2 * w83697hf/hg WDT driver
4 * (c) Copyright 2006 Samuel Tardieu <sam@rfc1149.net>
5 * (c) Copyright 2006 Marcus Junker <junker@anduras.de>
7 * Based on w83627hf_wdt.c which is based on advantechwdt.c
8 * which is based on wdt.c.
9 * Original copyright messages:
11 * (c) Copyright 2003 Pádraig Brady <P@draigBrady.com>
13 * (c) Copyright 2000-2001 Marek Michalkiewicz <marekm@linux.org.pl>
15 * (c) Copyright 1996 Alan Cox <alan@redhat.com>, All Rights Reserved.
16 * http://www.redhat.com
18 * This program is free software; you can redistribute it and/or
19 * modify it under the terms of the GNU General Public License
20 * as published by the Free Software Foundation; either version
21 * 2 of the License, or (at your option) any later version.
23 * Neither Marcus Junker nor ANDURAS AG admit liability nor provide
24 * warranty for any of this software. This material is provided
25 * "AS-IS" and at no charge.
28 #include <linux/module.h>
29 #include <linux/moduleparam.h>
30 #include <linux/types.h>
31 #include <linux/miscdevice.h>
32 #include <linux/watchdog.h>
34 #include <linux/ioport.h>
35 #include <linux/notifier.h>
36 #include <linux/reboot.h>
37 #include <linux/init.h>
38 #include <linux/spinlock.h>
41 #include <asm/uaccess.h>
42 #include <asm/system.h>
44 #define WATCHDOG_NAME "w83697hf/hg WDT"
45 #define PFX WATCHDOG_NAME ": "
46 #define WATCHDOG_TIMEOUT 60 /* 60 sec default timeout */
48 static unsigned long wdt_is_open;
49 static char expect_close;
50 static DEFINE_SPINLOCK(io_lock);
52 /* You must set this - there is no sane way to probe for this board. */
53 static int wdt_io = 0x2e;
54 module_param(wdt_io, int, 0);
55 MODULE_PARM_DESC(wdt_io, "w83697hf/hg WDT io port (default 0x2e, 0 = autodetect)");
57 static int timeout = WATCHDOG_TIMEOUT; /* in seconds */
58 module_param(timeout, int, 0);
59 MODULE_PARM_DESC(timeout, "Watchdog timeout in seconds. 1<= timeout <=255, default=" __MODULE_STRING(WATCHDOG_TIMEOUT) ".");
61 static int nowayout = WATCHDOG_NOWAYOUT;
62 module_param(nowayout, int, 0);
63 MODULE_PARM_DESC(nowayout, "Watchdog cannot be stopped once started (default=" __MODULE_STRING(WATCHDOG_NOWAYOUT) ")");
69 #define W83697HF_EFER (wdt_io+0) /* Extended Function Enable Register */
70 #define W83697HF_EFIR (wdt_io+0) /* Extended Function Index Register (same as EFER) */
71 #define W83697HF_EFDR (wdt_io+1) /* Extended Function Data Register */
76 outb_p(0x87, W83697HF_EFER); /* Enter extended function mode */
77 outb_p(0x87, W83697HF_EFER); /* Again according to manual */
83 outb_p(0xAA, W83697HF_EFER); /* Leave extended function mode */
87 * The three functions w83697hf_get_reg(), w83697hf_set_reg() and
88 * w83697hf_write_timeout() must be called with the device unlocked.
92 w83697hf_get_reg(unsigned char reg)
94 outb_p(reg, W83697HF_EFIR);
95 return inb_p(W83697HF_EFDR);
99 w83697hf_set_reg(unsigned char reg, unsigned char data)
101 outb_p(reg, W83697HF_EFIR);
102 outb_p(data, W83697HF_EFDR);
106 w83697hf_write_timeout(int timeout)
108 w83697hf_set_reg(0xF4, timeout); /* Write Timeout counter to CRF4 */
112 w83697hf_select_wdt(void)
115 w83697hf_set_reg(0x07, 0x08); /* Switch to logic device 8 (GPIO2) */
119 w83697hf_deselect_wdt(void)
129 w83697hf_select_wdt();
131 bbuf = w83697hf_get_reg(0x29);
134 w83697hf_set_reg(0x29, bbuf); /* Set pin 119 to WDTO# mode (= CR29, WDT0) */
136 bbuf = w83697hf_get_reg(0xF3);
138 w83697hf_set_reg(0xF3, bbuf); /* Count mode is seconds */
140 w83697hf_deselect_wdt();
147 w83697hf_select_wdt();
149 w83697hf_write_timeout(timeout);
151 w83697hf_deselect_wdt();
152 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);
172 w83697hf_select_wdt();
174 w83697hf_set_reg(0x30, 0); /* Disable timer */
175 w83697hf_write_timeout(0);
177 w83697hf_deselect_wdt();
178 spin_unlock(&io_lock);
182 wdt_set_heartbeat(int t)
184 if ((t < 1) || (t > 255))
192 wdt_write(struct file *file, const char __user *buf, size_t count, loff_t *ppos)
200 for (i = 0; i != count; i++) {
202 if (get_user(c, buf+i))
214 wdt_ioctl(struct inode *inode, struct file *file, unsigned int cmd,
217 void __user *argp = (void __user *)arg;
218 int __user *p = argp;
220 static struct watchdog_info ident = {
221 .options = WDIOF_KEEPALIVEPING | WDIOF_SETTIMEOUT | WDIOF_MAGICCLOSE,
222 .firmware_version = 1,
223 .identity = "W83697HF WDT",
227 case WDIOC_GETSUPPORT:
228 if (copy_to_user(argp, &ident, sizeof(ident)))
232 case WDIOC_GETSTATUS:
233 case WDIOC_GETBOOTSTATUS:
234 return put_user(0, p);
236 case WDIOC_KEEPALIVE:
240 case WDIOC_SETTIMEOUT:
241 if (get_user(new_timeout, p))
243 if (wdt_set_heartbeat(new_timeout))
248 case WDIOC_GETTIMEOUT:
249 return put_user(timeout, p);
251 case WDIOC_SETOPTIONS:
253 int options, retval = -EINVAL;
255 if (get_user(options, p))
258 if (options & WDIOS_DISABLECARD) {
263 if (options & WDIOS_ENABLECARD) {
278 wdt_open(struct inode *inode, struct file *file)
280 if (test_and_set_bit(0, &wdt_is_open))
287 return nonseekable_open(inode, file);
291 wdt_close(struct inode *inode, struct file *file)
293 if (expect_close == 42) {
296 printk (KERN_CRIT PFX "Unexpected close, not stopping watchdog!\n");
300 clear_bit(0, &wdt_is_open);
305 * Notifier for system down
309 wdt_notify_sys(struct notifier_block *this, unsigned long code,
312 if (code == SYS_DOWN || code == SYS_HALT) {
313 /* Turn the WDT off */
323 static const struct file_operations wdt_fops = {
324 .owner = THIS_MODULE,
329 .release = wdt_close,
332 static struct miscdevice wdt_miscdev = {
333 .minor = WATCHDOG_MINOR,
339 * The WDT needs to learn about soft shutdowns in order to
340 * turn the timebomb registers off.
343 static struct notifier_block wdt_notifier = {
344 .notifier_call = wdt_notify_sys,
348 w83697hf_check_wdt(void)
350 if (!request_region(wdt_io, 2, WATCHDOG_NAME)) {
351 printk (KERN_ERR PFX "I/O address 0x%x already in use\n", wdt_io);
355 printk (KERN_DEBUG PFX "Looking for watchdog at address 0x%x\n", wdt_io);
357 if (w83697hf_get_reg(0x20) == 0x60) {
358 printk (KERN_INFO PFX "watchdog found at address 0x%x\n", wdt_io);
362 w83697hf_lock(); /* Reprotect in case it was a compatible device */
364 printk (KERN_INFO PFX "watchdog not found at address 0x%x\n", wdt_io);
365 release_region(wdt_io, 2);
369 static int w83697hf_ioports[] = { 0x2e, 0x4e, 0x00 };
374 int ret, i, found = 0;
376 printk (KERN_INFO PFX "WDT driver for W83697HF/HG initializing\n");
379 /* we will autodetect the W83697HF/HG watchdog */
380 for (i = 0; ((!found) && (w83697hf_ioports[i] != 0)); i++) {
381 wdt_io = w83697hf_ioports[i];
382 if (!w83697hf_check_wdt())
386 if (!w83697hf_check_wdt())
391 printk (KERN_ERR PFX "No W83697HF/HG could be found\n");
397 wdt_disable(); /* Disable watchdog until first use */
399 if (wdt_set_heartbeat(timeout)) {
400 wdt_set_heartbeat(WATCHDOG_TIMEOUT);
401 printk (KERN_INFO PFX "timeout value must be 1<=timeout<=255, using %d\n",
405 ret = register_reboot_notifier(&wdt_notifier);
407 printk (KERN_ERR PFX "cannot register reboot notifier (err=%d)\n",
412 ret = misc_register(&wdt_miscdev);
414 printk (KERN_ERR PFX "cannot register miscdev on minor=%d (err=%d)\n",
415 WATCHDOG_MINOR, ret);
419 printk (KERN_INFO PFX "initialized. timeout=%d sec (nowayout=%d)\n",
425 unregister_reboot_notifier(&wdt_notifier);
427 release_region(wdt_io, 2);
434 misc_deregister(&wdt_miscdev);
435 unregister_reboot_notifier(&wdt_notifier);
436 release_region(wdt_io, 2);
439 module_init(wdt_init);
440 module_exit(wdt_exit);
442 MODULE_LICENSE("GPL");
443 MODULE_AUTHOR("Marcus Junker <junker@anduras.de>, Samuel Tardieu <sam@rfc1149.net>");
444 MODULE_DESCRIPTION("w83697hf/hg WDT driver");
445 MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR);