[deliverable/linux.git] / drivers / 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@lxorguk.ukuu.org.uk>,
 *						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.
 *
 *	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@lxorguk.ukuu.org.uk>
 *
 *	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
 *
 */

#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt

#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 <linux/io.h>
#include <linux/uaccess.h>

#include <asm/system.h>

static unsigned long sbc8360_is_open;
static char expect_close;

/*
 *
 * 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;
static int nowayout = WATCHDOG_NOWAYOUT;

module_param(timeout, int, 0);
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="
				__MODULE_STRING(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);
}

/* stop watchdog */
static void sbc8360_stop(void)
{
	/* De-activate the watchdog */
	outb(0, SBC8360_ENABLE);
}

/* 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)
{
	if (test_and_set_bit(0, &sbc8360_is_open))
		return -EBUSY;
	if (nowayout)
		__module_get(THIS_MODULE);

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

static int sbc8360_close(struct inode *inode, struct file *file)
{
	if (expect_close == 42)
		sbc8360_stop();
	else
		pr_crit("SBC8360 device closed unexpectedly.  SBC8360 will not stop!\n");

	clear_bit(0, &sbc8360_is_open);
	expect_close = 0;
	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)
		sbc8360_stop();	/* Disable the SBC8360 Watchdog */

	return NOTIFY_DONE;
}

/*
 *	Kernel Interfaces
 */

static const 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;

	if (timeout < 0 || timeout > 63) {
		pr_err("Invalid timeout index (must be 0-63)\n");
		res = -EINVAL;
		goto out;
	}

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

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

	res = misc_register(&sbc8360_miscdev);
	if (res) {
		pr_err("failed to register misc device\n");
		goto out_nomisc;
	}

	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! */
	pr_info("Timeout set at %ld ms\n", mseconds);

	return 0;

out_nomisc:
	unregister_reboot_notifier(&sbc8360_notifier);
out_noreboot:
	release_region(SBC8360_BASETIME, 1);
out_nobasetimereg:
	release_region(SBC8360_ENABLE, 1);
out:
	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("1.01");
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
143a2e54	7	* on acquirewdt.c which is based on wdt.c.
3809ad38 IM	8	*
	9	* (c) Copyright 2001 Charles Howes <chowes@vsol.net>
	10	*
143a2e54 WVS	11	* Based on advantechwdt.c which is based on acquirewdt.c which
143a2e54 WVS	12	* is based on wdt.c.
3809ad38 IM	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	*
29fa0586 AC	19	* (c) Copyright 1996 Alan Cox <alan@lxorguk.ukuu.org.uk>,
29fa0586 AC	20	* All Rights Reserved.
3809ad38 IM	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	*
29fa0586	31	* (c) Copyright 1995 Alan Cox <alan@lxorguk.ukuu.org.uk>
3809ad38	32	*
143a2e54 WVS	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
3809ad38 IM	36	*
	37	*/
	38
27c766aa JP	39	#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
27c766aa JP	40
3809ad38 IM	41	#include <linux/module.h>
	42	#include <linux/types.h>
	43	#include <linux/miscdevice.h>
	44	#include <linux/watchdog.h>
	45	#include <linux/ioport.h>
	46	#include <linux/delay.h>
	47	#include <linux/notifier.h>
	48	#include <linux/fs.h>
	49	#include <linux/reboot.h>
	50	#include <linux/init.h>
	51	#include <linux/spinlock.h>
	52	#include <linux/moduleparam.h>
9f53c8de AC	53	#include <linux/io.h>
9f53c8de AC	54	#include <linux/uaccess.h>
3809ad38	55
3809ad38 IM	56	#include <asm/system.h>
	57
	58	static unsigned long sbc8360_is_open;
3809ad38 IM	59	static char expect_close;
3809ad38 IM	60
3809ad38 IM	61	/*
	62	*
	63	* Watchdog Timer Configuration
	64	*
	65	* The function of the watchdog timer is to reset the system automatically
	66	* and is defined at I/O port 0120H and 0121H. To enable the watchdog timer
	67	* and allow the system to reset, write appropriate values from the table
	68	* below to I/O port 0120H and 0121H. To disable the timer, write a zero
	69	* value to I/O port 0121H for the system to stop the watchdog function.
	70	*
	71	* The following describes how the timer should be programmed (according to
	72	* the vendor documentation)
	73	*
	74	* Enabling Watchdog:
	75	* MOV AX,000AH (enable, phase I)
	76	* MOV DX,0120H
	77	* OUT DX,AX
	78	* MOV AX,000BH (enable, phase II)
	79	* MOV DX,0120H
	80	* OUT DX,AX
	81	* MOV AX,000nH (set multiplier n, from 1-4)
	82	* MOV DX,0120H
	83	* OUT DX,AX
	84	* MOV AX,000mH (set base timer m, from 0-F)
	85	* MOV DX,0121H
	86	* OUT DX,AX
	87	*
	88	* Reset timer:
	89	* MOV AX,000mH (same as set base timer, above)
	90	* MOV DX,0121H
	91	* OUT DX,AX
	92	*
	93	* Disabling Watchdog:
	94	* MOV AX,0000H (a zero value)
	95	* MOV DX,0120H
	96	* OUT DX,AX
	97	*
	98	* Watchdog timeout configuration values:
	99	* N
	100	* M \| 1 2 3 4
	101	* --\|----------------------------------
	102	* 0 \| 0.5s 5s 50s 100s
	103	* 1 \| 1s 10s 100s 200s
	104	* 2 \| 1.5s 15s 150s 300s
	105	* 3 \| 2s 20s 200s 400s
	106	* 4 \| 2.5s 25s 250s 500s
	107	* 5 \| 3s 30s 300s 600s
	108	* 6 \| 3.5s 35s 350s 700s
	109	* 7 \| 4s 40s 400s 800s
	110	* 8 \| 4.5s 45s 450s 900s
	111	* 9 \| 5s 50s 500s 1000s
	112	* A \| 5.5s 55s 550s 1100s
	113	* B \| 6s 60s 600s 1200s
	114	* C \| 6.5s 65s 650s 1300s
	115	* D \| 7s 70s 700s 1400s
	116	* E \| 7.5s 75s 750s 1500s
5f3b2756	117	* F \| 8s 80s 800s 1600s
3809ad38 IM	118	*
	119	* Another way to say the same things is:
	120	* For N=1, Timeout = (M+1) * 0.5s
	121	* For N=2, Timeout = (M+1) * 5s
	122	* For N=3, Timeout = (M+1) * 50s
	123	* For N=4, Timeout = (M+1) * 100s
	124	*
	125	*/
	126
	127	static int wd_times[64][2] = {
	128	{0, 1}, /* 0 = 0.5s */
	129	{1, 1}, /* 1 = 1s */
	130	{2, 1}, /* 2 = 1.5s */
	131	{3, 1}, /* 3 = 2s */
	132	{4, 1}, /* 4 = 2.5s */
	133	{5, 1}, /* 5 = 3s */
	134	{6, 1}, /* 6 = 3.5s */
	135	{7, 1}, /* 7 = 4s */
	136	{8, 1}, /* 8 = 4.5s */
	137	{9, 1}, /* 9 = 5s */
	138	{0xA, 1}, /* 10 = 5.5s */
	139	{0xB, 1}, /* 11 = 6s */
	140	{0xC, 1}, /* 12 = 6.5s */
	141	{0xD, 1}, /* 13 = 7s */
	142	{0xE, 1}, /* 14 = 7.5s */
	143	{0xF, 1}, /* 15 = 8s */
	144	{0, 2}, /* 16 = 5s */
	145	{1, 2}, /* 17 = 10s */
	146	{2, 2}, /* 18 = 15s */
	147	{3, 2}, /* 19 = 20s */
	148	{4, 2}, /* 20 = 25s */
	149	{5, 2}, /* 21 = 30s */
	150	{6, 2}, /* 22 = 35s */
	151	{7, 2}, /* 23 = 40s */
	152	{8, 2}, /* 24 = 45s */
	153	{9, 2}, /* 25 = 50s */
	154	{0xA, 2}, /* 26 = 55s */
	155	{0xB, 2}, /* 27 = 60s */
	156	{0xC, 2}, /* 28 = 65s */
	157	{0xD, 2}, /* 29 = 70s */
	158	{0xE, 2}, /* 30 = 75s */
	159	{0xF, 2}, /* 31 = 80s */
	160	{0, 3}, /* 32 = 50s */
	161	{1, 3}, /* 33 = 100s */
	162	{2, 3}, /* 34 = 150s */
	163	{3, 3}, /* 35 = 200s */
	164	{4, 3}, /* 36 = 250s */
	165	{5, 3}, /* 37 = 300s */
	166	{6, 3}, /* 38 = 350s */
	167	{7, 3}, /* 39 = 400s */
	168	{8, 3}, /* 40 = 450s */
	169	{9, 3}, /* 41 = 500s */
	170	{0xA, 3}, /* 42 = 550s */
	171	{0xB, 3}, /* 43 = 600s */
	172	{0xC, 3}, /* 44 = 650s */
	173	{0xD, 3}, /* 45 = 700s */
	174	{0xE, 3}, /* 46 = 750s */
	175	{0xF, 3}, /* 47 = 800s */
	176	{0, 4}, /* 48 = 100s */
	177	{1, 4}, /* 49 = 200s */
	178	{2, 4}, /* 50 = 300s */
	179	{3, 4}, /* 51 = 400s */
	180	{4, 4}, /* 52 = 500s */
	181	{5, 4}, /* 53 = 600s */
182	{6, 4}, /* 54 = 700s */
183	{7, 4}, /* 55 = 800s */
184	{8, 4}, /* 56 = 900s */
185	{9, 4}, /* 57 = 1000s */
186	{0xA, 4}, /* 58 = 1100s */
187	{0xB, 4}, /* 59 = 1200s */
188	{0xC, 4}, /* 60 = 1300s */
189	{0xD, 4}, /* 61 = 1400s */
190	{0xE, 4}, /* 62 = 1500s */
191	{0xF, 4} /* 63 = 1600s */
192	};
193
194	#define SBC8360_ENABLE 0x120
195	#define SBC8360_BASETIME 0x121
196
197	static int timeout = 27;
198	static int wd_margin = 0xB;
199	static int wd_multiplier = 2;
3908bb18	200	static int nowayout = WATCHDOG_NOWAYOUT;
3809ad38	201
290995fc	202	module_param(timeout, int, 0);
3809ad38 IM	203	MODULE_PARM_DESC(timeout, "Index into timeout table (0-63) (default=27 (60s))");
	204	module_param(nowayout, int, 0);
	205	MODULE_PARM_DESC(nowayout,
9f53c8de AC	206	"Watchdog cannot be stopped once started (default="
9f53c8de AC	207	__MODULE_STRING(WATCHDOG_NOWAYOUT) ")");
3809ad38 IM	208
	209	/*
	210	* Kernel methods.
	211	*/
	212
	213	/* Activate and pre-configure watchdog */
	214	static void sbc8360_activate(void)
	215	{
	216	/* Enable the watchdog */
	217	outb(0x0A, SBC8360_ENABLE);
	218	msleep_interruptible(100);
	219	outb(0x0B, SBC8360_ENABLE);
	220	msleep_interruptible(100);
	221	/* Set timeout multiplier */
	222	outb(wd_multiplier, SBC8360_ENABLE);
	223	msleep_interruptible(100);
	224	/* Nothing happens until first sbc8360_ping() */
	225	}
	226
	227	/* Kernel pings watchdog */
	228	static void sbc8360_ping(void)
	229	{
	230	/* Write the base timer register */
	231	outb(wd_margin, SBC8360_BASETIME);
	232	}
	233
12b7a152 WVS	234	/* stop watchdog */
	235	static void sbc8360_stop(void)
	236	{
	237	/* De-activate the watchdog */
	238	outb(0, SBC8360_ENABLE);
	239	}
	240
3809ad38	241	/* Userspace pings kernel driver, or requests clean close */
9f53c8de AC	242	static ssize_t sbc8360_write(struct file file, const char __user buf,
9f53c8de AC	243	size_t count, loff_t *ppos)
3809ad38 IM	244	{
	245	if (count) {
	246	if (!nowayout) {
	247	size_t i;
	248
	249	/* In case it was set long ago */
	250	expect_close = 0;
	251
	252	for (i = 0; i != count; i++) {
	253	char c;
	254	if (get_user(c, buf + i))
	255	return -EFAULT;
	256	if (c == 'V')
	257	expect_close = 42;
	258	}
	259	}
	260	sbc8360_ping();
	261	}
	262	return count;
	263	}
	264
	265	static int sbc8360_open(struct inode inode, struct file file)
	266	{
9f53c8de	267	if (test_and_set_bit(0, &sbc8360_is_open))
3809ad38	268	return -EBUSY;
3809ad38 IM	269	if (nowayout)
	270	__module_get(THIS_MODULE);
	271
	272	/* Activate and ping once to start the countdown */
3809ad38 IM	273	sbc8360_activate();
	274	sbc8360_ping();
	275	return nonseekable_open(inode, file);
	276	}
	277
	278	static int sbc8360_close(struct inode inode, struct file file)
	279	{
3809ad38	280	if (expect_close == 42)
12b7a152	281	sbc8360_stop();
3809ad38	282	else
27c766aa	283	pr_crit("SBC8360 device closed unexpectedly. SBC8360 will not stop!\n");
3809ad38 IM	284
	285	clear_bit(0, &sbc8360_is_open);
	286	expect_close = 0;
3809ad38 IM	287	return 0;
	288	}
	289
	290	/*
	291	* Notifier for system down
	292	*/
	293
	294	static int sbc8360_notify_sys(struct notifier_block *this, unsigned long code,
	295	void *unused)
	296	{
12b7a152 WVS	297	if (code == SYS_DOWN \|\| code == SYS_HALT)
	298	sbc8360_stop(); /* Disable the SBC8360 Watchdog */
	299
3809ad38 IM	300	return NOTIFY_DONE;
	301	}
	302
	303	/*
	304	* Kernel Interfaces
	305	*/
	306
62322d25	307	static const struct file_operations sbc8360_fops = {
3809ad38 IM	308	.owner = THIS_MODULE,
	309	.llseek = no_llseek,
	310	.write = sbc8360_write,
	311	.open = sbc8360_open,
	312	.release = sbc8360_close,
	313	};
	314
	315	static struct miscdevice sbc8360_miscdev = {
	316	.minor = WATCHDOG_MINOR,
	317	.name = "watchdog",
	318	.fops = &sbc8360_fops,
	319	};
	320
	321	/*
	322	* The SBC8360 needs to learn about soft shutdowns in order to
	323	* turn the timebomb registers off.
	324	*/
	325
	326	static struct notifier_block sbc8360_notifier = {
	327	.notifier_call = sbc8360_notify_sys,
	328	};
	329
	330	static int __init sbc8360_init(void)
	331	{
	332	int res;
	333	unsigned long int mseconds = 60000;
	334
fb8f7ba0	335	if (timeout < 0 \|\| timeout > 63) {
27c766aa	336	pr_err("Invalid timeout index (must be 0-63)\n");
fb8f7ba0 AD	337	res = -EINVAL;
fb8f7ba0 AD	338	goto out;
3809ad38 IM	339	}
	340
	341	if (!request_region(SBC8360_ENABLE, 1, "SBC8360")) {
27c766aa	342	pr_err("ENABLE method I/O %X is not available\n",
3809ad38 IM	343	SBC8360_ENABLE);
3809ad38 IM	344	res = -EIO;
fb8f7ba0	345	goto out;
3809ad38 IM	346	}
3809ad38 IM	347	if (!request_region(SBC8360_BASETIME, 1, "SBC8360")) {
27c766aa	348	pr_err("BASETIME method I/O %X is not available\n",
3809ad38 IM	349	SBC8360_BASETIME);
	350	res = -EIO;
	351	goto out_nobasetimereg;
	352	}
	353
	354	res = register_reboot_notifier(&sbc8360_notifier);
	355	if (res) {
27c766aa	356	pr_err("Failed to register reboot notifier\n");
3809ad38 IM	357	goto out_noreboot;
	358	}
	359
fb8f7ba0 AD	360	res = misc_register(&sbc8360_miscdev);
fb8f7ba0 AD	361	if (res) {
27c766aa	362	pr_err("failed to register misc device\n");
fb8f7ba0	363	goto out_nomisc;
3809ad38 IM	364	}
	365
	366	wd_margin = wd_times[timeout][0];
	367	wd_multiplier = wd_times[timeout][1];
	368
	369	if (wd_multiplier == 1)
	370	mseconds = (wd_margin + 1) * 500;
	371	else if (wd_multiplier == 2)
	372	mseconds = (wd_margin + 1) * 5000;
	373	else if (wd_multiplier == 3)
	374	mseconds = (wd_margin + 1) * 50000;
	375	else if (wd_multiplier == 4)
	376	mseconds = (wd_margin + 1) * 100000;
	377
	378	/* My kingdom for the ability to print "0.5 seconds" in the kernel! */
27c766aa	379	pr_info("Timeout set at %ld ms\n", mseconds);
3809ad38 IM	380
	381	return 0;
	382
9f53c8de	383	out_nomisc:
fb8f7ba0	384	unregister_reboot_notifier(&sbc8360_notifier);
9f53c8de	385	out_noreboot:
3809ad38	386	release_region(SBC8360_BASETIME, 1);
9f53c8de	387	out_nobasetimereg:
fb8f7ba0	388	release_region(SBC8360_ENABLE, 1);
9f53c8de	389	out:
3809ad38 IM	390	return res;
	391	}
	392
	393	static void __exit sbc8360_exit(void)
	394	{
	395	misc_deregister(&sbc8360_miscdev);
	396	unregister_reboot_notifier(&sbc8360_notifier);
	397	release_region(SBC8360_ENABLE, 1);
	398	release_region(SBC8360_BASETIME, 1);
	399	}
	400
	401	module_init(sbc8360_init);
	402	module_exit(sbc8360_exit);
	403
	404	MODULE_AUTHOR("Ian E. Morgan <imorgan@webcon.ca>");
	405	MODULE_DESCRIPTION("SBC8360 watchdog driver");
	406	MODULE_LICENSE("GPL");
290995fc	407	MODULE_VERSION("1.01");
3809ad38 IM	408	MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR);
	409
	410	/* end of sbc8360.c */