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1// SPDX-License-Identifier: GPL-2.0-or-later
2/*
3 * W83977F Watchdog Timer Driver for Winbond W83977F I/O Chip
4 *
5 * (c) Copyright 2005 Jose Goncalves <jose.goncalves@inov.pt>
6 *
7 * Based on w83877f_wdt.c by Scott Jennings,
8 * and wdt977.c by Woody Suwalski
9 *
10 * -----------------------
11 */
12
13#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
14
15#include <linux/module.h>
16#include <linux/moduleparam.h>
17#include <linux/types.h>
18#include <linux/kernel.h>
19#include <linux/fs.h>
20#include <linux/miscdevice.h>
21#include <linux/init.h>
22#include <linux/ioport.h>
23#include <linux/watchdog.h>
24#include <linux/notifier.h>
25#include <linux/reboot.h>
26#include <linux/uaccess.h>
27#include <linux/io.h>
28
29
30#define WATCHDOG_VERSION "1.00"
31#define WATCHDOG_NAME "W83977F WDT"
32
33#define IO_INDEX_PORT 0x3F0
34#define IO_DATA_PORT (IO_INDEX_PORT+1)
35
36#define UNLOCK_DATA 0x87
37#define LOCK_DATA 0xAA
38#define DEVICE_REGISTER 0x07
39
40#define DEFAULT_TIMEOUT 45 /* default timeout in seconds */
41
42static int timeout = DEFAULT_TIMEOUT;
43static int timeoutW; /* timeout in watchdog counter units */
44static unsigned long timer_alive;
45static int testmode;
46static char expect_close;
47static DEFINE_SPINLOCK(spinlock);
48
49module_param(timeout, int, 0);
50MODULE_PARM_DESC(timeout,
51 "Watchdog timeout in seconds (15..7635), default="
52 __MODULE_STRING(DEFAULT_TIMEOUT) ")");
53module_param(testmode, int, 0);
54MODULE_PARM_DESC(testmode, "Watchdog testmode (1 = no reboot), default=0");
55
56static bool nowayout = WATCHDOG_NOWAYOUT;
57module_param(nowayout, bool, 0);
58MODULE_PARM_DESC(nowayout,
59 "Watchdog cannot be stopped once started (default="
60 __MODULE_STRING(WATCHDOG_NOWAYOUT) ")");
61
62/*
63 * Start the watchdog
64 */
65
66static int wdt_start(void)
67{
68 unsigned long flags;
69
70 spin_lock_irqsave(&spinlock, flags);
71
72 /* Unlock the SuperIO chip */
73 outb_p(UNLOCK_DATA, IO_INDEX_PORT);
74 outb_p(UNLOCK_DATA, IO_INDEX_PORT);
75
76 /*
77 * Select device Aux2 (device=8) to set watchdog regs F2, F3 and F4.
78 * F2 has the timeout in watchdog counter units.
79 * F3 is set to enable watchdog LED blink at timeout.
80 * F4 is used to just clear the TIMEOUT'ed state (bit 0).
81 */
82 outb_p(DEVICE_REGISTER, IO_INDEX_PORT);
83 outb_p(0x08, IO_DATA_PORT);
84 outb_p(0xF2, IO_INDEX_PORT);
85 outb_p(timeoutW, IO_DATA_PORT);
86 outb_p(0xF3, IO_INDEX_PORT);
87 outb_p(0x08, IO_DATA_PORT);
88 outb_p(0xF4, IO_INDEX_PORT);
89 outb_p(0x00, IO_DATA_PORT);
90
91 /* Set device Aux2 active */
92 outb_p(0x30, IO_INDEX_PORT);
93 outb_p(0x01, IO_DATA_PORT);
94
95 /*
96 * Select device Aux1 (dev=7) to set GP16 as the watchdog output
97 * (in reg E6) and GP13 as the watchdog LED output (in reg E3).
98 * Map GP16 at pin 119.
99 * In test mode watch the bit 0 on F4 to indicate "triggered" or
100 * check watchdog LED on SBC.
101 */
102 outb_p(DEVICE_REGISTER, IO_INDEX_PORT);
103 outb_p(0x07, IO_DATA_PORT);
104 if (!testmode) {
105 unsigned pin_map;
106
107 outb_p(0xE6, IO_INDEX_PORT);
108 outb_p(0x0A, IO_DATA_PORT);
109 outb_p(0x2C, IO_INDEX_PORT);
110 pin_map = inb_p(IO_DATA_PORT);
111 pin_map |= 0x10;
112 pin_map &= ~(0x20);
113 outb_p(0x2C, IO_INDEX_PORT);
114 outb_p(pin_map, IO_DATA_PORT);
115 }
116 outb_p(0xE3, IO_INDEX_PORT);
117 outb_p(0x08, IO_DATA_PORT);
118
119 /* Set device Aux1 active */
120 outb_p(0x30, IO_INDEX_PORT);
121 outb_p(0x01, IO_DATA_PORT);
122
123 /* Lock the SuperIO chip */
124 outb_p(LOCK_DATA, IO_INDEX_PORT);
125
126 spin_unlock_irqrestore(&spinlock, flags);
127
128 pr_info("activated\n");
129
130 return 0;
131}
132
133/*
134 * Stop the watchdog
135 */
136
137static int wdt_stop(void)
138{
139 unsigned long flags;
140
141 spin_lock_irqsave(&spinlock, flags);
142
143 /* Unlock the SuperIO chip */
144 outb_p(UNLOCK_DATA, IO_INDEX_PORT);
145 outb_p(UNLOCK_DATA, IO_INDEX_PORT);
146
147 /*
148 * Select device Aux2 (device=8) to set watchdog regs F2, F3 and F4.
149 * F2 is reset to its default value (watchdog timer disabled).
150 * F3 is reset to its default state.
151 * F4 clears the TIMEOUT'ed state (bit 0) - back to default.
152 */
153 outb_p(DEVICE_REGISTER, IO_INDEX_PORT);
154 outb_p(0x08, IO_DATA_PORT);
155 outb_p(0xF2, IO_INDEX_PORT);
156 outb_p(0xFF, IO_DATA_PORT);
157 outb_p(0xF3, IO_INDEX_PORT);
158 outb_p(0x00, IO_DATA_PORT);
159 outb_p(0xF4, IO_INDEX_PORT);
160 outb_p(0x00, IO_DATA_PORT);
161 outb_p(0xF2, IO_INDEX_PORT);
162 outb_p(0x00, IO_DATA_PORT);
163
164 /*
165 * Select device Aux1 (dev=7) to set GP16 (in reg E6) and
166 * Gp13 (in reg E3) as inputs.
167 */
168 outb_p(DEVICE_REGISTER, IO_INDEX_PORT);
169 outb_p(0x07, IO_DATA_PORT);
170 if (!testmode) {
171 outb_p(0xE6, IO_INDEX_PORT);
172 outb_p(0x01, IO_DATA_PORT);
173 }
174 outb_p(0xE3, IO_INDEX_PORT);
175 outb_p(0x01, IO_DATA_PORT);
176
177 /* Lock the SuperIO chip */
178 outb_p(LOCK_DATA, IO_INDEX_PORT);
179
180 spin_unlock_irqrestore(&spinlock, flags);
181
182 pr_info("shutdown\n");
183
184 return 0;
185}
186
187/*
188 * Send a keepalive ping to the watchdog
189 * This is done by simply re-writing the timeout to reg. 0xF2
190 */
191
192static int wdt_keepalive(void)
193{
194 unsigned long flags;
195
196 spin_lock_irqsave(&spinlock, flags);
197
198 /* Unlock the SuperIO chip */
199 outb_p(UNLOCK_DATA, IO_INDEX_PORT);
200 outb_p(UNLOCK_DATA, IO_INDEX_PORT);
201
202 /* Select device Aux2 (device=8) to kick watchdog reg F2 */
203 outb_p(DEVICE_REGISTER, IO_INDEX_PORT);
204 outb_p(0x08, IO_DATA_PORT);
205 outb_p(0xF2, IO_INDEX_PORT);
206 outb_p(timeoutW, IO_DATA_PORT);
207
208 /* Lock the SuperIO chip */
209 outb_p(LOCK_DATA, IO_INDEX_PORT);
210
211 spin_unlock_irqrestore(&spinlock, flags);
212
213 return 0;
214}
215
216/*
217 * Set the watchdog timeout value
218 */
219
220static int wdt_set_timeout(int t)
221{
222 unsigned int tmrval;
223
224 /*
225 * Convert seconds to watchdog counter time units, rounding up.
226 * On PCM-5335 watchdog units are 30 seconds/step with 15 sec startup
227 * value. This information is supplied in the PCM-5335 manual and was
228 * checked by me on a real board. This is a bit strange because W83977f
229 * datasheet says counter unit is in minutes!
230 */
231 if (t < 15)
232 return -EINVAL;
233
234 tmrval = ((t + 15) + 29) / 30;
235
236 if (tmrval > 255)
237 return -EINVAL;
238
239 /*
240 * timeout is the timeout in seconds,
241 * timeoutW is the timeout in watchdog counter units.
242 */
243 timeoutW = tmrval;
244 timeout = (timeoutW * 30) - 15;
245 return 0;
246}
247
248/*
249 * Get the watchdog status
250 */
251
252static int wdt_get_status(int *status)
253{
254 int new_status;
255 unsigned long flags;
256
257 spin_lock_irqsave(&spinlock, flags);
258
259 /* Unlock the SuperIO chip */
260 outb_p(UNLOCK_DATA, IO_INDEX_PORT);
261 outb_p(UNLOCK_DATA, IO_INDEX_PORT);
262
263 /* Select device Aux2 (device=8) to read watchdog reg F4 */
264 outb_p(DEVICE_REGISTER, IO_INDEX_PORT);
265 outb_p(0x08, IO_DATA_PORT);
266 outb_p(0xF4, IO_INDEX_PORT);
267 new_status = inb_p(IO_DATA_PORT);
268
269 /* Lock the SuperIO chip */
270 outb_p(LOCK_DATA, IO_INDEX_PORT);
271
272 spin_unlock_irqrestore(&spinlock, flags);
273
274 *status = 0;
275 if (new_status & 1)
276 *status |= WDIOF_CARDRESET;
277
278 return 0;
279}
280
281
282/*
283 * /dev/watchdog handling
284 */
285
286static int wdt_open(struct inode *inode, struct file *file)
287{
288 /* If the watchdog is alive we don't need to start it again */
289 if (test_and_set_bit(0, &timer_alive))
290 return -EBUSY;
291
292 if (nowayout)
293 __module_get(THIS_MODULE);
294
295 wdt_start();
296 return stream_open(inode, file);
297}
298
299static int wdt_release(struct inode *inode, struct file *file)
300{
301 /*
302 * Shut off the timer.
303 * Lock it in if it's a module and we set nowayout
304 */
305 if (expect_close == 42) {
306 wdt_stop();
307 clear_bit(0, &timer_alive);
308 } else {
309 wdt_keepalive();
310 pr_crit("unexpected close, not stopping watchdog!\n");
311 }
312 expect_close = 0;
313 return 0;
314}
315
316/*
317 * wdt_write:
318 * @file: file handle to the watchdog
319 * @buf: buffer to write (unused as data does not matter here
320 * @count: count of bytes
321 * @ppos: pointer to the position to write. No seeks allowed
322 *
323 * A write to a watchdog device is defined as a keepalive signal. Any
324 * write of data will do, as we don't define content meaning.
325 */
326
327static ssize_t wdt_write(struct file *file, const char __user *buf,
328 size_t count, loff_t *ppos)
329{
330 /* See if we got the magic character 'V' and reload the timer */
331 if (count) {
332 if (!nowayout) {
333 size_t ofs;
334
335 /* note: just in case someone wrote the
336 magic character long ago */
337 expect_close = 0;
338
339 /* scan to see whether or not we got the
340 magic character */
341 for (ofs = 0; ofs != count; ofs++) {
342 char c;
343 if (get_user(c, buf + ofs))
344 return -EFAULT;
345 if (c == 'V')
346 expect_close = 42;
347 }
348 }
349
350 /* someone wrote to us, we should restart timer */
351 wdt_keepalive();
352 }
353 return count;
354}
355
356/*
357 * wdt_ioctl:
358 * @inode: inode of the device
359 * @file: file handle to the device
360 * @cmd: watchdog command
361 * @arg: argument pointer
362 *
363 * The watchdog API defines a common set of functions for all watchdogs
364 * according to their available features.
365 */
366
367static const struct watchdog_info ident = {
368 .options = WDIOF_SETTIMEOUT | WDIOF_MAGICCLOSE | WDIOF_KEEPALIVEPING,
369 .firmware_version = 1,
370 .identity = WATCHDOG_NAME,
371};
372
373static long wdt_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
374{
375 int status;
376 int new_options, retval = -EINVAL;
377 int new_timeout;
378 union {
379 struct watchdog_info __user *ident;
380 int __user *i;
381 } uarg;
382
383 uarg.i = (int __user *)arg;
384
385 switch (cmd) {
386 case WDIOC_GETSUPPORT:
387 return copy_to_user(uarg.ident, &ident,
388 sizeof(ident)) ? -EFAULT : 0;
389
390 case WDIOC_GETSTATUS:
391 wdt_get_status(&status);
392 return put_user(status, uarg.i);
393
394 case WDIOC_GETBOOTSTATUS:
395 return put_user(0, uarg.i);
396
397 case WDIOC_SETOPTIONS:
398 if (get_user(new_options, uarg.i))
399 return -EFAULT;
400
401 if (new_options & WDIOS_DISABLECARD) {
402 wdt_stop();
403 retval = 0;
404 }
405
406 if (new_options & WDIOS_ENABLECARD) {
407 wdt_start();
408 retval = 0;
409 }
410
411 return retval;
412
413 case WDIOC_KEEPALIVE:
414 wdt_keepalive();
415 return 0;
416
417 case WDIOC_SETTIMEOUT:
418 if (get_user(new_timeout, uarg.i))
419 return -EFAULT;
420
421 if (wdt_set_timeout(new_timeout))
422 return -EINVAL;
423
424 wdt_keepalive();
425 fallthrough;
426
427 case WDIOC_GETTIMEOUT:
428 return put_user(timeout, uarg.i);
429
430 default:
431 return -ENOTTY;
432
433 }
434}
435
436static int wdt_notify_sys(struct notifier_block *this, unsigned long code,
437 void *unused)
438{
439 if (code == SYS_DOWN || code == SYS_HALT)
440 wdt_stop();
441 return NOTIFY_DONE;
442}
443
444static const struct file_operations wdt_fops = {
445 .owner = THIS_MODULE,
446 .llseek = no_llseek,
447 .write = wdt_write,
448 .unlocked_ioctl = wdt_ioctl,
449 .compat_ioctl = compat_ptr_ioctl,
450 .open = wdt_open,
451 .release = wdt_release,
452};
453
454static struct miscdevice wdt_miscdev = {
455 .minor = WATCHDOG_MINOR,
456 .name = "watchdog",
457 .fops = &wdt_fops,
458};
459
460static struct notifier_block wdt_notifier = {
461 .notifier_call = wdt_notify_sys,
462};
463
464static int __init w83977f_wdt_init(void)
465{
466 int rc;
467
468 pr_info("driver v%s\n", WATCHDOG_VERSION);
469
470 /*
471 * Check that the timeout value is within it's range;
472 * if not reset to the default
473 */
474 if (wdt_set_timeout(timeout)) {
475 wdt_set_timeout(DEFAULT_TIMEOUT);
476 pr_info("timeout value must be 15 <= timeout <= 7635, using %d\n",
477 DEFAULT_TIMEOUT);
478 }
479
480 if (!request_region(IO_INDEX_PORT, 2, WATCHDOG_NAME)) {
481 pr_err("I/O address 0x%04x already in use\n", IO_INDEX_PORT);
482 rc = -EIO;
483 goto err_out;
484 }
485
486 rc = register_reboot_notifier(&wdt_notifier);
487 if (rc) {
488 pr_err("cannot register reboot notifier (err=%d)\n", rc);
489 goto err_out_region;
490 }
491
492 rc = misc_register(&wdt_miscdev);
493 if (rc) {
494 pr_err("cannot register miscdev on minor=%d (err=%d)\n",
495 wdt_miscdev.minor, rc);
496 goto err_out_reboot;
497 }
498
499 pr_info("initialized. timeout=%d sec (nowayout=%d testmode=%d)\n",
500 timeout, nowayout, testmode);
501
502 return 0;
503
504err_out_reboot:
505 unregister_reboot_notifier(&wdt_notifier);
506err_out_region:
507 release_region(IO_INDEX_PORT, 2);
508err_out:
509 return rc;
510}
511
512static void __exit w83977f_wdt_exit(void)
513{
514 wdt_stop();
515 misc_deregister(&wdt_miscdev);
516 unregister_reboot_notifier(&wdt_notifier);
517 release_region(IO_INDEX_PORT, 2);
518}
519
520module_init(w83977f_wdt_init);
521module_exit(w83977f_wdt_exit);
522
523MODULE_AUTHOR("Jose Goncalves <jose.goncalves@inov.pt>");
524MODULE_DESCRIPTION("Driver for watchdog timer in W83977F I/O chip");
525MODULE_LICENSE("GPL");
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);