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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 *
Wim Van Sebroeck143a2e52009-03-18 08:35:09 +000011 * (c) Copyright 1996-1997 Alan Cox <alan@lxorguk.ukuu.org.uk>,
Alan Cox29fa0582008-10-27 15:17:56 +000012 * All Rights Reserved.
Linus Torvalds1da177e2005-04-16 15:20:36 -070013 *
Wim Van Sebroeck143a2e52009-03-18 08:35:09 +000014 * 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.
Linus Torvalds1da177e2005-04-16 15:20:36 -070018 *
Wim Van Sebroeck143a2e52009-03-18 08:35:09 +000019 * 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.
Linus Torvalds1da177e2005-04-16 15:20:36 -070022 *
Wim Van Sebroeck143a2e52009-03-18 08:35:09 +000023 * (c) Copyright 1995 Alan Cox <alan@lxorguk.ukuu.org.uk>*
Linus Torvalds1da177e2005-04-16 15:20:36 -070024 */
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>
Wim Van Sebroeck143a2e52009-03-18 08:35:09 +000040 * Added Matt Domsch's nowayout module option.
Linus Torvalds1da177e2005-04-16 15:20:36 -070041 */
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>
Alan Cox89ea2422008-05-19 14:05:41 +010059#include <linux/io.h>
60#include <linux/uaccess.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070061
Linus Torvalds1da177e2005-04-16 15:20:36 -070062#include <asm/system.h>
63
64static unsigned long eurwdt_is_open;
65static int eurwdt_timeout;
66static char eur_expect_close;
Axel Lin1334f322011-11-29 13:54:01 +080067static DEFINE_SPINLOCK(eurwdt_lock);
Linus Torvalds1da177e2005-04-16 15:20:36 -070068
69/*
70 * You must set these - there is no sane way to probe for this board.
Linus Torvalds1da177e2005-04-16 15:20:36 -070071 */
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);
Alan Cox89ea2422008-05-19 14:05:41 +010081MODULE_PARM_DESC(nowayout,
82 "Watchdog cannot be stopped once started (default="
83 __MODULE_STRING(WATCHDOG_NOWAYOUT) ")");
Linus Torvalds1da177e2005-04-16 15:20:36 -070084
85/*
86 * Some symbolic names
87 */
88
89#define WDT_CTRL_REG 0x30
90#define WDT_OUTPIN_CFG 0xe2
91#define WDT_EVENT_INT 0x00
92#define WDT_EVENT_REBOOT 0x08
93#define WDT_UNIT_SEL 0xf1
94#define WDT_UNIT_SECS 0x80
95#define WDT_TIMEOUT_VAL 0xf2
96#define WDT_TIMER_CFG 0xf3
97
98
99module_param(io, int, 0);
100MODULE_PARM_DESC(io, "Eurotech WDT io port (default=0x3f0)");
101module_param(irq, int, 0);
102MODULE_PARM_DESC(irq, "Eurotech WDT irq (default=10)");
103module_param(ev, charp, 0);
104MODULE_PARM_DESC(ev, "Eurotech WDT event type (default is `int')");
105
106
107/*
108 * Programming support
109 */
110
111static inline void eurwdt_write_reg(u8 index, u8 data)
112{
113 outb(index, io);
114 outb(data, io+1);
115}
116
117static inline void eurwdt_lock_chip(void)
118{
119 outb(0xaa, io);
120}
121
122static inline void eurwdt_unlock_chip(void)
123{
124 outb(0x55, io);
125 eurwdt_write_reg(0x07, 0x08); /* set the logical device */
126}
127
128static inline void eurwdt_set_timeout(int timeout)
129{
130 eurwdt_write_reg(WDT_TIMEOUT_VAL, (u8) timeout);
131}
132
133static inline void eurwdt_disable_timer(void)
134{
135 eurwdt_set_timeout(0);
136}
137
138static void eurwdt_activate_timer(void)
139{
140 eurwdt_disable_timer();
141 eurwdt_write_reg(WDT_CTRL_REG, 0x01); /* activate the WDT */
Alan Cox89ea2422008-05-19 14:05:41 +0100142 eurwdt_write_reg(WDT_OUTPIN_CFG,
143 !strcmp("int", ev) ? WDT_EVENT_INT : WDT_EVENT_REBOOT);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700144
145 /* Setting interrupt line */
146 if (irq == 2 || irq > 15 || irq < 0) {
147 printk(KERN_ERR ": invalid irq number\n");
148 irq = 0; /* if invalid we disable interrupt */
149 }
150 if (irq == 0)
151 printk(KERN_INFO ": interrupt disabled\n");
152
Wim Van Sebroeck143a2e52009-03-18 08:35:09 +0000153 eurwdt_write_reg(WDT_TIMER_CFG, irq << 4);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700154
155 eurwdt_write_reg(WDT_UNIT_SEL, WDT_UNIT_SECS); /* we use seconds */
156 eurwdt_set_timeout(0); /* the default timeout */
157}
158
159
160/*
161 * Kernel methods.
162 */
163
David Howells7d12e782006-10-05 14:55:46 +0100164static irqreturn_t eurwdt_interrupt(int irq, void *dev_id)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700165{
166 printk(KERN_CRIT "timeout WDT timeout\n");
167
168#ifdef ONLY_TESTING
169 printk(KERN_CRIT "Would Reboot.\n");
170#else
171 printk(KERN_CRIT "Initiating system reboot.\n");
Andrew Mortoncc1d3a92005-07-26 21:41:37 -0700172 emergency_restart();
Linus Torvalds1da177e2005-04-16 15:20:36 -0700173#endif
174 return IRQ_HANDLED;
175}
176
177
178/**
179 * eurwdt_ping:
180 *
181 * Reload counter one with the watchdog timeout.
182 */
183
184static void eurwdt_ping(void)
185{
186 /* Write the watchdog default value */
187 eurwdt_set_timeout(eurwdt_timeout);
188}
189
190/**
191 * eurwdt_write:
192 * @file: file handle to the watchdog
193 * @buf: buffer to write (unused as data does not matter here
194 * @count: count of bytes
195 * @ppos: pointer to the position to write. No seeks allowed
196 *
197 * A write to a watchdog device is defined as a keepalive signal. Any
198 * write of data will do, as we we don't define content meaning.
199 */
200
201static ssize_t eurwdt_write(struct file *file, const char __user *buf,
202size_t count, loff_t *ppos)
203{
Wim Van Sebroeck5f3b2752011-02-23 20:04:38 +0000204 if (count) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700205 if (!nowayout) {
206 size_t i;
207
208 eur_expect_close = 0;
209
210 for (i = 0; i != count; i++) {
211 char c;
Wim Van Sebroeck7944d3a2008-08-06 20:19:41 +0000212 if (get_user(c, buf + i))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700213 return -EFAULT;
214 if (c == 'V')
215 eur_expect_close = 42;
216 }
217 }
Alan Cox89ea2422008-05-19 14:05:41 +0100218 spin_lock(&eurwdt_lock);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700219 eurwdt_ping(); /* the default timeout */
Alan Cox89ea2422008-05-19 14:05:41 +0100220 spin_unlock(&eurwdt_lock);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700221 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700222 return count;
223}
224
225/**
226 * eurwdt_ioctl:
Linus Torvalds1da177e2005-04-16 15:20:36 -0700227 * @file: file handle to the device
228 * @cmd: watchdog command
229 * @arg: argument pointer
230 *
231 * The watchdog API defines a common set of functions for all watchdogs
232 * according to their available features.
233 */
234
Alan Cox89ea2422008-05-19 14:05:41 +0100235static long eurwdt_ioctl(struct file *file,
236 unsigned int cmd, unsigned long arg)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700237{
238 void __user *argp = (void __user *)arg;
239 int __user *p = argp;
Wim Van Sebroeck42747d72009-12-26 18:55:22 +0000240 static const struct watchdog_info ident = {
Alan Cox89ea2422008-05-19 14:05:41 +0100241 .options = WDIOF_KEEPALIVEPING | WDIOF_SETTIMEOUT
242 | WDIOF_MAGICCLOSE,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700243 .firmware_version = 1,
244 .identity = "WDT Eurotech CPU-1220/1410",
245 };
246
247 int time;
248 int options, retval = -EINVAL;
249
Alan Cox89ea2422008-05-19 14:05:41 +0100250 switch (cmd) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700251 case WDIOC_GETSUPPORT:
252 return copy_to_user(argp, &ident, sizeof(ident)) ? -EFAULT : 0;
253
254 case WDIOC_GETSTATUS:
255 case WDIOC_GETBOOTSTATUS:
256 return put_user(0, p);
257
Wim Van Sebroeck0c060902008-07-18 11:41:17 +0000258 case WDIOC_SETOPTIONS:
259 if (get_user(options, p))
260 return -EFAULT;
261 spin_lock(&eurwdt_lock);
262 if (options & WDIOS_DISABLECARD) {
263 eurwdt_disable_timer();
264 retval = 0;
265 }
266 if (options & WDIOS_ENABLECARD) {
267 eurwdt_activate_timer();
268 eurwdt_ping();
269 retval = 0;
270 }
271 spin_unlock(&eurwdt_lock);
272 return retval;
273
Linus Torvalds1da177e2005-04-16 15:20:36 -0700274 case WDIOC_KEEPALIVE:
Alan Cox89ea2422008-05-19 14:05:41 +0100275 spin_lock(&eurwdt_lock);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700276 eurwdt_ping();
Alan Cox89ea2422008-05-19 14:05:41 +0100277 spin_unlock(&eurwdt_lock);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700278 return 0;
279
280 case WDIOC_SETTIMEOUT:
281 if (copy_from_user(&time, p, sizeof(int)))
282 return -EFAULT;
283
284 /* Sanity check */
285 if (time < 0 || time > 255)
286 return -EINVAL;
287
Alan Cox89ea2422008-05-19 14:05:41 +0100288 spin_lock(&eurwdt_lock);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700289 eurwdt_timeout = time;
290 eurwdt_set_timeout(time);
Alan Cox89ea2422008-05-19 14:05:41 +0100291 spin_unlock(&eurwdt_lock);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700292 /* Fall */
293
294 case WDIOC_GETTIMEOUT:
295 return put_user(eurwdt_timeout, p);
296
Wim Van Sebroeck0c060902008-07-18 11:41:17 +0000297 default:
298 return -ENOTTY;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700299 }
300}
301
302/**
303 * eurwdt_open:
304 * @inode: inode of device
305 * @file: file handle to device
306 *
307 * The misc device has been opened. The watchdog device is single
308 * open and on opening we load the counter.
309 */
310
311static int eurwdt_open(struct inode *inode, struct file *file)
312{
313 if (test_and_set_bit(0, &eurwdt_is_open))
314 return -EBUSY;
315 eurwdt_timeout = WDT_TIMEOUT; /* initial timeout */
316 /* Activate the WDT */
317 eurwdt_activate_timer();
318 return nonseekable_open(inode, file);
319}
320
321/**
322 * eurwdt_release:
323 * @inode: inode to board
324 * @file: file handle to board
325 *
326 * The watchdog has a configurable API. There is a religious dispute
327 * between people who want their watchdog to be able to shut down and
328 * those who want to be sure if the watchdog manager dies the machine
329 * reboots. In the former case we disable the counters, in the latter
330 * case you have to open it again very soon.
331 */
332
333static int eurwdt_release(struct inode *inode, struct file *file)
334{
Alan Cox89ea2422008-05-19 14:05:41 +0100335 if (eur_expect_close == 42)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700336 eurwdt_disable_timer();
Alan Cox89ea2422008-05-19 14:05:41 +0100337 else {
338 printk(KERN_CRIT
339 "eurwdt: Unexpected close, not stopping watchdog!\n");
Linus Torvalds1da177e2005-04-16 15:20:36 -0700340 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
359static int eurwdt_notify_sys(struct notifier_block *this, unsigned long code,
360 void *unused)
361{
Wim Van Sebroeck7944d3a2008-08-06 20:19:41 +0000362 if (code == SYS_DOWN || code == SYS_HALT)
363 eurwdt_disable_timer(); /* Turn the card off */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700364
365 return NOTIFY_DONE;
366}
367
368/*
369 * Kernel Interfaces
370 */
371
372
Arjan van de Ven62322d22006-07-03 00:24:21 -0700373static const struct file_operations eurwdt_fops = {
Alan Cox89ea2422008-05-19 14:05:41 +0100374 .owner = THIS_MODULE,
375 .llseek = no_llseek,
376 .write = eurwdt_write,
377 .unlocked_ioctl = eurwdt_ioctl,
378 .open = eurwdt_open,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700379 .release = eurwdt_release,
380};
381
382static 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
393static 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
407static 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
426static int __init eurwdt_init(void)
427{
428 int ret;
429
Yong Zhang86b59122011-09-07 16:10:55 +0800430 ret = request_irq(irq, eurwdt_interrupt, 0, "eurwdt", NULL);
Alan Cox89ea2422008-05-19 14:05:41 +0100431 if (ret) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700432 printk(KERN_ERR "eurwdt: IRQ %d is not free.\n", irq);
Alexey Dobriyanfb8f7ba2007-03-24 15:58:12 +0300433 goto out;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700434 }
435
436 if (!request_region(io, 2, "eurwdt")) {
437 printk(KERN_ERR "eurwdt: 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) {
Alan Cox89ea2422008-05-19 14:05:41 +0100444 printk(KERN_ERR
445 "eurwdt: can't register reboot notifier (err=%d)\n", ret);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700446 goto outreg;
447 }
448
Alexey Dobriyanfb8f7ba2007-03-24 15:58:12 +0300449 ret = misc_register(&eurwdt_miscdev);
450 if (ret) {
451 printk(KERN_ERR "eurwdt: can't misc_register on minor=%d\n",
452 WATCHDOG_MINOR);
453 goto outreboot;
454 }
455
Linus Torvalds1da177e2005-04-16 15:20:36 -0700456 eurwdt_unlock_chip();
457
458 ret = 0;
459 printk(KERN_INFO "Eurotech WDT driver 0.01 at %X (Interrupt %d)"
460 " - timeout event: %s\n",
461 io, irq, (!strcmp("int", ev) ? "int" : "reboot"));
462
463out:
464 return ret;
465
Alexey Dobriyanfb8f7ba2007-03-24 15:58:12 +0300466outreboot:
467 unregister_reboot_notifier(&eurwdt_notifier);
468
Linus Torvalds1da177e2005-04-16 15:20:36 -0700469outreg:
470 release_region(io, 2);
471
472outirq:
473 free_irq(irq, NULL);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700474 goto out;
475}
476
477module_init(eurwdt_init);
478module_exit(eurwdt_exit);
479
480MODULE_AUTHOR("Rodolfo Giometti");
481MODULE_DESCRIPTION("Driver for Eurotech CPU-1220/1410 on board watchdog");
482MODULE_LICENSE("GPL");
483MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR);