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// SPDX-License-Identifier: GPL-2.0+
/*
* Retu watchdog driver
*
* Copyright (C) 2004, 2005 Nokia Corporation
*
* Based on code written by Amit Kucheria and Michael Buesch.
* Rewritten by Aaro Koskinen.
*/
#include <linux/devm-helpers.h>
#include <linux/slab.h>
#include <linux/errno.h>
#include <linux/device.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/mfd/retu.h>
#include <linux/watchdog.h>
#include <linux/platform_device.h>
/* Watchdog timer values in seconds */
#define RETU_WDT_MAX_TIMER 63
struct retu_wdt_dev {
struct retu_dev *rdev;
struct device *dev;
struct delayed_work ping_work;
};
/*
* Since Retu watchdog cannot be disabled in hardware, we must kick it
* with a timer until userspace watchdog software takes over. If
* CONFIG_WATCHDOG_NOWAYOUT is set, we never start the feeding.
*/
static void retu_wdt_ping_enable(struct retu_wdt_dev *wdev)
{
retu_write(wdev->rdev, RETU_REG_WATCHDOG, RETU_WDT_MAX_TIMER);
schedule_delayed_work(&wdev->ping_work,
round_jiffies_relative(RETU_WDT_MAX_TIMER * HZ / 2));
}
static void retu_wdt_ping_disable(struct retu_wdt_dev *wdev)
{
retu_write(wdev->rdev, RETU_REG_WATCHDOG, RETU_WDT_MAX_TIMER);
cancel_delayed_work_sync(&wdev->ping_work);
}
static void retu_wdt_ping_work(struct work_struct *work)
{
struct retu_wdt_dev *wdev = container_of(to_delayed_work(work),
struct retu_wdt_dev, ping_work);
retu_wdt_ping_enable(wdev);
}
static int retu_wdt_start(struct watchdog_device *wdog)
{
struct retu_wdt_dev *wdev = watchdog_get_drvdata(wdog);
retu_wdt_ping_disable(wdev);
return retu_write(wdev->rdev, RETU_REG_WATCHDOG, wdog->timeout);
}
static int retu_wdt_stop(struct watchdog_device *wdog)
{
struct retu_wdt_dev *wdev = watchdog_get_drvdata(wdog);
retu_wdt_ping_enable(wdev);
return 0;
}
static int retu_wdt_ping(struct watchdog_device *wdog)
{
struct retu_wdt_dev *wdev = watchdog_get_drvdata(wdog);
return retu_write(wdev->rdev, RETU_REG_WATCHDOG, wdog->timeout);
}
static int retu_wdt_set_timeout(struct watchdog_device *wdog,
unsigned int timeout)
{
struct retu_wdt_dev *wdev = watchdog_get_drvdata(wdog);
wdog->timeout = timeout;
return retu_write(wdev->rdev, RETU_REG_WATCHDOG, wdog->timeout);
}
static const struct watchdog_info retu_wdt_info = {
.options = WDIOF_SETTIMEOUT | WDIOF_MAGICCLOSE | WDIOF_KEEPALIVEPING,
.identity = "Retu watchdog",
};
static const struct watchdog_ops retu_wdt_ops = {
.owner = THIS_MODULE,
.start = retu_wdt_start,
.stop = retu_wdt_stop,
.ping = retu_wdt_ping,
.set_timeout = retu_wdt_set_timeout,
};
static int retu_wdt_probe(struct platform_device *pdev)
{
struct retu_dev *rdev = dev_get_drvdata(pdev->dev.parent);
bool nowayout = WATCHDOG_NOWAYOUT;
struct watchdog_device *retu_wdt;
struct retu_wdt_dev *wdev;
int ret;
retu_wdt = devm_kzalloc(&pdev->dev, sizeof(*retu_wdt), GFP_KERNEL);
if (!retu_wdt)
return -ENOMEM;
wdev = devm_kzalloc(&pdev->dev, sizeof(*wdev), GFP_KERNEL);
if (!wdev)
return -ENOMEM;
retu_wdt->info = &retu_wdt_info;
retu_wdt->ops = &retu_wdt_ops;
retu_wdt->timeout = RETU_WDT_MAX_TIMER;
retu_wdt->min_timeout = 0;
retu_wdt->max_timeout = RETU_WDT_MAX_TIMER;
retu_wdt->parent = &pdev->dev;
watchdog_set_drvdata(retu_wdt, wdev);
watchdog_set_nowayout(retu_wdt, nowayout);
wdev->rdev = rdev;
wdev->dev = &pdev->dev;
ret = devm_delayed_work_autocancel(&pdev->dev, &wdev->ping_work,
retu_wdt_ping_work);
if (ret)
return ret;
ret = devm_watchdog_register_device(&pdev->dev, retu_wdt);
if (ret < 0)
return ret;
if (nowayout)
retu_wdt_ping(retu_wdt);
else
retu_wdt_ping_enable(wdev);
return 0;
}
static struct platform_driver retu_wdt_driver = {
.probe = retu_wdt_probe,
.driver = {
.name = "retu-wdt",
},
};
module_platform_driver(retu_wdt_driver);
MODULE_ALIAS("platform:retu-wdt");
MODULE_DESCRIPTION("Retu watchdog");
MODULE_AUTHOR("Amit Kucheria");
MODULE_AUTHOR("Aaro Koskinen <aaro.koskinen@iki.fi>");
MODULE_LICENSE("GPL");
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