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 * Version 0.6 (2002/04/12): Rob Radez <rob@osinvestor.com> 35 * - make mixcomwd_opened unsigned, 36 * removed lock_kernel/unlock_kernel from mixcomwd_release, 37 * modified ioctl a bit to conform to API 38 * 39 */ 40 41 #define VERSION "0.6" 42 #define WATCHDOG_NAME "mixcomwd" 43 #define PFX WATCHDOG_NAME ": " 44 45 #include <linux/module.h> 46 #include <linux/moduleparam.h> 47 #include <linux/types.h> 48 #include <linux/miscdevice.h> 49 #include <linux/ioport.h> 50 #include <linux/watchdog.h> 51 #include <linux/fs.h> 52 #include <linux/reboot.h> 53 #include <linux/init.h> 54 #include <linux/jiffies.h> 55 #include <linux/timer.h> 56 #include <asm/uaccess.h> 57 #include <asm/io.h> 58 59 /* 60 * We have two types of cards that can be probed: 61 * 1) The Mixcom cards: these cards can be found at addresses 62 * 0x180, 0x280, 0x380 with an additional offset of 0xc10. 63 * (Or 0xd90, 0xe90, 0xf90). 64 * 2) The FlashCOM cards: these cards can be set up at 65 * 0x300 -> 0x378, in 0x8 jumps with an offset of 0x04. 66 * (Or 0x304 -> 0x37c in 0x8 jumps). 67 * Each card has it's own ID. 68 */ 69 #define MIXCOM_ID 0x11 70 #define FLASHCOM_ID 0x18 71 static struct { 72 int ioport; 73 int id; 74 } mixcomwd_io_info[] __devinitdata = { 75 /* The Mixcom cards */ 76 {0x0d90, MIXCOM_ID}, 77 {0x0e90, MIXCOM_ID}, 78 {0x0f90, MIXCOM_ID}, 79 /* The FlashCOM cards */ 80 {0x0304, FLASHCOM_ID}, 81 {0x030c, FLASHCOM_ID}, 82 {0x0314, FLASHCOM_ID}, 83 {0x031c, FLASHCOM_ID}, 84 {0x0324, FLASHCOM_ID}, 85 {0x032c, FLASHCOM_ID}, 86 {0x0334, FLASHCOM_ID}, 87 {0x033c, FLASHCOM_ID}, 88 {0x0344, FLASHCOM_ID}, 89 {0x034c, FLASHCOM_ID}, 90 {0x0354, FLASHCOM_ID}, 91 {0x035c, FLASHCOM_ID}, 92 {0x0364, FLASHCOM_ID}, 93 {0x036c, FLASHCOM_ID}, 94 {0x0374, FLASHCOM_ID}, 95 {0x037c, FLASHCOM_ID}, 96 /* The end of the list */ 97 {0x0000, 0}, 98 }; 99 100 static void mixcomwd_timerfun(unsigned long d); 101 102 static unsigned long mixcomwd_opened; /* long req'd for setbit --RR */ 103 104 static int watchdog_port; 105 static int mixcomwd_timer_alive; 106 static DEFINE_TIMER(mixcomwd_timer, mixcomwd_timerfun, 0, 0); 107 static char expect_close; 108 109 static int nowayout = WATCHDOG_NOWAYOUT; 110 module_param(nowayout, int, 0); 111 MODULE_PARM_DESC(nowayout, "Watchdog cannot be stopped once started (default=" __MODULE_STRING(WATCHDOG_NOWAYOUT) ")"); 112 113 static void mixcomwd_ping(void) 114 { 115 outb_p(55,watchdog_port); 116 return; 117 } 118 119 static void mixcomwd_timerfun(unsigned long d) 120 { 121 mixcomwd_ping(); 122 123 mod_timer(&mixcomwd_timer, jiffies + 5 * HZ); 124 } 125 126 /* 127 * Allow only one person to hold it open 128 */ 129 130 static int mixcomwd_open(struct inode *inode, struct file *file) 131 { 132 if(test_and_set_bit(0,&mixcomwd_opened)) { 133 return -EBUSY; 134 } 135 mixcomwd_ping(); 136 137 if (nowayout) { 138 /* 139 * fops_get() code via open() has already done 140 * a try_module_get() so it is safe to do the 141 * __module_get(). 142 */ 143 __module_get(THIS_MODULE); 144 } else { 145 if(mixcomwd_timer_alive) { 146 del_timer(&mixcomwd_timer); 147 mixcomwd_timer_alive=0; 148 } 149 } 150 return nonseekable_open(inode, file); 151 } 152 153 static int mixcomwd_release(struct inode *inode, struct file *file) 154 { 155 if (expect_close == 42) { 156 if(mixcomwd_timer_alive) { 157 printk(KERN_ERR PFX "release called while internal timer alive"); 158 return -EBUSY; 159 } 160 mixcomwd_timer_alive=1; 161 mod_timer(&mixcomwd_timer, jiffies + 5 * HZ); 162 } else { 163 printk(KERN_CRIT PFX "WDT device closed unexpectedly. WDT will not stop!\n"); 164 } 165 166 clear_bit(0,&mixcomwd_opened); 167 expect_close=0; 168 return 0; 169 } 170 171 172 static ssize_t mixcomwd_write(struct file *file, const char __user *data, size_t len, loff_t *ppos) 173 { 174 if(len) 175 { 176 if (!nowayout) { 177 size_t i; 178 179 /* In case it was set long ago */ 180 expect_close = 0; 181 182 for (i = 0; i != len; i++) { 183 char c; 184 if (get_user(c, data + i)) 185 return -EFAULT; 186 if (c == 'V') 187 expect_close = 42; 188 } 189 } 190 mixcomwd_ping(); 191 } 192 return len; 193 } 194 195 static int mixcomwd_ioctl(struct inode *inode, struct file *file, 196 unsigned int cmd, unsigned long arg) 197 { 198 void __user *argp = (void __user *)arg; 199 int __user *p = argp; 200 int status; 201 static struct watchdog_info ident = { 202 .options = WDIOF_KEEPALIVEPING | WDIOF_MAGICCLOSE, 203 .firmware_version = 1, 204 .identity = "MixCOM watchdog", 205 }; 206 207 switch(cmd) 208 { 209 case WDIOC_GETSTATUS: 210 status=mixcomwd_opened; 211 if (!nowayout) { 212 status|=mixcomwd_timer_alive; 213 } 214 if (copy_to_user(p, &status, sizeof(int))) { 215 return -EFAULT; 216 } 217 break; 218 case WDIOC_GETBOOTSTATUS: 219 if (copy_to_user(p, &status, sizeof(int))) { 220 return -EFAULT; 221 } 222 break; 223 case WDIOC_GETSUPPORT: 224 if (copy_to_user(argp, &ident, sizeof(ident))) { 225 return -EFAULT; 226 } 227 break; 228 case WDIOC_KEEPALIVE: 229 mixcomwd_ping(); 230 break; 231 default: 232 return -ENOTTY; 233 } 234 return 0; 235 } 236 237 static const struct file_operations mixcomwd_fops = { 238 .owner = THIS_MODULE, 239 .llseek = no_llseek, 240 .write = mixcomwd_write, 241 .ioctl = mixcomwd_ioctl, 242 .open = mixcomwd_open, 243 .release = mixcomwd_release, 244 }; 245 246 static struct miscdevice mixcomwd_miscdev = { 247 .minor = WATCHDOG_MINOR, 248 .name = "watchdog", 249 .fops = &mixcomwd_fops, 250 }; 251 252 static int __init checkcard(int port, int card_id) 253 { 254 int id; 255 256 if (!request_region(port, 1, "MixCOM watchdog")) { 257 return 0; 258 } 259 260 id=inb_p(port); 261 if (card_id==MIXCOM_ID) 262 id &= 0x3f; 263 264 if (id!=card_id) { 265 release_region(port, 1); 266 return 0; 267 } 268 return 1; 269 } 270 271 static int __init mixcomwd_init(void) 272 { 273 int i; 274 int ret; 275 int found=0; 276 277 for (i = 0; !found && mixcomwd_io_info[i].ioport != 0; i++) { 278 if (checkcard(mixcomwd_io_info[i].ioport, 279 mixcomwd_io_info[i].id)) { 280 found = 1; 281 watchdog_port = mixcomwd_io_info[i].ioport; 282 } 283 } 284 285 if (!found) { 286 printk(KERN_ERR PFX "No card detected, or port not available.\n"); 287 return -ENODEV; 288 } 289 290 ret = misc_register(&mixcomwd_miscdev); 291 if (ret) 292 { 293 printk(KERN_ERR PFX "cannot register miscdev on minor=%d (err=%d)\n", 294 WATCHDOG_MINOR, ret); 295 goto error_misc_register_watchdog; 296 } 297 298 printk(KERN_INFO "MixCOM watchdog driver v%s, watchdog port at 0x%3x\n", 299 VERSION, watchdog_port); 300 301 return 0; 302 303 error_misc_register_watchdog: 304 release_region(watchdog_port, 1); 305 watchdog_port = 0x0000; 306 return ret; 307 } 308 309 static void __exit mixcomwd_exit(void) 310 { 311 if (!nowayout) { 312 if(mixcomwd_timer_alive) { 313 printk(KERN_WARNING PFX "I quit now, hardware will" 314 " probably reboot!\n"); 315 del_timer_sync(&mixcomwd_timer); 316 mixcomwd_timer_alive=0; 317 } 318 } 319 misc_deregister(&mixcomwd_miscdev); 320 release_region(watchdog_port,1); 321 } 322 323 module_init(mixcomwd_init); 324 module_exit(mixcomwd_exit); 325 326 MODULE_AUTHOR("Gergely Madarasz <gorgo@itc.hu>"); 327 MODULE_DESCRIPTION("MixCom Watchdog driver"); 328 MODULE_VERSION(VERSION); 329 MODULE_LICENSE("GPL"); 330 MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR); 331