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/config.h>
40 #include <linux/types.h>
41 #include <linux/kernel.h>
42 #include <linux/fs.h>
43 #include <linux/mm.h>
44 #include <linux/miscdevice.h>
45 #include <linux/ioport.h>
46 #include <linux/watchdog.h>
47 #include <linux/reboot.h>
48 #include <linux/init.h>
49 #include <linux/smp_lock.h>
50 #include <asm/uaccess.h>
51 #include <asm/io.h>
52
53 static int mixcomwd_ioports[] = { 0x180, 0x280, 0x380, 0x000 };
54
55 #define MIXCOM_WATCHDOG_OFFSET 0xc10
56 #define MIXCOM_ID 0x11
57 #define FLASHCOM_WATCHDOG_OFFSET 0x4
58 #define FLASHCOM_ID 0x18
59
60 static long mixcomwd_opened; /* long req'd for setbit --RR */
61
62 static int watchdog_port;
63
64 static int mixcomwd_timer_alive;
65 static struct timer_list mixcomwd_timer;
66 static int expect_close = 0;
67
68 #ifdef CONFIG_WATCHDOG_NOWAYOUT
69 static int nowayout = 1;
70 #else
71 static int nowayout = 0;
72 #endif
73
74 MODULE_PARM(nowayout,"i");
75 MODULE_PARM_DESC(nowayout, "Watchdog cannot be stopped once started (default=CONFIG_WATCHDOG_NOWAYOUT)");
76
mixcomwd_ping(void)77 static void mixcomwd_ping(void)
78 {
79 outb_p(55,watchdog_port);
80 return;
81 }
82
mixcomwd_timerfun(unsigned long d)83 static void mixcomwd_timerfun(unsigned long d)
84 {
85 mixcomwd_ping();
86
87 mod_timer(&mixcomwd_timer,jiffies+ 5*HZ);
88 }
89
90 /*
91 * Allow only one person to hold it open
92 */
93
mixcomwd_open(struct inode * inode,struct file * file)94 static int mixcomwd_open(struct inode *inode, struct file *file)
95 {
96 if(test_and_set_bit(0,&mixcomwd_opened)) {
97 return -EBUSY;
98 }
99 mixcomwd_ping();
100
101 if (nowayout) {
102 MOD_INC_USE_COUNT;
103 }
104 if(mixcomwd_timer_alive) {
105 del_timer(&mixcomwd_timer);
106 mixcomwd_timer_alive=0;
107 }
108 return 0;
109 }
110
mixcomwd_release(struct inode * inode,struct file * file)111 static int mixcomwd_release(struct inode *inode, struct file *file)
112 {
113
114 lock_kernel();
115 if (expect_close) {
116 if(mixcomwd_timer_alive) {
117 printk(KERN_ERR "mixcomwd: release called while internal timer alive");
118 unlock_kernel();
119 return -EBUSY;
120 }
121 init_timer(&mixcomwd_timer);
122 mixcomwd_timer.expires=jiffies + 5 * HZ;
123 mixcomwd_timer.function=mixcomwd_timerfun;
124 mixcomwd_timer.data=0;
125 mixcomwd_timer_alive=1;
126 add_timer(&mixcomwd_timer);
127 } else {
128 printk(KERN_CRIT "mixcomwd: WDT device closed unexpectedly. WDT will not stop!\n");
129 }
130
131 clear_bit(0,&mixcomwd_opened);
132 unlock_kernel();
133 return 0;
134 }
135
136
mixcomwd_write(struct file * file,const char * data,size_t len,loff_t * ppos)137 static ssize_t mixcomwd_write(struct file *file, const char *data, size_t len, loff_t *ppos)
138 {
139 if (ppos != &file->f_pos) {
140 return -ESPIPE;
141 }
142
143 if(len)
144 {
145 if (!nowayout) {
146 size_t i;
147
148 /* In case it was set long ago */
149 expect_close = 0;
150
151 for (i = 0; i != len; i++) {
152 char c;
153 if (get_user(c, data + i))
154 return -EFAULT;
155 if (c == 'V')
156 expect_close = 1;
157 }
158 }
159 mixcomwd_ping();
160 return 1;
161 }
162 return 0;
163 }
164
mixcomwd_ioctl(struct inode * inode,struct file * file,unsigned int cmd,unsigned long arg)165 static int mixcomwd_ioctl(struct inode *inode, struct file *file,
166 unsigned int cmd, unsigned long arg)
167 {
168 int status;
169 static struct watchdog_info ident = {
170 WDIOF_KEEPALIVEPING | WDIOF_MAGICCLOSE,
171 1, "MixCOM watchdog"
172 };
173
174 switch(cmd)
175 {
176 case WDIOC_GETSTATUS:
177 status=mixcomwd_opened;
178 if (!nowayout) {
179 status|=mixcomwd_timer_alive;
180 }
181 if (copy_to_user((int *)arg, &status, sizeof(int))) {
182 return -EFAULT;
183 }
184 break;
185 case WDIOC_GETSUPPORT:
186 if (copy_to_user((struct watchdog_info *)arg, &ident,
187 sizeof(ident))) {
188 return -EFAULT;
189 }
190 break;
191 case WDIOC_KEEPALIVE:
192 mixcomwd_ping();
193 break;
194 default:
195 return -ENOTTY;
196 }
197 return 0;
198 }
199
200 static struct file_operations mixcomwd_fops=
201 {
202 owner: THIS_MODULE,
203 write: mixcomwd_write,
204 ioctl: mixcomwd_ioctl,
205 open: mixcomwd_open,
206 release: mixcomwd_release,
207 };
208
209 static struct miscdevice mixcomwd_miscdev=
210 {
211 WATCHDOG_MINOR,
212 "watchdog",
213 &mixcomwd_fops
214 };
215
mixcomwd_checkcard(int port)216 static int __init mixcomwd_checkcard(int port)
217 {
218 int id;
219
220 if(check_region(port+MIXCOM_WATCHDOG_OFFSET,1)) {
221 return 0;
222 }
223
224 id=inb_p(port + MIXCOM_WATCHDOG_OFFSET) & 0x3f;
225 if(id!=MIXCOM_ID) {
226 return 0;
227 }
228 return 1;
229 }
230
flashcom_checkcard(int port)231 static int __init flashcom_checkcard(int port)
232 {
233 int id;
234
235 if(check_region(port + FLASHCOM_WATCHDOG_OFFSET,1)) {
236 return 0;
237 }
238
239 id=inb_p(port + FLASHCOM_WATCHDOG_OFFSET);
240 if(id!=FLASHCOM_ID) {
241 return 0;
242 }
243 return 1;
244 }
245
mixcomwd_init(void)246 static int __init mixcomwd_init(void)
247 {
248 int i;
249 int ret;
250 int found=0;
251
252 for (i = 0; !found && mixcomwd_ioports[i] != 0; i++) {
253 if (mixcomwd_checkcard(mixcomwd_ioports[i])) {
254 found = 1;
255 watchdog_port = mixcomwd_ioports[i] + MIXCOM_WATCHDOG_OFFSET;
256 }
257 }
258
259 /* The FlashCOM card can be set up at 0x300 -> 0x378, in 0x8 jumps */
260 for (i = 0x300; !found && i < 0x380; i+=0x8) {
261 if (flashcom_checkcard(i)) {
262 found = 1;
263 watchdog_port = i + FLASHCOM_WATCHDOG_OFFSET;
264 }
265 }
266
267 if (!found) {
268 printk("mixcomwd: No card detected, or port not available.\n");
269 return -ENODEV;
270 }
271
272 request_region(watchdog_port,1,"MixCOM watchdog");
273
274 ret = misc_register(&mixcomwd_miscdev);
275 if (ret)
276 return ret;
277
278 printk(KERN_INFO "MixCOM watchdog driver v%s, watchdog port at 0x%3x\n",VERSION,watchdog_port);
279
280 return 0;
281 }
282
mixcomwd_exit(void)283 static void __exit mixcomwd_exit(void)
284 {
285 if (!nowayout) {
286 if(mixcomwd_timer_alive) {
287 printk(KERN_WARNING "mixcomwd: I quit now, hardware will"
288 " probably reboot!\n");
289 del_timer(&mixcomwd_timer);
290 mixcomwd_timer_alive=0;
291 }
292 }
293 release_region(watchdog_port,1);
294 misc_deregister(&mixcomwd_miscdev);
295 }
296
297 module_init(mixcomwd_init);
298 module_exit(mixcomwd_exit);
299
300 MODULE_LICENSE("GPL");
301 EXPORT_NO_SYMBOLS;
302