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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
47
48static unsigned long wdt_is_open;
49static char expect_close;
50static DEFINE_SPINLOCK(io_lock);
51
52
53static int wdt_io = 0x2e;
54module_param(wdt_io, int, 0);
55MODULE_PARM_DESC(wdt_io, "w83697hf/hg WDT io port (default 0x2e, 0 = autodetect)");
56
57static int timeout = WATCHDOG_TIMEOUT;
58module_param(timeout, int, 0);
59MODULE_PARM_DESC(timeout, "Watchdog timeout in seconds. 1<= timeout <=255, default=" __MODULE_STRING(WATCHDOG_TIMEOUT) ".");
60
61static int nowayout = WATCHDOG_NOWAYOUT;
62module_param(nowayout, int, 0);
63MODULE_PARM_DESC(nowayout, "Watchdog cannot be stopped once started (default=" __MODULE_STRING(WATCHDOG_NOWAYOUT) ")");
64
65
66
67
68
69#define W83697HF_EFER (wdt_io+0)
70#define W83697HF_EFIR (wdt_io+0)
71#define W83697HF_EFDR (wdt_io+1)
72
73static inline void
74w83697hf_unlock(void)
75{
76 outb_p(0x87, W83697HF_EFER);
77 outb_p(0x87, W83697HF_EFER);
78}
79
80static inline void
81w83697hf_lock(void)
82{
83 outb_p(0xAA, W83697HF_EFER);
84}
85
86
87
88
89
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
105static void
106w83697hf_write_timeout(int timeout)
107{
108 w83697hf_set_reg(0xF4, timeout);
109}
110
111static void
112w83697hf_select_wdt(void)
113{
114 w83697hf_unlock();
115 w83697hf_set_reg(0x07, 0x08);
116}
117
118static inline void
119w83697hf_deselect_wdt(void)
120{
121 w83697hf_lock();
122}
123
124static void
125w83697hf_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);
135
136 bbuf = w83697hf_get_reg(0xF3);
137 bbuf &= ~0x04;
138 w83697hf_set_reg(0xF3, bbuf);
139
140 w83697hf_deselect_wdt();
141}
142
143static int
144wdt_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
156static int
157wdt_enable(void)
158{
159 spin_lock(&io_lock);
160 w83697hf_select_wdt();
161
162 w83697hf_write_timeout(timeout);
163 w83697hf_set_reg(0x30, 1);
164
165 w83697hf_deselect_wdt();
166 spin_unlock(&io_lock);
167 return 0;
168}
169
170static int
171wdt_disable(void)
172{
173 spin_lock(&io_lock);
174 w83697hf_select_wdt();
175
176 w83697hf_set_reg(0x30, 0);
177 w83697hf_write_timeout(0);
178
179 w83697hf_deselect_wdt();
180 spin_unlock(&io_lock);
181 return 0;
182}
183
184static int
185wdt_set_heartbeat(int t)
186{
187 if ((t < 1) || (t > 255))
188 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:
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
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
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
287
288
289 wdt_enable();
290 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 {
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
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
317 wdt_disable();
318 }
319 return NOTIFY_DONE;
320}
321
322
323
324
325
326static 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
335static struct miscdevice wdt_miscdev = {
336 .minor = WATCHDOG_MINOR,
337 .name = "watchdog",
338 .fops = &wdt_fops,
339};
340
341
342
343
344
345
346static struct notifier_block wdt_notifier = {
347 .notifier_call = wdt_notify_sys,
348};
349
350static 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();
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
372static int w83697hf_ioports[] = { 0x2e, 0x4e, 0x00 };
373
374static int __init
375wdt_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
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();
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
425out:
426 return ret;
427unreg_reboot:
428 unregister_reboot_notifier(&wdt_notifier);
429unreg_regions:
430 release_region(wdt_io, 2);
431 goto out;
432}
433
434static void __exit
435wdt_exit(void)
436{
437 misc_deregister(&wdt_miscdev);
438 unregister_reboot_notifier(&wdt_notifier);
439 release_region(wdt_io, 2);
440}
441
442module_init(wdt_init);
443module_exit(wdt_exit);
444
445MODULE_LICENSE("GPL");
446MODULE_AUTHOR("Marcus Junker <junker@anduras.de>, Samuel Tardieu <sam@rfc1149.net>");
447MODULE_DESCRIPTION("w83697hf/hg WDT driver");
448MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR);
449
