/* *	ICP Wafer 5823 Single Board Computer WDT driver *      http://www.icpamerica.com/wafer_5823.php *      May also work on other similar models * *	(c) Copyright 2002 Justin Cormack <justin@street-vision.com> * *      Release 0.02 * *	Based on advantechwdt.c which is based on wdt.c. *	Original copyright messages: * *	(c) Copyright 1996-1997 Alan Cox <alan@redhat.com>, All Rights Reserved. *				http://www.redhat.com * *	This program is free software; you can redistribute it and/or *	modify it under the terms of the GNU General Public License *	as published by the Free Software Foundation; either version *	2 of the License, or (at your option) any later version. * *	Neither Alan Cox nor CymruNet Ltd. admit liability nor provide *	warranty for any of this software. This material is provided *	"AS-IS" and at no charge. * *	(c) Copyright 1995    Alan Cox <alan@lxorguk.ukuu.org.uk> * */#include <linux/module.h>#include <linux/moduleparam.h>#include <linux/miscdevice.h>#include <linux/watchdog.h>#include <linux/fs.h>#include <linux/ioport.h>#include <linux/notifier.h>#include <linux/reboot.h>#include <linux/init.h>#include <linux/spinlock.h>#include <asm/io.h>#include <asm/uaccess.h>#define WATCHDOG_NAME "Wafer 5823 WDT"#define PFX WATCHDOG_NAME ": "#define WD_TIMO 60			/* 60 sec default timeout */static unsigned long wafwdt_is_open;static char expect_close;static spinlock_t wafwdt_lock;/* *	You must set these - there is no sane way to probe for this board. * *      To enable, write the timeout value in seconds (1 to 255) to I/O *      port WDT_START, then read the port to start the watchdog. To pat *      the dog, read port WDT_STOP to stop the timer, then read WDT_START *      to restart it again. */static int wdt_stop = 0x843;static int wdt_start = 0x443;static int timeout = WD_TIMO;  /* in seconds */module_param(timeout, int, 0);MODULE_PARM_DESC(timeout, "Watchdog timeout in seconds. 1<= timeout <=255, default=" __MODULE_STRING(WD_TIMO) ".");static int nowayout = WATCHDOG_NOWAYOUT;module_param(nowayout, int, 0);MODULE_PARM_DESC(nowayout, "Watchdog cannot be stopped once started (default=CONFIG_WATCHDOG_NOWAYOUT)");static void wafwdt_ping(void){	/* pat watchdog */	spin_lock(&wafwdt_lock);	inb_p(wdt_stop);	inb_p(wdt_start);	spin_unlock(&wafwdt_lock);}static void wafwdt_start(void){	/* start up watchdog */	outb_p(timeout, wdt_start);	inb_p(wdt_start);}static voidwafwdt_stop(void){	/* stop watchdog */	inb_p(wdt_stop);}static ssize_t wafwdt_write(struct file *file, const char __user *buf, size_t count, loff_t * ppos){	/* See if we got the magic character 'V' and reload the timer */	if (count) {		if (!nowayout) {			size_t i;			/* In case it was set long ago */			expect_close = 0;			/* scan to see whether or not we got the magic character */			for (i = 0; i != count; i++) {				char c;				if (get_user(c, buf + i))					return -EFAULT;				if (c == 'V')					expect_close = 42;			}		}		/* Well, anyhow someone wrote to us, we should return that favour */		wafwdt_ping();	}	return count;}static int wafwdt_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 = 1,		.identity = "Wafer 5823 WDT",	};	switch (cmd) {	case WDIOC_GETSUPPORT:		if (copy_to_user(argp, &ident, sizeof (ident)))			return -EFAULT;		break;	case WDIOC_GETSTATUS:	case WDIOC_GETBOOTSTATUS:		return put_user(0, p);	case WDIOC_KEEPALIVE:		wafwdt_ping();		break;	case WDIOC_SETTIMEOUT:		if (get_user(new_timeout, p))			return -EFAULT;		if ((new_timeout < 1) || (new_timeout > 255))			return -EINVAL;		timeout = new_timeout;		wafwdt_stop();		wafwdt_start();		/* Fall */	case WDIOC_GETTIMEOUT:		return put_user(timeout, p);	case WDIOC_SETOPTIONS:	{		int options, retval = -EINVAL;		if (get_user(options, p))			return -EFAULT;		if (options & WDIOS_DISABLECARD) {			wafwdt_start();			retval = 0;		}		if (options & WDIOS_ENABLECARD) {			wafwdt_stop();			retval = 0;		}		return retval;	}	default:		return -ENOIOCTLCMD;	}	return 0;}static int wafwdt_open(struct inode *inode, struct file *file){	if (test_and_set_bit(0, &wafwdt_is_open))		return -EBUSY;	/*	 *      Activate	 */	wafwdt_start();	return nonseekable_open(inode, file);}static intwafwdt_close(struct inode *inode, struct file *file){	if (expect_close == 42) {		wafwdt_stop();	} else {		printk(KERN_CRIT PFX "WDT device closed unexpectedly.  WDT will not stop!\n");		wafwdt_ping();	}	clear_bit(0, &wafwdt_is_open);	expect_close = 0;	return 0;}/* *	Notifier for system down */static int wafwdt_notify_sys(struct notifier_block *this, unsigned long code, void *unused){	if (code == SYS_DOWN || code == SYS_HALT) {		/* Turn the WDT off */		wafwdt_stop();	}	return NOTIFY_DONE;}/* *	Kernel Interfaces */static struct file_operations wafwdt_fops = {	.owner		= THIS_MODULE,	.llseek		= no_llseek,	.write		= wafwdt_write,	.ioctl		= wafwdt_ioctl,	.open		= wafwdt_open,	.release	= wafwdt_close,};static struct miscdevice wafwdt_miscdev = {	.minor	= WATCHDOG_MINOR,	.name	= "watchdog",	.fops	= &wafwdt_fops,};/* *	The WDT needs to learn about soft shutdowns in order to *	turn the timebomb registers off. */static struct notifier_block wafwdt_notifier = {	.notifier_call = wafwdt_notify_sys,};static int __init wafwdt_init(void){	int ret;	printk(KERN_INFO "WDT driver for Wafer 5823 single board computer initialising.\n");	spin_lock_init(&wafwdt_lock);	if (timeout < 1 || timeout > 255) {		timeout = WD_TIMO;		printk (KERN_INFO PFX "timeout value must be 1<=x<=255, using %d\n",			timeout);	}	if (wdt_stop != wdt_start) {		if(!request_region(wdt_stop, 1, "Wafer 5823 WDT")) {			printk (KERN_ERR PFX "I/O address 0x%04x already in use\n",			wdt_stop);			ret = -EIO;			goto error;		}	}	if(!request_region(wdt_start, 1, "Wafer 5823 WDT")) {		printk (KERN_ERR PFX "I/O address 0x%04x already in use\n",			wdt_start);		ret = -EIO;		goto error2;	}	ret = register_reboot_notifier(&wafwdt_notifier);	if (ret != 0) {		printk (KERN_ERR PFX "cannot register reboot notifier (err=%d)\n",			ret);		goto error3;	}	ret = misc_register(&wafwdt_miscdev);	if (ret != 0) {		printk (KERN_ERR PFX "cannot register miscdev on minor=%d (err=%d)\n",			WATCHDOG_MINOR, ret);		goto error4;	}	printk (KERN_INFO PFX "initialized. timeout=%d sec (nowayout=%d)\n",		timeout, nowayout);	return ret;error4:	unregister_reboot_notifier(&wafwdt_notifier);error3:	release_region(wdt_start, 1);error2:	if (wdt_stop != wdt_start)		release_region(wdt_stop, 1);error:	return ret;}static void __exit wafwdt_exit(void){	misc_deregister(&wafwdt_miscdev);	unregister_reboot_notifier(&wafwdt_notifier);	if(wdt_stop != wdt_start)		release_region(wdt_stop, 1);	release_region(wdt_start, 1);}module_init(wafwdt_init);module_exit(wafwdt_exit);MODULE_AUTHOR("Justin Cormack");MODULE_DESCRIPTION("ICP Wafer 5823 Single Board Computer WDT driver");MODULE_LICENSE("GPL");MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR);/* end of wafer5823wdt.c */