR_NOTFOUND, if the requested subnode does not exist
+ *	-FDT_ERR_BADOFFSET, if parentoffset did not point to an FDT_BEGIN_NODE tag
+ *	-FDT_ERR_EXISTS, if the node at parentoffset already has a subnode of
+ *		the given name
+ *	-FDT_ERR_NOSPACE, if there is insufficient free space in the
+ *		blob to contain the new node
+ *	-FDT_ERR_NOSPACE,
+ *	-FDT_ERR_BADPATH,
+ *	-FDT_ERR_BADLAYOUT,
+ *	-FDT_ERR_BADMAGIC,
+ *	-FDT_ERR_BADVERSION,
+ *	-FDT_ERR_BADSTATE,
+ *	-FDT_ERR_BADSTRUCTURE,
+ *	-FDT_ERR_TRUNCATED, standard meanings.
+ */
+int fdt_create_path(struct fdt_header *fdt, const char *path);
+
+/**
  * fdt_del_node - delete a node (subtree)
  * @fdt: pointer to the device tree blob
  * @nodeoffset: offset of the node to nop

index 1933010..9a08200 100644
@@ -324,6 +324,36 @@ const void *fdt_getprop(const void *fdt, int nodeoffset,
 	return fdt_getprop_namelen(fdt, nodeoffset, name, strlen(name), lenp);
 }
 
+const void *fdt_read(const void *fdt, const char *path,
+			const char *name, int *lenp)
+{
+	int nodeoffset;
+	int len;
+	const void *nodep ;
+
+	if (fdt_check_header(fdt) != 0) {
+		if (lenp)
+			*lenp = -FDT_ERR_BADSTRUCTURE;
+		return NULL;
+	}
+
+	nodeoffset = fdt_path_offset(fdt, path);
+
+	if (nodeoffset < 0) {
+		if (lenp)
+			*lenp = -FDT_ERR_BADPATH;
+		return NULL;
+	} else {
+		nodep = fdt_getprop(fdt, nodeoffset, name, &len);
+		if (len <= 0)
+			return NULL;
+		if (lenp)
+			*lenp = len;
+	}
+	return nodep;
+}
+
+
 uint32_t fdt_get_phandle(const void *fdt, int nodeoffset)
 {
 	const uint32_t *php;

109 lines not on this page · raw message

index 381133b..786a052 100644
@@ -55,6 +55,10 @@
 #define FDT_ALIGN(x, a)		(((x) + (a) - 1) & ~((a) - 1))
 #define FDT_TAGALIGN(x)		(FDT_ALIGN((x), FDT_TAGSIZE))
 
+#ifndef FDT_USE_MALLOC
+#define FDT_MAX_PATHLEN		2048
+#endif
+
 #define FDT_CHECK_HEADER(fdt) \
 	{ \
 		int err; \