Commit | Line | Data |
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1da177e4 LT |
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 | ||
1da177e4 LT |
31 | #include <linux/module.h> |
32 | #include <linux/moduleparam.h> | |
33 | #include <linux/types.h> | |
34 | #include <linux/timer.h> | |
35 | #include <linux/jiffies.h> | |
36 | #include <linux/miscdevice.h> | |
37 | #include <linux/watchdog.h> | |
38 | #include <linux/fs.h> | |
39 | #include <linux/ioport.h> | |
40 | #include <linux/notifier.h> | |
41 | #include <linux/reboot.h> | |
42 | #include <linux/init.h> | |
325ea4d3 AC |
43 | #include <linux/io.h> |
44 | #include <linux/uaccess.h> | |
1da177e4 | 45 | |
1da177e4 LT |
46 | #include <asm/system.h> |
47 | ||
48 | /* ports */ | |
49 | #define ZF_IOBASE 0x218 | |
50 | #define INDEX 0x218 | |
51 | #define DATA_B 0x219 | |
52 | #define DATA_W 0x21A | |
53 | #define DATA_D 0x21A | |
54 | ||
55 | /* indexes */ /* size */ | |
56 | #define ZFL_VERSION 0x02 /* 16 */ | |
57 | #define CONTROL 0x10 /* 16 */ | |
58 | #define STATUS 0x12 /* 8 */ | |
59 | #define COUNTER_1 0x0C /* 16 */ | |
60 | #define COUNTER_2 0x0E /* 8 */ | |
61 | #define PULSE_LEN 0x0F /* 8 */ | |
62 | ||
63 | /* controls */ | |
64 | #define ENABLE_WD1 0x0001 | |
65 | #define ENABLE_WD2 0x0002 | |
66 | #define RESET_WD1 0x0010 | |
67 | #define RESET_WD2 0x0020 | |
68 | #define GEN_SCI 0x0100 | |
69 | #define GEN_NMI 0x0200 | |
70 | #define GEN_SMI 0x0400 | |
71 | #define GEN_RESET 0x0800 | |
72 | ||
73 | ||
74 | /* utilities */ | |
75 | ||
76 | #define WD1 0 | |
77 | #define WD2 1 | |
78 | ||
79 | #define zf_writew(port, data) { outb(port, INDEX); outw(data, DATA_W); } | |
80 | #define zf_writeb(port, data) { outb(port, INDEX); outb(data, DATA_B); } | |
81 | #define zf_get_ZFL_version() zf_readw(ZFL_VERSION) | |
82 | ||
83 | ||
84 | static unsigned short zf_readw(unsigned char port) | |
85 | { | |
86 | outb(port, INDEX); | |
87 | return inw(DATA_W); | |
88 | } | |
89 | ||
90 | ||
91 | MODULE_AUTHOR("Fernando Fuganti <fuganti@conectiva.com.br>"); | |
92 | MODULE_DESCRIPTION("MachZ ZF-Logic Watchdog driver"); | |
93 | MODULE_LICENSE("GPL"); | |
94 | MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR); | |
95 | ||
4bfdf378 | 96 | static int nowayout = WATCHDOG_NOWAYOUT; |
1da177e4 | 97 | module_param(nowayout, int, 0); |
325ea4d3 AC |
98 | MODULE_PARM_DESC(nowayout, |
99 | "Watchdog cannot be stopped once started (default=" | |
100 | __MODULE_STRING(WATCHDOG_NOWAYOUT) ")"); | |
1da177e4 LT |
101 | |
102 | #define PFX "machzwd" | |
103 | ||
104 | static struct watchdog_info zf_info = { | |
105 | .options = WDIOF_KEEPALIVEPING | WDIOF_MAGICCLOSE, | |
106 | .firmware_version = 1, | |
107 | .identity = "ZF-Logic watchdog", | |
108 | }; | |
109 | ||
110 | ||
111 | /* | |
112 | * action refers to action taken when watchdog resets | |
113 | * 0 = GEN_RESET | |
114 | * 1 = GEN_SMI | |
115 | * 2 = GEN_NMI | |
116 | * 3 = GEN_SCI | |
117 | * defaults to GEN_RESET (0) | |
118 | */ | |
325ea4d3 | 119 | static int action; |
1da177e4 LT |
120 | module_param(action, int, 0); |
121 | MODULE_PARM_DESC(action, "after watchdog resets, generate: 0 = RESET(*) 1 = SMI 2 = NMI 3 = SCI"); | |
122 | ||
82eb7c50 JS |
123 | static void zf_ping(unsigned long data); |
124 | ||
1da177e4 LT |
125 | static int zf_action = GEN_RESET; |
126 | static unsigned long zf_is_open; | |
127 | static char zf_expect_close; | |
c7dfd0cc | 128 | static DEFINE_SPINLOCK(zf_port_lock); |
82eb7c50 | 129 | static DEFINE_TIMER(zf_timer, zf_ping, 0, 0); |
325ea4d3 | 130 | static unsigned long next_heartbeat; |
1da177e4 LT |
131 | |
132 | ||
133 | /* timeout for user land heart beat (10 seconds) */ | |
134 | #define ZF_USER_TIMEO (HZ*10) | |
135 | ||
136 | /* timeout for hardware watchdog (~500ms) */ | |
137 | #define ZF_HW_TIMEO (HZ/2) | |
138 | ||
139 | /* number of ticks on WD#1 (driven by a 32KHz clock, 2s) */ | |
140 | #define ZF_CTIMEOUT 0xffff | |
141 | ||
142 | #ifndef ZF_DEBUG | |
143 | # define dprintk(format, args...) | |
144 | #else | |
fa9363c5 | 145 | # define dprintk(format, args...) printk(KERN_DEBUG PFX ":%s:%d: " format, __func__, __LINE__ , ## args) |
1da177e4 LT |
146 | #endif |
147 | ||
148 | ||
149 | static inline void zf_set_status(unsigned char new) | |
150 | { | |
151 | zf_writeb(STATUS, new); | |
152 | } | |
153 | ||
154 | ||
155 | /* CONTROL register functions */ | |
156 | ||
157 | static inline unsigned short zf_get_control(void) | |
158 | { | |
159 | return zf_readw(CONTROL); | |
160 | } | |
161 | ||
162 | static inline void zf_set_control(unsigned short new) | |
163 | { | |
164 | zf_writew(CONTROL, new); | |
165 | } | |
166 | ||
167 | ||
168 | /* WD#? counter functions */ | |
169 | /* | |
170 | * Just set counter value | |
171 | */ | |
172 | ||
173 | static inline void zf_set_timer(unsigned short new, unsigned char n) | |
174 | { | |
325ea4d3 AC |
175 | switch (n) { |
176 | case WD1: | |
177 | zf_writew(COUNTER_1, new); | |
178 | case WD2: | |
179 | zf_writeb(COUNTER_2, new > 0xff ? 0xff : new); | |
180 | default: | |
181 | return; | |
1da177e4 LT |
182 | } |
183 | } | |
184 | ||
185 | /* | |
186 | * stop hardware timer | |
187 | */ | |
188 | static void zf_timer_off(void) | |
189 | { | |
190 | unsigned int ctrl_reg = 0; | |
191 | unsigned long flags; | |
192 | ||
193 | /* stop internal ping */ | |
194 | del_timer_sync(&zf_timer); | |
195 | ||
196 | spin_lock_irqsave(&zf_port_lock, flags); | |
197 | /* stop watchdog timer */ | |
198 | ctrl_reg = zf_get_control(); | |
199 | ctrl_reg |= (ENABLE_WD1|ENABLE_WD2); /* disable wd1 and wd2 */ | |
200 | ctrl_reg &= ~(ENABLE_WD1|ENABLE_WD2); | |
201 | zf_set_control(ctrl_reg); | |
202 | spin_unlock_irqrestore(&zf_port_lock, flags); | |
203 | ||
204 | printk(KERN_INFO PFX ": Watchdog timer is now disabled\n"); | |
205 | } | |
206 | ||
207 | ||
208 | /* | |
209 | * start hardware timer | |
210 | */ | |
211 | static void zf_timer_on(void) | |
212 | { | |
213 | unsigned int ctrl_reg = 0; | |
214 | unsigned long flags; | |
215 | ||
216 | spin_lock_irqsave(&zf_port_lock, flags); | |
217 | ||
218 | zf_writeb(PULSE_LEN, 0xff); | |
219 | ||
220 | zf_set_timer(ZF_CTIMEOUT, WD1); | |
221 | ||
222 | /* user land ping */ | |
223 | next_heartbeat = jiffies + ZF_USER_TIMEO; | |
224 | ||
225 | /* start the timer for internal ping */ | |
82eb7c50 | 226 | mod_timer(&zf_timer, jiffies + ZF_HW_TIMEO); |
1da177e4 LT |
227 | |
228 | /* start watchdog timer */ | |
229 | ctrl_reg = zf_get_control(); | |
230 | ctrl_reg |= (ENABLE_WD1|zf_action); | |
231 | zf_set_control(ctrl_reg); | |
232 | spin_unlock_irqrestore(&zf_port_lock, flags); | |
233 | ||
234 | printk(KERN_INFO PFX ": Watchdog timer is now enabled\n"); | |
235 | } | |
236 | ||
237 | ||
238 | static void zf_ping(unsigned long data) | |
239 | { | |
240 | unsigned int ctrl_reg = 0; | |
241 | unsigned long flags; | |
242 | ||
243 | zf_writeb(COUNTER_2, 0xff); | |
244 | ||
325ea4d3 | 245 | if (time_before(jiffies, next_heartbeat)) { |
1da177e4 | 246 | dprintk("time_before: %ld\n", next_heartbeat - jiffies); |
1da177e4 LT |
247 | /* |
248 | * reset event is activated by transition from 0 to 1 on | |
249 | * RESET_WD1 bit and we assume that it is already zero... | |
250 | */ | |
251 | ||
252 | spin_lock_irqsave(&zf_port_lock, flags); | |
253 | ctrl_reg = zf_get_control(); | |
254 | ctrl_reg |= RESET_WD1; | |
255 | zf_set_control(ctrl_reg); | |
256 | ||
257 | /* ...and nothing changes until here */ | |
258 | ctrl_reg &= ~(RESET_WD1); | |
259 | zf_set_control(ctrl_reg); | |
260 | spin_unlock_irqrestore(&zf_port_lock, flags); | |
261 | ||
82eb7c50 | 262 | mod_timer(&zf_timer, jiffies + ZF_HW_TIMEO); |
325ea4d3 | 263 | } else |
1da177e4 | 264 | printk(KERN_CRIT PFX ": I will reset your machine\n"); |
1da177e4 LT |
265 | } |
266 | ||
267 | static ssize_t zf_write(struct file *file, const char __user *buf, size_t count, | |
268 | loff_t *ppos) | |
269 | { | |
270 | /* See if we got the magic character */ | |
325ea4d3 | 271 | if (count) { |
1da177e4 LT |
272 | /* |
273 | * no need to check for close confirmation | |
274 | * no way to disable watchdog ;) | |
275 | */ | |
276 | if (!nowayout) { | |
277 | size_t ofs; | |
1da177e4 LT |
278 | /* |
279 | * note: just in case someone wrote the magic character | |
280 | * five months ago... | |
281 | */ | |
282 | zf_expect_close = 0; | |
283 | ||
284 | /* now scan */ | |
325ea4d3 | 285 | for (ofs = 0; ofs != count; ofs++) { |
1da177e4 LT |
286 | char c; |
287 | if (get_user(c, buf + ofs)) | |
288 | return -EFAULT; | |
325ea4d3 | 289 | if (c == 'V') { |
1da177e4 LT |
290 | zf_expect_close = 42; |
291 | dprintk("zf_expect_close = 42\n"); | |
292 | } | |
293 | } | |
294 | } | |
295 | ||
296 | /* | |
297 | * Well, anyhow someone wrote to us, | |
298 | * we should return that favour | |
299 | */ | |
300 | next_heartbeat = jiffies + ZF_USER_TIMEO; | |
301 | dprintk("user ping at %ld\n", jiffies); | |
1da177e4 | 302 | } |
1da177e4 LT |
303 | return count; |
304 | } | |
305 | ||
325ea4d3 | 306 | static long zf_ioctl(struct file *file, unsigned int cmd, unsigned long arg) |
1da177e4 LT |
307 | { |
308 | void __user *argp = (void __user *)arg; | |
309 | int __user *p = argp; | |
bad77057 AM |
310 | switch (cmd) { |
311 | case WDIOC_GETSUPPORT: | |
312 | if (copy_to_user(argp, &zf_info, sizeof(zf_info))) | |
313 | return -EFAULT; | |
314 | break; | |
bad77057 | 315 | case WDIOC_GETSTATUS: |
5c4eb61b | 316 | case WDIOC_GETBOOTSTATUS: |
bad77057 | 317 | return put_user(0, p); |
bad77057 AM |
318 | case WDIOC_KEEPALIVE: |
319 | zf_ping(0); | |
320 | break; | |
bad77057 AM |
321 | default: |
322 | return -ENOTTY; | |
1da177e4 | 323 | } |
1da177e4 LT |
324 | return 0; |
325 | } | |
326 | ||
327 | static int zf_open(struct inode *inode, struct file *file) | |
328 | { | |
325ea4d3 | 329 | if (test_and_set_bit(0, &zf_is_open)) |
1da177e4 | 330 | return -EBUSY; |
1da177e4 LT |
331 | if (nowayout) |
332 | __module_get(THIS_MODULE); | |
1da177e4 | 333 | zf_timer_on(); |
1da177e4 LT |
334 | return nonseekable_open(inode, file); |
335 | } | |
336 | ||
337 | static int zf_close(struct inode *inode, struct file *file) | |
338 | { | |
325ea4d3 | 339 | if (zf_expect_close == 42) |
1da177e4 | 340 | zf_timer_off(); |
325ea4d3 | 341 | else { |
1da177e4 LT |
342 | del_timer(&zf_timer); |
343 | printk(KERN_ERR PFX ": device file closed unexpectedly. Will not stop the WDT!\n"); | |
344 | } | |
1da177e4 | 345 | clear_bit(0, &zf_is_open); |
1da177e4 | 346 | zf_expect_close = 0; |
1da177e4 LT |
347 | return 0; |
348 | } | |
349 | ||
350 | /* | |
351 | * Notifier for system down | |
352 | */ | |
353 | ||
354 | static int zf_notify_sys(struct notifier_block *this, unsigned long code, | |
355 | void *unused) | |
356 | { | |
325ea4d3 | 357 | if (code == SYS_DOWN || code == SYS_HALT) |
1da177e4 | 358 | zf_timer_off(); |
1da177e4 LT |
359 | return NOTIFY_DONE; |
360 | } | |
361 | ||
62322d25 | 362 | static const struct file_operations zf_fops = { |
325ea4d3 AC |
363 | .owner = THIS_MODULE, |
364 | .llseek = no_llseek, | |
365 | .write = zf_write, | |
366 | .unlocked_ioctl = zf_ioctl, | |
367 | .open = zf_open, | |
368 | .release = zf_close, | |
1da177e4 LT |
369 | }; |
370 | ||
371 | static struct miscdevice zf_miscdev = { | |
372 | .minor = WATCHDOG_MINOR, | |
373 | .name = "watchdog", | |
374 | .fops = &zf_fops, | |
375 | }; | |
325ea4d3 | 376 | |
1da177e4 LT |
377 | |
378 | /* | |
379 | * The device needs to learn about soft shutdowns in order to | |
380 | * turn the timebomb registers off. | |
381 | */ | |
382 | static struct notifier_block zf_notifier = { | |
383 | .notifier_call = zf_notify_sys, | |
384 | }; | |
385 | ||
386 | static void __init zf_show_action(int act) | |
387 | { | |
388 | char *str[] = { "RESET", "SMI", "NMI", "SCI" }; | |
389 | ||
390 | printk(KERN_INFO PFX ": Watchdog using action = %s\n", str[act]); | |
391 | } | |
392 | ||
393 | static int __init zf_init(void) | |
394 | { | |
395 | int ret; | |
396 | ||
325ea4d3 AC |
397 | printk(KERN_INFO PFX |
398 | ": MachZ ZF-Logic Watchdog driver initializing.\n"); | |
1da177e4 LT |
399 | |
400 | ret = zf_get_ZFL_version(); | |
325ea4d3 | 401 | if (!ret || ret == 0xffff) { |
1da177e4 LT |
402 | printk(KERN_WARNING PFX ": no ZF-Logic found\n"); |
403 | return -ENODEV; | |
404 | } | |
405 | ||
325ea4d3 AC |
406 | if (action <= 3 && action >= 0) |
407 | zf_action = zf_action >> action; | |
408 | else | |
1da177e4 LT |
409 | action = 0; |
410 | ||
411 | zf_show_action(action); | |
412 | ||
325ea4d3 | 413 | if (!request_region(ZF_IOBASE, 3, "MachZ ZFL WDT")) { |
1da177e4 LT |
414 | printk(KERN_ERR "cannot reserve I/O ports at %d\n", |
415 | ZF_IOBASE); | |
416 | ret = -EBUSY; | |
417 | goto no_region; | |
418 | } | |
419 | ||
420 | ret = register_reboot_notifier(&zf_notifier); | |
325ea4d3 | 421 | if (ret) { |
1da177e4 LT |
422 | printk(KERN_ERR "can't register reboot notifier (err=%d)\n", |
423 | ret); | |
424 | goto no_reboot; | |
425 | } | |
426 | ||
fb8f7ba0 | 427 | ret = misc_register(&zf_miscdev); |
325ea4d3 | 428 | if (ret) { |
fb8f7ba0 AD |
429 | printk(KERN_ERR "can't misc_register on minor=%d\n", |
430 | WATCHDOG_MINOR); | |
431 | goto no_misc; | |
432 | } | |
433 | ||
1da177e4 LT |
434 | zf_set_status(0); |
435 | zf_set_control(0); | |
436 | ||
1da177e4 LT |
437 | return 0; |
438 | ||
fb8f7ba0 AD |
439 | no_misc: |
440 | unregister_reboot_notifier(&zf_notifier); | |
1da177e4 LT |
441 | no_reboot: |
442 | release_region(ZF_IOBASE, 3); | |
443 | no_region: | |
1da177e4 LT |
444 | return ret; |
445 | } | |
446 | ||
447 | ||
448 | static void __exit zf_exit(void) | |
449 | { | |
450 | zf_timer_off(); | |
451 | ||
452 | misc_deregister(&zf_miscdev); | |
453 | unregister_reboot_notifier(&zf_notifier); | |
454 | release_region(ZF_IOBASE, 3); | |
455 | } | |
456 | ||
457 | module_init(zf_init); | |
458 | module_exit(zf_exit); |