1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
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
63
64
65
66
67
68
69
70
71#define MIXCOM_ID 0x11
72#define FLASHCOM_ID 0x18
73static struct {
74 int ioport;
75 int id;
76} mixcomwd_io_info[] = {
77
78 {0x0d90, MIXCOM_ID},
79 {0x0e90, MIXCOM_ID},
80 {0x0f90, MIXCOM_ID},
81
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
99 {0x0000, 0},
100};
101
102static void mixcomwd_timerfun(struct timer_list *unused);
103
104static unsigned long mixcomwd_opened;
105
106static int watchdog_port;
107static int mixcomwd_timer_alive;
108static DEFINE_TIMER(mixcomwd_timer, mixcomwd_timerfun);
109static char expect_close;
110
111static bool nowayout = WATCHDOG_NOWAYOUT;
112module_param(nowayout, bool, 0);
113MODULE_PARM_DESC(nowayout,
114 "Watchdog cannot be stopped once started (default="
115 __MODULE_STRING(WATCHDOG_NOWAYOUT) ")");
116
117static void mixcomwd_ping(void)
118{
119 outb_p(55, watchdog_port);
120 return;
121}
122
123static void mixcomwd_timerfun(struct timer_list *unused)
124{
125 mixcomwd_ping();
126 mod_timer(&mixcomwd_timer, jiffies + 5 * HZ);
127}
128
129
130
131
132
133static 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
143
144
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
156static 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
174static 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
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
197static 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
230static 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
239static struct miscdevice mixcomwd_miscdev = {
240 .minor = WATCHDOG_MINOR,
241 .name = "watchdog",
242 .fops = &mixcomwd_fops,
243};
244
245static 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
263static 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
292error_misc_register_watchdog:
293 release_region(watchdog_port, 1);
294 watchdog_port = 0x0000;
295 return ret;
296}
297
298static 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
311module_init(mixcomwd_init);
312module_exit(mixcomwd_exit);
313
314MODULE_AUTHOR("Gergely Madarasz <gorgo@itc.hu>");
315MODULE_DESCRIPTION("MixCom Watchdog driver");
316MODULE_VERSION(VERSION);
317MODULE_LICENSE("GPL");
318