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authorLinus Torvalds <torvalds@ppc970.osdl.org>2005-04-16 18:20:36 -0400
committerLinus Torvalds <torvalds@ppc970.osdl.org>2005-04-16 18:20:36 -0400
commit1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 (patch)
tree0bba044c4ce775e45a88a51686b5d9f90697ea9d /drivers/char/watchdog/wdt977.c
Linux-2.6.12-rc2
Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
Diffstat (limited to 'drivers/char/watchdog/wdt977.c')
-rw-r--r--drivers/char/watchdog/wdt977.c459
1 files changed, 459 insertions, 0 deletions
diff --git a/drivers/char/watchdog/wdt977.c b/drivers/char/watchdog/wdt977.c
new file mode 100644
index 000000000000..072e9b214759
--- /dev/null
+++ b/drivers/char/watchdog/wdt977.c
@@ -0,0 +1,459 @@
1/*
2 * Wdt977 0.03: A Watchdog Device for Netwinder W83977AF chip
3 *
4 * (c) Copyright 1998 Rebel.com (Woody Suwalski <woody@netwinder.org>)
5 *
6 * -----------------------
7 *
8 * This program is free software; you can redistribute it and/or
9 * modify it under the terms of the GNU General Public License
10 * as published by the Free Software Foundation; either version
11 * 2 of the License, or (at your option) any later version.
12 *
13 * -----------------------
14 * 14-Dec-2001 Matt Domsch <Matt_Domsch@dell.com>
15 * Added nowayout module option to override CONFIG_WATCHDOG_NOWAYOUT
16 * 19-Dec-2001 Woody Suwalski: Netwinder fixes, ioctl interface
17 * 06-Jan-2002 Woody Suwalski: For compatibility, convert all timeouts
18 * from minutes to seconds.
19 * 07-Jul-2003 Daniele Bellucci: Audit return code of misc_register in
20 * nwwatchdog_init.
21 */
22
23#include <linux/module.h>
24#include <linux/moduleparam.h>
25#include <linux/config.h>
26#include <linux/types.h>
27#include <linux/kernel.h>
28#include <linux/fs.h>
29#include <linux/miscdevice.h>
30#include <linux/init.h>
31#include <linux/watchdog.h>
32#include <linux/notifier.h>
33#include <linux/reboot.h>
34
35#include <asm/io.h>
36#include <asm/system.h>
37#include <asm/mach-types.h>
38#include <asm/uaccess.h>
39
40#define PFX "Wdt977: "
41#define WATCHDOG_MINOR 130
42
43#define DEFAULT_TIMEOUT 60 /* default timeout in seconds */
44
45static int timeout = DEFAULT_TIMEOUT;
46static int timeoutM; /* timeout in minutes */
47static unsigned long timer_alive;
48static int testmode;
49static char expect_close;
50
51module_param(timeout, int, 0);
52MODULE_PARM_DESC(timeout,"Watchdog timeout in seconds (60..15300), default=" __MODULE_STRING(DEFAULT_TIMEOUT) ")");
53module_param(testmode, int, 0);
54MODULE_PARM_DESC(testmode,"Watchdog testmode (1 = no reboot), default=0");
55
56#ifdef CONFIG_WATCHDOG_NOWAYOUT
57static int nowayout = 1;
58#else
59static int nowayout = 0;
60#endif
61
62module_param(nowayout, int, 0);
63MODULE_PARM_DESC(nowayout, "Watchdog cannot be stopped once started (default=CONFIG_WATCHDOG_NOWAYOUT)");
64
65/*
66 * Start the watchdog
67 */
68
69static int wdt977_start(void)
70{
71 /* unlock the SuperIO chip */
72 outb(0x87,0x370);
73 outb(0x87,0x370);
74
75 /* select device Aux2 (device=8) and set watchdog regs F2, F3 and F4
76 * F2 has the timeout in minutes
77 * F3 could be set to the POWER LED blink (with GP17 set to PowerLed)
78 * at timeout, and to reset timer on kbd/mouse activity (not impl.)
79 * F4 is used to just clear the TIMEOUT'ed state (bit 0)
80 */
81 outb(0x07,0x370);
82 outb(0x08,0x371);
83 outb(0xF2,0x370);
84 outb(timeoutM,0x371);
85 outb(0xF3,0x370);
86 outb(0x00,0x371); /* another setting is 0E for kbd/mouse/LED */
87 outb(0xF4,0x370);
88 outb(0x00,0x371);
89
90 /* at last select device Aux1 (dev=7) and set GP16 as a watchdog output */
91 /* in test mode watch the bit 1 on F4 to indicate "triggered" */
92 if (!testmode)
93 {
94 outb(0x07,0x370);
95 outb(0x07,0x371);
96 outb(0xE6,0x370);
97 outb(0x08,0x371);
98 }
99
100 /* lock the SuperIO chip */
101 outb(0xAA,0x370);
102
103 printk(KERN_INFO PFX "activated.\n");
104
105 return 0;
106}
107
108/*
109 * Stop the watchdog
110 */
111
112static int wdt977_stop(void)
113{
114 /* unlock the SuperIO chip */
115 outb(0x87,0x370);
116 outb(0x87,0x370);
117
118 /* select device Aux2 (device=8) and set watchdog regs F2,F3 and F4
119 * F3 is reset to its default state
120 * F4 can clear the TIMEOUT'ed state (bit 0) - back to default
121 * We can not use GP17 as a PowerLed, as we use its usage as a RedLed
122 */
123 outb(0x07,0x370);
124 outb(0x08,0x371);
125 outb(0xF2,0x370);
126 outb(0xFF,0x371);
127 outb(0xF3,0x370);
128 outb(0x00,0x371);
129 outb(0xF4,0x370);
130 outb(0x00,0x371);
131 outb(0xF2,0x370);
132 outb(0x00,0x371);
133
134 /* at last select device Aux1 (dev=7) and set GP16 as a watchdog output */
135 outb(0x07,0x370);
136 outb(0x07,0x371);
137 outb(0xE6,0x370);
138 outb(0x08,0x371);
139
140 /* lock the SuperIO chip */
141 outb(0xAA,0x370);
142
143 printk(KERN_INFO PFX "shutdown.\n");
144
145 return 0;
146}
147
148/*
149 * Send a keepalive ping to the watchdog
150 * This is done by simply re-writing the timeout to reg. 0xF2
151 */
152
153static int wdt977_keepalive(void)
154{
155 /* unlock the SuperIO chip */
156 outb(0x87,0x370);
157 outb(0x87,0x370);
158
159 /* select device Aux2 (device=8) and kicks watchdog reg F2 */
160 /* F2 has the timeout in minutes */
161 outb(0x07,0x370);
162 outb(0x08,0x371);
163 outb(0xF2,0x370);
164 outb(timeoutM,0x371);
165
166 /* lock the SuperIO chip */
167 outb(0xAA,0x370);
168
169 return 0;
170}
171
172/*
173 * Set the watchdog timeout value
174 */
175
176static int wdt977_set_timeout(int t)
177{
178 int tmrval;
179
180 /* convert seconds to minutes, rounding up */
181 tmrval = (t + 59) / 60;
182
183 if (machine_is_netwinder()) {
184 /* we have a hw bug somewhere, so each 977 minute is actually only 30sec
185 * this limits the max timeout to half of device max of 255 minutes...
186 */
187 tmrval += tmrval;
188 }
189
190 if ((tmrval < 1) || (tmrval > 255))
191 return -EINVAL;
192
193 /* timeout is the timeout in seconds, timeoutM is the timeout in minutes) */
194 timeout = t;
195 timeoutM = tmrval;
196 return 0;
197}
198
199/*
200 * Get the watchdog status
201 */
202
203static int wdt977_get_status(int *status)
204{
205 int new_status;
206
207 *status=0;
208
209 /* unlock the SuperIO chip */
210 outb(0x87,0x370);
211 outb(0x87,0x370);
212
213 /* select device Aux2 (device=8) and read watchdog reg F4 */
214 outb(0x07,0x370);
215 outb(0x08,0x371);
216 outb(0xF4,0x370);
217 new_status = inb(0x371);
218
219 /* lock the SuperIO chip */
220 outb(0xAA,0x370);
221
222 if (new_status & 1)
223 *status |= WDIOF_CARDRESET;
224
225 return 0;
226}
227
228
229/*
230 * /dev/watchdog handling
231 */
232
233static int wdt977_open(struct inode *inode, struct file *file)
234{
235 /* If the watchdog is alive we don't need to start it again */
236 if( test_and_set_bit(0,&timer_alive) )
237 return -EBUSY;
238
239 if (nowayout)
240 __module_get(THIS_MODULE);
241
242 wdt977_start();
243 return nonseekable_open(inode, file);
244}
245
246static int wdt977_release(struct inode *inode, struct file *file)
247{
248 /*
249 * Shut off the timer.
250 * Lock it in if it's a module and we set nowayout
251 */
252 if (expect_close == 42)
253 {
254 wdt977_stop();
255 clear_bit(0,&timer_alive);
256 } else {
257 printk(KERN_CRIT PFX "Unexpected close, not stopping watchdog!\n");
258 wdt977_keepalive();
259 }
260 expect_close = 0;
261 return 0;
262}
263
264
265/*
266 * wdt977_write:
267 * @file: file handle to the watchdog
268 * @buf: buffer to write (unused as data does not matter here
269 * @count: count of bytes
270 * @ppos: pointer to the position to write. No seeks allowed
271 *
272 * A write to a watchdog device is defined as a keepalive signal. Any
273 * write of data will do, as we we don't define content meaning.
274 */
275
276static ssize_t wdt977_write(struct file *file, const char __user *buf,
277 size_t count, loff_t *ppos)
278{
279 if (count) {
280 if (!nowayout) {
281 size_t i;
282
283 /* In case it was set long ago */
284 expect_close = 0;
285
286 for (i = 0; i != count; i++) {
287 char c;
288 if (get_user(c, buf + i))
289 return -EFAULT;
290 if (c == 'V')
291 expect_close = 42;
292 }
293 }
294
295 wdt977_keepalive();
296 }
297 return count;
298}
299
300/*
301 * wdt977_ioctl:
302 * @inode: inode of the device
303 * @file: file handle to the device
304 * @cmd: watchdog command
305 * @arg: argument pointer
306 *
307 * The watchdog API defines a common set of functions for all watchdogs
308 * according to their available features.
309 */
310
311static struct watchdog_info ident = {
312 .options = WDIOF_SETTIMEOUT |
313 WDIOF_MAGICCLOSE |
314 WDIOF_KEEPALIVEPING,
315 .firmware_version = 1,
316 .identity = "Winbond 83977",
317};
318
319static int wdt977_ioctl(struct inode *inode, struct file *file,
320 unsigned int cmd, unsigned long arg)
321{
322 int status;
323 int new_options, retval = -EINVAL;
324 int new_timeout;
325 union {
326 struct watchdog_info __user *ident;
327 int __user *i;
328 } uarg;
329
330 uarg.i = (int __user *)arg;
331
332 switch(cmd)
333 {
334 default:
335 return -ENOIOCTLCMD;
336
337 case WDIOC_GETSUPPORT:
338 return copy_to_user(uarg.ident, &ident,
339 sizeof(ident)) ? -EFAULT : 0;
340
341 case WDIOC_GETSTATUS:
342 wdt977_get_status(&status);
343 return put_user(status, uarg.i);
344
345 case WDIOC_GETBOOTSTATUS:
346 return put_user(0, uarg.i);
347
348 case WDIOC_KEEPALIVE:
349 wdt977_keepalive();
350 return 0;
351
352 case WDIOC_SETOPTIONS:
353 if (get_user (new_options, uarg.i))
354 return -EFAULT;
355
356 if (new_options & WDIOS_DISABLECARD) {
357 wdt977_stop();
358 retval = 0;
359 }
360
361 if (new_options & WDIOS_ENABLECARD) {
362 wdt977_start();
363 retval = 0;
364 }
365
366 return retval;
367
368 case WDIOC_SETTIMEOUT:
369 if (get_user(new_timeout, uarg.i))
370 return -EFAULT;
371
372 if (wdt977_set_timeout(new_timeout))
373 return -EINVAL;
374
375 wdt977_keepalive();
376 /* Fall */
377
378 case WDIOC_GETTIMEOUT:
379 return put_user(timeout, uarg.i);
380
381 }
382}
383
384static int wdt977_notify_sys(struct notifier_block *this, unsigned long code,
385 void *unused)
386{
387 if(code==SYS_DOWN || code==SYS_HALT)
388 wdt977_stop();
389 return NOTIFY_DONE;
390}
391
392static struct file_operations wdt977_fops=
393{
394 .owner = THIS_MODULE,
395 .llseek = no_llseek,
396 .write = wdt977_write,
397 .ioctl = wdt977_ioctl,
398 .open = wdt977_open,
399 .release = wdt977_release,
400};
401
402static struct miscdevice wdt977_miscdev=
403{
404 .minor = WATCHDOG_MINOR,
405 .name = "watchdog",
406 .fops = &wdt977_fops,
407};
408
409static struct notifier_block wdt977_notifier = {
410 .notifier_call = wdt977_notify_sys,
411};
412
413static int __init nwwatchdog_init(void)
414{
415 int retval;
416 if (!machine_is_netwinder())
417 return -ENODEV;
418
419 /* Check that the timeout value is within it's range ; if not reset to the default */
420 if (wdt977_set_timeout(timeout)) {
421 wdt977_set_timeout(DEFAULT_TIMEOUT);
422 printk(KERN_INFO PFX "timeout value must be 60<timeout<15300, using %d\n",
423 DEFAULT_TIMEOUT);
424 }
425
426 retval = register_reboot_notifier(&wdt977_notifier);
427 if (retval) {
428 printk(KERN_ERR PFX "cannot register reboot notifier (err=%d)\n",
429 retval);
430 return retval;
431 }
432
433 retval = misc_register(&wdt977_miscdev);
434 if (retval) {
435 printk(KERN_ERR PFX "cannot register miscdev on minor=%d (err=%d)\n",
436 WATCHDOG_MINOR, retval);
437 unregister_reboot_notifier(&wdt977_notifier);
438 return retval;
439 }
440
441 printk(KERN_INFO PFX "initialized. timeout=%d sec (nowayout=%d, testmode = %i)\n",
442 timeout, nowayout, testmode);
443
444 return 0;
445}
446
447static void __exit nwwatchdog_exit(void)
448{
449 misc_deregister(&wdt977_miscdev);
450 unregister_reboot_notifier(&wdt977_notifier);
451}
452
453module_init(nwwatchdog_init);
454module_exit(nwwatchdog_exit);
455
456MODULE_AUTHOR("Woody Suwalski <woody@netwinder.org>");
457MODULE_DESCRIPTION("W83977AF Watchdog driver");
458MODULE_LICENSE("GPL");
459MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR);