| // 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) { |
| dev_err(dev, "cannot register watchdog device\n"); |
| 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>"); |