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- // SPDX-License-Identifier: GPL-2.0
- /*
- * Watchdog driver for the RTC based watchdog in STMP3xxx and i.MX23/28
- *
- * Author: Wolfram Sang <kernel@pengutronix.de>
- *
- * Copyright (C) 2011-12 Wolfram Sang, Pengutronix
- */
- #include <linux/kernel.h>
- #include <linux/module.h>
- #include <linux/watchdog.h>
- #include <linux/platform_device.h>
- #include <linux/stmp3xxx_rtc_wdt.h>
- #include <linux/notifier.h>
- #include <linux/reboot.h>
- #define WDOG_TICK_RATE 1000 /* 1 kHz clock */
- #define STMP3XXX_DEFAULT_TIMEOUT 19
- #define STMP3XXX_MAX_TIMEOUT (UINT_MAX / WDOG_TICK_RATE)
- static int heartbeat = STMP3XXX_DEFAULT_TIMEOUT;
- module_param(heartbeat, uint, 0);
- MODULE_PARM_DESC(heartbeat, "Watchdog heartbeat period in seconds from 1 to "
- __MODULE_STRING(STMP3XXX_MAX_TIMEOUT) ", default "
- __MODULE_STRING(STMP3XXX_DEFAULT_TIMEOUT));
- static int wdt_start(struct watchdog_device *wdd)
- {
- struct device *dev = watchdog_get_drvdata(wdd);
- struct stmp3xxx_wdt_pdata *pdata = dev_get_platdata(dev);
- pdata->wdt_set_timeout(dev->parent, wdd->timeout * WDOG_TICK_RATE);
- return 0;
- }
- static int wdt_stop(struct watchdog_device *wdd)
- {
- struct device *dev = watchdog_get_drvdata(wdd);
- struct stmp3xxx_wdt_pdata *pdata = dev_get_platdata(dev);
- pdata->wdt_set_timeout(dev->parent, 0);
- return 0;
- }
- static int wdt_set_timeout(struct watchdog_device *wdd, unsigned new_timeout)
- {
- wdd->timeout = new_timeout;
- return wdt_start(wdd);
- }
- static const struct watchdog_info stmp3xxx_wdt_ident = {
- .options = WDIOF_MAGICCLOSE | WDIOF_SETTIMEOUT | WDIOF_KEEPALIVEPING,
- .identity = "STMP3XXX RTC Watchdog",
- };
- static const struct watchdog_ops stmp3xxx_wdt_ops = {
- .owner = THIS_MODULE,
- .start = wdt_start,
- .stop = wdt_stop,
- .set_timeout = wdt_set_timeout,
- };
- static struct watchdog_device stmp3xxx_wdd = {
- .info = &stmp3xxx_wdt_ident,
- .ops = &stmp3xxx_wdt_ops,
- .min_timeout = 1,
- .max_timeout = STMP3XXX_MAX_TIMEOUT,
- .status = WATCHDOG_NOWAYOUT_INIT_STATUS,
- };
- static int wdt_notify_sys(struct notifier_block *nb, unsigned long code,
- void *unused)
- {
- switch (code) {
- case SYS_DOWN: /* keep enabled, system might crash while going down */
- break;
- case SYS_HALT: /* allow the system to actually halt */
- case SYS_POWER_OFF:
- wdt_stop(&stmp3xxx_wdd);
- break;
- }
- return NOTIFY_DONE;
- }
- static struct notifier_block wdt_notifier = {
- .notifier_call = wdt_notify_sys,
- };
- static int stmp3xxx_wdt_probe(struct platform_device *pdev)
- {
- struct device *dev = &pdev->dev;
- int ret;
- watchdog_set_drvdata(&stmp3xxx_wdd, dev);
- stmp3xxx_wdd.timeout = clamp_t(unsigned, heartbeat, 1, STMP3XXX_MAX_TIMEOUT);
- stmp3xxx_wdd.parent = dev;
- ret = devm_watchdog_register_device(dev, &stmp3xxx_wdd);
- if (ret < 0)
- return ret;
- if (register_reboot_notifier(&wdt_notifier))
- dev_warn(dev, "cannot register reboot notifier\n");
- dev_info(dev, "initialized watchdog with heartbeat %ds\n",
- stmp3xxx_wdd.timeout);
- return 0;
- }
- static int stmp3xxx_wdt_remove(struct platform_device *pdev)
- {
- unregister_reboot_notifier(&wdt_notifier);
- return 0;
- }
- static int __maybe_unused stmp3xxx_wdt_suspend(struct device *dev)
- {
- struct watchdog_device *wdd = &stmp3xxx_wdd;
- if (watchdog_active(wdd))
- return wdt_stop(wdd);
- return 0;
- }
- static int __maybe_unused stmp3xxx_wdt_resume(struct device *dev)
- {
- struct watchdog_device *wdd = &stmp3xxx_wdd;
- if (watchdog_active(wdd))
- return wdt_start(wdd);
- return 0;
- }
- static SIMPLE_DEV_PM_OPS(stmp3xxx_wdt_pm_ops,
- stmp3xxx_wdt_suspend, stmp3xxx_wdt_resume);
- static struct platform_driver stmp3xxx_wdt_driver = {
- .driver = {
- .name = "stmp3xxx_rtc_wdt",
- .pm = &stmp3xxx_wdt_pm_ops,
- },
- .probe = stmp3xxx_wdt_probe,
- .remove = stmp3xxx_wdt_remove,
- };
- module_platform_driver(stmp3xxx_wdt_driver);
- MODULE_DESCRIPTION("STMP3XXX RTC Watchdog Driver");
- MODULE_LICENSE("GPL v2");
- MODULE_AUTHOR("Wolfram Sang <kernel@pengutronix.de>");
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