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 33 * CONFIG_WATCHDOG_NOWAYOUT 34 * 35 * Version 0.6 (2002/04/12): Rob Radez <rob@osinvestor.com> 36 * - make mixcomwd_opened unsigned, 37 * removed lock_kernel/unlock_kernel from mixcomwd_release, 38 * modified ioctl a bit to conform to API 39 * 40 */ 41 42 #define VERSION "0.6" 43 #define WATCHDOG_NAME "mixcomwd" 44 #define PFX WATCHDOG_NAME ": " 45 46 #include <linux/module.h> 47 #include <linux/moduleparam.h> 48 #include <linux/types.h> 49 #include <linux/miscdevice.h> 50 #include <linux/ioport.h> 51 #include <linux/watchdog.h> 52 #include <linux/fs.h> 53 #include <linux/reboot.h> 54 #include <linux/init.h> 55 #include <linux/jiffies.h> 56 #include <linux/timer.h> 57 #include <linux/uaccess.h> 58 #include <linux/io.h> 59 60 /* 61 * We have two types of cards that can be probed: 62 * 1) The Mixcom cards: these cards can be found at addresses 63 * 0x180, 0x280, 0x380 with an additional offset of 0xc10. 64 * (Or 0xd90, 0xe90, 0xf90). 65 * 2) The FlashCOM cards: these cards can be set up at 66 * 0x300 -> 0x378, in 0x8 jumps with an offset of 0x04. 67 * (Or 0x304 -> 0x37c in 0x8 jumps). 68 * Each card has it's own ID. 69 */ 70 #define MIXCOM_ID 0x11 71 #define FLASHCOM_ID 0x18 72 static struct { 73 int ioport; 74 int id; 75 } mixcomwd_io_info[] __devinitdata = { 76 /* The Mixcom cards */ 77 {0x0d90, MIXCOM_ID}, 78 {0x0e90, MIXCOM_ID}, 79 {0x0f90, MIXCOM_ID}, 80 /* The FlashCOM cards */ 81 {0x0304, FLASHCOM_ID}, 82 {0x030c, FLASHCOM_ID}, 83 {0x0314, FLASHCOM_ID}, 84 {0x031c, FLASHCOM_ID}, 85 {0x0324, FLASHCOM_ID}, 86 {0x032c, FLASHCOM_ID}, 87 {0x0334, FLASHCOM_ID}, 88 {0x033c, FLASHCOM_ID}, 89 {0x0344, FLASHCOM_ID}, 90 {0x034c, FLASHCOM_ID}, 91 {0x0354, FLASHCOM_ID}, 92 {0x035c, FLASHCOM_ID}, 93 {0x0364, FLASHCOM_ID}, 94 {0x036c, FLASHCOM_ID}, 95 {0x0374, FLASHCOM_ID}, 96 {0x037c, FLASHCOM_ID}, 97 /* The end of the list */ 98 {0x0000, 0}, 99 }; 100 101 static void mixcomwd_timerfun(unsigned long d); 102 103 static unsigned long mixcomwd_opened; /* long req'd for setbit --RR */ 104 105 static int watchdog_port; 106 static int mixcomwd_timer_alive; 107 static DEFINE_TIMER(mixcomwd_timer, mixcomwd_timerfun, 0, 0); 108 static char expect_close; 109 110 static int nowayout = WATCHDOG_NOWAYOUT; 111 module_param(nowayout, int, 0); 112 MODULE_PARM_DESC(nowayout, 113 "Watchdog cannot be stopped once started (default=" 114 __MODULE_STRING(WATCHDOG_NOWAYOUT) ")"); 115 116 static void mixcomwd_ping(void) 117 { 118 outb_p(55, watchdog_port); 119 return; 120 } 121 122 static void mixcomwd_timerfun(unsigned long d) 123 { 124 mixcomwd_ping(); 125 mod_timer(&mixcomwd_timer, jiffies + 5 * HZ); 126 } 127 128 /* 129 * Allow only one person to hold it open 130 */ 131 132 static int mixcomwd_open(struct inode *inode, struct file *file) 133 { 134 if (test_and_set_bit(0, &mixcomwd_opened)) 135 return -EBUSY; 136 137 mixcomwd_ping(); 138 139 if (nowayout) 140 /* 141 * fops_get() code via open() has already done 142 * a try_module_get() so it is safe to do the 143 * __module_get(). 144 */ 145 __module_get(THIS_MODULE); 146 else { 147 if (mixcomwd_timer_alive) { 148 del_timer(&mixcomwd_timer); 149 mixcomwd_timer_alive = 0; 150 } 151 } 152 return nonseekable_open(inode, file); 153 } 154 155 static int mixcomwd_release(struct inode *inode, struct file *file) 156 { 157 if (expect_close == 42) { 158 if (mixcomwd_timer_alive) { 159 printk(KERN_ERR PFX 160 "release called while internal timer alive"); 161 return -EBUSY; 162 } 163 mixcomwd_timer_alive = 1; 164 mod_timer(&mixcomwd_timer, jiffies + 5 * HZ); 165 } else 166 printk(KERN_CRIT PFX 167 "WDT device closed unexpectedly. WDT will not stop!\n"); 168 169 clear_bit(0, &mixcomwd_opened); 170 expect_close = 0; 171 return 0; 172 } 173 174 175 static ssize_t mixcomwd_write(struct file *file, const char __user *data, 176 size_t len, loff_t *ppos) 177 { 178 if (len) { 179 if (!nowayout) { 180 size_t i; 181 182 /* In case it was set long ago */ 183 expect_close = 0; 184 185 for (i = 0; i != len; i++) { 186 char c; 187 if (get_user(c, data + i)) 188 return -EFAULT; 189 if (c == 'V') 190 expect_close = 42; 191 } 192 } 193 mixcomwd_ping(); 194 } 195 return len; 196 } 197 198 static long mixcomwd_ioctl(struct file *file, 199 unsigned int cmd, unsigned long arg) 200 { 201 void __user *argp = (void __user *)arg; 202 int __user *p = argp; 203 int status; 204 static const struct watchdog_info ident = { 205 .options = WDIOF_KEEPALIVEPING | WDIOF_MAGICCLOSE, 206 .firmware_version = 1, 207 .identity = "MixCOM watchdog", 208 }; 209 210 switch (cmd) { 211 case WDIOC_GETSUPPORT: 212 if (copy_to_user(argp, &ident, sizeof(ident))) 213 return -EFAULT; 214 break; 215 case WDIOC_GETSTATUS: 216 status = mixcomwd_opened; 217 if (!nowayout) 218 status |= mixcomwd_timer_alive; 219 return put_user(status, p); 220 case WDIOC_GETBOOTSTATUS: 221 return put_user(0, p); 222 case WDIOC_KEEPALIVE: 223 mixcomwd_ping(); 224 break; 225 default: 226 return -ENOTTY; 227 } 228 return 0; 229 } 230 231 static const struct file_operations mixcomwd_fops = { 232 .owner = THIS_MODULE, 233 .llseek = no_llseek, 234 .write = mixcomwd_write, 235 .unlocked_ioctl = mixcomwd_ioctl, 236 .open = mixcomwd_open, 237 .release = mixcomwd_release, 238 }; 239 240 static struct miscdevice mixcomwd_miscdev = { 241 .minor = WATCHDOG_MINOR, 242 .name = "watchdog", 243 .fops = &mixcomwd_fops, 244 }; 245 246 static int __init checkcard(int port, int card_id) 247 { 248 int id; 249 250 if (!request_region(port, 1, "MixCOM watchdog")) 251 return 0; 252 253 id = inb_p(port); 254 if (card_id == MIXCOM_ID) 255 id &= 0x3f; 256 257 if (id != card_id) { 258 release_region(port, 1); 259 return 0; 260 } 261 return 1; 262 } 263 264 static int __init mixcomwd_init(void) 265 { 266 int i, ret, found = 0; 267 268 for (i = 0; !found && mixcomwd_io_info[i].ioport != 0; i++) { 269 if (checkcard(mixcomwd_io_info[i].ioport, 270 mixcomwd_io_info[i].id)) { 271 found = 1; 272 watchdog_port = mixcomwd_io_info[i].ioport; 273 } 274 } 275 276 if (!found) { 277 printk(KERN_ERR PFX 278 "No card detected, or port not available.\n"); 279 return -ENODEV; 280 } 281 282 ret = misc_register(&mixcomwd_miscdev); 283 if (ret) { 284 printk(KERN_ERR PFX 285 "cannot register miscdev on minor=%d (err=%d)\n", 286 WATCHDOG_MINOR, ret); 287 goto error_misc_register_watchdog; 288 } 289 290 printk(KERN_INFO 291 "MixCOM watchdog driver v%s, watchdog port at 0x%3x\n", 292 VERSION, watchdog_port); 293 294 return 0; 295 296 error_misc_register_watchdog: 297 release_region(watchdog_port, 1); 298 watchdog_port = 0x0000; 299 return ret; 300 } 301 302 static void __exit mixcomwd_exit(void) 303 { 304 if (!nowayout) { 305 if (mixcomwd_timer_alive) { 306 printk(KERN_WARNING PFX "I quit now, hardware will" 307 " probably reboot!\n"); 308 del_timer_sync(&mixcomwd_timer); 309 mixcomwd_timer_alive = 0; 310 } 311 } 312 misc_deregister(&mixcomwd_miscdev); 313 release_region(watchdog_port, 1); 314 } 315 316 module_init(mixcomwd_init); 317 module_exit(mixcomwd_exit); 318 319 MODULE_AUTHOR("Gergely Madarasz <gorgo@itc.hu>"); 320 MODULE_DESCRIPTION("MixCom Watchdog driver"); 321 MODULE_VERSION(VERSION); 322 MODULE_LICENSE("GPL"); 323 MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR); 324