linux/arch/arm/mach-pxa/pm.c

/*
 * PXA250/210 Power Management Routines
 *
 * Original code for the SA11x0:
 * Copyright (c) 2001 Cliff Brake <cbrake@accelent.com>
 *
 * Modified for the PXA250 by Nicolas Pitre:
 * Copyright (c) 2002 Monta Vista Software, Inc.
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public License.
 */
#include <linux/init.h>
#include <linux/module.h>
#include <linux/suspend.h>
#include <linux/errno.h>
#include <linux/slab.h>

#include "pm.h"

struct pxa_cpu_pm_fns *pxa_cpu_pm_fns;
static unsigned long *sleep_save;

int pxa_pm_enter(suspend_state_t state)
{
	unsigned long sleep_save_checksum = 0, checksum = 0;
	int i;

#ifdef CONFIG_IWMMXT
	/* force any iWMMXt context to ram **/
	if (elf_hwcap & HWCAP_IWMMXT)
		iwmmxt_task_disable(NULL);
#endif

	/* skip registers saving for standby */
	if (state != PM_SUSPEND_STANDBY && pxa_cpu_pm_fns->save) {
		pxa_cpu_pm_fns->save(sleep_save);
		/* before sleeping, calculate and save a checksum */
		for (i = 0; i < pxa_cpu_pm_fns->save_count - 1; i++)
			sleep_save_checksum += sleep_save[i];
	}

	/* *** go zzz *** */
	pxa_cpu_pm_fns->enter(state);

	if (state != PM_SUSPEND_STANDBY && pxa_cpu_pm_fns->restore) {
		/* after sleeping, validate the checksum */
		for (i = 0; i < pxa_cpu_pm_fns->save_count - 1; i++)
			checksum += sleep_save[i];

		/* if invalid, display message and wait for a hardware reset */
		if (checksum != sleep_save_checksum) {

			lubbock_set_hexled(0xbadbadc5);

			while (1)
				pxa_cpu_pm_fns->enter(state);
		}
		pxa_cpu_pm_fns->restore(sleep_save);
	}

	pr_debug("*** made it back from resume\n");

	return 0;
}

EXPORT_SYMBOL_GPL(pxa_pm_enter);

static int pxa_pm_valid(suspend_state_t state)
{
	if (pxa_cpu_pm_fns)
		return pxa_cpu_pm_fns->valid(state);

	return -EINVAL;
}

int pxa_pm_prepare(void)
{
	int ret = 0;

	if (pxa_cpu_pm_fns && pxa_cpu_pm_fns->prepare)
		ret = pxa_cpu_pm_fns->prepare();

	return ret;
}

void pxa_pm_finish(void)
{
	if (pxa_cpu_pm_fns && pxa_cpu_pm_fns->finish)
		pxa_cpu_pm_fns->finish();
}

static const struct platform_suspend_ops pxa_pm_ops = {
	.valid		= pxa_pm_valid,
	.enter		= pxa_pm_enter,
	.prepare	= pxa_pm_prepare,
	.finish		= pxa_pm_finish,
};

static int __init pxa_pm_init(void)
{
	if (!pxa_cpu_pm_fns) {
		printk(KERN_ERR "no valid pxa_cpu_pm_fns defined\n");
		return -EINVAL;
	}

	sleep_save = kmalloc_array(pxa_cpu_pm_fns->save_count,
				   sizeof(*sleep_save),
				   GFP_KERNEL);
	if (!sleep_save)
		return -ENOMEM;

	suspend_set_ops(&pxa_pm_ops);
	return 0;
}

device_initcall(pxa_pm_init);