2 * Advantech Single Board Computer WDT driver
4 * (c) Copyright 2000-2001 Marek Michalkiewicz <marekm@linux.org.pl>
6 * Based on acquirewdt.c which is based on wdt.c.
7 * Original copyright messages:
9 * (c) Copyright 1996 Alan Cox <alan@redhat.com>, All Rights Reserved.
10 * http://www.redhat.com
12 * This program is free software; you can redistribute it and/or
13 * modify it under the terms of the GNU General Public License
14 * as published by the Free Software Foundation; either version
15 * 2 of the License, or (at your option) any later version.
17 * Neither Alan Cox nor CymruNet Ltd. admit liability nor provide
18 * warranty for any of this software. This material is provided
19 * "AS-IS" and at no charge.
21 * (c) Copyright 1995 Alan Cox <alan@redhat.com>
23 * 14-Dec-2001 Matt Domsch <Matt_Domsch@dell.com>
24 * Added nowayout module option to override CONFIG_WATCHDOG_NOWAYOUT
26 * 16-Oct-2002 Rob Radez <rob@osinvestor.com>
27 * Clean up ioctls, clean up init + exit, add expect close support,
28 * add wdt_start and wdt_stop as parameters.
31 #include <linux/module.h>
32 #include <linux/moduleparam.h>
33 #include <linux/types.h>
34 #include <linux/miscdevice.h>
35 #include <linux/watchdog.h>
37 #include <linux/ioport.h>
38 #include <linux/notifier.h>
39 #include <linux/reboot.h>
40 #include <linux/init.h>
43 #include <asm/uaccess.h>
44 #include <asm/system.h>
46 #define WATCHDOG_NAME "Advantech WDT"
47 #define PFX WATCHDOG_NAME ": "
48 #define WATCHDOG_TIMEOUT 60 /* 60 sec default timeout */
50 static unsigned long advwdt_is_open;
51 static char adv_expect_close;
54 * You must set these - there is no sane way to probe for this board.
56 * To enable or restart, write the timeout value in seconds (1 to 63)
57 * to I/O port wdt_start. To disable, read I/O port wdt_stop.
58 * Both are 0x443 for most boards (tested on a PCA-6276VE-00B1), but
59 * check your manual (at least the PCA-6159 seems to be different -
60 * the manual says wdt_stop is 0x43, not 0x443).
61 * (0x43 is also a write-only control register for the 8254 timer!)
64 static int wdt_stop = 0x443;
65 module_param(wdt_stop, int, 0);
66 MODULE_PARM_DESC(wdt_stop, "Advantech WDT 'stop' io port (default 0x443)");
68 static int wdt_start = 0x443;
69 module_param(wdt_start, int, 0);
70 MODULE_PARM_DESC(wdt_start, "Advantech WDT 'start' io port (default 0x443)");
72 static int timeout = WATCHDOG_TIMEOUT; /* in seconds */
73 module_param(timeout, int, 0);
74 MODULE_PARM_DESC(timeout, "Watchdog timeout in seconds. 1<= timeout <=63, default=" __MODULE_STRING(WATCHDOG_TIMEOUT) ".");
76 #ifdef CONFIG_WATCHDOG_NOWAYOUT
77 static int nowayout = 1;
79 static int nowayout = 0;
82 module_param(nowayout, int, 0);
83 MODULE_PARM_DESC(nowayout, "Watchdog cannot be stopped once started (default=CONFIG_WATCHDOG_NOWAYOUT)");
92 /* Write a watchdog value */
93 outb_p(timeout, wdt_start);
103 advwdt_write(struct file *file, const char *buf, size_t count, loff_t *ppos)
105 /* Can't seek (pwrite) on this device */
106 if (ppos != &file->f_pos)
113 adv_expect_close = 0;
115 for (i = 0; i != count; i++) {
117 if (get_user(c, buf+i))
120 adv_expect_close = 42;
129 advwdt_ioctl(struct inode *inode, struct file *file, unsigned int cmd,
133 static struct watchdog_info ident = {
134 .options = WDIOF_KEEPALIVEPING | WDIOF_SETTIMEOUT | WDIOF_MAGICCLOSE,
135 .firmware_version = 1,
136 .identity = "Advantech WDT",
140 case WDIOC_GETSUPPORT:
141 if (copy_to_user((struct watchdog_info *)arg, &ident, sizeof(ident)))
145 case WDIOC_GETSTATUS:
146 case WDIOC_GETBOOTSTATUS:
147 return put_user(0, (int *)arg);
149 case WDIOC_KEEPALIVE:
153 case WDIOC_SETTIMEOUT:
154 if (get_user(new_timeout, (int *)arg))
156 if ((new_timeout < 1) || (new_timeout > 63))
158 timeout = new_timeout;
162 case WDIOC_GETTIMEOUT:
163 return put_user(timeout, (int *)arg);
165 case WDIOC_SETOPTIONS:
167 int options, retval = -EINVAL;
169 if (get_user(options, (int *)arg))
172 if (options & WDIOS_DISABLECARD) {
177 if (options & WDIOS_ENABLECARD) {
192 advwdt_open(struct inode *inode, struct file *file)
194 if (test_and_set_bit(0, &advwdt_is_open))
205 advwdt_close(struct inode *inode, struct file *file)
207 if (adv_expect_close == 42) {
210 printk(KERN_CRIT PFX "Unexpected close, not stopping watchdog!\n");
213 clear_bit(0, &advwdt_is_open);
214 adv_expect_close = 0;
219 * Notifier for system down
223 advwdt_notify_sys(struct notifier_block *this, unsigned long code,
226 if (code == SYS_DOWN || code == SYS_HALT) {
227 /* Turn the WDT off */
237 static struct file_operations advwdt_fops = {
238 .owner = THIS_MODULE,
240 .write = advwdt_write,
241 .ioctl = advwdt_ioctl,
243 .release = advwdt_close,
246 static struct miscdevice advwdt_miscdev = {
247 .minor = WATCHDOG_MINOR,
249 .fops = &advwdt_fops,
253 * The WDT needs to learn about soft shutdowns in order to
254 * turn the timebomb registers off.
257 static struct notifier_block advwdt_notifier = {
258 .notifier_call = advwdt_notify_sys,
266 printk(KERN_INFO "WDT driver for Advantech single board computer initialising.\n");
268 if (timeout < 1 || timeout > 63) {
269 timeout = WATCHDOG_TIMEOUT;
270 printk (KERN_INFO PFX "timeout value must be 1<=x<=63, using %d\n",
274 if (wdt_stop != wdt_start) {
275 if (!request_region(wdt_stop, 1, WATCHDOG_NAME)) {
276 printk (KERN_ERR PFX "I/O address 0x%04x already in use\n",
283 if (!request_region(wdt_start, 1, WATCHDOG_NAME)) {
284 printk (KERN_ERR PFX "I/O address 0x%04x already in use\n",
290 ret = register_reboot_notifier(&advwdt_notifier);
292 printk (KERN_ERR PFX "cannot register reboot notifier (err=%d)\n",
297 ret = misc_register(&advwdt_miscdev);
299 printk (KERN_ERR PFX "cannot register miscdev on minor=%d (err=%d)\n",
300 WATCHDOG_MINOR, ret);
304 printk (KERN_INFO PFX "initialized. timeout=%d sec (nowayout=%d)\n",
310 unregister_reboot_notifier(&advwdt_notifier);
312 release_region(wdt_start, 1);
314 if (wdt_stop != wdt_start)
315 release_region(wdt_stop, 1);
322 misc_deregister(&advwdt_miscdev);
323 unregister_reboot_notifier(&advwdt_notifier);
324 if(wdt_stop != wdt_start)
325 release_region(wdt_stop,1);
326 release_region(wdt_start,1);
329 module_init(advwdt_init);
330 module_exit(advwdt_exit);
332 MODULE_LICENSE("GPL");
333 MODULE_AUTHOR("Marek Michalkiewicz <marekm@linux.org.pl>");
334 MODULE_DESCRIPTION("Advantech Single Board Computer WDT driver");
335 MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR);