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Linus Torvalds1da177e2005-04-16 15:20:36 -07001/*
Wim Van Sebroeck0f112a82007-08-09 19:38:00 +00002 * Eurotech CPU-1220/1410/1420 on board WDT driver
Linus Torvalds1da177e2005-04-16 15:20:36 -07003 *
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 *
Wim Van Sebroeck0f112a82007-08-09 19:38:00 +000028 * 2001 - Rodolfo Giometti
29 * Initial release
30 *
Linus Torvalds1da177e2005-04-16 15:20:36 -070031 * 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 *
Linus Torvalds1da177e2005-04-16 15:20:36 -070039 * 2002.05.30 - Joel Becker <joel.becker@oracle.com>
40 * Added Matt Domsch's nowayout module option.
41 */
42
Wim Van Sebroeck0f112a82007-08-09 19:38:00 +000043/*
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
Linus Torvalds1da177e2005-04-16 15:20:36 -070048#include <linux/interrupt.h>
49#include <linux/module.h>
50#include <linux/moduleparam.h>
51#include <linux/types.h>
52#include <linux/miscdevice.h>
53#include <linux/watchdog.h>
54#include <linux/fs.h>
55#include <linux/ioport.h>
56#include <linux/notifier.h>
57#include <linux/reboot.h>
58#include <linux/init.h>
59
60#include <asm/io.h>
61#include <asm/uaccess.h>
62#include <asm/system.h>
63
64static unsigned long eurwdt_is_open;
65static int eurwdt_timeout;
66static char eur_expect_close;
67
68/*
69 * You must set these - there is no sane way to probe for this board.
70 * You can use eurwdt=x,y to set these now.
71 */
72
73static int io = 0x3f0;
74static int irq = 10;
75static char *ev = "int";
76
77#define WDT_TIMEOUT 60 /* 1 minute */
78
Andrey Panin4bfdf372005-07-27 11:43:58 -070079static int nowayout = WATCHDOG_NOWAYOUT;
Linus Torvalds1da177e2005-04-16 15:20:36 -070080module_param(nowayout, int, 0);
Wim Van Sebroeckbffda5c2007-01-27 20:54:24 +010081MODULE_PARM_DESC(nowayout, "Watchdog cannot be stopped once started (default=" __MODULE_STRING(WATCHDOG_NOWAYOUT) ")");
Linus Torvalds1da177e2005-04-16 15:20:36 -070082
83/*
84 * Some symbolic names
85 */
86
87#define WDT_CTRL_REG 0x30
88#define WDT_OUTPIN_CFG 0xe2
89#define WDT_EVENT_INT 0x00
90#define WDT_EVENT_REBOOT 0x08
91#define WDT_UNIT_SEL 0xf1
92#define WDT_UNIT_SECS 0x80
93#define WDT_TIMEOUT_VAL 0xf2
94#define WDT_TIMER_CFG 0xf3
95
96
97module_param(io, int, 0);
98MODULE_PARM_DESC(io, "Eurotech WDT io port (default=0x3f0)");
99module_param(irq, int, 0);
100MODULE_PARM_DESC(irq, "Eurotech WDT irq (default=10)");
101module_param(ev, charp, 0);
102MODULE_PARM_DESC(ev, "Eurotech WDT event type (default is `int')");
103
104
105/*
106 * Programming support
107 */
108
109static inline void eurwdt_write_reg(u8 index, u8 data)
110{
111 outb(index, io);
112 outb(data, io+1);
113}
114
115static inline void eurwdt_lock_chip(void)
116{
117 outb(0xaa, io);
118}
119
120static inline void eurwdt_unlock_chip(void)
121{
122 outb(0x55, io);
123 eurwdt_write_reg(0x07, 0x08); /* set the logical device */
124}
125
126static inline void eurwdt_set_timeout(int timeout)
127{
128 eurwdt_write_reg(WDT_TIMEOUT_VAL, (u8) timeout);
129}
130
131static inline void eurwdt_disable_timer(void)
132{
133 eurwdt_set_timeout(0);
134}
135
136static void eurwdt_activate_timer(void)
137{
138 eurwdt_disable_timer();
139 eurwdt_write_reg(WDT_CTRL_REG, 0x01); /* activate the WDT */
140 eurwdt_write_reg(WDT_OUTPIN_CFG, !strcmp("int", ev) ? WDT_EVENT_INT : WDT_EVENT_REBOOT);
141
142 /* Setting interrupt line */
143 if (irq == 2 || irq > 15 || irq < 0) {
144 printk(KERN_ERR ": invalid irq number\n");
145 irq = 0; /* if invalid we disable interrupt */
146 }
147 if (irq == 0)
148 printk(KERN_INFO ": interrupt disabled\n");
149
150 eurwdt_write_reg(WDT_TIMER_CFG, irq<<4);
151
152 eurwdt_write_reg(WDT_UNIT_SEL, WDT_UNIT_SECS); /* we use seconds */
153 eurwdt_set_timeout(0); /* the default timeout */
154}
155
156
157/*
158 * Kernel methods.
159 */
160
David Howells7d12e782006-10-05 14:55:46 +0100161static irqreturn_t eurwdt_interrupt(int irq, void *dev_id)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700162{
163 printk(KERN_CRIT "timeout WDT timeout\n");
164
165#ifdef ONLY_TESTING
166 printk(KERN_CRIT "Would Reboot.\n");
167#else
168 printk(KERN_CRIT "Initiating system reboot.\n");
Andrew Mortoncc1d3a92005-07-26 21:41:37 -0700169 emergency_restart();
Linus Torvalds1da177e2005-04-16 15:20:36 -0700170#endif
171 return IRQ_HANDLED;
172}
173
174
175/**
176 * eurwdt_ping:
177 *
178 * Reload counter one with the watchdog timeout.
179 */
180
181static void eurwdt_ping(void)
182{
183 /* Write the watchdog default value */
184 eurwdt_set_timeout(eurwdt_timeout);
185}
186
187/**
188 * eurwdt_write:
189 * @file: file handle to the watchdog
190 * @buf: buffer to write (unused as data does not matter here
191 * @count: count of bytes
192 * @ppos: pointer to the position to write. No seeks allowed
193 *
194 * A write to a watchdog device is defined as a keepalive signal. Any
195 * write of data will do, as we we don't define content meaning.
196 */
197
198static ssize_t eurwdt_write(struct file *file, const char __user *buf,
199size_t count, loff_t *ppos)
200{
201 if (count) {
202 if (!nowayout) {
203 size_t i;
204
205 eur_expect_close = 0;
206
207 for (i = 0; i != count; i++) {
208 char c;
209 if(get_user(c, buf+i))
210 return -EFAULT;
211 if (c == 'V')
212 eur_expect_close = 42;
213 }
214 }
215 eurwdt_ping(); /* the default timeout */
216 }
217
218 return count;
219}
220
221/**
222 * eurwdt_ioctl:
223 * @inode: inode of the device
224 * @file: file handle to the device
225 * @cmd: watchdog command
226 * @arg: argument pointer
227 *
228 * The watchdog API defines a common set of functions for all watchdogs
229 * according to their available features.
230 */
231
232static int eurwdt_ioctl(struct inode *inode, struct file *file,
233 unsigned int cmd, unsigned long arg)
234{
235 void __user *argp = (void __user *)arg;
236 int __user *p = argp;
237 static struct watchdog_info ident = {
238 .options = WDIOF_KEEPALIVEPING | WDIOF_SETTIMEOUT | WDIOF_MAGICCLOSE,
239 .firmware_version = 1,
240 .identity = "WDT Eurotech CPU-1220/1410",
241 };
242
243 int time;
244 int options, retval = -EINVAL;
245
246 switch(cmd) {
247 default:
Samuel Tardieu795b89d2006-09-09 17:34:31 +0200248 return -ENOTTY;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700249
250 case WDIOC_GETSUPPORT:
251 return copy_to_user(argp, &ident, sizeof(ident)) ? -EFAULT : 0;
252
253 case WDIOC_GETSTATUS:
254 case WDIOC_GETBOOTSTATUS:
255 return put_user(0, p);
256
257 case WDIOC_KEEPALIVE:
258 eurwdt_ping();
259 return 0;
260
261 case WDIOC_SETTIMEOUT:
262 if (copy_from_user(&time, p, sizeof(int)))
263 return -EFAULT;
264
265 /* Sanity check */
266 if (time < 0 || time > 255)
267 return -EINVAL;
268
269 eurwdt_timeout = time;
270 eurwdt_set_timeout(time);
271 /* Fall */
272
273 case WDIOC_GETTIMEOUT:
274 return put_user(eurwdt_timeout, p);
275
276 case WDIOC_SETOPTIONS:
277 if (get_user(options, p))
278 return -EFAULT;
279 if (options & WDIOS_DISABLECARD) {
280 eurwdt_disable_timer();
281 retval = 0;
282 }
283 if (options & WDIOS_ENABLECARD) {
284 eurwdt_activate_timer();
285 eurwdt_ping();
286 retval = 0;
287 }
288 return retval;
289 }
290}
291
292/**
293 * eurwdt_open:
294 * @inode: inode of device
295 * @file: file handle to device
296 *
297 * The misc device has been opened. The watchdog device is single
298 * open and on opening we load the counter.
299 */
300
301static int eurwdt_open(struct inode *inode, struct file *file)
302{
303 if (test_and_set_bit(0, &eurwdt_is_open))
304 return -EBUSY;
305 eurwdt_timeout = WDT_TIMEOUT; /* initial timeout */
306 /* Activate the WDT */
307 eurwdt_activate_timer();
308 return nonseekable_open(inode, file);
309}
310
311/**
312 * eurwdt_release:
313 * @inode: inode to board
314 * @file: file handle to board
315 *
316 * The watchdog has a configurable API. There is a religious dispute
317 * between people who want their watchdog to be able to shut down and
318 * those who want to be sure if the watchdog manager dies the machine
319 * reboots. In the former case we disable the counters, in the latter
320 * case you have to open it again very soon.
321 */
322
323static int eurwdt_release(struct inode *inode, struct file *file)
324{
325 if (eur_expect_close == 42) {
326 eurwdt_disable_timer();
327 } else {
328 printk(KERN_CRIT "eurwdt: Unexpected close, not stopping watchdog!\n");
329 eurwdt_ping();
330 }
331 clear_bit(0, &eurwdt_is_open);
332 eur_expect_close = 0;
333 return 0;
334}
335
336/**
337 * eurwdt_notify_sys:
338 * @this: our notifier block
339 * @code: the event being reported
340 * @unused: unused
341 *
342 * Our notifier is called on system shutdowns. We want to turn the card
343 * off at reboot otherwise the machine will reboot again during memory
344 * test or worse yet during the following fsck. This would suck, in fact
345 * trust me - if it happens it does suck.
346 */
347
348static int eurwdt_notify_sys(struct notifier_block *this, unsigned long code,
349 void *unused)
350{
351 if (code == SYS_DOWN || code == SYS_HALT) {
352 /* Turn the card off */
353 eurwdt_disable_timer();
354 }
355
356 return NOTIFY_DONE;
357}
358
359/*
360 * Kernel Interfaces
361 */
362
363
Arjan van de Ven62322d22006-07-03 00:24:21 -0700364static const struct file_operations eurwdt_fops = {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700365 .owner = THIS_MODULE,
366 .llseek = no_llseek,
367 .write = eurwdt_write,
368 .ioctl = eurwdt_ioctl,
369 .open = eurwdt_open,
370 .release = eurwdt_release,
371};
372
373static struct miscdevice eurwdt_miscdev = {
374 .minor = WATCHDOG_MINOR,
375 .name = "watchdog",
376 .fops = &eurwdt_fops,
377};
378
379/*
380 * The WDT card needs to learn about soft shutdowns in order to
381 * turn the timebomb registers off.
382 */
383
384static struct notifier_block eurwdt_notifier = {
385 .notifier_call = eurwdt_notify_sys,
386};
387
388/**
389 * cleanup_module:
390 *
391 * Unload the watchdog. You cannot do this with any file handles open.
392 * If your watchdog is set to continue ticking on close and you unload
393 * it, well it keeps ticking. We won't get the interrupt but the board
394 * will not touch PC memory so all is fine. You just have to load a new
395 * module in 60 seconds or reboot.
396 */
397
398static void __exit eurwdt_exit(void)
399{
400 eurwdt_lock_chip();
401
402 misc_deregister(&eurwdt_miscdev);
403
404 unregister_reboot_notifier(&eurwdt_notifier);
405 release_region(io, 2);
406 free_irq(irq, NULL);
407}
408
409/**
410 * eurwdt_init:
411 *
412 * Set up the WDT watchdog board. After grabbing the resources
413 * we require we need also to unlock the device.
414 * The open() function will actually kick the board off.
415 */
416
417static int __init eurwdt_init(void)
418{
419 int ret;
420
Thomas Gleixner0f2ed4c2006-07-01 19:29:33 -0700421 ret = request_irq(irq, eurwdt_interrupt, IRQF_DISABLED, "eurwdt", NULL);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700422 if(ret) {
423 printk(KERN_ERR "eurwdt: IRQ %d is not free.\n", irq);
Alexey Dobriyanfb8f7ba2007-03-24 15:58:12 +0300424 goto out;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700425 }
426
427 if (!request_region(io, 2, "eurwdt")) {
428 printk(KERN_ERR "eurwdt: IO %X is not free.\n", io);
429 ret = -EBUSY;
430 goto outirq;
431 }
432
433 ret = register_reboot_notifier(&eurwdt_notifier);
434 if (ret) {
435 printk(KERN_ERR "eurwdt: can't register reboot notifier (err=%d)\n", ret);
436 goto outreg;
437 }
438
Alexey Dobriyanfb8f7ba2007-03-24 15:58:12 +0300439 ret = misc_register(&eurwdt_miscdev);
440 if (ret) {
441 printk(KERN_ERR "eurwdt: can't misc_register on minor=%d\n",
442 WATCHDOG_MINOR);
443 goto outreboot;
444 }
445
Linus Torvalds1da177e2005-04-16 15:20:36 -0700446 eurwdt_unlock_chip();
447
448 ret = 0;
449 printk(KERN_INFO "Eurotech WDT driver 0.01 at %X (Interrupt %d)"
450 " - timeout event: %s\n",
451 io, irq, (!strcmp("int", ev) ? "int" : "reboot"));
452
453out:
454 return ret;
455
Alexey Dobriyanfb8f7ba2007-03-24 15:58:12 +0300456outreboot:
457 unregister_reboot_notifier(&eurwdt_notifier);
458
Linus Torvalds1da177e2005-04-16 15:20:36 -0700459outreg:
460 release_region(io, 2);
461
462outirq:
463 free_irq(irq, NULL);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700464 goto out;
465}
466
467module_init(eurwdt_init);
468module_exit(eurwdt_exit);
469
470MODULE_AUTHOR("Rodolfo Giometti");
471MODULE_DESCRIPTION("Driver for Eurotech CPU-1220/1410 on board watchdog");
472MODULE_LICENSE("GPL");
473MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR);