diff options
Diffstat (limited to 'drivers/watchdog/stmp3xxx_rtc_wdt.c')
| -rw-r--r-- | drivers/watchdog/stmp3xxx_rtc_wdt.c | 155 |
1 files changed, 155 insertions, 0 deletions
diff --git a/drivers/watchdog/stmp3xxx_rtc_wdt.c b/drivers/watchdog/stmp3xxx_rtc_wdt.c new file mode 100644 index 000000000..994c54cc6 --- /dev/null +++ b/drivers/watchdog/stmp3xxx_rtc_wdt.c @@ -0,0 +1,155 @@ +// 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) +{ + int ret; + + watchdog_set_drvdata(&stmp3xxx_wdd, &pdev->dev); + + stmp3xxx_wdd.timeout = clamp_t(unsigned, heartbeat, 1, STMP3XXX_MAX_TIMEOUT); + stmp3xxx_wdd.parent = &pdev->dev; + + ret = watchdog_register_device(&stmp3xxx_wdd); + if (ret < 0) { + dev_err(&pdev->dev, "cannot register watchdog device\n"); + return ret; + } + + if (register_reboot_notifier(&wdt_notifier)) + dev_warn(&pdev->dev, "cannot register reboot notifier\n"); + + dev_info(&pdev->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); + watchdog_unregister_device(&stmp3xxx_wdd); + 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>"); |