[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>
 *
 *  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/bitops.h>
#include <linux/errno.h>
#include <linux/init.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/moduleparam.h>
#include <linux/reboot.h>
#include <linux/types.h>
#include <linux/watchdog.h>
#include <linux/timer.h>
#include <linux/jiffies.h>
#include <linux/ssb/ssb_embedded.h>
#include <asm/mach-bcm47xx/bcm47xx.h>

#define DRV_NAME		"bcm47xx_wdt"

#define WDT_DEFAULT_TIME	30	/* seconds */
#define WDT_MAX_TIME		255	/* seconds */

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

module_param(wdt_time, int, 0);
MODULE_PARM_DESC(wdt_time, "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 struct timer_list wdt_timer;
static atomic_t ticks;

static inline void bcm47xx_wdt_hw_start(void)
{
	/* this is 2,5s on 100Mhz clock  and 2s on 133 Mhz */
	switch (bcm47xx_bus_type) {
#ifdef CONFIG_BCM47XX_SSB
	case BCM47XX_BUS_TYPE_SSB:
		ssb_watchdog_timer_set(&bcm47xx_bus.ssb, 0xfffffff);
		break;
#endif
#ifdef CONFIG_BCM47XX_BCMA
	case BCM47XX_BUS_TYPE_BCMA:
		bcma_chipco_watchdog_timer_set(&bcm47xx_bus.bcma.bus.drv_cc,
					       0xfffffff);
		break;
#endif
	}
}

static inline int bcm47xx_wdt_hw_stop(void)
{
	switch (bcm47xx_bus_type) {
#ifdef CONFIG_BCM47XX_SSB
	case BCM47XX_BUS_TYPE_SSB:
		return ssb_watchdog_timer_set(&bcm47xx_bus.ssb, 0);
#endif
#ifdef CONFIG_BCM47XX_BCMA
	case BCM47XX_BUS_TYPE_BCMA:
		bcma_chipco_watchdog_timer_set(&bcm47xx_bus.bcma.bus.drv_cc, 0);
		return 0;
#endif
	}
	return -EINVAL;
}

static void bcm47xx_timer_tick(unsigned long unused)
{
	if (!atomic_dec_and_test(&ticks)) {
		bcm47xx_wdt_hw_start();
		mod_timer(&wdt_timer, jiffies + HZ);
	} else {
		pr_crit("Watchdog will fire soon!!!\n");
	}
}

static int bcm47xx_wdt_keepalive(struct watchdog_device *wdd)
{
	atomic_set(&ticks, wdt_time);

	return 0;
}

static int bcm47xx_wdt_start(struct watchdog_device *wdd)
{
	bcm47xx_wdt_pet();
	bcm47xx_timer_tick(0);

	return 0;
}

static int bcm47xx_wdt_stop(struct watchdog_device *wdd)
{
	del_timer_sync(&wdt_timer);
	bcm47xx_wdt_hw_stop();

	return 0;
}

static int bcm47xx_wdt_set_timeout(struct watchdog_device *wdd,
				   unsigned int new_time)
{
	if ((new_time <= 0) || (new_time > WDT_MAX_TIME))
		return -EINVAL;

	wdt_time = 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)
{
	if (code == SYS_DOWN || code == SYS_HALT)
		bcm47xx_wdt_stop();
	return NOTIFY_DONE;
}

static struct watchdog_ops bcm47xx_wdt_ops = {
	.owner		= THIS_MODULE,
	.start		= bcm47xx_wdt_start,
	.stop		= bcm47xx_wdt_stop,
	.ping		= bcm47xx_wdt_keepalive,
	.set_timeout	= bcm47xx_wdt_set_timeout,
};

static struct watchdog_device bcm47xx_wdt_wdd = {
	.info		= &bcm47xx_wdt_info,
	.ops		= &bcm47xx_wdt_ops,
};

static struct notifier_block bcm47xx_wdt_notifier = {
	.notifier_call = bcm47xx_wdt_notify_sys,
};

static int __init bcm47xx_wdt_init(void)
{
	int ret;

	if (bcm47xx_wdt_hw_stop() < 0)
		return -ENODEV;

	setup_timer(&wdt_timer, bcm47xx_timer_tick, 0L);

	if (bcm47xx_wdt_settimeout(wdt_time)) {
		bcm47xx_wdt_settimeout(WDT_DEFAULT_TIME);
		pr_info("wdt_time value must be 0 < wdt_time < %d, using %d\n",
			(WDT_MAX_TIME + 1), wdt_time);
	}
	watchdog_set_nowayout(&bcm47xx_wdt_wdd, nowayout);

	ret = register_reboot_notifier(&bcm47xx_wdt_notifier);
	if (ret)
		return ret;

	ret = watchdog_register_device(&bcm47xx_wdt_wdd);
	if (ret) {
		unregister_reboot_notifier(&bcm47xx_wdt_notifier);
		return ret;
	}

	pr_info("BCM47xx Watchdog Timer enabled (%d seconds%s)\n",
		wdt_time, nowayout ? ", nowayout" : "");
	return 0;
}

static void __exit bcm47xx_wdt_exit(void)
{
	watchdog_unregister_device(&bcm47xx_wdt_wdd);

	unregister_reboot_notifier(&bcm47xx_wdt_notifier);
}

module_init(bcm47xx_wdt_init);
module_exit(bcm47xx_wdt_exit);

MODULE_AUTHOR("Aleksandar Radovanovic");
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	*
	7	* This program is free software; you can redistribute it and/or
	8	* modify it under the terms of the GNU General Public License
	9	* as published by the Free Software Foundation; either version
	10	* 2 of the License, or (at your option) any later version.
	11	*/
	12
	13	#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
	14
	15	#include <linux/bitops.h>
	16	#include <linux/errno.h>
	17	#include <linux/init.h>
	18	#include <linux/kernel.h>
	19	#include <linux/module.h>
	20	#include <linux/moduleparam.h>
	21	#include <linux/reboot.h>
	22	#include <linux/types.h>
	23	#include <linux/watchdog.h>
	24	#include <linux/timer.h>
	25	#include <linux/jiffies.h>
	26	#include <linux/ssb/ssb_embedded.h>
	27	#include <asm/mach-bcm47xx/bcm47xx.h>
	28
	29	#define DRV_NAME "bcm47xx_wdt"
	30
	31	#define WDT_DEFAULT_TIME 30 /* seconds */
	32	#define WDT_MAX_TIME 255 /* seconds */
	33
	34	static int wdt_time = WDT_DEFAULT_TIME;
	35	static bool nowayout = WATCHDOG_NOWAYOUT;
	36
	37	module_param(wdt_time, int, 0);
	38	MODULE_PARM_DESC(wdt_time, "Watchdog time in seconds. (default="
	39	__MODULE_STRING(WDT_DEFAULT_TIME) ")");
	40
	41	module_param(nowayout, bool, 0);
	42	MODULE_PARM_DESC(nowayout,
	43	"Watchdog cannot be stopped once started (default="
	44	__MODULE_STRING(WATCHDOG_NOWAYOUT) ")");
	45
	46	static struct timer_list wdt_timer;
	47	static atomic_t ticks;
	48
	49	static inline void bcm47xx_wdt_hw_start(void)
	50	{
	51	/* this is 2,5s on 100Mhz clock and 2s on 133 Mhz */
	52	switch (bcm47xx_bus_type) {
	53	#ifdef CONFIG_BCM47XX_SSB
	54	case BCM47XX_BUS_TYPE_SSB:
	55	ssb_watchdog_timer_set(&bcm47xx_bus.ssb, 0xfffffff);
	56	break;
	57	#endif
	58	#ifdef CONFIG_BCM47XX_BCMA
	59	case BCM47XX_BUS_TYPE_BCMA:
	60	bcma_chipco_watchdog_timer_set(&bcm47xx_bus.bcma.bus.drv_cc,
	61	0xfffffff);
	62	break;
	63	#endif
	64	}
	65	}
	66
	67	static inline int bcm47xx_wdt_hw_stop(void)
	68	{
	69	switch (bcm47xx_bus_type) {
	70	#ifdef CONFIG_BCM47XX_SSB
	71	case BCM47XX_BUS_TYPE_SSB:
	72	return ssb_watchdog_timer_set(&bcm47xx_bus.ssb, 0);
	73	#endif
	74	#ifdef CONFIG_BCM47XX_BCMA
	75	case BCM47XX_BUS_TYPE_BCMA:
	76	bcma_chipco_watchdog_timer_set(&bcm47xx_bus.bcma.bus.drv_cc, 0);
	77	return 0;
	78	#endif
	79	}
	80	return -EINVAL;
	81	}
	82
	83	static void bcm47xx_timer_tick(unsigned long unused)
	84	{
	85	if (!atomic_dec_and_test(&ticks)) {
	86	bcm47xx_wdt_hw_start();
	87	mod_timer(&wdt_timer, jiffies + HZ);
	88	} else {
	89	pr_crit("Watchdog will fire soon!!!\n");
	90	}
	91	}
	92
	93	static int bcm47xx_wdt_keepalive(struct watchdog_device *wdd)
	94	{
	95	atomic_set(&ticks, wdt_time);
	96
	97	return 0;
	98	}
	99
	100	static int bcm47xx_wdt_start(struct watchdog_device *wdd)
	101	{
	102	bcm47xx_wdt_pet();
	103	bcm47xx_timer_tick(0);
	104
	105	return 0;
	106	}
	107
	108	static int bcm47xx_wdt_stop(struct watchdog_device *wdd)
	109	{
	110	del_timer_sync(&wdt_timer);
	111	bcm47xx_wdt_hw_stop();
	112
	113	return 0;
	114	}
	115
	116	static int bcm47xx_wdt_set_timeout(struct watchdog_device *wdd,
	117	unsigned int new_time)
	118	{
	119	if ((new_time <= 0) \|\| (new_time > WDT_MAX_TIME))
	120	return -EINVAL;
	121
	122	wdt_time = new_time;
	123	return 0;
	124	}
	125
	126	static const struct watchdog_info bcm47xx_wdt_info = {
	127	.identity = DRV_NAME,
	128	.options = WDIOF_SETTIMEOUT \|
	129	WDIOF_KEEPALIVEPING \|
	130	WDIOF_MAGICCLOSE,
	131	};
	132
	133	static int bcm47xx_wdt_notify_sys(struct notifier_block *this,
	134	unsigned long code, void *unused)
	135	{
	136	if (code == SYS_DOWN \|\| code == SYS_HALT)
	137	bcm47xx_wdt_stop();
	138	return NOTIFY_DONE;
	139	}
	140
	141	static struct watchdog_ops bcm47xx_wdt_ops = {
	142	.owner = THIS_MODULE,
	143	.start = bcm47xx_wdt_start,
	144	.stop = bcm47xx_wdt_stop,
	145	.ping = bcm47xx_wdt_keepalive,
	146	.set_timeout = bcm47xx_wdt_set_timeout,
	147	};
	148
	149	static struct watchdog_device bcm47xx_wdt_wdd = {
	150	.info = &bcm47xx_wdt_info,
	151	.ops = &bcm47xx_wdt_ops,
	152	};
	153
	154	static struct notifier_block bcm47xx_wdt_notifier = {
	155	.notifier_call = bcm47xx_wdt_notify_sys,
	156	};
	157
	158	static int __init bcm47xx_wdt_init(void)
	159	{
	160	int ret;
	161
	162	if (bcm47xx_wdt_hw_stop() < 0)
	163	return -ENODEV;
	164
	165	setup_timer(&wdt_timer, bcm47xx_timer_tick, 0L);
	166
	167	if (bcm47xx_wdt_settimeout(wdt_time)) {
	168	bcm47xx_wdt_settimeout(WDT_DEFAULT_TIME);
	169	pr_info("wdt_time value must be 0 < wdt_time < %d, using %d\n",
	170	(WDT_MAX_TIME + 1), wdt_time);
	171	}
	172	watchdog_set_nowayout(&bcm47xx_wdt_wdd, nowayout);
	173
	174	ret = register_reboot_notifier(&bcm47xx_wdt_notifier);
	175	if (ret)
	176	return ret;
	177
	178	ret = watchdog_register_device(&bcm47xx_wdt_wdd);
	179	if (ret) {
	180	unregister_reboot_notifier(&bcm47xx_wdt_notifier);
	181	return ret;
	182	}
	183
	184	pr_info("BCM47xx Watchdog Timer enabled (%d seconds%s)\n",
	185	wdt_time, nowayout ? ", nowayout" : "");
	186	return 0;
	187	}
	188
	189	static void __exit bcm47xx_wdt_exit(void)
	190	{
	191	watchdog_unregister_device(&bcm47xx_wdt_wdd);
	192
	193	unregister_reboot_notifier(&bcm47xx_wdt_notifier);
	194	}
	195
	196	module_init(bcm47xx_wdt_init);
	197	module_exit(bcm47xx_wdt_exit);
	198
	199	MODULE_AUTHOR("Aleksandar Radovanovic");
	200	MODULE_DESCRIPTION("Watchdog driver for Broadcom BCM47xx");
	201	MODULE_LICENSE("GPL");