1/*
  2 * Copyright (C) 2006-2007 PA Semi, Inc
  3 *
  4 * Maintained by: Olof Johansson <olof@lixom.net>
  5 *
  6 * This program is free software; you can redistribute it and/or modify
  7 * it under the terms of the GNU General Public License version 2 as
  8 * published by the Free Software Foundation.
  9 *
 10 * This program is distributed in the hope that it will be useful,
 11 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 12 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 13 * GNU General Public License for more details.
 14 *
 15 * You should have received a copy of the GNU General Public License
 16 * along with this program; if not, write to the Free Software
 17 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307 USA
 18 *
 19 */
 20
 21#undef DEBUG
 22
 23#include <linux/kernel.h>
 24#include <linux/string.h>
 25#include <linux/irq.h>
 26
 27#include <asm/machdep.h>
 28#include <asm/reg.h>
 29#include <asm/smp.h>
 30
 31#include "pasemi.h"
 32
 33struct sleep_mode {
 34	char *name;
 35	void (*entry)(void);
 36};
 37
 38static struct sleep_mode modes[] = {
 39	{ .name = "spin", .entry = &idle_spin },
 40	{ .name = "doze", .entry = &idle_doze },
 41};
 42
 43static int current_mode = 0;
 44
 45static int pasemi_system_reset_exception(struct pt_regs *regs)
 46{
 47	/* If we were woken up from power savings, we need to return
 48	 * to the calling function, since nip is not saved across
 49	 * all modes.
 50	 */
 51
 52	if (regs->msr & SRR1_WAKEMASK)
 53		regs->nip = regs->link;
 54
 55	switch (regs->msr & SRR1_WAKEMASK) {
 56	case SRR1_WAKEEE:
 57		do_IRQ(regs);
 58		break;
 59	case SRR1_WAKEDEC:
 60		timer_interrupt(regs);
 61		break;
 62	default:
 63		/* do system reset */
 64		return 0;
 65	}
 66
 67	/* Set higher astate since we come out of power savings at 0 */
 68	restore_astate(hard_smp_processor_id());
 69
 70	/* everything handled */
 71	regs->msr |= MSR_RI;
 72	return 1;
 73}
 74
 75static int __init pasemi_idle_init(void)
 76{
 77#ifndef CONFIG_PPC_PASEMI_CPUFREQ
 78	printk(KERN_WARNING "No cpufreq driver, powersavings modes disabled\n");
 79	current_mode = 0;
 80#endif
 81
 82	ppc_md.system_reset_exception = pasemi_system_reset_exception;
 83	ppc_md.power_save = modes[current_mode].entry;
 84	printk(KERN_INFO "Using PA6T idle loop (%s)\n", modes[current_mode].name);
 85
 86	return 0;
 87}
 88machine_late_initcall(pasemi, pasemi_idle_init);
 89
 90static int __init idle_param(char *p)
 91{
 92	int i;
 93	for (i = 0; i < ARRAY_SIZE(modes); i++) {
 94		if (!strcmp(modes[i].name, p)) {
 95			current_mode = i;
 96			break;
 97		}
 98	}
 99	return 0;
100}
101
102early_param("idle", idle_param);