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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>
33
34#include <asm/uaccess.h>
35#include <asm/io.h>
36
37#define NAME "it8712f_wdt"
38
39MODULE_AUTHOR("Jorge Boncompte - DTI2 <jorge@dti2.net>");
40MODULE_DESCRIPTION("IT8712F Watchdog Driver");
41MODULE_LICENSE("GPL");
42MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR);
43
Andrew Paprocki5e699602008-02-10 22:11:15 -050044static int max_units = 255;
Jorge Boncompte [DTI2]38ff6fd2007-11-19 15:09:21 +010045static int margin = 60; /* in seconds */
46module_param(margin, int, 0);
47MODULE_PARM_DESC(margin, "Watchdog margin in seconds");
48
49static int nowayout = WATCHDOG_NOWAYOUT;
50module_param(nowayout, int, 0);
51MODULE_PARM_DESC(nowayout, "Disable watchdog shutdown on close");
52
53static struct semaphore it8712f_wdt_sem;
54static unsigned expect_close;
55static spinlock_t io_lock;
Andrew Paprocki5e699602008-02-10 22:11:15 -050056static unsigned char revision;
Jorge Boncompte [DTI2]38ff6fd2007-11-19 15:09:21 +010057
58/* Dog Food address - We use the game port address */
59static 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
89static int
90superio_inb(int reg)
91{
92 outb(reg, REG);
93 return inb(VAL);
94}
95
96static void
97superio_outb(int val, int reg)
98{
99 outb(reg, REG);
100 outb(val, VAL);
101}
102
103static int
104superio_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
114static inline void
115superio_select(int ldn)
116{
117 outb(LDN, REG);
118 outb(ldn, VAL);
119}
120
121static inline void
122superio_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
131static inline void
132superio_exit(void)
133{
134 outb(0x02, REG);
135 outb(0x02, VAL);
136 spin_unlock(&io_lock);
137}
138
139static inline void
140it8712f_wdt_ping(void)
141{
142 inb(address);
143}
144
145static void
146it8712f_wdt_update_margin(void)
147{
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
168static int
169it8712f_wdt_get_status(void)
170{
171 if (superio_inb(WDT_CONTROL) & 0x01)
172 return WDIOF_CARDRESET;
173 else
174 return 0;
Jorge Boncompte [DTI2]38ff6fd2007-11-19 15:09:21 +0100175}
176
177static void
178it8712f_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
193static void
194it8712f_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);
Andrew Paprockicc1020f2008-04-02 02:43:19 -0400203 if (revision >= 0x08)
204 superio_outb(0, WDT_TIMEOUT + 1);
Jorge Boncompte [DTI2]38ff6fd2007-11-19 15:09:21 +0100205 superio_outb(0, WDT_TIMEOUT);
206
207 superio_exit();
208}
209
210static int
211it8712f_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
221static struct notifier_block it8712f_wdt_notifier = {
222 .notifier_call = it8712f_wdt_notify,
223};
224
225static ssize_t
226it8712f_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
248static int
249it8712f_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 };
Andrew Paprocki5e699602008-02-10 22:11:15 -0500259 int value;
Jorge Boncompte [DTI2]38ff6fd2007-11-19 15:09:21 +0100260
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:
Andrew Paprocki5e699602008-02-10 22:11:15 -0500269 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);
Jorge Boncompte [DTI2]38ff6fd2007-11-19 15:09:21 +0100277 case WDIOC_GETBOOTSTATUS:
278 return put_user(0, p);
279 case WDIOC_KEEPALIVE:
280 it8712f_wdt_ping();
281 return 0;
282 case WDIOC_SETTIMEOUT:
Andrew Paprocki5e699602008-02-10 22:11:15 -0500283 if (get_user(value, p))
Jorge Boncompte [DTI2]38ff6fd2007-11-19 15:09:21 +0100284 return -EFAULT;
Andrew Paprocki5e699602008-02-10 22:11:15 -0500285 if (value < 1)
Jorge Boncompte [DTI2]38ff6fd2007-11-19 15:09:21 +0100286 return -EINVAL;
Andrew Paprocki5e699602008-02-10 22:11:15 -0500287 if (value > (max_units * 60))
288 return -EINVAL;
289 margin = value;
Jorge Boncompte [DTI2]38ff6fd2007-11-19 15:09:21 +0100290 superio_enter();
291 superio_select(LDN_GPIO);
292
293 it8712f_wdt_update_margin();
294
295 superio_exit();
296 it8712f_wdt_ping();
Andrew Paprocki5e699602008-02-10 22:11:15 -0500297 /* Fall through */
Jorge Boncompte [DTI2]38ff6fd2007-11-19 15:09:21 +0100298 case WDIOC_GETTIMEOUT:
299 if (put_user(margin, p))
300 return -EFAULT;
301 return 0;
302 }
303}
304
305static int
306it8712f_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
316static int
317it8712f_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
Jan Engelhardtb47a1662008-01-22 20:48:10 +0100332static const struct file_operations it8712f_wdt_fops = {
Jorge Boncompte [DTI2]38ff6fd2007-11-19 15:09:21 +0100333 .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
341static struct miscdevice it8712f_wdt_miscdev = {
342 .minor = WATCHDOG_MINOR,
343 .name = "watchdog",
344 .fops = &it8712f_wdt_fops,
345};
346
347static int __init
348it8712f_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;
Andrew Paprocki5e699602008-02-10 22:11:15 -0500372 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 - "
Jorge Boncompte [DTI2]38ff6fd2007-11-19 15:09:21 +0100382 "using DogFood address 0x%x\n",
Andrew Paprocki5e699602008-02-10 22:11:15 -0500383 chip_type, revision, *address);
Jorge Boncompte [DTI2]38ff6fd2007-11-19 15:09:21 +0100384
385exit:
386 superio_exit();
387 return err;
388}
389
390static int __init
391it8712f_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
426reboot_out:
427 unregister_reboot_notifier(&it8712f_wdt_notifier);
428out:
429 release_region(address, 1);
430 return err;
431}
432
433static void __exit
434it8712f_wdt_exit(void)
435{
436 misc_deregister(&it8712f_wdt_miscdev);
437 unregister_reboot_notifier(&it8712f_wdt_notifier);
438 release_region(address, 1);
439}
440
441module_init(it8712f_wdt_init);
442module_exit(it8712f_wdt_exit);