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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 |
10 | * IT8712F EC-LPC I/O Preliminary Specification 0.8.2 |
11 | * IT8712F EC-LPC I/O Preliminary Specification 0.9.3 |
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 | #include <linux/uaccess.h> |
34 | #include <linux/io.h> |
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 | |
43 | static int max_units = 255; |
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 | |
52 | static unsigned long wdt_open; |
53 | static unsigned expect_close; |
54 | static spinlock_t io_lock; |
55 | static unsigned char revision; |
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 | |
88 | static int superio_inb(int reg) |
89 | { |
90 | outb(reg, REG); |
91 | return inb(VAL); |
92 | } |
93 | |
94 | static void superio_outb(int val, int reg) |
95 | { |
96 | outb(reg, REG); |
97 | outb(val, VAL); |
98 | } |
99 | |
100 | static int superio_inw(int reg) |
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 | |
110 | static inline void superio_select(int ldn) |
111 | { |
112 | outb(LDN, REG); |
113 | outb(ldn, VAL); |
114 | } |
115 | |
116 | static inline void superio_enter(void) |
117 | { |
118 | spin_lock(&io_lock); |
119 | outb(0x87, REG); |
120 | outb(0x01, REG); |
121 | outb(0x55, REG); |
122 | outb(0x55, REG); |
123 | } |
124 | |
125 | static inline void superio_exit(void) |
126 | { |
127 | outb(0x02, REG); |
128 | outb(0x02, VAL); |
129 | spin_unlock(&io_lock); |
130 | } |
131 | |
132 | static inline void it8712f_wdt_ping(void) |
133 | { |
134 | inb(address); |
135 | } |
136 | |
137 | static void it8712f_wdt_update_margin(void) |
138 | { |
139 | int config = WDT_OUT_KRST | WDT_OUT_PWROK; |
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 | } |
152 | superio_outb(config, WDT_CONFIG); |
153 | |
154 | if (revision >= 0x08) |
155 | superio_outb(units >> 8, WDT_TIMEOUT + 1); |
156 | superio_outb(units, WDT_TIMEOUT); |
157 | } |
158 | |
159 | static int it8712f_wdt_get_status(void) |
160 | { |
161 | if (superio_inb(WDT_CONTROL) & 0x01) |
162 | return WDIOF_CARDRESET; |
163 | else |
164 | return 0; |
165 | } |
166 | |
167 | static void it8712f_wdt_enable(void) |
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 | |
182 | static void it8712f_wdt_disable(void) |
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); |
191 | if (revision >= 0x08) |
192 | superio_outb(0, WDT_TIMEOUT + 1); |
193 | superio_outb(0, WDT_TIMEOUT); |
194 | |
195 | superio_exit(); |
196 | } |
197 | |
198 | static int it8712f_wdt_notify(struct notifier_block *this, |
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 | |
212 | static ssize_t it8712f_wdt_write(struct file *file, const char __user *data, |
213 | size_t len, loff_t *ppos) |
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; |
224 | if (get_user(c, data + i)) |
225 | return -EFAULT; |
226 | if (c == 'V') |
227 | expect_close = 42; |
228 | } |
229 | } |
230 | |
231 | return len; |
232 | } |
233 | |
234 | static long it8712f_wdt_ioctl(struct file *file, unsigned int cmd, |
235 | unsigned long arg) |
236 | { |
237 | void __user *argp = (void __user *)arg; |
238 | int __user *p = argp; |
239 | static const struct watchdog_info ident = { |
240 | .identity = "IT8712F Watchdog", |
241 | .firmware_version = 1, |
242 | .options = WDIOF_SETTIMEOUT | WDIOF_KEEPALIVEPING | |
243 | WDIOF_MAGICCLOSE, |
244 | }; |
245 | int value; |
246 | |
247 | switch (cmd) { |
248 | case WDIOC_GETSUPPORT: |
249 | if (copy_to_user(argp, &ident, sizeof(ident))) |
250 | return -EFAULT; |
251 | return 0; |
252 | case WDIOC_GETSTATUS: |
253 | superio_enter(); |
254 | superio_select(LDN_GPIO); |
255 | |
256 | value = it8712f_wdt_get_status(); |
257 | |
258 | superio_exit(); |
259 | |
260 | return put_user(value, p); |
261 | case WDIOC_GETBOOTSTATUS: |
262 | return put_user(0, p); |
263 | case WDIOC_KEEPALIVE: |
264 | it8712f_wdt_ping(); |
265 | return 0; |
266 | case WDIOC_SETTIMEOUT: |
267 | if (get_user(value, p)) |
268 | return -EFAULT; |
269 | if (value < 1) |
270 | return -EINVAL; |
271 | if (value > (max_units * 60)) |
272 | return -EINVAL; |
273 | margin = value; |
274 | superio_enter(); |
275 | superio_select(LDN_GPIO); |
276 | |
277 | it8712f_wdt_update_margin(); |
278 | |
279 | superio_exit(); |
280 | it8712f_wdt_ping(); |
281 | /* Fall through */ |
282 | case WDIOC_GETTIMEOUT: |
283 | if (put_user(margin, p)) |
284 | return -EFAULT; |
285 | return 0; |
286 | default: |
287 | return -ENOTTY; |
288 | } |
289 | } |
290 | |
291 | static int it8712f_wdt_open(struct inode *inode, struct file *file) |
292 | { |
293 | /* only allow one at a time */ |
294 | if (test_and_set_bit(0, &wdt_open)) |
295 | return -EBUSY; |
296 | it8712f_wdt_enable(); |
297 | return nonseekable_open(inode, file); |
298 | } |
299 | |
300 | static int it8712f_wdt_release(struct inode *inode, struct file *file) |
301 | { |
302 | if (expect_close != 42) { |
303 | printk(KERN_WARNING NAME |
304 | ": watchdog device closed unexpectedly, will not" |
305 | " disable the watchdog timer\n"); |
306 | } else if (!nowayout) { |
307 | it8712f_wdt_disable(); |
308 | } |
309 | expect_close = 0; |
310 | clear_bit(0, &wdt_open); |
311 | |
312 | return 0; |
313 | } |
314 | |
315 | static const struct file_operations it8712f_wdt_fops = { |
316 | .owner = THIS_MODULE, |
317 | .llseek = no_llseek, |
318 | .write = it8712f_wdt_write, |
319 | .unlocked_ioctl = it8712f_wdt_ioctl, |
320 | .open = it8712f_wdt_open, |
321 | .release = it8712f_wdt_release, |
322 | }; |
323 | |
324 | static struct miscdevice it8712f_wdt_miscdev = { |
325 | .minor = WATCHDOG_MINOR, |
326 | .name = "watchdog", |
327 | .fops = &it8712f_wdt_fops, |
328 | }; |
329 | |
330 | static int __init it8712f_wdt_find(unsigned short *address) |
331 | { |
332 | int err = -ENODEV; |
333 | int chip_type; |
334 | |
335 | superio_enter(); |
336 | chip_type = superio_inw(DEVID); |
337 | if (chip_type != IT8712F_DEVID) |
338 | goto exit; |
339 | |
340 | superio_select(LDN_GAME); |
341 | superio_outb(1, ACT_REG); |
342 | if (!(superio_inb(ACT_REG) & 0x01)) { |
343 | printk(KERN_ERR NAME ": Device not activated, skipping\n"); |
344 | goto exit; |
345 | } |
346 | |
347 | *address = superio_inw(BASE_REG); |
348 | if (*address == 0) { |
349 | printk(KERN_ERR NAME ": Base address not set, skipping\n"); |
350 | goto exit; |
351 | } |
352 | |
353 | err = 0; |
354 | revision = superio_inb(DEVREV) & 0x0f; |
355 | |
356 | /* Later revisions have 16-bit values per datasheet 0.9.1 */ |
357 | if (revision >= 0x08) |
358 | max_units = 65535; |
359 | |
360 | if (margin > (max_units * 60)) |
361 | margin = (max_units * 60); |
362 | |
363 | printk(KERN_INFO NAME ": Found IT%04xF chip revision %d - " |
364 | "using DogFood address 0x%x\n", |
365 | chip_type, revision, *address); |
366 | |
367 | exit: |
368 | superio_exit(); |
369 | return err; |
370 | } |
371 | |
372 | static int __init it8712f_wdt_init(void) |
373 | { |
374 | int err = 0; |
375 | |
376 | spin_lock_init(&io_lock); |
377 | |
378 | if (it8712f_wdt_find(&address)) |
379 | return -ENODEV; |
380 | |
381 | if (!request_region(address, 1, "IT8712F Watchdog")) { |
382 | printk(KERN_WARNING NAME ": watchdog I/O region busy\n"); |
383 | return -EBUSY; |
384 | } |
385 | |
386 | it8712f_wdt_disable(); |
387 | |
388 | err = register_reboot_notifier(&it8712f_wdt_notifier); |
389 | if (err) { |
390 | printk(KERN_ERR NAME ": unable to register reboot notifier\n"); |
391 | goto out; |
392 | } |
393 | |
394 | err = misc_register(&it8712f_wdt_miscdev); |
395 | if (err) { |
396 | printk(KERN_ERR NAME |
397 | ": cannot register miscdev on minor=%d (err=%d)\n", |
398 | WATCHDOG_MINOR, err); |
399 | goto reboot_out; |
400 | } |
401 | |
402 | return 0; |
403 | |
404 | |
405 | reboot_out: |
406 | unregister_reboot_notifier(&it8712f_wdt_notifier); |
407 | out: |
408 | release_region(address, 1); |
409 | return err; |
410 | } |
411 | |
412 | static void __exit it8712f_wdt_exit(void) |
413 | { |
414 | misc_deregister(&it8712f_wdt_miscdev); |
415 | unregister_reboot_notifier(&it8712f_wdt_notifier); |
416 | release_region(address, 1); |
417 | } |
418 | |
419 | module_init(it8712f_wdt_init); |
420 | module_exit(it8712f_wdt_exit); |
421 |
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