2 * w83697ug/uf WDT driver
4 * (c) Copyright 2008 Flemming Fransen <ff@nrvissing.net>
5 * reused original code to support w83697ug/uf.
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 2007 Vlad Drukker <vlad@storewiz.com>
12 * added support for W83627THF.
14 * (c) Copyright 2003 Pádraig Brady <P@draigBrady.com>
16 * (c) Copyright 2000-2001 Marek Michalkiewicz <marekm@linux.org.pl>
18 * (c) Copyright 1996 Alan Cox <alan@redhat.com>, All Rights Reserved.
19 * http://www.redhat.com
21 * This program is free software; you can redistribute it and/or
22 * modify it under the terms of the GNU General Public License
23 * as published by the Free Software Foundation; either version
24 * 2 of the License, or (at your option) any later version.
26 * Neither Alan Cox nor CymruNet Ltd. admit liability nor provide
27 * warranty for any of this software. This material is provided
28 * "AS-IS" and at no charge.
30 * (c) Copyright 1995 Alan Cox <alan@redhat.com>
33 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
35 #include <linux/module.h>
36 #include <linux/moduleparam.h>
37 #include <linux/types.h>
38 #include <linux/miscdevice.h>
39 #include <linux/watchdog.h>
41 #include <linux/ioport.h>
42 #include <linux/notifier.h>
43 #include <linux/reboot.h>
44 #include <linux/init.h>
45 #include <linux/spinlock.h>
47 #include <linux/uaccess.h>
49 #include <asm/system.h>
51 #define WATCHDOG_NAME "w83697ug/uf WDT"
52 #define WATCHDOG_TIMEOUT 60 /* 60 sec default timeout */
54 static unsigned long wdt_is_open;
55 static char expect_close;
56 static DEFINE_SPINLOCK(io_lock);
58 static int wdt_io = 0x2e;
59 module_param(wdt_io, int, 0);
60 MODULE_PARM_DESC(wdt_io, "w83697ug/uf WDT io port (default 0x2e)");
62 static int timeout = WATCHDOG_TIMEOUT; /* in seconds */
63 module_param(timeout, int, 0);
64 MODULE_PARM_DESC(timeout,
65 "Watchdog timeout in seconds. 1<= timeout <=255 (default="
66 __MODULE_STRING(WATCHDOG_TIMEOUT) ")");
68 static bool nowayout = WATCHDOG_NOWAYOUT;
69 module_param(nowayout, bool, 0);
70 MODULE_PARM_DESC(nowayout,
71 "Watchdog cannot be stopped once started (default="
72 __MODULE_STRING(WATCHDOG_NOWAYOUT) ")");
78 #define WDT_EFER (wdt_io+0) /* Extended Function Enable Registers */
79 #define WDT_EFIR (wdt_io+0) /* Extended Function Index Register
81 #define WDT_EFDR (WDT_EFIR+1) /* Extended Function Data Register */
83 static int w83697ug_select_wd_register(void)
86 unsigned char version;
88 outb_p(0x87, WDT_EFER); /* Enter extended function mode */
89 outb_p(0x87, WDT_EFER); /* Again according to manual */
91 outb(0x20, WDT_EFER); /* check chip version */
92 version = inb(WDT_EFDR);
94 if (version == 0x68) { /* W83697UG */
95 pr_info("Watchdog chip version 0x%02x = W83697UG/UF found at 0x%04x\n",
98 outb_p(0x2b, WDT_EFER);
99 c = inb_p(WDT_EFDR); /* select WDT0 */
101 outb_p(0x2b, WDT_EFER);
102 outb_p(c, WDT_EFDR); /* set pin118 to WDT0 */
105 pr_err("No W83697UG/UF could be found\n");
109 outb_p(0x07, WDT_EFER); /* point to logical device number reg */
110 outb_p(0x08, WDT_EFDR); /* select logical device 8 (GPIO2) */
111 outb_p(0x30, WDT_EFER); /* select CR30 */
113 outb_p(c | 0x01, WDT_EFDR); /* set bit 0 to activate GPIO2 */
118 static void w83697ug_unselect_wd_register(void)
120 outb_p(0xAA, WDT_EFER); /* Leave extended function mode */
123 static int w83697ug_init(void)
128 ret = w83697ug_select_wd_register();
132 outb_p(0xF6, WDT_EFER); /* Select CRF6 */
133 t = inb_p(WDT_EFDR); /* read CRF6 */
135 pr_info("Watchdog already running. Resetting timeout to %d sec\n",
137 outb_p(timeout, WDT_EFDR); /* Write back to CRF6 */
139 outb_p(0xF5, WDT_EFER); /* Select CRF5 */
140 t = inb_p(WDT_EFDR); /* read CRF5 */
141 t &= ~0x0C; /* set second mode &
142 disable keyboard turning off watchdog */
143 outb_p(t, WDT_EFDR); /* Write back to CRF5 */
145 w83697ug_unselect_wd_register();
149 static void wdt_ctrl(int timeout)
153 if (w83697ug_select_wd_register() < 0) {
154 spin_unlock(&io_lock);
158 outb_p(0xF4, WDT_EFER); /* Select CRF4 */
159 outb_p(timeout, WDT_EFDR); /* Write Timeout counter to CRF4 */
161 w83697ug_unselect_wd_register();
163 spin_unlock(&io_lock);
166 static int wdt_ping(void)
172 static int wdt_disable(void)
178 static int wdt_set_heartbeat(int t)
180 if (t < 1 || t > 255)
187 static ssize_t wdt_write(struct file *file, const char __user *buf,
188 size_t count, loff_t *ppos)
196 for (i = 0; i != count; i++) {
198 if (get_user(c, buf + i))
209 static long wdt_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
211 void __user *argp = (void __user *)arg;
212 int __user *p = argp;
214 static const struct watchdog_info ident = {
215 .options = WDIOF_KEEPALIVEPING |
218 .firmware_version = 1,
219 .identity = "W83697UG WDT",
223 case WDIOC_GETSUPPORT:
224 if (copy_to_user(argp, &ident, sizeof(ident)))
228 case WDIOC_GETSTATUS:
229 case WDIOC_GETBOOTSTATUS:
230 return put_user(0, p);
232 case WDIOC_SETOPTIONS:
234 int options, retval = -EINVAL;
236 if (get_user(options, p))
239 if (options & WDIOS_DISABLECARD) {
244 if (options & WDIOS_ENABLECARD) {
252 case WDIOC_KEEPALIVE:
256 case WDIOC_SETTIMEOUT:
257 if (get_user(new_timeout, p))
259 if (wdt_set_heartbeat(new_timeout))
264 case WDIOC_GETTIMEOUT:
265 return put_user(timeout, p);
273 static int wdt_open(struct inode *inode, struct file *file)
275 if (test_and_set_bit(0, &wdt_is_open))
282 return nonseekable_open(inode, file);
285 static int wdt_close(struct inode *inode, struct file *file)
287 if (expect_close == 42)
290 pr_crit("Unexpected close, not stopping watchdog!\n");
294 clear_bit(0, &wdt_is_open);
299 * Notifier for system down
302 static int wdt_notify_sys(struct notifier_block *this, unsigned long code,
305 if (code == SYS_DOWN || code == SYS_HALT)
306 wdt_disable(); /* Turn the WDT off */
315 static const struct file_operations wdt_fops = {
316 .owner = THIS_MODULE,
319 .unlocked_ioctl = wdt_ioctl,
321 .release = wdt_close,
324 static struct miscdevice wdt_miscdev = {
325 .minor = WATCHDOG_MINOR,
331 * The WDT needs to learn about soft shutdowns in order to
332 * turn the timebomb registers off.
335 static struct notifier_block wdt_notifier = {
336 .notifier_call = wdt_notify_sys,
339 static int __init wdt_init(void)
343 pr_info("WDT driver for the Winbond(TM) W83697UG/UF Super I/O chip initialising\n");
345 if (wdt_set_heartbeat(timeout)) {
346 wdt_set_heartbeat(WATCHDOG_TIMEOUT);
347 pr_info("timeout value must be 1<=timeout<=255, using %d\n",
351 if (!request_region(wdt_io, 1, WATCHDOG_NAME)) {
352 pr_err("I/O address 0x%04x already in use\n", wdt_io);
357 ret = w83697ug_init();
361 ret = register_reboot_notifier(&wdt_notifier);
363 pr_err("cannot register reboot notifier (err=%d)\n", ret);
367 ret = misc_register(&wdt_miscdev);
369 pr_err("cannot register miscdev on minor=%d (err=%d)\n",
370 WATCHDOG_MINOR, ret);
374 pr_info("initialized. timeout=%d sec (nowayout=%d)\n",
380 unregister_reboot_notifier(&wdt_notifier);
382 release_region(wdt_io, 1);
386 static void __exit wdt_exit(void)
388 misc_deregister(&wdt_miscdev);
389 unregister_reboot_notifier(&wdt_notifier);
390 release_region(wdt_io, 1);
393 module_init(wdt_init);
394 module_exit(wdt_exit);
396 MODULE_LICENSE("GPL");
397 MODULE_AUTHOR("Flemming Frandsen <ff@nrvissing.net>");
398 MODULE_DESCRIPTION("w83697ug/uf WDT driver");
399 MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR);