/* *	Eurotech CPU-1220/1410 on board WDT driver * *	(c) Copyright 2001 Ascensit <support@ascensit.com> *	(c) Copyright 2001 Rodolfo Giometti <giometti@ascensit.com> *	(c) Copyright 2002 Rob Radez <rob@osinvestor.com> * *	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>* *//* Changelog: * * 2002/04/25 - Rob Radez *	clean up #includes *	clean up locking *	make __setup param unique *	proper options in watchdog_info *	add WDIOC_GETSTATUS and WDIOC_SETOPTIONS ioctls *	add expect_close support * * 2001 - Rodolfo Giometti *	Initial release * * 2002.05.30 - Joel Becker <joel.becker@oracle.com> * 	Added Matt Domsch's nowayout module option. */#include <linux/config.h>#include <linux/interrupt.h>#include <linux/module.h>#include <linux/moduleparam.h>#include <linux/types.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 <asm/io.h>#include <asm/uaccess.h>#include <asm/system.h>static unsigned long eurwdt_is_open;static int eurwdt_timeout;static char eur_expect_close;/* * You must set these - there is no sane way to probe for this board. * You can use eurwdt=x,y to set these now. */static int io = 0x3f0;static int irq = 10;static char *ev = "int";#define WDT_TIMEOUT		60                /* 1 minute */#ifdef CONFIG_WATCHDOG_NOWAYOUTstatic int nowayout = 1;#elsestatic int nowayout = 0;#endifmodule_param(nowayout, int, 0);MODULE_PARM_DESC(nowayout, "Watchdog cannot be stopped once started (default=CONFIG_WATCHDOG_NOWAYOUT)");/* * Some symbolic names */#define WDT_CTRL_REG		0x30#define WDT_OUTPIN_CFG		0xe2#define WDT_EVENT_INT		0x00#define WDT_EVENT_REBOOT	0x08#define WDT_UNIT_SEL		0xf1#define WDT_UNIT_SECS		0x80#define WDT_TIMEOUT_VAL		0xf2#define WDT_TIMER_CFG		0xf3module_param(io, int, 0);MODULE_PARM_DESC(io, "Eurotech WDT io port (default=0x3f0)");module_param(irq, int, 0);MODULE_PARM_DESC(irq, "Eurotech WDT irq (default=10)");module_param(ev, charp, 0);MODULE_PARM_DESC(ev, "Eurotech WDT event type (default is `int')");/* * Programming support */static inline void eurwdt_write_reg(u8 index, u8 data){	outb(index, io);	outb(data, io+1);}static inline void eurwdt_lock_chip(void){	outb(0xaa, io);}static inline void eurwdt_unlock_chip(void){	outb(0x55, io);	eurwdt_write_reg(0x07, 0x08);	/* set the logical device */}static inline void eurwdt_set_timeout(int timeout){	eurwdt_write_reg(WDT_TIMEOUT_VAL, (u8) timeout);}static inline void eurwdt_disable_timer(void){	eurwdt_set_timeout(0);}static void eurwdt_activate_timer(void){	eurwdt_disable_timer();	eurwdt_write_reg(WDT_CTRL_REG, 0x01);	/* activate the WDT */	eurwdt_write_reg(WDT_OUTPIN_CFG, !strcmp("int", ev) ? WDT_EVENT_INT : WDT_EVENT_REBOOT);	/* Setting interrupt line */	if (irq == 2 || irq > 15 || irq < 0) {		printk(KERN_ERR ": invalid irq number\n");		irq = 0;	/* if invalid we disable interrupt */	}	if (irq == 0)		printk(KERN_INFO ": interrupt disabled\n");	eurwdt_write_reg(WDT_TIMER_CFG, irq<<4);	eurwdt_write_reg(WDT_UNIT_SEL, WDT_UNIT_SECS);	/* we use seconds */	eurwdt_set_timeout(0);	/* the default timeout */}/* * Kernel methods. */static irqreturn_t eurwdt_interrupt(int irq, void *dev_id, struct pt_regs *regs){	printk(KERN_CRIT "timeout WDT timeout\n");#ifdef ONLY_TESTING	printk(KERN_CRIT "Would Reboot.\n");#else	printk(KERN_CRIT "Initiating system reboot.\n");	machine_restart(NULL);#endif	return IRQ_HANDLED;}/** * eurwdt_ping: * * Reload counter one with the watchdog timeout. */static void eurwdt_ping(void){	/* Write the watchdog default value */	eurwdt_set_timeout(eurwdt_timeout);}/** * eurwdt_write: * @file: file handle to the watchdog * @buf: buffer to write (unused as data does not matter here * @count: count of bytes * @ppos: pointer to the position to write. No seeks allowed * * A write to a watchdog device is defined as a keepalive signal. Any * write of data will do, as we we don't define content meaning. */static ssize_t eurwdt_write(struct file *file, const char __user *buf,size_t count, loff_t *ppos){	if (count) 	{		if (!nowayout) {			size_t i;			eur_expect_close = 0;			for (i = 0; i != count; i++) {				char c;				if(get_user(c, buf+i))					return -EFAULT;				if (c == 'V')					eur_expect_close = 42;			}		}		eurwdt_ping();	/* the default timeout */	}	return count;}/** * eurwdt_ioctl: * @inode: inode of the device * @file: file handle to the device * @cmd: watchdog command * @arg: argument pointer * * The watchdog API defines a common set of functions for all watchdogs * according to their available features. */static int eurwdt_ioctl(struct inode *inode, struct file *file,	unsigned int cmd, unsigned long arg){	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	  = "WDT Eurotech CPU-1220/1410",	};	int time;	int options, retval = -EINVAL;	switch(cmd) {	default:		return -ENOIOCTLCMD;	case WDIOC_GETSUPPORT:		return copy_to_user(argp, &ident, sizeof(ident)) ? -EFAULT : 0;	case WDIOC_GETSTATUS:	case WDIOC_GETBOOTSTATUS:		return put_user(0, p);	case WDIOC_KEEPALIVE:		eurwdt_ping();		return 0;	case WDIOC_SETTIMEOUT:		if (copy_from_user(&time, p, sizeof(int)))			return -EFAULT;		/* Sanity check */		if (time < 0 || time > 255)			return -EINVAL;		eurwdt_timeout = time;		eurwdt_set_timeout(time);		/* Fall */	case WDIOC_GETTIMEOUT:		return put_user(eurwdt_timeout, p);	case WDIOC_SETOPTIONS:		if (get_user(options, p))			return -EFAULT;		if (options & WDIOS_DISABLECARD) {			eurwdt_disable_timer();			retval = 0;		}		if (options & WDIOS_ENABLECARD) {			eurwdt_activate_timer();			eurwdt_ping();			retval = 0;		}		return retval;	}}/** * eurwdt_open: * @inode: inode of device * @file: file handle to device * * The misc device has been opened. The watchdog device is single * open and on opening we load the counter. */static int eurwdt_open(struct inode *inode, struct file *file){	if (test_and_set_bit(0, &eurwdt_is_open))		return -EBUSY;	eurwdt_timeout = WDT_TIMEOUT;	/* initial timeout */	/* Activate the WDT */	eurwdt_activate_timer();	return nonseekable_open(inode, file);}/** * eurwdt_release: * @inode: inode to board * @file: file handle to board * * The watchdog has a configurable API. There is a religious dispute * between people who want their watchdog to be able to shut down and * those who want to be sure if the watchdog manager dies the machine * reboots. In the former case we disable the counters, in the latter * case you have to open it again very soon. */static int eurwdt_release(struct inode *inode, struct file *file){	if (eur_expect_close == 42) {		eurwdt_disable_timer();	} else {		printk(KERN_CRIT "eurwdt: Unexpected close, not stopping watchdog!\n");		eurwdt_ping();	}	clear_bit(0, &eurwdt_is_open);	eur_expect_close = 0;	return 0;}/** * eurwdt_notify_sys: * @this: our notifier block * @code: the event being reported * @unused: unused * * Our notifier is called on system shutdowns. We want to turn the card * off at reboot otherwise the machine will reboot again during memory * test or worse yet during the following fsck. This would suck, in fact * trust me - if it happens it does suck. */static int eurwdt_notify_sys(struct notifier_block *this, unsigned long code,	void *unused){	if (code == SYS_DOWN || code == SYS_HALT) {		/* Turn the card off */		eurwdt_disable_timer();	}	return NOTIFY_DONE;}/* * Kernel Interfaces */static struct file_operations eurwdt_fops = {	.owner	= THIS_MODULE,	.llseek	= no_llseek,	.write	= eurwdt_write,	.ioctl	= eurwdt_ioctl,	.open	= eurwdt_open,	.release	= eurwdt_release,};static struct miscdevice eurwdt_miscdev = {	.minor	= WATCHDOG_MINOR,	.name	= "watchdog",	.fops	= &eurwdt_fops,};/* * The WDT card needs to learn about soft shutdowns in order to * turn the timebomb registers off. */static struct notifier_block eurwdt_notifier = {	.notifier_call = eurwdt_notify_sys,};/** * cleanup_module: * * Unload the watchdog. You cannot do this with any file handles open. * If your watchdog is set to continue ticking on close and you unload * it, well it keeps ticking. We won't get the interrupt but the board * will not touch PC memory so all is fine. You just have to load a new * module in 60 seconds or reboot. */static void __exit eurwdt_exit(void){	eurwdt_lock_chip();	misc_deregister(&eurwdt_miscdev);	unregister_reboot_notifier(&eurwdt_notifier);	release_region(io, 2);	free_irq(irq, NULL);}/** * eurwdt_init: * * Set up the WDT watchdog board. After grabbing the resources * we require we need also to unlock the device. * The open() function will actually kick the board off. */static int __init eurwdt_init(void){	int ret;	ret = misc_register(&eurwdt_miscdev);	if (ret) {		printk(KERN_ERR "eurwdt: can't misc_register on minor=%d\n",		WATCHDOG_MINOR);		goto out;	}	ret = request_irq(irq, eurwdt_interrupt, SA_INTERRUPT, "eurwdt", NULL);	if(ret) {		printk(KERN_ERR "eurwdt: IRQ %d is not free.\n", irq);		goto outmisc;	}	if (!request_region(io, 2, "eurwdt")) {		printk(KERN_ERR "eurwdt: IO %X is not free.\n", io);		ret = -EBUSY;		goto outirq;	}	ret = register_reboot_notifier(&eurwdt_notifier);	if (ret) {		printk(KERN_ERR "eurwdt: can't register reboot notifier (err=%d)\n", ret);		goto outreg;	}	eurwdt_unlock_chip();	ret = 0;	printk(KERN_INFO "Eurotech WDT driver 0.01 at %X (Interrupt %d)"		" - timeout event: %s\n",		io, irq, (!strcmp("int", ev) ? "int" : "reboot"));out:	return ret;outreg:	release_region(io, 2);outirq:	free_irq(irq, NULL);outmisc:	misc_deregister(&eurwdt_miscdev);	goto out;}module_init(eurwdt_init);module_exit(eurwdt_exit);MODULE_AUTHOR("Rodolfo Giometti");MODULE_DESCRIPTION("Driver for Eurotech CPU-1220/1410 on board watchdog");MODULE_LICENSE("GPL");MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR);