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

/*
 *	IndyDog	0.3	A Hardware Watchdog Device for SGI IP22
 *
 *	(c) Copyright 2002 Guido Guenther <agx@sigxcpu.org>, All Rights Reserved.
 *
 *	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.
 *
 *	based on softdog.c by Alan Cox <alan@redhat.com>
 */

#include <linux/module.h>
#include <linux/moduleparam.h>
#include <linux/types.h>
#include <linux/kernel.h>
#include <linux/fs.h>
#include <linux/mm.h>
#include <linux/miscdevice.h>
#include <linux/watchdog.h>
#include <linux/notifier.h>
#include <linux/reboot.h>
#include <linux/init.h>
#include <asm/uaccess.h>
#include <asm/sgi/mc.h>

#define PFX "indydog: "
static int indydog_alive;

#define WATCHDOG_TIMEOUT 30		/* 30 sec default timeout */

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

static void indydog_start(void)
{
	u32 mc_ctrl0 = sgimc->cpuctrl0;

	mc_ctrl0 = sgimc->cpuctrl0 | SGIMC_CCTRL0_WDOG;
	sgimc->cpuctrl0 = mc_ctrl0;
}

static void indydog_stop(void)
{
	u32 mc_ctrl0 = sgimc->cpuctrl0;

	mc_ctrl0 &= ~SGIMC_CCTRL0_WDOG;
	sgimc->cpuctrl0 = mc_ctrl0;

	printk(KERN_INFO PFX "Stopped watchdog timer.\n");
}

static void indydog_ping(void)
{
	sgimc->watchdogt = 0;
}

/*
 *	Allow only one person to hold it open
 */
static int indydog_open(struct inode *inode, struct file *file)
{
	if (indydog_alive)
		return -EBUSY;

	if (nowayout)
		__module_get(THIS_MODULE);

	/* Activate timer */
	indydog_start();
	indydog_ping();

	indydog_alive = 1;
	printk(KERN_INFO "Started watchdog timer.\n");

	return nonseekable_open(inode, file);
}

static int indydog_release(struct inode *inode, struct file *file)
{
	/* Shut off the timer.
	 * Lock it in if it's a module and we defined ...NOWAYOUT */
	if (!nowayout)
		indydog_stop();		/* Turn the WDT off */

	indydog_alive = 0;

	return 0;
}

static ssize_t indydog_write(struct file *file, const char *data, size_t len, loff_t *ppos)
{
	/* Refresh the timer. */
	if (len) {
		indydog_ping();
	}
	return len;
}

static int indydog_ioctl(struct inode *inode, struct file *file,
	unsigned int cmd, unsigned long arg)
{
	int options, retval = -EINVAL;
	static struct watchdog_info ident = {
		.options		= WDIOF_KEEPALIVEPING |
					  WDIOF_MAGICCLOSE,
		.firmware_version	= 0,
		.identity		= "Hardware Watchdog for SGI IP22",
	};

	switch (cmd) {
		default:
			return -ENOTTY;
		case WDIOC_GETSUPPORT:
			if (copy_to_user((struct watchdog_info *)arg,
					 &ident, sizeof(ident)))
				return -EFAULT;
			return 0;
		case WDIOC_GETSTATUS:
		case WDIOC_GETBOOTSTATUS:
			return put_user(0,(int *)arg);
		case WDIOC_KEEPALIVE:
			indydog_ping();
			return 0;
		case WDIOC_GETTIMEOUT:
			return put_user(WATCHDOG_TIMEOUT,(int *)arg);
		case WDIOC_SETOPTIONS:
		{
			if (get_user(options, (int *)arg))
				return -EFAULT;

			if (options & WDIOS_DISABLECARD) {
				indydog_stop();
				retval = 0;
			}

			if (options & WDIOS_ENABLECARD) {
				indydog_start();
				retval = 0;
			}

			return retval;
		}
	}
}

static int indydog_notify_sys(struct notifier_block *this, unsigned long code, void *unused)
{
	if (code == SYS_DOWN || code == SYS_HALT)
		indydog_stop();		/* Turn the WDT off */

	return NOTIFY_DONE;
}

static const struct file_operations indydog_fops = {
	.owner		= THIS_MODULE,
	.llseek		= no_llseek,
	.write		= indydog_write,
	.ioctl		= indydog_ioctl,
	.open		= indydog_open,
	.release	= indydog_release,
};

static struct miscdevice indydog_miscdev = {
	.minor		= WATCHDOG_MINOR,
	.name		= "watchdog",
	.fops		= &indydog_fops,
};

static struct notifier_block indydog_notifier = {
	.notifier_call = indydog_notify_sys,
};

static char banner[] __initdata =
	KERN_INFO PFX "Hardware Watchdog Timer for SGI IP22: 0.3\n";

static int __init watchdog_init(void)
{
	int ret;

	ret = register_reboot_notifier(&indydog_notifier);
	if (ret) {
		printk(KERN_ERR PFX "cannot register reboot notifier (err=%d)\n",
			ret);
		return ret;
	}

	ret = misc_register(&indydog_miscdev);
	if (ret) {
		printk(KERN_ERR PFX "cannot register miscdev on minor=%d (err=%d)\n",
			WATCHDOG_MINOR, ret);
		unregister_reboot_notifier(&indydog_notifier);
		return ret;
	}

	printk(banner);

	return 0;
}

static void __exit watchdog_exit(void)
{
	misc_deregister(&indydog_miscdev);
	unregister_reboot_notifier(&indydog_notifier);
}

module_init(watchdog_init);
module_exit(watchdog_exit);

MODULE_AUTHOR("Guido Guenther <agx@sigxcpu.org>");
MODULE_DESCRIPTION("Hardware Watchdog Device for SGI IP22");
MODULE_LICENSE("GPL");
MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR);
Commit	Line	Data
1da177e4 LT	1	/*
	2	* IndyDog 0.3 A Hardware Watchdog Device for SGI IP22
	3	*
	4	* (c) Copyright 2002 Guido Guenther <agx@sigxcpu.org>, All Rights Reserved.
	5	*
	6	* This program is free software; you can redistribute it and/or
	7	* modify it under the terms of the GNU General Public License
	8	* as published by the Free Software Foundation; either version
	9	* 2 of the License, or (at your option) any later version.
	10	*
	11	* based on softdog.c by Alan Cox <alan@redhat.com>
	12	*/
	13
	14	#include <linux/module.h>
	15	#include <linux/moduleparam.h>
1da177e4 LT	16	#include <linux/types.h>
	17	#include <linux/kernel.h>
	18	#include <linux/fs.h>
	19	#include <linux/mm.h>
	20	#include <linux/miscdevice.h>
	21	#include <linux/watchdog.h>
	22	#include <linux/notifier.h>
	23	#include <linux/reboot.h>
	24	#include <linux/init.h>
	25	#include <asm/uaccess.h>
	26	#include <asm/sgi/mc.h>
	27
	28	#define PFX "indydog: "
	29	static int indydog_alive;
	30
1da177e4 LT	31	#define WATCHDOG_TIMEOUT 30 /* 30 sec default timeout */
1da177e4 LT	32
4bfdf378	33	static int nowayout = WATCHDOG_NOWAYOUT;
1da177e4	34	module_param(nowayout, int, 0);
bffda5c8	35	MODULE_PARM_DESC(nowayout, "Watchdog cannot be stopped once started (default=" __MODULE_STRING(WATCHDOG_NOWAYOUT) ")");
1da177e4 LT	36
	37	static void indydog_start(void)
	38	{
	39	u32 mc_ctrl0 = sgimc->cpuctrl0;
	40
	41	mc_ctrl0 = sgimc->cpuctrl0 \| SGIMC_CCTRL0_WDOG;
	42	sgimc->cpuctrl0 = mc_ctrl0;
	43	}
	44
	45	static void indydog_stop(void)
	46	{
	47	u32 mc_ctrl0 = sgimc->cpuctrl0;
	48
	49	mc_ctrl0 &= ~SGIMC_CCTRL0_WDOG;
	50	sgimc->cpuctrl0 = mc_ctrl0;
	51
	52	printk(KERN_INFO PFX "Stopped watchdog timer.\n");
	53	}
	54
	55	static void indydog_ping(void)
	56	{
	57	sgimc->watchdogt = 0;
	58	}
	59
	60	/*
	61	* Allow only one person to hold it open
	62	*/
	63	static int indydog_open(struct inode inode, struct file file)
	64	{
	65	if (indydog_alive)
	66	return -EBUSY;
	67
	68	if (nowayout)
	69	__module_get(THIS_MODULE);
	70
	71	/* Activate timer */
	72	indydog_start();
	73	indydog_ping();
	74
	75	indydog_alive = 1;
	76	printk(KERN_INFO "Started watchdog timer.\n");
	77
	78	return nonseekable_open(inode, file);
	79	}
	80
	81	static int indydog_release(struct inode inode, struct file file)
	82	{
	83	/* Shut off the timer.
	84	* Lock it in if it's a module and we defined ...NOWAYOUT */
	85	if (!nowayout)
	86	indydog_stop(); /* Turn the WDT off */
	87
	88	indydog_alive = 0;
	89
	90	return 0;
	91	}
	92
	93	static ssize_t indydog_write(struct file file, const char data, size_t len, loff_t *ppos)
	94	{
	95	/* Refresh the timer. */
	96	if (len) {
	97	indydog_ping();
	98	}
	99	return len;
100	}
101
102	static int indydog_ioctl(struct inode inode, struct file file,
103	unsigned int cmd, unsigned long arg)
104	{
105	int options, retval = -EINVAL;
106	static struct watchdog_info ident = {
107	.options = WDIOF_KEEPALIVEPING \|
108	WDIOF_MAGICCLOSE,
109	.firmware_version = 0,
110	.identity = "Hardware Watchdog for SGI IP22",
111	};
112
113	switch (cmd) {
114	default:
795b89d2	115	return -ENOTTY;
1da177e4 LT	116	case WDIOC_GETSUPPORT:
	117	if (copy_to_user((struct watchdog_info *)arg,
	118	&ident, sizeof(ident)))
	119	return -EFAULT;
	120	return 0;
	121	case WDIOC_GETSTATUS:
	122	case WDIOC_GETBOOTSTATUS:
	123	return put_user(0,(int *)arg);
	124	case WDIOC_KEEPALIVE:
	125	indydog_ping();
	126	return 0;
	127	case WDIOC_GETTIMEOUT:
	128	return put_user(WATCHDOG_TIMEOUT,(int *)arg);
	129	case WDIOC_SETOPTIONS:
	130	{
	131	if (get_user(options, (int *)arg))
	132	return -EFAULT;
	133
	134	if (options & WDIOS_DISABLECARD) {
	135	indydog_stop();
	136	retval = 0;
	137	}
	138
	139	if (options & WDIOS_ENABLECARD) {
	140	indydog_start();
	141	retval = 0;
	142	}
	143
	144	return retval;
	145	}
	146	}
	147	}
	148
	149	static int indydog_notify_sys(struct notifier_block this, unsigned long code, void unused)
	150	{
	151	if (code == SYS_DOWN \|\| code == SYS_HALT)
	152	indydog_stop(); /* Turn the WDT off */
	153
	154	return NOTIFY_DONE;
	155	}
	156
62322d25	157	static const struct file_operations indydog_fops = {
1da177e4 LT	158	.owner = THIS_MODULE,
	159	.llseek = no_llseek,
	160	.write = indydog_write,
	161	.ioctl = indydog_ioctl,
	162	.open = indydog_open,
	163	.release = indydog_release,
	164	};
	165
	166	static struct miscdevice indydog_miscdev = {
	167	.minor = WATCHDOG_MINOR,
	168	.name = "watchdog",
	169	.fops = &indydog_fops,
	170	};
	171
	172	static struct notifier_block indydog_notifier = {
	173	.notifier_call = indydog_notify_sys,
	174	};
	175
	176	static char banner[] __initdata =
	177	KERN_INFO PFX "Hardware Watchdog Timer for SGI IP22: 0.3\n";
	178
	179	static int __init watchdog_init(void)
	180	{
	181	int ret;
	182
	183	ret = register_reboot_notifier(&indydog_notifier);
	184	if (ret) {
	185	printk(KERN_ERR PFX "cannot register reboot notifier (err=%d)\n",
	186	ret);
	187	return ret;
	188	}
	189
	190	ret = misc_register(&indydog_miscdev);
	191	if (ret) {
	192	printk(KERN_ERR PFX "cannot register miscdev on minor=%d (err=%d)\n",
	193	WATCHDOG_MINOR, ret);
	194	unregister_reboot_notifier(&indydog_notifier);
	195	return ret;
	196	}
	197
	198	printk(banner);
	199
	200	return 0;
	201	}
	202
	203	static void __exit watchdog_exit(void)
	204	{
	205	misc_deregister(&indydog_miscdev);
	206	unregister_reboot_notifier(&indydog_notifier);
	207	}
	208
	209	module_init(watchdog_init);
	210	module_exit(watchdog_exit);
	211
	212	MODULE_AUTHOR("Guido Guenther <agx@sigxcpu.org>");
	213	MODULE_DESCRIPTION("Hardware Watchdog Device for SGI IP22");
	214	MODULE_LICENSE("GPL");
	215	MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR);