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