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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> | |
d6547378 AC |
33 | #include <linux/uaccess.h> |
34 | #include <linux/io.h> | |
38ff6fd2 JBD |
35 | |
36 | #define NAME "it8712f_wdt" | |
37 | ||
38 | MODULE_AUTHOR("Jorge Boncompte - DTI2 <jorge@dti2.net>"); | |
39 | MODULE_DESCRIPTION("IT8712F Watchdog Driver"); | |
40 | MODULE_LICENSE("GPL"); | |
41 | MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR); | |
42 | ||
5e699608 | 43 | static int max_units = 255; |
38ff6fd2 JBD |
44 | static int margin = 60; /* in seconds */ |
45 | module_param(margin, int, 0); | |
46 | MODULE_PARM_DESC(margin, "Watchdog margin in seconds"); | |
47 | ||
48 | static int nowayout = WATCHDOG_NOWAYOUT; | |
49 | module_param(nowayout, int, 0); | |
50 | MODULE_PARM_DESC(nowayout, "Disable watchdog shutdown on close"); | |
51 | ||
d6547378 | 52 | static unsigned long wdt_open; |
38ff6fd2 JBD |
53 | static unsigned expect_close; |
54 | static spinlock_t io_lock; | |
5e699608 | 55 | static unsigned char revision; |
38ff6fd2 JBD |
56 | |
57 | /* Dog Food address - We use the game port address */ | |
58 | static unsigned short address; | |
59 | ||
60 | #define REG 0x2e /* The register to read/write */ | |
61 | #define VAL 0x2f /* The value to read/write */ | |
62 | ||
63 | #define LDN 0x07 /* Register: Logical device select */ | |
64 | #define DEVID 0x20 /* Register: Device ID */ | |
65 | #define DEVREV 0x22 /* Register: Device Revision */ | |
66 | #define ACT_REG 0x30 /* LDN Register: Activation */ | |
67 | #define BASE_REG 0x60 /* LDN Register: Base address */ | |
68 | ||
69 | #define IT8712F_DEVID 0x8712 | |
70 | ||
71 | #define LDN_GPIO 0x07 /* GPIO and Watch Dog Timer */ | |
72 | #define LDN_GAME 0x09 /* Game Port */ | |
73 | ||
74 | #define WDT_CONTROL 0x71 /* WDT Register: Control */ | |
75 | #define WDT_CONFIG 0x72 /* WDT Register: Configuration */ | |
76 | #define WDT_TIMEOUT 0x73 /* WDT Register: Timeout Value */ | |
77 | ||
78 | #define WDT_RESET_GAME 0x10 | |
79 | #define WDT_RESET_KBD 0x20 | |
80 | #define WDT_RESET_MOUSE 0x40 | |
81 | #define WDT_RESET_CIR 0x80 | |
82 | ||
83 | #define WDT_UNIT_SEC 0x80 /* If 0 in MINUTES */ | |
84 | ||
85 | #define WDT_OUT_PWROK 0x10 | |
86 | #define WDT_OUT_KRST 0x40 | |
87 | ||
d6547378 | 88 | static int superio_inb(int reg) |
38ff6fd2 JBD |
89 | { |
90 | outb(reg, REG); | |
91 | return inb(VAL); | |
92 | } | |
93 | ||
d6547378 | 94 | static void superio_outb(int val, int reg) |
38ff6fd2 JBD |
95 | { |
96 | outb(reg, REG); | |
97 | outb(val, VAL); | |
98 | } | |
99 | ||
d6547378 | 100 | static int superio_inw(int reg) |
38ff6fd2 JBD |
101 | { |
102 | int val; | |
103 | outb(reg++, REG); | |
104 | val = inb(VAL) << 8; | |
105 | outb(reg, REG); | |
106 | val |= inb(VAL); | |
107 | return val; | |
108 | } | |
109 | ||
d6547378 | 110 | static inline void superio_select(int ldn) |
38ff6fd2 JBD |
111 | { |
112 | outb(LDN, REG); | |
113 | outb(ldn, VAL); | |
114 | } | |
115 | ||
d6547378 | 116 | static inline void superio_enter(void) |
38ff6fd2 JBD |
117 | { |
118 | spin_lock(&io_lock); | |
119 | outb(0x87, REG); | |
120 | outb(0x01, REG); | |
121 | outb(0x55, REG); | |
122 | outb(0x55, REG); | |
123 | } | |
124 | ||
d6547378 | 125 | static inline void superio_exit(void) |
38ff6fd2 JBD |
126 | { |
127 | outb(0x02, REG); | |
128 | outb(0x02, VAL); | |
129 | spin_unlock(&io_lock); | |
130 | } | |
131 | ||
d6547378 | 132 | static inline void it8712f_wdt_ping(void) |
38ff6fd2 JBD |
133 | { |
134 | inb(address); | |
135 | } | |
136 | ||
d6547378 | 137 | static void it8712f_wdt_update_margin(void) |
38ff6fd2 JBD |
138 | { |
139 | int config = WDT_OUT_KRST | WDT_OUT_PWROK; | |
5e699608 AP |
140 | int units = margin; |
141 | ||
142 | /* Switch to minutes precision if the configured margin | |
143 | * value does not fit within the register width. | |
144 | */ | |
145 | if (units <= max_units) { | |
146 | config |= WDT_UNIT_SEC; /* else UNIT is MINUTES */ | |
147 | printk(KERN_INFO NAME ": timer margin %d seconds\n", units); | |
148 | } else { | |
149 | units /= 60; | |
150 | printk(KERN_INFO NAME ": timer margin %d minutes\n", units); | |
151 | } | |
38ff6fd2 JBD |
152 | superio_outb(config, WDT_CONFIG); |
153 | ||
5e699608 | 154 | if (revision >= 0x08) |
0e45adb8 OS |
155 | superio_outb(units >> 8, WDT_TIMEOUT + 1); |
156 | superio_outb(units, WDT_TIMEOUT); | |
5e699608 AP |
157 | } |
158 | ||
d6547378 | 159 | static int it8712f_wdt_get_status(void) |
5e699608 AP |
160 | { |
161 | if (superio_inb(WDT_CONTROL) & 0x01) | |
162 | return WDIOF_CARDRESET; | |
163 | else | |
164 | return 0; | |
38ff6fd2 JBD |
165 | } |
166 | ||
d6547378 | 167 | static void it8712f_wdt_enable(void) |
38ff6fd2 JBD |
168 | { |
169 | printk(KERN_DEBUG NAME ": enabling watchdog timer\n"); | |
170 | superio_enter(); | |
171 | superio_select(LDN_GPIO); | |
172 | ||
173 | superio_outb(WDT_RESET_GAME, WDT_CONTROL); | |
174 | ||
175 | it8712f_wdt_update_margin(); | |
176 | ||
177 | superio_exit(); | |
178 | ||
179 | it8712f_wdt_ping(); | |
180 | } | |
181 | ||
d6547378 | 182 | static void it8712f_wdt_disable(void) |
38ff6fd2 JBD |
183 | { |
184 | printk(KERN_DEBUG NAME ": disabling watchdog timer\n"); | |
185 | ||
186 | superio_enter(); | |
187 | superio_select(LDN_GPIO); | |
188 | ||
189 | superio_outb(0, WDT_CONFIG); | |
190 | superio_outb(0, WDT_CONTROL); | |
cc1020f1 AP |
191 | if (revision >= 0x08) |
192 | superio_outb(0, WDT_TIMEOUT + 1); | |
38ff6fd2 JBD |
193 | superio_outb(0, WDT_TIMEOUT); |
194 | ||
195 | superio_exit(); | |
196 | } | |
197 | ||
d6547378 | 198 | static int it8712f_wdt_notify(struct notifier_block *this, |
38ff6fd2 JBD |
199 | unsigned long code, void *unused) |
200 | { | |
201 | if (code == SYS_HALT || code == SYS_POWER_OFF) | |
202 | if (!nowayout) | |
203 | it8712f_wdt_disable(); | |
204 | ||
205 | return NOTIFY_DONE; | |
206 | } | |
207 | ||
208 | static struct notifier_block it8712f_wdt_notifier = { | |
209 | .notifier_call = it8712f_wdt_notify, | |
210 | }; | |
211 | ||
d6547378 AC |
212 | static ssize_t it8712f_wdt_write(struct file *file, const char __user *data, |
213 | size_t len, loff_t *ppos) | |
38ff6fd2 JBD |
214 | { |
215 | /* check for a magic close character */ | |
216 | if (len) { | |
217 | size_t i; | |
218 | ||
219 | it8712f_wdt_ping(); | |
220 | ||
221 | expect_close = 0; | |
222 | for (i = 0; i < len; ++i) { | |
223 | char c; | |
7944d3a5 | 224 | if (get_user(c, data + i)) |
38ff6fd2 JBD |
225 | return -EFAULT; |
226 | if (c == 'V') | |
227 | expect_close = 42; | |
228 | } | |
229 | } | |
230 | ||
231 | return len; | |
232 | } | |
233 | ||
d6547378 AC |
234 | static long it8712f_wdt_ioctl(struct file *file, unsigned int cmd, |
235 | unsigned long arg) | |
38ff6fd2 JBD |
236 | { |
237 | void __user *argp = (void __user *)arg; | |
238 | int __user *p = argp; | |
239 | static struct watchdog_info ident = { | |
240 | .identity = "IT8712F Watchdog", | |
241 | .firmware_version = 1, | |
242 | .options = WDIOF_SETTIMEOUT | WDIOF_KEEPALIVEPING, | |
243 | }; | |
5e699608 | 244 | int value; |
38ff6fd2 JBD |
245 | |
246 | switch (cmd) { | |
38ff6fd2 JBD |
247 | case WDIOC_GETSUPPORT: |
248 | if (copy_to_user(argp, &ident, sizeof(ident))) | |
249 | return -EFAULT; | |
250 | return 0; | |
251 | case WDIOC_GETSTATUS: | |
5e699608 AP |
252 | superio_enter(); |
253 | superio_select(LDN_GPIO); | |
254 | ||
255 | value = it8712f_wdt_get_status(); | |
256 | ||
257 | superio_exit(); | |
258 | ||
259 | return put_user(value, p); | |
38ff6fd2 JBD |
260 | case WDIOC_GETBOOTSTATUS: |
261 | return put_user(0, p); | |
262 | case WDIOC_KEEPALIVE: | |
263 | it8712f_wdt_ping(); | |
264 | return 0; | |
265 | case WDIOC_SETTIMEOUT: | |
5e699608 | 266 | if (get_user(value, p)) |
38ff6fd2 | 267 | return -EFAULT; |
5e699608 AP |
268 | if (value < 1) |
269 | return -EINVAL; | |
270 | if (value > (max_units * 60)) | |
38ff6fd2 | 271 | return -EINVAL; |
5e699608 | 272 | margin = value; |
38ff6fd2 JBD |
273 | superio_enter(); |
274 | superio_select(LDN_GPIO); | |
275 | ||
276 | it8712f_wdt_update_margin(); | |
277 | ||
278 | superio_exit(); | |
279 | it8712f_wdt_ping(); | |
5e699608 | 280 | /* Fall through */ |
38ff6fd2 JBD |
281 | case WDIOC_GETTIMEOUT: |
282 | if (put_user(margin, p)) | |
283 | return -EFAULT; | |
284 | return 0; | |
0c06090c WVS |
285 | default: |
286 | return -ENOTTY; | |
38ff6fd2 JBD |
287 | } |
288 | } | |
289 | ||
d6547378 | 290 | static int it8712f_wdt_open(struct inode *inode, struct file *file) |
38ff6fd2 JBD |
291 | { |
292 | /* only allow one at a time */ | |
d6547378 | 293 | if (test_and_set_bit(0, &wdt_open)) |
38ff6fd2 JBD |
294 | return -EBUSY; |
295 | it8712f_wdt_enable(); | |
38ff6fd2 JBD |
296 | return nonseekable_open(inode, file); |
297 | } | |
298 | ||
d6547378 | 299 | static int it8712f_wdt_release(struct inode *inode, struct file *file) |
38ff6fd2 JBD |
300 | { |
301 | if (expect_close != 42) { | |
302 | printk(KERN_WARNING NAME | |
303 | ": watchdog device closed unexpectedly, will not" | |
304 | " disable the watchdog timer\n"); | |
305 | } else if (!nowayout) { | |
306 | it8712f_wdt_disable(); | |
307 | } | |
308 | expect_close = 0; | |
d6547378 | 309 | clear_bit(0, &wdt_open); |
38ff6fd2 JBD |
310 | |
311 | return 0; | |
312 | } | |
313 | ||
b47a166e | 314 | static const struct file_operations it8712f_wdt_fops = { |
38ff6fd2 JBD |
315 | .owner = THIS_MODULE, |
316 | .llseek = no_llseek, | |
317 | .write = it8712f_wdt_write, | |
d6547378 | 318 | .unlocked_ioctl = it8712f_wdt_ioctl, |
38ff6fd2 JBD |
319 | .open = it8712f_wdt_open, |
320 | .release = it8712f_wdt_release, | |
321 | }; | |
322 | ||
323 | static struct miscdevice it8712f_wdt_miscdev = { | |
324 | .minor = WATCHDOG_MINOR, | |
325 | .name = "watchdog", | |
326 | .fops = &it8712f_wdt_fops, | |
327 | }; | |
328 | ||
d6547378 | 329 | static int __init it8712f_wdt_find(unsigned short *address) |
38ff6fd2 JBD |
330 | { |
331 | int err = -ENODEV; | |
332 | int chip_type; | |
333 | ||
334 | superio_enter(); | |
335 | chip_type = superio_inw(DEVID); | |
336 | if (chip_type != IT8712F_DEVID) | |
337 | goto exit; | |
338 | ||
339 | superio_select(LDN_GAME); | |
340 | superio_outb(1, ACT_REG); | |
341 | if (!(superio_inb(ACT_REG) & 0x01)) { | |
342 | printk(KERN_ERR NAME ": Device not activated, skipping\n"); | |
343 | goto exit; | |
344 | } | |
345 | ||
346 | *address = superio_inw(BASE_REG); | |
347 | if (*address == 0) { | |
348 | printk(KERN_ERR NAME ": Base address not set, skipping\n"); | |
349 | goto exit; | |
350 | } | |
351 | ||
352 | err = 0; | |
5e699608 AP |
353 | revision = superio_inb(DEVREV) & 0x0f; |
354 | ||
355 | /* Later revisions have 16-bit values per datasheet 0.9.1 */ | |
356 | if (revision >= 0x08) | |
357 | max_units = 65535; | |
358 | ||
359 | if (margin > (max_units * 60)) | |
360 | margin = (max_units * 60); | |
361 | ||
362 | printk(KERN_INFO NAME ": Found IT%04xF chip revision %d - " | |
38ff6fd2 | 363 | "using DogFood address 0x%x\n", |
5e699608 | 364 | chip_type, revision, *address); |
38ff6fd2 JBD |
365 | |
366 | exit: | |
367 | superio_exit(); | |
368 | return err; | |
369 | } | |
370 | ||
d6547378 | 371 | static int __init it8712f_wdt_init(void) |
38ff6fd2 JBD |
372 | { |
373 | int err = 0; | |
374 | ||
375 | spin_lock_init(&io_lock); | |
376 | ||
377 | if (it8712f_wdt_find(&address)) | |
378 | return -ENODEV; | |
379 | ||
380 | if (!request_region(address, 1, "IT8712F Watchdog")) { | |
381 | printk(KERN_WARNING NAME ": watchdog I/O region busy\n"); | |
382 | return -EBUSY; | |
383 | } | |
384 | ||
385 | it8712f_wdt_disable(); | |
386 | ||
38ff6fd2 JBD |
387 | err = register_reboot_notifier(&it8712f_wdt_notifier); |
388 | if (err) { | |
389 | printk(KERN_ERR NAME ": unable to register reboot notifier\n"); | |
390 | goto out; | |
391 | } | |
392 | ||
393 | err = misc_register(&it8712f_wdt_miscdev); | |
394 | if (err) { | |
395 | printk(KERN_ERR NAME | |
396 | ": cannot register miscdev on minor=%d (err=%d)\n", | |
397 | WATCHDOG_MINOR, err); | |
398 | goto reboot_out; | |
399 | } | |
400 | ||
401 | return 0; | |
402 | ||
403 | ||
404 | reboot_out: | |
405 | unregister_reboot_notifier(&it8712f_wdt_notifier); | |
406 | out: | |
407 | release_region(address, 1); | |
408 | return err; | |
409 | } | |
410 | ||
d6547378 | 411 | static void __exit it8712f_wdt_exit(void) |
38ff6fd2 JBD |
412 | { |
413 | misc_deregister(&it8712f_wdt_miscdev); | |
414 | unregister_reboot_notifier(&it8712f_wdt_notifier); | |
415 | release_region(address, 1); | |
416 | } | |
417 | ||
418 | module_init(it8712f_wdt_init); | |
419 | module_exit(it8712f_wdt_exit); |