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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/eurotechwdt.c
Linux-2.6.12-rc2v2.6.12-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/eurotechwdt.c')
-rw-r--r--drivers/char/watchdog/eurotechwdt.c474
1 files changed, 474 insertions, 0 deletions
diff --git a/drivers/char/watchdog/eurotechwdt.c b/drivers/char/watchdog/eurotechwdt.c
new file mode 100644
index 000000000000..d10e554a14d6
--- /dev/null
+++ b/drivers/char/watchdog/eurotechwdt.c
@@ -0,0 +1,474 @@
1/*
2 * Eurotech CPU-1220/1410 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@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 *
28 * 2002/04/25 - Rob Radez
29 * clean up #includes
30 * clean up locking
31 * make __setup param unique
32 * proper options in watchdog_info
33 * add WDIOC_GETSTATUS and WDIOC_SETOPTIONS ioctls
34 * add expect_close support
35 *
36 * 2001 - Rodolfo Giometti
37 * Initial release
38 *
39 * 2002.05.30 - Joel Becker <joel.becker@oracle.com>
40 * Added Matt Domsch's nowayout module option.
41 */
42
43#include <linux/config.h>
44#include <linux/interrupt.h>
45#include <linux/module.h>
46#include <linux/moduleparam.h>
47#include <linux/types.h>
48#include <linux/miscdevice.h>
49#include <linux/watchdog.h>
50#include <linux/fs.h>
51#include <linux/ioport.h>
52#include <linux/notifier.h>
53#include <linux/reboot.h>
54#include <linux/init.h>
55
56#include <asm/io.h>
57#include <asm/uaccess.h>
58#include <asm/system.h>
59
60static unsigned long eurwdt_is_open;
61static int eurwdt_timeout;
62static char eur_expect_close;
63
64/*
65 * You must set these - there is no sane way to probe for this board.
66 * You can use eurwdt=x,y to set these now.
67 */
68
69static int io = 0x3f0;
70static int irq = 10;
71static char *ev = "int";
72
73#define WDT_TIMEOUT 60 /* 1 minute */
74
75#ifdef CONFIG_WATCHDOG_NOWAYOUT
76static int nowayout = 1;
77#else
78static int nowayout = 0;
79#endif
80
81module_param(nowayout, int, 0);
82MODULE_PARM_DESC(nowayout, "Watchdog cannot be stopped once started (default=CONFIG_WATCHDOG_NOWAYOUT)");
83
84/*
85 * Some symbolic names
86 */
87
88#define WDT_CTRL_REG 0x30
89#define WDT_OUTPIN_CFG 0xe2
90#define WDT_EVENT_INT 0x00
91#define WDT_EVENT_REBOOT 0x08
92#define WDT_UNIT_SEL 0xf1
93#define WDT_UNIT_SECS 0x80
94#define WDT_TIMEOUT_VAL 0xf2
95#define WDT_TIMER_CFG 0xf3
96
97
98module_param(io, int, 0);
99MODULE_PARM_DESC(io, "Eurotech WDT io port (default=0x3f0)");
100module_param(irq, int, 0);
101MODULE_PARM_DESC(irq, "Eurotech WDT irq (default=10)");
102module_param(ev, charp, 0);
103MODULE_PARM_DESC(ev, "Eurotech WDT event type (default is `int')");
104
105
106/*
107 * Programming support
108 */
109
110static inline void eurwdt_write_reg(u8 index, u8 data)
111{
112 outb(index, io);
113 outb(data, io+1);
114}
115
116static inline void eurwdt_lock_chip(void)
117{
118 outb(0xaa, io);
119}
120
121static inline void eurwdt_unlock_chip(void)
122{
123 outb(0x55, io);
124 eurwdt_write_reg(0x07, 0x08); /* set the logical device */
125}
126
127static inline void eurwdt_set_timeout(int timeout)
128{
129 eurwdt_write_reg(WDT_TIMEOUT_VAL, (u8) timeout);
130}
131
132static inline void eurwdt_disable_timer(void)
133{
134 eurwdt_set_timeout(0);
135}
136
137static void eurwdt_activate_timer(void)
138{
139 eurwdt_disable_timer();
140 eurwdt_write_reg(WDT_CTRL_REG, 0x01); /* activate the WDT */
141 eurwdt_write_reg(WDT_OUTPIN_CFG, !strcmp("int", ev) ? WDT_EVENT_INT : WDT_EVENT_REBOOT);
142
143 /* Setting interrupt line */
144 if (irq == 2 || irq > 15 || irq < 0) {
145 printk(KERN_ERR ": invalid irq number\n");
146 irq = 0; /* if invalid we disable interrupt */
147 }
148 if (irq == 0)
149 printk(KERN_INFO ": interrupt disabled\n");
150
151 eurwdt_write_reg(WDT_TIMER_CFG, irq<<4);
152
153 eurwdt_write_reg(WDT_UNIT_SEL, WDT_UNIT_SECS); /* we use seconds */
154 eurwdt_set_timeout(0); /* the default timeout */
155}
156
157
158/*
159 * Kernel methods.
160 */
161
162static irqreturn_t eurwdt_interrupt(int irq, void *dev_id, struct pt_regs *regs)
163{
164 printk(KERN_CRIT "timeout WDT timeout\n");
165
166#ifdef ONLY_TESTING
167 printk(KERN_CRIT "Would Reboot.\n");
168#else
169 printk(KERN_CRIT "Initiating system reboot.\n");
170 machine_restart(NULL);
171#endif
172 return IRQ_HANDLED;
173}
174
175
176/**
177 * eurwdt_ping:
178 *
179 * Reload counter one with the watchdog timeout.
180 */
181
182static void eurwdt_ping(void)
183{
184 /* Write the watchdog default value */
185 eurwdt_set_timeout(eurwdt_timeout);
186}
187
188/**
189 * eurwdt_write:
190 * @file: file handle to the watchdog
191 * @buf: buffer to write (unused as data does not matter here
192 * @count: count of bytes
193 * @ppos: pointer to the position to write. No seeks allowed
194 *
195 * A write to a watchdog device is defined as a keepalive signal. Any
196 * write of data will do, as we we don't define content meaning.
197 */
198
199static ssize_t eurwdt_write(struct file *file, const char __user *buf,
200size_t count, loff_t *ppos)
201{
202 if (count) {
203 if (!nowayout) {
204 size_t i;
205
206 eur_expect_close = 0;
207
208 for (i = 0; i != count; i++) {
209 char c;
210 if(get_user(c, buf+i))
211 return -EFAULT;
212 if (c == 'V')
213 eur_expect_close = 42;
214 }
215 }
216 eurwdt_ping(); /* the default timeout */
217 }
218
219 return count;
220}
221
222/**
223 * eurwdt_ioctl:
224 * @inode: inode of the device
225 * @file: file handle to the device
226 * @cmd: watchdog command
227 * @arg: argument pointer
228 *
229 * The watchdog API defines a common set of functions for all watchdogs
230 * according to their available features.
231 */
232
233static int eurwdt_ioctl(struct inode *inode, struct file *file,
234 unsigned int cmd, unsigned long arg)
235{
236 void __user *argp = (void __user *)arg;
237 int __user *p = argp;
238 static struct watchdog_info ident = {
239 .options = WDIOF_KEEPALIVEPING | WDIOF_SETTIMEOUT | WDIOF_MAGICCLOSE,
240 .firmware_version = 1,
241 .identity = "WDT Eurotech CPU-1220/1410",
242 };
243
244 int time;
245 int options, retval = -EINVAL;
246
247 switch(cmd) {
248 default:
249 return -ENOIOCTLCMD;
250
251 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
258 case WDIOC_KEEPALIVE:
259 eurwdt_ping();
260 return 0;
261
262 case WDIOC_SETTIMEOUT:
263 if (copy_from_user(&time, p, sizeof(int)))
264 return -EFAULT;
265
266 /* Sanity check */
267 if (time < 0 || time > 255)
268 return -EINVAL;
269
270 eurwdt_timeout = time;
271 eurwdt_set_timeout(time);
272 /* Fall */
273
274 case WDIOC_GETTIMEOUT:
275 return put_user(eurwdt_timeout, p);
276
277 case WDIOC_SETOPTIONS:
278 if (get_user(options, p))
279 return -EFAULT;
280 if (options & WDIOS_DISABLECARD) {
281 eurwdt_disable_timer();
282 retval = 0;
283 }
284 if (options & WDIOS_ENABLECARD) {
285 eurwdt_activate_timer();
286 eurwdt_ping();
287 retval = 0;
288 }
289 return retval;
290 }
291}
292
293/**
294 * eurwdt_open:
295 * @inode: inode of device
296 * @file: file handle to device
297 *
298 * The misc device has been opened. The watchdog device is single
299 * open and on opening we load the counter.
300 */
301
302static int eurwdt_open(struct inode *inode, struct file *file)
303{
304 if (test_and_set_bit(0, &eurwdt_is_open))
305 return -EBUSY;
306 eurwdt_timeout = WDT_TIMEOUT; /* initial timeout */
307 /* Activate the WDT */
308 eurwdt_activate_timer();
309 return nonseekable_open(inode, file);
310}
311
312/**
313 * eurwdt_release:
314 * @inode: inode to board
315 * @file: file handle to board
316 *
317 * The watchdog has a configurable API. There is a religious dispute
318 * between people who want their watchdog to be able to shut down and
319 * those who want to be sure if the watchdog manager dies the machine
320 * reboots. In the former case we disable the counters, in the latter
321 * case you have to open it again very soon.
322 */
323
324static int eurwdt_release(struct inode *inode, struct file *file)
325{
326 if (eur_expect_close == 42) {
327 eurwdt_disable_timer();
328 } else {
329 printk(KERN_CRIT "eurwdt: Unexpected close, not stopping watchdog!\n");
330 eurwdt_ping();
331 }
332 clear_bit(0, &eurwdt_is_open);
333 eur_expect_close = 0;
334 return 0;
335}
336
337/**
338 * eurwdt_notify_sys:
339 * @this: our notifier block
340 * @code: the event being reported
341 * @unused: unused
342 *
343 * Our notifier is called on system shutdowns. We want to turn the card
344 * off at reboot otherwise the machine will reboot again during memory
345 * test or worse yet during the following fsck. This would suck, in fact
346 * trust me - if it happens it does suck.
347 */
348
349static int eurwdt_notify_sys(struct notifier_block *this, unsigned long code,
350 void *unused)
351{
352 if (code == SYS_DOWN || code == SYS_HALT) {
353 /* Turn the card off */
354 eurwdt_disable_timer();
355 }
356
357 return NOTIFY_DONE;
358}
359
360/*
361 * Kernel Interfaces
362 */
363
364
365static struct file_operations eurwdt_fops = {
366 .owner = THIS_MODULE,
367 .llseek = no_llseek,
368 .write = eurwdt_write,
369 .ioctl = eurwdt_ioctl,
370 .open = eurwdt_open,
371 .release = eurwdt_release,
372};
373
374static struct miscdevice eurwdt_miscdev = {
375 .minor = WATCHDOG_MINOR,
376 .name = "watchdog",
377 .fops = &eurwdt_fops,
378};
379
380/*
381 * The WDT card needs to learn about soft shutdowns in order to
382 * turn the timebomb registers off.
383 */
384
385static struct notifier_block eurwdt_notifier = {
386 .notifier_call = eurwdt_notify_sys,
387};
388
389/**
390 * cleanup_module:
391 *
392 * Unload the watchdog. You cannot do this with any file handles open.
393 * If your watchdog is set to continue ticking on close and you unload
394 * it, well it keeps ticking. We won't get the interrupt but the board
395 * will not touch PC memory so all is fine. You just have to load a new
396 * module in 60 seconds or reboot.
397 */
398
399static void __exit eurwdt_exit(void)
400{
401 eurwdt_lock_chip();
402
403 misc_deregister(&eurwdt_miscdev);
404
405 unregister_reboot_notifier(&eurwdt_notifier);
406 release_region(io, 2);
407 free_irq(irq, NULL);
408}
409
410/**
411 * eurwdt_init:
412 *
413 * Set up the WDT watchdog board. After grabbing the resources
414 * we require we need also to unlock the device.
415 * The open() function will actually kick the board off.
416 */
417
418static int __init eurwdt_init(void)
419{
420 int ret;
421
422 ret = misc_register(&eurwdt_miscdev);
423 if (ret) {
424 printk(KERN_ERR "eurwdt: can't misc_register on minor=%d\n",
425 WATCHDOG_MINOR);
426 goto out;
427 }
428
429 ret = request_irq(irq, eurwdt_interrupt, SA_INTERRUPT, "eurwdt", NULL);
430 if(ret) {
431 printk(KERN_ERR "eurwdt: IRQ %d is not free.\n", irq);
432 goto outmisc;
433 }
434
435 if (!request_region(io, 2, "eurwdt")) {
436 printk(KERN_ERR "eurwdt: IO %X is not free.\n", io);
437 ret = -EBUSY;
438 goto outirq;
439 }
440
441 ret = register_reboot_notifier(&eurwdt_notifier);
442 if (ret) {
443 printk(KERN_ERR "eurwdt: can't register reboot notifier (err=%d)\n", ret);
444 goto outreg;
445 }
446
447 eurwdt_unlock_chip();
448
449 ret = 0;
450 printk(KERN_INFO "Eurotech WDT driver 0.01 at %X (Interrupt %d)"
451 " - timeout event: %s\n",
452 io, irq, (!strcmp("int", ev) ? "int" : "reboot"));
453
454out:
455 return ret;
456
457outreg:
458 release_region(io, 2);
459
460outirq:
461 free_irq(irq, NULL);
462
463outmisc:
464 misc_deregister(&eurwdt_miscdev);
465 goto out;
466}
467
468module_init(eurwdt_init);
469module_exit(eurwdt_exit);
470
471MODULE_AUTHOR("Rodolfo Giometti");
472MODULE_DESCRIPTION("Driver for Eurotech CPU-1220/1410 on board watchdog");
473MODULE_LICENSE("GPL");
474MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR);