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Jorge Boncompte [DTI2]38ff6fd2007-11-19 15:09:21 +01001/*
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
Andrew Paprocki5e699602008-02-10 22:11:15 -050010 * IT8712F EC-LPC I/O Preliminary Specification 0.8.2
11 * IT8712F EC-LPC I/O Preliminary Specification 0.9.3
Jorge Boncompte [DTI2]38ff6fd2007-11-19 15:09:21 +010012 *
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>
Alan Coxd6547372008-08-04 17:54:01 +010033#include <linux/uaccess.h>
34#include <linux/io.h>
Jorge Boncompte [DTI2]38ff6fd2007-11-19 15:09:21 +010035
36#define NAME "it8712f_wdt"
37
38MODULE_AUTHOR("Jorge Boncompte - DTI2 <jorge@dti2.net>");
39MODULE_DESCRIPTION("IT8712F Watchdog Driver");
40MODULE_LICENSE("GPL");
41MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR);
42
Andrew Paprocki5e699602008-02-10 22:11:15 -050043static int max_units = 255;
Jorge Boncompte [DTI2]38ff6fd2007-11-19 15:09:21 +010044static int margin = 60; /* in seconds */
45module_param(margin, int, 0);
46MODULE_PARM_DESC(margin, "Watchdog margin in seconds");
47
48static int nowayout = WATCHDOG_NOWAYOUT;
49module_param(nowayout, int, 0);
50MODULE_PARM_DESC(nowayout, "Disable watchdog shutdown on close");
51
Alan Coxd6547372008-08-04 17:54:01 +010052static unsigned long wdt_open;
Jorge Boncompte [DTI2]38ff6fd2007-11-19 15:09:21 +010053static unsigned expect_close;
54static spinlock_t io_lock;
Andrew Paprocki5e699602008-02-10 22:11:15 -050055static unsigned char revision;
Jorge Boncompte [DTI2]38ff6fd2007-11-19 15:09:21 +010056
57/* Dog Food address - We use the game port address */
58static 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 */
Wim Van Sebroeck5f3b2752011-02-23 20:04:38 +000072#define LDN_GAME 0x09 /* Game Port */
Jorge Boncompte [DTI2]38ff6fd2007-11-19 15:09:21 +010073
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
Timo Juhani Lindforsf0fc1072010-09-30 17:08:03 +030078#define WDT_RESET_GAME 0x10 /* Reset timer on read or write to game port */
79#define WDT_RESET_KBD 0x20 /* Reset timer on keyboard interrupt */
80#define WDT_RESET_MOUSE 0x40 /* Reset timer on mouse interrupt */
81#define WDT_RESET_CIR 0x80 /* Reset timer on consumer IR interrupt */
Jorge Boncompte [DTI2]38ff6fd2007-11-19 15:09:21 +010082
83#define WDT_UNIT_SEC 0x80 /* If 0 in MINUTES */
84
Timo Juhani Lindforsf0fc1072010-09-30 17:08:03 +030085#define WDT_OUT_PWROK 0x10 /* Pulse PWROK on timeout */
86#define WDT_OUT_KRST 0x40 /* Pulse reset on timeout */
Jorge Boncompte [DTI2]38ff6fd2007-11-19 15:09:21 +010087
Timo Juhani Lindforsa4220882010-09-30 17:08:04 +030088static int wdt_control_reg = WDT_RESET_GAME;
89module_param(wdt_control_reg, int, 0);
90MODULE_PARM_DESC(wdt_control_reg, "Value to write to watchdog control "
91 "register. The default WDT_RESET_GAME resets the timer on "
92 "game port reads that this driver generates. You can also "
93 "use KBD, MOUSE or CIR if you have some external way to "
94 "generate those interrupts.");
95
Alan Coxd6547372008-08-04 17:54:01 +010096static int superio_inb(int reg)
Jorge Boncompte [DTI2]38ff6fd2007-11-19 15:09:21 +010097{
98 outb(reg, REG);
99 return inb(VAL);
100}
101
Alan Coxd6547372008-08-04 17:54:01 +0100102static void superio_outb(int val, int reg)
Jorge Boncompte [DTI2]38ff6fd2007-11-19 15:09:21 +0100103{
104 outb(reg, REG);
105 outb(val, VAL);
106}
107
Alan Coxd6547372008-08-04 17:54:01 +0100108static int superio_inw(int reg)
Jorge Boncompte [DTI2]38ff6fd2007-11-19 15:09:21 +0100109{
110 int val;
111 outb(reg++, REG);
112 val = inb(VAL) << 8;
113 outb(reg, REG);
114 val |= inb(VAL);
115 return val;
116}
117
Alan Coxd6547372008-08-04 17:54:01 +0100118static inline void superio_select(int ldn)
Jorge Boncompte [DTI2]38ff6fd2007-11-19 15:09:21 +0100119{
120 outb(LDN, REG);
121 outb(ldn, VAL);
122}
123
Alan Coxd6547372008-08-04 17:54:01 +0100124static inline void superio_enter(void)
Jorge Boncompte [DTI2]38ff6fd2007-11-19 15:09:21 +0100125{
126 spin_lock(&io_lock);
127 outb(0x87, REG);
128 outb(0x01, REG);
129 outb(0x55, REG);
130 outb(0x55, REG);
131}
132
Alan Coxd6547372008-08-04 17:54:01 +0100133static inline void superio_exit(void)
Jorge Boncompte [DTI2]38ff6fd2007-11-19 15:09:21 +0100134{
135 outb(0x02, REG);
136 outb(0x02, VAL);
137 spin_unlock(&io_lock);
138}
139
Alan Coxd6547372008-08-04 17:54:01 +0100140static inline void it8712f_wdt_ping(void)
Jorge Boncompte [DTI2]38ff6fd2007-11-19 15:09:21 +0100141{
Timo Juhani Lindforsa4220882010-09-30 17:08:04 +0300142 if (wdt_control_reg & WDT_RESET_GAME)
143 inb(address);
Jorge Boncompte [DTI2]38ff6fd2007-11-19 15:09:21 +0100144}
145
Alan Coxd6547372008-08-04 17:54:01 +0100146static void it8712f_wdt_update_margin(void)
Jorge Boncompte [DTI2]38ff6fd2007-11-19 15:09:21 +0100147{
148 int config = WDT_OUT_KRST | WDT_OUT_PWROK;
Andrew Paprocki5e699602008-02-10 22:11:15 -0500149 int units = margin;
Jorge Boncompte [DTI2]38ff6fd2007-11-19 15:09:21 +0100150
Andrew Paprocki5e699602008-02-10 22:11:15 -0500151 /* 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 }
Jorge Boncompte [DTI2]38ff6fd2007-11-19 15:09:21 +0100161 superio_outb(config, WDT_CONFIG);
162
Andrew Paprocki5e699602008-02-10 22:11:15 -0500163 if (revision >= 0x08)
Oliver Schuster0e45adb2008-04-01 17:06:21 +0200164 superio_outb(units >> 8, WDT_TIMEOUT + 1);
165 superio_outb(units, WDT_TIMEOUT);
Andrew Paprocki5e699602008-02-10 22:11:15 -0500166}
167
Alan Coxd6547372008-08-04 17:54:01 +0100168static int it8712f_wdt_get_status(void)
Andrew Paprocki5e699602008-02-10 22:11:15 -0500169{
170 if (superio_inb(WDT_CONTROL) & 0x01)
171 return WDIOF_CARDRESET;
172 else
173 return 0;
Jorge Boncompte [DTI2]38ff6fd2007-11-19 15:09:21 +0100174}
175
Alan Coxd6547372008-08-04 17:54:01 +0100176static void it8712f_wdt_enable(void)
Jorge Boncompte [DTI2]38ff6fd2007-11-19 15:09:21 +0100177{
178 printk(KERN_DEBUG NAME ": enabling watchdog timer\n");
179 superio_enter();
180 superio_select(LDN_GPIO);
181
Timo Juhani Lindforsa4220882010-09-30 17:08:04 +0300182 superio_outb(wdt_control_reg, WDT_CONTROL);
Jorge Boncompte [DTI2]38ff6fd2007-11-19 15:09:21 +0100183
184 it8712f_wdt_update_margin();
185
186 superio_exit();
187
188 it8712f_wdt_ping();
189}
190
Alan Coxd6547372008-08-04 17:54:01 +0100191static void it8712f_wdt_disable(void)
Jorge Boncompte [DTI2]38ff6fd2007-11-19 15:09:21 +0100192{
193 printk(KERN_DEBUG NAME ": disabling watchdog timer\n");
194
195 superio_enter();
196 superio_select(LDN_GPIO);
197
198 superio_outb(0, WDT_CONFIG);
199 superio_outb(0, WDT_CONTROL);
Andrew Paprockicc1020f2008-04-02 02:43:19 -0400200 if (revision >= 0x08)
201 superio_outb(0, WDT_TIMEOUT + 1);
Jorge Boncompte [DTI2]38ff6fd2007-11-19 15:09:21 +0100202 superio_outb(0, WDT_TIMEOUT);
203
204 superio_exit();
205}
206
Alan Coxd6547372008-08-04 17:54:01 +0100207static int it8712f_wdt_notify(struct notifier_block *this,
Jorge Boncompte [DTI2]38ff6fd2007-11-19 15:09:21 +0100208 unsigned long code, void *unused)
209{
210 if (code == SYS_HALT || code == SYS_POWER_OFF)
211 if (!nowayout)
212 it8712f_wdt_disable();
213
214 return NOTIFY_DONE;
215}
216
217static struct notifier_block it8712f_wdt_notifier = {
218 .notifier_call = it8712f_wdt_notify,
219};
220
Alan Coxd6547372008-08-04 17:54:01 +0100221static ssize_t it8712f_wdt_write(struct file *file, const char __user *data,
222 size_t len, loff_t *ppos)
Jorge Boncompte [DTI2]38ff6fd2007-11-19 15:09:21 +0100223{
224 /* check for a magic close character */
225 if (len) {
226 size_t i;
227
228 it8712f_wdt_ping();
229
230 expect_close = 0;
231 for (i = 0; i < len; ++i) {
232 char c;
Wim Van Sebroeck7944d3a2008-08-06 20:19:41 +0000233 if (get_user(c, data + i))
Jorge Boncompte [DTI2]38ff6fd2007-11-19 15:09:21 +0100234 return -EFAULT;
235 if (c == 'V')
236 expect_close = 42;
237 }
238 }
239
240 return len;
241}
242
Alan Coxd6547372008-08-04 17:54:01 +0100243static long it8712f_wdt_ioctl(struct file *file, unsigned int cmd,
244 unsigned long arg)
Jorge Boncompte [DTI2]38ff6fd2007-11-19 15:09:21 +0100245{
246 void __user *argp = (void __user *)arg;
247 int __user *p = argp;
Wim Van Sebroeck42747d72009-12-26 18:55:22 +0000248 static const struct watchdog_info ident = {
Jorge Boncompte [DTI2]38ff6fd2007-11-19 15:09:21 +0100249 .identity = "IT8712F Watchdog",
250 .firmware_version = 1,
Wim Van Sebroecke73a7802009-05-11 18:33:00 +0000251 .options = WDIOF_SETTIMEOUT | WDIOF_KEEPALIVEPING |
252 WDIOF_MAGICCLOSE,
Jorge Boncompte [DTI2]38ff6fd2007-11-19 15:09:21 +0100253 };
Andrew Paprocki5e699602008-02-10 22:11:15 -0500254 int value;
Jorge Boncompte [DTI2]38ff6fd2007-11-19 15:09:21 +0100255
256 switch (cmd) {
Jorge Boncompte [DTI2]38ff6fd2007-11-19 15:09:21 +0100257 case WDIOC_GETSUPPORT:
258 if (copy_to_user(argp, &ident, sizeof(ident)))
259 return -EFAULT;
260 return 0;
261 case WDIOC_GETSTATUS:
Andrew Paprocki5e699602008-02-10 22:11:15 -0500262 superio_enter();
263 superio_select(LDN_GPIO);
264
265 value = it8712f_wdt_get_status();
266
267 superio_exit();
268
269 return put_user(value, p);
Jorge Boncompte [DTI2]38ff6fd2007-11-19 15:09:21 +0100270 case WDIOC_GETBOOTSTATUS:
271 return put_user(0, p);
272 case WDIOC_KEEPALIVE:
273 it8712f_wdt_ping();
274 return 0;
275 case WDIOC_SETTIMEOUT:
Andrew Paprocki5e699602008-02-10 22:11:15 -0500276 if (get_user(value, p))
Jorge Boncompte [DTI2]38ff6fd2007-11-19 15:09:21 +0100277 return -EFAULT;
Andrew Paprocki5e699602008-02-10 22:11:15 -0500278 if (value < 1)
Jorge Boncompte [DTI2]38ff6fd2007-11-19 15:09:21 +0100279 return -EINVAL;
Andrew Paprocki5e699602008-02-10 22:11:15 -0500280 if (value > (max_units * 60))
281 return -EINVAL;
282 margin = value;
Jorge Boncompte [DTI2]38ff6fd2007-11-19 15:09:21 +0100283 superio_enter();
284 superio_select(LDN_GPIO);
285
286 it8712f_wdt_update_margin();
287
288 superio_exit();
289 it8712f_wdt_ping();
Andrew Paprocki5e699602008-02-10 22:11:15 -0500290 /* Fall through */
Jorge Boncompte [DTI2]38ff6fd2007-11-19 15:09:21 +0100291 case WDIOC_GETTIMEOUT:
292 if (put_user(margin, p))
293 return -EFAULT;
294 return 0;
Wim Van Sebroeck0c060902008-07-18 11:41:17 +0000295 default:
296 return -ENOTTY;
Jorge Boncompte [DTI2]38ff6fd2007-11-19 15:09:21 +0100297 }
298}
299
Alan Coxd6547372008-08-04 17:54:01 +0100300static int it8712f_wdt_open(struct inode *inode, struct file *file)
Jorge Boncompte [DTI2]38ff6fd2007-11-19 15:09:21 +0100301{
302 /* only allow one at a time */
Alan Coxd6547372008-08-04 17:54:01 +0100303 if (test_and_set_bit(0, &wdt_open))
Jorge Boncompte [DTI2]38ff6fd2007-11-19 15:09:21 +0100304 return -EBUSY;
305 it8712f_wdt_enable();
Jorge Boncompte [DTI2]38ff6fd2007-11-19 15:09:21 +0100306 return nonseekable_open(inode, file);
307}
308
Alan Coxd6547372008-08-04 17:54:01 +0100309static int it8712f_wdt_release(struct inode *inode, struct file *file)
Jorge Boncompte [DTI2]38ff6fd2007-11-19 15:09:21 +0100310{
311 if (expect_close != 42) {
312 printk(KERN_WARNING NAME
313 ": watchdog device closed unexpectedly, will not"
314 " disable the watchdog timer\n");
315 } else if (!nowayout) {
316 it8712f_wdt_disable();
317 }
318 expect_close = 0;
Alan Coxd6547372008-08-04 17:54:01 +0100319 clear_bit(0, &wdt_open);
Jorge Boncompte [DTI2]38ff6fd2007-11-19 15:09:21 +0100320
321 return 0;
322}
323
Jan Engelhardtb47a1662008-01-22 20:48:10 +0100324static const struct file_operations it8712f_wdt_fops = {
Jorge Boncompte [DTI2]38ff6fd2007-11-19 15:09:21 +0100325 .owner = THIS_MODULE,
326 .llseek = no_llseek,
327 .write = it8712f_wdt_write,
Alan Coxd6547372008-08-04 17:54:01 +0100328 .unlocked_ioctl = it8712f_wdt_ioctl,
Jorge Boncompte [DTI2]38ff6fd2007-11-19 15:09:21 +0100329 .open = it8712f_wdt_open,
330 .release = it8712f_wdt_release,
331};
332
333static struct miscdevice it8712f_wdt_miscdev = {
334 .minor = WATCHDOG_MINOR,
335 .name = "watchdog",
336 .fops = &it8712f_wdt_fops,
337};
338
Alan Coxd6547372008-08-04 17:54:01 +0100339static int __init it8712f_wdt_find(unsigned short *address)
Jorge Boncompte [DTI2]38ff6fd2007-11-19 15:09:21 +0100340{
341 int err = -ENODEV;
342 int chip_type;
343
344 superio_enter();
345 chip_type = superio_inw(DEVID);
346 if (chip_type != IT8712F_DEVID)
347 goto exit;
348
349 superio_select(LDN_GAME);
350 superio_outb(1, ACT_REG);
351 if (!(superio_inb(ACT_REG) & 0x01)) {
352 printk(KERN_ERR NAME ": Device not activated, skipping\n");
353 goto exit;
354 }
355
356 *address = superio_inw(BASE_REG);
357 if (*address == 0) {
358 printk(KERN_ERR NAME ": Base address not set, skipping\n");
359 goto exit;
360 }
361
362 err = 0;
Andrew Paprocki5e699602008-02-10 22:11:15 -0500363 revision = superio_inb(DEVREV) & 0x0f;
364
365 /* Later revisions have 16-bit values per datasheet 0.9.1 */
366 if (revision >= 0x08)
367 max_units = 65535;
368
369 if (margin > (max_units * 60))
370 margin = (max_units * 60);
371
372 printk(KERN_INFO NAME ": Found IT%04xF chip revision %d - "
Jorge Boncompte [DTI2]38ff6fd2007-11-19 15:09:21 +0100373 "using DogFood address 0x%x\n",
Andrew Paprocki5e699602008-02-10 22:11:15 -0500374 chip_type, revision, *address);
Jorge Boncompte [DTI2]38ff6fd2007-11-19 15:09:21 +0100375
376exit:
377 superio_exit();
378 return err;
379}
380
Alan Coxd6547372008-08-04 17:54:01 +0100381static int __init it8712f_wdt_init(void)
Jorge Boncompte [DTI2]38ff6fd2007-11-19 15:09:21 +0100382{
383 int err = 0;
384
385 spin_lock_init(&io_lock);
386
387 if (it8712f_wdt_find(&address))
388 return -ENODEV;
389
390 if (!request_region(address, 1, "IT8712F Watchdog")) {
391 printk(KERN_WARNING NAME ": watchdog I/O region busy\n");
392 return -EBUSY;
393 }
394
395 it8712f_wdt_disable();
396
Jorge Boncompte [DTI2]38ff6fd2007-11-19 15:09:21 +0100397 err = register_reboot_notifier(&it8712f_wdt_notifier);
398 if (err) {
399 printk(KERN_ERR NAME ": unable to register reboot notifier\n");
400 goto out;
401 }
402
403 err = misc_register(&it8712f_wdt_miscdev);
404 if (err) {
405 printk(KERN_ERR NAME
406 ": cannot register miscdev on minor=%d (err=%d)\n",
407 WATCHDOG_MINOR, err);
408 goto reboot_out;
409 }
410
411 return 0;
412
413
414reboot_out:
415 unregister_reboot_notifier(&it8712f_wdt_notifier);
416out:
417 release_region(address, 1);
418 return err;
419}
420
Alan Coxd6547372008-08-04 17:54:01 +0100421static void __exit it8712f_wdt_exit(void)
Jorge Boncompte [DTI2]38ff6fd2007-11-19 15:09:21 +0100422{
423 misc_deregister(&it8712f_wdt_miscdev);
424 unregister_reboot_notifier(&it8712f_wdt_notifier);
425 release_region(address, 1);
426}
427
428module_init(it8712f_wdt_init);
429module_exit(it8712f_wdt_exit);