1/* 2 * MixCom Watchdog: A Simple Hardware Watchdog Device 3 * Based on Softdog driver by Alan Cox and PC Watchdog driver by Ken Hollis 4 * 5 * Author: Gergely Madarasz <gorgo@itc.hu> 6 * 7 * Copyright (c) 1999 ITConsult-Pro Co. <info@itc.hu> 8 * 9 * This program is free software; you can redistribute it and/or 10 * modify it under the terms of the GNU General Public License 11 * as published by the Free Software Foundation; either version 12 * 2 of the License, or (at your option) any later version. 13 * 14 * Version 0.1 (99/04/15): 15 * - first version 16 * 17 * Version 0.2 (99/06/16): 18 * - added kernel timer watchdog ping after close 19 * since the hardware does not support watchdog shutdown 20 * 21 * Version 0.3 (99/06/21): 22 * - added WDIOC_GETSTATUS and WDIOC_GETSUPPORT ioctl calls 23 * 24 * Version 0.3.1 (99/06/22): 25 * - allow module removal while internal timer is active, 26 * print warning about probable reset 27 * 28 * Version 0.4 (99/11/15): 29 * - support for one more type board 30 * 31 * Version 0.5 (2001/12/14) Matt Domsch <Matt_Domsch@dell.com> 32 * - added nowayout module option to override CONFIG_WATCHDOG_NOWAYOUT 33 * 34 */ 35 36#define VERSION "0.5" 37 38#include <linux/module.h> 39#include <linux/moduleparam.h> 40#include <linux/types.h> 41#include <linux/miscdevice.h> 42#include <linux/ioport.h> 43#include <linux/watchdog.h> 44#include <linux/fs.h> 45#include <linux/reboot.h> 46#include <linux/init.h> 47#include <linux/jiffies.h> 48#include <linux/timer.h> 49#include <asm/uaccess.h> 50#include <asm/io.h> 51 52static int mixcomwd_ioports[] = { 0x180, 0x280, 0x380, 0x000 }; 53 54#define MIXCOM_WATCHDOG_OFFSET 0xc10 55#define MIXCOM_ID 0x11 56#define FLASHCOM_WATCHDOG_OFFSET 0x4 57#define FLASHCOM_ID 0x18 58 59static void mixcomwd_timerfun(unsigned long d); 60 61static unsigned long mixcomwd_opened; /* long req'd for setbit --RR */ 62 63static int watchdog_port; 64static int mixcomwd_timer_alive; 65static DEFINE_TIMER(mixcomwd_timer, mixcomwd_timerfun, 0, 0); 66static char expect_close; 67 68static int nowayout = WATCHDOG_NOWAYOUT; 69module_param(nowayout, int, 0); 70MODULE_PARM_DESC(nowayout, "Watchdog cannot be stopped once started (default=" __MODULE_STRING(WATCHDOG_NOWAYOUT) ")"); 71 72static void mixcomwd_ping(void) 73{ 74 outb_p(55,watchdog_port); 75 return; 76} 77 78static void mixcomwd_timerfun(unsigned long d) 79{ 80 mixcomwd_ping(); 81 82 mod_timer(&mixcomwd_timer, jiffies + 5 * HZ); 83} 84 85/* 86 * Allow only one person to hold it open 87 */ 88 89static int mixcomwd_open(struct inode *inode, struct file *file) 90{ 91 if(test_and_set_bit(0,&mixcomwd_opened)) { 92 return -EBUSY; 93 } 94 mixcomwd_ping(); 95 96 if (nowayout) { 97 /* 98 * fops_get() code via open() has already done 99 * a try_module_get() so it is safe to do the 100 * __module_get(). 101 */ 102 __module_get(THIS_MODULE); 103 } else { 104 if(mixcomwd_timer_alive) { 105 del_timer(&mixcomwd_timer); 106 mixcomwd_timer_alive=0; 107 } 108 } 109 return nonseekable_open(inode, file); 110} 111 112static int mixcomwd_release(struct inode *inode, struct file *file) 113{ 114 if (expect_close == 42) { 115 if(mixcomwd_timer_alive) { 116 printk(KERN_ERR "mixcomwd: release called while internal timer alive"); 117 return -EBUSY; 118 } 119 mixcomwd_timer_alive=1; 120 mod_timer(&mixcomwd_timer, jiffies + 5 * HZ); 121 } else { 122 printk(KERN_CRIT "mixcomwd: WDT device closed unexpectedly. WDT will not stop!\n"); 123 } 124 125 clear_bit(0,&mixcomwd_opened); 126 expect_close=0; 127 return 0; 128} 129 130 131static ssize_t mixcomwd_write(struct file *file, const char __user *data, size_t len, loff_t *ppos) 132{ 133 if(len) 134 { 135 if (!nowayout) { 136 size_t i; 137 138 /* In case it was set long ago */ 139 expect_close = 0; 140 141 for (i = 0; i != len; i++) { 142 char c; 143 if (get_user(c, data + i)) 144 return -EFAULT; 145 if (c == 'V') 146 expect_close = 42; 147 } 148 } 149 mixcomwd_ping(); 150 } 151 return len; 152} 153 154static int mixcomwd_ioctl(struct inode *inode, struct file *file, 155 unsigned int cmd, unsigned long arg) 156{ 157 void __user *argp = (void __user *)arg; 158 int __user *p = argp; 159 int status; 160 static struct watchdog_info ident = { 161 .options = WDIOF_KEEPALIVEPING | WDIOF_MAGICCLOSE, 162 .firmware_version = 1, 163 .identity = "MixCOM watchdog", 164 }; 165 166 switch(cmd) 167 { 168 case WDIOC_GETSTATUS: 169 status=mixcomwd_opened; 170 if (!nowayout) { 171 status|=mixcomwd_timer_alive; 172 } 173 if (copy_to_user(p, &status, sizeof(int))) { 174 return -EFAULT; 175 } 176 break; 177 case WDIOC_GETSUPPORT: 178 if (copy_to_user(argp, &ident, sizeof(ident))) { 179 return -EFAULT; 180 } 181 break; 182 case WDIOC_KEEPALIVE: 183 mixcomwd_ping(); 184 break; 185 default: 186 return -ENOTTY; 187 } 188 return 0; 189} 190 191static const struct file_operations mixcomwd_fops= 192{ 193 .owner = THIS_MODULE, 194 .llseek = no_llseek, 195 .write = mixcomwd_write, 196 .ioctl = mixcomwd_ioctl, 197 .open = mixcomwd_open, 198 .release = mixcomwd_release, 199}; 200 201static struct miscdevice mixcomwd_miscdev= 202{ 203 .minor = WATCHDOG_MINOR, 204 .name = "watchdog", 205 .fops = &mixcomwd_fops, 206}; 207 208static int __init mixcomwd_checkcard(int port) 209{ 210 int id; 211 212 port += MIXCOM_WATCHDOG_OFFSET; 213 if (!request_region(port, 1, "MixCOM watchdog")) { 214 return 0; 215 } 216 217 id=inb_p(port) & 0x3f; 218 if(id!=MIXCOM_ID) { 219 release_region(port, 1); 220 return 0; 221 } 222 return port; 223} 224 225static int __init flashcom_checkcard(int port) 226{ 227 int id; 228 229 port += FLASHCOM_WATCHDOG_OFFSET; 230 if (!request_region(port, 1, "MixCOM watchdog")) { 231 return 0; 232 } 233 234 id=inb_p(port); 235 if(id!=FLASHCOM_ID) { 236 release_region(port, 1); 237 return 0; 238 } 239 return port; 240 } 241 242static int __init mixcomwd_init(void) 243{ 244 int i; 245 int ret; 246 int found=0; 247 248 for (i = 0; !found && mixcomwd_ioports[i] != 0; i++) { 249 watchdog_port = mixcomwd_checkcard(mixcomwd_ioports[i]); 250 if (watchdog_port) { 251 found = 1; 252 } 253 } 254 255 /* The FlashCOM card can be set up at 0x300 -> 0x378, in 0x8 jumps */ 256 for (i = 0x300; !found && i < 0x380; i+=0x8) { 257 watchdog_port = flashcom_checkcard(i); 258 if (watchdog_port) { 259 found = 1; 260 } 261 } 262 263 if (!found) { 264 printk("mixcomwd: No card detected, or port not available.\n"); 265 return -ENODEV; 266 } 267 268 ret = misc_register(&mixcomwd_miscdev); 269 if (ret) 270 { 271 release_region(watchdog_port, 1); 272 return ret; 273 } 274 275 printk(KERN_INFO "MixCOM watchdog driver v%s, watchdog port at 0x%3x\n",VERSION,watchdog_port); 276 277 return 0; 278} 279 280static void __exit mixcomwd_exit(void) 281{ 282 if (!nowayout) { 283 if(mixcomwd_timer_alive) { 284 printk(KERN_WARNING "mixcomwd: I quit now, hardware will" 285 " probably reboot!\n"); 286 del_timer_sync(&mixcomwd_timer); 287 mixcomwd_timer_alive=0; 288 } 289 } 290 release_region(watchdog_port,1); 291 misc_deregister(&mixcomwd_miscdev); 292} 293 294module_init(mixcomwd_init); 295module_exit(mixcomwd_exit); 296 297MODULE_AUTHOR("Gergely Madarasz <gorgo@itc.hu>"); 298MODULE_DESCRIPTION("MixCom Watchdog driver"); 299MODULE_LICENSE("GPL"); 300MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR); 301