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1da177e4 LT |
1 | /* |
2 | * Wdt977 0.03: A Watchdog Device for Netwinder W83977AF chip | |
3 | * | |
4 | * (c) Copyright 1998 Rebel.com (Woody Suwalski <woody@netwinder.org>) | |
5 | * | |
6 | * ----------------------- | |
7 | * | |
8 | * This program is free software; you can redistribute it and/or | |
9 | * modify it under the terms of the GNU General Public License | |
10 | * as published by the Free Software Foundation; either version | |
11 | * 2 of the License, or (at your option) any later version. | |
12 | * | |
13 | * ----------------------- | |
14 | * 14-Dec-2001 Matt Domsch <Matt_Domsch@dell.com> | |
15 | * Added nowayout module option to override CONFIG_WATCHDOG_NOWAYOUT | |
16 | * 19-Dec-2001 Woody Suwalski: Netwinder fixes, ioctl interface | |
17 | * 06-Jan-2002 Woody Suwalski: For compatibility, convert all timeouts | |
18 | * from minutes to seconds. | |
19 | * 07-Jul-2003 Daniele Bellucci: Audit return code of misc_register in | |
20 | * nwwatchdog_init. | |
21 | */ | |
22 | ||
23 | #include <linux/module.h> | |
24 | #include <linux/moduleparam.h> | |
25 | #include <linux/config.h> | |
26 | #include <linux/types.h> | |
27 | #include <linux/kernel.h> | |
28 | #include <linux/fs.h> | |
29 | #include <linux/miscdevice.h> | |
30 | #include <linux/init.h> | |
31 | #include <linux/watchdog.h> | |
32 | #include <linux/notifier.h> | |
33 | #include <linux/reboot.h> | |
34 | ||
35 | #include <asm/io.h> | |
36 | #include <asm/system.h> | |
37 | #include <asm/mach-types.h> | |
38 | #include <asm/uaccess.h> | |
39 | ||
40 | #define PFX "Wdt977: " | |
41 | #define WATCHDOG_MINOR 130 | |
42 | ||
43 | #define DEFAULT_TIMEOUT 60 /* default timeout in seconds */ | |
44 | ||
45 | static int timeout = DEFAULT_TIMEOUT; | |
46 | static int timeoutM; /* timeout in minutes */ | |
47 | static unsigned long timer_alive; | |
48 | static int testmode; | |
49 | static char expect_close; | |
50 | ||
51 | module_param(timeout, int, 0); | |
52 | MODULE_PARM_DESC(timeout,"Watchdog timeout in seconds (60..15300), default=" __MODULE_STRING(DEFAULT_TIMEOUT) ")"); | |
53 | module_param(testmode, int, 0); | |
54 | MODULE_PARM_DESC(testmode,"Watchdog testmode (1 = no reboot), default=0"); | |
55 | ||
4bfdf378 | 56 | static int nowayout = WATCHDOG_NOWAYOUT; |
1da177e4 LT |
57 | module_param(nowayout, int, 0); |
58 | MODULE_PARM_DESC(nowayout, "Watchdog cannot be stopped once started (default=CONFIG_WATCHDOG_NOWAYOUT)"); | |
59 | ||
60 | /* | |
61 | * Start the watchdog | |
62 | */ | |
63 | ||
64 | static int wdt977_start(void) | |
65 | { | |
66 | /* unlock the SuperIO chip */ | |
67 | outb(0x87,0x370); | |
68 | outb(0x87,0x370); | |
69 | ||
70 | /* select device Aux2 (device=8) and set watchdog regs F2, F3 and F4 | |
71 | * F2 has the timeout in minutes | |
72 | * F3 could be set to the POWER LED blink (with GP17 set to PowerLed) | |
73 | * at timeout, and to reset timer on kbd/mouse activity (not impl.) | |
74 | * F4 is used to just clear the TIMEOUT'ed state (bit 0) | |
75 | */ | |
76 | outb(0x07,0x370); | |
77 | outb(0x08,0x371); | |
78 | outb(0xF2,0x370); | |
79 | outb(timeoutM,0x371); | |
80 | outb(0xF3,0x370); | |
81 | outb(0x00,0x371); /* another setting is 0E for kbd/mouse/LED */ | |
82 | outb(0xF4,0x370); | |
83 | outb(0x00,0x371); | |
84 | ||
85 | /* at last select device Aux1 (dev=7) and set GP16 as a watchdog output */ | |
86 | /* in test mode watch the bit 1 on F4 to indicate "triggered" */ | |
87 | if (!testmode) | |
88 | { | |
89 | outb(0x07,0x370); | |
90 | outb(0x07,0x371); | |
91 | outb(0xE6,0x370); | |
92 | outb(0x08,0x371); | |
93 | } | |
94 | ||
95 | /* lock the SuperIO chip */ | |
96 | outb(0xAA,0x370); | |
97 | ||
98 | printk(KERN_INFO PFX "activated.\n"); | |
99 | ||
100 | return 0; | |
101 | } | |
102 | ||
103 | /* | |
104 | * Stop the watchdog | |
105 | */ | |
106 | ||
107 | static int wdt977_stop(void) | |
108 | { | |
109 | /* unlock the SuperIO chip */ | |
110 | outb(0x87,0x370); | |
111 | outb(0x87,0x370); | |
112 | ||
113 | /* select device Aux2 (device=8) and set watchdog regs F2,F3 and F4 | |
114 | * F3 is reset to its default state | |
115 | * F4 can clear the TIMEOUT'ed state (bit 0) - back to default | |
116 | * We can not use GP17 as a PowerLed, as we use its usage as a RedLed | |
117 | */ | |
118 | outb(0x07,0x370); | |
119 | outb(0x08,0x371); | |
120 | outb(0xF2,0x370); | |
121 | outb(0xFF,0x371); | |
122 | outb(0xF3,0x370); | |
123 | outb(0x00,0x371); | |
124 | outb(0xF4,0x370); | |
125 | outb(0x00,0x371); | |
126 | outb(0xF2,0x370); | |
127 | outb(0x00,0x371); | |
128 | ||
129 | /* at last select device Aux1 (dev=7) and set GP16 as a watchdog output */ | |
130 | outb(0x07,0x370); | |
131 | outb(0x07,0x371); | |
132 | outb(0xE6,0x370); | |
133 | outb(0x08,0x371); | |
134 | ||
135 | /* lock the SuperIO chip */ | |
136 | outb(0xAA,0x370); | |
137 | ||
138 | printk(KERN_INFO PFX "shutdown.\n"); | |
139 | ||
140 | return 0; | |
141 | } | |
142 | ||
143 | /* | |
144 | * Send a keepalive ping to the watchdog | |
145 | * This is done by simply re-writing the timeout to reg. 0xF2 | |
146 | */ | |
147 | ||
148 | static int wdt977_keepalive(void) | |
149 | { | |
150 | /* unlock the SuperIO chip */ | |
151 | outb(0x87,0x370); | |
152 | outb(0x87,0x370); | |
153 | ||
154 | /* select device Aux2 (device=8) and kicks watchdog reg F2 */ | |
155 | /* F2 has the timeout in minutes */ | |
156 | outb(0x07,0x370); | |
157 | outb(0x08,0x371); | |
158 | outb(0xF2,0x370); | |
159 | outb(timeoutM,0x371); | |
160 | ||
161 | /* lock the SuperIO chip */ | |
162 | outb(0xAA,0x370); | |
163 | ||
164 | return 0; | |
165 | } | |
166 | ||
167 | /* | |
168 | * Set the watchdog timeout value | |
169 | */ | |
170 | ||
171 | static int wdt977_set_timeout(int t) | |
172 | { | |
173 | int tmrval; | |
174 | ||
175 | /* convert seconds to minutes, rounding up */ | |
176 | tmrval = (t + 59) / 60; | |
177 | ||
178 | if (machine_is_netwinder()) { | |
179 | /* we have a hw bug somewhere, so each 977 minute is actually only 30sec | |
180 | * this limits the max timeout to half of device max of 255 minutes... | |
181 | */ | |
182 | tmrval += tmrval; | |
183 | } | |
184 | ||
185 | if ((tmrval < 1) || (tmrval > 255)) | |
186 | return -EINVAL; | |
187 | ||
188 | /* timeout is the timeout in seconds, timeoutM is the timeout in minutes) */ | |
189 | timeout = t; | |
190 | timeoutM = tmrval; | |
191 | return 0; | |
192 | } | |
193 | ||
194 | /* | |
195 | * Get the watchdog status | |
196 | */ | |
197 | ||
198 | static int wdt977_get_status(int *status) | |
199 | { | |
200 | int new_status; | |
201 | ||
202 | *status=0; | |
203 | ||
204 | /* unlock the SuperIO chip */ | |
205 | outb(0x87,0x370); | |
206 | outb(0x87,0x370); | |
207 | ||
208 | /* select device Aux2 (device=8) and read watchdog reg F4 */ | |
209 | outb(0x07,0x370); | |
210 | outb(0x08,0x371); | |
211 | outb(0xF4,0x370); | |
212 | new_status = inb(0x371); | |
213 | ||
214 | /* lock the SuperIO chip */ | |
215 | outb(0xAA,0x370); | |
216 | ||
217 | if (new_status & 1) | |
218 | *status |= WDIOF_CARDRESET; | |
219 | ||
220 | return 0; | |
221 | } | |
222 | ||
223 | ||
224 | /* | |
225 | * /dev/watchdog handling | |
226 | */ | |
227 | ||
228 | static int wdt977_open(struct inode *inode, struct file *file) | |
229 | { | |
230 | /* If the watchdog is alive we don't need to start it again */ | |
231 | if( test_and_set_bit(0,&timer_alive) ) | |
232 | return -EBUSY; | |
233 | ||
234 | if (nowayout) | |
235 | __module_get(THIS_MODULE); | |
236 | ||
237 | wdt977_start(); | |
238 | return nonseekable_open(inode, file); | |
239 | } | |
240 | ||
241 | static int wdt977_release(struct inode *inode, struct file *file) | |
242 | { | |
243 | /* | |
244 | * Shut off the timer. | |
245 | * Lock it in if it's a module and we set nowayout | |
246 | */ | |
247 | if (expect_close == 42) | |
248 | { | |
249 | wdt977_stop(); | |
250 | clear_bit(0,&timer_alive); | |
251 | } else { | |
252 | printk(KERN_CRIT PFX "Unexpected close, not stopping watchdog!\n"); | |
253 | wdt977_keepalive(); | |
254 | } | |
255 | expect_close = 0; | |
256 | return 0; | |
257 | } | |
258 | ||
259 | ||
260 | /* | |
261 | * wdt977_write: | |
262 | * @file: file handle to the watchdog | |
263 | * @buf: buffer to write (unused as data does not matter here | |
264 | * @count: count of bytes | |
265 | * @ppos: pointer to the position to write. No seeks allowed | |
266 | * | |
267 | * A write to a watchdog device is defined as a keepalive signal. Any | |
268 | * write of data will do, as we we don't define content meaning. | |
269 | */ | |
270 | ||
271 | static ssize_t wdt977_write(struct file *file, const char __user *buf, | |
272 | size_t count, loff_t *ppos) | |
273 | { | |
274 | if (count) { | |
275 | if (!nowayout) { | |
276 | size_t i; | |
277 | ||
278 | /* In case it was set long ago */ | |
279 | expect_close = 0; | |
280 | ||
281 | for (i = 0; i != count; i++) { | |
282 | char c; | |
283 | if (get_user(c, buf + i)) | |
284 | return -EFAULT; | |
285 | if (c == 'V') | |
286 | expect_close = 42; | |
287 | } | |
288 | } | |
289 | ||
290 | wdt977_keepalive(); | |
291 | } | |
292 | return count; | |
293 | } | |
294 | ||
295 | /* | |
296 | * wdt977_ioctl: | |
297 | * @inode: inode of the device | |
298 | * @file: file handle to the device | |
299 | * @cmd: watchdog command | |
300 | * @arg: argument pointer | |
301 | * | |
302 | * The watchdog API defines a common set of functions for all watchdogs | |
303 | * according to their available features. | |
304 | */ | |
305 | ||
306 | static struct watchdog_info ident = { | |
307 | .options = WDIOF_SETTIMEOUT | | |
308 | WDIOF_MAGICCLOSE | | |
309 | WDIOF_KEEPALIVEPING, | |
310 | .firmware_version = 1, | |
311 | .identity = "Winbond 83977", | |
312 | }; | |
313 | ||
314 | static int wdt977_ioctl(struct inode *inode, struct file *file, | |
315 | unsigned int cmd, unsigned long arg) | |
316 | { | |
317 | int status; | |
318 | int new_options, retval = -EINVAL; | |
319 | int new_timeout; | |
320 | union { | |
321 | struct watchdog_info __user *ident; | |
322 | int __user *i; | |
323 | } uarg; | |
324 | ||
325 | uarg.i = (int __user *)arg; | |
326 | ||
327 | switch(cmd) | |
328 | { | |
329 | default: | |
330 | return -ENOIOCTLCMD; | |
331 | ||
332 | case WDIOC_GETSUPPORT: | |
333 | return copy_to_user(uarg.ident, &ident, | |
334 | sizeof(ident)) ? -EFAULT : 0; | |
335 | ||
336 | case WDIOC_GETSTATUS: | |
337 | wdt977_get_status(&status); | |
338 | return put_user(status, uarg.i); | |
339 | ||
340 | case WDIOC_GETBOOTSTATUS: | |
341 | return put_user(0, uarg.i); | |
342 | ||
343 | case WDIOC_KEEPALIVE: | |
344 | wdt977_keepalive(); | |
345 | return 0; | |
346 | ||
347 | case WDIOC_SETOPTIONS: | |
348 | if (get_user (new_options, uarg.i)) | |
349 | return -EFAULT; | |
350 | ||
351 | if (new_options & WDIOS_DISABLECARD) { | |
352 | wdt977_stop(); | |
353 | retval = 0; | |
354 | } | |
355 | ||
356 | if (new_options & WDIOS_ENABLECARD) { | |
357 | wdt977_start(); | |
358 | retval = 0; | |
359 | } | |
360 | ||
361 | return retval; | |
362 | ||
363 | case WDIOC_SETTIMEOUT: | |
364 | if (get_user(new_timeout, uarg.i)) | |
365 | return -EFAULT; | |
366 | ||
367 | if (wdt977_set_timeout(new_timeout)) | |
368 | return -EINVAL; | |
369 | ||
370 | wdt977_keepalive(); | |
371 | /* Fall */ | |
372 | ||
373 | case WDIOC_GETTIMEOUT: | |
374 | return put_user(timeout, uarg.i); | |
375 | ||
376 | } | |
377 | } | |
378 | ||
379 | static int wdt977_notify_sys(struct notifier_block *this, unsigned long code, | |
380 | void *unused) | |
381 | { | |
382 | if(code==SYS_DOWN || code==SYS_HALT) | |
383 | wdt977_stop(); | |
384 | return NOTIFY_DONE; | |
385 | } | |
386 | ||
387 | static struct file_operations wdt977_fops= | |
388 | { | |
389 | .owner = THIS_MODULE, | |
390 | .llseek = no_llseek, | |
391 | .write = wdt977_write, | |
392 | .ioctl = wdt977_ioctl, | |
393 | .open = wdt977_open, | |
394 | .release = wdt977_release, | |
395 | }; | |
396 | ||
397 | static struct miscdevice wdt977_miscdev= | |
398 | { | |
399 | .minor = WATCHDOG_MINOR, | |
400 | .name = "watchdog", | |
401 | .fops = &wdt977_fops, | |
402 | }; | |
403 | ||
404 | static struct notifier_block wdt977_notifier = { | |
405 | .notifier_call = wdt977_notify_sys, | |
406 | }; | |
407 | ||
408 | static int __init nwwatchdog_init(void) | |
409 | { | |
410 | int retval; | |
411 | if (!machine_is_netwinder()) | |
412 | return -ENODEV; | |
413 | ||
414 | /* Check that the timeout value is within it's range ; if not reset to the default */ | |
415 | if (wdt977_set_timeout(timeout)) { | |
416 | wdt977_set_timeout(DEFAULT_TIMEOUT); | |
417 | printk(KERN_INFO PFX "timeout value must be 60<timeout<15300, using %d\n", | |
418 | DEFAULT_TIMEOUT); | |
419 | } | |
420 | ||
421 | retval = register_reboot_notifier(&wdt977_notifier); | |
422 | if (retval) { | |
423 | printk(KERN_ERR PFX "cannot register reboot notifier (err=%d)\n", | |
424 | retval); | |
425 | return retval; | |
426 | } | |
427 | ||
428 | retval = misc_register(&wdt977_miscdev); | |
429 | if (retval) { | |
430 | printk(KERN_ERR PFX "cannot register miscdev on minor=%d (err=%d)\n", | |
431 | WATCHDOG_MINOR, retval); | |
432 | unregister_reboot_notifier(&wdt977_notifier); | |
433 | return retval; | |
434 | } | |
435 | ||
436 | printk(KERN_INFO PFX "initialized. timeout=%d sec (nowayout=%d, testmode = %i)\n", | |
437 | timeout, nowayout, testmode); | |
438 | ||
439 | return 0; | |
440 | } | |
441 | ||
442 | static void __exit nwwatchdog_exit(void) | |
443 | { | |
444 | misc_deregister(&wdt977_miscdev); | |
445 | unregister_reboot_notifier(&wdt977_notifier); | |
446 | } | |
447 | ||
448 | module_init(nwwatchdog_init); | |
449 | module_exit(nwwatchdog_exit); | |
450 | ||
451 | MODULE_AUTHOR("Woody Suwalski <woody@netwinder.org>"); | |
452 | MODULE_DESCRIPTION("W83977AF Watchdog driver"); | |
453 | MODULE_LICENSE("GPL"); | |
454 | MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR); |