// SPDX-License-Identifier: GPL-2.0-or-later
/*
 * Suspend/resume support
 *
 * Copyright 2009  MontaVista Software, Inc.
 *
 * Author: Anton Vorontsov <avorontsov@ru.mvista.com>
 */

#include <linux/init.h>
#include <linux/types.h>
#include <linux/errno.h>
#include <linux/export.h>
#include <linux/suspend.h>
#include <linux/delay.h>
#include <linux/mod_devicetable.h>
#include <linux/of_address.h>
#include <linux/platform_device.h>

struct pmc_regs {
        __be32 devdisr;
        __be32 devdisr2;
        __be32 :32;
        __be32 :32;
        __be32 pmcsr;
#define PMCSR_SLP       (1 << 17)
};

static struct device *pmc_dev;
static struct pmc_regs __iomem *pmc_regs;

static int pmc_suspend_enter(suspend_state_t state)
{
        int ret;

        setbits32(&pmc_regs->pmcsr, PMCSR_SLP);
        /* At this point, the CPU is asleep. */

        /* Upon resume, wait for SLP bit to be clear. */
        ret = spin_event_timeout((in_be32(&pmc_regs->pmcsr) & PMCSR_SLP) == 0,
                                 10000, 10) ? 0 : -ETIMEDOUT;
        if (ret)
                dev_err(pmc_dev, "tired waiting for SLP bit to clear\n");
        return ret;
}

static int pmc_suspend_valid(suspend_state_t state)
{
        if (state != PM_SUSPEND_STANDBY)
                return 0;
        return 1;
}

static const struct platform_suspend_ops pmc_suspend_ops = {
        .valid = pmc_suspend_valid,
        .enter = pmc_suspend_enter,
};

static int pmc_probe(struct platform_device *ofdev)
{
        pmc_regs = of_iomap(ofdev->dev.of_node, 0);
        if (!pmc_regs)
                return -ENOMEM;

        pmc_dev = &ofdev->dev;
        suspend_set_ops(&pmc_suspend_ops);
        return 0;
}

static const struct of_device_id pmc_ids[] = {
        { .compatible = "fsl,mpc8548-pmc", },
        { .compatible = "fsl,mpc8641d-pmc", },
        { },
};

static struct platform_driver pmc_driver = {
        .driver = {
                .name = "fsl-pmc",
                .of_match_table = pmc_ids,
        },
        .probe = pmc_probe,
};

builtin_platform_driver(pmc_driver);