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Diffstat (limited to 'drivers/char/watchdog/w83977f_wdt.c')
-rw-r--r--drivers/char/watchdog/w83977f_wdt.c543
1 files changed, 543 insertions, 0 deletions
diff --git a/drivers/char/watchdog/w83977f_wdt.c b/drivers/char/watchdog/w83977f_wdt.c
new file mode 100644
index 000000000000..a7ff64c8921f
--- /dev/null
+++ b/drivers/char/watchdog/w83977f_wdt.c
@@ -0,0 +1,543 @@
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>
20#include <linux/config.h>
21#include <linux/types.h>
22#include <linux/kernel.h>
23#include <linux/fs.h>
24#include <linux/miscdevice.h>
25#include <linux/init.h>
26#include <linux/ioport.h>
27#include <linux/watchdog.h>
28#include <linux/notifier.h>
29#include <linux/reboot.h>
30
31#include <asm/io.h>
32#include <asm/system.h>
33#include <asm/uaccess.h>
34
35#define WATCHDOG_VERSION "1.00"
36#define WATCHDOG_NAME "W83977F WDT"
37#define PFX WATCHDOG_NAME ": "
38#define DRIVER_VERSION WATCHDOG_NAME " driver, v" WATCHDOG_VERSION "\n"
39
40#define IO_INDEX_PORT 0x3F0
41#define IO_DATA_PORT (IO_INDEX_PORT+1)
42
43#define UNLOCK_DATA 0x87
44#define LOCK_DATA 0xAA
45#define DEVICE_REGISTER 0x07
46
47#define DEFAULT_TIMEOUT 45 /* default timeout in seconds */
48
49static int timeout = DEFAULT_TIMEOUT;
50static int timeoutW; /* timeout in watchdog counter units */
51static unsigned long timer_alive;
52static int testmode;
53static char expect_close;
54static spinlock_t spinlock;
55
56module_param(timeout, int, 0);
57MODULE_PARM_DESC(timeout,"Watchdog timeout in seconds (15..7635), default=" __MODULE_STRING(DEFAULT_TIMEOUT) ")");
58module_param(testmode, int, 0);
59MODULE_PARM_DESC(testmode,"Watchdog testmode (1 = no reboot), default=0");
60
61static int nowayout = WATCHDOG_NOWAYOUT;
62module_param(nowayout, int, 0);
63MODULE_PARM_DESC(nowayout, "Watchdog cannot be stopped once started (default=CONFIG_WATCHDOG_NOWAYOUT)");
64
65/*
66 * Start the watchdog
67 */
68
69static int wdt_start(void)
70{
71 unsigned long flags;
72
73 spin_lock_irqsave(&spinlock, flags);
74
75 /* Unlock the SuperIO chip */
76 outb_p(UNLOCK_DATA,IO_INDEX_PORT);
77 outb_p(UNLOCK_DATA,IO_INDEX_PORT);
78
79 /*
80 * Select device Aux2 (device=8) to set watchdog regs F2, F3 and F4.
81 * F2 has the timeout in watchdog counter units.
82 * F3 is set to enable watchdog LED blink at timeout.
83 * F4 is used to just clear the TIMEOUT'ed state (bit 0).
84 */
85 outb_p(DEVICE_REGISTER,IO_INDEX_PORT);
86 outb_p(0x08,IO_DATA_PORT);
87 outb_p(0xF2,IO_INDEX_PORT);
88 outb_p(timeoutW,IO_DATA_PORT);
89 outb_p(0xF3,IO_INDEX_PORT);
90 outb_p(0x08,IO_DATA_PORT);
91 outb_p(0xF4,IO_INDEX_PORT);
92 outb_p(0x00,IO_DATA_PORT);
93
94 /* Set device Aux2 active */
95 outb_p(0x30,IO_INDEX_PORT);
96 outb_p(0x01,IO_DATA_PORT);
97
98 /*
99 * Select device Aux1 (dev=7) to set GP16 as the watchdog output
100 * (in reg E6) and GP13 as the watchdog LED output (in reg E3).
101 * Map GP16 at pin 119.
102 * In test mode watch the bit 0 on F4 to indicate "triggered" or
103 * check watchdog LED on SBC.
104 */
105 outb_p(DEVICE_REGISTER,IO_INDEX_PORT);
106 outb_p(0x07,IO_DATA_PORT);
107 if (!testmode)
108 {
109 unsigned pin_map;
110
111 outb_p(0xE6,IO_INDEX_PORT);
112 outb_p(0x0A,IO_DATA_PORT);
113 outb_p(0x2C,IO_INDEX_PORT);
114 pin_map = inb_p(IO_DATA_PORT);
115 pin_map |= 0x10;
116 pin_map &= ~(0x20);
117 outb_p(0x2C,IO_INDEX_PORT);
118 outb_p(pin_map,IO_DATA_PORT);
119 }
120 outb_p(0xE3,IO_INDEX_PORT);
121 outb_p(0x08,IO_DATA_PORT);
122
123 /* Set device Aux1 active */
124 outb_p(0x30,IO_INDEX_PORT);
125 outb_p(0x01,IO_DATA_PORT);
126
127 /* Lock the SuperIO chip */
128 outb_p(LOCK_DATA,IO_INDEX_PORT);
129
130 spin_unlock_irqrestore(&spinlock, flags);
131
132 printk(KERN_INFO PFX "activated.\n");
133
134 return 0;
135}
136
137/*
138 * Stop the watchdog
139 */
140
141static int wdt_stop(void)
142{
143 unsigned long flags;
144
145 spin_lock_irqsave(&spinlock, flags);
146
147 /* Unlock the SuperIO chip */
148 outb_p(UNLOCK_DATA,IO_INDEX_PORT);
149 outb_p(UNLOCK_DATA,IO_INDEX_PORT);
150
151 /*
152 * Select device Aux2 (device=8) to set watchdog regs F2, F3 and F4.
153 * F2 is reset to its default value (watchdog timer disabled).
154 * F3 is reset to its default state.
155 * F4 clears the TIMEOUT'ed state (bit 0) - back to default.
156 */
157 outb_p(DEVICE_REGISTER,IO_INDEX_PORT);
158 outb_p(0x08,IO_DATA_PORT);
159 outb_p(0xF2,IO_INDEX_PORT);
160 outb_p(0xFF,IO_DATA_PORT);
161 outb_p(0xF3,IO_INDEX_PORT);
162 outb_p(0x00,IO_DATA_PORT);
163 outb_p(0xF4,IO_INDEX_PORT);
164 outb_p(0x00,IO_DATA_PORT);
165 outb_p(0xF2,IO_INDEX_PORT);
166 outb_p(0x00,IO_DATA_PORT);
167
168 /*
169 * Select device Aux1 (dev=7) to set GP16 (in reg E6) and
170 * Gp13 (in reg E3) as inputs.
171 */
172 outb_p(DEVICE_REGISTER,IO_INDEX_PORT);
173 outb_p(0x07,IO_DATA_PORT);
174 if (!testmode)
175 {
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 printk(KERN_INFO PFX "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
197static 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
225static int wdt_set_timeout(int t)
226{
227 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
257static 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
291static 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
304static 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 {
312 wdt_stop();
313 clear_bit(0, &timer_alive);
314 } else {
315 wdt_keepalive();
316 printk(KERN_CRIT PFX "unexpected close, not stopping watchdog!\n");
317 }
318 expect_close = 0;
319 return 0;
320}
321
322/*
323 * wdt_write:
324 * @file: file handle to the watchdog
325 * @buf: buffer to write (unused as data does not matter here
326 * @count: count of bytes
327 * @ppos: pointer to the position to write. No seeks allowed
328 *
329 * A write to a watchdog device is defined as a keepalive signal. Any
330 * write of data will do, as we we don't define content meaning.
331 */
332
333static ssize_t wdt_write(struct file *file, const char __user *buf,
334 size_t count, loff_t *ppos)
335{
336 /* See if we got the magic character 'V' and reload the timer */
337 if(count)
338 {
339 if (!nowayout)
340 {
341 size_t ofs;
342
343 /* note: just in case someone wrote the magic character long ago */
344 expect_close = 0;
345
346 /* scan to see whether or not we got the magic character */
347 for(ofs = 0; ofs != count; ofs++)
348 {
349 char c;
350 if (get_user(c, buf + ofs))
351 return -EFAULT;
352 if (c == 'V') {
353 expect_close = 42;
354 }
355 }
356 }
357
358 /* someone wrote to us, we should restart timer */
359 wdt_keepalive();
360 }
361 return count;
362}
363
364/*
365 * wdt_ioctl:
366 * @inode: inode of the device
367 * @file: file handle to the device
368 * @cmd: watchdog command
369 * @arg: argument pointer
370 *
371 * The watchdog API defines a common set of functions for all watchdogs
372 * according to their available features.
373 */
374
375static struct watchdog_info ident = {
376 .options = WDIOF_SETTIMEOUT | WDIOF_MAGICCLOSE | WDIOF_KEEPALIVEPING,
377 .firmware_version = 1,
378 .identity = WATCHDOG_NAME,
379};
380
381static int wdt_ioctl(struct inode *inode, struct file *file,
382 unsigned int cmd, unsigned long arg)
383{
384 int status;
385 int new_options, retval = -EINVAL;
386 int new_timeout;
387 union {
388 struct watchdog_info __user *ident;
389 int __user *i;
390 } uarg;
391
392 uarg.i = (int __user *)arg;
393
394 switch(cmd)
395 {
396 default:
397 return -ENOIOCTLCMD;
398
399 case WDIOC_GETSUPPORT:
400 return copy_to_user(uarg.ident, &ident, sizeof(ident)) ? -EFAULT : 0;
401
402 case WDIOC_GETSTATUS:
403 wdt_get_status(&status);
404 return put_user(status, uarg.i);
405
406 case WDIOC_GETBOOTSTATUS:
407 return put_user(0, uarg.i);
408
409 case WDIOC_KEEPALIVE:
410 wdt_keepalive();
411 return 0;
412
413 case WDIOC_SETOPTIONS:
414 if (get_user (new_options, uarg.i))
415 return -EFAULT;
416
417 if (new_options & WDIOS_DISABLECARD) {
418 wdt_stop();
419 retval = 0;
420 }
421
422 if (new_options & WDIOS_ENABLECARD) {
423 wdt_start();
424 retval = 0;
425 }
426
427 return retval;
428
429 case WDIOC_SETTIMEOUT:
430 if (get_user(new_timeout, uarg.i))
431 return -EFAULT;
432
433 if (wdt_set_timeout(new_timeout))
434 return -EINVAL;
435
436 wdt_keepalive();
437 /* Fall */
438
439 case WDIOC_GETTIMEOUT:
440 return put_user(timeout, uarg.i);
441
442 }
443}
444
445static int wdt_notify_sys(struct notifier_block *this, unsigned long code,
446 void *unused)
447{
448 if (code==SYS_DOWN || code==SYS_HALT)
449 wdt_stop();
450 return NOTIFY_DONE;
451}
452
453static struct file_operations wdt_fops=
454{
455 .owner = THIS_MODULE,
456 .llseek = no_llseek,
457 .write = wdt_write,
458 .ioctl = wdt_ioctl,
459 .open = wdt_open,
460 .release = wdt_release,
461};
462
463static struct miscdevice wdt_miscdev=
464{
465 .minor = WATCHDOG_MINOR,
466 .name = "watchdog",
467 .fops = &wdt_fops,
468};
469
470static struct notifier_block wdt_notifier = {
471 .notifier_call = wdt_notify_sys,
472};
473
474static int __init w83977f_wdt_init(void)
475{
476 int rc;
477
478 printk(KERN_INFO PFX DRIVER_VERSION);
479
480 spin_lock_init(&spinlock);
481
482 /*
483 * Check that the timeout value is within it's range ;
484 * if not reset to the default
485 */
486 if (wdt_set_timeout(timeout)) {
487 wdt_set_timeout(DEFAULT_TIMEOUT);
488 printk(KERN_INFO PFX "timeout value must be 15<=timeout<=7635, using %d\n",
489 DEFAULT_TIMEOUT);
490 }
491
492 if (!request_region(IO_INDEX_PORT, 2, WATCHDOG_NAME))
493 {
494 printk(KERN_ERR PFX "I/O address 0x%04x already in use\n",
495 IO_INDEX_PORT);
496 rc = -EIO;
497 goto err_out;
498 }
499
500 rc = misc_register(&wdt_miscdev);
501 if (rc)
502 {
503 printk(KERN_ERR PFX "cannot register miscdev on minor=%d (err=%d)\n",
504 wdt_miscdev.minor, rc);
505 goto err_out_region;
506 }
507
508 rc = register_reboot_notifier(&wdt_notifier);
509 if (rc)
510 {
511 printk(KERN_ERR PFX "cannot register reboot notifier (err=%d)\n",
512 rc);
513 goto err_out_miscdev;
514 }
515
516 printk(KERN_INFO PFX "initialized. timeout=%d sec (nowayout=%d testmode=%d)\n",
517 timeout, nowayout, testmode);
518
519 return 0;
520
521err_out_miscdev:
522 misc_deregister(&wdt_miscdev);
523err_out_region:
524 release_region(IO_INDEX_PORT,2);
525err_out:
526 return rc;
527}
528
529static void __exit w83977f_wdt_exit(void)
530{
531 wdt_stop();
532 misc_deregister(&wdt_miscdev);
533 unregister_reboot_notifier(&wdt_notifier);
534 release_region(IO_INDEX_PORT,2);
535}
536
537module_init(w83977f_wdt_init);
538module_exit(w83977f_wdt_exit);
539
540MODULE_AUTHOR("Jose Goncalves <jose.goncalves@inov.pt>");
541MODULE_DESCRIPTION("Driver for watchdog timer in W83977F I/O chip");
542MODULE_LICENSE("GPL");
543MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR);