drivers/char/watchdog/mixcomwd.c - linux - Git at Google

 /*
  * MixCom Watchdog: A Simple Hardware Watchdog Device
  * Based on Softdog driver by Alan Cox and PC Watchdog driver by Ken Hollis
  *
  * Author: Gergely Madarasz <gorgo@itc.hu>
  *
  * Copyright (c) 1999 ITConsult-Pro Co. <info@itc.hu>
  *
  * 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.
  *
  * Version 0.1 (99/04/15):
  *		- first version
  *
  * Version 0.2 (99/06/16):
  *		- added kernel timer watchdog ping after close
  *		  since the hardware does not support watchdog shutdown
  *
  * Version 0.3 (99/06/21):
  *		- added WDIOC_GETSTATUS and WDIOC_GETSUPPORT ioctl calls
  *
  * Version 0.3.1 (99/06/22):
  *		- allow module removal while internal timer is active,
  *		  print warning about probable reset
  *
  * Version 0.4 (99/11/15):
  *		- support for one more type board
  *
  * Version 0.5 (2001/12/14) Matt Domsch <Matt_Domsch@dell.com>
  *              - added nowayout module option to override CONFIG_WATCHDOG_NOWAYOUT
  *
  */

 #define VERSION "0.5"

 #include <linux/module.h>
 #include <linux/moduleparam.h>
 #include <linux/types.h>
 #include <linux/miscdevice.h>
 #include <linux/ioport.h>
 #include <linux/watchdog.h>
 #include <linux/fs.h>
 #include <linux/reboot.h>
 #include <linux/init.h>
 #include <linux/jiffies.h>
 #include <linux/timer.h>
 #include <asm/uaccess.h>
 #include <asm/io.h>

 static int mixcomwd_ioports[] = { 0x180, 0x280, 0x380, 0x000 };

 #define MIXCOM_WATCHDOG_OFFSET 0xc10
 #define MIXCOM_ID 0x11
 #define FLASHCOM_WATCHDOG_OFFSET 0x4
 #define FLASHCOM_ID 0x18

 static unsigned long mixcomwd_opened; /* long req'd for setbit --RR */

 static int watchdog_port;
 static int mixcomwd_timer_alive;
 static DEFINE_TIMER(mixcomwd_timer, NULL, 0, 0);
 static char expect_close;

 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 mixcomwd_ping(void)
 {
 	outb_p(55,watchdog_port);
 	return;
 }

 static void mixcomwd_timerfun(unsigned long d)
 {
 	mixcomwd_ping();

 	mod_timer(&mixcomwd_timer,jiffies+ 5*HZ);
 }

 /*
  *	Allow only one person to hold it open
  */

 static int mixcomwd_open(struct inode *inode, struct file *file)
 {
 	if(test_and_set_bit(0,&mixcomwd_opened)) {
 		return -EBUSY;
 	}
 	mixcomwd_ping();

 	if (nowayout) {
 		/*
 		 * fops_get() code via open() has already done
 		 * a try_module_get() so it is safe to do the
 		 * __module_get().
 		 */
 		__module_get(THIS_MODULE);
 	} else {
 		if(mixcomwd_timer_alive) {
 			del_timer(&mixcomwd_timer);
 			mixcomwd_timer_alive=0;
 		}
 	}
 	return nonseekable_open(inode, file);
 }

 static int mixcomwd_release(struct inode *inode, struct file *file)
 {
 	if (expect_close == 42) {
 		if(mixcomwd_timer_alive) {
 			printk(KERN_ERR "mixcomwd: release called while internal timer alive");
 			return -EBUSY;
 		}
 		init_timer(&mixcomwd_timer);
 		mixcomwd_timer.expires=jiffies + 5 * HZ;
 		mixcomwd_timer.function=mixcomwd_timerfun;
 		mixcomwd_timer.data=0;
 		mixcomwd_timer_alive=1;
 		add_timer(&mixcomwd_timer);
 	} else {
 		printk(KERN_CRIT "mixcomwd: WDT device closed unexpectedly.  WDT will not stop!\n");
 	}

 	clear_bit(0,&mixcomwd_opened);
 	expect_close=0;
 	return 0;
 }


 static ssize_t mixcomwd_write(struct file *file, const char __user *data, size_t len, loff_t *ppos)
 {
 	if(len)
 	{
 		if (!nowayout) {
 			size_t i;

 			/* In case it was set long ago */
 			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;
 			}
 		}
 		mixcomwd_ping();
 	}
 	return len;
 }

 static int mixcomwd_ioctl(struct inode *inode, struct file *file,
 	unsigned int cmd, unsigned long arg)
 {
 	void __user *argp = (void __user *)arg;
 	int __user *p = argp;
 	int status;
 	static struct watchdog_info ident = {
 		.options = WDIOF_KEEPALIVEPING | WDIOF_MAGICCLOSE,
 		.firmware_version = 1,
 		.identity = "MixCOM watchdog",
 	};

 	switch(cmd)
 	{
 		case WDIOC_GETSTATUS:
 			status=mixcomwd_opened;
 			if (!nowayout) {
 				status|=mixcomwd_timer_alive;
 			}
 			if (copy_to_user(p, &status, sizeof(int))) {
 				return -EFAULT;
 			}
 			break;
 		case WDIOC_GETSUPPORT:
 			if (copy_to_user(argp, &ident, sizeof(ident))) {
 				return -EFAULT;
 			}
 			break;
 		case WDIOC_KEEPALIVE:
 			mixcomwd_ping();
 			break;
 		default:
 			return -ENOIOCTLCMD;
 	}
 	return 0;
 }

 static const struct file_operations mixcomwd_fops=
 {
 	.owner		= THIS_MODULE,
 	.llseek		= no_llseek,
 	.write		= mixcomwd_write,
 	.ioctl		= mixcomwd_ioctl,
 	.open		= mixcomwd_open,
 	.release	= mixcomwd_release,
 };

 static struct miscdevice mixcomwd_miscdev=
 {
 	.minor	= WATCHDOG_MINOR,
 	.name	= "watchdog",
 	.fops	= &mixcomwd_fops,
 };

 static int __init mixcomwd_checkcard(int port)
 {
 	int id;

 	port += MIXCOM_WATCHDOG_OFFSET;
 	if (!request_region(port, 1, "MixCOM watchdog")) {
 		return 0;
 	}

 	id=inb_p(port) & 0x3f;
 	if(id!=MIXCOM_ID) {
 		release_region(port, 1);
 		return 0;
 	}
 	return port;
 }

 static int __init flashcom_checkcard(int port)
 {
 	int id;

 	port += FLASHCOM_WATCHDOG_OFFSET;
 	if (!request_region(port, 1, "MixCOM watchdog")) {
 		return 0;
 	}

 	id=inb_p(port);
  	if(id!=FLASHCOM_ID) {
 		release_region(port, 1);
 		return 0;
 	}
  	return port;
  }

 static int __init mixcomwd_init(void)
 {
 	int i;
 	int ret;
 	int found=0;

 	for (i = 0; !found && mixcomwd_ioports[i] != 0; i++) {
 		watchdog_port = mixcomwd_checkcard(mixcomwd_ioports[i]);
 		if (watchdog_port) {
 			found = 1;
 		}
 	}

 	/* The FlashCOM card can be set up at 0x300 -> 0x378, in 0x8 jumps */
 	for (i = 0x300; !found && i < 0x380; i+=0x8) {
 		watchdog_port = flashcom_checkcard(i);
 		if (watchdog_port) {
 			found = 1;
 		}
 	}

 	if (!found) {
 		printk("mixcomwd: No card detected, or port not available.\n");
 		return -ENODEV;
 	}

 	ret = misc_register(&mixcomwd_miscdev);
 	if (ret)
 	{
 		release_region(watchdog_port, 1);
 		return ret;
 	}

 	printk(KERN_INFO "MixCOM watchdog driver v%s, watchdog port at 0x%3x\n",VERSION,watchdog_port);

 	return 0;
 }

 static void __exit mixcomwd_exit(void)
 {
 	if (!nowayout) {
 		if(mixcomwd_timer_alive) {
 			printk(KERN_WARNING "mixcomwd: I quit now, hardware will"
 			       " probably reboot!\n");
 			del_timer(&mixcomwd_timer);
 			mixcomwd_timer_alive=0;
 		}
 	}
 	release_region(watchdog_port,1);
 	misc_deregister(&mixcomwd_miscdev);
 }

 module_init(mixcomwd_init);
 module_exit(mixcomwd_exit);

 MODULE_AUTHOR("Gergely Madarasz <gorgo@itc.hu>");
 MODULE_DESCRIPTION("MixCom Watchdog driver");
 MODULE_LICENSE("GPL");
 MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR);
	/*
	* MixCom Watchdog: A Simple Hardware Watchdog Device
	* Based on Softdog driver by Alan Cox and PC Watchdog driver by Ken Hollis
	*
	* Author: Gergely Madarasz <gorgo@itc.hu>
	*
	* Copyright (c) 1999 ITConsult-Pro Co. <info@itc.hu>
	*
	* 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.
	*
	* Version 0.1 (99/04/15):
	* - first version
	*
	* Version 0.2 (99/06/16):
	* - added kernel timer watchdog ping after close
	* since the hardware does not support watchdog shutdown
	*
	* Version 0.3 (99/06/21):
	* - added WDIOC_GETSTATUS and WDIOC_GETSUPPORT ioctl calls
	*
	* Version 0.3.1 (99/06/22):
	* - allow module removal while internal timer is active,
	* print warning about probable reset
	*
	* Version 0.4 (99/11/15):
	* - support for one more type board
	*
	* Version 0.5 (2001/12/14) Matt Domsch <Matt_Domsch@dell.com>
	* - added nowayout module option to override CONFIG_WATCHDOG_NOWAYOUT
	*
	*/

	#define VERSION "0.5"

	#include <linux/module.h>
	#include <linux/moduleparam.h>
	#include <linux/types.h>
	#include <linux/miscdevice.h>
	#include <linux/ioport.h>
	#include <linux/watchdog.h>
	#include <linux/fs.h>
	#include <linux/reboot.h>
	#include <linux/init.h>
	#include <linux/jiffies.h>
	#include <linux/timer.h>
	#include <asm/uaccess.h>
	#include <asm/io.h>

	static int mixcomwd_ioports[] = { 0x180, 0x280, 0x380, 0x000 };

	#define MIXCOM_WATCHDOG_OFFSET 0xc10
	#define MIXCOM_ID 0x11
	#define FLASHCOM_WATCHDOG_OFFSET 0x4
	#define FLASHCOM_ID 0x18

	static unsigned long mixcomwd_opened; /* long req'd for setbit --RR */

	static int watchdog_port;
	static int mixcomwd_timer_alive;
	static DEFINE_TIMER(mixcomwd_timer, NULL, 0, 0);
	static char expect_close;

	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 mixcomwd_ping(void)
	{
	outb_p(55,watchdog_port);
	return;
	}

	static void mixcomwd_timerfun(unsigned long d)
	{
	mixcomwd_ping();

	mod_timer(&mixcomwd_timer,jiffies+ 5*HZ);
	}

	/*
	* Allow only one person to hold it open
	*/

	static int mixcomwd_open(struct inode inode, struct file file)
	{
	if(test_and_set_bit(0,&mixcomwd_opened)) {
	return -EBUSY;
	}
	mixcomwd_ping();

	if (nowayout) {
	/*
	* fops_get() code via open() has already done
	* a try_module_get() so it is safe to do the
	* __module_get().
	*/
	__module_get(THIS_MODULE);
	} else {
	if(mixcomwd_timer_alive) {
	del_timer(&mixcomwd_timer);
	mixcomwd_timer_alive=0;
	}
	}
	return nonseekable_open(inode, file);
	}

	static int mixcomwd_release(struct inode inode, struct file file)
	{
	if (expect_close == 42) {
	if(mixcomwd_timer_alive) {
	printk(KERN_ERR "mixcomwd: release called while internal timer alive");
	return -EBUSY;
	}
	init_timer(&mixcomwd_timer);
	mixcomwd_timer.expires=jiffies + 5 * HZ;
	mixcomwd_timer.function=mixcomwd_timerfun;
	mixcomwd_timer.data=0;
	mixcomwd_timer_alive=1;
	add_timer(&mixcomwd_timer);
	} else {
	printk(KERN_CRIT "mixcomwd: WDT device closed unexpectedly. WDT will not stop!\n");
	}

	clear_bit(0,&mixcomwd_opened);
	expect_close=0;
	return 0;
	}


	static ssize_t mixcomwd_write(struct file file, const char __user data, size_t len, loff_t *ppos)
	{
	if(len)
	{
	if (!nowayout) {
	size_t i;

	/* In case it was set long ago */
	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;
	}
	}
	mixcomwd_ping();
	}
	return len;
	}

	static int mixcomwd_ioctl(struct inode inode, struct file file,
	unsigned int cmd, unsigned long arg)
	{
	void __user argp = (void __user )arg;
	int __user *p = argp;
	int status;
	static struct watchdog_info ident = {
	.options = WDIOF_KEEPALIVEPING \| WDIOF_MAGICCLOSE,
	.firmware_version = 1,
	.identity = "MixCOM watchdog",
	};

	switch(cmd)
	{
	case WDIOC_GETSTATUS:
	status=mixcomwd_opened;
	if (!nowayout) {
	status\|=mixcomwd_timer_alive;
	}
	if (copy_to_user(p, &status, sizeof(int))) {
	return -EFAULT;
	}
	break;
	case WDIOC_GETSUPPORT:
	if (copy_to_user(argp, &ident, sizeof(ident))) {
	return -EFAULT;
	}
	break;
	case WDIOC_KEEPALIVE:
	mixcomwd_ping();
	break;
	default:
	return -ENOIOCTLCMD;
	}
	return 0;
	}

	static const struct file_operations mixcomwd_fops=
	{
	.owner = THIS_MODULE,
	.llseek = no_llseek,
	.write = mixcomwd_write,
	.ioctl = mixcomwd_ioctl,
	.open = mixcomwd_open,
	.release = mixcomwd_release,
	};

	static struct miscdevice mixcomwd_miscdev=
	{
	.minor = WATCHDOG_MINOR,
	.name = "watchdog",
	.fops = &mixcomwd_fops,
	};

	static int __init mixcomwd_checkcard(int port)
	{
	int id;

	port += MIXCOM_WATCHDOG_OFFSET;
	if (!request_region(port, 1, "MixCOM watchdog")) {
	return 0;
	}

	id=inb_p(port) & 0x3f;
	if(id!=MIXCOM_ID) {
	release_region(port, 1);
	return 0;
	}
	return port;
	}

	static int __init flashcom_checkcard(int port)
	{
	int id;

	port += FLASHCOM_WATCHDOG_OFFSET;
	if (!request_region(port, 1, "MixCOM watchdog")) {
	return 0;
	}

	id=inb_p(port);
	if(id!=FLASHCOM_ID) {
	release_region(port, 1);
	return 0;
	}
	return port;
	}

	static int __init mixcomwd_init(void)
	{
	int i;
	int ret;
	int found=0;

	for (i = 0; !found && mixcomwd_ioports[i] != 0; i++) {
	watchdog_port = mixcomwd_checkcard(mixcomwd_ioports[i]);
	if (watchdog_port) {
	found = 1;
	}
	}

	/* The FlashCOM card can be set up at 0x300 -> 0x378, in 0x8 jumps */
	for (i = 0x300; !found && i < 0x380; i+=0x8) {
	watchdog_port = flashcom_checkcard(i);
	if (watchdog_port) {
	found = 1;
	}
	}

	if (!found) {
	printk("mixcomwd: No card detected, or port not available.\n");
	return -ENODEV;
	}

	ret = misc_register(&mixcomwd_miscdev);
	if (ret)
	{
	release_region(watchdog_port, 1);
	return ret;
	}

	printk(KERN_INFO "MixCOM watchdog driver v%s, watchdog port at 0x%3x\n",VERSION,watchdog_port);

	return 0;
	}

	static void __exit mixcomwd_exit(void)
	{
	if (!nowayout) {
	if(mixcomwd_timer_alive) {
	printk(KERN_WARNING "mixcomwd: I quit now, hardware will"
	" probably reboot!\n");
	del_timer(&mixcomwd_timer);
	mixcomwd_timer_alive=0;
	}
	}
	release_region(watchdog_port,1);
	misc_deregister(&mixcomwd_miscdev);
	}

	module_init(mixcomwd_init);
	module_exit(mixcomwd_exit);

	MODULE_AUTHOR("Gergely Madarasz <gorgo@itc.hu>");
	MODULE_DESCRIPTION("MixCom Watchdog driver");
	MODULE_LICENSE("GPL");
	MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR);