[deliverable/linux.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 <linux/pci.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=CONFIG_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_clean;
	}

#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_clean;
	}

	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);

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