2 * IT8712F "Smart Guardian" Watchdog support
4 * Copyright (c) 2006-2007 Jorge Boncompte - DTI2 <jorge@dti2.net>
6 * Based on info and code taken from:
8 * drivers/char/watchdog/scx200_wdt.c
10 * IT8712F EC-LPC I/O Preliminary Specification 0.8.2
11 * IT8712F EC-LPC I/O Preliminary Specification 0.9.3
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.
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.
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>
31 #include <linux/pci.h>
32 #include <linux/spinlock.h>
33 #include <linux/uaccess.h>
36 #define NAME "it8712f_wdt"
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
);
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");
48 static int nowayout
= WATCHDOG_NOWAYOUT
;
49 module_param(nowayout
, int, 0);
50 MODULE_PARM_DESC(nowayout
, "Disable watchdog shutdown on close");
52 static unsigned long wdt_open
;
53 static unsigned expect_close
;
54 static spinlock_t io_lock
;
55 static unsigned char revision
;
57 /* Dog Food address - We use the game port address */
58 static unsigned short address
;
60 #define REG 0x2e /* The register to read/write */
61 #define VAL 0x2f /* The value to read/write */
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 */
69 #define IT8712F_DEVID 0x8712
71 #define LDN_GPIO 0x07 /* GPIO and Watch Dog Timer */
72 #define LDN_GAME 0x09 /* Game Port */
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 */
78 #define WDT_RESET_GAME 0x10
79 #define WDT_RESET_KBD 0x20
80 #define WDT_RESET_MOUSE 0x40
81 #define WDT_RESET_CIR 0x80
83 #define WDT_UNIT_SEC 0x80 /* If 0 in MINUTES */
85 #define WDT_OUT_PWROK 0x10
86 #define WDT_OUT_KRST 0x40
88 static int superio_inb(int reg
)
94 static void superio_outb(int val
, int reg
)
100 static int superio_inw(int reg
)
110 static inline void superio_select(int ldn
)
116 static inline void superio_enter(void)
125 static inline void superio_exit(void)
129 spin_unlock(&io_lock
);
132 static inline void it8712f_wdt_ping(void)
137 static void it8712f_wdt_update_margin(void)
139 int config
= WDT_OUT_KRST
| WDT_OUT_PWROK
;
142 /* Switch to minutes precision if the configured margin
143 * value does not fit within the register width.
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
);
150 printk(KERN_INFO NAME
": timer margin %d minutes\n", units
);
152 superio_outb(config
, WDT_CONFIG
);
154 if (revision
>= 0x08)
155 superio_outb(units
>> 8, WDT_TIMEOUT
+ 1);
156 superio_outb(units
, WDT_TIMEOUT
);
159 static int it8712f_wdt_get_status(void)
161 if (superio_inb(WDT_CONTROL
) & 0x01)
162 return WDIOF_CARDRESET
;
167 static void it8712f_wdt_enable(void)
169 printk(KERN_DEBUG NAME
": enabling watchdog timer\n");
171 superio_select(LDN_GPIO
);
173 superio_outb(WDT_RESET_GAME
, WDT_CONTROL
);
175 it8712f_wdt_update_margin();
182 static void it8712f_wdt_disable(void)
184 printk(KERN_DEBUG NAME
": disabling watchdog timer\n");
187 superio_select(LDN_GPIO
);
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
);
198 static int it8712f_wdt_notify(struct notifier_block
*this,
199 unsigned long code
, void *unused
)
201 if (code
== SYS_HALT
|| code
== SYS_POWER_OFF
)
203 it8712f_wdt_disable();
208 static struct notifier_block it8712f_wdt_notifier
= {
209 .notifier_call
= it8712f_wdt_notify
,
212 static ssize_t
it8712f_wdt_write(struct file
*file
, const char __user
*data
,
213 size_t len
, loff_t
*ppos
)
215 /* check for a magic close character */
222 for (i
= 0; i
< len
; ++i
) {
224 if (get_user(c
, data
+i
))
234 static long it8712f_wdt_ioctl(struct file
*file
, unsigned int cmd
,
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
,
249 case WDIOC_GETSUPPORT
:
250 if (copy_to_user(argp
, &ident
, sizeof(ident
)))
253 case WDIOC_GETSTATUS
:
255 superio_select(LDN_GPIO
);
257 value
= it8712f_wdt_get_status();
261 return put_user(value
, p
);
262 case WDIOC_GETBOOTSTATUS
:
263 return put_user(0, p
);
264 case WDIOC_KEEPALIVE
:
267 case WDIOC_SETTIMEOUT
:
268 if (get_user(value
, p
))
272 if (value
> (max_units
* 60))
276 superio_select(LDN_GPIO
);
278 it8712f_wdt_update_margin();
283 case WDIOC_GETTIMEOUT
:
284 if (put_user(margin
, p
))
290 static int it8712f_wdt_open(struct inode
*inode
, struct file
*file
)
292 /* only allow one at a time */
293 if (test_and_set_bit(0, &wdt_open
))
295 it8712f_wdt_enable();
296 return nonseekable_open(inode
, file
);
299 static int it8712f_wdt_release(struct inode
*inode
, struct file
*file
)
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();
309 clear_bit(0, &wdt_open
);
314 static const struct file_operations it8712f_wdt_fops
= {
315 .owner
= THIS_MODULE
,
317 .write
= it8712f_wdt_write
,
318 .unlocked_ioctl
= it8712f_wdt_ioctl
,
319 .open
= it8712f_wdt_open
,
320 .release
= it8712f_wdt_release
,
323 static struct miscdevice it8712f_wdt_miscdev
= {
324 .minor
= WATCHDOG_MINOR
,
326 .fops
= &it8712f_wdt_fops
,
329 static int __init
it8712f_wdt_find(unsigned short *address
)
335 chip_type
= superio_inw(DEVID
);
336 if (chip_type
!= IT8712F_DEVID
)
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");
346 *address
= superio_inw(BASE_REG
);
348 printk(KERN_ERR NAME
": Base address not set, skipping\n");
353 revision
= superio_inb(DEVREV
) & 0x0f;
355 /* Later revisions have 16-bit values per datasheet 0.9.1 */
356 if (revision
>= 0x08)
359 if (margin
> (max_units
* 60))
360 margin
= (max_units
* 60);
362 printk(KERN_INFO NAME
": Found IT%04xF chip revision %d - "
363 "using DogFood address 0x%x\n",
364 chip_type
, revision
, *address
);
371 static int __init
it8712f_wdt_init(void)
375 spin_lock_init(&io_lock
);
377 if (it8712f_wdt_find(&address
))
380 if (!request_region(address
, 1, "IT8712F Watchdog")) {
381 printk(KERN_WARNING NAME
": watchdog I/O region busy\n");
385 it8712f_wdt_disable();
387 err
= register_reboot_notifier(&it8712f_wdt_notifier
);
389 printk(KERN_ERR NAME
": unable to register reboot notifier\n");
393 err
= misc_register(&it8712f_wdt_miscdev
);
396 ": cannot register miscdev on minor=%d (err=%d)\n",
397 WATCHDOG_MINOR
, err
);
405 unregister_reboot_notifier(&it8712f_wdt_notifier
);
407 release_region(address
, 1);
411 static void __exit
it8712f_wdt_exit(void)
413 misc_deregister(&it8712f_wdt_miscdev
);
414 unregister_reboot_notifier(&it8712f_wdt_notifier
);
415 release_region(address
, 1);
418 module_init(it8712f_wdt_init
);
419 module_exit(it8712f_wdt_exit
);