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Marcus Junkerf9a8c892006-08-24 17:11:50 +02001/*
Samuel Tardieude710d62006-09-07 11:57:00 +02002 * w83697hf/hg WDT driver
Marcus Junkerf9a8c892006-08-24 17:11:50 +02003 *
Samuel Tardieu3fdee8d2006-09-07 11:57:00 +02004 * (c) Copyright 2006 Samuel Tardieu <sam@rfc1149.net>
Marcus Junkerf9a8c892006-08-24 17:11:50 +02005 * (c) Copyright 2006 Marcus Junker <junker@anduras.de>
6 *
Samuel Tardieude710d62006-09-07 11:57:00 +02007 * Based on w83627hf_wdt.c which is based on advantechwdt.c
8 * which is based on wdt.c.
Marcus Junkerf9a8c892006-08-24 17:11:50 +02009 * Original copyright messages:
10 *
Jan Engelhardt96de0e22007-10-19 23:21:04 +020011 * (c) Copyright 2003 Pádraig Brady <P@draigBrady.com>
Marcus Junkerf9a8c892006-08-24 17:11:50 +020012 *
13 * (c) Copyright 2000-2001 Marek Michalkiewicz <marekm@linux.org.pl>
14 *
15 * (c) Copyright 1996 Alan Cox <alan@redhat.com>, All Rights Reserved.
16 * http://www.redhat.com
17 *
18 * This program is free software; you can redistribute it and/or
19 * modify it under the terms of the GNU General Public License
20 * as published by the Free Software Foundation; either version
21 * 2 of the License, or (at your option) any later version.
22 *
23 * Neither Marcus Junker nor ANDURAS AG admit liability nor provide
24 * warranty for any of this software. This material is provided
25 * "AS-IS" and at no charge.
26 */
27
28#include <linux/module.h>
29#include <linux/moduleparam.h>
30#include <linux/types.h>
31#include <linux/miscdevice.h>
32#include <linux/watchdog.h>
33#include <linux/fs.h>
34#include <linux/ioport.h>
35#include <linux/notifier.h>
36#include <linux/reboot.h>
37#include <linux/init.h>
Wim Van Sebroeckab9d4412006-09-02 18:50:20 +020038#include <linux/spinlock.h>
Marcus Junkerf9a8c892006-08-24 17:11:50 +020039
40#include <asm/io.h>
41#include <asm/uaccess.h>
42#include <asm/system.h>
43
Samuel Tardieude710d62006-09-07 11:57:00 +020044#define WATCHDOG_NAME "w83697hf/hg WDT"
Marcus Junkerf9a8c892006-08-24 17:11:50 +020045#define PFX WATCHDOG_NAME ": "
46#define WATCHDOG_TIMEOUT 60 /* 60 sec default timeout */
47
48static unsigned long wdt_is_open;
49static char expect_close;
Alexey Dobriyanc7dfd0c2007-11-01 16:27:08 -070050static DEFINE_SPINLOCK(io_lock);
Marcus Junkerf9a8c892006-08-24 17:11:50 +020051
52/* You must set this - there is no sane way to probe for this board. */
Samuel Tardieuc81b2992006-09-07 11:57:00 +020053static int wdt_io = 0x2e;
Marcus Junkerf9a8c892006-08-24 17:11:50 +020054module_param(wdt_io, int, 0);
Samuel Tardieuc81b2992006-09-07 11:57:00 +020055MODULE_PARM_DESC(wdt_io, "w83697hf/hg WDT io port (default 0x2e, 0 = autodetect)");
Marcus Junkerf9a8c892006-08-24 17:11:50 +020056
57static int timeout = WATCHDOG_TIMEOUT; /* in seconds */
58module_param(timeout, int, 0);
Samuel Tardieueb644192006-09-07 11:57:00 +020059MODULE_PARM_DESC(timeout, "Watchdog timeout in seconds. 1<= timeout <=255, default=" __MODULE_STRING(WATCHDOG_TIMEOUT) ".");
Marcus Junkerf9a8c892006-08-24 17:11:50 +020060
61static int nowayout = WATCHDOG_NOWAYOUT;
62module_param(nowayout, int, 0);
Wim Van Sebroeckbffda5c2007-01-27 20:54:24 +010063MODULE_PARM_DESC(nowayout, "Watchdog cannot be stopped once started (default=" __MODULE_STRING(WATCHDOG_NOWAYOUT) ")");
Marcus Junkerf9a8c892006-08-24 17:11:50 +020064
65/*
66 * Kernel methods.
67 */
68
Samuel Tardieu44d7d322006-09-07 11:57:00 +020069#define W83697HF_EFER (wdt_io+0) /* Extended Function Enable Register */
70#define W83697HF_EFIR (wdt_io+0) /* Extended Function Index Register (same as EFER) */
71#define W83697HF_EFDR (wdt_io+1) /* Extended Function Data Register */
Marcus Junkerf9a8c892006-08-24 17:11:50 +020072
Samuel Tardieuf7be3322006-09-07 11:57:00 +020073static inline void
74w83697hf_unlock(void)
Marcus Junkerf9a8c892006-08-24 17:11:50 +020075{
Samuel Tardieu44d7d322006-09-07 11:57:00 +020076 outb_p(0x87, W83697HF_EFER); /* Enter extended function mode */
77 outb_p(0x87, W83697HF_EFER); /* Again according to manual */
Samuel Tardieuf7be3322006-09-07 11:57:00 +020078}
79
Samuel Tardieufe851eb2006-09-07 11:57:00 +020080static inline void
81w83697hf_lock(void)
82{
83 outb_p(0xAA, W83697HF_EFER); /* Leave extended function mode */
84}
85
Samuel Tardieu0cd54472006-09-07 11:57:00 +020086/*
Samuel Tardieud46ab592006-09-07 11:57:00 +020087 * The three functions w83697hf_get_reg(), w83697hf_set_reg() and
88 * w83697hf_write_timeout() must be called with the device unlocked.
Samuel Tardieu0cd54472006-09-07 11:57:00 +020089 */
90
91static unsigned char
92w83697hf_get_reg(unsigned char reg)
93{
94 outb_p(reg, W83697HF_EFIR);
95 return inb_p(W83697HF_EFDR);
96}
97
98static void
99w83697hf_set_reg(unsigned char reg, unsigned char data)
100{
101 outb_p(reg, W83697HF_EFIR);
102 outb_p(data, W83697HF_EFDR);
103}
104
Samuel Tardieuf7be3322006-09-07 11:57:00 +0200105static void
Samuel Tardieud46ab592006-09-07 11:57:00 +0200106w83697hf_write_timeout(int timeout)
107{
108 w83697hf_set_reg(0xF4, timeout); /* Write Timeout counter to CRF4 */
109}
110
111static void
Samuel Tardieua7933e02006-09-07 11:57:00 +0200112w83697hf_select_wdt(void)
113{
114 w83697hf_unlock();
115 w83697hf_set_reg(0x07, 0x08); /* Switch to logic device 8 (GPIO2) */
116}
117
118static inline void
119w83697hf_deselect_wdt(void)
120{
121 w83697hf_lock();
122}
123
124static void
Marcus Junkerf9a8c892006-08-24 17:11:50 +0200125w83697hf_init(void)
126{
Samuel Tardieub7b98682006-09-07 11:57:00 +0200127 unsigned char bbuf;
Marcus Junkerf9a8c892006-08-24 17:11:50 +0200128
Samuel Tardieufa69afd2006-09-07 11:57:00 +0200129 w83697hf_select_wdt();
130
Samuel Tardieub7b98682006-09-07 11:57:00 +0200131 bbuf = w83697hf_get_reg(0x29);
132 bbuf &= ~0x60;
133 bbuf |= 0x20;
134 w83697hf_set_reg(0x29, bbuf); /* Set pin 119 to WDTO# mode (= CR29, WDT0) */
Marcus Junkerf9a8c892006-08-24 17:11:50 +0200135
Samuel Tardieub7b98682006-09-07 11:57:00 +0200136 bbuf = w83697hf_get_reg(0xF3);
137 bbuf &= ~0x04;
138 w83697hf_set_reg(0xF3, bbuf); /* Count mode is seconds */
Marcus Junkerf9a8c892006-08-24 17:11:50 +0200139
Samuel Tardieufa69afd2006-09-07 11:57:00 +0200140 w83697hf_deselect_wdt();
Marcus Junkerf9a8c892006-08-24 17:11:50 +0200141}
142
Samuel Tardieu089d8132006-09-07 11:57:00 +0200143static int
144wdt_ping(void)
Marcus Junkerf9a8c892006-08-24 17:11:50 +0200145{
Wim Van Sebroeckab9d4412006-09-02 18:50:20 +0200146 spin_lock(&io_lock);
Samuel Tardieua7933e02006-09-07 11:57:00 +0200147 w83697hf_select_wdt();
Marcus Junkerf9a8c892006-08-24 17:11:50 +0200148
Samuel Tardieud46ab592006-09-07 11:57:00 +0200149 w83697hf_write_timeout(timeout);
Marcus Junkerf9a8c892006-08-24 17:11:50 +0200150
Samuel Tardieua7933e02006-09-07 11:57:00 +0200151 w83697hf_deselect_wdt();
Wim Van Sebroeckab9d4412006-09-02 18:50:20 +0200152 spin_unlock(&io_lock);
Samuel Tardieu089d8132006-09-07 11:57:00 +0200153 return 0;
Marcus Junkerf9a8c892006-08-24 17:11:50 +0200154}
155
156static int
Samuel Tardieu089d8132006-09-07 11:57:00 +0200157wdt_enable(void)
Marcus Junkerf9a8c892006-08-24 17:11:50 +0200158{
Samuel Tardieu089d8132006-09-07 11:57:00 +0200159 spin_lock(&io_lock);
160 w83697hf_select_wdt();
161
162 w83697hf_write_timeout(timeout);
163 w83697hf_set_reg(0x30, 1); /* Enable timer */
164
165 w83697hf_deselect_wdt();
166 spin_unlock(&io_lock);
Marcus Junkerf9a8c892006-08-24 17:11:50 +0200167 return 0;
168}
169
170static int
171wdt_disable(void)
172{
Samuel Tardieu089d8132006-09-07 11:57:00 +0200173 spin_lock(&io_lock);
174 w83697hf_select_wdt();
175
176 w83697hf_set_reg(0x30, 0); /* Disable timer */
177 w83697hf_write_timeout(0);
178
179 w83697hf_deselect_wdt();
180 spin_unlock(&io_lock);
Marcus Junkerf9a8c892006-08-24 17:11:50 +0200181 return 0;
182}
183
184static int
185wdt_set_heartbeat(int t)
186{
Samuel Tardieueb644192006-09-07 11:57:00 +0200187 if ((t < 1) || (t > 255))
Marcus Junkerf9a8c892006-08-24 17:11:50 +0200188 return -EINVAL;
189
190 timeout = t;
191 return 0;
192}
193
194static ssize_t
195wdt_write(struct file *file, const char __user *buf, size_t count, loff_t *ppos)
196{
197 if (count) {
198 if (!nowayout) {
199 size_t i;
200
201 expect_close = 0;
202
203 for (i = 0; i != count; i++) {
204 char c;
205 if (get_user(c, buf+i))
206 return -EFAULT;
207 if (c == 'V')
208 expect_close = 42;
209 }
210 }
211 wdt_ping();
212 }
213 return count;
214}
215
216static int
217wdt_ioctl(struct inode *inode, struct file *file, unsigned int cmd,
218 unsigned long arg)
219{
220 void __user *argp = (void __user *)arg;
221 int __user *p = argp;
222 int new_timeout;
223 static struct watchdog_info ident = {
224 .options = WDIOF_KEEPALIVEPING | WDIOF_SETTIMEOUT | WDIOF_MAGICCLOSE,
225 .firmware_version = 1,
226 .identity = "W83697HF WDT",
227 };
228
229 switch (cmd) {
230 case WDIOC_GETSUPPORT:
Samuel Tardieudb165252006-09-07 11:57:00 +0200231 if (copy_to_user(argp, &ident, sizeof(ident)))
232 return -EFAULT;
233 break;
Marcus Junkerf9a8c892006-08-24 17:11:50 +0200234
235 case WDIOC_GETSTATUS:
236 case WDIOC_GETBOOTSTATUS:
Samuel Tardieudb165252006-09-07 11:57:00 +0200237 return put_user(0, p);
Marcus Junkerf9a8c892006-08-24 17:11:50 +0200238
239 case WDIOC_KEEPALIVE:
Samuel Tardieudb165252006-09-07 11:57:00 +0200240 wdt_ping();
241 break;
Marcus Junkerf9a8c892006-08-24 17:11:50 +0200242
243 case WDIOC_SETTIMEOUT:
Samuel Tardieudb165252006-09-07 11:57:00 +0200244 if (get_user(new_timeout, p))
245 return -EFAULT;
246 if (wdt_set_heartbeat(new_timeout))
247 return -EINVAL;
248 wdt_ping();
249 /* Fall */
Marcus Junkerf9a8c892006-08-24 17:11:50 +0200250
251 case WDIOC_GETTIMEOUT:
Samuel Tardieudb165252006-09-07 11:57:00 +0200252 return put_user(timeout, p);
Marcus Junkerf9a8c892006-08-24 17:11:50 +0200253
254 case WDIOC_SETOPTIONS:
255 {
Samuel Tardieudb165252006-09-07 11:57:00 +0200256 int options, retval = -EINVAL;
Marcus Junkerf9a8c892006-08-24 17:11:50 +0200257
Samuel Tardieudb165252006-09-07 11:57:00 +0200258 if (get_user(options, p))
259 return -EFAULT;
Marcus Junkerf9a8c892006-08-24 17:11:50 +0200260
Samuel Tardieudb165252006-09-07 11:57:00 +0200261 if (options & WDIOS_DISABLECARD) {
262 wdt_disable();
263 retval = 0;
264 }
Marcus Junkerf9a8c892006-08-24 17:11:50 +0200265
Samuel Tardieudb165252006-09-07 11:57:00 +0200266 if (options & WDIOS_ENABLECARD) {
Samuel Tardieu089d8132006-09-07 11:57:00 +0200267 wdt_enable();
Samuel Tardieudb165252006-09-07 11:57:00 +0200268 retval = 0;
269 }
Marcus Junkerf9a8c892006-08-24 17:11:50 +0200270
Samuel Tardieudb165252006-09-07 11:57:00 +0200271 return retval;
Marcus Junkerf9a8c892006-08-24 17:11:50 +0200272 }
273
274 default:
Samuel Tardieudb165252006-09-07 11:57:00 +0200275 return -ENOTTY;
Marcus Junkerf9a8c892006-08-24 17:11:50 +0200276 }
277 return 0;
278}
279
280static int
281wdt_open(struct inode *inode, struct file *file)
282{
283 if (test_and_set_bit(0, &wdt_is_open))
284 return -EBUSY;
285 /*
286 * Activate
287 */
288
Samuel Tardieu089d8132006-09-07 11:57:00 +0200289 wdt_enable();
Marcus Junkerf9a8c892006-08-24 17:11:50 +0200290 return nonseekable_open(inode, file);
291}
292
293static int
294wdt_close(struct inode *inode, struct file *file)
295{
296 if (expect_close == 42) {
297 wdt_disable();
298 } else {
Samuel Tardieudb165252006-09-07 11:57:00 +0200299 printk (KERN_CRIT PFX "Unexpected close, not stopping watchdog!\n");
Marcus Junkerf9a8c892006-08-24 17:11:50 +0200300 wdt_ping();
301 }
302 expect_close = 0;
303 clear_bit(0, &wdt_is_open);
304 return 0;
305}
306
307/*
308 * Notifier for system down
309 */
310
311static int
312wdt_notify_sys(struct notifier_block *this, unsigned long code,
313 void *unused)
314{
315 if (code == SYS_DOWN || code == SYS_HALT) {
316 /* Turn the WDT off */
317 wdt_disable();
318 }
319 return NOTIFY_DONE;
320}
321
322/*
323 * Kernel Interfaces
324 */
325
Arjan van de Ven2b8693c2007-02-12 00:55:32 -0800326static const struct file_operations wdt_fops = {
Marcus Junkerf9a8c892006-08-24 17:11:50 +0200327 .owner = THIS_MODULE,
328 .llseek = no_llseek,
329 .write = wdt_write,
330 .ioctl = wdt_ioctl,
331 .open = wdt_open,
332 .release = wdt_close,
333};
334
335static struct miscdevice wdt_miscdev = {
336 .minor = WATCHDOG_MINOR,
337 .name = "watchdog",
338 .fops = &wdt_fops,
339};
340
341/*
342 * The WDT needs to learn about soft shutdowns in order to
343 * turn the timebomb registers off.
344 */
345
346static struct notifier_block wdt_notifier = {
347 .notifier_call = wdt_notify_sys,
348};
349
Samuel Tardieuc81b2992006-09-07 11:57:00 +0200350static int
351w83697hf_check_wdt(void)
352{
353 if (!request_region(wdt_io, 2, WATCHDOG_NAME)) {
354 printk (KERN_ERR PFX "I/O address 0x%x already in use\n", wdt_io);
355 return -EIO;
356 }
357
358 printk (KERN_DEBUG PFX "Looking for watchdog at address 0x%x\n", wdt_io);
359 w83697hf_unlock();
360 if (w83697hf_get_reg(0x20) == 0x60) {
361 printk (KERN_INFO PFX "watchdog found at address 0x%x\n", wdt_io);
362 w83697hf_lock();
363 return 0;
364 }
365 w83697hf_lock(); /* Reprotect in case it was a compatible device */
366
367 printk (KERN_INFO PFX "watchdog not found at address 0x%x\n", wdt_io);
368 release_region(wdt_io, 2);
369 return -EIO;
370}
371
Wim Van Sebroecke223f012006-09-15 17:59:07 +0200372static int w83697hf_ioports[] = { 0x2e, 0x4e, 0x00 };
373
Marcus Junkerf9a8c892006-08-24 17:11:50 +0200374static int __init
375wdt_init(void)
376{
Wim Van Sebroecke223f012006-09-15 17:59:07 +0200377 int ret, i, found = 0;
Marcus Junkerf9a8c892006-08-24 17:11:50 +0200378
Samuel Tardieude710d62006-09-07 11:57:00 +0200379 printk (KERN_INFO PFX "WDT driver for W83697HF/HG initializing\n");
Marcus Junkerf9a8c892006-08-24 17:11:50 +0200380
Wim Van Sebroecke223f012006-09-15 17:59:07 +0200381 if (wdt_io == 0) {
382 /* we will autodetect the W83697HF/HG watchdog */
383 for (i = 0; ((!found) && (w83697hf_ioports[i] != 0)); i++) {
384 wdt_io = w83697hf_ioports[i];
Wim Van Sebroeckcde10ba2008-01-18 21:01:34 +0000385 if (!w83697hf_check_wdt())
Wim Van Sebroecke223f012006-09-15 17:59:07 +0200386 found++;
387 }
388 } else {
Samuel Tardieuc81b2992006-09-07 11:57:00 +0200389 if (!w83697hf_check_wdt())
Wim Van Sebroecke223f012006-09-15 17:59:07 +0200390 found++;
Samuel Tardieuc81b2992006-09-07 11:57:00 +0200391 }
392
Wim Van Sebroecke223f012006-09-15 17:59:07 +0200393 if (!found) {
394 printk (KERN_ERR PFX "No W83697HF/HG could be found\n");
395 ret = -EIO;
396 goto out;
397 }
Samuel Tardieuc81b2992006-09-07 11:57:00 +0200398
Samuel Tardieufa69afd2006-09-07 11:57:00 +0200399 w83697hf_init();
400 wdt_disable(); /* Disable watchdog until first use */
Samuel Tardieuc81b2992006-09-07 11:57:00 +0200401
Marcus Junkerf9a8c892006-08-24 17:11:50 +0200402 if (wdt_set_heartbeat(timeout)) {
403 wdt_set_heartbeat(WATCHDOG_TIMEOUT);
Samuel Tardieueb644192006-09-07 11:57:00 +0200404 printk (KERN_INFO PFX "timeout value must be 1<=timeout<=255, using %d\n",
Marcus Junkerf9a8c892006-08-24 17:11:50 +0200405 WATCHDOG_TIMEOUT);
406 }
407
Marcus Junkerf9a8c892006-08-24 17:11:50 +0200408 ret = register_reboot_notifier(&wdt_notifier);
409 if (ret != 0) {
410 printk (KERN_ERR PFX "cannot register reboot notifier (err=%d)\n",
411 ret);
412 goto unreg_regions;
413 }
414
415 ret = misc_register(&wdt_miscdev);
416 if (ret != 0) {
417 printk (KERN_ERR PFX "cannot register miscdev on minor=%d (err=%d)\n",
418 WATCHDOG_MINOR, ret);
419 goto unreg_reboot;
420 }
421
422 printk (KERN_INFO PFX "initialized. timeout=%d sec (nowayout=%d)\n",
423 timeout, nowayout);
424
425out:
426 return ret;
427unreg_reboot:
428 unregister_reboot_notifier(&wdt_notifier);
429unreg_regions:
Samuel Tardieub41a9f52006-09-07 11:57:00 +0200430 release_region(wdt_io, 2);
Marcus Junkerf9a8c892006-08-24 17:11:50 +0200431 goto out;
432}
433
434static void __exit
435wdt_exit(void)
436{
437 misc_deregister(&wdt_miscdev);
438 unregister_reboot_notifier(&wdt_notifier);
Samuel Tardieub41a9f52006-09-07 11:57:00 +0200439 release_region(wdt_io, 2);
Marcus Junkerf9a8c892006-08-24 17:11:50 +0200440}
441
442module_init(wdt_init);
443module_exit(wdt_exit);
444
445MODULE_LICENSE("GPL");
Samuel Tardieu3fdee8d2006-09-07 11:57:00 +0200446MODULE_AUTHOR("Marcus Junker <junker@anduras.de>, Samuel Tardieu <sam@rfc1149.net>");
Samuel Tardieude710d62006-09-07 11:57:00 +0200447MODULE_DESCRIPTION("w83697hf/hg WDT driver");
Marcus Junkerf9a8c892006-08-24 17:11:50 +0200448MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR);