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b4cc4aa2 JMG |
1 | /* |
2 | * W83977F Watchdog Timer Driver for Winbond W83977F I/O Chip | |
3 | * | |
4 | * (c) Copyright 2005 Jose Goncalves <jose.goncalves@inov.pt> | |
5 | * | |
6 | * Based on w83877f_wdt.c by Scott Jennings, | |
7 | * and wdt977.c by Woody Suwalski | |
8 | * | |
9 | * ----------------------- | |
10 | * | |
11 | * This program is free software; you can redistribute it and/or | |
12 | * modify it under the terms of the GNU General Public License | |
13 | * as published by the Free Software Foundation; either version | |
14 | * 2 of the License, or (at your option) any later version. | |
15 | * | |
16 | */ | |
17 | ||
18 | #include <linux/module.h> | |
19 | #include <linux/moduleparam.h> | |
b4cc4aa2 JMG |
20 | #include <linux/types.h> |
21 | #include <linux/kernel.h> | |
22 | #include <linux/fs.h> | |
23 | #include <linux/miscdevice.h> | |
24 | #include <linux/init.h> | |
25 | #include <linux/ioport.h> | |
26 | #include <linux/watchdog.h> | |
27 | #include <linux/notifier.h> | |
28 | #include <linux/reboot.h> | |
29 | ||
30 | #include <asm/io.h> | |
31 | #include <asm/system.h> | |
32 | #include <asm/uaccess.h> | |
33 | ||
34 | #define WATCHDOG_VERSION "1.00" | |
35 | #define WATCHDOG_NAME "W83977F WDT" | |
36 | #define PFX WATCHDOG_NAME ": " | |
37 | #define DRIVER_VERSION WATCHDOG_NAME " driver, v" WATCHDOG_VERSION "\n" | |
38 | ||
39 | #define IO_INDEX_PORT 0x3F0 | |
40 | #define IO_DATA_PORT (IO_INDEX_PORT+1) | |
41 | ||
42 | #define UNLOCK_DATA 0x87 | |
43 | #define LOCK_DATA 0xAA | |
44 | #define DEVICE_REGISTER 0x07 | |
45 | ||
46 | #define DEFAULT_TIMEOUT 45 /* default timeout in seconds */ | |
47 | ||
48 | static int timeout = DEFAULT_TIMEOUT; | |
49 | static int timeoutW; /* timeout in watchdog counter units */ | |
50 | static unsigned long timer_alive; | |
51 | static int testmode; | |
52 | static char expect_close; | |
c7dfd0cc | 53 | static DEFINE_SPINLOCK(spinlock); |
b4cc4aa2 JMG |
54 | |
55 | module_param(timeout, int, 0); | |
56 | MODULE_PARM_DESC(timeout,"Watchdog timeout in seconds (15..7635), default=" __MODULE_STRING(DEFAULT_TIMEOUT) ")"); | |
57 | module_param(testmode, int, 0); | |
58 | MODULE_PARM_DESC(testmode,"Watchdog testmode (1 = no reboot), default=0"); | |
59 | ||
3908bb18 | 60 | static int nowayout = WATCHDOG_NOWAYOUT; |
b4cc4aa2 | 61 | module_param(nowayout, int, 0); |
bffda5c8 | 62 | MODULE_PARM_DESC(nowayout, "Watchdog cannot be stopped once started (default=" __MODULE_STRING(WATCHDOG_NOWAYOUT) ")"); |
b4cc4aa2 JMG |
63 | |
64 | /* | |
65 | * Start the watchdog | |
66 | */ | |
67 | ||
68 | static int wdt_start(void) | |
69 | { | |
70 | unsigned long flags; | |
71 | ||
72 | spin_lock_irqsave(&spinlock, flags); | |
73 | ||
74 | /* Unlock the SuperIO chip */ | |
75 | outb_p(UNLOCK_DATA,IO_INDEX_PORT); | |
76 | outb_p(UNLOCK_DATA,IO_INDEX_PORT); | |
77 | ||
78 | /* | |
79 | * Select device Aux2 (device=8) to set watchdog regs F2, F3 and F4. | |
80 | * F2 has the timeout in watchdog counter units. | |
81 | * F3 is set to enable watchdog LED blink at timeout. | |
82 | * F4 is used to just clear the TIMEOUT'ed state (bit 0). | |
83 | */ | |
84 | outb_p(DEVICE_REGISTER,IO_INDEX_PORT); | |
85 | outb_p(0x08,IO_DATA_PORT); | |
86 | outb_p(0xF2,IO_INDEX_PORT); | |
87 | outb_p(timeoutW,IO_DATA_PORT); | |
88 | outb_p(0xF3,IO_INDEX_PORT); | |
89 | outb_p(0x08,IO_DATA_PORT); | |
90 | outb_p(0xF4,IO_INDEX_PORT); | |
91 | outb_p(0x00,IO_DATA_PORT); | |
92 | ||
93 | /* Set device Aux2 active */ | |
94 | outb_p(0x30,IO_INDEX_PORT); | |
95 | outb_p(0x01,IO_DATA_PORT); | |
96 | ||
97 | /* | |
98 | * Select device Aux1 (dev=7) to set GP16 as the watchdog output | |
99 | * (in reg E6) and GP13 as the watchdog LED output (in reg E3). | |
100 | * Map GP16 at pin 119. | |
101 | * In test mode watch the bit 0 on F4 to indicate "triggered" or | |
102 | * check watchdog LED on SBC. | |
103 | */ | |
104 | outb_p(DEVICE_REGISTER,IO_INDEX_PORT); | |
105 | outb_p(0x07,IO_DATA_PORT); | |
106 | if (!testmode) | |
107 | { | |
108 | unsigned pin_map; | |
109 | ||
110 | outb_p(0xE6,IO_INDEX_PORT); | |
111 | outb_p(0x0A,IO_DATA_PORT); | |
112 | outb_p(0x2C,IO_INDEX_PORT); | |
113 | pin_map = inb_p(IO_DATA_PORT); | |
114 | pin_map |= 0x10; | |
115 | pin_map &= ~(0x20); | |
116 | outb_p(0x2C,IO_INDEX_PORT); | |
117 | outb_p(pin_map,IO_DATA_PORT); | |
118 | } | |
119 | outb_p(0xE3,IO_INDEX_PORT); | |
120 | outb_p(0x08,IO_DATA_PORT); | |
121 | ||
122 | /* Set device Aux1 active */ | |
123 | outb_p(0x30,IO_INDEX_PORT); | |
124 | outb_p(0x01,IO_DATA_PORT); | |
125 | ||
126 | /* Lock the SuperIO chip */ | |
127 | outb_p(LOCK_DATA,IO_INDEX_PORT); | |
128 | ||
129 | spin_unlock_irqrestore(&spinlock, flags); | |
130 | ||
131 | printk(KERN_INFO PFX "activated.\n"); | |
132 | ||
133 | return 0; | |
134 | } | |
135 | ||
136 | /* | |
137 | * Stop the watchdog | |
138 | */ | |
139 | ||
140 | static int wdt_stop(void) | |
141 | { | |
142 | unsigned long flags; | |
143 | ||
144 | spin_lock_irqsave(&spinlock, flags); | |
145 | ||
146 | /* Unlock the SuperIO chip */ | |
147 | outb_p(UNLOCK_DATA,IO_INDEX_PORT); | |
148 | outb_p(UNLOCK_DATA,IO_INDEX_PORT); | |
149 | ||
150 | /* | |
151 | * Select device Aux2 (device=8) to set watchdog regs F2, F3 and F4. | |
152 | * F2 is reset to its default value (watchdog timer disabled). | |
153 | * F3 is reset to its default state. | |
154 | * F4 clears the TIMEOUT'ed state (bit 0) - back to default. | |
155 | */ | |
156 | outb_p(DEVICE_REGISTER,IO_INDEX_PORT); | |
157 | outb_p(0x08,IO_DATA_PORT); | |
158 | outb_p(0xF2,IO_INDEX_PORT); | |
159 | outb_p(0xFF,IO_DATA_PORT); | |
160 | outb_p(0xF3,IO_INDEX_PORT); | |
161 | outb_p(0x00,IO_DATA_PORT); | |
162 | outb_p(0xF4,IO_INDEX_PORT); | |
163 | outb_p(0x00,IO_DATA_PORT); | |
164 | outb_p(0xF2,IO_INDEX_PORT); | |
165 | outb_p(0x00,IO_DATA_PORT); | |
166 | ||
167 | /* | |
168 | * Select device Aux1 (dev=7) to set GP16 (in reg E6) and | |
169 | * Gp13 (in reg E3) as inputs. | |
170 | */ | |
171 | outb_p(DEVICE_REGISTER,IO_INDEX_PORT); | |
172 | outb_p(0x07,IO_DATA_PORT); | |
173 | if (!testmode) | |
174 | { | |
175 | outb_p(0xE6,IO_INDEX_PORT); | |
176 | outb_p(0x01,IO_DATA_PORT); | |
177 | } | |
178 | outb_p(0xE3,IO_INDEX_PORT); | |
179 | outb_p(0x01,IO_DATA_PORT); | |
180 | ||
181 | /* Lock the SuperIO chip */ | |
182 | outb_p(LOCK_DATA,IO_INDEX_PORT); | |
183 | ||
184 | spin_unlock_irqrestore(&spinlock, flags); | |
185 | ||
186 | printk(KERN_INFO PFX "shutdown.\n"); | |
187 | ||
188 | return 0; | |
189 | } | |
190 | ||
191 | /* | |
192 | * Send a keepalive ping to the watchdog | |
193 | * This is done by simply re-writing the timeout to reg. 0xF2 | |
194 | */ | |
195 | ||
196 | static int wdt_keepalive(void) | |
197 | { | |
198 | unsigned long flags; | |
199 | ||
200 | spin_lock_irqsave(&spinlock, flags); | |
201 | ||
202 | /* Unlock the SuperIO chip */ | |
203 | outb_p(UNLOCK_DATA,IO_INDEX_PORT); | |
204 | outb_p(UNLOCK_DATA,IO_INDEX_PORT); | |
205 | ||
206 | /* Select device Aux2 (device=8) to kick watchdog reg F2 */ | |
207 | outb_p(DEVICE_REGISTER,IO_INDEX_PORT); | |
208 | outb_p(0x08,IO_DATA_PORT); | |
209 | outb_p(0xF2,IO_INDEX_PORT); | |
210 | outb_p(timeoutW,IO_DATA_PORT); | |
211 | ||
212 | /* Lock the SuperIO chip */ | |
213 | outb_p(LOCK_DATA,IO_INDEX_PORT); | |
214 | ||
215 | spin_unlock_irqrestore(&spinlock, flags); | |
216 | ||
217 | return 0; | |
218 | } | |
219 | ||
220 | /* | |
221 | * Set the watchdog timeout value | |
222 | */ | |
223 | ||
224 | static int wdt_set_timeout(int t) | |
225 | { | |
226 | int tmrval; | |
227 | ||
228 | /* | |
229 | * Convert seconds to watchdog counter time units, rounding up. | |
230 | * On PCM-5335 watchdog units are 30 seconds/step with 15 sec startup | |
231 | * value. This information is supplied in the PCM-5335 manual and was | |
232 | * checked by me on a real board. This is a bit strange because W83977f | |
233 | * datasheet says counter unit is in minutes! | |
234 | */ | |
235 | if (t < 15) | |
236 | return -EINVAL; | |
237 | ||
238 | tmrval = ((t + 15) + 29) / 30; | |
239 | ||
240 | if (tmrval > 255) | |
241 | return -EINVAL; | |
242 | ||
243 | /* | |
244 | * timeout is the timeout in seconds, | |
245 | * timeoutW is the timeout in watchdog counter units. | |
246 | */ | |
247 | timeoutW = tmrval; | |
248 | timeout = (timeoutW * 30) - 15; | |
249 | return 0; | |
250 | } | |
251 | ||
252 | /* | |
253 | * Get the watchdog status | |
254 | */ | |
255 | ||
256 | static int wdt_get_status(int *status) | |
257 | { | |
258 | int new_status; | |
259 | unsigned long flags; | |
260 | ||
261 | spin_lock_irqsave(&spinlock, flags); | |
262 | ||
263 | /* Unlock the SuperIO chip */ | |
264 | outb_p(UNLOCK_DATA,IO_INDEX_PORT); | |
265 | outb_p(UNLOCK_DATA,IO_INDEX_PORT); | |
266 | ||
267 | /* Select device Aux2 (device=8) to read watchdog reg F4 */ | |
268 | outb_p(DEVICE_REGISTER,IO_INDEX_PORT); | |
269 | outb_p(0x08,IO_DATA_PORT); | |
270 | outb_p(0xF4,IO_INDEX_PORT); | |
271 | new_status = inb_p(IO_DATA_PORT); | |
272 | ||
273 | /* Lock the SuperIO chip */ | |
274 | outb_p(LOCK_DATA,IO_INDEX_PORT); | |
275 | ||
276 | spin_unlock_irqrestore(&spinlock, flags); | |
277 | ||
278 | *status = 0; | |
279 | if (new_status & 1) | |
280 | *status |= WDIOF_CARDRESET; | |
281 | ||
282 | return 0; | |
283 | } | |
284 | ||
285 | ||
286 | /* | |
287 | * /dev/watchdog handling | |
288 | */ | |
289 | ||
290 | static int wdt_open(struct inode *inode, struct file *file) | |
291 | { | |
292 | /* If the watchdog is alive we don't need to start it again */ | |
293 | if( test_and_set_bit(0, &timer_alive) ) | |
294 | return -EBUSY; | |
295 | ||
296 | if (nowayout) | |
297 | __module_get(THIS_MODULE); | |
298 | ||
299 | wdt_start(); | |
300 | return nonseekable_open(inode, file); | |
301 | } | |
302 | ||
303 | static int wdt_release(struct inode *inode, struct file *file) | |
304 | { | |
305 | /* | |
306 | * Shut off the timer. | |
307 | * Lock it in if it's a module and we set nowayout | |
308 | */ | |
309 | if (expect_close == 42) | |
310 | { | |
311 | wdt_stop(); | |
312 | clear_bit(0, &timer_alive); | |
313 | } else { | |
314 | wdt_keepalive(); | |
315 | printk(KERN_CRIT PFX "unexpected close, not stopping watchdog!\n"); | |
316 | } | |
317 | expect_close = 0; | |
318 | return 0; | |
319 | } | |
320 | ||
321 | /* | |
322 | * wdt_write: | |
323 | * @file: file handle to the watchdog | |
324 | * @buf: buffer to write (unused as data does not matter here | |
325 | * @count: count of bytes | |
326 | * @ppos: pointer to the position to write. No seeks allowed | |
327 | * | |
328 | * A write to a watchdog device is defined as a keepalive signal. Any | |
329 | * write of data will do, as we we don't define content meaning. | |
330 | */ | |
331 | ||
332 | static ssize_t wdt_write(struct file *file, const char __user *buf, | |
333 | size_t count, loff_t *ppos) | |
334 | { | |
335 | /* See if we got the magic character 'V' and reload the timer */ | |
336 | if(count) | |
337 | { | |
338 | if (!nowayout) | |
339 | { | |
340 | size_t ofs; | |
341 | ||
342 | /* note: just in case someone wrote the magic character long ago */ | |
343 | expect_close = 0; | |
344 | ||
345 | /* scan to see whether or not we got the magic character */ | |
346 | for(ofs = 0; ofs != count; ofs++) | |
347 | { | |
348 | char c; | |
349 | if (get_user(c, buf + ofs)) | |
350 | return -EFAULT; | |
351 | if (c == 'V') { | |
352 | expect_close = 42; | |
353 | } | |
354 | } | |
355 | } | |
356 | ||
357 | /* someone wrote to us, we should restart timer */ | |
358 | wdt_keepalive(); | |
359 | } | |
360 | return count; | |
361 | } | |
362 | ||
363 | /* | |
364 | * wdt_ioctl: | |
365 | * @inode: inode of the device | |
366 | * @file: file handle to the device | |
367 | * @cmd: watchdog command | |
368 | * @arg: argument pointer | |
369 | * | |
370 | * The watchdog API defines a common set of functions for all watchdogs | |
371 | * according to their available features. | |
372 | */ | |
373 | ||
374 | static struct watchdog_info ident = { | |
375 | .options = WDIOF_SETTIMEOUT | WDIOF_MAGICCLOSE | WDIOF_KEEPALIVEPING, | |
376 | .firmware_version = 1, | |
377 | .identity = WATCHDOG_NAME, | |
378 | }; | |
379 | ||
380 | static int wdt_ioctl(struct inode *inode, struct file *file, | |
381 | unsigned int cmd, unsigned long arg) | |
382 | { | |
383 | int status; | |
384 | int new_options, retval = -EINVAL; | |
385 | int new_timeout; | |
386 | union { | |
387 | struct watchdog_info __user *ident; | |
388 | int __user *i; | |
389 | } uarg; | |
390 | ||
391 | uarg.i = (int __user *)arg; | |
392 | ||
393 | switch(cmd) | |
394 | { | |
395 | default: | |
795b89d2 | 396 | return -ENOTTY; |
b4cc4aa2 JMG |
397 | |
398 | case WDIOC_GETSUPPORT: | |
399 | return copy_to_user(uarg.ident, &ident, sizeof(ident)) ? -EFAULT : 0; | |
400 | ||
401 | case WDIOC_GETSTATUS: | |
402 | wdt_get_status(&status); | |
403 | return put_user(status, uarg.i); | |
404 | ||
405 | case WDIOC_GETBOOTSTATUS: | |
406 | return put_user(0, uarg.i); | |
407 | ||
408 | case WDIOC_KEEPALIVE: | |
409 | wdt_keepalive(); | |
410 | return 0; | |
411 | ||
412 | case WDIOC_SETOPTIONS: | |
413 | if (get_user (new_options, uarg.i)) | |
414 | return -EFAULT; | |
415 | ||
416 | if (new_options & WDIOS_DISABLECARD) { | |
417 | wdt_stop(); | |
418 | retval = 0; | |
419 | } | |
420 | ||
421 | if (new_options & WDIOS_ENABLECARD) { | |
422 | wdt_start(); | |
423 | retval = 0; | |
424 | } | |
425 | ||
426 | return retval; | |
427 | ||
428 | case WDIOC_SETTIMEOUT: | |
429 | if (get_user(new_timeout, uarg.i)) | |
430 | return -EFAULT; | |
431 | ||
432 | if (wdt_set_timeout(new_timeout)) | |
433 | return -EINVAL; | |
434 | ||
435 | wdt_keepalive(); | |
436 | /* Fall */ | |
437 | ||
438 | case WDIOC_GETTIMEOUT: | |
439 | return put_user(timeout, uarg.i); | |
440 | ||
441 | } | |
442 | } | |
443 | ||
444 | static int wdt_notify_sys(struct notifier_block *this, unsigned long code, | |
445 | void *unused) | |
446 | { | |
447 | if (code==SYS_DOWN || code==SYS_HALT) | |
448 | wdt_stop(); | |
449 | return NOTIFY_DONE; | |
450 | } | |
451 | ||
62322d25 | 452 | static const struct file_operations wdt_fops= |
b4cc4aa2 JMG |
453 | { |
454 | .owner = THIS_MODULE, | |
455 | .llseek = no_llseek, | |
456 | .write = wdt_write, | |
457 | .ioctl = wdt_ioctl, | |
458 | .open = wdt_open, | |
459 | .release = wdt_release, | |
460 | }; | |
461 | ||
462 | static struct miscdevice wdt_miscdev= | |
463 | { | |
464 | .minor = WATCHDOG_MINOR, | |
465 | .name = "watchdog", | |
466 | .fops = &wdt_fops, | |
467 | }; | |
468 | ||
469 | static struct notifier_block wdt_notifier = { | |
470 | .notifier_call = wdt_notify_sys, | |
471 | }; | |
472 | ||
473 | static int __init w83977f_wdt_init(void) | |
474 | { | |
475 | int rc; | |
476 | ||
477 | printk(KERN_INFO PFX DRIVER_VERSION); | |
478 | ||
b4cc4aa2 JMG |
479 | /* |
480 | * Check that the timeout value is within it's range ; | |
481 | * if not reset to the default | |
482 | */ | |
483 | if (wdt_set_timeout(timeout)) { | |
484 | wdt_set_timeout(DEFAULT_TIMEOUT); | |
485 | printk(KERN_INFO PFX "timeout value must be 15<=timeout<=7635, using %d\n", | |
486 | DEFAULT_TIMEOUT); | |
487 | } | |
488 | ||
489 | if (!request_region(IO_INDEX_PORT, 2, WATCHDOG_NAME)) | |
490 | { | |
491 | printk(KERN_ERR PFX "I/O address 0x%04x already in use\n", | |
492 | IO_INDEX_PORT); | |
493 | rc = -EIO; | |
494 | goto err_out; | |
495 | } | |
496 | ||
c6cb13ae | 497 | rc = register_reboot_notifier(&wdt_notifier); |
b4cc4aa2 JMG |
498 | if (rc) |
499 | { | |
c6cb13ae WVS |
500 | printk(KERN_ERR PFX "cannot register reboot notifier (err=%d)\n", |
501 | rc); | |
b4cc4aa2 JMG |
502 | goto err_out_region; |
503 | } | |
504 | ||
c6cb13ae | 505 | rc = misc_register(&wdt_miscdev); |
b4cc4aa2 JMG |
506 | if (rc) |
507 | { | |
c6cb13ae WVS |
508 | printk(KERN_ERR PFX "cannot register miscdev on minor=%d (err=%d)\n", |
509 | wdt_miscdev.minor, rc); | |
510 | goto err_out_reboot; | |
b4cc4aa2 JMG |
511 | } |
512 | ||
513 | printk(KERN_INFO PFX "initialized. timeout=%d sec (nowayout=%d testmode=%d)\n", | |
514 | timeout, nowayout, testmode); | |
515 | ||
516 | return 0; | |
517 | ||
c6cb13ae WVS |
518 | err_out_reboot: |
519 | unregister_reboot_notifier(&wdt_notifier); | |
b4cc4aa2 JMG |
520 | err_out_region: |
521 | release_region(IO_INDEX_PORT,2); | |
522 | err_out: | |
523 | return rc; | |
524 | } | |
525 | ||
526 | static void __exit w83977f_wdt_exit(void) | |
527 | { | |
528 | wdt_stop(); | |
529 | misc_deregister(&wdt_miscdev); | |
530 | unregister_reboot_notifier(&wdt_notifier); | |
531 | release_region(IO_INDEX_PORT,2); | |
532 | } | |
533 | ||
534 | module_init(w83977f_wdt_init); | |
535 | module_exit(w83977f_wdt_exit); | |
536 | ||
537 | MODULE_AUTHOR("Jose Goncalves <jose.goncalves@inov.pt>"); | |
538 | MODULE_DESCRIPTION("Driver for watchdog timer in W83977F I/O chip"); | |
539 | MODULE_LICENSE("GPL"); | |
540 | MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR); |