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