4 * (c) Copyright 2006 Marcus Junker <junker@anduras.de>
6 * Based on w83627hf_wdt.c advantechwdt.c which is based on wdt.c.
7 * Original copyright messages:
9 * (c) Copyright 2003 Pádraig Brady <P@draigBrady.com>
11 * (c) Copyright 2000-2001 Marek Michalkiewicz <marekm@linux.org.pl>
13 * (c) Copyright 1996 Alan Cox <alan@redhat.com>, All Rights Reserved.
14 * http://www.redhat.com
16 * This program is free software; you can redistribute it and/or
17 * modify it under the terms of the GNU General Public License
18 * as published by the Free Software Foundation; either version
19 * 2 of the License, or (at your option) any later version.
21 * Neither Marcus Junker nor ANDURAS AG admit liability nor provide
22 * warranty for any of this software. This material is provided
23 * "AS-IS" and at no charge.
26 #include <linux/module.h>
27 #include <linux/moduleparam.h>
28 #include <linux/types.h>
29 #include <linux/miscdevice.h>
30 #include <linux/watchdog.h>
32 #include <linux/ioport.h>
33 #include <linux/notifier.h>
34 #include <linux/reboot.h>
35 #include <linux/init.h>
36 #include <linux/spinlock.h>
39 #include <asm/uaccess.h>
40 #include <asm/system.h>
42 #define WATCHDOG_NAME "w83697hf WDT"
43 #define PFX WATCHDOG_NAME ": "
44 #define WATCHDOG_TIMEOUT 60 /* 60 sec default timeout */
46 static unsigned long wdt_is_open;
47 static char expect_close;
48 static spinlock_t io_lock;
50 /* You must set this - there is no sane way to probe for this board. */
51 static int wdt_io = 0x2E;
52 module_param(wdt_io, int, 0);
53 MODULE_PARM_DESC(wdt_io, "w83697hf WDT io port (default 0x2E)");
55 static int timeout = WATCHDOG_TIMEOUT; /* in seconds */
56 module_param(timeout, int, 0);
57 MODULE_PARM_DESC(timeout, "Watchdog timeout in seconds. 1<= timeout <=63, default=" __MODULE_STRING(WATCHDOG_TIMEOUT) ".");
59 static int nowayout = WATCHDOG_NOWAYOUT;
60 module_param(nowayout, int, 0);
61 MODULE_PARM_DESC(nowayout, "Watchdog cannot be stopped once started (default=CONFIG_WATCHDOG_NOWAYOUT)");
67 #define WDT_EFER (wdt_io+0) /* Extended Function Enable Registers */
68 #define WDT_EFIR (wdt_io+0) /* Extended Function Index Register (same as EFER) */
69 #define WDT_EFDR (WDT_EFIR+1) /* Extended Function Data Register */
72 w83697hf_select_wd_register(void)
74 outb_p(0x87, WDT_EFER); /* Enter extended function mode */
75 outb_p(0x87, WDT_EFER); /* Again according to manual */
77 outb_p(0x29, WDT_EFER); /* select CR29 */
78 outb_p(0x20, WDT_EFDR); /* select WDTO */
80 outb_p(0x07, WDT_EFER); /* point to logical device number reg */
81 outb_p(0x08, WDT_EFDR); /* select logical device 8 (GPIO2) */
82 outb_p(0x30, WDT_EFER); /* select CR30 */
83 outb_p(0x01, WDT_EFDR); /* set bit 0 to activate GPIO2 */
87 w83697hf_unselect_wd_register(void)
89 outb_p(0xAA, WDT_EFER); /* Leave extended function mode */
97 w83697hf_select_wd_register();
99 outb_p(0xF3, WDT_EFER); /* Select CRF3 */
101 t=inb_p(WDT_EFDR); /* read CRF3 */
103 printk (KERN_INFO PFX "Watchdog already running. Resetting timeout to %d sec\n", timeout);
104 outb_p(timeout, WDT_EFDR); /* Write back to CRF3 */
106 outb_p(0xF4, WDT_EFER); /* Select CRF4 */
107 t=inb_p(WDT_EFDR); /* read CRF4 */
108 t&=~0x0C; /* set second mode & disable keyboard turning off watchdog */
109 outb_p(t, WDT_EFDR); /* Write back to CRF4 */
111 w83697hf_unselect_wd_register();
115 wdt_ctrl(int timeout)
119 w83697hf_select_wd_register();
121 outb_p(0xF4, WDT_EFER); /* Select CRF4 */
122 outb_p(timeout, WDT_EFDR); /* Write Timeout counter to CRF4 */
124 w83697hf_unselect_wd_register();
126 spin_unlock(&io_lock);
144 wdt_set_heartbeat(int t)
146 if ((t < 1) || (t > 63))
154 wdt_write(struct file *file, const char __user *buf, size_t count, loff_t *ppos)
162 for (i = 0; i != count; i++) {
164 if (get_user(c, buf+i))
176 wdt_ioctl(struct inode *inode, struct file *file, unsigned int cmd,
179 void __user *argp = (void __user *)arg;
180 int __user *p = argp;
182 static struct watchdog_info ident = {
183 .options = WDIOF_KEEPALIVEPING | WDIOF_SETTIMEOUT | WDIOF_MAGICCLOSE,
184 .firmware_version = 1,
185 .identity = "W83697HF WDT",
189 case WDIOC_GETSUPPORT:
190 if (copy_to_user(argp, &ident, sizeof(ident)))
194 case WDIOC_GETSTATUS:
195 case WDIOC_GETBOOTSTATUS:
196 return put_user(0, p);
198 case WDIOC_KEEPALIVE:
202 case WDIOC_SETTIMEOUT:
203 if (get_user(new_timeout, p))
205 if (wdt_set_heartbeat(new_timeout))
210 case WDIOC_GETTIMEOUT:
211 return put_user(timeout, p);
213 case WDIOC_SETOPTIONS:
215 int options, retval = -EINVAL;
217 if (get_user(options, p))
220 if (options & WDIOS_DISABLECARD) {
225 if (options & WDIOS_ENABLECARD) {
240 wdt_open(struct inode *inode, struct file *file)
242 if (test_and_set_bit(0, &wdt_is_open))
249 return nonseekable_open(inode, file);
253 wdt_close(struct inode *inode, struct file *file)
255 if (expect_close == 42) {
258 printk (KERN_CRIT PFX "Unexpected close, not stopping watchdog!\n");
262 clear_bit(0, &wdt_is_open);
267 * Notifier for system down
271 wdt_notify_sys(struct notifier_block *this, unsigned long code,
274 if (code == SYS_DOWN || code == SYS_HALT) {
275 /* Turn the WDT off */
285 static struct file_operations wdt_fops = {
286 .owner = THIS_MODULE,
291 .release = wdt_close,
294 static struct miscdevice wdt_miscdev = {
295 .minor = WATCHDOG_MINOR,
301 * The WDT needs to learn about soft shutdowns in order to
302 * turn the timebomb registers off.
305 static struct notifier_block wdt_notifier = {
306 .notifier_call = wdt_notify_sys,
314 spin_lock_init(&io_lock);
316 printk (KERN_INFO "WDT driver for the Winbond(TM) W83697HF Super I/O chip initialising.\n");
318 if (wdt_set_heartbeat(timeout)) {
319 wdt_set_heartbeat(WATCHDOG_TIMEOUT);
320 printk (KERN_INFO PFX "timeout value must be 1<=timeout<=63, using %d\n",
324 if (!request_region(wdt_io, 2, WATCHDOG_NAME)) {
325 printk (KERN_ERR PFX "I/O address 0x%04x already in use\n",
333 ret = register_reboot_notifier(&wdt_notifier);
335 printk (KERN_ERR PFX "cannot register reboot notifier (err=%d)\n",
340 ret = misc_register(&wdt_miscdev);
342 printk (KERN_ERR PFX "cannot register miscdev on minor=%d (err=%d)\n",
343 WATCHDOG_MINOR, ret);
347 printk (KERN_INFO PFX "initialized. timeout=%d sec (nowayout=%d)\n",
353 unregister_reboot_notifier(&wdt_notifier);
355 release_region(wdt_io, 2);
362 misc_deregister(&wdt_miscdev);
363 unregister_reboot_notifier(&wdt_notifier);
364 release_region(wdt_io, 2);
367 module_init(wdt_init);
368 module_exit(wdt_exit);
370 MODULE_LICENSE("GPL");
371 MODULE_AUTHOR("Marcus Junker <junker@anduras.de>");
372 MODULE_DESCRIPTION("w83697hf WDT driver");
373 MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR);