pm.c

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/*
 * PXA250/210 Power Management Routines
 *
 * Original code for the SA11x0:
 * Copyright (c) 2001 Cliff Brake <[email protected]>
 *
 * 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 <mach/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(pxa_cpu_pm_fns->save_count * sizeof(unsigned long),
                 GFP_KERNEL);
    if (!sleep_save) {
        printk(KERN_ERR "failed to alloc memory for pm save\n");
        return -ENOMEM;
    }

    suspend_set_ops(&pxa_pm_ops);
    return 0;
}

device_initcall(pxa_pm_init);