[deliverable/linux.git] / drivers / char / watchdog / sbc8360.c

/*
 *	SBC8360 Watchdog driver
 *
 *	(c) Copyright 2005 Webcon, Inc.
 *
 *	Based on ib700wdt.c, which is based on advantechwdt.c which is based
 *      on acquirewdt.c which is based on wdt.c.
 *
 *	(c) Copyright 2001 Charles Howes <chowes@vsol.net>
 *
 *      Based on advantechwdt.c which is based on acquirewdt.c which
 *       is based on wdt.c.
 *
 *	(c) Copyright 2000-2001 Marek Michalkiewicz <marekm@linux.org.pl>
 *
 *	Based on acquirewdt.c which is based on wdt.c.
 *	Original copyright messages:
 *
 *	(c) Copyright 1996 Alan Cox <alan@redhat.com>, All Rights Reserved.
 *				http://www.redhat.com
 *
 *	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.
 *
 *	Neither Alan Cox nor CymruNet Ltd. admit liability nor provide
 *	warranty for any of this software. This material is provided
 *	"AS-IS" and at no charge.
 *
 *	(c) Copyright 1995    Alan Cox <alan@redhat.com>
 *
 *      14-Dec-2001 Matt Domsch <Matt_Domsch@dell.com>
 *           Added nowayout module option to override CONFIG_WATCHDOG_NOWAYOUT
 *           Added timeout module option to override default
 *
 */

#include <linux/config.h>
#include <linux/module.h>
#include <linux/types.h>
#include <linux/miscdevice.h>
#include <linux/watchdog.h>
#include <linux/ioport.h>
#include <linux/delay.h>
#include <linux/notifier.h>
#include <linux/fs.h>
#include <linux/reboot.h>
#include <linux/init.h>
#include <linux/spinlock.h>
#include <linux/moduleparam.h>

#include <asm/io.h>
#include <asm/uaccess.h>
#include <asm/system.h>

static unsigned long sbc8360_is_open;
static spinlock_t sbc8360_lock;
static char expect_close;

#define PFX "sbc8360: "

/*
 *
 * Watchdog Timer Configuration
 *
 * The function of the watchdog timer is to reset the system automatically
 * and is defined at I/O port 0120H and 0121H.  To enable the watchdog timer
 * and allow the system to reset, write appropriate values from the table
 * below to I/O port 0120H and 0121H.  To disable the timer, write a zero
 * value to I/O port 0121H for the system to stop the watchdog function.
 *
 * The following describes how the timer should be programmed (according to
 * the vendor documentation)
 *
 * Enabling Watchdog:
 * MOV AX,000AH (enable, phase I)
 * MOV DX,0120H
 * OUT DX,AX
 * MOV AX,000BH (enable, phase II)
 * MOV DX,0120H
 * OUT DX,AX
 * MOV AX,000nH (set multiplier n, from 1-4)
 * MOV DX,0120H
 * OUT DX,AX
 * MOV AX,000mH (set base timer m, from 0-F)
 * MOV DX,0121H
 * OUT DX,AX
 *
 * Reset timer:
 * MOV AX,000mH (same as set base timer, above)
 * MOV DX,0121H
 * OUT DX,AX
 *
 * Disabling Watchdog:
 * MOV AX,0000H (a zero value)
 * MOV DX,0120H
 * OUT DX,AX
 *
 * Watchdog timeout configuration values:
 *		N
 *	M |	1	2	3	4
 *	--|----------------------------------
 *	0 |	0.5s	5s	50s	100s
 *	1 |	1s	10s	100s	200s
 *	2 |	1.5s	15s	150s	300s
 *	3 |	2s	20s	200s	400s
 *	4 |	2.5s	25s	250s	500s
 *	5 |	3s	30s	300s	600s
 *	6 |	3.5s	35s	350s	700s
 *	7 |	4s	40s	400s	800s
 *	8 |	4.5s	45s	450s	900s
 *	9 |	5s	50s	500s	1000s
 *	A |	5.5s	55s	550s	1100s
 *	B |	6s	60s	600s	1200s
 *	C |	6.5s	65s	650s	1300s
 *	D |	7s	70s	700s	1400s
 *	E |	7.5s	75s	750s	1500s
 *	F |	8s	80s 	800s 	1600s
 *
 * Another way to say the same things is:
 *  For N=1, Timeout = (M+1) * 0.5s
 *  For N=2, Timeout = (M+1) * 5s
 *  For N=3, Timeout = (M+1) * 50s
 *  For N=4, Timeout = (M+1) * 100s
 *
 */

static int wd_times[64][2] = {
	{0, 1},			/* 0  = 0.5s */
	{1, 1},			/* 1  = 1s   */
	{2, 1},			/* 2  = 1.5s */
	{3, 1},			/* 3  = 2s   */
	{4, 1},			/* 4  = 2.5s */
	{5, 1},			/* 5  = 3s   */
	{6, 1},			/* 6  = 3.5s */
	{7, 1},			/* 7  = 4s   */
	{8, 1},			/* 8  = 4.5s */
	{9, 1},			/* 9  = 5s   */
	{0xA, 1},		/* 10 = 5.5s */
	{0xB, 1},		/* 11 = 6s   */
	{0xC, 1},		/* 12 = 6.5s */
	{0xD, 1},		/* 13 = 7s   */
	{0xE, 1},		/* 14 = 7.5s */
	{0xF, 1},		/* 15 = 8s   */
	{0, 2},			/* 16 = 5s  */
	{1, 2},			/* 17 = 10s */
	{2, 2},			/* 18 = 15s */
	{3, 2},			/* 19 = 20s */
	{4, 2},			/* 20 = 25s */
	{5, 2},			/* 21 = 30s */
	{6, 2},			/* 22 = 35s */
	{7, 2},			/* 23 = 40s */
	{8, 2},			/* 24 = 45s */
	{9, 2},			/* 25 = 50s */
	{0xA, 2},		/* 26 = 55s */
	{0xB, 2},		/* 27 = 60s */
	{0xC, 2},		/* 28 = 65s */
	{0xD, 2},		/* 29 = 70s */
	{0xE, 2},		/* 30 = 75s */
	{0xF, 2},		/* 31 = 80s */
	{0, 3},			/* 32 = 50s  */
	{1, 3},			/* 33 = 100s */
	{2, 3},			/* 34 = 150s */
	{3, 3},			/* 35 = 200s */
	{4, 3},			/* 36 = 250s */
	{5, 3},			/* 37 = 300s */
	{6, 3},			/* 38 = 350s */
	{7, 3},			/* 39 = 400s */
	{8, 3},			/* 40 = 450s */
	{9, 3},			/* 41 = 500s */
	{0xA, 3},		/* 42 = 550s */
	{0xB, 3},		/* 43 = 600s */
	{0xC, 3},		/* 44 = 650s */
	{0xD, 3},		/* 45 = 700s */
	{0xE, 3},		/* 46 = 750s */
	{0xF, 3},		/* 47 = 800s */
	{0, 4},			/* 48 = 100s */
	{1, 4},			/* 49 = 200s */
	{2, 4},			/* 50 = 300s */
	{3, 4},			/* 51 = 400s */
	{4, 4},			/* 52 = 500s */
	{5, 4},			/* 53 = 600s */
	{6, 4},			/* 54 = 700s */
	{7, 4},			/* 55 = 800s */
	{8, 4},			/* 56 = 900s */
	{9, 4},			/* 57 = 1000s */
	{0xA, 4},		/* 58 = 1100s */
	{0xB, 4},		/* 59 = 1200s */
	{0xC, 4},		/* 60 = 1300s */
	{0xD, 4},		/* 61 = 1400s */
	{0xE, 4},		/* 62 = 1500s */
	{0xF, 4}		/* 63 = 1600s */
};

#define SBC8360_ENABLE 0x120
#define SBC8360_BASETIME 0x121

static int timeout = 27;
static int wd_margin = 0xB;
static int wd_multiplier = 2;

#ifdef CONFIG_WATCHDOG_NOWAYOUT
static int nowayout = 1;
#else
static int nowayout = 0;
#endif

module_param(timeout, int, 27);
MODULE_PARM_DESC(timeout, "Index into timeout table (0-63) (default=27 (60s))");
module_param(nowayout, int, 0);
MODULE_PARM_DESC(nowayout,
		 "Watchdog cannot be stopped once started (default=CONFIG_WATCHDOG_NOWAYOUT)");

/*
 *	Kernel methods.
 */

/* Activate and pre-configure watchdog */
static void sbc8360_activate(void)
{
	/* Enable the watchdog */
	outb(0x0A, SBC8360_ENABLE);
	msleep_interruptible(100);
	outb(0x0B, SBC8360_ENABLE);
	msleep_interruptible(100);
	/* Set timeout multiplier */
	outb(wd_multiplier, SBC8360_ENABLE);
	msleep_interruptible(100);
	/* Nothing happens until first sbc8360_ping() */
}

/* Kernel pings watchdog */
static void sbc8360_ping(void)
{
	/* Write the base timer register */
	outb(wd_margin, SBC8360_BASETIME);
}

/* Userspace pings kernel driver, or requests clean close */
static ssize_t sbc8360_write(struct file *file, const char __user * buf,
			     size_t count, loff_t * ppos)
{
	if (count) {
		if (!nowayout) {
			size_t i;

			/* In case it was set long ago */
			expect_close = 0;

			for (i = 0; i != count; i++) {
				char c;
				if (get_user(c, buf + i))
					return -EFAULT;
				if (c == 'V')
					expect_close = 42;
			}
		}
		sbc8360_ping();
	}
	return count;
}

static int sbc8360_open(struct inode *inode, struct file *file)
{
	spin_lock(&sbc8360_lock);
	if (test_and_set_bit(0, &sbc8360_is_open)) {
		spin_unlock(&sbc8360_lock);
		return -EBUSY;
	}
	if (nowayout)
		__module_get(THIS_MODULE);

	/* Activate and ping once to start the countdown */
	spin_unlock(&sbc8360_lock);
	sbc8360_activate();
	sbc8360_ping();
	return nonseekable_open(inode, file);
}

static int sbc8360_close(struct inode *inode, struct file *file)
{
	spin_lock(&sbc8360_lock);
	if (expect_close == 42)
		outb(0, SBC8360_ENABLE);
	else
		printk(KERN_CRIT PFX
		       "SBC8360 device closed unexpectedly.  SBC8360 will not stop!\n");

	clear_bit(0, &sbc8360_is_open);
	expect_close = 0;
	spin_unlock(&sbc8360_lock);
	return 0;
}

/*
 *	Notifier for system down
 */

static int sbc8360_notify_sys(struct notifier_block *this, unsigned long code,
			      void *unused)
{
	if (code == SYS_DOWN || code == SYS_HALT) {
		/* Disable the SBC8360 Watchdog */
		outb(0, SBC8360_ENABLE);
	}
	return NOTIFY_DONE;
}

/*
 *	Kernel Interfaces
 */

static struct file_operations sbc8360_fops = {
	.owner = THIS_MODULE,
	.llseek = no_llseek,
	.write = sbc8360_write,
	.open = sbc8360_open,
	.release = sbc8360_close,
};

static struct miscdevice sbc8360_miscdev = {
	.minor = WATCHDOG_MINOR,
	.name = "watchdog",
	.fops = &sbc8360_fops,
};

/*
 *	The SBC8360 needs to learn about soft shutdowns in order to
 *	turn the timebomb registers off.
 */

static struct notifier_block sbc8360_notifier = {
	.notifier_call = sbc8360_notify_sys,
};

static int __init sbc8360_init(void)
{
	int res;
	unsigned long int mseconds = 60000;

	spin_lock_init(&sbc8360_lock);
	res = misc_register(&sbc8360_miscdev);
	if (res) {
		printk(KERN_ERR PFX "failed to register misc device\n");
		goto out_nomisc;
	}

	if (!request_region(SBC8360_ENABLE, 1, "SBC8360")) {
		printk(KERN_ERR PFX "ENABLE method I/O %X is not available.\n",
		       SBC8360_ENABLE);
		res = -EIO;
		goto out_noenablereg;
	}
	if (!request_region(SBC8360_BASETIME, 1, "SBC8360")) {
		printk(KERN_ERR PFX
		       "BASETIME method I/O %X is not available.\n",
		       SBC8360_BASETIME);
		res = -EIO;
		goto out_nobasetimereg;
	}

	res = register_reboot_notifier(&sbc8360_notifier);
	if (res) {
		printk(KERN_ERR PFX "Failed to register reboot notifier.\n");
		goto out_noreboot;
	}

	if (timeout < 0 || timeout > 63) {
		printk(KERN_ERR PFX "Invalid timeout index (must be 0-63).\n");
		res = -EINVAL;
		goto out_noreboot;
	}

	wd_margin = wd_times[timeout][0];
	wd_multiplier = wd_times[timeout][1];

	if (wd_multiplier == 1)
		mseconds = (wd_margin + 1) * 500;
	else if (wd_multiplier == 2)
		mseconds = (wd_margin + 1) * 5000;
	else if (wd_multiplier == 3)
		mseconds = (wd_margin + 1) * 50000;
	else if (wd_multiplier == 4)
		mseconds = (wd_margin + 1) * 100000;

	/* My kingdom for the ability to print "0.5 seconds" in the kernel! */
	printk(KERN_INFO PFX "Timeout set at %ld ms.\n", mseconds);

	return 0;

      out_noreboot:
	release_region(SBC8360_ENABLE, 1);
	release_region(SBC8360_BASETIME, 1);
      out_noenablereg:
      out_nobasetimereg:
	misc_deregister(&sbc8360_miscdev);
      out_nomisc:
	return res;
}

static void __exit sbc8360_exit(void)
{
	misc_deregister(&sbc8360_miscdev);
	unregister_reboot_notifier(&sbc8360_notifier);
	release_region(SBC8360_ENABLE, 1);
	release_region(SBC8360_BASETIME, 1);
}

module_init(sbc8360_init);
module_exit(sbc8360_exit);

MODULE_AUTHOR("Ian E. Morgan <imorgan@webcon.ca>");
MODULE_DESCRIPTION("SBC8360 watchdog driver");
MODULE_LICENSE("GPL");
MODULE_VERSION("1.0");
MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR);

/* end of sbc8360.c */
Commit	Line	Data
3809ad38 IM	1	/*
	2	* SBC8360 Watchdog driver
	3	*
	4	* (c) Copyright 2005 Webcon, Inc.
	5	*
	6	* Based on ib700wdt.c, which is based on advantechwdt.c which is based
	7	* on acquirewdt.c which is based on wdt.c.
	8	*
	9	* (c) Copyright 2001 Charles Howes <chowes@vsol.net>
	10	*
	11	* Based on advantechwdt.c which is based on acquirewdt.c which
	12	* is based on wdt.c.
	13	*
	14	* (c) Copyright 2000-2001 Marek Michalkiewicz <marekm@linux.org.pl>
	15	*
	16	* Based on acquirewdt.c which is based on wdt.c.
	17	* Original copyright messages:
	18	*
	19	* (c) Copyright 1996 Alan Cox <alan@redhat.com>, All Rights Reserved.
	20	* http://www.redhat.com
	21	*
	22	* This program is free software; you can redistribute it and/or
	23	* modify it under the terms of the GNU General Public License
	24	* as published by the Free Software Foundation; either version
	25	* 2 of the License, or (at your option) any later version.
	26	*
	27	* Neither Alan Cox nor CymruNet Ltd. admit liability nor provide
	28	* warranty for any of this software. This material is provided
	29	* "AS-IS" and at no charge.
	30	*
	31	* (c) Copyright 1995 Alan Cox <alan@redhat.com>
	32	*
	33	* 14-Dec-2001 Matt Domsch <Matt_Domsch@dell.com>
	34	* Added nowayout module option to override CONFIG_WATCHDOG_NOWAYOUT
	35	* Added timeout module option to override default
	36	*
	37	*/
	38
	39	#include <linux/config.h>
	40	#include <linux/module.h>
	41	#include <linux/types.h>
	42	#include <linux/miscdevice.h>
	43	#include <linux/watchdog.h>
	44	#include <linux/ioport.h>
	45	#include <linux/delay.h>
	46	#include <linux/notifier.h>
	47	#include <linux/fs.h>
	48	#include <linux/reboot.h>
	49	#include <linux/init.h>
	50	#include <linux/spinlock.h>
	51	#include <linux/moduleparam.h>
	52
	53	#include <asm/io.h>
	54	#include <asm/uaccess.h>
	55	#include <asm/system.h>
	56
	57	static unsigned long sbc8360_is_open;
	58	static spinlock_t sbc8360_lock;
	59	static char expect_close;
	60
	61	#define PFX "sbc8360: "
	62
	63	/*
	64	*
65	* Watchdog Timer Configuration
66	*
67	* The function of the watchdog timer is to reset the system automatically
68	* and is defined at I/O port 0120H and 0121H. To enable the watchdog timer
69	* and allow the system to reset, write appropriate values from the table
70	* below to I/O port 0120H and 0121H. To disable the timer, write a zero
71	* value to I/O port 0121H for the system to stop the watchdog function.
72	*
73	* The following describes how the timer should be programmed (according to
74	* the vendor documentation)
75	*
76	* Enabling Watchdog:
77	* MOV AX,000AH (enable, phase I)
78	* MOV DX,0120H
79	* OUT DX,AX
80	* MOV AX,000BH (enable, phase II)
81	* MOV DX,0120H
82	* OUT DX,AX
83	* MOV AX,000nH (set multiplier n, from 1-4)
84	* MOV DX,0120H
85	* OUT DX,AX
86	* MOV AX,000mH (set base timer m, from 0-F)
87	* MOV DX,0121H
88	* OUT DX,AX
89	*
90	* Reset timer:
91	* MOV AX,000mH (same as set base timer, above)
92	* MOV DX,0121H
93	* OUT DX,AX
94	*
95	* Disabling Watchdog:
96	* MOV AX,0000H (a zero value)
97	* MOV DX,0120H
98	* OUT DX,AX
99	*
100	* Watchdog timeout configuration values:
101	* N
102	* M \| 1 2 3 4
103	* --\|----------------------------------
104	* 0 \| 0.5s 5s 50s 100s
105	* 1 \| 1s 10s 100s 200s
106	* 2 \| 1.5s 15s 150s 300s
107	* 3 \| 2s 20s 200s 400s
108	* 4 \| 2.5s 25s 250s 500s
109	* 5 \| 3s 30s 300s 600s
110	* 6 \| 3.5s 35s 350s 700s
111	* 7 \| 4s 40s 400s 800s
112	* 8 \| 4.5s 45s 450s 900s
113	* 9 \| 5s 50s 500s 1000s
114	* A \| 5.5s 55s 550s 1100s
115	* B \| 6s 60s 600s 1200s
116	* C \| 6.5s 65s 650s 1300s
117	* D \| 7s 70s 700s 1400s
118	* E \| 7.5s 75s 750s 1500s
119	* F \| 8s 80s 800s 1600s
120	*
121	* Another way to say the same things is:
122	* For N=1, Timeout = (M+1) * 0.5s
123	* For N=2, Timeout = (M+1) * 5s
124	* For N=3, Timeout = (M+1) * 50s
125	* For N=4, Timeout = (M+1) * 100s
126	*
127	*/
128
129	static int wd_times[64][2] = {
130	{0, 1}, /* 0 = 0.5s */
131	{1, 1}, /* 1 = 1s */
132	{2, 1}, /* 2 = 1.5s */
133	{3, 1}, /* 3 = 2s */
134	{4, 1}, /* 4 = 2.5s */
135	{5, 1}, /* 5 = 3s */
136	{6, 1}, /* 6 = 3.5s */
137	{7, 1}, /* 7 = 4s */
138	{8, 1}, /* 8 = 4.5s */
139	{9, 1}, /* 9 = 5s */
140	{0xA, 1}, /* 10 = 5.5s */
141	{0xB, 1}, /* 11 = 6s */
142	{0xC, 1}, /* 12 = 6.5s */
143	{0xD, 1}, /* 13 = 7s */
144	{0xE, 1}, /* 14 = 7.5s */
145	{0xF, 1}, /* 15 = 8s */
146	{0, 2}, /* 16 = 5s */
147	{1, 2}, /* 17 = 10s */
148	{2, 2}, /* 18 = 15s */
149	{3, 2}, /* 19 = 20s */
150	{4, 2}, /* 20 = 25s */
151	{5, 2}, /* 21 = 30s */
152	{6, 2}, /* 22 = 35s */
153	{7, 2}, /* 23 = 40s */
154	{8, 2}, /* 24 = 45s */
155	{9, 2}, /* 25 = 50s */
156	{0xA, 2}, /* 26 = 55s */
157	{0xB, 2}, /* 27 = 60s */
158	{0xC, 2}, /* 28 = 65s */
159	{0xD, 2}, /* 29 = 70s */
160	{0xE, 2}, /* 30 = 75s */
161	{0xF, 2}, /* 31 = 80s */
162	{0, 3}, /* 32 = 50s */
163	{1, 3}, /* 33 = 100s */
164	{2, 3}, /* 34 = 150s */
165	{3, 3}, /* 35 = 200s */
166	{4, 3}, /* 36 = 250s */
167	{5, 3}, /* 37 = 300s */
168	{6, 3}, /* 38 = 350s */
169	{7, 3}, /* 39 = 400s */
170	{8, 3}, /* 40 = 450s */
171	{9, 3}, /* 41 = 500s */
172	{0xA, 3}, /* 42 = 550s */
173	{0xB, 3}, /* 43 = 600s */
174	{0xC, 3}, /* 44 = 650s */
175	{0xD, 3}, /* 45 = 700s */
176	{0xE, 3}, /* 46 = 750s */
177	{0xF, 3}, /* 47 = 800s */
178	{0, 4}, /* 48 = 100s */
179	{1, 4}, /* 49 = 200s */
180	{2, 4}, /* 50 = 300s */
181	{3, 4}, /* 51 = 400s */
182	{4, 4}, /* 52 = 500s */
183	{5, 4}, /* 53 = 600s */
184	{6, 4}, /* 54 = 700s */
185	{7, 4}, /* 55 = 800s */
186	{8, 4}, /* 56 = 900s */
187	{9, 4}, /* 57 = 1000s */
188	{0xA, 4}, /* 58 = 1100s */
189	{0xB, 4}, /* 59 = 1200s */
190	{0xC, 4}, /* 60 = 1300s */
191	{0xD, 4}, /* 61 = 1400s */
192	{0xE, 4}, /* 62 = 1500s */
193	{0xF, 4} /* 63 = 1600s */
194	};
195
196	#define SBC8360_ENABLE 0x120
197	#define SBC8360_BASETIME 0x121
198
199	static int timeout = 27;
200	static int wd_margin = 0xB;
201	static int wd_multiplier = 2;
202
203	#ifdef CONFIG_WATCHDOG_NOWAYOUT
204	static int nowayout = 1;
205	#else
206	static int nowayout = 0;
207	#endif
208
209	module_param(timeout, int, 27);
210	MODULE_PARM_DESC(timeout, "Index into timeout table (0-63) (default=27 (60s))");
211	module_param(nowayout, int, 0);
212	MODULE_PARM_DESC(nowayout,
213	"Watchdog cannot be stopped once started (default=CONFIG_WATCHDOG_NOWAYOUT)");
214
215	/*
216	* Kernel methods.
217	*/
218
219	/* Activate and pre-configure watchdog */
220	static void sbc8360_activate(void)
221	{
222	/* Enable the watchdog */
223	outb(0x0A, SBC8360_ENABLE);
224	msleep_interruptible(100);
225	outb(0x0B, SBC8360_ENABLE);
226	msleep_interruptible(100);
227	/* Set timeout multiplier */
228	outb(wd_multiplier, SBC8360_ENABLE);
229	msleep_interruptible(100);
230	/* Nothing happens until first sbc8360_ping() */
231	}
232
233	/* Kernel pings watchdog */
234	static void sbc8360_ping(void)
235	{
236	/* Write the base timer register */
237	outb(wd_margin, SBC8360_BASETIME);
238	}
239
240	/* Userspace pings kernel driver, or requests clean close */
241	static ssize_t sbc8360_write(struct file file, const char __user buf,
242	size_t count, loff_t * ppos)
243	{
244	if (count) {
245	if (!nowayout) {
246	size_t i;
247
248	/* In case it was set long ago */
249	expect_close = 0;
250
251	for (i = 0; i != count; i++) {
252	char c;
253	if (get_user(c, buf + i))
254	return -EFAULT;
255	if (c == 'V')
256	expect_close = 42;
257	}
258	}
259	sbc8360_ping();
260	}
261	return count;
262	}
263
264	static int sbc8360_open(struct inode inode, struct file file)
265	{
266	spin_lock(&sbc8360_lock);
267	if (test_and_set_bit(0, &sbc8360_is_open)) {
268	spin_unlock(&sbc8360_lock);
269	return -EBUSY;
270	}
271	if (nowayout)
272	__module_get(THIS_MODULE);
273
274	/* Activate and ping once to start the countdown */
275	spin_unlock(&sbc8360_lock);
276	sbc8360_activate();
277	sbc8360_ping();
278	return nonseekable_open(inode, file);
279	}
280
281	static int sbc8360_close(struct inode inode, struct file file)
282	{
283	spin_lock(&sbc8360_lock);
284	if (expect_close == 42)
285	outb(0, SBC8360_ENABLE);
286	else
287	printk(KERN_CRIT PFX
288	"SBC8360 device closed unexpectedly. SBC8360 will not stop!\n");
289
290	clear_bit(0, &sbc8360_is_open);
291	expect_close = 0;
292	spin_unlock(&sbc8360_lock);
293	return 0;
294	}
295
296	/*
297	* Notifier for system down
298	*/
299
300	static int sbc8360_notify_sys(struct notifier_block *this, unsigned long code,
301	void *unused)
302	{
303	if (code == SYS_DOWN \|\| code == SYS_HALT) {
304	/* Disable the SBC8360 Watchdog */
305	outb(0, SBC8360_ENABLE);
306	}
307	return NOTIFY_DONE;
308	}
309
310	/*
311	* Kernel Interfaces
312	*/
313
314	static struct file_operations sbc8360_fops = {
315	.owner = THIS_MODULE,
316	.llseek = no_llseek,
317	.write = sbc8360_write,
318	.open = sbc8360_open,
319	.release = sbc8360_close,
320	};
321
322	static struct miscdevice sbc8360_miscdev = {
323	.minor = WATCHDOG_MINOR,
324	.name = "watchdog",
325	.fops = &sbc8360_fops,
326	};
327
328	/*
329	* The SBC8360 needs to learn about soft shutdowns in order to
330	* turn the timebomb registers off.
331	*/
332
333	static struct notifier_block sbc8360_notifier = {
334	.notifier_call = sbc8360_notify_sys,
335	};
336
337	static int __init sbc8360_init(void)
338	{
339	int res;
340	unsigned long int mseconds = 60000;
341
342	spin_lock_init(&sbc8360_lock);
343	res = misc_register(&sbc8360_miscdev);
344	if (res) {
345	printk(KERN_ERR PFX "failed to register misc device\n");
346	goto out_nomisc;
347	}
348
349	if (!request_region(SBC8360_ENABLE, 1, "SBC8360")) {
350	printk(KERN_ERR PFX "ENABLE method I/O %X is not available.\n",
351	SBC8360_ENABLE);
352	res = -EIO;
353	goto out_noenablereg;
354	}
355	if (!request_region(SBC8360_BASETIME, 1, "SBC8360")) {
356	printk(KERN_ERR PFX
357	"BASETIME method I/O %X is not available.\n",
358	SBC8360_BASETIME);
359	res = -EIO;
360	goto out_nobasetimereg;
361	}
362
363	res = register_reboot_notifier(&sbc8360_notifier);
364	if (res) {
365	printk(KERN_ERR PFX "Failed to register reboot notifier.\n");
366	goto out_noreboot;
367	}
368
369	if (timeout < 0 \|\| timeout > 63) {
370	printk(KERN_ERR PFX "Invalid timeout index (must be 0-63).\n");
371	res = -EINVAL;
372	goto out_noreboot;
373	}
374
375	wd_margin = wd_times[timeout][0];
376	wd_multiplier = wd_times[timeout][1];
377
378	if (wd_multiplier == 1)
379	mseconds = (wd_margin + 1) * 500;
380	else if (wd_multiplier == 2)
381	mseconds = (wd_margin + 1) * 5000;
382	else if (wd_multiplier == 3)
383	mseconds = (wd_margin + 1) * 50000;
384	else if (wd_multiplier == 4)
385	mseconds = (wd_margin + 1) * 100000;
386
387	/* My kingdom for the ability to print "0.5 seconds" in the kernel! */
388	printk(KERN_INFO PFX "Timeout set at %ld ms.\n", mseconds);
389
390	return 0;
391
392	out_noreboot:
393	release_region(SBC8360_ENABLE, 1);
394	release_region(SBC8360_BASETIME, 1);
395	out_noenablereg:
396	out_nobasetimereg:
397	misc_deregister(&sbc8360_miscdev);
398	out_nomisc:
399	return res;
400	}
401
402	static void __exit sbc8360_exit(void)
403	{
404	misc_deregister(&sbc8360_miscdev);
405	unregister_reboot_notifier(&sbc8360_notifier);
406	release_region(SBC8360_ENABLE, 1);
407	release_region(SBC8360_BASETIME, 1);
408	}
409
410	module_init(sbc8360_init);
411	module_exit(sbc8360_exit);
412
413	MODULE_AUTHOR("Ian E. Morgan <imorgan@webcon.ca>");
414	MODULE_DESCRIPTION("SBC8360 watchdog driver");
415	MODULE_LICENSE("GPL");
416	MODULE_VERSION("1.0");
417	MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR);
418
419	/* end of sbc8360.c */