[mirror_ubuntu-artful-kernel.git] / drivers / watchdog / sc1200wdt.c

/*
 *	National Semiconductor PC87307/PC97307 (ala SC1200) WDT driver
 *	(c) Copyright 2002 Zwane Mwaikambo <zwane@commfireservices.com>,
 *			All Rights Reserved.
 *	Based on wdt.c and wdt977.c by Alan Cox and Woody Suwalski respectively.
 *
 *	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.
 *
 *	The author(s) of this software shall not be held liable for damages
 *	of any nature resulting due to the use of this software. This
 *	software is provided AS-IS with no warranties.
 *
 *	Changelog:
 *	20020220 Zwane Mwaikambo	Code based on datasheet, no hardware.
 *	20020221 Zwane Mwaikambo	Cleanups as suggested by Jeff Garzik
 *					and Alan Cox.
 *	20020222 Zwane Mwaikambo	Added probing.
 *	20020225 Zwane Mwaikambo	Added ISAPNP support.
 *	20020412 Rob Radez		Broke out start/stop functions
 *		 <rob@osinvestor.com>	Return proper status instead of
 *					temperature warning
 *					Add WDIOC_GETBOOTSTATUS and
 *					WDIOC_SETOPTIONS ioctls
 *					Fix CONFIG_WATCHDOG_NOWAYOUT
 *	20020530 Joel Becker		Add Matt Domsch's nowayout module
 *					option
 *	20030116 Adam Belay		Updated to the latest pnp code
 *
 */

#include <linux/module.h>
#include <linux/moduleparam.h>
#include <linux/miscdevice.h>
#include <linux/watchdog.h>
#include <linux/ioport.h>
#include <linux/spinlock.h>
#include <linux/notifier.h>
#include <linux/reboot.h>
#include <linux/init.h>
#include <linux/pnp.h>
#include <linux/fs.h>
#include <linux/semaphore.h>
#include <linux/io.h>
#include <linux/uaccess.h>

#define SC1200_MODULE_VER	"build 20020303"
#define SC1200_MODULE_NAME	"sc1200wdt"
#define PFX			SC1200_MODULE_NAME ": "

#define	MAX_TIMEOUT	255	/* 255 minutes */
#define PMIR		(io)	/* Power Management Index Register */
#define PMDR		(io+1)	/* Power Management Data Register */

/* Data Register indexes */
#define FER1		0x00	/* Function enable register 1 */
#define FER2		0x01	/* Function enable register 2 */
#define PMC1		0x02	/* Power Management Ctrl 1 */
#define PMC2		0x03	/* Power Management Ctrl 2 */
#define PMC3		0x04	/* Power Management Ctrl 3 */
#define WDTO		0x05	/* Watchdog timeout register */
#define	WDCF		0x06	/* Watchdog config register */
#define WDST		0x07	/* Watchdog status register */

/* WDCF bitfields - which devices assert WDO */
#define KBC_IRQ		0x01	/* Keyboard Controller */
#define MSE_IRQ		0x02	/* Mouse */
#define UART1_IRQ	0x03	/* Serial0 */
#define UART2_IRQ	0x04	/* Serial1 */
/* 5 -7 are reserved */

static char banner[] __initdata = KERN_INFO PFX SC1200_MODULE_VER;
static int timeout = 1;
static int io = -1;
static int io_len = 2;		/* for non plug and play */
static unsigned long open_flag;
static char expect_close;
static DEFINE_SPINLOCK(sc1200wdt_lock);	/* io port access serialisation */

#if defined CONFIG_PNP
static int isapnp = 1;
static struct pnp_dev *wdt_dev;

module_param(isapnp, int, 0);
MODULE_PARM_DESC(isapnp,
	"When set to 0 driver ISA PnP support will be disabled");
#endif

module_param(io, int, 0);
MODULE_PARM_DESC(io, "io port");
module_param(timeout, int, 0);
MODULE_PARM_DESC(timeout, "range is 0-255 minutes, default is 1");

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) ")");


/* Read from Data Register */
static inline void __sc1200wdt_read_data(unsigned char index,
						unsigned char *data)
{
	outb_p(index, PMIR);
	*data = inb(PMDR);
}

static void sc1200wdt_read_data(unsigned char index, unsigned char *data)
{
	spin_lock(&sc1200wdt_lock);
	__sc1200wdt_read_data(index, data);
	spin_unlock(&sc1200wdt_lock);
}

/* Write to Data Register */
static inline void __sc1200wdt_write_data(unsigned char index,
						unsigned char data)
{
	outb_p(index, PMIR);
	outb(data, PMDR);
}

static inline void sc1200wdt_write_data(unsigned char index,
						unsigned char data)
{
	spin_lock(&sc1200wdt_lock);
	__sc1200wdt_write_data(index, data);
	spin_unlock(&sc1200wdt_lock);
}


static void sc1200wdt_start(void)
{
	unsigned char reg;
	spin_lock(&sc1200wdt_lock);

	__sc1200wdt_read_data(WDCF, &reg);
	/* assert WDO when any of the following interrupts are triggered too */
	reg |= (KBC_IRQ | MSE_IRQ | UART1_IRQ | UART2_IRQ);
	__sc1200wdt_write_data(WDCF, reg);
	/* set the timeout and get the ball rolling */
	__sc1200wdt_write_data(WDTO, timeout);

	spin_unlock(&sc1200wdt_lock);
}

static void sc1200wdt_stop(void)
{
	sc1200wdt_write_data(WDTO, 0);
}

/* This returns the status of the WDO signal, inactive high. */
static inline int sc1200wdt_status(void)
{
	unsigned char ret;

	sc1200wdt_read_data(WDST, &ret);
	/* If the bit is inactive, the watchdog is enabled, so return
	 * KEEPALIVEPING which is a bit of a kludge because there's nothing
	 * else for enabled/disabled status
	 */
	return (ret & 0x01) ? 0 : WDIOF_KEEPALIVEPING;
}

static int sc1200wdt_open(struct inode *inode, struct file *file)
{
	/* allow one at a time */
	if (test_and_set_bit(0, &open_flag))
		return -EBUSY;

	if (timeout > MAX_TIMEOUT)
		timeout = MAX_TIMEOUT;

	sc1200wdt_start();
	printk(KERN_INFO PFX "Watchdog enabled, timeout = %d min(s)", timeout);

	return nonseekable_open(inode, file);
}


static long sc1200wdt_ioctl(struct file *file, unsigned int cmd,
						unsigned long arg)
{
	int new_timeout;
	void __user *argp = (void __user *)arg;
	int __user *p = argp;
	static const struct watchdog_info ident = {
		.options = WDIOF_KEEPALIVEPING | WDIOF_SETTIMEOUT |
							WDIOF_MAGICCLOSE,
		.firmware_version = 0,
		.identity = "PC87307/PC97307",
	};

	switch (cmd) {

	case WDIOC_GETSUPPORT:
		if (copy_to_user(argp, &ident, sizeof ident))
			return -EFAULT;
		return 0;

	case WDIOC_GETSTATUS:
		return put_user(sc1200wdt_status(), p);

	case WDIOC_GETBOOTSTATUS:
		return put_user(0, p);

	case WDIOC_KEEPALIVE:
		sc1200wdt_write_data(WDTO, timeout);
		return 0;

	case WDIOC_SETTIMEOUT:
		if (get_user(new_timeout, p))
			return -EFAULT;
		/* the API states this is given in secs */
		new_timeout /= 60;
		if (new_timeout < 0 || new_timeout > MAX_TIMEOUT)
			return -EINVAL;
		timeout = new_timeout;
		sc1200wdt_write_data(WDTO, timeout);
		/* fall through and return the new timeout */

	case WDIOC_GETTIMEOUT:
		return put_user(timeout * 60, p);

	case WDIOC_SETOPTIONS:
	{
		int options, retval = -EINVAL;

		if (get_user(options, p))
			return -EFAULT;

		if (options & WDIOS_DISABLECARD) {
			sc1200wdt_stop();
			retval = 0;
		}

		if (options & WDIOS_ENABLECARD) {
			sc1200wdt_start();
			retval = 0;
		}

		return retval;
	}
	default:
		return -ENOTTY;
	}
}


static int sc1200wdt_release(struct inode *inode, struct file *file)
{
	if (expect_close == 42) {
		sc1200wdt_stop();
		printk(KERN_INFO PFX "Watchdog disabled\n");
	} else {
		sc1200wdt_write_data(WDTO, timeout);
		printk(KERN_CRIT PFX
			"Unexpected close!, timeout = %d min(s)\n", timeout);
	}
	clear_bit(0, &open_flag);
	expect_close = 0;

	return 0;
}


static ssize_t sc1200wdt_write(struct file *file, const char __user *data,
						size_t len, loff_t *ppos)
{
	if (len) {
		if (!nowayout) {
			size_t i;

			expect_close = 0;

			for (i = 0; i != len; i++) {
				char c;

				if (get_user(c, data+i))
					return -EFAULT;
				if (c == 'V')
					expect_close = 42;
			}
		}

		sc1200wdt_write_data(WDTO, timeout);
		return len;
	}

	return 0;
}


static int sc1200wdt_notify_sys(struct notifier_block *this,
					unsigned long code, void *unused)
{
	if (code == SYS_DOWN || code == SYS_HALT)
		sc1200wdt_stop();

	return NOTIFY_DONE;
}


static struct notifier_block sc1200wdt_notifier = {
	.notifier_call =	sc1200wdt_notify_sys,
};

static const struct file_operations sc1200wdt_fops = {
	.owner		= THIS_MODULE,
	.llseek		= no_llseek,
	.write		= sc1200wdt_write,
	.unlocked_ioctl = sc1200wdt_ioctl,
	.open		= sc1200wdt_open,
	.release	= sc1200wdt_release,
};

static struct miscdevice sc1200wdt_miscdev = {
	.minor		= WATCHDOG_MINOR,
	.name		= "watchdog",
	.fops		= &sc1200wdt_fops,
};


static int __init sc1200wdt_probe(void)
{
	/* The probe works by reading the PMC3 register's default value of 0x0e
	 * there is one caveat, if the device disables the parallel port or any
	 * of the UARTs we won't be able to detect it.
	 * NB. This could be done with accuracy by reading the SID registers,
	 * but we don't have access to those io regions.
	 */

	unsigned char reg;

	sc1200wdt_read_data(PMC3, &reg);
	reg &= 0x0f;		/* we don't want the UART busy bits */
	return (reg == 0x0e) ? 0 : -ENODEV;
}


#if defined CONFIG_PNP

static struct pnp_device_id scl200wdt_pnp_devices[] = {
	/* National Semiconductor PC87307/PC97307 watchdog component */
	{.id = "NSC0800", .driver_data = 0},
	{.id = ""},
};

static int scl200wdt_pnp_probe(struct pnp_dev *dev,
					const struct pnp_device_id *dev_id)
{
	/* this driver only supports one card at a time */
	if (wdt_dev || !isapnp)
		return -EBUSY;

	wdt_dev = dev;
	io = pnp_port_start(wdt_dev, 0);
	io_len = pnp_port_len(wdt_dev, 0);

	if (!request_region(io, io_len, SC1200_MODULE_NAME)) {
		printk(KERN_ERR PFX "Unable to register IO port %#x\n", io);
		return -EBUSY;
	}

	printk(KERN_INFO "scl200wdt: PnP device found at io port %#x/%d\n",
								io, io_len);
	return 0;
}

static void scl200wdt_pnp_remove(struct pnp_dev *dev)
{
	if (wdt_dev) {
		release_region(io, io_len);
		wdt_dev = NULL;
	}
}

static struct pnp_driver scl200wdt_pnp_driver = {
	.name		= "scl200wdt",
	.id_table	= scl200wdt_pnp_devices,
	.probe		= scl200wdt_pnp_probe,
	.remove		= scl200wdt_pnp_remove,
};

#endif /* CONFIG_PNP */


static int __init sc1200wdt_init(void)
{
	int ret;

	printk("%s\n", banner);

#if defined CONFIG_PNP
	if (isapnp) {
		ret = pnp_register_driver(&scl200wdt_pnp_driver);
		if (ret)
			goto out_clean;
	}
#endif

	if (io == -1) {
		printk(KERN_ERR PFX "io parameter must be specified\n");
		ret = -EINVAL;
		goto out_pnp;
	}

#if defined CONFIG_PNP
	/* now that the user has specified an IO port and we haven't detected
	 * any devices, disable pnp support */
	isapnp = 0;
	pnp_unregister_driver(&scl200wdt_pnp_driver);
#endif

	if (!request_region(io, io_len, SC1200_MODULE_NAME)) {
		printk(KERN_ERR PFX "Unable to register IO port %#x\n", io);
		ret = -EBUSY;
		goto out_pnp;
	}

	ret = sc1200wdt_probe();
	if (ret)
		goto out_io;

	ret = register_reboot_notifier(&sc1200wdt_notifier);
	if (ret) {
		printk(KERN_ERR PFX
			"Unable to register reboot notifier err = %d\n", ret);
		goto out_io;
	}

	ret = misc_register(&sc1200wdt_miscdev);
	if (ret) {
		printk(KERN_ERR PFX
			"Unable to register miscdev on minor %d\n",
							WATCHDOG_MINOR);
		goto out_rbt;
	}

	/* ret = 0 */

out_clean:
	return ret;

out_rbt:
	unregister_reboot_notifier(&sc1200wdt_notifier);

out_io:
	release_region(io, io_len);

out_pnp:
#if defined CONFIG_PNP
	if (isapnp)
		pnp_unregister_driver(&scl200wdt_pnp_driver);
#endif
	goto out_clean;
}


static void __exit sc1200wdt_exit(void)
{
	misc_deregister(&sc1200wdt_miscdev);
	unregister_reboot_notifier(&sc1200wdt_notifier);

#if defined CONFIG_PNP
	if (isapnp)
		pnp_unregister_driver(&scl200wdt_pnp_driver);
	else
#endif
	release_region(io, io_len);
}

module_init(sc1200wdt_init);
module_exit(sc1200wdt_exit);

MODULE_AUTHOR("Zwane Mwaikambo <zwane@commfireservices.com>");
MODULE_DESCRIPTION("Driver for National Semiconductor PC87307/PC97307 watchdog component");
MODULE_LICENSE("GPL");
MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR);
Commit	Line	Data
1da177e4 LT	1	/*
	2	* National Semiconductor PC87307/PC97307 (ala SC1200) WDT driver
	3	* (c) Copyright 2002 Zwane Mwaikambo <zwane@commfireservices.com>,
	4	* All Rights Reserved.
	5	* Based on wdt.c and wdt977.c by Alan Cox and Woody Suwalski respectively.
	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	* The author(s) of this software shall not be held liable for damages
	13	* of any nature resulting due to the use of this software. This
	14	* software is provided AS-IS with no warranties.
	15	*
	16	* Changelog:
	17	* 20020220 Zwane Mwaikambo Code based on datasheet, no hardware.
103a1d5c AC	18	* 20020221 Zwane Mwaikambo Cleanups as suggested by Jeff Garzik
103a1d5c AC	19	* and Alan Cox.
1da177e4 LT	20	* 20020222 Zwane Mwaikambo Added probing.
	21	* 20020225 Zwane Mwaikambo Added ISAPNP support.
	22	* 20020412 Rob Radez Broke out start/stop functions
103a1d5c AC	23	* <rob@osinvestor.com> Return proper status instead of
	24	* temperature warning
	25	* Add WDIOC_GETBOOTSTATUS and
	26	* WDIOC_SETOPTIONS ioctls
1da177e4	27	* Fix CONFIG_WATCHDOG_NOWAYOUT
103a1d5c AC	28	* 20020530 Joel Becker Add Matt Domsch's nowayout module
103a1d5c AC	29	* option
1da177e4 LT	30	* 20030116 Adam Belay Updated to the latest pnp code
	31	*
	32	*/
	33
1da177e4 LT	34	#include <linux/module.h>
	35	#include <linux/moduleparam.h>
	36	#include <linux/miscdevice.h>
	37	#include <linux/watchdog.h>
	38	#include <linux/ioport.h>
	39	#include <linux/spinlock.h>
	40	#include <linux/notifier.h>
	41	#include <linux/reboot.h>
	42	#include <linux/init.h>
	43	#include <linux/pnp.h>
	44	#include <linux/fs.h>
6188e10d	45	#include <linux/semaphore.h>
103a1d5c AC	46	#include <linux/io.h>
103a1d5c AC	47	#include <linux/uaccess.h>
1da177e4 LT	48
	49	#define SC1200_MODULE_VER "build 20020303"
	50	#define SC1200_MODULE_NAME "sc1200wdt"
	51	#define PFX SC1200_MODULE_NAME ": "
	52
	53	#define MAX_TIMEOUT 255 /* 255 minutes */
	54	#define PMIR (io) /* Power Management Index Register */
	55	#define PMDR (io+1) /* Power Management Data Register */
	56
	57	/* Data Register indexes */
	58	#define FER1 0x00 /* Function enable register 1 */
	59	#define FER2 0x01 /* Function enable register 2 */
	60	#define PMC1 0x02 /* Power Management Ctrl 1 */
	61	#define PMC2 0x03 /* Power Management Ctrl 2 */
	62	#define PMC3 0x04 /* Power Management Ctrl 3 */
	63	#define WDTO 0x05 /* Watchdog timeout register */
	64	#define WDCF 0x06 /* Watchdog config register */
	65	#define WDST 0x07 /* Watchdog status register */
	66
	67	/* WDCF bitfields - which devices assert WDO */
	68	#define KBC_IRQ 0x01 /* Keyboard Controller */
	69	#define MSE_IRQ 0x02 /* Mouse */
	70	#define UART1_IRQ 0x03 /* Serial0 */
	71	#define UART2_IRQ 0x04 /* Serial1 */
	72	/* 5 -7 are reserved */
	73
	74	static char banner[] __initdata = KERN_INFO PFX SC1200_MODULE_VER;
	75	static int timeout = 1;
	76	static int io = -1;
	77	static int io_len = 2; /* for non plug and play */
103a1d5c	78	static unsigned long open_flag;
1da177e4	79	static char expect_close;
c7dfd0cc	80	static DEFINE_SPINLOCK(sc1200wdt_lock); /* io port access serialisation */
1da177e4 LT	81
	82	#if defined CONFIG_PNP
	83	static int isapnp = 1;
	84	static struct pnp_dev *wdt_dev;
	85
	86	module_param(isapnp, int, 0);
103a1d5c AC	87	MODULE_PARM_DESC(isapnp,
103a1d5c AC	88	"When set to 0 driver ISA PnP support will be disabled");
1da177e4 LT	89	#endif
	90
	91	module_param(io, int, 0);
	92	MODULE_PARM_DESC(io, "io port");
	93	module_param(timeout, int, 0);
	94	MODULE_PARM_DESC(timeout, "range is 0-255 minutes, default is 1");
	95
4bfdf378	96	static int nowayout = WATCHDOG_NOWAYOUT;
1da177e4	97	module_param(nowayout, int, 0);
103a1d5c AC	98	MODULE_PARM_DESC(nowayout,
	99	"Watchdog cannot be stopped once started (default="
	100	__MODULE_STRING(WATCHDOG_NOWAYOUT) ")");
1da177e4 LT	101
	102
	103
	104	/* Read from Data Register */
103a1d5c AC	105	static inline void __sc1200wdt_read_data(unsigned char index,
103a1d5c AC	106	unsigned char *data)
1da177e4	107	{
1da177e4 LT	108	outb_p(index, PMIR);
1da177e4 LT	109	*data = inb(PMDR);
1da177e4 LT	110	}
1da177e4 LT	111
103a1d5c AC	112	static void sc1200wdt_read_data(unsigned char index, unsigned char *data)
	113	{
	114	spin_lock(&sc1200wdt_lock);
	115	__sc1200wdt_read_data(index, data);
	116	spin_unlock(&sc1200wdt_lock);
	117	}
1da177e4 LT	118
1da177e4 LT	119	/* Write to Data Register */
103a1d5c AC	120	static inline void __sc1200wdt_write_data(unsigned char index,
103a1d5c AC	121	unsigned char data)
1da177e4	122	{
1da177e4 LT	123	outb_p(index, PMIR);
1da177e4 LT	124	outb(data, PMDR);
103a1d5c AC	125	}
	126
	127	static inline void sc1200wdt_write_data(unsigned char index,
	128	unsigned char data)
	129	{
	130	spin_lock(&sc1200wdt_lock);
	131	__sc1200wdt_write_data(index, data);
1da177e4 LT	132	spin_unlock(&sc1200wdt_lock);
	133	}
	134
	135
	136	static void sc1200wdt_start(void)
	137	{
	138	unsigned char reg;
103a1d5c	139	spin_lock(&sc1200wdt_lock);
1da177e4	140
103a1d5c	141	__sc1200wdt_read_data(WDCF, &reg);
1da177e4 LT	142	/* assert WDO when any of the following interrupts are triggered too */
1da177e4 LT	143	reg \|= (KBC_IRQ \| MSE_IRQ \| UART1_IRQ \| UART2_IRQ);
103a1d5c	144	__sc1200wdt_write_data(WDCF, reg);
1da177e4	145	/* set the timeout and get the ball rolling */
103a1d5c	146	__sc1200wdt_write_data(WDTO, timeout);
1da177e4	147
103a1d5c AC	148	spin_unlock(&sc1200wdt_lock);
103a1d5c AC	149	}
1da177e4 LT	150
	151	static void sc1200wdt_stop(void)
	152	{
	153	sc1200wdt_write_data(WDTO, 0);
	154	}
	155
1da177e4 LT	156	/* This returns the status of the WDO signal, inactive high. */
	157	static inline int sc1200wdt_status(void)
	158	{
	159	unsigned char ret;
	160
	161	sc1200wdt_read_data(WDST, &ret);
	162	/* If the bit is inactive, the watchdog is enabled, so return
	163	* KEEPALIVEPING which is a bit of a kludge because there's nothing
	164	* else for enabled/disabled status
	165	*/
103a1d5c	166	return (ret & 0x01) ? 0 : WDIOF_KEEPALIVEPING;
1da177e4 LT	167	}
1da177e4 LT	168
1da177e4 LT	169	static int sc1200wdt_open(struct inode inode, struct file file)
1da177e4 LT	170	{
1da177e4	171	/* allow one at a time */
103a1d5c	172	if (test_and_set_bit(0, &open_flag))
1da177e4 LT	173	return -EBUSY;
	174
	175	if (timeout > MAX_TIMEOUT)
	176	timeout = MAX_TIMEOUT;
	177
	178	sc1200wdt_start();
	179	printk(KERN_INFO PFX "Watchdog enabled, timeout = %d min(s)", timeout);
	180
6abe78bf	181	return nonseekable_open(inode, file);
1da177e4 LT	182	}
	183
	184
103a1d5c AC	185	static long sc1200wdt_ioctl(struct file *file, unsigned int cmd,
103a1d5c AC	186	unsigned long arg)
1da177e4 LT	187	{
	188	int new_timeout;
	189	void __user argp = (void __user )arg;
	190	int __user *p = argp;
103a1d5c AC	191	static const struct watchdog_info ident = {
	192	.options = WDIOF_KEEPALIVEPING \| WDIOF_SETTIMEOUT \|
	193	WDIOF_MAGICCLOSE,
1da177e4 LT	194	.firmware_version = 0,
	195	.identity = "PC87307/PC97307",
	196	};
	197
	198	switch (cmd) {
1da177e4	199
103a1d5c AC	200	case WDIOC_GETSUPPORT:
	201	if (copy_to_user(argp, &ident, sizeof ident))
	202	return -EFAULT;
	203	return 0;
1da177e4	204
103a1d5c AC	205	case WDIOC_GETSTATUS:
103a1d5c AC	206	return put_user(sc1200wdt_status(), p);
1da177e4	207
103a1d5c AC	208	case WDIOC_GETBOOTSTATUS:
103a1d5c AC	209	return put_user(0, p);
1da177e4	210
103a1d5c AC	211	case WDIOC_KEEPALIVE:
	212	sc1200wdt_write_data(WDTO, timeout);
	213	return 0;
	214
	215	case WDIOC_SETTIMEOUT:
	216	if (get_user(new_timeout, p))
	217	return -EFAULT;
	218	/* the API states this is given in secs */
	219	new_timeout /= 60;
	220	if (new_timeout < 0 \|\| new_timeout > MAX_TIMEOUT)
	221	return -EINVAL;
	222	timeout = new_timeout;
	223	sc1200wdt_write_data(WDTO, timeout);
	224	/* fall through and return the new timeout */
1da177e4	225
103a1d5c AC	226	case WDIOC_GETTIMEOUT:
103a1d5c AC	227	return put_user(timeout * 60, p);
1da177e4	228
103a1d5c AC	229	case WDIOC_SETOPTIONS:
	230	{
	231	int options, retval = -EINVAL;
1da177e4	232
103a1d5c AC	233	if (get_user(options, p))
103a1d5c AC	234	return -EFAULT;
1da177e4	235
103a1d5c AC	236	if (options & WDIOS_DISABLECARD) {
	237	sc1200wdt_stop();
	238	retval = 0;
	239	}
1da177e4	240
103a1d5c AC	241	if (options & WDIOS_ENABLECARD) {
	242	sc1200wdt_start();
	243	retval = 0;
1da177e4	244	}
103a1d5c AC	245
	246	return retval;
	247	}
	248	default:
	249	return -ENOTTY;
1da177e4 LT	250	}
	251	}
	252
	253
	254	static int sc1200wdt_release(struct inode inode, struct file file)
	255	{
	256	if (expect_close == 42) {
	257	sc1200wdt_stop();
	258	printk(KERN_INFO PFX "Watchdog disabled\n");
	259	} else {
	260	sc1200wdt_write_data(WDTO, timeout);
103a1d5c AC	261	printk(KERN_CRIT PFX
103a1d5c AC	262	"Unexpected close!, timeout = %d min(s)\n", timeout);
1da177e4	263	}
103a1d5c	264	clear_bit(0, &open_flag);
1da177e4 LT	265	expect_close = 0;
	266
	267	return 0;
	268	}
	269
	270
103a1d5c AC	271	static ssize_t sc1200wdt_write(struct file file, const char __user data,
103a1d5c AC	272	size_t len, loff_t *ppos)
1da177e4 LT	273	{
	274	if (len) {
	275	if (!nowayout) {
	276	size_t i;
	277
	278	expect_close = 0;
	279
	280	for (i = 0; i != len; i++) {
	281	char c;
	282
	283	if (get_user(c, data+i))
	284	return -EFAULT;
	285	if (c == 'V')
	286	expect_close = 42;
	287	}
	288	}
	289
	290	sc1200wdt_write_data(WDTO, timeout);
	291	return len;
	292	}
	293
	294	return 0;
	295	}
	296
	297
103a1d5c AC	298	static int sc1200wdt_notify_sys(struct notifier_block *this,
103a1d5c AC	299	unsigned long code, void *unused)
1da177e4 LT	300	{
	301	if (code == SYS_DOWN \|\| code == SYS_HALT)
	302	sc1200wdt_stop();
	303
	304	return NOTIFY_DONE;
	305	}
	306
	307
103a1d5c	308	static struct notifier_block sc1200wdt_notifier = {
1da177e4 LT	309	.notifier_call = sc1200wdt_notify_sys,
	310	};
	311
103a1d5c	312	static const struct file_operations sc1200wdt_fops = {
1da177e4 LT	313	.owner = THIS_MODULE,
	314	.llseek = no_llseek,
	315	.write = sc1200wdt_write,
103a1d5c	316	.unlocked_ioctl = sc1200wdt_ioctl,
1da177e4 LT	317	.open = sc1200wdt_open,
	318	.release = sc1200wdt_release,
	319	};
	320
103a1d5c	321	static struct miscdevice sc1200wdt_miscdev = {
1da177e4 LT	322	.minor = WATCHDOG_MINOR,
	323	.name = "watchdog",
	324	.fops = &sc1200wdt_fops,
	325	};
	326
	327
	328	static int __init sc1200wdt_probe(void)
	329	{
	330	/* The probe works by reading the PMC3 register's default value of 0x0e
	331	* there is one caveat, if the device disables the parallel port or any
	332	* of the UARTs we won't be able to detect it.
103a1d5c AC	333	* NB. This could be done with accuracy by reading the SID registers,
103a1d5c AC	334	* but we don't have access to those io regions.
1da177e4 LT	335	*/
	336
	337	unsigned char reg;
	338
	339	sc1200wdt_read_data(PMC3, &reg);
103a1d5c	340	reg &= 0x0f; /* we don't want the UART busy bits */
1da177e4 LT	341	return (reg == 0x0e) ? 0 : -ENODEV;
	342	}
	343
	344
	345	#if defined CONFIG_PNP
	346
	347	static struct pnp_device_id scl200wdt_pnp_devices[] = {
	348	/* National Semiconductor PC87307/PC97307 watchdog component */
	349	{.id = "NSC0800", .driver_data = 0},
	350	{.id = ""},
	351	};
	352
103a1d5c AC	353	static int scl200wdt_pnp_probe(struct pnp_dev *dev,
103a1d5c AC	354	const struct pnp_device_id *dev_id)
1da177e4 LT	355	{
	356	/* this driver only supports one card at a time */
	357	if (wdt_dev \|\| !isapnp)
	358	return -EBUSY;
	359
	360	wdt_dev = dev;
	361	io = pnp_port_start(wdt_dev, 0);
	362	io_len = pnp_port_len(wdt_dev, 0);
	363
	364	if (!request_region(io, io_len, SC1200_MODULE_NAME)) {
	365	printk(KERN_ERR PFX "Unable to register IO port %#x\n", io);
	366	return -EBUSY;
	367	}
	368
103a1d5c AC	369	printk(KERN_INFO "scl200wdt: PnP device found at io port %#x/%d\n",
103a1d5c AC	370	io, io_len);
1da177e4 LT	371	return 0;
	372	}
	373
103a1d5c	374	static void scl200wdt_pnp_remove(struct pnp_dev *dev)
1da177e4	375	{
103a1d5c	376	if (wdt_dev) {
1da177e4 LT	377	release_region(io, io_len);
	378	wdt_dev = NULL;
	379	}
	380	}
	381
	382	static struct pnp_driver scl200wdt_pnp_driver = {
	383	.name = "scl200wdt",
	384	.id_table = scl200wdt_pnp_devices,
	385	.probe = scl200wdt_pnp_probe,
	386	.remove = scl200wdt_pnp_remove,
	387	};
	388
	389	#endif /* CONFIG_PNP */
	390
	391
	392	static int __init sc1200wdt_init(void)
	393	{
	394	int ret;
	395
7071e522	396	printk("%s\n", banner);
1da177e4	397
1da177e4 LT	398	#if defined CONFIG_PNP
	399	if (isapnp) {
	400	ret = pnp_register_driver(&scl200wdt_pnp_driver);
	401	if (ret)
	402	goto out_clean;
	403	}
	404	#endif
	405
	406	if (io == -1) {
	407	printk(KERN_ERR PFX "io parameter must be specified\n");
	408	ret = -EINVAL;
150ed8ed	409	goto out_pnp;
1da177e4 LT	410	}
	411
	412	#if defined CONFIG_PNP
	413	/* now that the user has specified an IO port and we haven't detected
	414	* any devices, disable pnp support */
	415	isapnp = 0;
	416	pnp_unregister_driver(&scl200wdt_pnp_driver);
	417	#endif
	418
	419	if (!request_region(io, io_len, SC1200_MODULE_NAME)) {
	420	printk(KERN_ERR PFX "Unable to register IO port %#x\n", io);
	421	ret = -EBUSY;
150ed8ed	422	goto out_pnp;
1da177e4 LT	423	}
	424
	425	ret = sc1200wdt_probe();
	426	if (ret)
	427	goto out_io;
	428
	429	ret = register_reboot_notifier(&sc1200wdt_notifier);
	430	if (ret) {
103a1d5c AC	431	printk(KERN_ERR PFX
103a1d5c AC	432	"Unable to register reboot notifier err = %d\n", ret);
1da177e4 LT	433	goto out_io;
	434	}
	435
	436	ret = misc_register(&sc1200wdt_miscdev);
	437	if (ret) {
103a1d5c AC	438	printk(KERN_ERR PFX
	439	"Unable to register miscdev on minor %d\n",
	440	WATCHDOG_MINOR);
1da177e4 LT	441	goto out_rbt;
	442	}
	443
	444	/* ret = 0 */
	445
	446	out_clean:
	447	return ret;
	448
	449	out_rbt:
	450	unregister_reboot_notifier(&sc1200wdt_notifier);
	451
	452	out_io:
	453	release_region(io, io_len);
	454
150ed8ed AM	455	out_pnp:
	456	#if defined CONFIG_PNP
	457	if (isapnp)
	458	pnp_unregister_driver(&scl200wdt_pnp_driver);
	459	#endif
1da177e4 LT	460	goto out_clean;
	461	}
	462
	463
	464	static void __exit sc1200wdt_exit(void)
	465	{
	466	misc_deregister(&sc1200wdt_miscdev);
	467	unregister_reboot_notifier(&sc1200wdt_notifier);
	468
	469	#if defined CONFIG_PNP
103a1d5c	470	if (isapnp)
1da177e4 LT	471	pnp_unregister_driver(&scl200wdt_pnp_driver);
	472	else
	473	#endif
	474	release_region(io, io_len);
	475	}
	476
	477	module_init(sc1200wdt_init);
	478	module_exit(sc1200wdt_exit);
	479
	480	MODULE_AUTHOR("Zwane Mwaikambo <zwane@commfireservices.com>");
	481	MODULE_DESCRIPTION("Driver for National Semiconductor PC87307/PC97307 watchdog component");
	482	MODULE_LICENSE("GPL");
	483	MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR);