2 * Wdt977 0.04: A Watchdog Device for Netwinder W83977AF chip
4 * (c) Copyright 1998 Rebel.com (Woody Suwalski <woody@netwinder.org>)
6 * -----------------------
8 * This program is free software; you can redistribute it and/or
9 * modify it under the terms of the GNU General Public License
10 * as published by the Free Software Foundation; either version
11 * 2 of the License, or (at your option) any later version.
13 * -----------------------
14 * 14-Dec-2001 Matt Domsch <Matt_Domsch@dell.com>
15 * Added nowayout module option to override CONFIG_WATCHDOG_NOWAYOUT
16 * 19-Dec-2001 Woody Suwalski: Netwinder fixes, ioctl interface
17 * 06-Jan-2002 Woody Suwalski: For compatibility, convert all timeouts
18 * from minutes to seconds.
19 * 07-Jul-2003 Daniele Bellucci: Audit return code of misc_register in
21 * 25-Oct-2005 Woody Suwalski: Convert addresses to #defs, add spinlocks
22 * remove limitiation to be used on
26 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
28 #include <linux/module.h>
29 #include <linux/moduleparam.h>
30 #include <linux/types.h>
31 #include <linux/kernel.h>
33 #include <linux/miscdevice.h>
34 #include <linux/init.h>
35 #include <linux/ioport.h>
36 #include <linux/watchdog.h>
37 #include <linux/notifier.h>
38 #include <linux/reboot.h>
40 #include <linux/uaccess.h>
42 #include <asm/system.h>
43 #include <asm/mach-types.h>
45 #define WATCHDOG_VERSION "0.04"
46 #define WATCHDOG_NAME "Wdt977"
48 #define IO_INDEX_PORT 0x370 /* on some systems it can be 0x3F0 */
49 #define IO_DATA_PORT (IO_INDEX_PORT + 1)
51 #define UNLOCK_DATA 0x87
52 #define LOCK_DATA 0xAA
53 #define DEVICE_REGISTER 0x07
56 #define DEFAULT_TIMEOUT 60 /* default timeout in seconds */
58 static int timeout = DEFAULT_TIMEOUT;
59 static int timeoutM; /* timeout in minutes */
60 static unsigned long timer_alive;
62 static char expect_close;
63 static DEFINE_SPINLOCK(spinlock);
65 module_param(timeout, int, 0);
66 MODULE_PARM_DESC(timeout, "Watchdog timeout in seconds (60..15300, default="
67 __MODULE_STRING(DEFAULT_TIMEOUT) ")");
68 module_param(testmode, int, 0);
69 MODULE_PARM_DESC(testmode, "Watchdog testmode (1 = no reboot), default=0");
71 static bool nowayout = WATCHDOG_NOWAYOUT;
72 module_param(nowayout, bool, 0);
73 MODULE_PARM_DESC(nowayout,
74 "Watchdog cannot be stopped once started (default="
75 __MODULE_STRING(WATCHDOG_NOWAYOUT) ")");
81 static int wdt977_start(void)
85 spin_lock_irqsave(&spinlock, flags);
87 /* unlock the SuperIO chip */
88 outb_p(UNLOCK_DATA, IO_INDEX_PORT);
89 outb_p(UNLOCK_DATA, IO_INDEX_PORT);
91 /* select device Aux2 (device=8) and set watchdog regs F2, F3 and F4
92 * F2 has the timeout in minutes
93 * F3 could be set to the POWER LED blink (with GP17 set to PowerLed)
94 * at timeout, and to reset timer on kbd/mouse activity (not impl.)
95 * F4 is used to just clear the TIMEOUT'ed state (bit 0)
97 outb_p(DEVICE_REGISTER, IO_INDEX_PORT);
98 outb_p(0x08, IO_DATA_PORT);
99 outb_p(0xF2, IO_INDEX_PORT);
100 outb_p(timeoutM, IO_DATA_PORT);
101 outb_p(0xF3, IO_INDEX_PORT);
102 outb_p(0x00, IO_DATA_PORT); /* another setting is 0E for
104 outb_p(0xF4, IO_INDEX_PORT);
105 outb_p(0x00, IO_DATA_PORT);
107 /* At last select device Aux1 (dev=7) and set GP16 as a
108 * watchdog output. In test mode watch the bit 1 on F4 to
109 * indicate "triggered"
112 outb_p(DEVICE_REGISTER, IO_INDEX_PORT);
113 outb_p(0x07, IO_DATA_PORT);
114 outb_p(0xE6, IO_INDEX_PORT);
115 outb_p(0x08, IO_DATA_PORT);
118 /* lock the SuperIO chip */
119 outb_p(LOCK_DATA, IO_INDEX_PORT);
121 spin_unlock_irqrestore(&spinlock, flags);
122 pr_info("activated\n");
131 static int wdt977_stop(void)
134 spin_lock_irqsave(&spinlock, flags);
136 /* unlock the SuperIO chip */
137 outb_p(UNLOCK_DATA, IO_INDEX_PORT);
138 outb_p(UNLOCK_DATA, IO_INDEX_PORT);
140 /* select device Aux2 (device=8) and set watchdog regs F2,F3 and F4
141 * F3 is reset to its default state
142 * F4 can clear the TIMEOUT'ed state (bit 0) - back to default
143 * We can not use GP17 as a PowerLed, as we use its usage as a RedLed
145 outb_p(DEVICE_REGISTER, IO_INDEX_PORT);
146 outb_p(0x08, IO_DATA_PORT);
147 outb_p(0xF2, IO_INDEX_PORT);
148 outb_p(0xFF, IO_DATA_PORT);
149 outb_p(0xF3, IO_INDEX_PORT);
150 outb_p(0x00, IO_DATA_PORT);
151 outb_p(0xF4, IO_INDEX_PORT);
152 outb_p(0x00, IO_DATA_PORT);
153 outb_p(0xF2, IO_INDEX_PORT);
154 outb_p(0x00, IO_DATA_PORT);
156 /* at last select device Aux1 (dev=7) and set
157 GP16 as a watchdog output */
158 outb_p(DEVICE_REGISTER, IO_INDEX_PORT);
159 outb_p(0x07, IO_DATA_PORT);
160 outb_p(0xE6, IO_INDEX_PORT);
161 outb_p(0x08, IO_DATA_PORT);
163 /* lock the SuperIO chip */
164 outb_p(LOCK_DATA, IO_INDEX_PORT);
166 spin_unlock_irqrestore(&spinlock, flags);
167 pr_info("shutdown\n");
173 * Send a keepalive ping to the watchdog
174 * This is done by simply re-writing the timeout to reg. 0xF2
177 static int wdt977_keepalive(void)
180 spin_lock_irqsave(&spinlock, flags);
182 /* unlock the SuperIO chip */
183 outb_p(UNLOCK_DATA, IO_INDEX_PORT);
184 outb_p(UNLOCK_DATA, IO_INDEX_PORT);
186 /* select device Aux2 (device=8) and kicks watchdog reg F2 */
187 /* F2 has the timeout in minutes */
188 outb_p(DEVICE_REGISTER, IO_INDEX_PORT);
189 outb_p(0x08, IO_DATA_PORT);
190 outb_p(0xF2, IO_INDEX_PORT);
191 outb_p(timeoutM, IO_DATA_PORT);
193 /* lock the SuperIO chip */
194 outb_p(LOCK_DATA, IO_INDEX_PORT);
195 spin_unlock_irqrestore(&spinlock, flags);
201 * Set the watchdog timeout value
204 static int wdt977_set_timeout(int t)
208 /* convert seconds to minutes, rounding up */
209 tmrval = (t + 59) / 60;
211 if (machine_is_netwinder()) {
212 /* we have a hw bug somewhere, so each 977 minute is actually
213 * only 30sec. This limits the max timeout to half of device
214 * max of 255 minutes...
219 if (tmrval < 1 || tmrval > 255)
222 /* timeout is the timeout in seconds, timeoutM is
223 the timeout in minutes) */
230 * Get the watchdog status
233 static int wdt977_get_status(int *status)
238 spin_lock_irqsave(&spinlock, flags);
240 /* unlock the SuperIO chip */
241 outb_p(UNLOCK_DATA, IO_INDEX_PORT);
242 outb_p(UNLOCK_DATA, IO_INDEX_PORT);
244 /* select device Aux2 (device=8) and read watchdog reg F4 */
245 outb_p(DEVICE_REGISTER, IO_INDEX_PORT);
246 outb_p(0x08, IO_DATA_PORT);
247 outb_p(0xF4, IO_INDEX_PORT);
248 new_status = inb_p(IO_DATA_PORT);
250 /* lock the SuperIO chip */
251 outb_p(LOCK_DATA, IO_INDEX_PORT);
253 spin_unlock_irqrestore(&spinlock, flags);
257 *status |= WDIOF_CARDRESET;
264 * /dev/watchdog handling
267 static int wdt977_open(struct inode *inode, struct file *file)
269 /* If the watchdog is alive we don't need to start it again */
270 if (test_and_set_bit(0, &timer_alive))
274 __module_get(THIS_MODULE);
277 return nonseekable_open(inode, file);
280 static int wdt977_release(struct inode *inode, struct file *file)
283 * Shut off the timer.
284 * Lock it in if it's a module and we set nowayout
286 if (expect_close == 42) {
288 clear_bit(0, &timer_alive);
291 pr_crit("Unexpected close, not stopping watchdog!\n");
300 * @file: file handle to the watchdog
301 * @buf: buffer to write (unused as data does not matter here
302 * @count: count of bytes
303 * @ppos: pointer to the position to write. No seeks allowed
305 * A write to a watchdog device is defined as a keepalive signal. Any
306 * write of data will do, as we we don't define content meaning.
309 static ssize_t wdt977_write(struct file *file, const char __user *buf,
310 size_t count, loff_t *ppos)
316 /* In case it was set long ago */
319 for (i = 0; i != count; i++) {
321 if (get_user(c, buf + i))
328 /* someone wrote to us, we should restart timer */
334 static const struct watchdog_info ident = {
335 .options = WDIOF_SETTIMEOUT |
338 .firmware_version = 1,
339 .identity = WATCHDOG_NAME,
344 * @inode: inode of the device
345 * @file: file handle to the device
346 * @cmd: watchdog command
347 * @arg: argument pointer
349 * The watchdog API defines a common set of functions for all watchdogs
350 * according to their available features.
353 static long wdt977_ioctl(struct file *file, unsigned int cmd,
357 int new_options, retval = -EINVAL;
360 struct watchdog_info __user *ident;
364 uarg.i = (int __user *)arg;
367 case WDIOC_GETSUPPORT:
368 return copy_to_user(uarg.ident, &ident,
369 sizeof(ident)) ? -EFAULT : 0;
371 case WDIOC_GETSTATUS:
372 wdt977_get_status(&status);
373 return put_user(status, uarg.i);
375 case WDIOC_GETBOOTSTATUS:
376 return put_user(0, uarg.i);
378 case WDIOC_SETOPTIONS:
379 if (get_user(new_options, uarg.i))
382 if (new_options & WDIOS_DISABLECARD) {
387 if (new_options & WDIOS_ENABLECARD) {
394 case WDIOC_KEEPALIVE:
398 case WDIOC_SETTIMEOUT:
399 if (get_user(new_timeout, uarg.i))
402 if (wdt977_set_timeout(new_timeout))
408 case WDIOC_GETTIMEOUT:
409 return put_user(timeout, uarg.i);
417 static int wdt977_notify_sys(struct notifier_block *this, unsigned long code,
420 if (code == SYS_DOWN || code == SYS_HALT)
425 static const struct file_operations wdt977_fops = {
426 .owner = THIS_MODULE,
428 .write = wdt977_write,
429 .unlocked_ioctl = wdt977_ioctl,
431 .release = wdt977_release,
434 static struct miscdevice wdt977_miscdev = {
435 .minor = WATCHDOG_MINOR,
437 .fops = &wdt977_fops,
440 static struct notifier_block wdt977_notifier = {
441 .notifier_call = wdt977_notify_sys,
444 static int __init wd977_init(void)
448 pr_info("driver v%s\n", WATCHDOG_VERSION);
450 /* Check that the timeout value is within its range;
451 if not reset to the default */
452 if (wdt977_set_timeout(timeout)) {
453 wdt977_set_timeout(DEFAULT_TIMEOUT);
454 pr_info("timeout value must be 60 < timeout < 15300, using %d\n",
458 /* on Netwinder the IOports are already reserved by
459 * arch/arm/mach-footbridge/netwinder-hw.c
461 if (!machine_is_netwinder()) {
462 if (!request_region(IO_INDEX_PORT, 2, WATCHDOG_NAME)) {
463 pr_err("I/O address 0x%04x already in use\n",
470 rc = register_reboot_notifier(&wdt977_notifier);
472 pr_err("cannot register reboot notifier (err=%d)\n", rc);
476 rc = misc_register(&wdt977_miscdev);
478 pr_err("cannot register miscdev on minor=%d (err=%d)\n",
479 wdt977_miscdev.minor, rc);
483 pr_info("initialized. timeout=%d sec (nowayout=%d, testmode=%i)\n",
484 timeout, nowayout, testmode);
489 unregister_reboot_notifier(&wdt977_notifier);
491 if (!machine_is_netwinder())
492 release_region(IO_INDEX_PORT, 2);
497 static void __exit wd977_exit(void)
500 misc_deregister(&wdt977_miscdev);
501 unregister_reboot_notifier(&wdt977_notifier);
502 release_region(IO_INDEX_PORT, 2);
505 module_init(wd977_init);
506 module_exit(wd977_exit);
508 MODULE_AUTHOR("Woody Suwalski <woodys@xandros.com>");
509 MODULE_DESCRIPTION("W83977AF Watchdog driver");
510 MODULE_LICENSE("GPL");
511 MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR);