Commit | Line | Data |
---|---|---|
2874c5fd | 1 | // SPDX-License-Identifier: GPL-2.0-or-later |
38ff6fd2 JBD |
2 | /* |
3 | * IT8712F "Smart Guardian" Watchdog support | |
4 | * | |
5 | * Copyright (c) 2006-2007 Jorge Boncompte - DTI2 <jorge@dti2.net> | |
6 | * | |
7 | * Based on info and code taken from: | |
8 | * | |
9 | * drivers/char/watchdog/scx200_wdt.c | |
10 | * drivers/hwmon/it87.c | |
5e699608 AP |
11 | * IT8712F EC-LPC I/O Preliminary Specification 0.8.2 |
12 | * IT8712F EC-LPC I/O Preliminary Specification 0.9.3 | |
38ff6fd2 | 13 | * |
38ff6fd2 JBD |
14 | * The author(s) of this software shall not be held liable for damages |
15 | * of any nature resulting due to the use of this software. This | |
16 | * software is provided AS-IS with no warranties. | |
17 | */ | |
18 | ||
27c766aa JP |
19 | #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt |
20 | ||
38ff6fd2 JBD |
21 | #include <linux/module.h> |
22 | #include <linux/moduleparam.h> | |
23 | #include <linux/init.h> | |
24 | #include <linux/miscdevice.h> | |
25 | #include <linux/watchdog.h> | |
26 | #include <linux/notifier.h> | |
27 | #include <linux/reboot.h> | |
28 | #include <linux/fs.h> | |
38ff6fd2 | 29 | #include <linux/spinlock.h> |
d6547378 AC |
30 | #include <linux/uaccess.h> |
31 | #include <linux/io.h> | |
22602868 | 32 | #include <linux/ioport.h> |
38ff6fd2 | 33 | |
27c766aa | 34 | #define DEBUG |
38ff6fd2 JBD |
35 | #define NAME "it8712f_wdt" |
36 | ||
37 | MODULE_AUTHOR("Jorge Boncompte - DTI2 <jorge@dti2.net>"); | |
38 | MODULE_DESCRIPTION("IT8712F Watchdog Driver"); | |
39 | MODULE_LICENSE("GPL"); | |
38ff6fd2 | 40 | |
5e699608 | 41 | static int max_units = 255; |
38ff6fd2 JBD |
42 | static int margin = 60; /* in seconds */ |
43 | module_param(margin, int, 0); | |
44 | MODULE_PARM_DESC(margin, "Watchdog margin in seconds"); | |
45 | ||
86a1e189 WVS |
46 | static bool nowayout = WATCHDOG_NOWAYOUT; |
47 | module_param(nowayout, bool, 0); | |
38ff6fd2 JBD |
48 | MODULE_PARM_DESC(nowayout, "Disable watchdog shutdown on close"); |
49 | ||
d6547378 | 50 | static unsigned long wdt_open; |
38ff6fd2 | 51 | static unsigned expect_close; |
5e699608 | 52 | static unsigned char revision; |
38ff6fd2 JBD |
53 | |
54 | /* Dog Food address - We use the game port address */ | |
55 | static unsigned short address; | |
56 | ||
57 | #define REG 0x2e /* The register to read/write */ | |
58 | #define VAL 0x2f /* The value to read/write */ | |
59 | ||
60 | #define LDN 0x07 /* Register: Logical device select */ | |
61 | #define DEVID 0x20 /* Register: Device ID */ | |
62 | #define DEVREV 0x22 /* Register: Device Revision */ | |
63 | #define ACT_REG 0x30 /* LDN Register: Activation */ | |
64 | #define BASE_REG 0x60 /* LDN Register: Base address */ | |
65 | ||
66 | #define IT8712F_DEVID 0x8712 | |
67 | ||
68 | #define LDN_GPIO 0x07 /* GPIO and Watch Dog Timer */ | |
5f3b2756 | 69 | #define LDN_GAME 0x09 /* Game Port */ |
38ff6fd2 JBD |
70 | |
71 | #define WDT_CONTROL 0x71 /* WDT Register: Control */ | |
72 | #define WDT_CONFIG 0x72 /* WDT Register: Configuration */ | |
73 | #define WDT_TIMEOUT 0x73 /* WDT Register: Timeout Value */ | |
74 | ||
f0fc1074 TJL |
75 | #define WDT_RESET_GAME 0x10 /* Reset timer on read or write to game port */ |
76 | #define WDT_RESET_KBD 0x20 /* Reset timer on keyboard interrupt */ | |
77 | #define WDT_RESET_MOUSE 0x40 /* Reset timer on mouse interrupt */ | |
78 | #define WDT_RESET_CIR 0x80 /* Reset timer on consumer IR interrupt */ | |
38ff6fd2 JBD |
79 | |
80 | #define WDT_UNIT_SEC 0x80 /* If 0 in MINUTES */ | |
81 | ||
f0fc1074 TJL |
82 | #define WDT_OUT_PWROK 0x10 /* Pulse PWROK on timeout */ |
83 | #define WDT_OUT_KRST 0x40 /* Pulse reset on timeout */ | |
38ff6fd2 | 84 | |
a422088d TJL |
85 | static int wdt_control_reg = WDT_RESET_GAME; |
86 | module_param(wdt_control_reg, int, 0); | |
87 | MODULE_PARM_DESC(wdt_control_reg, "Value to write to watchdog control " | |
88 | "register. The default WDT_RESET_GAME resets the timer on " | |
89 | "game port reads that this driver generates. You can also " | |
90 | "use KBD, MOUSE or CIR if you have some external way to " | |
91 | "generate those interrupts."); | |
92 | ||
d6547378 | 93 | static int superio_inb(int reg) |
38ff6fd2 JBD |
94 | { |
95 | outb(reg, REG); | |
96 | return inb(VAL); | |
97 | } | |
98 | ||
d6547378 | 99 | static void superio_outb(int val, int reg) |
38ff6fd2 JBD |
100 | { |
101 | outb(reg, REG); | |
102 | outb(val, VAL); | |
103 | } | |
104 | ||
d6547378 | 105 | static int superio_inw(int reg) |
38ff6fd2 JBD |
106 | { |
107 | int val; | |
108 | outb(reg++, REG); | |
109 | val = inb(VAL) << 8; | |
110 | outb(reg, REG); | |
111 | val |= inb(VAL); | |
112 | return val; | |
113 | } | |
114 | ||
d6547378 | 115 | static inline void superio_select(int ldn) |
38ff6fd2 JBD |
116 | { |
117 | outb(LDN, REG); | |
118 | outb(ldn, VAL); | |
119 | } | |
120 | ||
a134b825 | 121 | static inline int superio_enter(void) |
38ff6fd2 | 122 | { |
a134b825 NG |
123 | /* |
124 | * Try to reserve REG and REG + 1 for exclusive access. | |
125 | */ | |
126 | if (!request_muxed_region(REG, 2, NAME)) | |
127 | return -EBUSY; | |
128 | ||
38ff6fd2 JBD |
129 | outb(0x87, REG); |
130 | outb(0x01, REG); | |
131 | outb(0x55, REG); | |
132 | outb(0x55, REG); | |
a134b825 | 133 | return 0; |
38ff6fd2 JBD |
134 | } |
135 | ||
d6547378 | 136 | static inline void superio_exit(void) |
38ff6fd2 JBD |
137 | { |
138 | outb(0x02, REG); | |
139 | outb(0x02, VAL); | |
a134b825 | 140 | release_region(REG, 2); |
38ff6fd2 JBD |
141 | } |
142 | ||
d6547378 | 143 | static inline void it8712f_wdt_ping(void) |
38ff6fd2 | 144 | { |
a422088d TJL |
145 | if (wdt_control_reg & WDT_RESET_GAME) |
146 | inb(address); | |
38ff6fd2 JBD |
147 | } |
148 | ||
d6547378 | 149 | static void it8712f_wdt_update_margin(void) |
38ff6fd2 JBD |
150 | { |
151 | int config = WDT_OUT_KRST | WDT_OUT_PWROK; | |
5e699608 AP |
152 | int units = margin; |
153 | ||
154 | /* Switch to minutes precision if the configured margin | |
155 | * value does not fit within the register width. | |
156 | */ | |
157 | if (units <= max_units) { | |
158 | config |= WDT_UNIT_SEC; /* else UNIT is MINUTES */ | |
27c766aa | 159 | pr_info("timer margin %d seconds\n", units); |
5e699608 AP |
160 | } else { |
161 | units /= 60; | |
27c766aa | 162 | pr_info("timer margin %d minutes\n", units); |
5e699608 | 163 | } |
38ff6fd2 JBD |
164 | superio_outb(config, WDT_CONFIG); |
165 | ||
5e699608 | 166 | if (revision >= 0x08) |
0e45adb8 OS |
167 | superio_outb(units >> 8, WDT_TIMEOUT + 1); |
168 | superio_outb(units, WDT_TIMEOUT); | |
5e699608 AP |
169 | } |
170 | ||
d6547378 | 171 | static int it8712f_wdt_get_status(void) |
5e699608 AP |
172 | { |
173 | if (superio_inb(WDT_CONTROL) & 0x01) | |
174 | return WDIOF_CARDRESET; | |
175 | else | |
176 | return 0; | |
38ff6fd2 JBD |
177 | } |
178 | ||
a134b825 | 179 | static int it8712f_wdt_enable(void) |
38ff6fd2 | 180 | { |
a134b825 NG |
181 | int ret = superio_enter(); |
182 | if (ret) | |
183 | return ret; | |
184 | ||
27c766aa | 185 | pr_debug("enabling watchdog timer\n"); |
38ff6fd2 JBD |
186 | superio_select(LDN_GPIO); |
187 | ||
a422088d | 188 | superio_outb(wdt_control_reg, WDT_CONTROL); |
38ff6fd2 JBD |
189 | |
190 | it8712f_wdt_update_margin(); | |
191 | ||
192 | superio_exit(); | |
193 | ||
194 | it8712f_wdt_ping(); | |
a134b825 NG |
195 | |
196 | return 0; | |
38ff6fd2 JBD |
197 | } |
198 | ||
a134b825 | 199 | static int it8712f_wdt_disable(void) |
38ff6fd2 | 200 | { |
a134b825 NG |
201 | int ret = superio_enter(); |
202 | if (ret) | |
203 | return ret; | |
38ff6fd2 | 204 | |
27c766aa | 205 | pr_debug("disabling watchdog timer\n"); |
38ff6fd2 JBD |
206 | superio_select(LDN_GPIO); |
207 | ||
208 | superio_outb(0, WDT_CONFIG); | |
209 | superio_outb(0, WDT_CONTROL); | |
cc1020f1 AP |
210 | if (revision >= 0x08) |
211 | superio_outb(0, WDT_TIMEOUT + 1); | |
38ff6fd2 JBD |
212 | superio_outb(0, WDT_TIMEOUT); |
213 | ||
214 | superio_exit(); | |
a134b825 | 215 | return 0; |
38ff6fd2 JBD |
216 | } |
217 | ||
d6547378 | 218 | static int it8712f_wdt_notify(struct notifier_block *this, |
38ff6fd2 JBD |
219 | unsigned long code, void *unused) |
220 | { | |
221 | if (code == SYS_HALT || code == SYS_POWER_OFF) | |
222 | if (!nowayout) | |
223 | it8712f_wdt_disable(); | |
224 | ||
225 | return NOTIFY_DONE; | |
226 | } | |
227 | ||
228 | static struct notifier_block it8712f_wdt_notifier = { | |
229 | .notifier_call = it8712f_wdt_notify, | |
230 | }; | |
231 | ||
d6547378 AC |
232 | static ssize_t it8712f_wdt_write(struct file *file, const char __user *data, |
233 | size_t len, loff_t *ppos) | |
38ff6fd2 JBD |
234 | { |
235 | /* check for a magic close character */ | |
236 | if (len) { | |
237 | size_t i; | |
238 | ||
239 | it8712f_wdt_ping(); | |
240 | ||
241 | expect_close = 0; | |
242 | for (i = 0; i < len; ++i) { | |
243 | char c; | |
7944d3a5 | 244 | if (get_user(c, data + i)) |
38ff6fd2 JBD |
245 | return -EFAULT; |
246 | if (c == 'V') | |
247 | expect_close = 42; | |
248 | } | |
249 | } | |
250 | ||
251 | return len; | |
252 | } | |
253 | ||
d6547378 AC |
254 | static long it8712f_wdt_ioctl(struct file *file, unsigned int cmd, |
255 | unsigned long arg) | |
38ff6fd2 JBD |
256 | { |
257 | void __user *argp = (void __user *)arg; | |
258 | int __user *p = argp; | |
42747d71 | 259 | static const struct watchdog_info ident = { |
38ff6fd2 JBD |
260 | .identity = "IT8712F Watchdog", |
261 | .firmware_version = 1, | |
e73a7802 WVS |
262 | .options = WDIOF_SETTIMEOUT | WDIOF_KEEPALIVEPING | |
263 | WDIOF_MAGICCLOSE, | |
38ff6fd2 | 264 | }; |
5e699608 | 265 | int value; |
a134b825 | 266 | int ret; |
38ff6fd2 JBD |
267 | |
268 | switch (cmd) { | |
38ff6fd2 JBD |
269 | case WDIOC_GETSUPPORT: |
270 | if (copy_to_user(argp, &ident, sizeof(ident))) | |
271 | return -EFAULT; | |
272 | return 0; | |
273 | case WDIOC_GETSTATUS: | |
a134b825 NG |
274 | ret = superio_enter(); |
275 | if (ret) | |
276 | return ret; | |
5e699608 AP |
277 | superio_select(LDN_GPIO); |
278 | ||
279 | value = it8712f_wdt_get_status(); | |
280 | ||
281 | superio_exit(); | |
282 | ||
283 | return put_user(value, p); | |
38ff6fd2 JBD |
284 | case WDIOC_GETBOOTSTATUS: |
285 | return put_user(0, p); | |
286 | case WDIOC_KEEPALIVE: | |
287 | it8712f_wdt_ping(); | |
288 | return 0; | |
289 | case WDIOC_SETTIMEOUT: | |
5e699608 | 290 | if (get_user(value, p)) |
38ff6fd2 | 291 | return -EFAULT; |
5e699608 AP |
292 | if (value < 1) |
293 | return -EINVAL; | |
294 | if (value > (max_units * 60)) | |
38ff6fd2 | 295 | return -EINVAL; |
5e699608 | 296 | margin = value; |
a134b825 NG |
297 | ret = superio_enter(); |
298 | if (ret) | |
299 | return ret; | |
38ff6fd2 JBD |
300 | superio_select(LDN_GPIO); |
301 | ||
302 | it8712f_wdt_update_margin(); | |
303 | ||
304 | superio_exit(); | |
305 | it8712f_wdt_ping(); | |
5e699608 | 306 | /* Fall through */ |
38ff6fd2 JBD |
307 | case WDIOC_GETTIMEOUT: |
308 | if (put_user(margin, p)) | |
309 | return -EFAULT; | |
310 | return 0; | |
0c06090c WVS |
311 | default: |
312 | return -ENOTTY; | |
38ff6fd2 JBD |
313 | } |
314 | } | |
315 | ||
d6547378 | 316 | static int it8712f_wdt_open(struct inode *inode, struct file *file) |
38ff6fd2 | 317 | { |
a134b825 | 318 | int ret; |
38ff6fd2 | 319 | /* only allow one at a time */ |
d6547378 | 320 | if (test_and_set_bit(0, &wdt_open)) |
38ff6fd2 | 321 | return -EBUSY; |
a134b825 NG |
322 | |
323 | ret = it8712f_wdt_enable(); | |
324 | if (ret) | |
325 | return ret; | |
c5bf68fe | 326 | return stream_open(inode, file); |
38ff6fd2 JBD |
327 | } |
328 | ||
d6547378 | 329 | static int it8712f_wdt_release(struct inode *inode, struct file *file) |
38ff6fd2 JBD |
330 | { |
331 | if (expect_close != 42) { | |
27c766aa | 332 | pr_warn("watchdog device closed unexpectedly, will not disable the watchdog timer\n"); |
38ff6fd2 | 333 | } else if (!nowayout) { |
a134b825 | 334 | if (it8712f_wdt_disable()) |
27c766aa | 335 | pr_warn("Watchdog disable failed\n"); |
38ff6fd2 JBD |
336 | } |
337 | expect_close = 0; | |
d6547378 | 338 | clear_bit(0, &wdt_open); |
38ff6fd2 JBD |
339 | |
340 | return 0; | |
341 | } | |
342 | ||
b47a166e | 343 | static const struct file_operations it8712f_wdt_fops = { |
38ff6fd2 JBD |
344 | .owner = THIS_MODULE, |
345 | .llseek = no_llseek, | |
346 | .write = it8712f_wdt_write, | |
d6547378 | 347 | .unlocked_ioctl = it8712f_wdt_ioctl, |
38ff6fd2 JBD |
348 | .open = it8712f_wdt_open, |
349 | .release = it8712f_wdt_release, | |
350 | }; | |
351 | ||
352 | static struct miscdevice it8712f_wdt_miscdev = { | |
353 | .minor = WATCHDOG_MINOR, | |
354 | .name = "watchdog", | |
355 | .fops = &it8712f_wdt_fops, | |
356 | }; | |
357 | ||
d6547378 | 358 | static int __init it8712f_wdt_find(unsigned short *address) |
38ff6fd2 JBD |
359 | { |
360 | int err = -ENODEV; | |
361 | int chip_type; | |
a134b825 NG |
362 | int ret = superio_enter(); |
363 | if (ret) | |
364 | return ret; | |
38ff6fd2 | 365 | |
38ff6fd2 JBD |
366 | chip_type = superio_inw(DEVID); |
367 | if (chip_type != IT8712F_DEVID) | |
368 | goto exit; | |
369 | ||
370 | superio_select(LDN_GAME); | |
371 | superio_outb(1, ACT_REG); | |
372 | if (!(superio_inb(ACT_REG) & 0x01)) { | |
27c766aa | 373 | pr_err("Device not activated, skipping\n"); |
38ff6fd2 JBD |
374 | goto exit; |
375 | } | |
376 | ||
377 | *address = superio_inw(BASE_REG); | |
378 | if (*address == 0) { | |
27c766aa | 379 | pr_err("Base address not set, skipping\n"); |
38ff6fd2 JBD |
380 | goto exit; |
381 | } | |
382 | ||
383 | err = 0; | |
5e699608 AP |
384 | revision = superio_inb(DEVREV) & 0x0f; |
385 | ||
386 | /* Later revisions have 16-bit values per datasheet 0.9.1 */ | |
387 | if (revision >= 0x08) | |
388 | max_units = 65535; | |
389 | ||
390 | if (margin > (max_units * 60)) | |
391 | margin = (max_units * 60); | |
392 | ||
27c766aa | 393 | pr_info("Found IT%04xF chip revision %d - using DogFood address 0x%x\n", |
5e699608 | 394 | chip_type, revision, *address); |
38ff6fd2 JBD |
395 | |
396 | exit: | |
397 | superio_exit(); | |
398 | return err; | |
399 | } | |
400 | ||
d6547378 | 401 | static int __init it8712f_wdt_init(void) |
38ff6fd2 JBD |
402 | { |
403 | int err = 0; | |
404 | ||
38ff6fd2 JBD |
405 | if (it8712f_wdt_find(&address)) |
406 | return -ENODEV; | |
407 | ||
408 | if (!request_region(address, 1, "IT8712F Watchdog")) { | |
27c766aa | 409 | pr_warn("watchdog I/O region busy\n"); |
38ff6fd2 JBD |
410 | return -EBUSY; |
411 | } | |
412 | ||
a134b825 NG |
413 | err = it8712f_wdt_disable(); |
414 | if (err) { | |
27c766aa | 415 | pr_err("unable to disable watchdog timer\n"); |
a134b825 NG |
416 | goto out; |
417 | } | |
38ff6fd2 | 418 | |
38ff6fd2 JBD |
419 | err = register_reboot_notifier(&it8712f_wdt_notifier); |
420 | if (err) { | |
27c766aa | 421 | pr_err("unable to register reboot notifier\n"); |
38ff6fd2 JBD |
422 | goto out; |
423 | } | |
424 | ||
425 | err = misc_register(&it8712f_wdt_miscdev); | |
426 | if (err) { | |
27c766aa JP |
427 | pr_err("cannot register miscdev on minor=%d (err=%d)\n", |
428 | WATCHDOG_MINOR, err); | |
38ff6fd2 JBD |
429 | goto reboot_out; |
430 | } | |
431 | ||
432 | return 0; | |
433 | ||
434 | ||
435 | reboot_out: | |
436 | unregister_reboot_notifier(&it8712f_wdt_notifier); | |
437 | out: | |
438 | release_region(address, 1); | |
439 | return err; | |
440 | } | |
441 | ||
d6547378 | 442 | static void __exit it8712f_wdt_exit(void) |
38ff6fd2 JBD |
443 | { |
444 | misc_deregister(&it8712f_wdt_miscdev); | |
445 | unregister_reboot_notifier(&it8712f_wdt_notifier); | |
446 | release_region(address, 1); | |
447 | } | |
448 | ||
449 | module_init(it8712f_wdt_init); | |
450 | module_exit(it8712f_wdt_exit); |