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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 | |
af901ca1 | 24 | * a system RESET and it starts wd#2 that unconditionally will RESET |
1da177e4 LT |
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 | ||
27c766aa JP |
31 | #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt |
32 | ||
1da177e4 LT |
33 | #include <linux/module.h> |
34 | #include <linux/moduleparam.h> | |
35 | #include <linux/types.h> | |
36 | #include <linux/timer.h> | |
37 | #include <linux/jiffies.h> | |
38 | #include <linux/miscdevice.h> | |
39 | #include <linux/watchdog.h> | |
40 | #include <linux/fs.h> | |
41 | #include <linux/ioport.h> | |
42 | #include <linux/notifier.h> | |
43 | #include <linux/reboot.h> | |
44 | #include <linux/init.h> | |
325ea4d3 AC |
45 | #include <linux/io.h> |
46 | #include <linux/uaccess.h> | |
1da177e4 | 47 | |
1da177e4 LT |
48 | #include <asm/system.h> |
49 | ||
50 | /* ports */ | |
51 | #define ZF_IOBASE 0x218 | |
52 | #define INDEX 0x218 | |
53 | #define DATA_B 0x219 | |
54 | #define DATA_W 0x21A | |
55 | #define DATA_D 0x21A | |
56 | ||
57 | /* indexes */ /* size */ | |
58 | #define ZFL_VERSION 0x02 /* 16 */ | |
5f3b2756 | 59 | #define CONTROL 0x10 /* 16 */ |
1da177e4 LT |
60 | #define STATUS 0x12 /* 8 */ |
61 | #define COUNTER_1 0x0C /* 16 */ | |
62 | #define COUNTER_2 0x0E /* 8 */ | |
63 | #define PULSE_LEN 0x0F /* 8 */ | |
64 | ||
65 | /* controls */ | |
66 | #define ENABLE_WD1 0x0001 | |
67 | #define ENABLE_WD2 0x0002 | |
68 | #define RESET_WD1 0x0010 | |
69 | #define RESET_WD2 0x0020 | |
70 | #define GEN_SCI 0x0100 | |
71 | #define GEN_NMI 0x0200 | |
72 | #define GEN_SMI 0x0400 | |
73 | #define GEN_RESET 0x0800 | |
74 | ||
75 | ||
76 | /* utilities */ | |
77 | ||
78 | #define WD1 0 | |
79 | #define WD2 1 | |
80 | ||
81 | #define zf_writew(port, data) { outb(port, INDEX); outw(data, DATA_W); } | |
82 | #define zf_writeb(port, data) { outb(port, INDEX); outb(data, DATA_B); } | |
83 | #define zf_get_ZFL_version() zf_readw(ZFL_VERSION) | |
84 | ||
85 | ||
86 | static unsigned short zf_readw(unsigned char port) | |
87 | { | |
88 | outb(port, INDEX); | |
89 | return inw(DATA_W); | |
90 | } | |
91 | ||
92 | ||
93 | MODULE_AUTHOR("Fernando Fuganti <fuganti@conectiva.com.br>"); | |
94 | MODULE_DESCRIPTION("MachZ ZF-Logic Watchdog driver"); | |
95 | MODULE_LICENSE("GPL"); | |
96 | MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR); | |
97 | ||
86a1e189 WVS |
98 | static bool nowayout = WATCHDOG_NOWAYOUT; |
99 | module_param(nowayout, bool, 0); | |
325ea4d3 AC |
100 | MODULE_PARM_DESC(nowayout, |
101 | "Watchdog cannot be stopped once started (default=" | |
102 | __MODULE_STRING(WATCHDOG_NOWAYOUT) ")"); | |
1da177e4 LT |
103 | |
104 | #define PFX "machzwd" | |
105 | ||
42747d71 | 106 | static const struct watchdog_info zf_info = { |
1da177e4 LT |
107 | .options = WDIOF_KEEPALIVEPING | WDIOF_MAGICCLOSE, |
108 | .firmware_version = 1, | |
109 | .identity = "ZF-Logic watchdog", | |
110 | }; | |
111 | ||
112 | ||
113 | /* | |
114 | * action refers to action taken when watchdog resets | |
115 | * 0 = GEN_RESET | |
116 | * 1 = GEN_SMI | |
117 | * 2 = GEN_NMI | |
118 | * 3 = GEN_SCI | |
119 | * defaults to GEN_RESET (0) | |
120 | */ | |
325ea4d3 | 121 | static int action; |
1da177e4 | 122 | module_param(action, int, 0); |
a77dba7e WVS |
123 | MODULE_PARM_DESC(action, "after watchdog resets, generate: " |
124 | "0 = RESET(*) 1 = SMI 2 = NMI 3 = SCI"); | |
1da177e4 | 125 | |
82eb7c50 JS |
126 | static void zf_ping(unsigned long data); |
127 | ||
1da177e4 LT |
128 | static int zf_action = GEN_RESET; |
129 | static unsigned long zf_is_open; | |
130 | static char zf_expect_close; | |
c7dfd0cc | 131 | static DEFINE_SPINLOCK(zf_port_lock); |
82eb7c50 | 132 | static DEFINE_TIMER(zf_timer, zf_ping, 0, 0); |
325ea4d3 | 133 | static unsigned long next_heartbeat; |
1da177e4 LT |
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 | |
27c766aa | 146 | #define dprintk(format, args...) |
1da177e4 | 147 | #else |
27c766aa JP |
148 | #define dprintk(format, args...) \ |
149 | pr_debug(":%s:%d: " format, __func__, __LINE__ , ## args) | |
1da177e4 LT |
150 | #endif |
151 | ||
152 | ||
153 | static inline void zf_set_status(unsigned char new) | |
154 | { | |
155 | zf_writeb(STATUS, new); | |
156 | } | |
157 | ||
158 | ||
159 | /* CONTROL register functions */ | |
160 | ||
161 | static inline unsigned short zf_get_control(void) | |
162 | { | |
163 | return zf_readw(CONTROL); | |
164 | } | |
165 | ||
166 | static inline void zf_set_control(unsigned short new) | |
167 | { | |
168 | zf_writew(CONTROL, new); | |
169 | } | |
170 | ||
171 | ||
172 | /* WD#? counter functions */ | |
173 | /* | |
174 | * Just set counter value | |
175 | */ | |
176 | ||
177 | static inline void zf_set_timer(unsigned short new, unsigned char n) | |
178 | { | |
325ea4d3 AC |
179 | switch (n) { |
180 | case WD1: | |
181 | zf_writew(COUNTER_1, new); | |
182 | case WD2: | |
183 | zf_writeb(COUNTER_2, new > 0xff ? 0xff : new); | |
184 | default: | |
185 | return; | |
1da177e4 LT |
186 | } |
187 | } | |
188 | ||
189 | /* | |
190 | * stop hardware timer | |
191 | */ | |
192 | static void zf_timer_off(void) | |
193 | { | |
194 | unsigned int ctrl_reg = 0; | |
195 | unsigned long flags; | |
196 | ||
197 | /* stop internal ping */ | |
198 | del_timer_sync(&zf_timer); | |
199 | ||
200 | spin_lock_irqsave(&zf_port_lock, flags); | |
201 | /* stop watchdog timer */ | |
202 | ctrl_reg = zf_get_control(); | |
203 | ctrl_reg |= (ENABLE_WD1|ENABLE_WD2); /* disable wd1 and wd2 */ | |
204 | ctrl_reg &= ~(ENABLE_WD1|ENABLE_WD2); | |
205 | zf_set_control(ctrl_reg); | |
206 | spin_unlock_irqrestore(&zf_port_lock, flags); | |
207 | ||
27c766aa | 208 | pr_info("Watchdog timer is now disabled\n"); |
1da177e4 LT |
209 | } |
210 | ||
211 | ||
212 | /* | |
213 | * start hardware timer | |
214 | */ | |
215 | static void zf_timer_on(void) | |
216 | { | |
217 | unsigned int ctrl_reg = 0; | |
218 | unsigned long flags; | |
219 | ||
220 | spin_lock_irqsave(&zf_port_lock, flags); | |
221 | ||
222 | zf_writeb(PULSE_LEN, 0xff); | |
223 | ||
224 | zf_set_timer(ZF_CTIMEOUT, WD1); | |
225 | ||
226 | /* user land ping */ | |
227 | next_heartbeat = jiffies + ZF_USER_TIMEO; | |
228 | ||
229 | /* start the timer for internal ping */ | |
82eb7c50 | 230 | mod_timer(&zf_timer, jiffies + ZF_HW_TIMEO); |
1da177e4 LT |
231 | |
232 | /* start watchdog timer */ | |
233 | ctrl_reg = zf_get_control(); | |
234 | ctrl_reg |= (ENABLE_WD1|zf_action); | |
235 | zf_set_control(ctrl_reg); | |
236 | spin_unlock_irqrestore(&zf_port_lock, flags); | |
237 | ||
27c766aa | 238 | pr_info("Watchdog timer is now enabled\n"); |
1da177e4 LT |
239 | } |
240 | ||
241 | ||
242 | static void zf_ping(unsigned long data) | |
243 | { | |
244 | unsigned int ctrl_reg = 0; | |
245 | unsigned long flags; | |
246 | ||
247 | zf_writeb(COUNTER_2, 0xff); | |
248 | ||
325ea4d3 | 249 | if (time_before(jiffies, next_heartbeat)) { |
1da177e4 | 250 | dprintk("time_before: %ld\n", next_heartbeat - jiffies); |
1da177e4 LT |
251 | /* |
252 | * reset event is activated by transition from 0 to 1 on | |
253 | * RESET_WD1 bit and we assume that it is already zero... | |
254 | */ | |
255 | ||
256 | spin_lock_irqsave(&zf_port_lock, flags); | |
257 | ctrl_reg = zf_get_control(); | |
258 | ctrl_reg |= RESET_WD1; | |
259 | zf_set_control(ctrl_reg); | |
260 | ||
261 | /* ...and nothing changes until here */ | |
262 | ctrl_reg &= ~(RESET_WD1); | |
263 | zf_set_control(ctrl_reg); | |
264 | spin_unlock_irqrestore(&zf_port_lock, flags); | |
265 | ||
82eb7c50 | 266 | mod_timer(&zf_timer, jiffies + ZF_HW_TIMEO); |
325ea4d3 | 267 | } else |
27c766aa | 268 | pr_crit("I will reset your machine\n"); |
1da177e4 LT |
269 | } |
270 | ||
271 | static ssize_t zf_write(struct file *file, const char __user *buf, size_t count, | |
272 | loff_t *ppos) | |
273 | { | |
274 | /* See if we got the magic character */ | |
325ea4d3 | 275 | if (count) { |
1da177e4 LT |
276 | /* |
277 | * no need to check for close confirmation | |
278 | * no way to disable watchdog ;) | |
279 | */ | |
280 | if (!nowayout) { | |
281 | size_t ofs; | |
1da177e4 LT |
282 | /* |
283 | * note: just in case someone wrote the magic character | |
284 | * five months ago... | |
285 | */ | |
286 | zf_expect_close = 0; | |
287 | ||
288 | /* now scan */ | |
325ea4d3 | 289 | for (ofs = 0; ofs != count; ofs++) { |
1da177e4 LT |
290 | char c; |
291 | if (get_user(c, buf + ofs)) | |
292 | return -EFAULT; | |
325ea4d3 | 293 | if (c == 'V') { |
1da177e4 LT |
294 | zf_expect_close = 42; |
295 | dprintk("zf_expect_close = 42\n"); | |
296 | } | |
297 | } | |
298 | } | |
299 | ||
300 | /* | |
301 | * Well, anyhow someone wrote to us, | |
302 | * we should return that favour | |
303 | */ | |
304 | next_heartbeat = jiffies + ZF_USER_TIMEO; | |
305 | dprintk("user ping at %ld\n", jiffies); | |
1da177e4 | 306 | } |
1da177e4 LT |
307 | return count; |
308 | } | |
309 | ||
325ea4d3 | 310 | static long zf_ioctl(struct file *file, unsigned int cmd, unsigned long arg) |
1da177e4 LT |
311 | { |
312 | void __user *argp = (void __user *)arg; | |
313 | int __user *p = argp; | |
bad77057 AM |
314 | switch (cmd) { |
315 | case WDIOC_GETSUPPORT: | |
316 | if (copy_to_user(argp, &zf_info, sizeof(zf_info))) | |
317 | return -EFAULT; | |
318 | break; | |
bad77057 | 319 | case WDIOC_GETSTATUS: |
5c4eb61b | 320 | case WDIOC_GETBOOTSTATUS: |
bad77057 | 321 | return put_user(0, p); |
bad77057 AM |
322 | case WDIOC_KEEPALIVE: |
323 | zf_ping(0); | |
324 | break; | |
bad77057 AM |
325 | default: |
326 | return -ENOTTY; | |
1da177e4 | 327 | } |
1da177e4 LT |
328 | return 0; |
329 | } | |
330 | ||
331 | static int zf_open(struct inode *inode, struct file *file) | |
332 | { | |
325ea4d3 | 333 | if (test_and_set_bit(0, &zf_is_open)) |
1da177e4 | 334 | return -EBUSY; |
1da177e4 LT |
335 | if (nowayout) |
336 | __module_get(THIS_MODULE); | |
1da177e4 | 337 | zf_timer_on(); |
1da177e4 LT |
338 | return nonseekable_open(inode, file); |
339 | } | |
340 | ||
341 | static int zf_close(struct inode *inode, struct file *file) | |
342 | { | |
325ea4d3 | 343 | if (zf_expect_close == 42) |
1da177e4 | 344 | zf_timer_off(); |
325ea4d3 | 345 | else { |
1da177e4 | 346 | del_timer(&zf_timer); |
27c766aa | 347 | pr_err("device file closed unexpectedly. Will not stop the WDT!\n"); |
1da177e4 | 348 | } |
1da177e4 | 349 | clear_bit(0, &zf_is_open); |
1da177e4 | 350 | zf_expect_close = 0; |
1da177e4 LT |
351 | return 0; |
352 | } | |
353 | ||
354 | /* | |
355 | * Notifier for system down | |
356 | */ | |
357 | ||
358 | static int zf_notify_sys(struct notifier_block *this, unsigned long code, | |
359 | void *unused) | |
360 | { | |
325ea4d3 | 361 | if (code == SYS_DOWN || code == SYS_HALT) |
1da177e4 | 362 | zf_timer_off(); |
1da177e4 LT |
363 | return NOTIFY_DONE; |
364 | } | |
365 | ||
62322d25 | 366 | static const struct file_operations zf_fops = { |
325ea4d3 AC |
367 | .owner = THIS_MODULE, |
368 | .llseek = no_llseek, | |
369 | .write = zf_write, | |
370 | .unlocked_ioctl = zf_ioctl, | |
371 | .open = zf_open, | |
372 | .release = zf_close, | |
1da177e4 LT |
373 | }; |
374 | ||
375 | static struct miscdevice zf_miscdev = { | |
376 | .minor = WATCHDOG_MINOR, | |
377 | .name = "watchdog", | |
378 | .fops = &zf_fops, | |
379 | }; | |
325ea4d3 | 380 | |
1da177e4 LT |
381 | |
382 | /* | |
383 | * The device needs to learn about soft shutdowns in order to | |
384 | * turn the timebomb registers off. | |
385 | */ | |
386 | static struct notifier_block zf_notifier = { | |
387 | .notifier_call = zf_notify_sys, | |
388 | }; | |
389 | ||
390 | static void __init zf_show_action(int act) | |
391 | { | |
a2b89cd8 | 392 | static const char * const str[] = { "RESET", "SMI", "NMI", "SCI" }; |
1da177e4 | 393 | |
27c766aa | 394 | pr_info("Watchdog using action = %s\n", str[act]); |
1da177e4 LT |
395 | } |
396 | ||
397 | static int __init zf_init(void) | |
398 | { | |
399 | int ret; | |
400 | ||
27c766aa | 401 | pr_info("MachZ ZF-Logic Watchdog driver initializing\n"); |
1da177e4 LT |
402 | |
403 | ret = zf_get_ZFL_version(); | |
325ea4d3 | 404 | if (!ret || ret == 0xffff) { |
27c766aa | 405 | pr_warn("no ZF-Logic found\n"); |
1da177e4 LT |
406 | return -ENODEV; |
407 | } | |
408 | ||
325ea4d3 AC |
409 | if (action <= 3 && action >= 0) |
410 | zf_action = zf_action >> action; | |
411 | else | |
1da177e4 LT |
412 | action = 0; |
413 | ||
414 | zf_show_action(action); | |
415 | ||
325ea4d3 | 416 | if (!request_region(ZF_IOBASE, 3, "MachZ ZFL WDT")) { |
27c766aa | 417 | pr_err("cannot reserve I/O ports at %d\n", ZF_IOBASE); |
1da177e4 LT |
418 | ret = -EBUSY; |
419 | goto no_region; | |
420 | } | |
421 | ||
422 | ret = register_reboot_notifier(&zf_notifier); | |
325ea4d3 | 423 | if (ret) { |
27c766aa | 424 | pr_err("can't register reboot notifier (err=%d)\n", ret); |
1da177e4 LT |
425 | goto no_reboot; |
426 | } | |
427 | ||
fb8f7ba0 | 428 | ret = misc_register(&zf_miscdev); |
325ea4d3 | 429 | if (ret) { |
27c766aa | 430 | pr_err("can't misc_register on minor=%d\n", WATCHDOG_MINOR); |
fb8f7ba0 AD |
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); |