diff options
author | Linus Torvalds <torvalds@ppc970.osdl.org> | 2005-04-16 18:20:36 -0400 |
---|---|---|
committer | Linus Torvalds <torvalds@ppc970.osdl.org> | 2005-04-16 18:20:36 -0400 |
commit | 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 (patch) | |
tree | 0bba044c4ce775e45a88a51686b5d9f90697ea9d /drivers/char/watchdog/w83877f_wdt.c |
Linux-2.6.12-rc2v2.6.12-rc2
Initial git repository build. I'm not bothering with the full history,
even though we have it. We can create a separate "historical" git
archive of that later if we want to, and in the meantime it's about
3.2GB when imported into git - space that would just make the early
git days unnecessarily complicated, when we don't have a lot of good
infrastructure for it.
Let it rip!
Diffstat (limited to 'drivers/char/watchdog/w83877f_wdt.c')
-rw-r--r-- | drivers/char/watchdog/w83877f_wdt.c | 426 |
1 files changed, 426 insertions, 0 deletions
diff --git a/drivers/char/watchdog/w83877f_wdt.c b/drivers/char/watchdog/w83877f_wdt.c new file mode 100644 index 000000000000..bccbd4d6ac2d --- /dev/null +++ b/drivers/char/watchdog/w83877f_wdt.c | |||
@@ -0,0 +1,426 @@ | |||
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 | ||
26 | * changed watchdog_info to correctly reflect what the driver offers | ||
27 | * added WDIOC_GETSTATUS, WDIOC_GETBOOTSTATUS, WDIOC_SETTIMEOUT, | ||
28 | * WDIOC_GETTIMEOUT, and WDIOC_SETOPTIONS ioctls | ||
29 | * 09/8 - 2003 [wim@iguana.be] cleanup of trailing spaces | ||
30 | * added extra printk's for startup problems | ||
31 | * use module_param | ||
32 | * made timeout (the emulated heartbeat) a module_param | ||
33 | * made the keepalive ping an internal subroutine | ||
34 | * | ||
35 | * This WDT driver is different from most other Linux WDT | ||
36 | * drivers in that the driver will ping the watchdog by itself, | ||
37 | * because this particular WDT has a very short timeout (1.6 | ||
38 | * seconds) and it would be insane to count on any userspace | ||
39 | * daemon always getting scheduled within that time frame. | ||
40 | */ | ||
41 | |||
42 | #include <linux/module.h> | ||
43 | #include <linux/moduleparam.h> | ||
44 | #include <linux/types.h> | ||
45 | #include <linux/timer.h> | ||
46 | #include <linux/jiffies.h> | ||
47 | #include <linux/miscdevice.h> | ||
48 | #include <linux/watchdog.h> | ||
49 | #include <linux/fs.h> | ||
50 | #include <linux/ioport.h> | ||
51 | #include <linux/notifier.h> | ||
52 | #include <linux/reboot.h> | ||
53 | #include <linux/init.h> | ||
54 | #include <asm/io.h> | ||
55 | #include <asm/uaccess.h> | ||
56 | #include <asm/system.h> | ||
57 | |||
58 | #define OUR_NAME "w83877f_wdt" | ||
59 | #define PFX OUR_NAME ": " | ||
60 | |||
61 | #define ENABLE_W83877F_PORT 0x3F0 | ||
62 | #define ENABLE_W83877F 0x87 | ||
63 | #define DISABLE_W83877F 0xAA | ||
64 | #define WDT_PING 0x443 | ||
65 | #define WDT_REGISTER 0x14 | ||
66 | #define WDT_ENABLE 0x9C | ||
67 | #define WDT_DISABLE 0x8C | ||
68 | |||
69 | /* | ||
70 | * The W83877F seems to be fixed at 1.6s timeout (at least on the | ||
71 | * EMACS PC-104 board I'm using). If we reset the watchdog every | ||
72 | * ~250ms we should be safe. */ | ||
73 | |||
74 | #define WDT_INTERVAL (HZ/4+1) | ||
75 | |||
76 | /* | ||
77 | * We must not require too good response from the userspace daemon. | ||
78 | * Here we require the userspace daemon to send us a heartbeat | ||
79 | * char to /dev/watchdog every 30 seconds. | ||
80 | */ | ||
81 | |||
82 | #define WATCHDOG_TIMEOUT 30 /* 30 sec default timeout */ | ||
83 | static int timeout = WATCHDOG_TIMEOUT; /* in seconds, will be multiplied by HZ to get seconds to wait for a ping */ | ||
84 | module_param(timeout, int, 0); | ||
85 | MODULE_PARM_DESC(timeout, "Watchdog timeout in seconds. (1<=timeout<=3600, default=" __MODULE_STRING(WATCHDOG_TIMEOUT) ")"); | ||
86 | |||
87 | |||
88 | #ifdef CONFIG_WATCHDOG_NOWAYOUT | ||
89 | static int nowayout = 1; | ||
90 | #else | ||
91 | static int nowayout = 0; | ||
92 | #endif | ||
93 | |||
94 | module_param(nowayout, int, 0); | ||
95 | MODULE_PARM_DESC(nowayout, "Watchdog cannot be stopped once started (default=CONFIG_WATCHDOG_NOWAYOUT)"); | ||
96 | |||
97 | static void wdt_timer_ping(unsigned long); | ||
98 | static struct timer_list timer; | ||
99 | static unsigned long next_heartbeat; | ||
100 | static unsigned long wdt_is_open; | ||
101 | static char wdt_expect_close; | ||
102 | static spinlock_t wdt_spinlock; | ||
103 | |||
104 | /* | ||
105 | * Whack the dog | ||
106 | */ | ||
107 | |||
108 | static void wdt_timer_ping(unsigned long data) | ||
109 | { | ||
110 | /* If we got a heartbeat pulse within the WDT_US_INTERVAL | ||
111 | * we agree to ping the WDT | ||
112 | */ | ||
113 | if(time_before(jiffies, next_heartbeat)) | ||
114 | { | ||
115 | /* Ping the WDT */ | ||
116 | spin_lock(&wdt_spinlock); | ||
117 | |||
118 | /* Ping the WDT by reading from WDT_PING */ | ||
119 | inb_p(WDT_PING); | ||
120 | |||
121 | /* Re-set the timer interval */ | ||
122 | timer.expires = jiffies + WDT_INTERVAL; | ||
123 | add_timer(&timer); | ||
124 | |||
125 | spin_unlock(&wdt_spinlock); | ||
126 | |||
127 | } else { | ||
128 | printk(KERN_WARNING PFX "Heartbeat lost! Will not ping the watchdog\n"); | ||
129 | } | ||
130 | } | ||
131 | |||
132 | /* | ||
133 | * Utility routines | ||
134 | */ | ||
135 | |||
136 | static void wdt_change(int writeval) | ||
137 | { | ||
138 | unsigned long flags; | ||
139 | spin_lock_irqsave(&wdt_spinlock, flags); | ||
140 | |||
141 | /* buy some time */ | ||
142 | inb_p(WDT_PING); | ||
143 | |||
144 | /* make W83877F available */ | ||
145 | outb_p(ENABLE_W83877F, ENABLE_W83877F_PORT); | ||
146 | outb_p(ENABLE_W83877F, ENABLE_W83877F_PORT); | ||
147 | |||
148 | /* enable watchdog */ | ||
149 | outb_p(WDT_REGISTER, ENABLE_W83877F_PORT); | ||
150 | outb_p(writeval, ENABLE_W83877F_PORT+1); | ||
151 | |||
152 | /* lock the W8387FF away */ | ||
153 | outb_p(DISABLE_W83877F, ENABLE_W83877F_PORT); | ||
154 | |||
155 | spin_unlock_irqrestore(&wdt_spinlock, flags); | ||
156 | } | ||
157 | |||
158 | static void wdt_startup(void) | ||
159 | { | ||
160 | next_heartbeat = jiffies + (timeout * HZ); | ||
161 | |||
162 | /* Start the timer */ | ||
163 | timer.expires = jiffies + WDT_INTERVAL; | ||
164 | add_timer(&timer); | ||
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 | |||
191 | static ssize_t fop_write(struct file * file, const char __user * buf, size_t count, loff_t * ppos) | ||
192 | { | ||
193 | /* See if we got the magic character 'V' and reload the timer */ | ||
194 | if(count) | ||
195 | { | ||
196 | if (!nowayout) | ||
197 | { | ||
198 | size_t ofs; | ||
199 | |||
200 | /* note: just in case someone wrote the magic character | ||
201 | * five months ago... */ | ||
202 | wdt_expect_close = 0; | ||
203 | |||
204 | /* scan to see whether or not we got the magic character */ | ||
205 | for(ofs = 0; ofs != count; ofs++) | ||
206 | { | ||
207 | char c; | ||
208 | if (get_user(c, buf + ofs)) | ||
209 | return -EFAULT; | ||
210 | if (c == 'V') | ||
211 | wdt_expect_close = 42; | ||
212 | } | ||
213 | } | ||
214 | |||
215 | /* someone wrote to us, we should restart timer */ | ||
216 | wdt_keepalive(); | ||
217 | } | ||
218 | return count; | ||
219 | } | ||
220 | |||
221 | static int fop_open(struct inode * inode, struct file * file) | ||
222 | { | ||
223 | /* Just in case we're already talking to someone... */ | ||
224 | if(test_and_set_bit(0, &wdt_is_open)) | ||
225 | return -EBUSY; | ||
226 | |||
227 | /* Good, fire up the show */ | ||
228 | wdt_startup(); | ||
229 | return nonseekable_open(inode, file); | ||
230 | } | ||
231 | |||
232 | static int fop_close(struct inode * inode, struct file * file) | ||
233 | { | ||
234 | if(wdt_expect_close == 42) | ||
235 | wdt_turnoff(); | ||
236 | else { | ||
237 | del_timer(&timer); | ||
238 | printk(KERN_CRIT PFX "device file closed unexpectedly. Will not stop the WDT!\n"); | ||
239 | } | ||
240 | clear_bit(0, &wdt_is_open); | ||
241 | wdt_expect_close = 0; | ||
242 | return 0; | ||
243 | } | ||
244 | |||
245 | static int fop_ioctl(struct inode *inode, struct file *file, unsigned int cmd, | ||
246 | unsigned long arg) | ||
247 | { | ||
248 | void __user *argp = (void __user *)arg; | ||
249 | int __user *p = argp; | ||
250 | static struct watchdog_info ident= | ||
251 | { | ||
252 | .options = WDIOF_KEEPALIVEPING | WDIOF_SETTIMEOUT | WDIOF_MAGICCLOSE, | ||
253 | .firmware_version = 1, | ||
254 | .identity = "W83877F", | ||
255 | }; | ||
256 | |||
257 | switch(cmd) | ||
258 | { | ||
259 | default: | ||
260 | return -ENOIOCTLCMD; | ||
261 | case WDIOC_GETSUPPORT: | ||
262 | return copy_to_user(argp, &ident, sizeof(ident))?-EFAULT:0; | ||
263 | case WDIOC_GETSTATUS: | ||
264 | case WDIOC_GETBOOTSTATUS: | ||
265 | return put_user(0, p); | ||
266 | case WDIOC_KEEPALIVE: | ||
267 | wdt_keepalive(); | ||
268 | return 0; | ||
269 | case WDIOC_SETOPTIONS: | ||
270 | { | ||
271 | int new_options, retval = -EINVAL; | ||
272 | |||
273 | if(get_user(new_options, p)) | ||
274 | return -EFAULT; | ||
275 | |||
276 | if(new_options & WDIOS_DISABLECARD) { | ||
277 | wdt_turnoff(); | ||
278 | retval = 0; | ||
279 | } | ||
280 | |||
281 | if(new_options & WDIOS_ENABLECARD) { | ||
282 | wdt_startup(); | ||
283 | retval = 0; | ||
284 | } | ||
285 | |||
286 | return retval; | ||
287 | } | ||
288 | case WDIOC_SETTIMEOUT: | ||
289 | { | ||
290 | int new_timeout; | ||
291 | |||
292 | if(get_user(new_timeout, p)) | ||
293 | return -EFAULT; | ||
294 | |||
295 | if(new_timeout < 1 || new_timeout > 3600) /* arbitrary upper limit */ | ||
296 | return -EINVAL; | ||
297 | |||
298 | timeout = new_timeout; | ||
299 | wdt_keepalive(); | ||
300 | /* Fall through */ | ||
301 | } | ||
302 | case WDIOC_GETTIMEOUT: | ||
303 | return put_user(timeout, p); | ||
304 | } | ||
305 | } | ||
306 | |||
307 | static struct file_operations wdt_fops = { | ||
308 | .owner = THIS_MODULE, | ||
309 | .llseek = no_llseek, | ||
310 | .write = fop_write, | ||
311 | .open = fop_open, | ||
312 | .release = fop_close, | ||
313 | .ioctl = fop_ioctl, | ||
314 | }; | ||
315 | |||
316 | static struct miscdevice wdt_miscdev = { | ||
317 | .minor = WATCHDOG_MINOR, | ||
318 | .name = "watchdog", | ||
319 | .fops = &wdt_fops, | ||
320 | }; | ||
321 | |||
322 | /* | ||
323 | * Notifier for system down | ||
324 | */ | ||
325 | |||
326 | static int wdt_notify_sys(struct notifier_block *this, unsigned long code, | ||
327 | void *unused) | ||
328 | { | ||
329 | if(code==SYS_DOWN || code==SYS_HALT) | ||
330 | wdt_turnoff(); | ||
331 | return NOTIFY_DONE; | ||
332 | } | ||
333 | |||
334 | /* | ||
335 | * The WDT needs to learn about soft shutdowns in order to | ||
336 | * turn the timebomb registers off. | ||
337 | */ | ||
338 | |||
339 | static struct notifier_block wdt_notifier= | ||
340 | { | ||
341 | .notifier_call = wdt_notify_sys, | ||
342 | }; | ||
343 | |||
344 | static void __exit w83877f_wdt_unload(void) | ||
345 | { | ||
346 | wdt_turnoff(); | ||
347 | |||
348 | /* Deregister */ | ||
349 | misc_deregister(&wdt_miscdev); | ||
350 | |||
351 | unregister_reboot_notifier(&wdt_notifier); | ||
352 | release_region(WDT_PING,1); | ||
353 | release_region(ENABLE_W83877F_PORT,2); | ||
354 | } | ||
355 | |||
356 | static int __init w83877f_wdt_init(void) | ||
357 | { | ||
358 | int rc = -EBUSY; | ||
359 | |||
360 | spin_lock_init(&wdt_spinlock); | ||
361 | |||
362 | if(timeout < 1 || timeout > 3600) /* arbitrary upper limit */ | ||
363 | { | ||
364 | timeout = WATCHDOG_TIMEOUT; | ||
365 | printk(KERN_INFO PFX "timeout value must be 1<=x<=3600, using %d\n", | ||
366 | timeout); | ||
367 | } | ||
368 | |||
369 | if (!request_region(ENABLE_W83877F_PORT, 2, "W83877F WDT")) | ||
370 | { | ||
371 | printk(KERN_ERR PFX "I/O address 0x%04x already in use\n", | ||
372 | ENABLE_W83877F_PORT); | ||
373 | rc = -EIO; | ||
374 | goto err_out; | ||
375 | } | ||
376 | |||
377 | if (!request_region(WDT_PING, 1, "W8387FF WDT")) | ||
378 | { | ||
379 | printk(KERN_ERR PFX "I/O address 0x%04x already in use\n", | ||
380 | WDT_PING); | ||
381 | rc = -EIO; | ||
382 | goto err_out_region1; | ||
383 | } | ||
384 | |||
385 | init_timer(&timer); | ||
386 | timer.function = wdt_timer_ping; | ||
387 | timer.data = 0; | ||
388 | |||
389 | rc = misc_register(&wdt_miscdev); | ||
390 | if (rc) | ||
391 | { | ||
392 | printk(KERN_ERR PFX "cannot register miscdev on minor=%d (err=%d)\n", | ||
393 | wdt_miscdev.minor, rc); | ||
394 | goto err_out_region2; | ||
395 | } | ||
396 | |||
397 | rc = register_reboot_notifier(&wdt_notifier); | ||
398 | if (rc) | ||
399 | { | ||
400 | printk(KERN_ERR PFX "cannot register reboot notifier (err=%d)\n", | ||
401 | rc); | ||
402 | goto err_out_miscdev; | ||
403 | } | ||
404 | |||
405 | printk(KERN_INFO PFX "WDT driver for W83877F initialised. timeout=%d sec (nowayout=%d)\n", | ||
406 | timeout, nowayout); | ||
407 | |||
408 | return 0; | ||
409 | |||
410 | err_out_miscdev: | ||
411 | misc_deregister(&wdt_miscdev); | ||
412 | err_out_region2: | ||
413 | release_region(WDT_PING,1); | ||
414 | err_out_region1: | ||
415 | release_region(ENABLE_W83877F_PORT,2); | ||
416 | err_out: | ||
417 | return rc; | ||
418 | } | ||
419 | |||
420 | module_init(w83877f_wdt_init); | ||
421 | module_exit(w83877f_wdt_unload); | ||
422 | |||
423 | MODULE_AUTHOR("Scott and Bill Jennings"); | ||
424 | MODULE_DESCRIPTION("Driver for watchdog timer in w83877f chip"); | ||
425 | MODULE_LICENSE("GPL"); | ||
426 | MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR); | ||