[mirror_ubuntu-bionic-kernel.git] / drivers / char / 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 <asm/semaphore.h>
#include <asm/io.h>
#include <asm/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 struct semaphore open_sem;
static char expect_close;
static spinlock_t 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)
{
	spin_lock(&sc1200wdt_lock);
	outb_p(index, PMIR);
	*data = inb(PMDR);
	spin_unlock(&sc1200wdt_lock);
}


/* Write to Data Register */
static inline void sc1200wdt_write_data(unsigned char index, unsigned char data)
{
	spin_lock(&sc1200wdt_lock);
	outb_p(index, PMIR);
	outb(data, PMDR);
	spin_unlock(&sc1200wdt_lock);
}


static void sc1200wdt_start(void)
{
	unsigned char reg;

	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);
}


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;	/* bits 1 - 7 are undefined */
}


static int sc1200wdt_open(struct inode *inode, struct file *file)
{
	nonseekable_open(inode, file);

	/* allow one at a time */
	if (down_trylock(&open_sem))
		return -EBUSY;

	if (timeout > MAX_TIMEOUT)
		timeout = MAX_TIMEOUT;

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

	return 0;
}


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

	switch (cmd) {
		default:
			return -ENOTTY;

		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;
		}
	}
}


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);
	}
	up(&open_sem);
	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,
	.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);

	spin_lock_init(&sc1200wdt_lock);
	sema_init(&open_sem, 1);

#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.
	18	* 20020221 Zwane Mwaikambo Cleanups as suggested by Jeff Garzik and Alan Cox.
	19	* 20020222 Zwane Mwaikambo Added probing.
	20	* 20020225 Zwane Mwaikambo Added ISAPNP support.
	21	* 20020412 Rob Radez Broke out start/stop functions
	22	* <rob@osinvestor.com> Return proper status instead of temperature warning
	23	* Add WDIOC_GETBOOTSTATUS and WDIOC_SETOPTIONS ioctls
	24	* Fix CONFIG_WATCHDOG_NOWAYOUT
	25	* 20020530 Joel Becker Add Matt Domsch's nowayout module option
	26	* 20030116 Adam Belay Updated to the latest pnp code
	27	*
	28	*/
	29
1da177e4 LT	30	#include <linux/module.h>
	31	#include <linux/moduleparam.h>
	32	#include <linux/miscdevice.h>
	33	#include <linux/watchdog.h>
	34	#include <linux/ioport.h>
	35	#include <linux/spinlock.h>
	36	#include <linux/notifier.h>
	37	#include <linux/reboot.h>
	38	#include <linux/init.h>
	39	#include <linux/pnp.h>
	40	#include <linux/fs.h>
1da177e4 LT	41
	42	#include <asm/semaphore.h>
	43	#include <asm/io.h>
	44	#include <asm/uaccess.h>
	45
	46	#define SC1200_MODULE_VER "build 20020303"
	47	#define SC1200_MODULE_NAME "sc1200wdt"
	48	#define PFX SC1200_MODULE_NAME ": "
	49
	50	#define MAX_TIMEOUT 255 /* 255 minutes */
	51	#define PMIR (io) /* Power Management Index Register */
	52	#define PMDR (io+1) /* Power Management Data Register */
	53
	54	/* Data Register indexes */
	55	#define FER1 0x00 /* Function enable register 1 */
	56	#define FER2 0x01 /* Function enable register 2 */
	57	#define PMC1 0x02 /* Power Management Ctrl 1 */
	58	#define PMC2 0x03 /* Power Management Ctrl 2 */
	59	#define PMC3 0x04 /* Power Management Ctrl 3 */
	60	#define WDTO 0x05 /* Watchdog timeout register */
	61	#define WDCF 0x06 /* Watchdog config register */
	62	#define WDST 0x07 /* Watchdog status register */
	63
	64	/* WDCF bitfields - which devices assert WDO */
	65	#define KBC_IRQ 0x01 /* Keyboard Controller */
	66	#define MSE_IRQ 0x02 /* Mouse */
	67	#define UART1_IRQ 0x03 /* Serial0 */
	68	#define UART2_IRQ 0x04 /* Serial1 */
	69	/* 5 -7 are reserved */
	70
	71	static char banner[] __initdata = KERN_INFO PFX SC1200_MODULE_VER;
	72	static int timeout = 1;
	73	static int io = -1;
	74	static int io_len = 2; /* for non plug and play */
	75	static struct semaphore open_sem;
	76	static char expect_close;
	77	static spinlock_t sc1200wdt_lock; /* io port access serialisation */
	78
	79	#if defined CONFIG_PNP
	80	static int isapnp = 1;
	81	static struct pnp_dev *wdt_dev;
	82
	83	module_param(isapnp, int, 0);
	84	MODULE_PARM_DESC(isapnp, "When set to 0 driver ISA PnP support will be disabled");
	85	#endif
	86
	87	module_param(io, int, 0);
	88	MODULE_PARM_DESC(io, "io port");
	89	module_param(timeout, int, 0);
	90	MODULE_PARM_DESC(timeout, "range is 0-255 minutes, default is 1");
	91
4bfdf378	92	static int nowayout = WATCHDOG_NOWAYOUT;
1da177e4	93	module_param(nowayout, int, 0);
bffda5c8	94	MODULE_PARM_DESC(nowayout, "Watchdog cannot be stopped once started (default=" __MODULE_STRING(WATCHDOG_NOWAYOUT) ")");
1da177e4 LT	95
	96
	97
	98	/* Read from Data Register */
	99	static inline void sc1200wdt_read_data(unsigned char index, unsigned char *data)
	100	{
	101	spin_lock(&sc1200wdt_lock);
	102	outb_p(index, PMIR);
	103	*data = inb(PMDR);
	104	spin_unlock(&sc1200wdt_lock);
	105	}
	106
	107
	108	/* Write to Data Register */
	109	static inline void sc1200wdt_write_data(unsigned char index, unsigned char data)
	110	{
	111	spin_lock(&sc1200wdt_lock);
	112	outb_p(index, PMIR);
	113	outb(data, PMDR);
	114	spin_unlock(&sc1200wdt_lock);
	115	}
	116
	117
	118	static void sc1200wdt_start(void)
	119	{
	120	unsigned char reg;
	121
	122	sc1200wdt_read_data(WDCF, &reg);
	123	/* assert WDO when any of the following interrupts are triggered too */
	124	reg \|= (KBC_IRQ \| MSE_IRQ \| UART1_IRQ \| UART2_IRQ);
	125	sc1200wdt_write_data(WDCF, reg);
	126	/* set the timeout and get the ball rolling */
	127	sc1200wdt_write_data(WDTO, timeout);
	128	}
	129
	130
	131	static void sc1200wdt_stop(void)
	132	{
	133	sc1200wdt_write_data(WDTO, 0);
	134	}
	135
	136
	137	/* This returns the status of the WDO signal, inactive high. */
	138	static inline int sc1200wdt_status(void)
	139	{
	140	unsigned char ret;
	141
	142	sc1200wdt_read_data(WDST, &ret);
	143	/* If the bit is inactive, the watchdog is enabled, so return
	144	* KEEPALIVEPING which is a bit of a kludge because there's nothing
	145	* else for enabled/disabled status
	146	*/
	147	return (ret & 0x01) ? 0 : WDIOF_KEEPALIVEPING; /* bits 1 - 7 are undefined */
	148	}
	149
	150
	151	static int sc1200wdt_open(struct inode inode, struct file file)
	152	{
	153	nonseekable_open(inode, file);
	154
	155	/* allow one at a time */
	156	if (down_trylock(&open_sem))
	157	return -EBUSY;
	158
159	if (timeout > MAX_TIMEOUT)
160	timeout = MAX_TIMEOUT;
161
162	sc1200wdt_start();
163	printk(KERN_INFO PFX "Watchdog enabled, timeout = %d min(s)", timeout);
164
165	return 0;
166	}
167
168
169	static int sc1200wdt_ioctl(struct inode inode, struct file file, unsigned int cmd, unsigned long arg)
170	{
171	int new_timeout;
172	void __user argp = (void __user )arg;
173	int __user *p = argp;
174	static struct watchdog_info ident = {
175	.options = WDIOF_KEEPALIVEPING \| WDIOF_SETTIMEOUT \| WDIOF_MAGICCLOSE,
176	.firmware_version = 0,
177	.identity = "PC87307/PC97307",
178	};
179
180	switch (cmd) {
181	default:
795b89d2	182	return -ENOTTY;
1da177e4 LT	183
	184	case WDIOC_GETSUPPORT:
	185	if (copy_to_user(argp, &ident, sizeof ident))
	186	return -EFAULT;
	187	return 0;
	188
	189	case WDIOC_GETSTATUS:
	190	return put_user(sc1200wdt_status(), p);
	191
	192	case WDIOC_GETBOOTSTATUS:
	193	return put_user(0, p);
	194
	195	case WDIOC_KEEPALIVE:
	196	sc1200wdt_write_data(WDTO, timeout);
	197	return 0;
	198
	199	case WDIOC_SETTIMEOUT:
	200	if (get_user(new_timeout, p))
	201	return -EFAULT;
	202
	203	/* the API states this is given in secs */
	204	new_timeout /= 60;
	205	if (new_timeout < 0 \|\| new_timeout > MAX_TIMEOUT)
	206	return -EINVAL;
	207
	208	timeout = new_timeout;
	209	sc1200wdt_write_data(WDTO, timeout);
	210	/* fall through and return the new timeout */
	211
	212	case WDIOC_GETTIMEOUT:
	213	return put_user(timeout * 60, p);
	214
	215	case WDIOC_SETOPTIONS:
	216	{
	217	int options, retval = -EINVAL;
	218
	219	if (get_user(options, p))
	220	return -EFAULT;
	221
	222	if (options & WDIOS_DISABLECARD) {
	223	sc1200wdt_stop();
	224	retval = 0;
	225	}
	226
	227	if (options & WDIOS_ENABLECARD) {
	228	sc1200wdt_start();
	229	retval = 0;
	230	}
	231
	232	return retval;
	233	}
	234	}
	235	}
	236
	237
	238	static int sc1200wdt_release(struct inode inode, struct file file)
	239	{
	240	if (expect_close == 42) {
	241	sc1200wdt_stop();
	242	printk(KERN_INFO PFX "Watchdog disabled\n");
	243	} else {
	244	sc1200wdt_write_data(WDTO, timeout);
	245	printk(KERN_CRIT PFX "Unexpected close!, timeout = %d min(s)\n", timeout);
	246	}
247	up(&open_sem);
248	expect_close = 0;
249
250	return 0;
251	}
252
253
254	static ssize_t sc1200wdt_write(struct file file, const char __user data, size_t len, loff_t *ppos)
255	{
256	if (len) {
257	if (!nowayout) {
258	size_t i;
259
260	expect_close = 0;
261
262	for (i = 0; i != len; i++) {
263	char c;
264
265	if (get_user(c, data+i))
266	return -EFAULT;
267	if (c == 'V')
268	expect_close = 42;
269	}
270	}
271
272	sc1200wdt_write_data(WDTO, timeout);
273	return len;
274	}
275
276	return 0;
277	}
278
279
280	static int sc1200wdt_notify_sys(struct notifier_block this, unsigned long code, void unused)
281	{
282	if (code == SYS_DOWN \|\| code == SYS_HALT)
283	sc1200wdt_stop();
284
285	return NOTIFY_DONE;
286	}
287
288
289	static struct notifier_block sc1200wdt_notifier =
290	{
291	.notifier_call = sc1200wdt_notify_sys,
292	};
293
62322d25	294	static const struct file_operations sc1200wdt_fops =
1da177e4 LT	295	{
	296	.owner = THIS_MODULE,
	297	.llseek = no_llseek,
	298	.write = sc1200wdt_write,
	299	.ioctl = sc1200wdt_ioctl,
	300	.open = sc1200wdt_open,
	301	.release = sc1200wdt_release,
	302	};
	303
	304	static struct miscdevice sc1200wdt_miscdev =
	305	{
	306	.minor = WATCHDOG_MINOR,
	307	.name = "watchdog",
	308	.fops = &sc1200wdt_fops,
	309	};
	310
	311
	312	static int __init sc1200wdt_probe(void)
	313	{
	314	/* The probe works by reading the PMC3 register's default value of 0x0e
	315	* there is one caveat, if the device disables the parallel port or any
	316	* of the UARTs we won't be able to detect it.
	317	* Nb. This could be done with accuracy by reading the SID registers, but
	318	* we don't have access to those io regions.
	319	*/
	320
	321	unsigned char reg;
	322
	323	sc1200wdt_read_data(PMC3, &reg);
	324	reg &= 0x0f; /* we don't want the UART busy bits */
	325	return (reg == 0x0e) ? 0 : -ENODEV;
	326	}
	327
	328
	329	#if defined CONFIG_PNP
	330
	331	static struct pnp_device_id scl200wdt_pnp_devices[] = {
	332	/* National Semiconductor PC87307/PC97307 watchdog component */
	333	{.id = "NSC0800", .driver_data = 0},
	334	{.id = ""},
	335	};
	336
	337	static int scl200wdt_pnp_probe(struct pnp_dev * dev, const struct pnp_device_id *dev_id)
	338	{
	339	/* this driver only supports one card at a time */
	340	if (wdt_dev \|\| !isapnp)
	341	return -EBUSY;
	342
	343	wdt_dev = dev;
	344	io = pnp_port_start(wdt_dev, 0);
	345	io_len = pnp_port_len(wdt_dev, 0);
	346
	347	if (!request_region(io, io_len, SC1200_MODULE_NAME)) {
	348	printk(KERN_ERR PFX "Unable to register IO port %#x\n", io);
	349	return -EBUSY;
	350	}
	351
	352	printk(KERN_INFO "scl200wdt: PnP device found at io port %#x/%d\n", io, io_len);
	353	return 0;
	354	}
	355
	356	static void scl200wdt_pnp_remove(struct pnp_dev * dev)
	357	{
	358	if (wdt_dev){
359	release_region(io, io_len);
360	wdt_dev = NULL;
361	}
362	}
363
364	static struct pnp_driver scl200wdt_pnp_driver = {
365	.name = "scl200wdt",
366	.id_table = scl200wdt_pnp_devices,
367	.probe = scl200wdt_pnp_probe,
368	.remove = scl200wdt_pnp_remove,
369	};
370
371	#endif /* CONFIG_PNP */
372
373
374	static int __init sc1200wdt_init(void)
375	{
376	int ret;
377
7071e522	378	printk("%s\n", banner);
1da177e4 LT	379
	380	spin_lock_init(&sc1200wdt_lock);
	381	sema_init(&open_sem, 1);
	382
	383	#if defined CONFIG_PNP
	384	if (isapnp) {
	385	ret = pnp_register_driver(&scl200wdt_pnp_driver);
	386	if (ret)
	387	goto out_clean;
	388	}
	389	#endif
	390
	391	if (io == -1) {
	392	printk(KERN_ERR PFX "io parameter must be specified\n");
	393	ret = -EINVAL;
150ed8ed	394	goto out_pnp;
1da177e4 LT	395	}
	396
	397	#if defined CONFIG_PNP
	398	/* now that the user has specified an IO port and we haven't detected
	399	* any devices, disable pnp support */
	400	isapnp = 0;
	401	pnp_unregister_driver(&scl200wdt_pnp_driver);
	402	#endif
	403
	404	if (!request_region(io, io_len, SC1200_MODULE_NAME)) {
	405	printk(KERN_ERR PFX "Unable to register IO port %#x\n", io);
	406	ret = -EBUSY;
150ed8ed	407	goto out_pnp;
1da177e4 LT	408	}
	409
	410	ret = sc1200wdt_probe();
	411	if (ret)
	412	goto out_io;
	413
	414	ret = register_reboot_notifier(&sc1200wdt_notifier);
	415	if (ret) {
	416	printk(KERN_ERR PFX "Unable to register reboot notifier err = %d\n", ret);
	417	goto out_io;
	418	}
	419
	420	ret = misc_register(&sc1200wdt_miscdev);
	421	if (ret) {
	422	printk(KERN_ERR PFX "Unable to register miscdev on minor %d\n", WATCHDOG_MINOR);
	423	goto out_rbt;
	424	}
	425
	426	/* ret = 0 */
	427
	428	out_clean:
	429	return ret;
	430
	431	out_rbt:
	432	unregister_reboot_notifier(&sc1200wdt_notifier);
	433
	434	out_io:
	435	release_region(io, io_len);
	436
150ed8ed AM	437	out_pnp:
	438	#if defined CONFIG_PNP
	439	if (isapnp)
	440	pnp_unregister_driver(&scl200wdt_pnp_driver);
	441	#endif
1da177e4 LT	442	goto out_clean;
	443	}
	444
	445
	446	static void __exit sc1200wdt_exit(void)
	447	{
	448	misc_deregister(&sc1200wdt_miscdev);
	449	unregister_reboot_notifier(&sc1200wdt_notifier);
	450
	451	#if defined CONFIG_PNP
	452	if(isapnp)
	453	pnp_unregister_driver(&scl200wdt_pnp_driver);
	454	else
	455	#endif
	456	release_region(io, io_len);
	457	}
	458
	459	module_init(sc1200wdt_init);
	460	module_exit(sc1200wdt_exit);
	461
	462	MODULE_AUTHOR("Zwane Mwaikambo <zwane@commfireservices.com>");
	463	MODULE_DESCRIPTION("Driver for National Semiconductor PC87307/PC97307 watchdog component");
	464	MODULE_LICENSE("GPL");
	465	MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR);