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38ff6fd2 JBD |
1 | /* |
2 | * IT8712F "Smart Guardian" Watchdog support | |
3 | * | |
4 | * Copyright (c) 2006-2007 Jorge Boncompte - DTI2 <jorge@dti2.net> | |
5 | * | |
6 | * Based on info and code taken from: | |
7 | * | |
8 | * drivers/char/watchdog/scx200_wdt.c | |
9 | * drivers/hwmon/it87.c | |
5e699608 AP |
10 | * IT8712F EC-LPC I/O Preliminary Specification 0.8.2 |
11 | * IT8712F EC-LPC I/O Preliminary Specification 0.9.3 | |
38ff6fd2 JBD |
12 | * |
13 | * This program is free software; you can redistribute it and/or | |
14 | * modify it under the terms of the GNU General Public License as | |
15 | * published by the Free Software Foundation; either version 2 of the | |
16 | * License, or (at your option) any later version. | |
17 | * | |
18 | * The author(s) of this software shall not be held liable for damages | |
19 | * of any nature resulting due to the use of this software. This | |
20 | * software is provided AS-IS with no warranties. | |
21 | */ | |
22 | ||
23 | #include <linux/module.h> | |
24 | #include <linux/moduleparam.h> | |
25 | #include <linux/init.h> | |
26 | #include <linux/miscdevice.h> | |
27 | #include <linux/watchdog.h> | |
28 | #include <linux/notifier.h> | |
29 | #include <linux/reboot.h> | |
30 | #include <linux/fs.h> | |
31 | #include <linux/pci.h> | |
32 | #include <linux/spinlock.h> | |
33 | ||
34 | #include <asm/uaccess.h> | |
35 | #include <asm/io.h> | |
36 | ||
37 | #define NAME "it8712f_wdt" | |
38 | ||
39 | MODULE_AUTHOR("Jorge Boncompte - DTI2 <jorge@dti2.net>"); | |
40 | MODULE_DESCRIPTION("IT8712F Watchdog Driver"); | |
41 | MODULE_LICENSE("GPL"); | |
42 | MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR); | |
43 | ||
5e699608 | 44 | static int max_units = 255; |
38ff6fd2 JBD |
45 | static int margin = 60; /* in seconds */ |
46 | module_param(margin, int, 0); | |
47 | MODULE_PARM_DESC(margin, "Watchdog margin in seconds"); | |
48 | ||
49 | static int nowayout = WATCHDOG_NOWAYOUT; | |
50 | module_param(nowayout, int, 0); | |
51 | MODULE_PARM_DESC(nowayout, "Disable watchdog shutdown on close"); | |
52 | ||
53 | static struct semaphore it8712f_wdt_sem; | |
54 | static unsigned expect_close; | |
55 | static spinlock_t io_lock; | |
5e699608 | 56 | static unsigned char revision; |
38ff6fd2 JBD |
57 | |
58 | /* Dog Food address - We use the game port address */ | |
59 | static unsigned short address; | |
60 | ||
61 | #define REG 0x2e /* The register to read/write */ | |
62 | #define VAL 0x2f /* The value to read/write */ | |
63 | ||
64 | #define LDN 0x07 /* Register: Logical device select */ | |
65 | #define DEVID 0x20 /* Register: Device ID */ | |
66 | #define DEVREV 0x22 /* Register: Device Revision */ | |
67 | #define ACT_REG 0x30 /* LDN Register: Activation */ | |
68 | #define BASE_REG 0x60 /* LDN Register: Base address */ | |
69 | ||
70 | #define IT8712F_DEVID 0x8712 | |
71 | ||
72 | #define LDN_GPIO 0x07 /* GPIO and Watch Dog Timer */ | |
73 | #define LDN_GAME 0x09 /* Game Port */ | |
74 | ||
75 | #define WDT_CONTROL 0x71 /* WDT Register: Control */ | |
76 | #define WDT_CONFIG 0x72 /* WDT Register: Configuration */ | |
77 | #define WDT_TIMEOUT 0x73 /* WDT Register: Timeout Value */ | |
78 | ||
79 | #define WDT_RESET_GAME 0x10 | |
80 | #define WDT_RESET_KBD 0x20 | |
81 | #define WDT_RESET_MOUSE 0x40 | |
82 | #define WDT_RESET_CIR 0x80 | |
83 | ||
84 | #define WDT_UNIT_SEC 0x80 /* If 0 in MINUTES */ | |
85 | ||
86 | #define WDT_OUT_PWROK 0x10 | |
87 | #define WDT_OUT_KRST 0x40 | |
88 | ||
89 | static int | |
90 | superio_inb(int reg) | |
91 | { | |
92 | outb(reg, REG); | |
93 | return inb(VAL); | |
94 | } | |
95 | ||
96 | static void | |
97 | superio_outb(int val, int reg) | |
98 | { | |
99 | outb(reg, REG); | |
100 | outb(val, VAL); | |
101 | } | |
102 | ||
103 | static int | |
104 | superio_inw(int reg) | |
105 | { | |
106 | int val; | |
107 | outb(reg++, REG); | |
108 | val = inb(VAL) << 8; | |
109 | outb(reg, REG); | |
110 | val |= inb(VAL); | |
111 | return val; | |
112 | } | |
113 | ||
114 | static inline void | |
115 | superio_select(int ldn) | |
116 | { | |
117 | outb(LDN, REG); | |
118 | outb(ldn, VAL); | |
119 | } | |
120 | ||
121 | static inline void | |
122 | superio_enter(void) | |
123 | { | |
124 | spin_lock(&io_lock); | |
125 | outb(0x87, REG); | |
126 | outb(0x01, REG); | |
127 | outb(0x55, REG); | |
128 | outb(0x55, REG); | |
129 | } | |
130 | ||
131 | static inline void | |
132 | superio_exit(void) | |
133 | { | |
134 | outb(0x02, REG); | |
135 | outb(0x02, VAL); | |
136 | spin_unlock(&io_lock); | |
137 | } | |
138 | ||
139 | static inline void | |
140 | it8712f_wdt_ping(void) | |
141 | { | |
142 | inb(address); | |
143 | } | |
144 | ||
145 | static void | |
146 | it8712f_wdt_update_margin(void) | |
147 | { | |
148 | int config = WDT_OUT_KRST | WDT_OUT_PWROK; | |
5e699608 AP |
149 | int units = margin; |
150 | ||
151 | /* Switch to minutes precision if the configured margin | |
152 | * value does not fit within the register width. | |
153 | */ | |
154 | if (units <= max_units) { | |
155 | config |= WDT_UNIT_SEC; /* else UNIT is MINUTES */ | |
156 | printk(KERN_INFO NAME ": timer margin %d seconds\n", units); | |
157 | } else { | |
158 | units /= 60; | |
159 | printk(KERN_INFO NAME ": timer margin %d minutes\n", units); | |
160 | } | |
38ff6fd2 JBD |
161 | superio_outb(config, WDT_CONFIG); |
162 | ||
5e699608 | 163 | if (revision >= 0x08) |
0e45adb8 OS |
164 | superio_outb(units >> 8, WDT_TIMEOUT + 1); |
165 | superio_outb(units, WDT_TIMEOUT); | |
5e699608 AP |
166 | } |
167 | ||
168 | static int | |
169 | it8712f_wdt_get_status(void) | |
170 | { | |
171 | if (superio_inb(WDT_CONTROL) & 0x01) | |
172 | return WDIOF_CARDRESET; | |
173 | else | |
174 | return 0; | |
38ff6fd2 JBD |
175 | } |
176 | ||
177 | static void | |
178 | it8712f_wdt_enable(void) | |
179 | { | |
180 | printk(KERN_DEBUG NAME ": enabling watchdog timer\n"); | |
181 | superio_enter(); | |
182 | superio_select(LDN_GPIO); | |
183 | ||
184 | superio_outb(WDT_RESET_GAME, WDT_CONTROL); | |
185 | ||
186 | it8712f_wdt_update_margin(); | |
187 | ||
188 | superio_exit(); | |
189 | ||
190 | it8712f_wdt_ping(); | |
191 | } | |
192 | ||
193 | static void | |
194 | it8712f_wdt_disable(void) | |
195 | { | |
196 | printk(KERN_DEBUG NAME ": disabling watchdog timer\n"); | |
197 | ||
198 | superio_enter(); | |
199 | superio_select(LDN_GPIO); | |
200 | ||
201 | superio_outb(0, WDT_CONFIG); | |
202 | superio_outb(0, WDT_CONTROL); | |
cc1020f1 AP |
203 | if (revision >= 0x08) |
204 | superio_outb(0, WDT_TIMEOUT + 1); | |
38ff6fd2 JBD |
205 | superio_outb(0, WDT_TIMEOUT); |
206 | ||
207 | superio_exit(); | |
208 | } | |
209 | ||
210 | static int | |
211 | it8712f_wdt_notify(struct notifier_block *this, | |
212 | unsigned long code, void *unused) | |
213 | { | |
214 | if (code == SYS_HALT || code == SYS_POWER_OFF) | |
215 | if (!nowayout) | |
216 | it8712f_wdt_disable(); | |
217 | ||
218 | return NOTIFY_DONE; | |
219 | } | |
220 | ||
221 | static struct notifier_block it8712f_wdt_notifier = { | |
222 | .notifier_call = it8712f_wdt_notify, | |
223 | }; | |
224 | ||
225 | static ssize_t | |
226 | it8712f_wdt_write(struct file *file, const char __user *data, | |
227 | size_t len, loff_t *ppos) | |
228 | { | |
229 | /* check for a magic close character */ | |
230 | if (len) { | |
231 | size_t i; | |
232 | ||
233 | it8712f_wdt_ping(); | |
234 | ||
235 | expect_close = 0; | |
236 | for (i = 0; i < len; ++i) { | |
237 | char c; | |
238 | if (get_user(c, data+i)) | |
239 | return -EFAULT; | |
240 | if (c == 'V') | |
241 | expect_close = 42; | |
242 | } | |
243 | } | |
244 | ||
245 | return len; | |
246 | } | |
247 | ||
248 | static int | |
249 | it8712f_wdt_ioctl(struct inode *inode, struct file *file, | |
250 | unsigned int cmd, unsigned long arg) | |
251 | { | |
252 | void __user *argp = (void __user *)arg; | |
253 | int __user *p = argp; | |
254 | static struct watchdog_info ident = { | |
255 | .identity = "IT8712F Watchdog", | |
256 | .firmware_version = 1, | |
257 | .options = WDIOF_SETTIMEOUT | WDIOF_KEEPALIVEPING, | |
258 | }; | |
5e699608 | 259 | int value; |
38ff6fd2 JBD |
260 | |
261 | switch (cmd) { | |
262 | default: | |
263 | return -ENOTTY; | |
264 | case WDIOC_GETSUPPORT: | |
265 | if (copy_to_user(argp, &ident, sizeof(ident))) | |
266 | return -EFAULT; | |
267 | return 0; | |
268 | case WDIOC_GETSTATUS: | |
5e699608 AP |
269 | superio_enter(); |
270 | superio_select(LDN_GPIO); | |
271 | ||
272 | value = it8712f_wdt_get_status(); | |
273 | ||
274 | superio_exit(); | |
275 | ||
276 | return put_user(value, p); | |
38ff6fd2 JBD |
277 | case WDIOC_GETBOOTSTATUS: |
278 | return put_user(0, p); | |
279 | case WDIOC_KEEPALIVE: | |
280 | it8712f_wdt_ping(); | |
281 | return 0; | |
282 | case WDIOC_SETTIMEOUT: | |
5e699608 | 283 | if (get_user(value, p)) |
38ff6fd2 | 284 | return -EFAULT; |
5e699608 AP |
285 | if (value < 1) |
286 | return -EINVAL; | |
287 | if (value > (max_units * 60)) | |
38ff6fd2 | 288 | return -EINVAL; |
5e699608 | 289 | margin = value; |
38ff6fd2 JBD |
290 | superio_enter(); |
291 | superio_select(LDN_GPIO); | |
292 | ||
293 | it8712f_wdt_update_margin(); | |
294 | ||
295 | superio_exit(); | |
296 | it8712f_wdt_ping(); | |
5e699608 | 297 | /* Fall through */ |
38ff6fd2 JBD |
298 | case WDIOC_GETTIMEOUT: |
299 | if (put_user(margin, p)) | |
300 | return -EFAULT; | |
301 | return 0; | |
302 | } | |
303 | } | |
304 | ||
305 | static int | |
306 | it8712f_wdt_open(struct inode *inode, struct file *file) | |
307 | { | |
308 | /* only allow one at a time */ | |
309 | if (down_trylock(&it8712f_wdt_sem)) | |
310 | return -EBUSY; | |
311 | it8712f_wdt_enable(); | |
312 | ||
313 | return nonseekable_open(inode, file); | |
314 | } | |
315 | ||
316 | static int | |
317 | it8712f_wdt_release(struct inode *inode, struct file *file) | |
318 | { | |
319 | if (expect_close != 42) { | |
320 | printk(KERN_WARNING NAME | |
321 | ": watchdog device closed unexpectedly, will not" | |
322 | " disable the watchdog timer\n"); | |
323 | } else if (!nowayout) { | |
324 | it8712f_wdt_disable(); | |
325 | } | |
326 | expect_close = 0; | |
327 | up(&it8712f_wdt_sem); | |
328 | ||
329 | return 0; | |
330 | } | |
331 | ||
b47a166e | 332 | static const struct file_operations it8712f_wdt_fops = { |
38ff6fd2 JBD |
333 | .owner = THIS_MODULE, |
334 | .llseek = no_llseek, | |
335 | .write = it8712f_wdt_write, | |
336 | .ioctl = it8712f_wdt_ioctl, | |
337 | .open = it8712f_wdt_open, | |
338 | .release = it8712f_wdt_release, | |
339 | }; | |
340 | ||
341 | static struct miscdevice it8712f_wdt_miscdev = { | |
342 | .minor = WATCHDOG_MINOR, | |
343 | .name = "watchdog", | |
344 | .fops = &it8712f_wdt_fops, | |
345 | }; | |
346 | ||
347 | static int __init | |
348 | it8712f_wdt_find(unsigned short *address) | |
349 | { | |
350 | int err = -ENODEV; | |
351 | int chip_type; | |
352 | ||
353 | superio_enter(); | |
354 | chip_type = superio_inw(DEVID); | |
355 | if (chip_type != IT8712F_DEVID) | |
356 | goto exit; | |
357 | ||
358 | superio_select(LDN_GAME); | |
359 | superio_outb(1, ACT_REG); | |
360 | if (!(superio_inb(ACT_REG) & 0x01)) { | |
361 | printk(KERN_ERR NAME ": Device not activated, skipping\n"); | |
362 | goto exit; | |
363 | } | |
364 | ||
365 | *address = superio_inw(BASE_REG); | |
366 | if (*address == 0) { | |
367 | printk(KERN_ERR NAME ": Base address not set, skipping\n"); | |
368 | goto exit; | |
369 | } | |
370 | ||
371 | err = 0; | |
5e699608 AP |
372 | revision = superio_inb(DEVREV) & 0x0f; |
373 | ||
374 | /* Later revisions have 16-bit values per datasheet 0.9.1 */ | |
375 | if (revision >= 0x08) | |
376 | max_units = 65535; | |
377 | ||
378 | if (margin > (max_units * 60)) | |
379 | margin = (max_units * 60); | |
380 | ||
381 | printk(KERN_INFO NAME ": Found IT%04xF chip revision %d - " | |
38ff6fd2 | 382 | "using DogFood address 0x%x\n", |
5e699608 | 383 | chip_type, revision, *address); |
38ff6fd2 JBD |
384 | |
385 | exit: | |
386 | superio_exit(); | |
387 | return err; | |
388 | } | |
389 | ||
390 | static int __init | |
391 | it8712f_wdt_init(void) | |
392 | { | |
393 | int err = 0; | |
394 | ||
395 | spin_lock_init(&io_lock); | |
396 | ||
397 | if (it8712f_wdt_find(&address)) | |
398 | return -ENODEV; | |
399 | ||
400 | if (!request_region(address, 1, "IT8712F Watchdog")) { | |
401 | printk(KERN_WARNING NAME ": watchdog I/O region busy\n"); | |
402 | return -EBUSY; | |
403 | } | |
404 | ||
405 | it8712f_wdt_disable(); | |
406 | ||
407 | sema_init(&it8712f_wdt_sem, 1); | |
408 | ||
409 | err = register_reboot_notifier(&it8712f_wdt_notifier); | |
410 | if (err) { | |
411 | printk(KERN_ERR NAME ": unable to register reboot notifier\n"); | |
412 | goto out; | |
413 | } | |
414 | ||
415 | err = misc_register(&it8712f_wdt_miscdev); | |
416 | if (err) { | |
417 | printk(KERN_ERR NAME | |
418 | ": cannot register miscdev on minor=%d (err=%d)\n", | |
419 | WATCHDOG_MINOR, err); | |
420 | goto reboot_out; | |
421 | } | |
422 | ||
423 | return 0; | |
424 | ||
425 | ||
426 | reboot_out: | |
427 | unregister_reboot_notifier(&it8712f_wdt_notifier); | |
428 | out: | |
429 | release_region(address, 1); | |
430 | return err; | |
431 | } | |
432 | ||
433 | static void __exit | |
434 | it8712f_wdt_exit(void) | |
435 | { | |
436 | misc_deregister(&it8712f_wdt_miscdev); | |
437 | unregister_reboot_notifier(&it8712f_wdt_notifier); | |
438 | release_region(address, 1); | |
439 | } | |
440 | ||
441 | module_init(it8712f_wdt_init); | |
442 | module_exit(it8712f_wdt_exit); |