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1 | /* |
2 | * Eurotech CPU-1220/1410/1420 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@lxorguk.ukuu.org.uk>, |
12 | * All Rights Reserved. |
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 | * 2001 - Rodolfo Giometti |
29 | * Initial release |
30 | * |
31 | * 2002/04/25 - Rob Radez |
32 | * clean up #includes |
33 | * clean up locking |
34 | * make __setup param unique |
35 | * proper options in watchdog_info |
36 | * add WDIOC_GETSTATUS and WDIOC_SETOPTIONS ioctls |
37 | * add expect_close support |
38 | * |
39 | * 2002.05.30 - Joel Becker <joel.becker@oracle.com> |
40 | * Added Matt Domsch's nowayout module option. |
41 | */ |
42 | |
43 | /* |
44 | * The eurotech CPU-1220/1410/1420's watchdog is a part |
45 | * of the on-board SUPER I/O device SMSC FDC 37B782. |
46 | */ |
47 | |
48 | #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt |
49 | |
50 | #include <linux/interrupt.h> |
51 | #include <linux/module.h> |
52 | #include <linux/moduleparam.h> |
53 | #include <linux/types.h> |
54 | #include <linux/miscdevice.h> |
55 | #include <linux/watchdog.h> |
56 | #include <linux/fs.h> |
57 | #include <linux/ioport.h> |
58 | #include <linux/notifier.h> |
59 | #include <linux/reboot.h> |
60 | #include <linux/init.h> |
61 | #include <linux/io.h> |
62 | #include <linux/uaccess.h> |
63 | |
64 | |
65 | static unsigned long eurwdt_is_open; |
66 | static int eurwdt_timeout; |
67 | static char eur_expect_close; |
68 | static DEFINE_SPINLOCK(eurwdt_lock); |
69 | |
70 | /* |
71 | * You must set these - there is no sane way to probe for this board. |
72 | */ |
73 | |
74 | static int io = 0x3f0; |
75 | static int irq = 10; |
76 | static char *ev = "int"; |
77 | |
78 | #define WDT_TIMEOUT 60 /* 1 minute */ |
79 | |
80 | static bool nowayout = WATCHDOG_NOWAYOUT; |
81 | module_param(nowayout, bool, 0); |
82 | MODULE_PARM_DESC(nowayout, |
83 | "Watchdog cannot be stopped once started (default=" |
84 | __MODULE_STRING(WATCHDOG_NOWAYOUT) ")"); |
85 | |
86 | /* |
87 | * Some symbolic names |
88 | */ |
89 | |
90 | #define WDT_CTRL_REG 0x30 |
91 | #define WDT_OUTPIN_CFG 0xe2 |
92 | #define WDT_EVENT_INT 0x00 |
93 | #define WDT_EVENT_REBOOT 0x08 |
94 | #define WDT_UNIT_SEL 0xf1 |
95 | #define WDT_UNIT_SECS 0x80 |
96 | #define WDT_TIMEOUT_VAL 0xf2 |
97 | #define WDT_TIMER_CFG 0xf3 |
98 | |
99 | |
100 | module_param(io, int, 0); |
101 | MODULE_PARM_DESC(io, "Eurotech WDT io port (default=0x3f0)"); |
102 | module_param(irq, int, 0); |
103 | MODULE_PARM_DESC(irq, "Eurotech WDT irq (default=10)"); |
104 | module_param(ev, charp, 0); |
105 | MODULE_PARM_DESC(ev, "Eurotech WDT event type (default is `int')"); |
106 | |
107 | |
108 | /* |
109 | * Programming support |
110 | */ |
111 | |
112 | static inline void eurwdt_write_reg(u8 index, u8 data) |
113 | { |
114 | outb(index, io); |
115 | outb(data, io+1); |
116 | } |
117 | |
118 | static inline void eurwdt_lock_chip(void) |
119 | { |
120 | outb(0xaa, io); |
121 | } |
122 | |
123 | static inline void eurwdt_unlock_chip(void) |
124 | { |
125 | outb(0x55, io); |
126 | eurwdt_write_reg(0x07, 0x08); /* set the logical device */ |
127 | } |
128 | |
129 | static inline void eurwdt_set_timeout(int timeout) |
130 | { |
131 | eurwdt_write_reg(WDT_TIMEOUT_VAL, (u8) timeout); |
132 | } |
133 | |
134 | static inline void eurwdt_disable_timer(void) |
135 | { |
136 | eurwdt_set_timeout(0); |
137 | } |
138 | |
139 | static void eurwdt_activate_timer(void) |
140 | { |
141 | eurwdt_disable_timer(); |
142 | eurwdt_write_reg(WDT_CTRL_REG, 0x01); /* activate the WDT */ |
143 | eurwdt_write_reg(WDT_OUTPIN_CFG, |
144 | !strcmp("int", ev) ? WDT_EVENT_INT : WDT_EVENT_REBOOT); |
145 | |
146 | /* Setting interrupt line */ |
147 | if (irq == 2 || irq > 15 || irq < 0) { |
148 | pr_err("invalid irq number\n"); |
149 | irq = 0; /* if invalid we disable interrupt */ |
150 | } |
151 | if (irq == 0) |
152 | pr_info("interrupt disabled\n"); |
153 | |
154 | eurwdt_write_reg(WDT_TIMER_CFG, irq << 4); |
155 | |
156 | eurwdt_write_reg(WDT_UNIT_SEL, WDT_UNIT_SECS); /* we use seconds */ |
157 | eurwdt_set_timeout(0); /* the default timeout */ |
158 | } |
159 | |
160 | |
161 | /* |
162 | * Kernel methods. |
163 | */ |
164 | |
165 | static irqreturn_t eurwdt_interrupt(int irq, void *dev_id) |
166 | { |
167 | pr_crit("timeout WDT timeout\n"); |
168 | |
169 | #ifdef ONLY_TESTING |
170 | pr_crit("Would Reboot\n"); |
171 | #else |
172 | pr_crit("Initiating system reboot\n"); |
173 | emergency_restart(); |
174 | #endif |
175 | return IRQ_HANDLED; |
176 | } |
177 | |
178 | |
179 | /** |
180 | * eurwdt_ping: |
181 | * |
182 | * Reload counter one with the watchdog timeout. |
183 | */ |
184 | |
185 | static void eurwdt_ping(void) |
186 | { |
187 | /* Write the watchdog default value */ |
188 | eurwdt_set_timeout(eurwdt_timeout); |
189 | } |
190 | |
191 | /** |
192 | * eurwdt_write: |
193 | * @file: file handle to the watchdog |
194 | * @buf: buffer to write (unused as data does not matter here |
195 | * @count: count of bytes |
196 | * @ppos: pointer to the position to write. No seeks allowed |
197 | * |
198 | * A write to a watchdog device is defined as a keepalive signal. Any |
199 | * write of data will do, as we we don't define content meaning. |
200 | */ |
201 | |
202 | static ssize_t eurwdt_write(struct file *file, const char __user *buf, |
203 | size_t count, loff_t *ppos) |
204 | { |
205 | if (count) { |
206 | if (!nowayout) { |
207 | size_t i; |
208 | |
209 | eur_expect_close = 0; |
210 | |
211 | for (i = 0; i != count; i++) { |
212 | char c; |
213 | if (get_user(c, buf + i)) |
214 | return -EFAULT; |
215 | if (c == 'V') |
216 | eur_expect_close = 42; |
217 | } |
218 | } |
219 | spin_lock(&eurwdt_lock); |
220 | eurwdt_ping(); /* the default timeout */ |
221 | spin_unlock(&eurwdt_lock); |
222 | } |
223 | return count; |
224 | } |
225 | |
226 | /** |
227 | * eurwdt_ioctl: |
228 | * @file: file handle to the device |
229 | * @cmd: watchdog command |
230 | * @arg: argument pointer |
231 | * |
232 | * The watchdog API defines a common set of functions for all watchdogs |
233 | * according to their available features. |
234 | */ |
235 | |
236 | static long eurwdt_ioctl(struct file *file, |
237 | unsigned int cmd, unsigned long arg) |
238 | { |
239 | void __user *argp = (void __user *)arg; |
240 | int __user *p = argp; |
241 | static const struct watchdog_info ident = { |
242 | .options = WDIOF_KEEPALIVEPING | WDIOF_SETTIMEOUT |
243 | | WDIOF_MAGICCLOSE, |
244 | .firmware_version = 1, |
245 | .identity = "WDT Eurotech CPU-1220/1410", |
246 | }; |
247 | |
248 | int time; |
249 | int options, retval = -EINVAL; |
250 | |
251 | switch (cmd) { |
252 | case WDIOC_GETSUPPORT: |
253 | return copy_to_user(argp, &ident, sizeof(ident)) ? -EFAULT : 0; |
254 | |
255 | case WDIOC_GETSTATUS: |
256 | case WDIOC_GETBOOTSTATUS: |
257 | return put_user(0, p); |
258 | |
259 | case WDIOC_SETOPTIONS: |
260 | if (get_user(options, p)) |
261 | return -EFAULT; |
262 | spin_lock(&eurwdt_lock); |
263 | if (options & WDIOS_DISABLECARD) { |
264 | eurwdt_disable_timer(); |
265 | retval = 0; |
266 | } |
267 | if (options & WDIOS_ENABLECARD) { |
268 | eurwdt_activate_timer(); |
269 | eurwdt_ping(); |
270 | retval = 0; |
271 | } |
272 | spin_unlock(&eurwdt_lock); |
273 | return retval; |
274 | |
275 | case WDIOC_KEEPALIVE: |
276 | spin_lock(&eurwdt_lock); |
277 | eurwdt_ping(); |
278 | spin_unlock(&eurwdt_lock); |
279 | return 0; |
280 | |
281 | case WDIOC_SETTIMEOUT: |
282 | if (copy_from_user(&time, p, sizeof(int))) |
283 | return -EFAULT; |
284 | |
285 | /* Sanity check */ |
286 | if (time < 0 || time > 255) |
287 | return -EINVAL; |
288 | |
289 | spin_lock(&eurwdt_lock); |
290 | eurwdt_timeout = time; |
291 | eurwdt_set_timeout(time); |
292 | spin_unlock(&eurwdt_lock); |
293 | /* Fall */ |
294 | |
295 | case WDIOC_GETTIMEOUT: |
296 | return put_user(eurwdt_timeout, p); |
297 | |
298 | default: |
299 | return -ENOTTY; |
300 | } |
301 | } |
302 | |
303 | /** |
304 | * eurwdt_open: |
305 | * @inode: inode of device |
306 | * @file: file handle to device |
307 | * |
308 | * The misc device has been opened. The watchdog device is single |
309 | * open and on opening we load the counter. |
310 | */ |
311 | |
312 | static int eurwdt_open(struct inode *inode, struct file *file) |
313 | { |
314 | if (test_and_set_bit(0, &eurwdt_is_open)) |
315 | return -EBUSY; |
316 | eurwdt_timeout = WDT_TIMEOUT; /* initial timeout */ |
317 | /* Activate the WDT */ |
318 | eurwdt_activate_timer(); |
319 | return nonseekable_open(inode, file); |
320 | } |
321 | |
322 | /** |
323 | * eurwdt_release: |
324 | * @inode: inode to board |
325 | * @file: file handle to board |
326 | * |
327 | * The watchdog has a configurable API. There is a religious dispute |
328 | * between people who want their watchdog to be able to shut down and |
329 | * those who want to be sure if the watchdog manager dies the machine |
330 | * reboots. In the former case we disable the counters, in the latter |
331 | * case you have to open it again very soon. |
332 | */ |
333 | |
334 | static int eurwdt_release(struct inode *inode, struct file *file) |
335 | { |
336 | if (eur_expect_close == 42) |
337 | eurwdt_disable_timer(); |
338 | else { |
339 | pr_crit("Unexpected close, not stopping watchdog!\n"); |
340 | eurwdt_ping(); |
341 | } |
342 | clear_bit(0, &eurwdt_is_open); |
343 | eur_expect_close = 0; |
344 | return 0; |
345 | } |
346 | |
347 | /** |
348 | * eurwdt_notify_sys: |
349 | * @this: our notifier block |
350 | * @code: the event being reported |
351 | * @unused: unused |
352 | * |
353 | * Our notifier is called on system shutdowns. We want to turn the card |
354 | * off at reboot otherwise the machine will reboot again during memory |
355 | * test or worse yet during the following fsck. This would suck, in fact |
356 | * trust me - if it happens it does suck. |
357 | */ |
358 | |
359 | static int eurwdt_notify_sys(struct notifier_block *this, unsigned long code, |
360 | void *unused) |
361 | { |
362 | if (code == SYS_DOWN || code == SYS_HALT) |
363 | eurwdt_disable_timer(); /* Turn the card off */ |
364 | |
365 | return NOTIFY_DONE; |
366 | } |
367 | |
368 | /* |
369 | * Kernel Interfaces |
370 | */ |
371 | |
372 | |
373 | static const struct file_operations eurwdt_fops = { |
374 | .owner = THIS_MODULE, |
375 | .llseek = no_llseek, |
376 | .write = eurwdt_write, |
377 | .unlocked_ioctl = eurwdt_ioctl, |
378 | .open = eurwdt_open, |
379 | .release = eurwdt_release, |
380 | }; |
381 | |
382 | static struct miscdevice eurwdt_miscdev = { |
383 | .minor = WATCHDOG_MINOR, |
384 | .name = "watchdog", |
385 | .fops = &eurwdt_fops, |
386 | }; |
387 | |
388 | /* |
389 | * The WDT card needs to learn about soft shutdowns in order to |
390 | * turn the timebomb registers off. |
391 | */ |
392 | |
393 | static struct notifier_block eurwdt_notifier = { |
394 | .notifier_call = eurwdt_notify_sys, |
395 | }; |
396 | |
397 | /** |
398 | * cleanup_module: |
399 | * |
400 | * Unload the watchdog. You cannot do this with any file handles open. |
401 | * If your watchdog is set to continue ticking on close and you unload |
402 | * it, well it keeps ticking. We won't get the interrupt but the board |
403 | * will not touch PC memory so all is fine. You just have to load a new |
404 | * module in 60 seconds or reboot. |
405 | */ |
406 | |
407 | static void __exit eurwdt_exit(void) |
408 | { |
409 | eurwdt_lock_chip(); |
410 | |
411 | misc_deregister(&eurwdt_miscdev); |
412 | |
413 | unregister_reboot_notifier(&eurwdt_notifier); |
414 | release_region(io, 2); |
415 | free_irq(irq, NULL); |
416 | } |
417 | |
418 | /** |
419 | * eurwdt_init: |
420 | * |
421 | * Set up the WDT watchdog board. After grabbing the resources |
422 | * we require we need also to unlock the device. |
423 | * The open() function will actually kick the board off. |
424 | */ |
425 | |
426 | static int __init eurwdt_init(void) |
427 | { |
428 | int ret; |
429 | |
430 | ret = request_irq(irq, eurwdt_interrupt, 0, "eurwdt", NULL); |
431 | if (ret) { |
432 | pr_err("IRQ %d is not free\n", irq); |
433 | goto out; |
434 | } |
435 | |
436 | if (!request_region(io, 2, "eurwdt")) { |
437 | pr_err("IO %X is not free\n", io); |
438 | ret = -EBUSY; |
439 | goto outirq; |
440 | } |
441 | |
442 | ret = register_reboot_notifier(&eurwdt_notifier); |
443 | if (ret) { |
444 | pr_err("can't register reboot notifier (err=%d)\n", ret); |
445 | goto outreg; |
446 | } |
447 | |
448 | ret = misc_register(&eurwdt_miscdev); |
449 | if (ret) { |
450 | pr_err("can't misc_register on minor=%d\n", WATCHDOG_MINOR); |
451 | goto outreboot; |
452 | } |
453 | |
454 | eurwdt_unlock_chip(); |
455 | |
456 | ret = 0; |
457 | pr_info("Eurotech WDT driver 0.01 at %X (Interrupt %d) - timeout event: %s\n", |
458 | io, irq, (!strcmp("int", ev) ? "int" : "reboot")); |
459 | |
460 | out: |
461 | return ret; |
462 | |
463 | outreboot: |
464 | unregister_reboot_notifier(&eurwdt_notifier); |
465 | |
466 | outreg: |
467 | release_region(io, 2); |
468 | |
469 | outirq: |
470 | free_irq(irq, NULL); |
471 | goto out; |
472 | } |
473 | |
474 | module_init(eurwdt_init); |
475 | module_exit(eurwdt_exit); |
476 | |
477 | MODULE_AUTHOR("Rodolfo Giometti"); |
478 | MODULE_DESCRIPTION("Driver for Eurotech CPU-1220/1410 on board watchdog"); |
479 | MODULE_LICENSE("GPL"); |
480 | MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR); |
481 |
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