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1// SPDX-License-Identifier: GPL-2.0+2/*3 * Retu watchdog driver4 *5 * Copyright (C) 2004, 2005 Nokia Corporation6 *7 * Based on code written by Amit Kucheria and Michael Buesch.8 * Rewritten by Aaro Koskinen.9 */10 11#include <linux/devm-helpers.h>12#include <linux/slab.h>13#include <linux/errno.h>14#include <linux/device.h>15#include <linux/kernel.h>16#include <linux/module.h>17#include <linux/mfd/retu.h>18#include <linux/watchdog.h>19#include <linux/platform_device.h>20 21/* Watchdog timer values in seconds */22#define RETU_WDT_MAX_TIMER 6323 24struct retu_wdt_dev {25 struct retu_dev *rdev;26 struct device *dev;27 struct delayed_work ping_work;28};29 30/*31 * Since Retu watchdog cannot be disabled in hardware, we must kick it32 * with a timer until userspace watchdog software takes over. If33 * CONFIG_WATCHDOG_NOWAYOUT is set, we never start the feeding.34 */35static void retu_wdt_ping_enable(struct retu_wdt_dev *wdev)36{37 retu_write(wdev->rdev, RETU_REG_WATCHDOG, RETU_WDT_MAX_TIMER);38 schedule_delayed_work(&wdev->ping_work,39 round_jiffies_relative(RETU_WDT_MAX_TIMER * HZ / 2));40}41 42static void retu_wdt_ping_disable(struct retu_wdt_dev *wdev)43{44 retu_write(wdev->rdev, RETU_REG_WATCHDOG, RETU_WDT_MAX_TIMER);45 cancel_delayed_work_sync(&wdev->ping_work);46}47 48static void retu_wdt_ping_work(struct work_struct *work)49{50 struct retu_wdt_dev *wdev = container_of(to_delayed_work(work),51 struct retu_wdt_dev, ping_work);52 retu_wdt_ping_enable(wdev);53}54 55static int retu_wdt_start(struct watchdog_device *wdog)56{57 struct retu_wdt_dev *wdev = watchdog_get_drvdata(wdog);58 59 retu_wdt_ping_disable(wdev);60 61 return retu_write(wdev->rdev, RETU_REG_WATCHDOG, wdog->timeout);62}63 64static int retu_wdt_stop(struct watchdog_device *wdog)65{66 struct retu_wdt_dev *wdev = watchdog_get_drvdata(wdog);67 68 retu_wdt_ping_enable(wdev);69 70 return 0;71}72 73static int retu_wdt_ping(struct watchdog_device *wdog)74{75 struct retu_wdt_dev *wdev = watchdog_get_drvdata(wdog);76 77 return retu_write(wdev->rdev, RETU_REG_WATCHDOG, wdog->timeout);78}79 80static int retu_wdt_set_timeout(struct watchdog_device *wdog,81 unsigned int timeout)82{83 struct retu_wdt_dev *wdev = watchdog_get_drvdata(wdog);84 85 wdog->timeout = timeout;86 return retu_write(wdev->rdev, RETU_REG_WATCHDOG, wdog->timeout);87}88 89static const struct watchdog_info retu_wdt_info = {90 .options = WDIOF_SETTIMEOUT | WDIOF_MAGICCLOSE | WDIOF_KEEPALIVEPING,91 .identity = "Retu watchdog",92};93 94static const struct watchdog_ops retu_wdt_ops = {95 .owner = THIS_MODULE,96 .start = retu_wdt_start,97 .stop = retu_wdt_stop,98 .ping = retu_wdt_ping,99 .set_timeout = retu_wdt_set_timeout,100};101 102static int retu_wdt_probe(struct platform_device *pdev)103{104 struct retu_dev *rdev = dev_get_drvdata(pdev->dev.parent);105 bool nowayout = WATCHDOG_NOWAYOUT;106 struct watchdog_device *retu_wdt;107 struct retu_wdt_dev *wdev;108 int ret;109 110 retu_wdt = devm_kzalloc(&pdev->dev, sizeof(*retu_wdt), GFP_KERNEL);111 if (!retu_wdt)112 return -ENOMEM;113 114 wdev = devm_kzalloc(&pdev->dev, sizeof(*wdev), GFP_KERNEL);115 if (!wdev)116 return -ENOMEM;117 118 retu_wdt->info = &retu_wdt_info;119 retu_wdt->ops = &retu_wdt_ops;120 retu_wdt->timeout = RETU_WDT_MAX_TIMER;121 retu_wdt->min_timeout = 0;122 retu_wdt->max_timeout = RETU_WDT_MAX_TIMER;123 retu_wdt->parent = &pdev->dev;124 125 watchdog_set_drvdata(retu_wdt, wdev);126 watchdog_set_nowayout(retu_wdt, nowayout);127 128 wdev->rdev = rdev;129 wdev->dev = &pdev->dev;130 131 ret = devm_delayed_work_autocancel(&pdev->dev, &wdev->ping_work,132 retu_wdt_ping_work);133 if (ret)134 return ret;135 136 ret = devm_watchdog_register_device(&pdev->dev, retu_wdt);137 if (ret < 0)138 return ret;139 140 if (nowayout)141 retu_wdt_ping(retu_wdt);142 else143 retu_wdt_ping_enable(wdev);144 145 return 0;146}147 148static struct platform_driver retu_wdt_driver = {149 .probe = retu_wdt_probe,150 .driver = {151 .name = "retu-wdt",152 },153};154module_platform_driver(retu_wdt_driver);155 156MODULE_ALIAS("platform:retu-wdt");157MODULE_DESCRIPTION("Retu watchdog");158MODULE_AUTHOR("Amit Kucheria");159MODULE_AUTHOR("Aaro Koskinen <aaro.koskinen@iki.fi>");160MODULE_LICENSE("GPL");161