2 * w83697hf/hg WDT driver
4 * (c) Copyright 2006 Marcus Junker <junker@anduras.de>
6 * Based on w83627hf_wdt.c which is based on advantechwdt.c
7 * which is based on wdt.c.
8 * Original copyright messages:
10 * (c) Copyright 2003 Pádraig Brady <P@draigBrady.com>
12 * (c) Copyright 2000-2001 Marek Michalkiewicz <marekm@linux.org.pl>
14 * (c) Copyright 1996 Alan Cox <alan@redhat.com>, All Rights Reserved.
15 * http://www.redhat.com
17 * This program is free software; you can redistribute it and/or
18 * modify it under the terms of the GNU General Public License
19 * as published by the Free Software Foundation; either version
20 * 2 of the License, or (at your option) any later version.
22 * Neither Marcus Junker nor ANDURAS AG admit liability nor provide
23 * warranty for any of this software. This material is provided
24 * "AS-IS" and at no charge.
27 #include <linux/module.h>
28 #include <linux/moduleparam.h>
29 #include <linux/types.h>
30 #include <linux/miscdevice.h>
31 #include <linux/watchdog.h>
33 #include <linux/ioport.h>
34 #include <linux/notifier.h>
35 #include <linux/reboot.h>
36 #include <linux/init.h>
37 #include <linux/spinlock.h>
40 #include <asm/uaccess.h>
41 #include <asm/system.h>
43 #define WATCHDOG_NAME "w83697hf/hg WDT"
44 #define PFX WATCHDOG_NAME ": "
45 #define WATCHDOG_TIMEOUT 60 /* 60 sec default timeout */
47 static unsigned long wdt_is_open;
48 static char expect_close;
49 static spinlock_t io_lock;
51 /* You must set this - there is no sane way to probe for this board. */
52 static int wdt_io = 0x2e;
53 module_param(wdt_io, int, 0);
54 MODULE_PARM_DESC(wdt_io, "w83697hf/hg WDT io port (default 0x2e, 0 = autodetect)");
56 static int timeout = WATCHDOG_TIMEOUT; /* in seconds */
57 module_param(timeout, int, 0);
58 MODULE_PARM_DESC(timeout, "Watchdog timeout in seconds. 1<= timeout <=255, default=" __MODULE_STRING(WATCHDOG_TIMEOUT) ".");
60 static int nowayout = WATCHDOG_NOWAYOUT;
61 module_param(nowayout, int, 0);
62 MODULE_PARM_DESC(nowayout, "Watchdog cannot be stopped once started (default=CONFIG_WATCHDOG_NOWAYOUT)");
68 #define W83697HF_EFER (wdt_io+0) /* Extended Function Enable Register */
69 #define W83697HF_EFIR (wdt_io+0) /* Extended Function Index Register (same as EFER) */
70 #define W83697HF_EFDR (wdt_io+1) /* Extended Function Data Register */
75 outb_p(0x87, W83697HF_EFER); /* Enter extended function mode */
76 outb_p(0x87, W83697HF_EFER); /* Again according to manual */
82 outb_p(0xAA, W83697HF_EFER); /* Leave extended function mode */
86 * The three functions w83697hf_get_reg(), w83697hf_set_reg() and
87 * w83697hf_write_timeout() must be called with the device unlocked.
91 w83697hf_get_reg(unsigned char reg)
93 outb_p(reg, W83697HF_EFIR);
94 return inb_p(W83697HF_EFDR);
98 w83697hf_set_reg(unsigned char reg, unsigned char data)
100 outb_p(reg, W83697HF_EFIR);
101 outb_p(data, W83697HF_EFDR);
105 w83697hf_write_timeout(int timeout)
107 w83697hf_set_reg(0xF4, timeout); /* Write Timeout counter to CRF4 */
111 w83697hf_select_wdt(void)
114 w83697hf_set_reg(0x07, 0x08); /* Switch to logic device 8 (GPIO2) */
118 w83697hf_deselect_wdt(void)
128 w83697hf_select_wdt();
130 bbuf = w83697hf_get_reg(0x29);
133 w83697hf_set_reg(0x29, bbuf); /* Set pin 119 to WDTO# mode (= CR29, WDT0) */
135 bbuf = w83697hf_get_reg(0xF3);
137 w83697hf_set_reg(0xF3, bbuf); /* Count mode is seconds */
139 w83697hf_deselect_wdt();
146 w83697hf_select_wdt();
148 w83697hf_write_timeout(timeout);
150 w83697hf_deselect_wdt();
151 spin_unlock(&io_lock);
159 w83697hf_select_wdt();
161 w83697hf_write_timeout(timeout);
162 w83697hf_set_reg(0x30, 1); /* Enable timer */
164 w83697hf_deselect_wdt();
165 spin_unlock(&io_lock);
173 w83697hf_select_wdt();
175 w83697hf_set_reg(0x30, 0); /* Disable timer */
176 w83697hf_write_timeout(0);
178 w83697hf_deselect_wdt();
179 spin_unlock(&io_lock);
184 wdt_set_heartbeat(int t)
186 if ((t < 1) || (t > 255))
194 wdt_write(struct file *file, const char __user *buf, size_t count, loff_t *ppos)
202 for (i = 0; i != count; i++) {
204 if (get_user(c, buf+i))
216 wdt_ioctl(struct inode *inode, struct file *file, unsigned int cmd,
219 void __user *argp = (void __user *)arg;
220 int __user *p = argp;
222 static struct watchdog_info ident = {
223 .options = WDIOF_KEEPALIVEPING | WDIOF_SETTIMEOUT | WDIOF_MAGICCLOSE,
224 .firmware_version = 1,
225 .identity = "W83697HF WDT",
229 case WDIOC_GETSUPPORT:
230 if (copy_to_user(argp, &ident, sizeof(ident)))
234 case WDIOC_GETSTATUS:
235 case WDIOC_GETBOOTSTATUS:
236 return put_user(0, p);
238 case WDIOC_KEEPALIVE:
242 case WDIOC_SETTIMEOUT:
243 if (get_user(new_timeout, p))
245 if (wdt_set_heartbeat(new_timeout))
250 case WDIOC_GETTIMEOUT:
251 return put_user(timeout, p);
253 case WDIOC_SETOPTIONS:
255 int options, retval = -EINVAL;
257 if (get_user(options, p))
260 if (options & WDIOS_DISABLECARD) {
265 if (options & WDIOS_ENABLECARD) {
280 wdt_open(struct inode *inode, struct file *file)
282 if (test_and_set_bit(0, &wdt_is_open))
289 return nonseekable_open(inode, file);
293 wdt_close(struct inode *inode, struct file *file)
295 if (expect_close == 42) {
298 printk (KERN_CRIT PFX "Unexpected close, not stopping watchdog!\n");
302 clear_bit(0, &wdt_is_open);
307 * Notifier for system down
311 wdt_notify_sys(struct notifier_block *this, unsigned long code,
314 if (code == SYS_DOWN || code == SYS_HALT) {
315 /* Turn the WDT off */
325 static struct file_operations wdt_fops = {
326 .owner = THIS_MODULE,
331 .release = wdt_close,
334 static struct miscdevice wdt_miscdev = {
335 .minor = WATCHDOG_MINOR,
341 * The WDT needs to learn about soft shutdowns in order to
342 * turn the timebomb registers off.
345 static struct notifier_block wdt_notifier = {
346 .notifier_call = wdt_notify_sys,
350 w83697hf_check_wdt(void)
352 if (!request_region(wdt_io, 2, WATCHDOG_NAME)) {
353 printk (KERN_ERR PFX "I/O address 0x%x already in use\n", wdt_io);
357 printk (KERN_DEBUG PFX "Looking for watchdog at address 0x%x\n", wdt_io);
359 if (w83697hf_get_reg(0x20) == 0x60) {
360 printk (KERN_INFO PFX "watchdog found at address 0x%x\n", wdt_io);
364 w83697hf_lock(); /* Reprotect in case it was a compatible device */
366 printk (KERN_INFO PFX "watchdog not found at address 0x%x\n", wdt_io);
367 release_region(wdt_io, 2);
376 spin_lock_init(&io_lock);
378 printk (KERN_INFO PFX "WDT driver for W83697HF/HG initializing\n");
380 autodetect = wdt_io == 0;
384 if (!w83697hf_check_wdt())
389 if (!w83697hf_check_wdt())
393 printk (KERN_ERR PFX "No W83697HF/HG could be found\n");
399 wdt_disable(); /* Disable watchdog until first use */
401 if (wdt_set_heartbeat(timeout)) {
402 wdt_set_heartbeat(WATCHDOG_TIMEOUT);
403 printk (KERN_INFO PFX "timeout value must be 1<=timeout<=255, using %d\n",
407 ret = register_reboot_notifier(&wdt_notifier);
409 printk (KERN_ERR PFX "cannot register reboot notifier (err=%d)\n",
414 ret = misc_register(&wdt_miscdev);
416 printk (KERN_ERR PFX "cannot register miscdev on minor=%d (err=%d)\n",
417 WATCHDOG_MINOR, ret);
421 printk (KERN_INFO PFX "initialized. timeout=%d sec (nowayout=%d)\n",
427 unregister_reboot_notifier(&wdt_notifier);
429 release_region(wdt_io, 2);
436 misc_deregister(&wdt_miscdev);
437 unregister_reboot_notifier(&wdt_notifier);
438 release_region(wdt_io, 2);
441 module_init(wdt_init);
442 module_exit(wdt_exit);
444 MODULE_LICENSE("GPL");
445 MODULE_AUTHOR("Marcus Junker <junker@anduras.de>");
446 MODULE_DESCRIPTION("w83697hf/hg WDT driver");
447 MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR);