// SPDX-License-Identifier: GPL-2.0-only
/*
 * Copyright (C) ST-Ericsson SA 2011-2013
 *
 * Author: Mathieu Poirier <mathieu.poirier@linaro.org> for ST-Ericsson
 * Author: Jonas Aaberg <jonas.aberg@stericsson.com> for ST-Ericsson
 */

#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt

#include <linux/module.h>
#include <linux/kernel.h>
#include <linux/moduleparam.h>
#include <linux/err.h>
#include <linux/uaccess.h>
#include <linux/watchdog.h>
#include <linux/platform_device.h>

#include <linux/mfd/dbx500-prcmu.h>

#define WATCHDOG_TIMEOUT 600 /* 10 minutes */

#define WATCHDOG_MIN    0
#define WATCHDOG_MAX28  268435  /* 28 bit resolution in ms == 268435.455 s */

static unsigned int timeout = WATCHDOG_TIMEOUT;
module_param(timeout, uint, 0);
MODULE_PARM_DESC(timeout,
        "Watchdog timeout in seconds. default="
                                __MODULE_STRING(WATCHDOG_TIMEOUT) ".");

static bool nowayout = WATCHDOG_NOWAYOUT;
module_param(nowayout, bool, 0);
MODULE_PARM_DESC(nowayout,
        "Watchdog cannot be stopped once started (default="
                                __MODULE_STRING(WATCHDOG_NOWAYOUT) ")");

static int db8500_wdt_start(struct watchdog_device *wdd)
{
        return prcmu_enable_a9wdog(PRCMU_WDOG_ALL);
}

static int db8500_wdt_stop(struct watchdog_device *wdd)
{
        return prcmu_disable_a9wdog(PRCMU_WDOG_ALL);
}

static int db8500_wdt_keepalive(struct watchdog_device *wdd)
{
        return prcmu_kick_a9wdog(PRCMU_WDOG_ALL);
}

static int db8500_wdt_set_timeout(struct watchdog_device *wdd,
                                 unsigned int timeout)
{
        db8500_wdt_stop(wdd);
        prcmu_load_a9wdog(PRCMU_WDOG_ALL, timeout * 1000);
        db8500_wdt_start(wdd);

        return 0;
}

static const struct watchdog_info db8500_wdt_info = {
        .options = WDIOF_SETTIMEOUT | WDIOF_KEEPALIVEPING | WDIOF_MAGICCLOSE,
        .identity = "DB8500 WDT",
        .firmware_version = 1,
};

static const struct watchdog_ops db8500_wdt_ops = {
        .owner = THIS_MODULE,
        .start = db8500_wdt_start,
        .stop  = db8500_wdt_stop,
        .ping  = db8500_wdt_keepalive,
        .set_timeout = db8500_wdt_set_timeout,
};

static struct watchdog_device db8500_wdt = {
        .info = &db8500_wdt_info,
        .ops = &db8500_wdt_ops,
        .min_timeout = WATCHDOG_MIN,
        .max_timeout = WATCHDOG_MAX28,
};

static int db8500_wdt_probe(struct platform_device *pdev)
{
        struct device *dev = &pdev->dev;
        int ret;

        timeout = 600; /* Default to 10 minutes */
        db8500_wdt.parent = dev;
        watchdog_set_nowayout(&db8500_wdt, nowayout);

        /* disable auto off on sleep */
        prcmu_config_a9wdog(PRCMU_WDOG_CPU1, false);

        /* set HW initial value */
        prcmu_load_a9wdog(PRCMU_WDOG_ALL, timeout * 1000);

        ret = devm_watchdog_register_device(dev, &db8500_wdt);
        if (ret)
                return ret;

        dev_info(dev, "initialized\n");

        return 0;
}

static int db8500_wdt_suspend(struct platform_device *pdev,
                             pm_message_t state)
{
        if (watchdog_active(&db8500_wdt)) {
                db8500_wdt_stop(&db8500_wdt);
                prcmu_config_a9wdog(PRCMU_WDOG_CPU1, true);

                prcmu_load_a9wdog(PRCMU_WDOG_ALL, timeout * 1000);
                db8500_wdt_start(&db8500_wdt);
        }
        return 0;
}

static int db8500_wdt_resume(struct platform_device *pdev)
{
        if (watchdog_active(&db8500_wdt)) {
                db8500_wdt_stop(&db8500_wdt);
                prcmu_config_a9wdog(PRCMU_WDOG_CPU1, false);

                prcmu_load_a9wdog(PRCMU_WDOG_ALL, timeout * 1000);
                db8500_wdt_start(&db8500_wdt);
        }
        return 0;
}

static struct platform_driver db8500_wdt_driver = {
        .probe          = db8500_wdt_probe,
        .suspend        = pm_ptr(db8500_wdt_suspend),
        .resume         = pm_ptr(db8500_wdt_resume),
        .driver         = {
                .name   = "db8500_wdt",
        },
};

module_platform_driver(db8500_wdt_driver);

MODULE_AUTHOR("Jonas Aaberg <jonas.aberg@stericsson.com>");
MODULE_DESCRIPTION("DB8500 Watchdog Driver");
MODULE_LICENSE("GPL");
MODULE_ALIAS("platform:db8500_wdt");