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