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1da177e4 LT |
1 | /* |
2 | * Eurotech CPU-1220/1410 on board WDT driver | |
3 | * | |
4 | * (c) Copyright 2001 Ascensit <support@ascensit.com> | |
5 | * (c) Copyright 2001 Rodolfo Giometti <giometti@ascensit.com> | |
6 | * (c) Copyright 2002 Rob Radez <rob@osinvestor.com> | |
7 | * | |
8 | * Based on wdt.c. | |
9 | * Original copyright messages: | |
10 | * | |
11 | * (c) Copyright 1996-1997 Alan Cox <alan@redhat.com>, All Rights Reserved. | |
12 | * http://www.redhat.com | |
13 | * | |
14 | * This program is free software; you can redistribute it and/or | |
15 | * modify it under the terms of the GNU General Public License | |
16 | * as published by the Free Software Foundation; either version | |
17 | * 2 of the License, or (at your option) any later version. | |
18 | * | |
19 | * Neither Alan Cox nor CymruNet Ltd. admit liability nor provide | |
20 | * warranty for any of this software. This material is provided | |
21 | * "AS-IS" and at no charge. | |
22 | * | |
23 | * (c) Copyright 1995 Alan Cox <alan@lxorguk.ukuu.org.uk>* | |
24 | */ | |
25 | ||
26 | /* Changelog: | |
27 | * | |
28 | * 2002/04/25 - Rob Radez | |
29 | * clean up #includes | |
30 | * clean up locking | |
31 | * make __setup param unique | |
32 | * proper options in watchdog_info | |
33 | * add WDIOC_GETSTATUS and WDIOC_SETOPTIONS ioctls | |
34 | * add expect_close support | |
35 | * | |
36 | * 2001 - Rodolfo Giometti | |
37 | * Initial release | |
38 | * | |
39 | * 2002.05.30 - Joel Becker <joel.becker@oracle.com> | |
40 | * Added Matt Domsch's nowayout module option. | |
41 | */ | |
42 | ||
1da177e4 LT |
43 | #include <linux/interrupt.h> |
44 | #include <linux/module.h> | |
45 | #include <linux/moduleparam.h> | |
46 | #include <linux/types.h> | |
47 | #include <linux/miscdevice.h> | |
48 | #include <linux/watchdog.h> | |
49 | #include <linux/fs.h> | |
50 | #include <linux/ioport.h> | |
51 | #include <linux/notifier.h> | |
52 | #include <linux/reboot.h> | |
53 | #include <linux/init.h> | |
54 | ||
55 | #include <asm/io.h> | |
56 | #include <asm/uaccess.h> | |
57 | #include <asm/system.h> | |
58 | ||
59 | static unsigned long eurwdt_is_open; | |
60 | static int eurwdt_timeout; | |
61 | static char eur_expect_close; | |
62 | ||
63 | /* | |
64 | * You must set these - there is no sane way to probe for this board. | |
65 | * You can use eurwdt=x,y to set these now. | |
66 | */ | |
67 | ||
68 | static int io = 0x3f0; | |
69 | static int irq = 10; | |
70 | static char *ev = "int"; | |
71 | ||
72 | #define WDT_TIMEOUT 60 /* 1 minute */ | |
73 | ||
4bfdf378 | 74 | static int nowayout = WATCHDOG_NOWAYOUT; |
1da177e4 | 75 | module_param(nowayout, int, 0); |
bffda5c8 | 76 | MODULE_PARM_DESC(nowayout, "Watchdog cannot be stopped once started (default=" __MODULE_STRING(WATCHDOG_NOWAYOUT) ")"); |
1da177e4 LT |
77 | |
78 | /* | |
79 | * Some symbolic names | |
80 | */ | |
81 | ||
82 | #define WDT_CTRL_REG 0x30 | |
83 | #define WDT_OUTPIN_CFG 0xe2 | |
84 | #define WDT_EVENT_INT 0x00 | |
85 | #define WDT_EVENT_REBOOT 0x08 | |
86 | #define WDT_UNIT_SEL 0xf1 | |
87 | #define WDT_UNIT_SECS 0x80 | |
88 | #define WDT_TIMEOUT_VAL 0xf2 | |
89 | #define WDT_TIMER_CFG 0xf3 | |
90 | ||
91 | ||
92 | module_param(io, int, 0); | |
93 | MODULE_PARM_DESC(io, "Eurotech WDT io port (default=0x3f0)"); | |
94 | module_param(irq, int, 0); | |
95 | MODULE_PARM_DESC(irq, "Eurotech WDT irq (default=10)"); | |
96 | module_param(ev, charp, 0); | |
97 | MODULE_PARM_DESC(ev, "Eurotech WDT event type (default is `int')"); | |
98 | ||
99 | ||
100 | /* | |
101 | * Programming support | |
102 | */ | |
103 | ||
104 | static inline void eurwdt_write_reg(u8 index, u8 data) | |
105 | { | |
106 | outb(index, io); | |
107 | outb(data, io+1); | |
108 | } | |
109 | ||
110 | static inline void eurwdt_lock_chip(void) | |
111 | { | |
112 | outb(0xaa, io); | |
113 | } | |
114 | ||
115 | static inline void eurwdt_unlock_chip(void) | |
116 | { | |
117 | outb(0x55, io); | |
118 | eurwdt_write_reg(0x07, 0x08); /* set the logical device */ | |
119 | } | |
120 | ||
121 | static inline void eurwdt_set_timeout(int timeout) | |
122 | { | |
123 | eurwdt_write_reg(WDT_TIMEOUT_VAL, (u8) timeout); | |
124 | } | |
125 | ||
126 | static inline void eurwdt_disable_timer(void) | |
127 | { | |
128 | eurwdt_set_timeout(0); | |
129 | } | |
130 | ||
131 | static void eurwdt_activate_timer(void) | |
132 | { | |
133 | eurwdt_disable_timer(); | |
134 | eurwdt_write_reg(WDT_CTRL_REG, 0x01); /* activate the WDT */ | |
135 | eurwdt_write_reg(WDT_OUTPIN_CFG, !strcmp("int", ev) ? WDT_EVENT_INT : WDT_EVENT_REBOOT); | |
136 | ||
137 | /* Setting interrupt line */ | |
138 | if (irq == 2 || irq > 15 || irq < 0) { | |
139 | printk(KERN_ERR ": invalid irq number\n"); | |
140 | irq = 0; /* if invalid we disable interrupt */ | |
141 | } | |
142 | if (irq == 0) | |
143 | printk(KERN_INFO ": interrupt disabled\n"); | |
144 | ||
145 | eurwdt_write_reg(WDT_TIMER_CFG, irq<<4); | |
146 | ||
147 | eurwdt_write_reg(WDT_UNIT_SEL, WDT_UNIT_SECS); /* we use seconds */ | |
148 | eurwdt_set_timeout(0); /* the default timeout */ | |
149 | } | |
150 | ||
151 | ||
152 | /* | |
153 | * Kernel methods. | |
154 | */ | |
155 | ||
7d12e780 | 156 | static irqreturn_t eurwdt_interrupt(int irq, void *dev_id) |
1da177e4 LT |
157 | { |
158 | printk(KERN_CRIT "timeout WDT timeout\n"); | |
159 | ||
160 | #ifdef ONLY_TESTING | |
161 | printk(KERN_CRIT "Would Reboot.\n"); | |
162 | #else | |
163 | printk(KERN_CRIT "Initiating system reboot.\n"); | |
cc1d3a9a | 164 | emergency_restart(); |
1da177e4 LT |
165 | #endif |
166 | return IRQ_HANDLED; | |
167 | } | |
168 | ||
169 | ||
170 | /** | |
171 | * eurwdt_ping: | |
172 | * | |
173 | * Reload counter one with the watchdog timeout. | |
174 | */ | |
175 | ||
176 | static void eurwdt_ping(void) | |
177 | { | |
178 | /* Write the watchdog default value */ | |
179 | eurwdt_set_timeout(eurwdt_timeout); | |
180 | } | |
181 | ||
182 | /** | |
183 | * eurwdt_write: | |
184 | * @file: file handle to the watchdog | |
185 | * @buf: buffer to write (unused as data does not matter here | |
186 | * @count: count of bytes | |
187 | * @ppos: pointer to the position to write. No seeks allowed | |
188 | * | |
189 | * A write to a watchdog device is defined as a keepalive signal. Any | |
190 | * write of data will do, as we we don't define content meaning. | |
191 | */ | |
192 | ||
193 | static ssize_t eurwdt_write(struct file *file, const char __user *buf, | |
194 | size_t count, loff_t *ppos) | |
195 | { | |
196 | if (count) { | |
197 | if (!nowayout) { | |
198 | size_t i; | |
199 | ||
200 | eur_expect_close = 0; | |
201 | ||
202 | for (i = 0; i != count; i++) { | |
203 | char c; | |
204 | if(get_user(c, buf+i)) | |
205 | return -EFAULT; | |
206 | if (c == 'V') | |
207 | eur_expect_close = 42; | |
208 | } | |
209 | } | |
210 | eurwdt_ping(); /* the default timeout */ | |
211 | } | |
212 | ||
213 | return count; | |
214 | } | |
215 | ||
216 | /** | |
217 | * eurwdt_ioctl: | |
218 | * @inode: inode of the device | |
219 | * @file: file handle to the device | |
220 | * @cmd: watchdog command | |
221 | * @arg: argument pointer | |
222 | * | |
223 | * The watchdog API defines a common set of functions for all watchdogs | |
224 | * according to their available features. | |
225 | */ | |
226 | ||
227 | static int eurwdt_ioctl(struct inode *inode, struct file *file, | |
228 | unsigned int cmd, unsigned long arg) | |
229 | { | |
230 | void __user *argp = (void __user *)arg; | |
231 | int __user *p = argp; | |
232 | static struct watchdog_info ident = { | |
233 | .options = WDIOF_KEEPALIVEPING | WDIOF_SETTIMEOUT | WDIOF_MAGICCLOSE, | |
234 | .firmware_version = 1, | |
235 | .identity = "WDT Eurotech CPU-1220/1410", | |
236 | }; | |
237 | ||
238 | int time; | |
239 | int options, retval = -EINVAL; | |
240 | ||
241 | switch(cmd) { | |
242 | default: | |
795b89d2 | 243 | return -ENOTTY; |
1da177e4 LT |
244 | |
245 | case WDIOC_GETSUPPORT: | |
246 | return copy_to_user(argp, &ident, sizeof(ident)) ? -EFAULT : 0; | |
247 | ||
248 | case WDIOC_GETSTATUS: | |
249 | case WDIOC_GETBOOTSTATUS: | |
250 | return put_user(0, p); | |
251 | ||
252 | case WDIOC_KEEPALIVE: | |
253 | eurwdt_ping(); | |
254 | return 0; | |
255 | ||
256 | case WDIOC_SETTIMEOUT: | |
257 | if (copy_from_user(&time, p, sizeof(int))) | |
258 | return -EFAULT; | |
259 | ||
260 | /* Sanity check */ | |
261 | if (time < 0 || time > 255) | |
262 | return -EINVAL; | |
263 | ||
264 | eurwdt_timeout = time; | |
265 | eurwdt_set_timeout(time); | |
266 | /* Fall */ | |
267 | ||
268 | case WDIOC_GETTIMEOUT: | |
269 | return put_user(eurwdt_timeout, p); | |
270 | ||
271 | case WDIOC_SETOPTIONS: | |
272 | if (get_user(options, p)) | |
273 | return -EFAULT; | |
274 | if (options & WDIOS_DISABLECARD) { | |
275 | eurwdt_disable_timer(); | |
276 | retval = 0; | |
277 | } | |
278 | if (options & WDIOS_ENABLECARD) { | |
279 | eurwdt_activate_timer(); | |
280 | eurwdt_ping(); | |
281 | retval = 0; | |
282 | } | |
283 | return retval; | |
284 | } | |
285 | } | |
286 | ||
287 | /** | |
288 | * eurwdt_open: | |
289 | * @inode: inode of device | |
290 | * @file: file handle to device | |
291 | * | |
292 | * The misc device has been opened. The watchdog device is single | |
293 | * open and on opening we load the counter. | |
294 | */ | |
295 | ||
296 | static int eurwdt_open(struct inode *inode, struct file *file) | |
297 | { | |
298 | if (test_and_set_bit(0, &eurwdt_is_open)) | |
299 | return -EBUSY; | |
300 | eurwdt_timeout = WDT_TIMEOUT; /* initial timeout */ | |
301 | /* Activate the WDT */ | |
302 | eurwdt_activate_timer(); | |
303 | return nonseekable_open(inode, file); | |
304 | } | |
305 | ||
306 | /** | |
307 | * eurwdt_release: | |
308 | * @inode: inode to board | |
309 | * @file: file handle to board | |
310 | * | |
311 | * The watchdog has a configurable API. There is a religious dispute | |
312 | * between people who want their watchdog to be able to shut down and | |
313 | * those who want to be sure if the watchdog manager dies the machine | |
314 | * reboots. In the former case we disable the counters, in the latter | |
315 | * case you have to open it again very soon. | |
316 | */ | |
317 | ||
318 | static int eurwdt_release(struct inode *inode, struct file *file) | |
319 | { | |
320 | if (eur_expect_close == 42) { | |
321 | eurwdt_disable_timer(); | |
322 | } else { | |
323 | printk(KERN_CRIT "eurwdt: Unexpected close, not stopping watchdog!\n"); | |
324 | eurwdt_ping(); | |
325 | } | |
326 | clear_bit(0, &eurwdt_is_open); | |
327 | eur_expect_close = 0; | |
328 | return 0; | |
329 | } | |
330 | ||
331 | /** | |
332 | * eurwdt_notify_sys: | |
333 | * @this: our notifier block | |
334 | * @code: the event being reported | |
335 | * @unused: unused | |
336 | * | |
337 | * Our notifier is called on system shutdowns. We want to turn the card | |
338 | * off at reboot otherwise the machine will reboot again during memory | |
339 | * test or worse yet during the following fsck. This would suck, in fact | |
340 | * trust me - if it happens it does suck. | |
341 | */ | |
342 | ||
343 | static int eurwdt_notify_sys(struct notifier_block *this, unsigned long code, | |
344 | void *unused) | |
345 | { | |
346 | if (code == SYS_DOWN || code == SYS_HALT) { | |
347 | /* Turn the card off */ | |
348 | eurwdt_disable_timer(); | |
349 | } | |
350 | ||
351 | return NOTIFY_DONE; | |
352 | } | |
353 | ||
354 | /* | |
355 | * Kernel Interfaces | |
356 | */ | |
357 | ||
358 | ||
62322d25 | 359 | static const struct file_operations eurwdt_fops = { |
1da177e4 LT |
360 | .owner = THIS_MODULE, |
361 | .llseek = no_llseek, | |
362 | .write = eurwdt_write, | |
363 | .ioctl = eurwdt_ioctl, | |
364 | .open = eurwdt_open, | |
365 | .release = eurwdt_release, | |
366 | }; | |
367 | ||
368 | static struct miscdevice eurwdt_miscdev = { | |
369 | .minor = WATCHDOG_MINOR, | |
370 | .name = "watchdog", | |
371 | .fops = &eurwdt_fops, | |
372 | }; | |
373 | ||
374 | /* | |
375 | * The WDT card needs to learn about soft shutdowns in order to | |
376 | * turn the timebomb registers off. | |
377 | */ | |
378 | ||
379 | static struct notifier_block eurwdt_notifier = { | |
380 | .notifier_call = eurwdt_notify_sys, | |
381 | }; | |
382 | ||
383 | /** | |
384 | * cleanup_module: | |
385 | * | |
386 | * Unload the watchdog. You cannot do this with any file handles open. | |
387 | * If your watchdog is set to continue ticking on close and you unload | |
388 | * it, well it keeps ticking. We won't get the interrupt but the board | |
389 | * will not touch PC memory so all is fine. You just have to load a new | |
390 | * module in 60 seconds or reboot. | |
391 | */ | |
392 | ||
393 | static void __exit eurwdt_exit(void) | |
394 | { | |
395 | eurwdt_lock_chip(); | |
396 | ||
397 | misc_deregister(&eurwdt_miscdev); | |
398 | ||
399 | unregister_reboot_notifier(&eurwdt_notifier); | |
400 | release_region(io, 2); | |
401 | free_irq(irq, NULL); | |
402 | } | |
403 | ||
404 | /** | |
405 | * eurwdt_init: | |
406 | * | |
407 | * Set up the WDT watchdog board. After grabbing the resources | |
408 | * we require we need also to unlock the device. | |
409 | * The open() function will actually kick the board off. | |
410 | */ | |
411 | ||
412 | static int __init eurwdt_init(void) | |
413 | { | |
414 | int ret; | |
415 | ||
0f2ed4c6 | 416 | ret = request_irq(irq, eurwdt_interrupt, IRQF_DISABLED, "eurwdt", NULL); |
1da177e4 LT |
417 | if(ret) { |
418 | printk(KERN_ERR "eurwdt: IRQ %d is not free.\n", irq); | |
fb8f7ba0 | 419 | goto out; |
1da177e4 LT |
420 | } |
421 | ||
422 | if (!request_region(io, 2, "eurwdt")) { | |
423 | printk(KERN_ERR "eurwdt: IO %X is not free.\n", io); | |
424 | ret = -EBUSY; | |
425 | goto outirq; | |
426 | } | |
427 | ||
428 | ret = register_reboot_notifier(&eurwdt_notifier); | |
429 | if (ret) { | |
430 | printk(KERN_ERR "eurwdt: can't register reboot notifier (err=%d)\n", ret); | |
431 | goto outreg; | |
432 | } | |
433 | ||
fb8f7ba0 AD |
434 | ret = misc_register(&eurwdt_miscdev); |
435 | if (ret) { | |
436 | printk(KERN_ERR "eurwdt: can't misc_register on minor=%d\n", | |
437 | WATCHDOG_MINOR); | |
438 | goto outreboot; | |
439 | } | |
440 | ||
1da177e4 LT |
441 | eurwdt_unlock_chip(); |
442 | ||
443 | ret = 0; | |
444 | printk(KERN_INFO "Eurotech WDT driver 0.01 at %X (Interrupt %d)" | |
445 | " - timeout event: %s\n", | |
446 | io, irq, (!strcmp("int", ev) ? "int" : "reboot")); | |
447 | ||
448 | out: | |
449 | return ret; | |
450 | ||
fb8f7ba0 AD |
451 | outreboot: |
452 | unregister_reboot_notifier(&eurwdt_notifier); | |
453 | ||
1da177e4 LT |
454 | outreg: |
455 | release_region(io, 2); | |
456 | ||
457 | outirq: | |
458 | free_irq(irq, NULL); | |
1da177e4 LT |
459 | goto out; |
460 | } | |
461 | ||
462 | module_init(eurwdt_init); | |
463 | module_exit(eurwdt_exit); | |
464 | ||
465 | MODULE_AUTHOR("Rodolfo Giometti"); | |
466 | MODULE_DESCRIPTION("Driver for Eurotech CPU-1220/1410 on board watchdog"); | |
467 | MODULE_LICENSE("GPL"); | |
468 | MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR); |