idle.c

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/*
 * Copyright 2008 IBM Corp. 
 *
 * Based on arch/powerpc/platforms/pasemi/idle.c: 
 * Copyright (C) 2006-2007 PA Semi, Inc
 *
 * Added by: Jerone Young <[email protected]>
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License version 2 as
 * published by the Free Software Foundation.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307 USA
 *
 */

#include <linux/of.h>
#include <linux/kernel.h>
#include <asm/machdep.h>

static int mode_spin;

static void ppc44x_idle(void)
{
    unsigned long msr_save;

    msr_save = mfmsr();
    /* set wait state MSR */
    mtmsr(msr_save|MSR_WE|MSR_EE|MSR_CE|MSR_DE);
    isync();
    /* return to initial state */
    mtmsr(msr_save);
    isync();
}

int __init ppc44x_idle_init(void)
{
    if (!mode_spin) {
        /* If we are not setting spin mode 
                   then we set to wait mode */
        ppc_md.power_save = &ppc44x_idle;
    }

    return 0;
}

arch_initcall(ppc44x_idle_init);

static int __init idle_param(char *p)
{ 

    if (!strcmp("spin", p)) {
        mode_spin = 1;
        ppc_md.power_save = NULL;
    }

    return 0;
}

early_param("idle", idle_param);