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7d8b0906 FF |
1 | /* |
2 | * w83697ug/uf WDT driver | |
3 | * | |
4 | * (c) Copyright 2008 Flemming Fransen <ff@nrvissing.net> | |
5 | * reused original code to supoprt w83697ug/uf. | |
6 | * | |
7 | * Based on w83627hf_wdt.c which is based on advantechwdt.c | |
8 | * which is based on wdt.c. | |
9 | * Original copyright messages: | |
10 | * | |
11 | * (c) Copyright 2007 Vlad Drukker <vlad@storewiz.com> | |
12 | * added support for W83627THF. | |
13 | * | |
14 | * (c) Copyright 2003 Pádraig Brady <P@draigBrady.com> | |
15 | * | |
16 | * (c) Copyright 2000-2001 Marek Michalkiewicz <marekm@linux.org.pl> | |
17 | * | |
18 | * (c) Copyright 1996 Alan Cox <alan@redhat.com>, All Rights Reserved. | |
19 | * http://www.redhat.com | |
20 | * | |
21 | * This program is free software; you can redistribute it and/or | |
22 | * modify it under the terms of the GNU General Public License | |
23 | * as published by the Free Software Foundation; either version | |
24 | * 2 of the License, or (at your option) any later version. | |
25 | * | |
26 | * Neither Alan Cox nor CymruNet Ltd. admit liability nor provide | |
27 | * warranty for any of this software. This material is provided | |
28 | * "AS-IS" and at no charge. | |
29 | * | |
30 | * (c) Copyright 1995 Alan Cox <alan@redhat.com> | |
31 | */ | |
32 | ||
33 | #include <linux/module.h> | |
34 | #include <linux/moduleparam.h> | |
35 | #include <linux/types.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> | |
43 | #include <linux/spinlock.h> | |
44 | #include <linux/io.h> | |
45 | #include <linux/uaccess.h> | |
46 | ||
47 | #include <asm/system.h> | |
48 | ||
49 | #define WATCHDOG_NAME "w83697ug/uf WDT" | |
50 | #define PFX WATCHDOG_NAME ": " | |
51 | #define WATCHDOG_TIMEOUT 60 /* 60 sec default timeout */ | |
52 | ||
53 | static unsigned long wdt_is_open; | |
54 | static char expect_close; | |
55 | static DEFINE_SPINLOCK(io_lock); | |
56 | ||
57 | static int wdt_io = 0x2e; | |
58 | module_param(wdt_io, int, 0); | |
59 | MODULE_PARM_DESC(wdt_io, "w83697ug/uf WDT io port (default 0x2e)"); | |
60 | ||
61 | static int timeout = WATCHDOG_TIMEOUT; /* in seconds */ | |
62 | module_param(timeout, int, 0); | |
63 | MODULE_PARM_DESC(timeout, | |
64 | "Watchdog timeout in seconds. 1<= timeout <=255 (default=" | |
65 | __MODULE_STRING(WATCHDOG_TIMEOUT) ")"); | |
66 | ||
67 | static int nowayout = WATCHDOG_NOWAYOUT; | |
68 | module_param(nowayout, int, 0); | |
69 | MODULE_PARM_DESC(nowayout, | |
70 | "Watchdog cannot be stopped once started (default=" | |
71 | __MODULE_STRING(WATCHDOG_NOWAYOUT) ")"); | |
72 | ||
73 | /* | |
74 | * Kernel methods. | |
75 | */ | |
76 | ||
77 | #define WDT_EFER (wdt_io+0) /* Extended Function Enable Registers */ | |
78 | #define WDT_EFIR (wdt_io+0) /* Extended Function Index Register | |
79 | (same as EFER) */ | |
80 | #define WDT_EFDR (WDT_EFIR+1) /* Extended Function Data Register */ | |
81 | ||
82 | static void w83697ug_select_wd_register(void) | |
83 | { | |
84 | unsigned char c; | |
85 | unsigned char version; | |
86 | ||
87 | outb_p(0x87, WDT_EFER); /* Enter extended function mode */ | |
88 | outb_p(0x87, WDT_EFER); /* Again according to manual */ | |
89 | ||
90 | outb(0x20, WDT_EFER); /* check chip version */ | |
91 | version = inb(WDT_EFDR); | |
92 | ||
93 | if (version == 0x68) { /* W83697UG */ | |
94 | printk(KERN_INFO PFX "Watchdog chip version 0x%02x = " | |
95 | "W83697UG/UF found at 0x%04x\n", version, wdt_io); | |
96 | ||
97 | outb_p(0x2b, WDT_EFER); | |
98 | c = inb_p(WDT_EFDR); /* select WDT0 */ | |
99 | c &= ~0x04; | |
100 | outb_p(0x2b, WDT_EFER); | |
101 | outb_p(c, WDT_EFDR); /* set pin118 to WDT0 */ | |
102 | ||
103 | } else { | |
104 | printk(KERN_ERR PFX "No W83697UG/UF could be found\n"); | |
7dc9b48f | 105 | return; |
7d8b0906 FF |
106 | } |
107 | ||
108 | outb_p(0x07, WDT_EFER); /* point to logical device number reg */ | |
109 | outb_p(0x08, WDT_EFDR); /* select logical device 8 (GPIO2) */ | |
110 | outb_p(0x30, WDT_EFER); /* select CR30 */ | |
111 | c = inb_p(WDT_EFDR); | |
112 | outb_p(c || 0x01, WDT_EFDR); /* set bit 0 to activate GPIO2 */ | |
113 | } | |
114 | ||
115 | static void w83697ug_unselect_wd_register(void) | |
116 | { | |
117 | outb_p(0xAA, WDT_EFER); /* Leave extended function mode */ | |
118 | } | |
119 | ||
120 | static void w83697ug_init(void) | |
121 | { | |
122 | unsigned char t; | |
123 | ||
124 | w83697ug_select_wd_register(); | |
125 | ||
126 | outb_p(0xF6, WDT_EFER); /* Select CRF6 */ | |
127 | t = inb_p(WDT_EFDR); /* read CRF6 */ | |
128 | if (t != 0) { | |
129 | printk(KERN_INFO PFX "Watchdog already running." | |
130 | " Resetting timeout to %d sec\n", timeout); | |
131 | outb_p(timeout, WDT_EFDR); /* Write back to CRF6 */ | |
132 | } | |
133 | outb_p(0xF5, WDT_EFER); /* Select CRF5 */ | |
134 | t = inb_p(WDT_EFDR); /* read CRF5 */ | |
135 | t &= ~0x0C; /* set second mode & | |
136 | disable keyboard turning off watchdog */ | |
137 | outb_p(t, WDT_EFDR); /* Write back to CRF5 */ | |
138 | ||
139 | w83697ug_unselect_wd_register(); | |
140 | } | |
141 | ||
142 | static void wdt_ctrl(int timeout) | |
143 | { | |
144 | spin_lock(&io_lock); | |
145 | ||
146 | w83697ug_select_wd_register(); | |
147 | ||
148 | outb_p(0xF4, WDT_EFER); /* Select CRF4 */ | |
149 | outb_p(timeout, WDT_EFDR); /* Write Timeout counter to CRF4 */ | |
150 | ||
151 | w83697ug_unselect_wd_register(); | |
152 | ||
153 | spin_unlock(&io_lock); | |
154 | } | |
155 | ||
156 | static int wdt_ping(void) | |
157 | { | |
158 | wdt_ctrl(timeout); | |
159 | return 0; | |
160 | } | |
161 | ||
162 | static int wdt_disable(void) | |
163 | { | |
164 | wdt_ctrl(0); | |
165 | return 0; | |
166 | } | |
167 | ||
168 | static int wdt_set_heartbeat(int t) | |
169 | { | |
170 | if (t < 1 || t > 255) | |
171 | return -EINVAL; | |
172 | ||
173 | timeout = t; | |
174 | return 0; | |
175 | } | |
176 | ||
177 | static ssize_t wdt_write(struct file *file, const char __user *buf, | |
178 | size_t count, loff_t *ppos) | |
179 | { | |
180 | if (count) { | |
181 | if (!nowayout) { | |
182 | size_t i; | |
183 | ||
184 | expect_close = 0; | |
185 | ||
186 | for (i = 0; i != count; i++) { | |
187 | char c; | |
188 | if (get_user(c, buf + i)) | |
189 | return -EFAULT; | |
190 | if (c == 'V') | |
191 | expect_close = 42; | |
192 | } | |
193 | } | |
194 | wdt_ping(); | |
195 | } | |
196 | return count; | |
197 | } | |
198 | ||
199 | static long wdt_ioctl(struct file *file, unsigned int cmd, unsigned long arg) | |
200 | { | |
201 | void __user *argp = (void __user *)arg; | |
202 | int __user *p = argp; | |
203 | int new_timeout; | |
204 | static const struct watchdog_info ident = { | |
205 | .options = WDIOF_KEEPALIVEPING | | |
206 | WDIOF_SETTIMEOUT | | |
207 | WDIOF_MAGICCLOSE, | |
208 | .firmware_version = 1, | |
209 | .identity = "W83697UG WDT", | |
210 | }; | |
211 | ||
212 | switch (cmd) { | |
213 | case WDIOC_GETSUPPORT: | |
214 | if (copy_to_user(argp, &ident, sizeof(ident))) | |
215 | return -EFAULT; | |
216 | break; | |
217 | ||
218 | case WDIOC_GETSTATUS: | |
219 | case WDIOC_GETBOOTSTATUS: | |
220 | return put_user(0, p); | |
221 | ||
222 | case WDIOC_SETOPTIONS: | |
223 | { | |
224 | int options, retval = -EINVAL; | |
225 | ||
226 | if (get_user(options, p)) | |
227 | return -EFAULT; | |
228 | ||
229 | if (options & WDIOS_DISABLECARD) { | |
230 | wdt_disable(); | |
231 | retval = 0; | |
232 | } | |
233 | ||
234 | if (options & WDIOS_ENABLECARD) { | |
235 | wdt_ping(); | |
236 | retval = 0; | |
237 | } | |
238 | ||
239 | return retval; | |
240 | } | |
241 | ||
242 | case WDIOC_KEEPALIVE: | |
243 | wdt_ping(); | |
244 | break; | |
245 | ||
246 | case WDIOC_SETTIMEOUT: | |
247 | if (get_user(new_timeout, p)) | |
248 | return -EFAULT; | |
249 | if (wdt_set_heartbeat(new_timeout)) | |
250 | return -EINVAL; | |
251 | wdt_ping(); | |
252 | /* Fall */ | |
253 | ||
254 | case WDIOC_GETTIMEOUT: | |
255 | return put_user(timeout, p); | |
256 | ||
257 | default: | |
258 | return -ENOTTY; | |
259 | } | |
260 | return 0; | |
261 | } | |
262 | ||
263 | static int wdt_open(struct inode *inode, struct file *file) | |
264 | { | |
265 | if (test_and_set_bit(0, &wdt_is_open)) | |
266 | return -EBUSY; | |
267 | /* | |
268 | * Activate | |
269 | */ | |
270 | ||
271 | wdt_ping(); | |
272 | return nonseekable_open(inode, file); | |
273 | } | |
274 | ||
275 | static int wdt_close(struct inode *inode, struct file *file) | |
276 | { | |
277 | if (expect_close == 42) | |
278 | wdt_disable(); | |
279 | else { | |
280 | printk(KERN_CRIT PFX | |
281 | "Unexpected close, not stopping watchdog!\n"); | |
282 | wdt_ping(); | |
283 | } | |
284 | expect_close = 0; | |
285 | clear_bit(0, &wdt_is_open); | |
286 | return 0; | |
287 | } | |
288 | ||
289 | /* | |
290 | * Notifier for system down | |
291 | */ | |
292 | ||
293 | static int wdt_notify_sys(struct notifier_block *this, unsigned long code, | |
294 | void *unused) | |
295 | { | |
296 | if (code == SYS_DOWN || code == SYS_HALT) | |
297 | wdt_disable(); /* Turn the WDT off */ | |
298 | ||
299 | return NOTIFY_DONE; | |
300 | } | |
301 | ||
302 | /* | |
303 | * Kernel Interfaces | |
304 | */ | |
305 | ||
306 | static const struct file_operations wdt_fops = { | |
307 | .owner = THIS_MODULE, | |
308 | .llseek = no_llseek, | |
309 | .write = wdt_write, | |
310 | .unlocked_ioctl = wdt_ioctl, | |
311 | .open = wdt_open, | |
312 | .release = wdt_close, | |
313 | }; | |
314 | ||
315 | static struct miscdevice wdt_miscdev = { | |
316 | .minor = WATCHDOG_MINOR, | |
317 | .name = "watchdog", | |
318 | .fops = &wdt_fops, | |
319 | }; | |
320 | ||
321 | /* | |
322 | * The WDT needs to learn about soft shutdowns in order to | |
323 | * turn the timebomb registers off. | |
324 | */ | |
325 | ||
326 | static struct notifier_block wdt_notifier = { | |
327 | .notifier_call = wdt_notify_sys, | |
328 | }; | |
329 | ||
330 | static int __init wdt_init(void) | |
331 | { | |
332 | int ret; | |
333 | ||
334 | printk(KERN_INFO "WDT driver for the Winbond(TM) W83697UG/UF Super I/O chip initialising.\n"); | |
335 | ||
336 | if (wdt_set_heartbeat(timeout)) { | |
337 | wdt_set_heartbeat(WATCHDOG_TIMEOUT); | |
338 | printk(KERN_INFO PFX | |
339 | "timeout value must be 1<=timeout<=255, using %d\n", | |
340 | WATCHDOG_TIMEOUT); | |
341 | } | |
342 | ||
343 | if (!request_region(wdt_io, 1, WATCHDOG_NAME)) { | |
344 | printk(KERN_ERR PFX "I/O address 0x%04x already in use\n", | |
345 | wdt_io); | |
346 | ret = -EIO; | |
347 | goto out; | |
348 | } | |
349 | ||
350 | w83697ug_init(); | |
351 | ||
352 | ret = register_reboot_notifier(&wdt_notifier); | |
353 | if (ret != 0) { | |
354 | printk(KERN_ERR PFX | |
355 | "cannot register reboot notifier (err=%d)\n", ret); | |
356 | goto unreg_regions; | |
357 | } | |
358 | ||
359 | ret = misc_register(&wdt_miscdev); | |
360 | if (ret != 0) { | |
361 | printk(KERN_ERR PFX | |
362 | "cannot register miscdev on minor=%d (err=%d)\n", | |
363 | WATCHDOG_MINOR, ret); | |
364 | goto unreg_reboot; | |
365 | } | |
366 | ||
367 | printk(KERN_INFO PFX "initialized. timeout=%d sec (nowayout=%d)\n", | |
368 | timeout, nowayout); | |
369 | ||
370 | out: | |
371 | return ret; | |
372 | unreg_reboot: | |
373 | unregister_reboot_notifier(&wdt_notifier); | |
374 | unreg_regions: | |
375 | release_region(wdt_io, 1); | |
376 | goto out; | |
377 | } | |
378 | ||
379 | static void __exit wdt_exit(void) | |
380 | { | |
381 | misc_deregister(&wdt_miscdev); | |
382 | unregister_reboot_notifier(&wdt_notifier); | |
383 | release_region(wdt_io, 1); | |
384 | } | |
385 | ||
386 | module_init(wdt_init); | |
387 | module_exit(wdt_exit); | |
388 | ||
389 | MODULE_LICENSE("GPL"); | |
390 | MODULE_AUTHOR("Flemming Frandsen <ff@nrvissing.net>"); | |
391 | MODULE_DESCRIPTION("w83697ug/uf WDT driver"); | |
392 | MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR); |