aboutsummaryrefslogtreecommitdiffstats
path: root/drivers/char/watchdog/w83877f_wdt.c
diff options
context:
space:
mode:
Diffstat (limited to 'drivers/char/watchdog/w83877f_wdt.c')
-rw-r--r--drivers/char/watchdog/w83877f_wdt.c415
1 files changed, 0 insertions, 415 deletions
diff --git a/drivers/char/watchdog/w83877f_wdt.c b/drivers/char/watchdog/w83877f_wdt.c
deleted file mode 100644
index 3c88fe18f4f4..000000000000
--- a/drivers/char/watchdog/w83877f_wdt.c
+++ /dev/null
@@ -1,415 +0,0 @@
1/*
2 * W83877F Computer Watchdog Timer driver
3 *
4 * Based on acquirewdt.c by Alan Cox,
5 * and sbc60xxwdt.c by Jakob Oestergaard <jakob@unthought.net>
6 *
7 * This program is free software; you can redistribute it and/or
8 * modify it under the terms of the GNU General Public License
9 * as published by the Free Software Foundation; either version
10 * 2 of the License, or (at your option) any later version.
11 *
12 * The authors do NOT admit liability nor provide warranty for
13 * any of this software. This material is provided "AS-IS" in
14 * the hope that it may be useful for others.
15 *
16 * (c) Copyright 2001 Scott Jennings <linuxdrivers@oro.net>
17 *
18 * 4/19 - 2001 [Initial revision]
19 * 9/27 - 2001 Added spinlocking
20 * 4/12 - 2002 [rob@osinvestor.com] Eliminate extra comments
21 * Eliminate fop_read
22 * Eliminate extra spin_unlock
23 * Added KERN_* tags to printks
24 * add CONFIG_WATCHDOG_NOWAYOUT support
25 * fix possible wdt_is_open race
26 * changed watchdog_info to correctly reflect what the driver offers
27 * added WDIOC_GETSTATUS, WDIOC_GETBOOTSTATUS, WDIOC_SETTIMEOUT,
28 * WDIOC_GETTIMEOUT, and WDIOC_SETOPTIONS ioctls
29 * 09/8 - 2003 [wim@iguana.be] cleanup of trailing spaces
30 * added extra printk's for startup problems
31 * use module_param
32 * made timeout (the emulated heartbeat) a module_param
33 * made the keepalive ping an internal subroutine
34 *
35 * This WDT driver is different from most other Linux WDT
36 * drivers in that the driver will ping the watchdog by itself,
37 * because this particular WDT has a very short timeout (1.6
38 * seconds) and it would be insane to count on any userspace
39 * daemon always getting scheduled within that time frame.
40 */
41
42#include <linux/module.h>
43#include <linux/moduleparam.h>
44#include <linux/types.h>
45#include <linux/timer.h>
46#include <linux/jiffies.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#include <asm/io.h>
55#include <asm/uaccess.h>
56#include <asm/system.h>
57
58#define OUR_NAME "w83877f_wdt"
59#define PFX OUR_NAME ": "
60
61#define ENABLE_W83877F_PORT 0x3F0
62#define ENABLE_W83877F 0x87
63#define DISABLE_W83877F 0xAA
64#define WDT_PING 0x443
65#define WDT_REGISTER 0x14
66#define WDT_ENABLE 0x9C
67#define WDT_DISABLE 0x8C
68
69/*
70 * The W83877F seems to be fixed at 1.6s timeout (at least on the
71 * EMACS PC-104 board I'm using). If we reset the watchdog every
72 * ~250ms we should be safe. */
73
74#define WDT_INTERVAL (HZ/4+1)
75
76/*
77 * We must not require too good response from the userspace daemon.
78 * Here we require the userspace daemon to send us a heartbeat
79 * char to /dev/watchdog every 30 seconds.
80 */
81
82#define WATCHDOG_TIMEOUT 30 /* 30 sec default timeout */
83static int timeout = WATCHDOG_TIMEOUT; /* in seconds, will be multiplied by HZ to get seconds to wait for a ping */
84module_param(timeout, int, 0);
85MODULE_PARM_DESC(timeout, "Watchdog timeout in seconds. (1<=timeout<=3600, default=" __MODULE_STRING(WATCHDOG_TIMEOUT) ")");
86
87
88static int nowayout = WATCHDOG_NOWAYOUT;
89module_param(nowayout, int, 0);
90MODULE_PARM_DESC(nowayout, "Watchdog cannot be stopped once started (default=" __MODULE_STRING(WATCHDOG_NOWAYOUT) ")");
91
92static void wdt_timer_ping(unsigned long);
93static DEFINE_TIMER(timer, wdt_timer_ping, 0, 0);
94static unsigned long next_heartbeat;
95static unsigned long wdt_is_open;
96static char wdt_expect_close;
97static spinlock_t wdt_spinlock;
98
99/*
100 * Whack the dog
101 */
102
103static void wdt_timer_ping(unsigned long data)
104{
105 /* If we got a heartbeat pulse within the WDT_US_INTERVAL
106 * we agree to ping the WDT
107 */
108 if(time_before(jiffies, next_heartbeat))
109 {
110 /* Ping the WDT */
111 spin_lock(&wdt_spinlock);
112
113 /* Ping the WDT by reading from WDT_PING */
114 inb_p(WDT_PING);
115
116 /* Re-set the timer interval */
117 mod_timer(&timer, jiffies + WDT_INTERVAL);
118
119 spin_unlock(&wdt_spinlock);
120
121 } else {
122 printk(KERN_WARNING PFX "Heartbeat lost! Will not ping the watchdog\n");
123 }
124}
125
126/*
127 * Utility routines
128 */
129
130static void wdt_change(int writeval)
131{
132 unsigned long flags;
133 spin_lock_irqsave(&wdt_spinlock, flags);
134
135 /* buy some time */
136 inb_p(WDT_PING);
137
138 /* make W83877F available */
139 outb_p(ENABLE_W83877F, ENABLE_W83877F_PORT);
140 outb_p(ENABLE_W83877F, ENABLE_W83877F_PORT);
141
142 /* enable watchdog */
143 outb_p(WDT_REGISTER, ENABLE_W83877F_PORT);
144 outb_p(writeval, ENABLE_W83877F_PORT+1);
145
146 /* lock the W8387FF away */
147 outb_p(DISABLE_W83877F, ENABLE_W83877F_PORT);
148
149 spin_unlock_irqrestore(&wdt_spinlock, flags);
150}
151
152static void wdt_startup(void)
153{
154 next_heartbeat = jiffies + (timeout * HZ);
155
156 /* Start the timer */
157 mod_timer(&timer, jiffies + WDT_INTERVAL);
158
159 wdt_change(WDT_ENABLE);
160
161 printk(KERN_INFO PFX "Watchdog timer is now enabled.\n");
162}
163
164static void wdt_turnoff(void)
165{
166 /* Stop the timer */
167 del_timer(&timer);
168
169 wdt_change(WDT_DISABLE);
170
171 printk(KERN_INFO PFX "Watchdog timer is now disabled...\n");
172}
173
174static void wdt_keepalive(void)
175{
176 /* user land ping */
177 next_heartbeat = jiffies + (timeout * HZ);
178}
179
180/*
181 * /dev/watchdog handling
182 */
183
184static ssize_t fop_write(struct file * file, const char __user * buf, size_t count, loff_t * ppos)
185{
186 /* See if we got the magic character 'V' and reload the timer */
187 if(count)
188 {
189 if (!nowayout)
190 {
191 size_t ofs;
192
193 /* note: just in case someone wrote the magic character
194 * five months ago... */
195 wdt_expect_close = 0;
196
197 /* scan to see whether or not we got the magic character */
198 for(ofs = 0; ofs != count; ofs++)
199 {
200 char c;
201 if (get_user(c, buf + ofs))
202 return -EFAULT;
203 if (c == 'V')
204 wdt_expect_close = 42;
205 }
206 }
207
208 /* someone wrote to us, we should restart timer */
209 wdt_keepalive();
210 }
211 return count;
212}
213
214static int fop_open(struct inode * inode, struct file * file)
215{
216 /* Just in case we're already talking to someone... */
217 if(test_and_set_bit(0, &wdt_is_open))
218 return -EBUSY;
219
220 /* Good, fire up the show */
221 wdt_startup();
222 return nonseekable_open(inode, file);
223}
224
225static int fop_close(struct inode * inode, struct file * file)
226{
227 if(wdt_expect_close == 42)
228 wdt_turnoff();
229 else {
230 del_timer(&timer);
231 printk(KERN_CRIT PFX "device file closed unexpectedly. Will not stop the WDT!\n");
232 }
233 clear_bit(0, &wdt_is_open);
234 wdt_expect_close = 0;
235 return 0;
236}
237
238static int fop_ioctl(struct inode *inode, struct file *file, unsigned int cmd,
239 unsigned long arg)
240{
241 void __user *argp = (void __user *)arg;
242 int __user *p = argp;
243 static struct watchdog_info ident=
244 {
245 .options = WDIOF_KEEPALIVEPING | WDIOF_SETTIMEOUT | WDIOF_MAGICCLOSE,
246 .firmware_version = 1,
247 .identity = "W83877F",
248 };
249
250 switch(cmd)
251 {
252 default:
253 return -ENOTTY;
254 case WDIOC_GETSUPPORT:
255 return copy_to_user(argp, &ident, sizeof(ident))?-EFAULT:0;
256 case WDIOC_GETSTATUS:
257 case WDIOC_GETBOOTSTATUS:
258 return put_user(0, p);
259 case WDIOC_KEEPALIVE:
260 wdt_keepalive();
261 return 0;
262 case WDIOC_SETOPTIONS:
263 {
264 int new_options, retval = -EINVAL;
265
266 if(get_user(new_options, p))
267 return -EFAULT;
268
269 if(new_options & WDIOS_DISABLECARD) {
270 wdt_turnoff();
271 retval = 0;
272 }
273
274 if(new_options & WDIOS_ENABLECARD) {
275 wdt_startup();
276 retval = 0;
277 }
278
279 return retval;
280 }
281 case WDIOC_SETTIMEOUT:
282 {
283 int new_timeout;
284
285 if(get_user(new_timeout, p))
286 return -EFAULT;
287
288 if(new_timeout < 1 || new_timeout > 3600) /* arbitrary upper limit */
289 return -EINVAL;
290
291 timeout = new_timeout;
292 wdt_keepalive();
293 /* Fall through */
294 }
295 case WDIOC_GETTIMEOUT:
296 return put_user(timeout, p);
297 }
298}
299
300static const struct file_operations wdt_fops = {
301 .owner = THIS_MODULE,
302 .llseek = no_llseek,
303 .write = fop_write,
304 .open = fop_open,
305 .release = fop_close,
306 .ioctl = fop_ioctl,
307};
308
309static struct miscdevice wdt_miscdev = {
310 .minor = WATCHDOG_MINOR,
311 .name = "watchdog",
312 .fops = &wdt_fops,
313};
314
315/*
316 * Notifier for system down
317 */
318
319static int wdt_notify_sys(struct notifier_block *this, unsigned long code,
320 void *unused)
321{
322 if(code==SYS_DOWN || code==SYS_HALT)
323 wdt_turnoff();
324 return NOTIFY_DONE;
325}
326
327/*
328 * The WDT needs to learn about soft shutdowns in order to
329 * turn the timebomb registers off.
330 */
331
332static struct notifier_block wdt_notifier=
333{
334 .notifier_call = wdt_notify_sys,
335};
336
337static void __exit w83877f_wdt_unload(void)
338{
339 wdt_turnoff();
340
341 /* Deregister */
342 misc_deregister(&wdt_miscdev);
343
344 unregister_reboot_notifier(&wdt_notifier);
345 release_region(WDT_PING,1);
346 release_region(ENABLE_W83877F_PORT,2);
347}
348
349static int __init w83877f_wdt_init(void)
350{
351 int rc = -EBUSY;
352
353 spin_lock_init(&wdt_spinlock);
354
355 if(timeout < 1 || timeout > 3600) /* arbitrary upper limit */
356 {
357 timeout = WATCHDOG_TIMEOUT;
358 printk(KERN_INFO PFX "timeout value must be 1<=x<=3600, using %d\n",
359 timeout);
360 }
361
362 if (!request_region(ENABLE_W83877F_PORT, 2, "W83877F WDT"))
363 {
364 printk(KERN_ERR PFX "I/O address 0x%04x already in use\n",
365 ENABLE_W83877F_PORT);
366 rc = -EIO;
367 goto err_out;
368 }
369
370 if (!request_region(WDT_PING, 1, "W8387FF WDT"))
371 {
372 printk(KERN_ERR PFX "I/O address 0x%04x already in use\n",
373 WDT_PING);
374 rc = -EIO;
375 goto err_out_region1;
376 }
377
378 rc = misc_register(&wdt_miscdev);
379 if (rc)
380 {
381 printk(KERN_ERR PFX "cannot register miscdev on minor=%d (err=%d)\n",
382 wdt_miscdev.minor, rc);
383 goto err_out_region2;
384 }
385
386 rc = register_reboot_notifier(&wdt_notifier);
387 if (rc)
388 {
389 printk(KERN_ERR PFX "cannot register reboot notifier (err=%d)\n",
390 rc);
391 goto err_out_miscdev;
392 }
393
394 printk(KERN_INFO PFX "WDT driver for W83877F initialised. timeout=%d sec (nowayout=%d)\n",
395 timeout, nowayout);
396
397 return 0;
398
399err_out_miscdev:
400 misc_deregister(&wdt_miscdev);
401err_out_region2:
402 release_region(WDT_PING,1);
403err_out_region1:
404 release_region(ENABLE_W83877F_PORT,2);
405err_out:
406 return rc;
407}
408
409module_init(w83877f_wdt_init);
410module_exit(w83877f_wdt_unload);
411
412MODULE_AUTHOR("Scott and Bill Jennings");
413MODULE_DESCRIPTION("Driver for watchdog timer in w83877f chip");
414MODULE_LICENSE("GPL");
415MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR);
generated by cgit v1.2.2 (git 2.25.0) at 2024-12-18 11:17:50 -0500