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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 | ||
56 | #ifdef CONFIG_WATCHDOG_NOWAYOUT | |
57 | static int nowayout = 1; | |
58 | #else | |
59 | static int nowayout = 0; | |
60 | #endif | |
61 | ||
62 | module_param(nowayout, int, 0); | |
63 | MODULE_PARM_DESC(nowayout, "Watchdog cannot be stopped once started (default=CONFIG_WATCHDOG_NOWAYOUT)"); | |
64 | ||
65 | /* | |
66 | * Start the watchdog | |
67 | */ | |
68 | ||
69 | static int wdt977_start(void) | |
70 | { | |
71 | /* unlock the SuperIO chip */ | |
72 | outb(0x87,0x370); | |
73 | outb(0x87,0x370); | |
74 | ||
75 | /* select device Aux2 (device=8) and set watchdog regs F2, F3 and F4 | |
76 | * F2 has the timeout in minutes | |
77 | * F3 could be set to the POWER LED blink (with GP17 set to PowerLed) | |
78 | * at timeout, and to reset timer on kbd/mouse activity (not impl.) | |
79 | * F4 is used to just clear the TIMEOUT'ed state (bit 0) | |
80 | */ | |
81 | outb(0x07,0x370); | |
82 | outb(0x08,0x371); | |
83 | outb(0xF2,0x370); | |
84 | outb(timeoutM,0x371); | |
85 | outb(0xF3,0x370); | |
86 | outb(0x00,0x371); /* another setting is 0E for kbd/mouse/LED */ | |
87 | outb(0xF4,0x370); | |
88 | outb(0x00,0x371); | |
89 | ||
90 | /* at last select device Aux1 (dev=7) and set GP16 as a watchdog output */ | |
91 | /* in test mode watch the bit 1 on F4 to indicate "triggered" */ | |
92 | if (!testmode) | |
93 | { | |
94 | outb(0x07,0x370); | |
95 | outb(0x07,0x371); | |
96 | outb(0xE6,0x370); | |
97 | outb(0x08,0x371); | |
98 | } | |
99 | ||
100 | /* lock the SuperIO chip */ | |
101 | outb(0xAA,0x370); | |
102 | ||
103 | printk(KERN_INFO PFX "activated.\n"); | |
104 | ||
105 | return 0; | |
106 | } | |
107 | ||
108 | /* | |
109 | * Stop the watchdog | |
110 | */ | |
111 | ||
112 | static int wdt977_stop(void) | |
113 | { | |
114 | /* unlock the SuperIO chip */ | |
115 | outb(0x87,0x370); | |
116 | outb(0x87,0x370); | |
117 | ||
118 | /* select device Aux2 (device=8) and set watchdog regs F2,F3 and F4 | |
119 | * F3 is reset to its default state | |
120 | * F4 can clear the TIMEOUT'ed state (bit 0) - back to default | |
121 | * We can not use GP17 as a PowerLed, as we use its usage as a RedLed | |
122 | */ | |
123 | outb(0x07,0x370); | |
124 | outb(0x08,0x371); | |
125 | outb(0xF2,0x370); | |
126 | outb(0xFF,0x371); | |
127 | outb(0xF3,0x370); | |
128 | outb(0x00,0x371); | |
129 | outb(0xF4,0x370); | |
130 | outb(0x00,0x371); | |
131 | outb(0xF2,0x370); | |
132 | outb(0x00,0x371); | |
133 | ||
134 | /* at last select device Aux1 (dev=7) and set GP16 as a watchdog output */ | |
135 | outb(0x07,0x370); | |
136 | outb(0x07,0x371); | |
137 | outb(0xE6,0x370); | |
138 | outb(0x08,0x371); | |
139 | ||
140 | /* lock the SuperIO chip */ | |
141 | outb(0xAA,0x370); | |
142 | ||
143 | printk(KERN_INFO PFX "shutdown.\n"); | |
144 | ||
145 | return 0; | |
146 | } | |
147 | ||
148 | /* | |
149 | * Send a keepalive ping to the watchdog | |
150 | * This is done by simply re-writing the timeout to reg. 0xF2 | |
151 | */ | |
152 | ||
153 | static int wdt977_keepalive(void) | |
154 | { | |
155 | /* unlock the SuperIO chip */ | |
156 | outb(0x87,0x370); | |
157 | outb(0x87,0x370); | |
158 | ||
159 | /* select device Aux2 (device=8) and kicks watchdog reg F2 */ | |
160 | /* F2 has the timeout in minutes */ | |
161 | outb(0x07,0x370); | |
162 | outb(0x08,0x371); | |
163 | outb(0xF2,0x370); | |
164 | outb(timeoutM,0x371); | |
165 | ||
166 | /* lock the SuperIO chip */ | |
167 | outb(0xAA,0x370); | |
168 | ||
169 | return 0; | |
170 | } | |
171 | ||
172 | /* | |
173 | * Set the watchdog timeout value | |
174 | */ | |
175 | ||
176 | static int wdt977_set_timeout(int t) | |
177 | { | |
178 | int tmrval; | |
179 | ||
180 | /* convert seconds to minutes, rounding up */ | |
181 | tmrval = (t + 59) / 60; | |
182 | ||
183 | if (machine_is_netwinder()) { | |
184 | /* we have a hw bug somewhere, so each 977 minute is actually only 30sec | |
185 | * this limits the max timeout to half of device max of 255 minutes... | |
186 | */ | |
187 | tmrval += tmrval; | |
188 | } | |
189 | ||
190 | if ((tmrval < 1) || (tmrval > 255)) | |
191 | return -EINVAL; | |
192 | ||
193 | /* timeout is the timeout in seconds, timeoutM is the timeout in minutes) */ | |
194 | timeout = t; | |
195 | timeoutM = tmrval; | |
196 | return 0; | |
197 | } | |
198 | ||
199 | /* | |
200 | * Get the watchdog status | |
201 | */ | |
202 | ||
203 | static int wdt977_get_status(int *status) | |
204 | { | |
205 | int new_status; | |
206 | ||
207 | *status=0; | |
208 | ||
209 | /* unlock the SuperIO chip */ | |
210 | outb(0x87,0x370); | |
211 | outb(0x87,0x370); | |
212 | ||
213 | /* select device Aux2 (device=8) and read watchdog reg F4 */ | |
214 | outb(0x07,0x370); | |
215 | outb(0x08,0x371); | |
216 | outb(0xF4,0x370); | |
217 | new_status = inb(0x371); | |
218 | ||
219 | /* lock the SuperIO chip */ | |
220 | outb(0xAA,0x370); | |
221 | ||
222 | if (new_status & 1) | |
223 | *status |= WDIOF_CARDRESET; | |
224 | ||
225 | return 0; | |
226 | } | |
227 | ||
228 | ||
229 | /* | |
230 | * /dev/watchdog handling | |
231 | */ | |
232 | ||
233 | static int wdt977_open(struct inode *inode, struct file *file) | |
234 | { | |
235 | /* If the watchdog is alive we don't need to start it again */ | |
236 | if( test_and_set_bit(0,&timer_alive) ) | |
237 | return -EBUSY; | |
238 | ||
239 | if (nowayout) | |
240 | __module_get(THIS_MODULE); | |
241 | ||
242 | wdt977_start(); | |
243 | return nonseekable_open(inode, file); | |
244 | } | |
245 | ||
246 | static int wdt977_release(struct inode *inode, struct file *file) | |
247 | { | |
248 | /* | |
249 | * Shut off the timer. | |
250 | * Lock it in if it's a module and we set nowayout | |
251 | */ | |
252 | if (expect_close == 42) | |
253 | { | |
254 | wdt977_stop(); | |
255 | clear_bit(0,&timer_alive); | |
256 | } else { | |
257 | printk(KERN_CRIT PFX "Unexpected close, not stopping watchdog!\n"); | |
258 | wdt977_keepalive(); | |
259 | } | |
260 | expect_close = 0; | |
261 | return 0; | |
262 | } | |
263 | ||
264 | ||
265 | /* | |
266 | * wdt977_write: | |
267 | * @file: file handle to the watchdog | |
268 | * @buf: buffer to write (unused as data does not matter here | |
269 | * @count: count of bytes | |
270 | * @ppos: pointer to the position to write. No seeks allowed | |
271 | * | |
272 | * A write to a watchdog device is defined as a keepalive signal. Any | |
273 | * write of data will do, as we we don't define content meaning. | |
274 | */ | |
275 | ||
276 | static ssize_t wdt977_write(struct file *file, const char __user *buf, | |
277 | size_t count, loff_t *ppos) | |
278 | { | |
279 | if (count) { | |
280 | if (!nowayout) { | |
281 | size_t i; | |
282 | ||
283 | /* In case it was set long ago */ | |
284 | expect_close = 0; | |
285 | ||
286 | for (i = 0; i != count; i++) { | |
287 | char c; | |
288 | if (get_user(c, buf + i)) | |
289 | return -EFAULT; | |
290 | if (c == 'V') | |
291 | expect_close = 42; | |
292 | } | |
293 | } | |
294 | ||
295 | wdt977_keepalive(); | |
296 | } | |
297 | return count; | |
298 | } | |
299 | ||
300 | /* | |
301 | * wdt977_ioctl: | |
302 | * @inode: inode of the device | |
303 | * @file: file handle to the device | |
304 | * @cmd: watchdog command | |
305 | * @arg: argument pointer | |
306 | * | |
307 | * The watchdog API defines a common set of functions for all watchdogs | |
308 | * according to their available features. | |
309 | */ | |
310 | ||
311 | static struct watchdog_info ident = { | |
312 | .options = WDIOF_SETTIMEOUT | | |
313 | WDIOF_MAGICCLOSE | | |
314 | WDIOF_KEEPALIVEPING, | |
315 | .firmware_version = 1, | |
316 | .identity = "Winbond 83977", | |
317 | }; | |
318 | ||
319 | static int wdt977_ioctl(struct inode *inode, struct file *file, | |
320 | unsigned int cmd, unsigned long arg) | |
321 | { | |
322 | int status; | |
323 | int new_options, retval = -EINVAL; | |
324 | int new_timeout; | |
325 | union { | |
326 | struct watchdog_info __user *ident; | |
327 | int __user *i; | |
328 | } uarg; | |
329 | ||
330 | uarg.i = (int __user *)arg; | |
331 | ||
332 | switch(cmd) | |
333 | { | |
334 | default: | |
335 | return -ENOIOCTLCMD; | |
336 | ||
337 | case WDIOC_GETSUPPORT: | |
338 | return copy_to_user(uarg.ident, &ident, | |
339 | sizeof(ident)) ? -EFAULT : 0; | |
340 | ||
341 | case WDIOC_GETSTATUS: | |
342 | wdt977_get_status(&status); | |
343 | return put_user(status, uarg.i); | |
344 | ||
345 | case WDIOC_GETBOOTSTATUS: | |
346 | return put_user(0, uarg.i); | |
347 | ||
348 | case WDIOC_KEEPALIVE: | |
349 | wdt977_keepalive(); | |
350 | return 0; | |
351 | ||
352 | case WDIOC_SETOPTIONS: | |
353 | if (get_user (new_options, uarg.i)) | |
354 | return -EFAULT; | |
355 | ||
356 | if (new_options & WDIOS_DISABLECARD) { | |
357 | wdt977_stop(); | |
358 | retval = 0; | |
359 | } | |
360 | ||
361 | if (new_options & WDIOS_ENABLECARD) { | |
362 | wdt977_start(); | |
363 | retval = 0; | |
364 | } | |
365 | ||
366 | return retval; | |
367 | ||
368 | case WDIOC_SETTIMEOUT: | |
369 | if (get_user(new_timeout, uarg.i)) | |
370 | return -EFAULT; | |
371 | ||
372 | if (wdt977_set_timeout(new_timeout)) | |
373 | return -EINVAL; | |
374 | ||
375 | wdt977_keepalive(); | |
376 | /* Fall */ | |
377 | ||
378 | case WDIOC_GETTIMEOUT: | |
379 | return put_user(timeout, uarg.i); | |
380 | ||
381 | } | |
382 | } | |
383 | ||
384 | static int wdt977_notify_sys(struct notifier_block *this, unsigned long code, | |
385 | void *unused) | |
386 | { | |
387 | if(code==SYS_DOWN || code==SYS_HALT) | |
388 | wdt977_stop(); | |
389 | return NOTIFY_DONE; | |
390 | } | |
391 | ||
392 | static struct file_operations wdt977_fops= | |
393 | { | |
394 | .owner = THIS_MODULE, | |
395 | .llseek = no_llseek, | |
396 | .write = wdt977_write, | |
397 | .ioctl = wdt977_ioctl, | |
398 | .open = wdt977_open, | |
399 | .release = wdt977_release, | |
400 | }; | |
401 | ||
402 | static struct miscdevice wdt977_miscdev= | |
403 | { | |
404 | .minor = WATCHDOG_MINOR, | |
405 | .name = "watchdog", | |
406 | .fops = &wdt977_fops, | |
407 | }; | |
408 | ||
409 | static struct notifier_block wdt977_notifier = { | |
410 | .notifier_call = wdt977_notify_sys, | |
411 | }; | |
412 | ||
413 | static int __init nwwatchdog_init(void) | |
414 | { | |
415 | int retval; | |
416 | if (!machine_is_netwinder()) | |
417 | return -ENODEV; | |
418 | ||
419 | /* Check that the timeout value is within it's range ; if not reset to the default */ | |
420 | if (wdt977_set_timeout(timeout)) { | |
421 | wdt977_set_timeout(DEFAULT_TIMEOUT); | |
422 | printk(KERN_INFO PFX "timeout value must be 60<timeout<15300, using %d\n", | |
423 | DEFAULT_TIMEOUT); | |
424 | } | |
425 | ||
426 | retval = register_reboot_notifier(&wdt977_notifier); | |
427 | if (retval) { | |
428 | printk(KERN_ERR PFX "cannot register reboot notifier (err=%d)\n", | |
429 | retval); | |
430 | return retval; | |
431 | } | |
432 | ||
433 | retval = misc_register(&wdt977_miscdev); | |
434 | if (retval) { | |
435 | printk(KERN_ERR PFX "cannot register miscdev on minor=%d (err=%d)\n", | |
436 | WATCHDOG_MINOR, retval); | |
437 | unregister_reboot_notifier(&wdt977_notifier); | |
438 | return retval; | |
439 | } | |
440 | ||
441 | printk(KERN_INFO PFX "initialized. timeout=%d sec (nowayout=%d, testmode = %i)\n", | |
442 | timeout, nowayout, testmode); | |
443 | ||
444 | return 0; | |
445 | } | |
446 | ||
447 | static void __exit nwwatchdog_exit(void) | |
448 | { | |
449 | misc_deregister(&wdt977_miscdev); | |
450 | unregister_reboot_notifier(&wdt977_notifier); | |
451 | } | |
452 | ||
453 | module_init(nwwatchdog_init); | |
454 | module_exit(nwwatchdog_exit); | |
455 | ||
456 | MODULE_AUTHOR("Woody Suwalski <woody@netwinder.org>"); | |
457 | MODULE_DESCRIPTION("W83977AF Watchdog driver"); | |
458 | MODULE_LICENSE("GPL"); | |
459 | MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR); |