1/*
2 * Copyright 2008 IBM Corp.
3 *
4 * Based on arch/powerpc/platforms/pasemi/idle.c:
5 * Copyright (C) 2006-2007 PA Semi, Inc
6 *
7 * Added by: Jerone Young <jyoung5@us.ibm.com>
8 *
9 * This program is free software; you can redistribute it and/or modify
10 * it under the terms of the GNU General Public License version 2 as
11 * published by the Free Software Foundation.
12 *
13 * This program is distributed in the hope that it will be useful,
14 * but WITHOUT ANY WARRANTY; without even the implied warranty of
15 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
16 * GNU General Public License for more details.
17 *
18 * You should have received a copy of the GNU General Public License
19 * along with this program; if not, write to the Free Software
20 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307 USA
21 *
22 */
23
24#include <linux/of.h>
25#include <linux/kernel.h>
26#include <asm/machdep.h>
27
28static int mode_spin;
29
30static void ppc44x_idle(void)
31{
32	unsigned long msr_save;
33
34	msr_save = mfmsr();
35	/* set wait state MSR */
36	mtmsr(msr_save|MSR_WE|MSR_EE|MSR_CE|MSR_DE);
37	isync();
38	/* return to initial state */
39	mtmsr(msr_save);
40	isync();
41}
42
43int __init ppc44x_idle_init(void)
44{
45	if (!mode_spin) {
46		/* If we are not setting spin mode
47                   then we set to wait mode */
48		ppc_md.power_save = &ppc44x_idle;
49	}
50
51	return 0;
52}
53
54arch_initcall(ppc44x_idle_init);
55
56static int __init idle_param(char *p)
57{
58
59	if (!strcmp("spin", p)) {
60		mode_spin = 1;
61		ppc_md.power_save = NULL;
62	}
63
64	return 0;
65}
66
67early_param("idle", idle_param);
68