1 /*
2 * w83697hf/hg WDT driver
3 *
4 * (c) Copyright 2006 Samuel Tardieu <sam@rfc1149.net>
5 * (c) Copyright 2006 Marcus Junker <junker@anduras.de>
6 *
7 * Based on w83627hf_wdt.c which is based on advantechwdt.c
8 * which is based on wdt.c.
9 * Original copyright messages:
10 *
11 * (c) Copyright 2003 Pádraig Brady <P@draigBrady.com>
12 *
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>
38 #include <linux/spinlock.h>
39
40 #include <asm/io.h>
41 #include <asm/uaccess.h>
42 #include <asm/system.h>
43
44 #define WATCHDOG_NAME "w83697hf/hg WDT"
45 #define PFX WATCHDOG_NAME ": "
46 #define WATCHDOG_TIMEOUT 60 /* 60 sec default timeout */
47
48 static unsigned long wdt_is_open;
49 static char expect_close;
50 static DEFINE_SPINLOCK(io_lock);
51
52 /* You must set this - there is no sane way to probe for this board. */
53 static int wdt_io = 0x2e;
54 module_param(wdt_io, int, 0);
55 MODULE_PARM_DESC(wdt_io, "w83697hf/hg WDT io port (default 0x2e, 0 = autodetect)");
56
57 static int timeout = WATCHDOG_TIMEOUT; /* in seconds */
58 module_param(timeout, int, 0);
59 MODULE_PARM_DESC(timeout, "Watchdog timeout in seconds. 1<= timeout <=255, default=" __MODULE_STRING(WATCHDOG_TIMEOUT) ".");
60
61 static int nowayout = WATCHDOG_NOWAYOUT;
62 module_param(nowayout, int, 0);
63 MODULE_PARM_DESC(nowayout, "Watchdog cannot be stopped once started (default=" __MODULE_STRING(WATCHDOG_NOWAYOUT) ")");
64
65 /*
66 * Kernel methods.
67 */
68
69 #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 */
72
73 static inline void
74 w83697hf_unlock(void)
75 {
76 outb_p(0x87, W83697HF_EFER); /* Enter extended function mode */
77 outb_p(0x87, W83697HF_EFER); /* Again according to manual */
78 }
79
80 static inline void
81 w83697hf_lock(void)
82 {
83 outb_p(0xAA, W83697HF_EFER); /* Leave extended function mode */
84 }
85
86 /*
87 * The three functions w83697hf_get_reg(), w83697hf_set_reg() and
88 * w83697hf_write_timeout() must be called with the device unlocked.
89 */
90
91 static unsigned char
92 w83697hf_get_reg(unsigned char reg)
93 {
94 outb_p(reg, W83697HF_EFIR);
95 return inb_p(W83697HF_EFDR);
96 }
97
98 static void
99 w83697hf_set_reg(unsigned char reg, unsigned char data)
100 {
101 outb_p(reg, W83697HF_EFIR);
102 outb_p(data, W83697HF_EFDR);
103 }
104
105 static void
106 w83697hf_write_timeout(int timeout)
107 {
108 w83697hf_set_reg(0xF4, timeout); /* Write Timeout counter to CRF4 */
109 }
110
111 static void
112 w83697hf_select_wdt(void)
113 {
114 w83697hf_unlock();
115 w83697hf_set_reg(0x07, 0x08); /* Switch to logic device 8 (GPIO2) */
116 }
117
118 static inline void
119 w83697hf_deselect_wdt(void)
120 {
121 w83697hf_lock();
122 }
123
124 static void
125 w83697hf_init(void)
126 {
127 unsigned char bbuf;
128
129 w83697hf_select_wdt();
130
131 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) */
135
136 bbuf = w83697hf_get_reg(0xF3);
137 bbuf &= ~0x04;
138 w83697hf_set_reg(0xF3, bbuf); /* Count mode is seconds */
139
140 w83697hf_deselect_wdt();
141 }
142
143 static int
144 wdt_ping(void)
145 {
146 spin_lock(&io_lock);
147 w83697hf_select_wdt();
148
149 w83697hf_write_timeout(timeout);
150
151 w83697hf_deselect_wdt();
152 spin_unlock(&io_lock);
153 return 0;
154 }
155
156 static int
157 wdt_enable(void)
158 {
159 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);
167 return 0;
168 }
169
170 static int
171 wdt_disable(void)
172 {
173 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);
181 return 0;
182 }
183
184 static int
185 wdt_set_heartbeat(int t)
186 {
187 if ((t < 1) || (t > 255))
188 return -EINVAL;
189
190 timeout = t;
191 return 0;
192 }
193
194 static ssize_t
195 wdt_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
216 static int
217 wdt_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:
231 if (copy_to_user(argp, &ident, sizeof(ident)))
232 return -EFAULT;
233 break;
234
235 case WDIOC_GETSTATUS:
236 case WDIOC_GETBOOTSTATUS:
237 return put_user(0, p);
238
239 case WDIOC_KEEPALIVE:
240 wdt_ping();
241 break;
242
243 case WDIOC_SETTIMEOUT:
244 if (get_user(new_timeout, p))
245 return -EFAULT;
246 if (wdt_set_heartbeat(new_timeout))
247 return -EINVAL;
248 wdt_ping();
249 /* Fall */
250
251 case WDIOC_GETTIMEOUT:
252 return put_user(timeout, p);
253
254 case WDIOC_SETOPTIONS:
255 {
256 int options, retval = -EINVAL;
257
258 if (get_user(options, p))
259 return -EFAULT;
260
261 if (options & WDIOS_DISABLECARD) {
262 wdt_disable();
263 retval = 0;
264 }
265
266 if (options & WDIOS_ENABLECARD) {
267 wdt_enable();
268 retval = 0;
269 }
270
271 return retval;
272 }
273
274 default:
275 return -ENOTTY;
276 }
277 return 0;
278 }
279
280 static int
281 wdt_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
289 wdt_enable();
290 return nonseekable_open(inode, file);
291 }
292
293 static int
294 wdt_close(struct inode *inode, struct file *file)
295 {
296 if (expect_close == 42) {
297 wdt_disable();
298 } else {
299 printk (KERN_CRIT PFX "Unexpected close, not stopping watchdog!\n");
300 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
311 static int
312 wdt_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
326 static const struct file_operations wdt_fops = {
327 .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
335 static 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
346 static struct notifier_block wdt_notifier = {
347 .notifier_call = wdt_notify_sys,
348 };
349
350 static int
351 w83697hf_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
372 static int w83697hf_ioports[] = { 0x2e, 0x4e, 0x00 };
373
374 static int __init
375 wdt_init(void)
376 {
377 int ret, i, found = 0;
378
379 printk (KERN_INFO PFX "WDT driver for W83697HF/HG initializing\n");
380
381 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];
385 if (!w83697hf_check_wdt())
386 found++;
387 }
388 } else {
389 if (!w83697hf_check_wdt())
390 found++;
391 }
392
393 if (!found) {
394 printk (KERN_ERR PFX "No W83697HF/HG could be found\n");
395 ret = -EIO;
396 goto out;
397 }
398
399 w83697hf_init();
400 wdt_disable(); /* Disable watchdog until first use */
401
402 if (wdt_set_heartbeat(timeout)) {
403 wdt_set_heartbeat(WATCHDOG_TIMEOUT);
404 printk (KERN_INFO PFX "timeout value must be 1<=timeout<=255, using %d\n",
405 WATCHDOG_TIMEOUT);
406 }
407
408 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
425 out:
426 return ret;
427 unreg_reboot:
428 unregister_reboot_notifier(&wdt_notifier);
429 unreg_regions:
430 release_region(wdt_io, 2);
431 goto out;
432 }
433
434 static void __exit
435 wdt_exit(void)
436 {
437 misc_deregister(&wdt_miscdev);
438 unregister_reboot_notifier(&wdt_notifier);
439 release_region(wdt_io, 2);
440 }
441
442 module_init(wdt_init);
443 module_exit(wdt_exit);
444
445 MODULE_LICENSE("GPL");
446 MODULE_AUTHOR("Marcus Junker <junker@anduras.de>, Samuel Tardieu <sam@rfc1149.net>");
447 MODULE_DESCRIPTION("w83697hf/hg WDT driver");
448 MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR);
449
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