1 /*
2  * Copyright 2010 Michael Ellerman, IBM Corporation
3  *
4  * This program is free software; you can redistribute it and/or
5  * modify it under the terms of the GNU General Public License
6  * as published by the Free Software Foundation; either version
7  * 2 of the License, or (at your option) any later version.
8  */
9 
10 #include <linux/kernel.h>
11 #include <linux/of_platform.h>
12 
13 #include "wsp.h"
14 
15 /*
16  * Find chip-id by walking up device tree looking for ibm,wsp-chip-id property.
17  * Won't work for nodes that are not a descendant of a wsp node.
18  */
wsp_get_chip_id(struct device_node * dn)19 int wsp_get_chip_id(struct device_node *dn)
20 {
21 	const u32 *p;
22 	int rc;
23 
24 	/* Start looking at the specified node, not its parent */
25 	dn = of_node_get(dn);
26 	while (dn && !(p = of_get_property(dn, "ibm,wsp-chip-id", NULL)))
27 		dn = of_get_next_parent(dn);
28 
29 	if (!dn)
30 		return -1;
31 
32 	rc = *p;
33 	of_node_put(dn);
34 
35 	return rc;
36 }
37