[deliverable/linux.git] / drivers / watchdog / bcm47xx_wdt.c

/*
 *  Watchdog driver for Broadcom BCM47XX
 *
 *  Copyright (C) 2008 Aleksandar Radovanovic <biblbroks@sezampro.rs>
 *  Copyright (C) 2009 Matthieu CASTET <castet.matthieu@free.fr>
 *  Copyright (C) 2012-2013 Hauke Mehrtens <hauke@hauke-m.de>
 *
 *  This program is free software; you can redistribute it and/or
 *  modify it under the terms of the GNU General Public License
 *  as published by the Free Software Foundation; either version
 *  2 of the License, or (at your option) any later version.
 */

#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt

#include <linux/bcm47xx_wdt.h>
#include <linux/bitops.h>
#include <linux/errno.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/moduleparam.h>
#include <linux/platform_device.h>
#include <linux/reboot.h>
#include <linux/types.h>
#include <linux/watchdog.h>
#include <linux/timer.h>
#include <linux/jiffies.h>

#define DRV_NAME		"bcm47xx_wdt"

#define WDT_DEFAULT_TIME	30	/* seconds */
#define WDT_SOFTTIMER_MAX	255	/* seconds */
#define WDT_SOFTTIMER_THRESHOLD	60	/* seconds */

static int timeout = WDT_DEFAULT_TIME;
static bool nowayout = WATCHDOG_NOWAYOUT;

module_param(timeout, int, 0);
MODULE_PARM_DESC(timeout, "Watchdog time in seconds. (default="
				__MODULE_STRING(WDT_DEFAULT_TIME) ")");

module_param(nowayout, bool, 0);
MODULE_PARM_DESC(nowayout,
		"Watchdog cannot be stopped once started (default="
				__MODULE_STRING(WATCHDOG_NOWAYOUT) ")");

static inline struct bcm47xx_wdt *bcm47xx_wdt_get(struct watchdog_device *wdd)
{
	return container_of(wdd, struct bcm47xx_wdt, wdd);
}

static int bcm47xx_wdt_hard_keepalive(struct watchdog_device *wdd)
{
	struct bcm47xx_wdt *wdt = bcm47xx_wdt_get(wdd);

	wdt->timer_set_ms(wdt, wdd->timeout * 1000);

	return 0;
}

static int bcm47xx_wdt_hard_start(struct watchdog_device *wdd)
{
	return 0;
}

static int bcm47xx_wdt_hard_stop(struct watchdog_device *wdd)
{
	struct bcm47xx_wdt *wdt = bcm47xx_wdt_get(wdd);

	wdt->timer_set(wdt, 0);

	return 0;
}

static int bcm47xx_wdt_hard_set_timeout(struct watchdog_device *wdd,
					unsigned int new_time)
{
	struct bcm47xx_wdt *wdt = bcm47xx_wdt_get(wdd);
	u32 max_timer = wdt->max_timer_ms;

	if (new_time < 1 || new_time > max_timer / 1000) {
		pr_warn("timeout value must be 1<=x<=%d, using %d\n",
			max_timer / 1000, new_time);
		return -EINVAL;
	}

	wdd->timeout = new_time;
	return 0;
}

static struct watchdog_ops bcm47xx_wdt_hard_ops = {
	.owner		= THIS_MODULE,
	.start		= bcm47xx_wdt_hard_start,
	.stop		= bcm47xx_wdt_hard_stop,
	.ping		= bcm47xx_wdt_hard_keepalive,
	.set_timeout	= bcm47xx_wdt_hard_set_timeout,
};

static void bcm47xx_wdt_soft_timer_tick(unsigned long data)
{
	struct bcm47xx_wdt *wdt = (struct bcm47xx_wdt *)data;
	u32 next_tick = min(wdt->wdd.timeout * 1000, wdt->max_timer_ms);

	if (!atomic_dec_and_test(&wdt->soft_ticks)) {
		wdt->timer_set_ms(wdt, next_tick);
		mod_timer(&wdt->soft_timer, jiffies + HZ);
	} else {
		pr_crit("Watchdog will fire soon!!!\n");
	}
}

static int bcm47xx_wdt_soft_keepalive(struct watchdog_device *wdd)
{
	struct bcm47xx_wdt *wdt = bcm47xx_wdt_get(wdd);

	atomic_set(&wdt->soft_ticks, wdd->timeout);

	return 0;
}

static int bcm47xx_wdt_soft_start(struct watchdog_device *wdd)
{
	struct bcm47xx_wdt *wdt = bcm47xx_wdt_get(wdd);

	bcm47xx_wdt_soft_keepalive(wdd);
	bcm47xx_wdt_soft_timer_tick((unsigned long)wdt);

	return 0;
}

static int bcm47xx_wdt_soft_stop(struct watchdog_device *wdd)
{
	struct bcm47xx_wdt *wdt = bcm47xx_wdt_get(wdd);

	del_timer_sync(&wdt->soft_timer);
	wdt->timer_set(wdt, 0);

	return 0;
}

static int bcm47xx_wdt_soft_set_timeout(struct watchdog_device *wdd,
					unsigned int new_time)
{
	if (new_time < 1 || new_time > WDT_SOFTTIMER_MAX) {
		pr_warn("timeout value must be 1<=x<=%d, using %d\n",
			WDT_SOFTTIMER_MAX, new_time);
		return -EINVAL;
	}

	wdd->timeout = new_time;
	return 0;
}

static const struct watchdog_info bcm47xx_wdt_info = {
	.identity	= DRV_NAME,
	.options	= WDIOF_SETTIMEOUT |
				WDIOF_KEEPALIVEPING |
				WDIOF_MAGICCLOSE,
};

static int bcm47xx_wdt_notify_sys(struct notifier_block *this,
				  unsigned long code, void *unused)
{
	struct bcm47xx_wdt *wdt;

	wdt = container_of(this, struct bcm47xx_wdt, notifier);
	if (code == SYS_DOWN || code == SYS_HALT)
		wdt->wdd.ops->stop(&wdt->wdd);
	return NOTIFY_DONE;
}

static struct watchdog_ops bcm47xx_wdt_soft_ops = {
	.owner		= THIS_MODULE,
	.start		= bcm47xx_wdt_soft_start,
	.stop		= bcm47xx_wdt_soft_stop,
	.ping		= bcm47xx_wdt_soft_keepalive,
	.set_timeout	= bcm47xx_wdt_soft_set_timeout,
};

static int bcm47xx_wdt_probe(struct platform_device *pdev)
{
	int ret;
	bool soft;
	struct bcm47xx_wdt *wdt = dev_get_platdata(&pdev->dev);

	if (!wdt)
		return -ENXIO;

	soft = wdt->max_timer_ms < WDT_SOFTTIMER_THRESHOLD * 1000;

	if (soft) {
		wdt->wdd.ops = &bcm47xx_wdt_soft_ops;
		setup_timer(&wdt->soft_timer, bcm47xx_wdt_soft_timer_tick,
			    (long unsigned int)wdt);
	} else {
		wdt->wdd.ops = &bcm47xx_wdt_hard_ops;
	}

	wdt->wdd.info = &bcm47xx_wdt_info;
	wdt->wdd.timeout = WDT_DEFAULT_TIME;
	ret = wdt->wdd.ops->set_timeout(&wdt->wdd, timeout);
	if (ret)
		goto err_timer;
	watchdog_set_nowayout(&wdt->wdd, nowayout);

	wdt->notifier.notifier_call = &bcm47xx_wdt_notify_sys;

	ret = register_reboot_notifier(&wdt->notifier);
	if (ret)
		goto err_timer;

	ret = watchdog_register_device(&wdt->wdd);
	if (ret)
		goto err_notifier;

	dev_info(&pdev->dev, "BCM47xx Watchdog Timer enabled (%d seconds%s%s)\n",
		timeout, nowayout ? ", nowayout" : "",
		soft ? ", Software Timer" : "");
	return 0;

err_notifier:
	unregister_reboot_notifier(&wdt->notifier);
err_timer:
	if (soft)
		del_timer_sync(&wdt->soft_timer);

	return ret;
}

static int bcm47xx_wdt_remove(struct platform_device *pdev)
{
	struct bcm47xx_wdt *wdt = dev_get_platdata(&pdev->dev);

	if (!wdt)
		return -ENXIO;

	watchdog_unregister_device(&wdt->wdd);
	unregister_reboot_notifier(&wdt->notifier);

	return 0;
}

static struct platform_driver bcm47xx_wdt_driver = {
	.driver		= {
		.owner	= THIS_MODULE,
		.name	= "bcm47xx-wdt",
	},
	.probe		= bcm47xx_wdt_probe,
	.remove		= bcm47xx_wdt_remove,
};

module_platform_driver(bcm47xx_wdt_driver);

MODULE_AUTHOR("Aleksandar Radovanovic");
MODULE_AUTHOR("Hauke Mehrtens <hauke@hauke-m.de>");
MODULE_DESCRIPTION("Watchdog driver for Broadcom BCM47xx");
MODULE_LICENSE("GPL");
Commit	Line	Data
	1	/*
	2	* Watchdog driver for Broadcom BCM47XX
	3	*
	4	* Copyright (C) 2008 Aleksandar Radovanovic <biblbroks@sezampro.rs>
	5	* Copyright (C) 2009 Matthieu CASTET <castet.matthieu@free.fr>
	6	* Copyright (C) 2012-2013 Hauke Mehrtens <hauke@hauke-m.de>
	7	*
	8	* This program is free software; you can redistribute it and/or
	9	* modify it under the terms of the GNU General Public License
	10	* as published by the Free Software Foundation; either version
	11	* 2 of the License, or (at your option) any later version.
	12	*/
	13
	14	#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
	15
	16	#include <linux/bcm47xx_wdt.h>
	17	#include <linux/bitops.h>
	18	#include <linux/errno.h>
	19	#include <linux/kernel.h>
	20	#include <linux/module.h>
	21	#include <linux/moduleparam.h>
	22	#include <linux/platform_device.h>
	23	#include <linux/reboot.h>
	24	#include <linux/types.h>
	25	#include <linux/watchdog.h>
	26	#include <linux/timer.h>
	27	#include <linux/jiffies.h>
	28
	29	#define DRV_NAME "bcm47xx_wdt"
	30
	31	#define WDT_DEFAULT_TIME 30 /* seconds */
	32	#define WDT_SOFTTIMER_MAX 255 /* seconds */
	33	#define WDT_SOFTTIMER_THRESHOLD 60 /* seconds */
	34
	35	static int timeout = WDT_DEFAULT_TIME;
	36	static bool nowayout = WATCHDOG_NOWAYOUT;
	37
	38	module_param(timeout, int, 0);
	39	MODULE_PARM_DESC(timeout, "Watchdog time in seconds. (default="
	40	__MODULE_STRING(WDT_DEFAULT_TIME) ")");
	41
	42	module_param(nowayout, bool, 0);
	43	MODULE_PARM_DESC(nowayout,
	44	"Watchdog cannot be stopped once started (default="
	45	__MODULE_STRING(WATCHDOG_NOWAYOUT) ")");
	46
	47	static inline struct bcm47xx_wdt bcm47xx_wdt_get(struct watchdog_device wdd)
	48	{
	49	return container_of(wdd, struct bcm47xx_wdt, wdd);
	50	}
	51
	52	static int bcm47xx_wdt_hard_keepalive(struct watchdog_device *wdd)
	53	{
	54	struct bcm47xx_wdt *wdt = bcm47xx_wdt_get(wdd);
	55
	56	wdt->timer_set_ms(wdt, wdd->timeout * 1000);
	57
	58	return 0;
	59	}
	60
	61	static int bcm47xx_wdt_hard_start(struct watchdog_device *wdd)
	62	{
	63	return 0;
	64	}
	65
	66	static int bcm47xx_wdt_hard_stop(struct watchdog_device *wdd)
	67	{
	68	struct bcm47xx_wdt *wdt = bcm47xx_wdt_get(wdd);
	69
	70	wdt->timer_set(wdt, 0);
	71
	72	return 0;
	73	}
	74
	75	static int bcm47xx_wdt_hard_set_timeout(struct watchdog_device *wdd,
	76	unsigned int new_time)
	77	{
	78	struct bcm47xx_wdt *wdt = bcm47xx_wdt_get(wdd);
	79	u32 max_timer = wdt->max_timer_ms;
	80
	81	if (new_time < 1 \|\| new_time > max_timer / 1000) {
	82	pr_warn("timeout value must be 1<=x<=%d, using %d\n",
	83	max_timer / 1000, new_time);
	84	return -EINVAL;
	85	}
	86
	87	wdd->timeout = new_time;
	88	return 0;
	89	}
	90
	91	static struct watchdog_ops bcm47xx_wdt_hard_ops = {
	92	.owner = THIS_MODULE,
	93	.start = bcm47xx_wdt_hard_start,
	94	.stop = bcm47xx_wdt_hard_stop,
	95	.ping = bcm47xx_wdt_hard_keepalive,
	96	.set_timeout = bcm47xx_wdt_hard_set_timeout,
	97	};
	98
	99	static void bcm47xx_wdt_soft_timer_tick(unsigned long data)
	100	{
	101	struct bcm47xx_wdt wdt = (struct bcm47xx_wdt )data;
	102	u32 next_tick = min(wdt->wdd.timeout * 1000, wdt->max_timer_ms);
	103
	104	if (!atomic_dec_and_test(&wdt->soft_ticks)) {
	105	wdt->timer_set_ms(wdt, next_tick);
	106	mod_timer(&wdt->soft_timer, jiffies + HZ);
	107	} else {
	108	pr_crit("Watchdog will fire soon!!!\n");
	109	}
	110	}
	111
	112	static int bcm47xx_wdt_soft_keepalive(struct watchdog_device *wdd)
	113	{
	114	struct bcm47xx_wdt *wdt = bcm47xx_wdt_get(wdd);
	115
	116	atomic_set(&wdt->soft_ticks, wdd->timeout);
	117
	118	return 0;
	119	}
	120
	121	static int bcm47xx_wdt_soft_start(struct watchdog_device *wdd)
	122	{
	123	struct bcm47xx_wdt *wdt = bcm47xx_wdt_get(wdd);
	124
	125	bcm47xx_wdt_soft_keepalive(wdd);
	126	bcm47xx_wdt_soft_timer_tick((unsigned long)wdt);
	127
	128	return 0;
	129	}
	130
	131	static int bcm47xx_wdt_soft_stop(struct watchdog_device *wdd)
	132	{
	133	struct bcm47xx_wdt *wdt = bcm47xx_wdt_get(wdd);
	134
	135	del_timer_sync(&wdt->soft_timer);
	136	wdt->timer_set(wdt, 0);
	137
	138	return 0;
	139	}
	140
	141	static int bcm47xx_wdt_soft_set_timeout(struct watchdog_device *wdd,
	142	unsigned int new_time)
	143	{
	144	if (new_time < 1 \|\| new_time > WDT_SOFTTIMER_MAX) {
	145	pr_warn("timeout value must be 1<=x<=%d, using %d\n",
	146	WDT_SOFTTIMER_MAX, new_time);
	147	return -EINVAL;
	148	}
	149
	150	wdd->timeout = new_time;
	151	return 0;
	152	}
	153
	154	static const struct watchdog_info bcm47xx_wdt_info = {
	155	.identity = DRV_NAME,
	156	.options = WDIOF_SETTIMEOUT \|
	157	WDIOF_KEEPALIVEPING \|
	158	WDIOF_MAGICCLOSE,
	159	};
	160
	161	static int bcm47xx_wdt_notify_sys(struct notifier_block *this,
	162	unsigned long code, void *unused)
	163	{
	164	struct bcm47xx_wdt *wdt;
	165
	166	wdt = container_of(this, struct bcm47xx_wdt, notifier);
	167	if (code == SYS_DOWN \|\| code == SYS_HALT)
	168	wdt->wdd.ops->stop(&wdt->wdd);
	169	return NOTIFY_DONE;
	170	}
	171
	172	static struct watchdog_ops bcm47xx_wdt_soft_ops = {
	173	.owner = THIS_MODULE,
	174	.start = bcm47xx_wdt_soft_start,
	175	.stop = bcm47xx_wdt_soft_stop,
	176	.ping = bcm47xx_wdt_soft_keepalive,
	177	.set_timeout = bcm47xx_wdt_soft_set_timeout,
	178	};
	179
	180	static int bcm47xx_wdt_probe(struct platform_device *pdev)
	181	{
	182	int ret;
	183	bool soft;
	184	struct bcm47xx_wdt *wdt = dev_get_platdata(&pdev->dev);
	185
	186	if (!wdt)
	187	return -ENXIO;
	188
	189	soft = wdt->max_timer_ms < WDT_SOFTTIMER_THRESHOLD * 1000;
	190
	191	if (soft) {
	192	wdt->wdd.ops = &bcm47xx_wdt_soft_ops;
	193	setup_timer(&wdt->soft_timer, bcm47xx_wdt_soft_timer_tick,
	194	(long unsigned int)wdt);
	195	} else {
	196	wdt->wdd.ops = &bcm47xx_wdt_hard_ops;
	197	}
	198
	199	wdt->wdd.info = &bcm47xx_wdt_info;
	200	wdt->wdd.timeout = WDT_DEFAULT_TIME;
	201	ret = wdt->wdd.ops->set_timeout(&wdt->wdd, timeout);
	202	if (ret)
	203	goto err_timer;
	204	watchdog_set_nowayout(&wdt->wdd, nowayout);
	205
	206	wdt->notifier.notifier_call = &bcm47xx_wdt_notify_sys;
	207
	208	ret = register_reboot_notifier(&wdt->notifier);
	209	if (ret)
	210	goto err_timer;
	211
	212	ret = watchdog_register_device(&wdt->wdd);
	213	if (ret)
	214	goto err_notifier;
	215
	216	dev_info(&pdev->dev, "BCM47xx Watchdog Timer enabled (%d seconds%s%s)\n",
	217	timeout, nowayout ? ", nowayout" : "",
	218	soft ? ", Software Timer" : "");
	219	return 0;
	220
	221	err_notifier:
	222	unregister_reboot_notifier(&wdt->notifier);
	223	err_timer:
	224	if (soft)
	225	del_timer_sync(&wdt->soft_timer);
	226
	227	return ret;
	228	}
	229
	230	static int bcm47xx_wdt_remove(struct platform_device *pdev)
	231	{
	232	struct bcm47xx_wdt *wdt = dev_get_platdata(&pdev->dev);
	233
	234	if (!wdt)
	235	return -ENXIO;
	236
	237	watchdog_unregister_device(&wdt->wdd);
	238	unregister_reboot_notifier(&wdt->notifier);
	239
	240	return 0;
	241	}
	242
	243	static struct platform_driver bcm47xx_wdt_driver = {
	244	.driver = {
	245	.owner = THIS_MODULE,
	246	.name = "bcm47xx-wdt",
	247	},
	248	.probe = bcm47xx_wdt_probe,
	249	.remove = bcm47xx_wdt_remove,
	250	};
	251
	252	module_platform_driver(bcm47xx_wdt_driver);
	253
	254	MODULE_AUTHOR("Aleksandar Radovanovic");
	255	MODULE_AUTHOR("Hauke Mehrtens <hauke@hauke-m.de>");
	256	MODULE_DESCRIPTION("Watchdog driver for Broadcom BCM47xx");
	257	MODULE_LICENSE("GPL");