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