fdt: introduce fdt_create_phandle()

The ePAPR specification says that phandle properties should be called
"phandle", and not "linux,phandle".  To facilitate the migration from
"linux,phandle" to "phandle", introduce function fdt_create_phandle(),
which creates a phandle in a given node.  For now, we create both the
"phandle" and "linux,phandle" properties.  A later version of this
function will remove support for "linux,phandle".

Signed-off-by: Timur Tabi <timur@freescale.com>

common/fdt_support.c

@@ -1195,6 +1195,46 @@ int fdt_alloc_phandle(void *blob)
 	return phandle + 1;
 }
 
+/*
+ * fdt_create_phandle: Create a phandle property for the given node
+ *
+ * @fdt: ptr to device tree
+ * @nodeoffset: node to update
+ * @phandle: phandle value to set (must be unique)
+*/
+int fdt_create_phandle(void *fdt, int nodeoffset, uint32_t phandle)
+{
+	int ret;
+
+#ifdef DEBUG
+	int off = fdt_node_offset_by_phandle(fdt, phandle);
+
+	if ((off >= 0) && (off != nodeoffset)) {
+		char buf[64];
+
+		fdt_get_path(fdt, nodeoffset, buf, sizeof(buf));
+		printf("Trying to update node %s with phandle %u ",
+		       buf, phandle);
+
+		fdt_get_path(fdt, off, buf, sizeof(buf));
+		printf("that already exists in node %s.\n", buf);
+		return -FDT_ERR_BADPHANDLE;
+	}
+#endif
+
+	ret = fdt_setprop_cell(fdt, nodeoffset, "phandle", phandle);
+	if (ret < 0)
+		return ret;
+
+	/*
+	 * For now, also set the deprecated "linux,phandle" property, so that we
+	 * don't break older kernels.
+	 */
+	ret = fdt_setprop_cell(fdt, nodeoffset, "linux,phandle", phandle);
+
+	return ret;
+}
+
 #if defined(CONFIG_VIDEO)
 int fdt_add_edid(void *blob, const char *compat, unsigned char *edid_buf)
 {

include/fdt_support.h

@@ -89,6 +89,7 @@ u64 fdt_translate_address(void *blob, int node_offset, const u32 *in_addr);
 int fdt_node_offset_by_compat_reg(void *blob, const char *compat,
 					phys_addr_t compat_off);
 int fdt_alloc_phandle(void *blob);
+int fdt_create_phandle(void *fdt, int nodeoffset, uint32_t phandle);
 int fdt_add_edid(void *blob, const char *compat, unsigned char *buf);
 
 int fdt_verify_alias_address(void *fdt, int anode, const char *alias,