Commit | Line | Data |
---|---|---|
1da177e4 LT |
1 | /* |
2 | * W83877F Computer Watchdog Timer driver | |
3 | * | |
4 | * Based on acquirewdt.c by Alan Cox, | |
5 | * and sbc60xxwdt.c by Jakob Oestergaard <jakob@unthought.net> | |
6 | * | |
7 | * This program is free software; you can redistribute it and/or | |
8 | * modify it under the terms of the GNU General Public License | |
9 | * as published by the Free Software Foundation; either version | |
10 | * 2 of the License, or (at your option) any later version. | |
11 | * | |
12 | * The authors do NOT admit liability nor provide warranty for | |
13 | * any of this software. This material is provided "AS-IS" in | |
14 | * the hope that it may be useful for others. | |
15 | * | |
16 | * (c) Copyright 2001 Scott Jennings <linuxdrivers@oro.net> | |
17 | * | |
18 | * 4/19 - 2001 [Initial revision] | |
19 | * 9/27 - 2001 Added spinlocking | |
20 | * 4/12 - 2002 [rob@osinvestor.com] Eliminate extra comments | |
21 | * Eliminate fop_read | |
22 | * Eliminate extra spin_unlock | |
23 | * Added KERN_* tags to printks | |
24 | * add CONFIG_WATCHDOG_NOWAYOUT support | |
25 | * fix possible wdt_is_open race | |
c1cfd1a2 AC |
26 | * changed watchdog_info to correctly reflect what |
27 | * the driver offers | |
28 | * added WDIOC_GETSTATUS, WDIOC_GETBOOTSTATUS, | |
29 | * WDIOC_SETTIMEOUT, | |
1da177e4 LT |
30 | * WDIOC_GETTIMEOUT, and WDIOC_SETOPTIONS ioctls |
31 | * 09/8 - 2003 [wim@iguana.be] cleanup of trailing spaces | |
32 | * added extra printk's for startup problems | |
33 | * use module_param | |
c1cfd1a2 AC |
34 | * made timeout (the emulated heartbeat) a |
35 | * module_param | |
1da177e4 LT |
36 | * made the keepalive ping an internal subroutine |
37 | * | |
38 | * This WDT driver is different from most other Linux WDT | |
39 | * drivers in that the driver will ping the watchdog by itself, | |
40 | * because this particular WDT has a very short timeout (1.6 | |
41 | * seconds) and it would be insane to count on any userspace | |
42 | * daemon always getting scheduled within that time frame. | |
43 | */ | |
44 | ||
45 | #include <linux/module.h> | |
46 | #include <linux/moduleparam.h> | |
47 | #include <linux/types.h> | |
48 | #include <linux/timer.h> | |
49 | #include <linux/jiffies.h> | |
50 | #include <linux/miscdevice.h> | |
51 | #include <linux/watchdog.h> | |
52 | #include <linux/fs.h> | |
53 | #include <linux/ioport.h> | |
54 | #include <linux/notifier.h> | |
55 | #include <linux/reboot.h> | |
56 | #include <linux/init.h> | |
c1cfd1a2 AC |
57 | #include <linux/io.h> |
58 | #include <linux/uaccess.h> | |
1da177e4 LT |
59 | #include <asm/system.h> |
60 | ||
61 | #define OUR_NAME "w83877f_wdt" | |
62 | #define PFX OUR_NAME ": " | |
63 | ||
64 | #define ENABLE_W83877F_PORT 0x3F0 | |
65 | #define ENABLE_W83877F 0x87 | |
66 | #define DISABLE_W83877F 0xAA | |
67 | #define WDT_PING 0x443 | |
68 | #define WDT_REGISTER 0x14 | |
69 | #define WDT_ENABLE 0x9C | |
70 | #define WDT_DISABLE 0x8C | |
71 | ||
72 | /* | |
73 | * The W83877F seems to be fixed at 1.6s timeout (at least on the | |
74 | * EMACS PC-104 board I'm using). If we reset the watchdog every | |
75 | * ~250ms we should be safe. */ | |
76 | ||
77 | #define WDT_INTERVAL (HZ/4+1) | |
78 | ||
79 | /* | |
80 | * We must not require too good response from the userspace daemon. | |
81 | * Here we require the userspace daemon to send us a heartbeat | |
82 | * char to /dev/watchdog every 30 seconds. | |
83 | */ | |
84 | ||
85 | #define WATCHDOG_TIMEOUT 30 /* 30 sec default timeout */ | |
c1cfd1a2 AC |
86 | /* in seconds, will be multiplied by HZ to get seconds to wait for a ping */ |
87 | static int timeout = WATCHDOG_TIMEOUT; | |
1da177e4 | 88 | module_param(timeout, int, 0); |
c1cfd1a2 AC |
89 | MODULE_PARM_DESC(timeout, |
90 | "Watchdog timeout in seconds. (1<=timeout<=3600, default=" | |
91 | __MODULE_STRING(WATCHDOG_TIMEOUT) ")"); | |
1da177e4 LT |
92 | |
93 | ||
4bfdf378 | 94 | static int nowayout = WATCHDOG_NOWAYOUT; |
1da177e4 | 95 | module_param(nowayout, int, 0); |
c1cfd1a2 AC |
96 | MODULE_PARM_DESC(nowayout, |
97 | "Watchdog cannot be stopped once started (default=" | |
98 | __MODULE_STRING(WATCHDOG_NOWAYOUT) ")"); | |
1da177e4 LT |
99 | |
100 | static void wdt_timer_ping(unsigned long); | |
82eb7c50 | 101 | static DEFINE_TIMER(timer, wdt_timer_ping, 0, 0); |
1da177e4 LT |
102 | static unsigned long next_heartbeat; |
103 | static unsigned long wdt_is_open; | |
104 | static char wdt_expect_close; | |
c7dfd0cc | 105 | static DEFINE_SPINLOCK(wdt_spinlock); |
1da177e4 LT |
106 | |
107 | /* | |
108 | * Whack the dog | |
109 | */ | |
110 | ||
111 | static void wdt_timer_ping(unsigned long data) | |
112 | { | |
113 | /* If we got a heartbeat pulse within the WDT_US_INTERVAL | |
114 | * we agree to ping the WDT | |
115 | */ | |
c1cfd1a2 | 116 | if (time_before(jiffies, next_heartbeat)) { |
1da177e4 LT |
117 | /* Ping the WDT */ |
118 | spin_lock(&wdt_spinlock); | |
119 | ||
120 | /* Ping the WDT by reading from WDT_PING */ | |
121 | inb_p(WDT_PING); | |
122 | ||
123 | /* Re-set the timer interval */ | |
82eb7c50 | 124 | mod_timer(&timer, jiffies + WDT_INTERVAL); |
1da177e4 LT |
125 | |
126 | spin_unlock(&wdt_spinlock); | |
127 | ||
c1cfd1a2 AC |
128 | } else |
129 | printk(KERN_WARNING PFX | |
130 | "Heartbeat lost! Will not ping the watchdog\n"); | |
1da177e4 LT |
131 | } |
132 | ||
133 | /* | |
134 | * Utility routines | |
135 | */ | |
136 | ||
137 | static void wdt_change(int writeval) | |
138 | { | |
139 | unsigned long flags; | |
140 | spin_lock_irqsave(&wdt_spinlock, flags); | |
141 | ||
142 | /* buy some time */ | |
143 | inb_p(WDT_PING); | |
144 | ||
145 | /* make W83877F available */ | |
146 | outb_p(ENABLE_W83877F, ENABLE_W83877F_PORT); | |
147 | outb_p(ENABLE_W83877F, ENABLE_W83877F_PORT); | |
148 | ||
149 | /* enable watchdog */ | |
150 | outb_p(WDT_REGISTER, ENABLE_W83877F_PORT); | |
151 | outb_p(writeval, ENABLE_W83877F_PORT+1); | |
152 | ||
153 | /* lock the W8387FF away */ | |
154 | outb_p(DISABLE_W83877F, ENABLE_W83877F_PORT); | |
155 | ||
156 | spin_unlock_irqrestore(&wdt_spinlock, flags); | |
157 | } | |
158 | ||
159 | static void wdt_startup(void) | |
160 | { | |
161 | next_heartbeat = jiffies + (timeout * HZ); | |
162 | ||
163 | /* Start the timer */ | |
82eb7c50 | 164 | mod_timer(&timer, jiffies + WDT_INTERVAL); |
1da177e4 LT |
165 | |
166 | wdt_change(WDT_ENABLE); | |
167 | ||
168 | printk(KERN_INFO PFX "Watchdog timer is now enabled.\n"); | |
169 | } | |
170 | ||
171 | static void wdt_turnoff(void) | |
172 | { | |
173 | /* Stop the timer */ | |
174 | del_timer(&timer); | |
175 | ||
176 | wdt_change(WDT_DISABLE); | |
177 | ||
178 | printk(KERN_INFO PFX "Watchdog timer is now disabled...\n"); | |
179 | } | |
180 | ||
181 | static void wdt_keepalive(void) | |
182 | { | |
183 | /* user land ping */ | |
184 | next_heartbeat = jiffies + (timeout * HZ); | |
185 | } | |
186 | ||
187 | /* | |
188 | * /dev/watchdog handling | |
189 | */ | |
190 | ||
c1cfd1a2 AC |
191 | static ssize_t fop_write(struct file *file, const char __user *buf, |
192 | size_t count, loff_t *ppos) | |
1da177e4 LT |
193 | { |
194 | /* See if we got the magic character 'V' and reload the timer */ | |
c1cfd1a2 AC |
195 | if (count) { |
196 | if (!nowayout) { | |
1da177e4 LT |
197 | size_t ofs; |
198 | ||
c1cfd1a2 AC |
199 | /* note: just in case someone wrote the magic |
200 | character five months ago... */ | |
1da177e4 LT |
201 | wdt_expect_close = 0; |
202 | ||
c1cfd1a2 AC |
203 | /* scan to see whether or not we got the |
204 | magic character */ | |
205 | for (ofs = 0; ofs != count; ofs++) { | |
1da177e4 LT |
206 | char c; |
207 | if (get_user(c, buf + ofs)) | |
208 | return -EFAULT; | |
209 | if (c == 'V') | |
210 | wdt_expect_close = 42; | |
211 | } | |
212 | } | |
213 | ||
214 | /* someone wrote to us, we should restart timer */ | |
215 | wdt_keepalive(); | |
216 | } | |
217 | return count; | |
218 | } | |
219 | ||
c1cfd1a2 | 220 | static int fop_open(struct inode *inode, struct file *file) |
1da177e4 LT |
221 | { |
222 | /* Just in case we're already talking to someone... */ | |
c1cfd1a2 | 223 | if (test_and_set_bit(0, &wdt_is_open)) |
1da177e4 LT |
224 | return -EBUSY; |
225 | ||
226 | /* Good, fire up the show */ | |
227 | wdt_startup(); | |
228 | return nonseekable_open(inode, file); | |
229 | } | |
230 | ||
c1cfd1a2 | 231 | static int fop_close(struct inode *inode, struct file *file) |
1da177e4 | 232 | { |
c1cfd1a2 | 233 | if (wdt_expect_close == 42) |
1da177e4 LT |
234 | wdt_turnoff(); |
235 | else { | |
236 | del_timer(&timer); | |
c1cfd1a2 AC |
237 | printk(KERN_CRIT PFX |
238 | "device file closed unexpectedly. Will not stop the WDT!\n"); | |
1da177e4 LT |
239 | } |
240 | clear_bit(0, &wdt_is_open); | |
241 | wdt_expect_close = 0; | |
242 | return 0; | |
243 | } | |
244 | ||
c1cfd1a2 | 245 | static long fop_ioctl(struct file *file, unsigned int cmd, unsigned long arg) |
1da177e4 LT |
246 | { |
247 | void __user *argp = (void __user *)arg; | |
248 | int __user *p = argp; | |
c1cfd1a2 AC |
249 | static const struct watchdog_info ident = { |
250 | .options = WDIOF_KEEPALIVEPING | WDIOF_SETTIMEOUT | |
251 | | WDIOF_MAGICCLOSE, | |
1da177e4 LT |
252 | .firmware_version = 1, |
253 | .identity = "W83877F", | |
254 | }; | |
255 | ||
c1cfd1a2 | 256 | switch (cmd) { |
c1cfd1a2 AC |
257 | case WDIOC_GETSUPPORT: |
258 | return copy_to_user(argp, &ident, sizeof(ident)) ? -EFAULT : 0; | |
259 | case WDIOC_GETSTATUS: | |
260 | case WDIOC_GETBOOTSTATUS: | |
261 | return put_user(0, p); | |
c1cfd1a2 | 262 | case WDIOC_SETOPTIONS: |
1da177e4 | 263 | { |
c1cfd1a2 | 264 | int new_options, retval = -EINVAL; |
1da177e4 | 265 | |
c1cfd1a2 AC |
266 | if (get_user(new_options, p)) |
267 | return -EFAULT; | |
1da177e4 | 268 | |
c1cfd1a2 AC |
269 | if (new_options & WDIOS_DISABLECARD) { |
270 | wdt_turnoff(); | |
271 | retval = 0; | |
1da177e4 | 272 | } |
1da177e4 | 273 | |
c1cfd1a2 AC |
274 | if (new_options & WDIOS_ENABLECARD) { |
275 | wdt_startup(); | |
276 | retval = 0; | |
277 | } | |
1da177e4 | 278 | |
c1cfd1a2 AC |
279 | return retval; |
280 | } | |
0c06090c WVS |
281 | case WDIOC_KEEPALIVE: |
282 | wdt_keepalive(); | |
283 | return 0; | |
c1cfd1a2 AC |
284 | case WDIOC_SETTIMEOUT: |
285 | { | |
286 | int new_timeout; | |
1da177e4 | 287 | |
c1cfd1a2 AC |
288 | if (get_user(new_timeout, p)) |
289 | return -EFAULT; | |
290 | ||
291 | /* arbitrary upper limit */ | |
292 | if (new_timeout < 1 || new_timeout > 3600) | |
293 | return -EINVAL; | |
294 | ||
295 | timeout = new_timeout; | |
296 | wdt_keepalive(); | |
297 | /* Fall through */ | |
298 | } | |
299 | case WDIOC_GETTIMEOUT: | |
300 | return put_user(timeout, p); | |
0c06090c WVS |
301 | default: |
302 | return -ENOTTY; | |
1da177e4 LT |
303 | } |
304 | } | |
305 | ||
62322d25 | 306 | static const struct file_operations wdt_fops = { |
1da177e4 LT |
307 | .owner = THIS_MODULE, |
308 | .llseek = no_llseek, | |
309 | .write = fop_write, | |
310 | .open = fop_open, | |
311 | .release = fop_close, | |
c1cfd1a2 | 312 | .unlocked_ioctl = fop_ioctl, |
1da177e4 LT |
313 | }; |
314 | ||
315 | static struct miscdevice wdt_miscdev = { | |
316 | .minor = WATCHDOG_MINOR, | |
317 | .name = "watchdog", | |
318 | .fops = &wdt_fops, | |
319 | }; | |
320 | ||
321 | /* | |
322 | * Notifier for system down | |
323 | */ | |
324 | ||
325 | static int wdt_notify_sys(struct notifier_block *this, unsigned long code, | |
326 | void *unused) | |
327 | { | |
c1cfd1a2 | 328 | if (code == SYS_DOWN || code == SYS_HALT) |
1da177e4 LT |
329 | wdt_turnoff(); |
330 | return NOTIFY_DONE; | |
331 | } | |
332 | ||
333 | /* | |
334 | * The WDT needs to learn about soft shutdowns in order to | |
335 | * turn the timebomb registers off. | |
336 | */ | |
337 | ||
c1cfd1a2 | 338 | static struct notifier_block wdt_notifier = { |
1da177e4 LT |
339 | .notifier_call = wdt_notify_sys, |
340 | }; | |
341 | ||
342 | static void __exit w83877f_wdt_unload(void) | |
343 | { | |
344 | wdt_turnoff(); | |
345 | ||
346 | /* Deregister */ | |
347 | misc_deregister(&wdt_miscdev); | |
348 | ||
349 | unregister_reboot_notifier(&wdt_notifier); | |
c1cfd1a2 AC |
350 | release_region(WDT_PING, 1); |
351 | release_region(ENABLE_W83877F_PORT, 2); | |
1da177e4 LT |
352 | } |
353 | ||
354 | static int __init w83877f_wdt_init(void) | |
355 | { | |
356 | int rc = -EBUSY; | |
357 | ||
c1cfd1a2 | 358 | if (timeout < 1 || timeout > 3600) { /* arbitrary upper limit */ |
1da177e4 | 359 | timeout = WATCHDOG_TIMEOUT; |
c1cfd1a2 AC |
360 | printk(KERN_INFO PFX |
361 | "timeout value must be 1 <= x <= 3600, using %d\n", | |
362 | timeout); | |
1da177e4 LT |
363 | } |
364 | ||
c1cfd1a2 | 365 | if (!request_region(ENABLE_W83877F_PORT, 2, "W83877F WDT")) { |
1da177e4 LT |
366 | printk(KERN_ERR PFX "I/O address 0x%04x already in use\n", |
367 | ENABLE_W83877F_PORT); | |
368 | rc = -EIO; | |
369 | goto err_out; | |
370 | } | |
371 | ||
c1cfd1a2 | 372 | if (!request_region(WDT_PING, 1, "W8387FF WDT")) { |
1da177e4 LT |
373 | printk(KERN_ERR PFX "I/O address 0x%04x already in use\n", |
374 | WDT_PING); | |
375 | rc = -EIO; | |
376 | goto err_out_region1; | |
377 | } | |
378 | ||
c6cb13ae | 379 | rc = register_reboot_notifier(&wdt_notifier); |
c1cfd1a2 AC |
380 | if (rc) { |
381 | printk(KERN_ERR PFX | |
382 | "cannot register reboot notifier (err=%d)\n", rc); | |
1da177e4 LT |
383 | goto err_out_region2; |
384 | } | |
385 | ||
c6cb13ae | 386 | rc = misc_register(&wdt_miscdev); |
c1cfd1a2 AC |
387 | if (rc) { |
388 | printk(KERN_ERR PFX | |
389 | "cannot register miscdev on minor=%d (err=%d)\n", | |
390 | wdt_miscdev.minor, rc); | |
c6cb13ae | 391 | goto err_out_reboot; |
1da177e4 LT |
392 | } |
393 | ||
c1cfd1a2 AC |
394 | printk(KERN_INFO PFX |
395 | "WDT driver for W83877F initialised. timeout=%d sec (nowayout=%d)\n", | |
1da177e4 LT |
396 | timeout, nowayout); |
397 | ||
398 | return 0; | |
399 | ||
c6cb13ae WVS |
400 | err_out_reboot: |
401 | unregister_reboot_notifier(&wdt_notifier); | |
1da177e4 | 402 | err_out_region2: |
c1cfd1a2 | 403 | release_region(WDT_PING, 1); |
1da177e4 | 404 | err_out_region1: |
c1cfd1a2 | 405 | release_region(ENABLE_W83877F_PORT, 2); |
1da177e4 LT |
406 | err_out: |
407 | return rc; | |
408 | } | |
409 | ||
410 | module_init(w83877f_wdt_init); | |
411 | module_exit(w83877f_wdt_unload); | |
412 | ||
413 | MODULE_AUTHOR("Scott and Bill Jennings"); | |
414 | MODULE_DESCRIPTION("Driver for watchdog timer in w83877f chip"); | |
415 | MODULE_LICENSE("GPL"); | |
416 | MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR); |