[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/config.h>
#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 -ENOIOCTLCMD;	/* Keep Pavel Machek amused ;) */

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