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/platform_device.h>
41 #include <linux/init.h>
44 #include <asm/uaccess.h>
45 #include <asm/system.h>
47 #define DRV_NAME "advantechwdt"
48 #define PFX DRV_NAME ": "
49 #define WATCHDOG_NAME "Advantech WDT"
50 #define WATCHDOG_TIMEOUT 60 /* 60 sec default timeout */
52 static struct platform_device *advwdt_platform_device; /* the watchdog platform device */
53 static unsigned long advwdt_is_open;
54 static char adv_expect_close;
57 * You must set these - there is no sane way to probe for this board.
59 * To enable or restart, write the timeout value in seconds (1 to 63)
60 * to I/O port wdt_start. To disable, read I/O port wdt_stop.
61 * Both are 0x443 for most boards (tested on a PCA-6276VE-00B1), but
62 * check your manual (at least the PCA-6159 seems to be different -
63 * the manual says wdt_stop is 0x43, not 0x443).
64 * (0x43 is also a write-only control register for the 8254 timer!)
67 static int wdt_stop = 0x443;
68 module_param(wdt_stop, int, 0);
69 MODULE_PARM_DESC(wdt_stop, "Advantech WDT 'stop' io port (default 0x443)");
71 static int wdt_start = 0x443;
72 module_param(wdt_start, int, 0);
73 MODULE_PARM_DESC(wdt_start, "Advantech WDT 'start' io port (default 0x443)");
75 static int timeout = WATCHDOG_TIMEOUT; /* in seconds */
76 module_param(timeout, int, 0);
77 MODULE_PARM_DESC(timeout, "Watchdog timeout in seconds. 1<= timeout <=63, default=" __MODULE_STRING(WATCHDOG_TIMEOUT) ".");
79 static int nowayout = WATCHDOG_NOWAYOUT;
80 module_param(nowayout, int, 0);
81 MODULE_PARM_DESC(nowayout, "Watchdog cannot be stopped once started (default=" __MODULE_STRING(WATCHDOG_NOWAYOUT) ")");
90 /* Write a watchdog value */
91 outb_p(timeout, wdt_start);
101 advwdt_set_heartbeat(int t)
103 if ((t < 1) || (t > 63))
111 * /dev/watchdog handling
115 advwdt_write(struct file *file, const char __user *buf, size_t count, loff_t *ppos)
121 adv_expect_close = 0;
123 for (i = 0; i != count; i++) {
125 if (get_user(c, buf+i))
128 adv_expect_close = 42;
137 advwdt_ioctl(struct inode *inode, struct file *file, unsigned int cmd,
141 void __user *argp = (void __user *)arg;
142 int __user *p = argp;
143 static struct watchdog_info ident = {
144 .options = WDIOF_KEEPALIVEPING | WDIOF_SETTIMEOUT | WDIOF_MAGICCLOSE,
145 .firmware_version = 1,
146 .identity = WATCHDOG_NAME,
150 case WDIOC_GETSUPPORT:
151 if (copy_to_user(argp, &ident, sizeof(ident)))
155 case WDIOC_GETSTATUS:
156 case WDIOC_GETBOOTSTATUS:
157 return put_user(0, p);
159 case WDIOC_KEEPALIVE:
163 case WDIOC_SETTIMEOUT:
164 if (get_user(new_timeout, p))
166 if (advwdt_set_heartbeat(new_timeout))
171 case WDIOC_GETTIMEOUT:
172 return put_user(timeout, p);
174 case WDIOC_SETOPTIONS:
176 int options, retval = -EINVAL;
178 if (get_user(options, p))
181 if (options & WDIOS_DISABLECARD) {
186 if (options & WDIOS_ENABLECARD) {
201 advwdt_open(struct inode *inode, struct file *file)
203 if (test_and_set_bit(0, &advwdt_is_open))
210 return nonseekable_open(inode, file);
214 advwdt_close(struct inode *inode, struct file *file)
216 if (adv_expect_close == 42) {
219 printk(KERN_CRIT PFX "Unexpected close, not stopping watchdog!\n");
222 clear_bit(0, &advwdt_is_open);
223 adv_expect_close = 0;
228 * Notifier for system down
232 advwdt_notify_sys(struct notifier_block *this, unsigned long code,
235 if (code == SYS_DOWN || code == SYS_HALT) {
236 /* Turn the WDT off */
246 static const struct file_operations advwdt_fops = {
247 .owner = THIS_MODULE,
249 .write = advwdt_write,
250 .ioctl = advwdt_ioctl,
252 .release = advwdt_close,
255 static struct miscdevice advwdt_miscdev = {
256 .minor = WATCHDOG_MINOR,
258 .fops = &advwdt_fops,
262 * The WDT needs to learn about soft shutdowns in order to
263 * turn the timebomb registers off.
266 static struct notifier_block advwdt_notifier = {
267 .notifier_call = advwdt_notify_sys,
271 * Init & exit routines
275 advwdt_probe(struct platform_device *dev)
279 if (wdt_stop != wdt_start) {
280 if (!request_region(wdt_stop, 1, WATCHDOG_NAME)) {
281 printk (KERN_ERR PFX "I/O address 0x%04x already in use\n",
288 if (!request_region(wdt_start, 1, WATCHDOG_NAME)) {
289 printk (KERN_ERR PFX "I/O address 0x%04x already in use\n",
295 /* Check that the heartbeat value is within it's range ; if not reset to the default */
296 if (advwdt_set_heartbeat(timeout)) {
297 advwdt_set_heartbeat(WATCHDOG_TIMEOUT);
298 printk (KERN_INFO PFX "timeout value must be 1<=x<=63, using %d\n",
302 ret = register_reboot_notifier(&advwdt_notifier);
304 printk (KERN_ERR PFX "cannot register reboot notifier (err=%d)\n",
309 ret = misc_register(&advwdt_miscdev);
311 printk (KERN_ERR PFX "cannot register miscdev on minor=%d (err=%d)\n",
312 WATCHDOG_MINOR, ret);
316 printk (KERN_INFO PFX "initialized. timeout=%d sec (nowayout=%d)\n",
322 unregister_reboot_notifier(&advwdt_notifier);
324 release_region(wdt_start, 1);
326 if (wdt_stop != wdt_start)
327 release_region(wdt_stop, 1);
332 advwdt_remove(struct platform_device *dev)
334 misc_deregister(&advwdt_miscdev);
335 unregister_reboot_notifier(&advwdt_notifier);
336 release_region(wdt_start,1);
337 if(wdt_stop != wdt_start)
338 release_region(wdt_stop,1);
343 static struct platform_driver advwdt_driver = {
344 .probe = advwdt_probe,
345 .remove = __devexit_p(advwdt_remove),
347 .owner = THIS_MODULE,
357 printk(KERN_INFO "WDT driver for Advantech single board computer initialising.\n");
359 err = platform_driver_register(&advwdt_driver);
363 advwdt_platform_device = platform_device_register_simple(DRV_NAME, -1, NULL, 0);
364 if (IS_ERR(advwdt_platform_device)) {
365 err = PTR_ERR(advwdt_platform_device);
366 goto unreg_platform_driver;
371 unreg_platform_driver:
372 platform_driver_unregister(&advwdt_driver);
379 platform_device_unregister(advwdt_platform_device);
380 platform_driver_unregister(&advwdt_driver);
381 printk(KERN_INFO PFX "Watchdog Module Unloaded.\n");
384 module_init(advwdt_init);
385 module_exit(advwdt_exit);
387 MODULE_LICENSE("GPL");
388 MODULE_AUTHOR("Marek Michalkiewicz <marekm@linux.org.pl>");
389 MODULE_DESCRIPTION("Advantech Single Board Computer WDT driver");
390 MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR);