diff options
author | Linus Torvalds <torvalds@ppc970.osdl.org> | 2005-04-16 18:20:36 -0400 |
---|---|---|
committer | Linus Torvalds <torvalds@ppc970.osdl.org> | 2005-04-16 18:20:36 -0400 |
commit | 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 (patch) | |
tree | 0bba044c4ce775e45a88a51686b5d9f90697ea9d /drivers/char/watchdog/machzwd.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/machzwd.c')
-rw-r--r-- | drivers/char/watchdog/machzwd.c | 501 |
1 files changed, 501 insertions, 0 deletions
diff --git a/drivers/char/watchdog/machzwd.c b/drivers/char/watchdog/machzwd.c new file mode 100644 index 000000000000..9da395fa7794 --- /dev/null +++ b/drivers/char/watchdog/machzwd.c | |||
@@ -0,0 +1,501 @@ | |||
1 | /* | ||
2 | * MachZ ZF-Logic Watchdog Timer driver for Linux | ||
3 | * | ||
4 | * | ||
5 | * This program is free software; you can redistribute it and/or | ||
6 | * modify it under the terms of the GNU General Public License | ||
7 | * as published by the Free Software Foundation; either version | ||
8 | * 2 of the License, or (at your option) any later version. | ||
9 | * | ||
10 | * The author does NOT admit liability nor provide warranty for | ||
11 | * any of this software. This material is provided "AS-IS" in | ||
12 | * the hope that it may be useful for others. | ||
13 | * | ||
14 | * Author: Fernando Fuganti <fuganti@conectiva.com.br> | ||
15 | * | ||
16 | * Based on sbc60xxwdt.c by Jakob Oestergaard | ||
17 | * | ||
18 | * | ||
19 | * We have two timers (wd#1, wd#2) driven by a 32 KHz clock with the | ||
20 | * following periods: | ||
21 | * wd#1 - 2 seconds; | ||
22 | * wd#2 - 7.2 ms; | ||
23 | * After the expiration of wd#1, it can generate a NMI, SCI, SMI, or | ||
24 | * a system RESET and it starts wd#2 that unconditionaly will RESET | ||
25 | * the system when the counter reaches zero. | ||
26 | * | ||
27 | * 14-Dec-2001 Matt Domsch <Matt_Domsch@dell.com> | ||
28 | * Added nowayout module option to override CONFIG_WATCHDOG_NOWAYOUT | ||
29 | */ | ||
30 | |||
31 | #include <linux/config.h> | ||
32 | #include <linux/module.h> | ||
33 | #include <linux/moduleparam.h> | ||
34 | #include <linux/types.h> | ||
35 | #include <linux/timer.h> | ||
36 | #include <linux/jiffies.h> | ||
37 | #include <linux/miscdevice.h> | ||
38 | #include <linux/watchdog.h> | ||
39 | #include <linux/fs.h> | ||
40 | #include <linux/ioport.h> | ||
41 | #include <linux/notifier.h> | ||
42 | #include <linux/reboot.h> | ||
43 | #include <linux/init.h> | ||
44 | |||
45 | #include <asm/io.h> | ||
46 | #include <asm/uaccess.h> | ||
47 | #include <asm/system.h> | ||
48 | |||
49 | /* ports */ | ||
50 | #define ZF_IOBASE 0x218 | ||
51 | #define INDEX 0x218 | ||
52 | #define DATA_B 0x219 | ||
53 | #define DATA_W 0x21A | ||
54 | #define DATA_D 0x21A | ||
55 | |||
56 | /* indexes */ /* size */ | ||
57 | #define ZFL_VERSION 0x02 /* 16 */ | ||
58 | #define CONTROL 0x10 /* 16 */ | ||
59 | #define STATUS 0x12 /* 8 */ | ||
60 | #define COUNTER_1 0x0C /* 16 */ | ||
61 | #define COUNTER_2 0x0E /* 8 */ | ||
62 | #define PULSE_LEN 0x0F /* 8 */ | ||
63 | |||
64 | /* controls */ | ||
65 | #define ENABLE_WD1 0x0001 | ||
66 | #define ENABLE_WD2 0x0002 | ||
67 | #define RESET_WD1 0x0010 | ||
68 | #define RESET_WD2 0x0020 | ||
69 | #define GEN_SCI 0x0100 | ||
70 | #define GEN_NMI 0x0200 | ||
71 | #define GEN_SMI 0x0400 | ||
72 | #define GEN_RESET 0x0800 | ||
73 | |||
74 | |||
75 | /* utilities */ | ||
76 | |||
77 | #define WD1 0 | ||
78 | #define WD2 1 | ||
79 | |||
80 | #define zf_writew(port, data) { outb(port, INDEX); outw(data, DATA_W); } | ||
81 | #define zf_writeb(port, data) { outb(port, INDEX); outb(data, DATA_B); } | ||
82 | #define zf_get_ZFL_version() zf_readw(ZFL_VERSION) | ||
83 | |||
84 | |||
85 | static unsigned short zf_readw(unsigned char port) | ||
86 | { | ||
87 | outb(port, INDEX); | ||
88 | return inw(DATA_W); | ||
89 | } | ||
90 | |||
91 | |||
92 | MODULE_AUTHOR("Fernando Fuganti <fuganti@conectiva.com.br>"); | ||
93 | MODULE_DESCRIPTION("MachZ ZF-Logic Watchdog driver"); | ||
94 | MODULE_LICENSE("GPL"); | ||
95 | MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR); | ||
96 | |||
97 | #ifdef CONFIG_WATCHDOG_NOWAYOUT | ||
98 | static int nowayout = 1; | ||
99 | #else | ||
100 | static int nowayout = 0; | ||
101 | #endif | ||
102 | |||
103 | module_param(nowayout, int, 0); | ||
104 | MODULE_PARM_DESC(nowayout, "Watchdog cannot be stopped once started (default=CONFIG_WATCHDOG_NOWAYOUT)"); | ||
105 | |||
106 | #define PFX "machzwd" | ||
107 | |||
108 | static struct watchdog_info zf_info = { | ||
109 | .options = WDIOF_KEEPALIVEPING | WDIOF_MAGICCLOSE, | ||
110 | .firmware_version = 1, | ||
111 | .identity = "ZF-Logic watchdog", | ||
112 | }; | ||
113 | |||
114 | |||
115 | /* | ||
116 | * action refers to action taken when watchdog resets | ||
117 | * 0 = GEN_RESET | ||
118 | * 1 = GEN_SMI | ||
119 | * 2 = GEN_NMI | ||
120 | * 3 = GEN_SCI | ||
121 | * defaults to GEN_RESET (0) | ||
122 | */ | ||
123 | static int action = 0; | ||
124 | module_param(action, int, 0); | ||
125 | MODULE_PARM_DESC(action, "after watchdog resets, generate: 0 = RESET(*) 1 = SMI 2 = NMI 3 = SCI"); | ||
126 | |||
127 | static int zf_action = GEN_RESET; | ||
128 | static unsigned long zf_is_open; | ||
129 | static char zf_expect_close; | ||
130 | static spinlock_t zf_lock; | ||
131 | static spinlock_t zf_port_lock; | ||
132 | static struct timer_list zf_timer; | ||
133 | static unsigned long next_heartbeat = 0; | ||
134 | |||
135 | |||
136 | /* timeout for user land heart beat (10 seconds) */ | ||
137 | #define ZF_USER_TIMEO (HZ*10) | ||
138 | |||
139 | /* timeout for hardware watchdog (~500ms) */ | ||
140 | #define ZF_HW_TIMEO (HZ/2) | ||
141 | |||
142 | /* number of ticks on WD#1 (driven by a 32KHz clock, 2s) */ | ||
143 | #define ZF_CTIMEOUT 0xffff | ||
144 | |||
145 | #ifndef ZF_DEBUG | ||
146 | # define dprintk(format, args...) | ||
147 | #else | ||
148 | # define dprintk(format, args...) printk(KERN_DEBUG PFX ":%s:%d: " format, __FUNCTION__, __LINE__ , ## args) | ||
149 | #endif | ||
150 | |||
151 | |||
152 | static inline void zf_set_status(unsigned char new) | ||
153 | { | ||
154 | zf_writeb(STATUS, new); | ||
155 | } | ||
156 | |||
157 | |||
158 | /* CONTROL register functions */ | ||
159 | |||
160 | static inline unsigned short zf_get_control(void) | ||
161 | { | ||
162 | return zf_readw(CONTROL); | ||
163 | } | ||
164 | |||
165 | static inline void zf_set_control(unsigned short new) | ||
166 | { | ||
167 | zf_writew(CONTROL, new); | ||
168 | } | ||
169 | |||
170 | |||
171 | /* WD#? counter functions */ | ||
172 | /* | ||
173 | * Just set counter value | ||
174 | */ | ||
175 | |||
176 | static inline void zf_set_timer(unsigned short new, unsigned char n) | ||
177 | { | ||
178 | switch(n){ | ||
179 | case WD1: | ||
180 | zf_writew(COUNTER_1, new); | ||
181 | case WD2: | ||
182 | zf_writeb(COUNTER_2, new > 0xff ? 0xff : new); | ||
183 | default: | ||
184 | return; | ||
185 | } | ||
186 | } | ||
187 | |||
188 | /* | ||
189 | * stop hardware timer | ||
190 | */ | ||
191 | static void zf_timer_off(void) | ||
192 | { | ||
193 | unsigned int ctrl_reg = 0; | ||
194 | unsigned long flags; | ||
195 | |||
196 | /* stop internal ping */ | ||
197 | del_timer_sync(&zf_timer); | ||
198 | |||
199 | spin_lock_irqsave(&zf_port_lock, flags); | ||
200 | /* stop watchdog timer */ | ||
201 | ctrl_reg = zf_get_control(); | ||
202 | ctrl_reg |= (ENABLE_WD1|ENABLE_WD2); /* disable wd1 and wd2 */ | ||
203 | ctrl_reg &= ~(ENABLE_WD1|ENABLE_WD2); | ||
204 | zf_set_control(ctrl_reg); | ||
205 | spin_unlock_irqrestore(&zf_port_lock, flags); | ||
206 | |||
207 | printk(KERN_INFO PFX ": Watchdog timer is now disabled\n"); | ||
208 | } | ||
209 | |||
210 | |||
211 | /* | ||
212 | * start hardware timer | ||
213 | */ | ||
214 | static void zf_timer_on(void) | ||
215 | { | ||
216 | unsigned int ctrl_reg = 0; | ||
217 | unsigned long flags; | ||
218 | |||
219 | spin_lock_irqsave(&zf_port_lock, flags); | ||
220 | |||
221 | zf_writeb(PULSE_LEN, 0xff); | ||
222 | |||
223 | zf_set_timer(ZF_CTIMEOUT, WD1); | ||
224 | |||
225 | /* user land ping */ | ||
226 | next_heartbeat = jiffies + ZF_USER_TIMEO; | ||
227 | |||
228 | /* start the timer for internal ping */ | ||
229 | zf_timer.expires = jiffies + ZF_HW_TIMEO; | ||
230 | |||
231 | add_timer(&zf_timer); | ||
232 | |||
233 | /* start watchdog timer */ | ||
234 | ctrl_reg = zf_get_control(); | ||
235 | ctrl_reg |= (ENABLE_WD1|zf_action); | ||
236 | zf_set_control(ctrl_reg); | ||
237 | spin_unlock_irqrestore(&zf_port_lock, flags); | ||
238 | |||
239 | printk(KERN_INFO PFX ": Watchdog timer is now enabled\n"); | ||
240 | } | ||
241 | |||
242 | |||
243 | static void zf_ping(unsigned long data) | ||
244 | { | ||
245 | unsigned int ctrl_reg = 0; | ||
246 | unsigned long flags; | ||
247 | |||
248 | zf_writeb(COUNTER_2, 0xff); | ||
249 | |||
250 | if(time_before(jiffies, next_heartbeat)){ | ||
251 | |||
252 | dprintk("time_before: %ld\n", next_heartbeat - jiffies); | ||
253 | |||
254 | /* | ||
255 | * reset event is activated by transition from 0 to 1 on | ||
256 | * RESET_WD1 bit and we assume that it is already zero... | ||
257 | */ | ||
258 | |||
259 | spin_lock_irqsave(&zf_port_lock, flags); | ||
260 | ctrl_reg = zf_get_control(); | ||
261 | ctrl_reg |= RESET_WD1; | ||
262 | zf_set_control(ctrl_reg); | ||
263 | |||
264 | /* ...and nothing changes until here */ | ||
265 | ctrl_reg &= ~(RESET_WD1); | ||
266 | zf_set_control(ctrl_reg); | ||
267 | spin_unlock_irqrestore(&zf_port_lock, flags); | ||
268 | |||
269 | zf_timer.expires = jiffies + ZF_HW_TIMEO; | ||
270 | add_timer(&zf_timer); | ||
271 | }else{ | ||
272 | printk(KERN_CRIT PFX ": I will reset your machine\n"); | ||
273 | } | ||
274 | } | ||
275 | |||
276 | static ssize_t zf_write(struct file *file, const char __user *buf, size_t count, | ||
277 | loff_t *ppos) | ||
278 | { | ||
279 | /* See if we got the magic character */ | ||
280 | if(count){ | ||
281 | |||
282 | /* | ||
283 | * no need to check for close confirmation | ||
284 | * no way to disable watchdog ;) | ||
285 | */ | ||
286 | if (!nowayout) { | ||
287 | size_t ofs; | ||
288 | |||
289 | /* | ||
290 | * note: just in case someone wrote the magic character | ||
291 | * five months ago... | ||
292 | */ | ||
293 | zf_expect_close = 0; | ||
294 | |||
295 | /* now scan */ | ||
296 | for (ofs = 0; ofs != count; ofs++){ | ||
297 | char c; | ||
298 | if (get_user(c, buf + ofs)) | ||
299 | return -EFAULT; | ||
300 | if (c == 'V'){ | ||
301 | zf_expect_close = 42; | ||
302 | dprintk("zf_expect_close = 42\n"); | ||
303 | } | ||
304 | } | ||
305 | } | ||
306 | |||
307 | /* | ||
308 | * Well, anyhow someone wrote to us, | ||
309 | * we should return that favour | ||
310 | */ | ||
311 | next_heartbeat = jiffies + ZF_USER_TIMEO; | ||
312 | dprintk("user ping at %ld\n", jiffies); | ||
313 | |||
314 | } | ||
315 | |||
316 | return count; | ||
317 | } | ||
318 | |||
319 | static int zf_ioctl(struct inode *inode, struct file *file, unsigned int cmd, | ||
320 | unsigned long arg) | ||
321 | { | ||
322 | void __user *argp = (void __user *)arg; | ||
323 | int __user *p = argp; | ||
324 | switch(cmd){ | ||
325 | case WDIOC_GETSUPPORT: | ||
326 | if (copy_to_user(argp, &zf_info, sizeof(zf_info))) | ||
327 | return -EFAULT; | ||
328 | break; | ||
329 | |||
330 | case WDIOC_GETSTATUS: | ||
331 | return put_user(0, p); | ||
332 | |||
333 | case WDIOC_KEEPALIVE: | ||
334 | zf_ping(0); | ||
335 | break; | ||
336 | |||
337 | default: | ||
338 | return -ENOIOCTLCMD; | ||
339 | } | ||
340 | |||
341 | return 0; | ||
342 | } | ||
343 | |||
344 | static int zf_open(struct inode *inode, struct file *file) | ||
345 | { | ||
346 | spin_lock(&zf_lock); | ||
347 | if(test_and_set_bit(0, &zf_is_open)) { | ||
348 | spin_unlock(&zf_lock); | ||
349 | return -EBUSY; | ||
350 | } | ||
351 | |||
352 | if (nowayout) | ||
353 | __module_get(THIS_MODULE); | ||
354 | |||
355 | spin_unlock(&zf_lock); | ||
356 | |||
357 | zf_timer_on(); | ||
358 | |||
359 | return nonseekable_open(inode, file); | ||
360 | } | ||
361 | |||
362 | static int zf_close(struct inode *inode, struct file *file) | ||
363 | { | ||
364 | if(zf_expect_close == 42){ | ||
365 | zf_timer_off(); | ||
366 | } else { | ||
367 | del_timer(&zf_timer); | ||
368 | printk(KERN_ERR PFX ": device file closed unexpectedly. Will not stop the WDT!\n"); | ||
369 | } | ||
370 | |||
371 | spin_lock(&zf_lock); | ||
372 | clear_bit(0, &zf_is_open); | ||
373 | spin_unlock(&zf_lock); | ||
374 | |||
375 | zf_expect_close = 0; | ||
376 | |||
377 | return 0; | ||
378 | } | ||
379 | |||
380 | /* | ||
381 | * Notifier for system down | ||
382 | */ | ||
383 | |||
384 | static int zf_notify_sys(struct notifier_block *this, unsigned long code, | ||
385 | void *unused) | ||
386 | { | ||
387 | if(code == SYS_DOWN || code == SYS_HALT){ | ||
388 | zf_timer_off(); | ||
389 | } | ||
390 | |||
391 | return NOTIFY_DONE; | ||
392 | } | ||
393 | |||
394 | |||
395 | |||
396 | |||
397 | static struct file_operations zf_fops = { | ||
398 | .owner = THIS_MODULE, | ||
399 | .llseek = no_llseek, | ||
400 | .write = zf_write, | ||
401 | .ioctl = zf_ioctl, | ||
402 | .open = zf_open, | ||
403 | .release = zf_close, | ||
404 | }; | ||
405 | |||
406 | static struct miscdevice zf_miscdev = { | ||
407 | .minor = WATCHDOG_MINOR, | ||
408 | .name = "watchdog", | ||
409 | .fops = &zf_fops, | ||
410 | }; | ||
411 | |||
412 | |||
413 | /* | ||
414 | * The device needs to learn about soft shutdowns in order to | ||
415 | * turn the timebomb registers off. | ||
416 | */ | ||
417 | static struct notifier_block zf_notifier = { | ||
418 | .notifier_call = zf_notify_sys, | ||
419 | }; | ||
420 | |||
421 | static void __init zf_show_action(int act) | ||
422 | { | ||
423 | char *str[] = { "RESET", "SMI", "NMI", "SCI" }; | ||
424 | |||
425 | printk(KERN_INFO PFX ": Watchdog using action = %s\n", str[act]); | ||
426 | } | ||
427 | |||
428 | static int __init zf_init(void) | ||
429 | { | ||
430 | int ret; | ||
431 | |||
432 | printk(KERN_INFO PFX ": MachZ ZF-Logic Watchdog driver initializing.\n"); | ||
433 | |||
434 | ret = zf_get_ZFL_version(); | ||
435 | printk("%#x\n", ret); | ||
436 | if((!ret) || (ret != 0xffff)){ | ||
437 | printk(KERN_WARNING PFX ": no ZF-Logic found\n"); | ||
438 | return -ENODEV; | ||
439 | } | ||
440 | |||
441 | if((action <= 3) && (action >= 0)){ | ||
442 | zf_action = zf_action>>action; | ||
443 | } else | ||
444 | action = 0; | ||
445 | |||
446 | zf_show_action(action); | ||
447 | |||
448 | spin_lock_init(&zf_lock); | ||
449 | spin_lock_init(&zf_port_lock); | ||
450 | |||
451 | ret = misc_register(&zf_miscdev); | ||
452 | if (ret){ | ||
453 | printk(KERN_ERR "can't misc_register on minor=%d\n", | ||
454 | WATCHDOG_MINOR); | ||
455 | goto out; | ||
456 | } | ||
457 | |||
458 | if(!request_region(ZF_IOBASE, 3, "MachZ ZFL WDT")){ | ||
459 | printk(KERN_ERR "cannot reserve I/O ports at %d\n", | ||
460 | ZF_IOBASE); | ||
461 | ret = -EBUSY; | ||
462 | goto no_region; | ||
463 | } | ||
464 | |||
465 | ret = register_reboot_notifier(&zf_notifier); | ||
466 | if(ret){ | ||
467 | printk(KERN_ERR "can't register reboot notifier (err=%d)\n", | ||
468 | ret); | ||
469 | goto no_reboot; | ||
470 | } | ||
471 | |||
472 | zf_set_status(0); | ||
473 | zf_set_control(0); | ||
474 | |||
475 | /* this is the timer that will do the hard work */ | ||
476 | init_timer(&zf_timer); | ||
477 | zf_timer.function = zf_ping; | ||
478 | zf_timer.data = 0; | ||
479 | |||
480 | return 0; | ||
481 | |||
482 | no_reboot: | ||
483 | release_region(ZF_IOBASE, 3); | ||
484 | no_region: | ||
485 | misc_deregister(&zf_miscdev); | ||
486 | out: | ||
487 | return ret; | ||
488 | } | ||
489 | |||
490 | |||
491 | static void __exit zf_exit(void) | ||
492 | { | ||
493 | zf_timer_off(); | ||
494 | |||
495 | misc_deregister(&zf_miscdev); | ||
496 | unregister_reboot_notifier(&zf_notifier); | ||
497 | release_region(ZF_IOBASE, 3); | ||
498 | } | ||
499 | |||
500 | module_init(zf_init); | ||
501 | module_exit(zf_exit); | ||