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3809ad38 IM |
1 | /* |
2 | * SBC8360 Watchdog driver | |
3 | * | |
4 | * (c) Copyright 2005 Webcon, Inc. | |
5 | * | |
6 | * Based on ib700wdt.c, which is based on advantechwdt.c which is based | |
7 | * on acquirewdt.c which is based on wdt.c. | |
8 | * | |
9 | * (c) Copyright 2001 Charles Howes <chowes@vsol.net> | |
10 | * | |
11 | * Based on advantechwdt.c which is based on acquirewdt.c which | |
12 | * is based on wdt.c. | |
13 | * | |
14 | * (c) Copyright 2000-2001 Marek Michalkiewicz <marekm@linux.org.pl> | |
15 | * | |
16 | * Based on acquirewdt.c which is based on wdt.c. | |
17 | * Original copyright messages: | |
18 | * | |
19 | * (c) Copyright 1996 Alan Cox <alan@redhat.com>, All Rights Reserved. | |
20 | * http://www.redhat.com | |
21 | * | |
22 | * This program is free software; you can redistribute it and/or | |
23 | * modify it under the terms of the GNU General Public License | |
24 | * as published by the Free Software Foundation; either version | |
25 | * 2 of the License, or (at your option) any later version. | |
26 | * | |
27 | * Neither Alan Cox nor CymruNet Ltd. admit liability nor provide | |
28 | * warranty for any of this software. This material is provided | |
29 | * "AS-IS" and at no charge. | |
30 | * | |
31 | * (c) Copyright 1995 Alan Cox <alan@redhat.com> | |
32 | * | |
33 | * 14-Dec-2001 Matt Domsch <Matt_Domsch@dell.com> | |
34 | * Added nowayout module option to override CONFIG_WATCHDOG_NOWAYOUT | |
35 | * Added timeout module option to override default | |
36 | * | |
37 | */ | |
38 | ||
39 | #include <linux/config.h> | |
40 | #include <linux/module.h> | |
41 | #include <linux/types.h> | |
42 | #include <linux/miscdevice.h> | |
43 | #include <linux/watchdog.h> | |
44 | #include <linux/ioport.h> | |
45 | #include <linux/delay.h> | |
46 | #include <linux/notifier.h> | |
47 | #include <linux/fs.h> | |
48 | #include <linux/reboot.h> | |
49 | #include <linux/init.h> | |
50 | #include <linux/spinlock.h> | |
51 | #include <linux/moduleparam.h> | |
52 | ||
53 | #include <asm/io.h> | |
54 | #include <asm/uaccess.h> | |
55 | #include <asm/system.h> | |
56 | ||
57 | static unsigned long sbc8360_is_open; | |
58 | static spinlock_t sbc8360_lock; | |
59 | static char expect_close; | |
60 | ||
61 | #define PFX "sbc8360: " | |
62 | ||
63 | /* | |
64 | * | |
65 | * Watchdog Timer Configuration | |
66 | * | |
67 | * The function of the watchdog timer is to reset the system automatically | |
68 | * and is defined at I/O port 0120H and 0121H. To enable the watchdog timer | |
69 | * and allow the system to reset, write appropriate values from the table | |
70 | * below to I/O port 0120H and 0121H. To disable the timer, write a zero | |
71 | * value to I/O port 0121H for the system to stop the watchdog function. | |
72 | * | |
73 | * The following describes how the timer should be programmed (according to | |
74 | * the vendor documentation) | |
75 | * | |
76 | * Enabling Watchdog: | |
77 | * MOV AX,000AH (enable, phase I) | |
78 | * MOV DX,0120H | |
79 | * OUT DX,AX | |
80 | * MOV AX,000BH (enable, phase II) | |
81 | * MOV DX,0120H | |
82 | * OUT DX,AX | |
83 | * MOV AX,000nH (set multiplier n, from 1-4) | |
84 | * MOV DX,0120H | |
85 | * OUT DX,AX | |
86 | * MOV AX,000mH (set base timer m, from 0-F) | |
87 | * MOV DX,0121H | |
88 | * OUT DX,AX | |
89 | * | |
90 | * Reset timer: | |
91 | * MOV AX,000mH (same as set base timer, above) | |
92 | * MOV DX,0121H | |
93 | * OUT DX,AX | |
94 | * | |
95 | * Disabling Watchdog: | |
96 | * MOV AX,0000H (a zero value) | |
97 | * MOV DX,0120H | |
98 | * OUT DX,AX | |
99 | * | |
100 | * Watchdog timeout configuration values: | |
101 | * N | |
102 | * M | 1 2 3 4 | |
103 | * --|---------------------------------- | |
104 | * 0 | 0.5s 5s 50s 100s | |
105 | * 1 | 1s 10s 100s 200s | |
106 | * 2 | 1.5s 15s 150s 300s | |
107 | * 3 | 2s 20s 200s 400s | |
108 | * 4 | 2.5s 25s 250s 500s | |
109 | * 5 | 3s 30s 300s 600s | |
110 | * 6 | 3.5s 35s 350s 700s | |
111 | * 7 | 4s 40s 400s 800s | |
112 | * 8 | 4.5s 45s 450s 900s | |
113 | * 9 | 5s 50s 500s 1000s | |
114 | * A | 5.5s 55s 550s 1100s | |
115 | * B | 6s 60s 600s 1200s | |
116 | * C | 6.5s 65s 650s 1300s | |
117 | * D | 7s 70s 700s 1400s | |
118 | * E | 7.5s 75s 750s 1500s | |
119 | * F | 8s 80s 800s 1600s | |
120 | * | |
121 | * Another way to say the same things is: | |
122 | * For N=1, Timeout = (M+1) * 0.5s | |
123 | * For N=2, Timeout = (M+1) * 5s | |
124 | * For N=3, Timeout = (M+1) * 50s | |
125 | * For N=4, Timeout = (M+1) * 100s | |
126 | * | |
127 | */ | |
128 | ||
129 | static int wd_times[64][2] = { | |
130 | {0, 1}, /* 0 = 0.5s */ | |
131 | {1, 1}, /* 1 = 1s */ | |
132 | {2, 1}, /* 2 = 1.5s */ | |
133 | {3, 1}, /* 3 = 2s */ | |
134 | {4, 1}, /* 4 = 2.5s */ | |
135 | {5, 1}, /* 5 = 3s */ | |
136 | {6, 1}, /* 6 = 3.5s */ | |
137 | {7, 1}, /* 7 = 4s */ | |
138 | {8, 1}, /* 8 = 4.5s */ | |
139 | {9, 1}, /* 9 = 5s */ | |
140 | {0xA, 1}, /* 10 = 5.5s */ | |
141 | {0xB, 1}, /* 11 = 6s */ | |
142 | {0xC, 1}, /* 12 = 6.5s */ | |
143 | {0xD, 1}, /* 13 = 7s */ | |
144 | {0xE, 1}, /* 14 = 7.5s */ | |
145 | {0xF, 1}, /* 15 = 8s */ | |
146 | {0, 2}, /* 16 = 5s */ | |
147 | {1, 2}, /* 17 = 10s */ | |
148 | {2, 2}, /* 18 = 15s */ | |
149 | {3, 2}, /* 19 = 20s */ | |
150 | {4, 2}, /* 20 = 25s */ | |
151 | {5, 2}, /* 21 = 30s */ | |
152 | {6, 2}, /* 22 = 35s */ | |
153 | {7, 2}, /* 23 = 40s */ | |
154 | {8, 2}, /* 24 = 45s */ | |
155 | {9, 2}, /* 25 = 50s */ | |
156 | {0xA, 2}, /* 26 = 55s */ | |
157 | {0xB, 2}, /* 27 = 60s */ | |
158 | {0xC, 2}, /* 28 = 65s */ | |
159 | {0xD, 2}, /* 29 = 70s */ | |
160 | {0xE, 2}, /* 30 = 75s */ | |
161 | {0xF, 2}, /* 31 = 80s */ | |
162 | {0, 3}, /* 32 = 50s */ | |
163 | {1, 3}, /* 33 = 100s */ | |
164 | {2, 3}, /* 34 = 150s */ | |
165 | {3, 3}, /* 35 = 200s */ | |
166 | {4, 3}, /* 36 = 250s */ | |
167 | {5, 3}, /* 37 = 300s */ | |
168 | {6, 3}, /* 38 = 350s */ | |
169 | {7, 3}, /* 39 = 400s */ | |
170 | {8, 3}, /* 40 = 450s */ | |
171 | {9, 3}, /* 41 = 500s */ | |
172 | {0xA, 3}, /* 42 = 550s */ | |
173 | {0xB, 3}, /* 43 = 600s */ | |
174 | {0xC, 3}, /* 44 = 650s */ | |
175 | {0xD, 3}, /* 45 = 700s */ | |
176 | {0xE, 3}, /* 46 = 750s */ | |
177 | {0xF, 3}, /* 47 = 800s */ | |
178 | {0, 4}, /* 48 = 100s */ | |
179 | {1, 4}, /* 49 = 200s */ | |
180 | {2, 4}, /* 50 = 300s */ | |
181 | {3, 4}, /* 51 = 400s */ | |
182 | {4, 4}, /* 52 = 500s */ | |
183 | {5, 4}, /* 53 = 600s */ | |
184 | {6, 4}, /* 54 = 700s */ | |
185 | {7, 4}, /* 55 = 800s */ | |
186 | {8, 4}, /* 56 = 900s */ | |
187 | {9, 4}, /* 57 = 1000s */ | |
188 | {0xA, 4}, /* 58 = 1100s */ | |
189 | {0xB, 4}, /* 59 = 1200s */ | |
190 | {0xC, 4}, /* 60 = 1300s */ | |
191 | {0xD, 4}, /* 61 = 1400s */ | |
192 | {0xE, 4}, /* 62 = 1500s */ | |
193 | {0xF, 4} /* 63 = 1600s */ | |
194 | }; | |
195 | ||
196 | #define SBC8360_ENABLE 0x120 | |
197 | #define SBC8360_BASETIME 0x121 | |
198 | ||
199 | static int timeout = 27; | |
200 | static int wd_margin = 0xB; | |
201 | static int wd_multiplier = 2; | |
202 | ||
203 | #ifdef CONFIG_WATCHDOG_NOWAYOUT | |
204 | static int nowayout = 1; | |
205 | #else | |
206 | static int nowayout = 0; | |
207 | #endif | |
208 | ||
209 | module_param(timeout, int, 27); | |
210 | MODULE_PARM_DESC(timeout, "Index into timeout table (0-63) (default=27 (60s))"); | |
211 | module_param(nowayout, int, 0); | |
212 | MODULE_PARM_DESC(nowayout, | |
213 | "Watchdog cannot be stopped once started (default=CONFIG_WATCHDOG_NOWAYOUT)"); | |
214 | ||
215 | /* | |
216 | * Kernel methods. | |
217 | */ | |
218 | ||
219 | /* Activate and pre-configure watchdog */ | |
220 | static void sbc8360_activate(void) | |
221 | { | |
222 | /* Enable the watchdog */ | |
223 | outb(0x0A, SBC8360_ENABLE); | |
224 | msleep_interruptible(100); | |
225 | outb(0x0B, SBC8360_ENABLE); | |
226 | msleep_interruptible(100); | |
227 | /* Set timeout multiplier */ | |
228 | outb(wd_multiplier, SBC8360_ENABLE); | |
229 | msleep_interruptible(100); | |
230 | /* Nothing happens until first sbc8360_ping() */ | |
231 | } | |
232 | ||
233 | /* Kernel pings watchdog */ | |
234 | static void sbc8360_ping(void) | |
235 | { | |
236 | /* Write the base timer register */ | |
237 | outb(wd_margin, SBC8360_BASETIME); | |
238 | } | |
239 | ||
240 | /* Userspace pings kernel driver, or requests clean close */ | |
241 | static ssize_t sbc8360_write(struct file *file, const char __user * buf, | |
242 | size_t count, loff_t * ppos) | |
243 | { | |
244 | if (count) { | |
245 | if (!nowayout) { | |
246 | size_t i; | |
247 | ||
248 | /* In case it was set long ago */ | |
249 | expect_close = 0; | |
250 | ||
251 | for (i = 0; i != count; i++) { | |
252 | char c; | |
253 | if (get_user(c, buf + i)) | |
254 | return -EFAULT; | |
255 | if (c == 'V') | |
256 | expect_close = 42; | |
257 | } | |
258 | } | |
259 | sbc8360_ping(); | |
260 | } | |
261 | return count; | |
262 | } | |
263 | ||
264 | static int sbc8360_open(struct inode *inode, struct file *file) | |
265 | { | |
266 | spin_lock(&sbc8360_lock); | |
267 | if (test_and_set_bit(0, &sbc8360_is_open)) { | |
268 | spin_unlock(&sbc8360_lock); | |
269 | return -EBUSY; | |
270 | } | |
271 | if (nowayout) | |
272 | __module_get(THIS_MODULE); | |
273 | ||
274 | /* Activate and ping once to start the countdown */ | |
275 | spin_unlock(&sbc8360_lock); | |
276 | sbc8360_activate(); | |
277 | sbc8360_ping(); | |
278 | return nonseekable_open(inode, file); | |
279 | } | |
280 | ||
281 | static int sbc8360_close(struct inode *inode, struct file *file) | |
282 | { | |
283 | spin_lock(&sbc8360_lock); | |
284 | if (expect_close == 42) | |
285 | outb(0, SBC8360_ENABLE); | |
286 | else | |
287 | printk(KERN_CRIT PFX | |
288 | "SBC8360 device closed unexpectedly. SBC8360 will not stop!\n"); | |
289 | ||
290 | clear_bit(0, &sbc8360_is_open); | |
291 | expect_close = 0; | |
292 | spin_unlock(&sbc8360_lock); | |
293 | return 0; | |
294 | } | |
295 | ||
296 | /* | |
297 | * Notifier for system down | |
298 | */ | |
299 | ||
300 | static int sbc8360_notify_sys(struct notifier_block *this, unsigned long code, | |
301 | void *unused) | |
302 | { | |
303 | if (code == SYS_DOWN || code == SYS_HALT) { | |
304 | /* Disable the SBC8360 Watchdog */ | |
305 | outb(0, SBC8360_ENABLE); | |
306 | } | |
307 | return NOTIFY_DONE; | |
308 | } | |
309 | ||
310 | /* | |
311 | * Kernel Interfaces | |
312 | */ | |
313 | ||
314 | static struct file_operations sbc8360_fops = { | |
315 | .owner = THIS_MODULE, | |
316 | .llseek = no_llseek, | |
317 | .write = sbc8360_write, | |
318 | .open = sbc8360_open, | |
319 | .release = sbc8360_close, | |
320 | }; | |
321 | ||
322 | static struct miscdevice sbc8360_miscdev = { | |
323 | .minor = WATCHDOG_MINOR, | |
324 | .name = "watchdog", | |
325 | .fops = &sbc8360_fops, | |
326 | }; | |
327 | ||
328 | /* | |
329 | * The SBC8360 needs to learn about soft shutdowns in order to | |
330 | * turn the timebomb registers off. | |
331 | */ | |
332 | ||
333 | static struct notifier_block sbc8360_notifier = { | |
334 | .notifier_call = sbc8360_notify_sys, | |
335 | }; | |
336 | ||
337 | static int __init sbc8360_init(void) | |
338 | { | |
339 | int res; | |
340 | unsigned long int mseconds = 60000; | |
341 | ||
342 | spin_lock_init(&sbc8360_lock); | |
343 | res = misc_register(&sbc8360_miscdev); | |
344 | if (res) { | |
345 | printk(KERN_ERR PFX "failed to register misc device\n"); | |
346 | goto out_nomisc; | |
347 | } | |
348 | ||
349 | if (!request_region(SBC8360_ENABLE, 1, "SBC8360")) { | |
350 | printk(KERN_ERR PFX "ENABLE method I/O %X is not available.\n", | |
351 | SBC8360_ENABLE); | |
352 | res = -EIO; | |
353 | goto out_noenablereg; | |
354 | } | |
355 | if (!request_region(SBC8360_BASETIME, 1, "SBC8360")) { | |
356 | printk(KERN_ERR PFX | |
357 | "BASETIME method I/O %X is not available.\n", | |
358 | SBC8360_BASETIME); | |
359 | res = -EIO; | |
360 | goto out_nobasetimereg; | |
361 | } | |
362 | ||
363 | res = register_reboot_notifier(&sbc8360_notifier); | |
364 | if (res) { | |
365 | printk(KERN_ERR PFX "Failed to register reboot notifier.\n"); | |
366 | goto out_noreboot; | |
367 | } | |
368 | ||
369 | if (timeout < 0 || timeout > 63) { | |
370 | printk(KERN_ERR PFX "Invalid timeout index (must be 0-63).\n"); | |
371 | res = -EINVAL; | |
372 | goto out_noreboot; | |
373 | } | |
374 | ||
375 | wd_margin = wd_times[timeout][0]; | |
376 | wd_multiplier = wd_times[timeout][1]; | |
377 | ||
378 | if (wd_multiplier == 1) | |
379 | mseconds = (wd_margin + 1) * 500; | |
380 | else if (wd_multiplier == 2) | |
381 | mseconds = (wd_margin + 1) * 5000; | |
382 | else if (wd_multiplier == 3) | |
383 | mseconds = (wd_margin + 1) * 50000; | |
384 | else if (wd_multiplier == 4) | |
385 | mseconds = (wd_margin + 1) * 100000; | |
386 | ||
387 | /* My kingdom for the ability to print "0.5 seconds" in the kernel! */ | |
388 | printk(KERN_INFO PFX "Timeout set at %ld ms.\n", mseconds); | |
389 | ||
390 | return 0; | |
391 | ||
392 | out_noreboot: | |
393 | release_region(SBC8360_ENABLE, 1); | |
394 | release_region(SBC8360_BASETIME, 1); | |
395 | out_noenablereg: | |
396 | out_nobasetimereg: | |
397 | misc_deregister(&sbc8360_miscdev); | |
398 | out_nomisc: | |
399 | return res; | |
400 | } | |
401 | ||
402 | static void __exit sbc8360_exit(void) | |
403 | { | |
404 | misc_deregister(&sbc8360_miscdev); | |
405 | unregister_reboot_notifier(&sbc8360_notifier); | |
406 | release_region(SBC8360_ENABLE, 1); | |
407 | release_region(SBC8360_BASETIME, 1); | |
408 | } | |
409 | ||
410 | module_init(sbc8360_init); | |
411 | module_exit(sbc8360_exit); | |
412 | ||
413 | MODULE_AUTHOR("Ian E. Morgan <imorgan@webcon.ca>"); | |
414 | MODULE_DESCRIPTION("SBC8360 watchdog driver"); | |
415 | MODULE_LICENSE("GPL"); | |
416 | MODULE_VERSION("1.0"); | |
417 | MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR); | |
418 | ||
419 | /* end of sbc8360.c */ |