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