[linux-2.6-block.git] / drivers / watchdog / stmp3xxx_rtc_wdt.c

// 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>");
Commit	Line	Data
2671a3a3	1	// SPDX-License-Identifier: GPL-2.0
de6303ab WS	2	/*
	3	* Watchdog driver for the RTC based watchdog in STMP3xxx and i.MX23/28
	4	*
cf82f52d	5	* Author: Wolfram Sang <kernel@pengutronix.de>
de6303ab WS	6	*
de6303ab WS	7	* Copyright (C) 2011-12 Wolfram Sang, Pengutronix
de6303ab	8	*/
de6303ab WS	9	#include <linux/kernel.h>
de6303ab WS	10	#include <linux/module.h>
de6303ab WS	11	#include <linux/watchdog.h>
	12	#include <linux/platform_device.h>
	13	#include <linux/stmp3xxx_rtc_wdt.h>
8d2fa171 HG	14	#include <linux/notifier.h>
8d2fa171 HG	15	#include <linux/reboot.h>
de6303ab WS	16
	17	#define WDOG_TICK_RATE 1000 /* 1 kHz clock */
	18	#define STMP3XXX_DEFAULT_TIMEOUT 19
	19	#define STMP3XXX_MAX_TIMEOUT (UINT_MAX / WDOG_TICK_RATE)
	20
	21	static int heartbeat = STMP3XXX_DEFAULT_TIMEOUT;
	22	module_param(heartbeat, uint, 0);
	23	MODULE_PARM_DESC(heartbeat, "Watchdog heartbeat period in seconds from 1 to "
	24	__MODULE_STRING(STMP3XXX_MAX_TIMEOUT) ", default "
	25	__MODULE_STRING(STMP3XXX_DEFAULT_TIMEOUT));
	26
	27	static int wdt_start(struct watchdog_device *wdd)
	28	{
	29	struct device *dev = watchdog_get_drvdata(wdd);
bc8fdfbe	30	struct stmp3xxx_wdt_pdata *pdata = dev_get_platdata(dev);
de6303ab WS	31
	32	pdata->wdt_set_timeout(dev->parent, wdd->timeout * WDOG_TICK_RATE);
	33	return 0;
	34	}
	35
	36	static int wdt_stop(struct watchdog_device *wdd)
	37	{
	38	struct device *dev = watchdog_get_drvdata(wdd);
bc8fdfbe	39	struct stmp3xxx_wdt_pdata *pdata = dev_get_platdata(dev);
de6303ab WS	40
	41	pdata->wdt_set_timeout(dev->parent, 0);
	42	return 0;
	43	}
	44
	45	static int wdt_set_timeout(struct watchdog_device *wdd, unsigned new_timeout)
	46	{
	47	wdd->timeout = new_timeout;
	48	return wdt_start(wdd);
	49	}
	50
	51	static const struct watchdog_info stmp3xxx_wdt_ident = {
	52	.options = WDIOF_MAGICCLOSE \| WDIOF_SETTIMEOUT \| WDIOF_KEEPALIVEPING,
	53	.identity = "STMP3XXX RTC Watchdog",
	54	};
	55
	56	static const struct watchdog_ops stmp3xxx_wdt_ops = {
	57	.owner = THIS_MODULE,
	58	.start = wdt_start,
	59	.stop = wdt_stop,
	60	.set_timeout = wdt_set_timeout,
	61	};
	62
	63	static struct watchdog_device stmp3xxx_wdd = {
	64	.info = &stmp3xxx_wdt_ident,
	65	.ops = &stmp3xxx_wdt_ops,
	66	.min_timeout = 1,
	67	.max_timeout = STMP3XXX_MAX_TIMEOUT,
	68	.status = WATCHDOG_NOWAYOUT_INIT_STATUS,
	69	};
	70
8d2fa171 HG	71	static int wdt_notify_sys(struct notifier_block *nb, unsigned long code,
	72	void *unused)
	73	{
8d2fa171 HG	74	switch (code) {
	75	case SYS_DOWN: /* keep enabled, system might crash while going down */
	76	break;
	77	case SYS_HALT: /* allow the system to actually halt */
	78	case SYS_POWER_OFF:
	79	wdt_stop(&stmp3xxx_wdd);
	80	break;
	81	}
	82
	83	return NOTIFY_DONE;
	84	}
	85
	86	static struct notifier_block wdt_notifier = {
	87	.notifier_call = wdt_notify_sys,
	88	};
	89
de6303ab WS	90	static int stmp3xxx_wdt_probe(struct platform_device *pdev)
	91	{
	92	int ret;
	93
	94	watchdog_set_drvdata(&stmp3xxx_wdd, &pdev->dev);
	95
	96	stmp3xxx_wdd.timeout = clamp_t(unsigned, heartbeat, 1, STMP3XXX_MAX_TIMEOUT);
6551881c	97	stmp3xxx_wdd.parent = &pdev->dev;
de6303ab WS	98
	99	ret = watchdog_register_device(&stmp3xxx_wdd);
	100	if (ret < 0) {
	101	dev_err(&pdev->dev, "cannot register watchdog device\n");
	102	return ret;
	103	}
	104
8d2fa171 HG	105	if (register_reboot_notifier(&wdt_notifier))
	106	dev_warn(&pdev->dev, "cannot register reboot notifier\n");
	107
de6303ab WS	108	dev_info(&pdev->dev, "initialized watchdog with heartbeat %ds\n",
	109	stmp3xxx_wdd.timeout);
	110	return 0;
	111	}
	112
	113	static int stmp3xxx_wdt_remove(struct platform_device *pdev)
	114	{
8d2fa171	115	unregister_reboot_notifier(&wdt_notifier);
de6303ab WS	116	watchdog_unregister_device(&stmp3xxx_wdd);
	117	return 0;
	118	}
	119
3281b85c JU	120	static int __maybe_unused stmp3xxx_wdt_suspend(struct device *dev)
	121	{
	122	struct watchdog_device *wdd = &stmp3xxx_wdd;
	123
	124	if (watchdog_active(wdd))
	125	return wdt_stop(wdd);
	126
	127	return 0;
	128	}
	129
	130	static int __maybe_unused stmp3xxx_wdt_resume(struct device *dev)
	131	{
	132	struct watchdog_device *wdd = &stmp3xxx_wdd;
	133
	134	if (watchdog_active(wdd))
	135	return wdt_start(wdd);
	136
	137	return 0;
	138	}
	139
	140	static SIMPLE_DEV_PM_OPS(stmp3xxx_wdt_pm_ops,
	141	stmp3xxx_wdt_suspend, stmp3xxx_wdt_resume);
	142
de6303ab WS	143	static struct platform_driver stmp3xxx_wdt_driver = {
	144	.driver = {
	145	.name = "stmp3xxx_rtc_wdt",
3281b85c	146	.pm = &stmp3xxx_wdt_pm_ops,
de6303ab WS	147	},
	148	.probe = stmp3xxx_wdt_probe,
	149	.remove = stmp3xxx_wdt_remove,
	150	};
	151	module_platform_driver(stmp3xxx_wdt_driver);
	152
	153	MODULE_DESCRIPTION("STMP3XXX RTC Watchdog Driver");
	154	MODULE_LICENSE("GPL v2");
cf82f52d	155	MODULE_AUTHOR("Wolfram Sang <kernel@pengutronix.de>");