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 #include <linux/module.h>
34 #include <linux/moduleparam.h>
35 #include <linux/types.h>
36 #include <linux/miscdevice.h>
37 #include <linux/watchdog.h>
39 #include <linux/ioport.h>
40 #include <linux/notifier.h>
41 #include <linux/reboot.h>
42 #include <linux/init.h>
43 #include <linux/spinlock.h>
45 #include <linux/uaccess.h>
47 #include <asm/system.h>
49 #define WATCHDOG_NAME "w83697ug/uf WDT"
50 #define PFX WATCHDOG_NAME ": "
51 #define WATCHDOG_TIMEOUT 60 /* 60 sec default timeout */
53 static unsigned long wdt_is_open;
54 static char expect_close;
55 static DEFINE_SPINLOCK(io_lock);
57 static int wdt_io = 0x2e;
58 module_param(wdt_io, int, 0);
59 MODULE_PARM_DESC(wdt_io, "w83697ug/uf WDT io port (default 0x2e)");
61 static int timeout = WATCHDOG_TIMEOUT; /* in seconds */
62 module_param(timeout, int, 0);
63 MODULE_PARM_DESC(timeout,
64 "Watchdog timeout in seconds. 1<= timeout <=255 (default="
65 __MODULE_STRING(WATCHDOG_TIMEOUT) ")");
67 static int nowayout = WATCHDOG_NOWAYOUT;
68 module_param(nowayout, int, 0);
69 MODULE_PARM_DESC(nowayout,
70 "Watchdog cannot be stopped once started (default="
71 __MODULE_STRING(WATCHDOG_NOWAYOUT) ")");
77 #define WDT_EFER (wdt_io+0) /* Extended Function Enable Registers */
78 #define WDT_EFIR (wdt_io+0) /* Extended Function Index Register
80 #define WDT_EFDR (WDT_EFIR+1) /* Extended Function Data Register */
82 static int w83697ug_select_wd_register(void)
85 unsigned char version;
87 outb_p(0x87, WDT_EFER); /* Enter extended function mode */
88 outb_p(0x87, WDT_EFER); /* Again according to manual */
90 outb(0x20, WDT_EFER); /* check chip version */
91 version = inb(WDT_EFDR);
93 if (version == 0x68) { /* W83697UG */
94 printk(KERN_INFO PFX "Watchdog chip version 0x%02x = "
95 "W83697UG/UF found at 0x%04x\n", version, wdt_io);
97 outb_p(0x2b, WDT_EFER);
98 c = inb_p(WDT_EFDR); /* select WDT0 */
100 outb_p(0x2b, WDT_EFER);
101 outb_p(c, WDT_EFDR); /* set pin118 to WDT0 */
104 printk(KERN_ERR PFX "No W83697UG/UF could be found\n");
108 outb_p(0x07, WDT_EFER); /* point to logical device number reg */
109 outb_p(0x08, WDT_EFDR); /* select logical device 8 (GPIO2) */
110 outb_p(0x30, WDT_EFER); /* select CR30 */
112 outb_p(c || 0x01, WDT_EFDR); /* set bit 0 to activate GPIO2 */
117 static void w83697ug_unselect_wd_register(void)
119 outb_p(0xAA, WDT_EFER); /* Leave extended function mode */
122 static int w83697ug_init(void)
127 ret = w83697ug_select_wd_register();
131 outb_p(0xF6, WDT_EFER); /* Select CRF6 */
132 t = inb_p(WDT_EFDR); /* read CRF6 */
134 printk(KERN_INFO PFX "Watchdog already running."
135 " Resetting timeout to %d sec\n", timeout);
136 outb_p(timeout, WDT_EFDR); /* Write back to CRF6 */
138 outb_p(0xF5, WDT_EFER); /* Select CRF5 */
139 t = inb_p(WDT_EFDR); /* read CRF5 */
140 t &= ~0x0C; /* set second mode &
141 disable keyboard turning off watchdog */
142 outb_p(t, WDT_EFDR); /* Write back to CRF5 */
144 w83697ug_unselect_wd_register();
148 static void wdt_ctrl(int timeout)
152 if (w83697ug_select_wd_register() < 0)
155 outb_p(0xF4, WDT_EFER); /* Select CRF4 */
156 outb_p(timeout, WDT_EFDR); /* Write Timeout counter to CRF4 */
158 w83697ug_unselect_wd_register();
160 spin_unlock(&io_lock);
163 static int wdt_ping(void)
169 static int wdt_disable(void)
175 static int wdt_set_heartbeat(int t)
177 if (t < 1 || t > 255)
184 static ssize_t wdt_write(struct file *file, const char __user *buf,
185 size_t count, loff_t *ppos)
193 for (i = 0; i != count; i++) {
195 if (get_user(c, buf + i))
206 static long wdt_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
208 void __user *argp = (void __user *)arg;
209 int __user *p = argp;
211 static const struct watchdog_info ident = {
212 .options = WDIOF_KEEPALIVEPING |
215 .firmware_version = 1,
216 .identity = "W83697UG WDT",
220 case WDIOC_GETSUPPORT:
221 if (copy_to_user(argp, &ident, sizeof(ident)))
225 case WDIOC_GETSTATUS:
226 case WDIOC_GETBOOTSTATUS:
227 return put_user(0, p);
229 case WDIOC_SETOPTIONS:
231 int options, retval = -EINVAL;
233 if (get_user(options, p))
236 if (options & WDIOS_DISABLECARD) {
241 if (options & WDIOS_ENABLECARD) {
249 case WDIOC_KEEPALIVE:
253 case WDIOC_SETTIMEOUT:
254 if (get_user(new_timeout, p))
256 if (wdt_set_heartbeat(new_timeout))
261 case WDIOC_GETTIMEOUT:
262 return put_user(timeout, p);
270 static int wdt_open(struct inode *inode, struct file *file)
272 if (test_and_set_bit(0, &wdt_is_open))
279 return nonseekable_open(inode, file);
282 static int wdt_close(struct inode *inode, struct file *file)
284 if (expect_close == 42)
288 "Unexpected close, not stopping watchdog!\n");
292 clear_bit(0, &wdt_is_open);
297 * Notifier for system down
300 static int wdt_notify_sys(struct notifier_block *this, unsigned long code,
303 if (code == SYS_DOWN || code == SYS_HALT)
304 wdt_disable(); /* Turn the WDT off */
313 static const struct file_operations wdt_fops = {
314 .owner = THIS_MODULE,
317 .unlocked_ioctl = wdt_ioctl,
319 .release = wdt_close,
322 static struct miscdevice wdt_miscdev = {
323 .minor = WATCHDOG_MINOR,
329 * The WDT needs to learn about soft shutdowns in order to
330 * turn the timebomb registers off.
333 static struct notifier_block wdt_notifier = {
334 .notifier_call = wdt_notify_sys,
337 static int __init wdt_init(void)
341 printk(KERN_INFO "WDT driver for the Winbond(TM) W83697UG/UF Super I/O chip initialising.\n");
343 if (wdt_set_heartbeat(timeout)) {
344 wdt_set_heartbeat(WATCHDOG_TIMEOUT);
346 "timeout value must be 1<=timeout<=255, using %d\n",
350 if (!request_region(wdt_io, 1, WATCHDOG_NAME)) {
351 printk(KERN_ERR PFX "I/O address 0x%04x already in use\n",
357 ret = w83697ug_init();
361 ret = register_reboot_notifier(&wdt_notifier);
364 "cannot register reboot notifier (err=%d)\n", ret);
368 ret = misc_register(&wdt_miscdev);
371 "cannot register miscdev on minor=%d (err=%d)\n",
372 WATCHDOG_MINOR, ret);
376 printk(KERN_INFO PFX "initialized. timeout=%d sec (nowayout=%d)\n",
382 unregister_reboot_notifier(&wdt_notifier);
384 release_region(wdt_io, 1);
388 static void __exit wdt_exit(void)
390 misc_deregister(&wdt_miscdev);
391 unregister_reboot_notifier(&wdt_notifier);
392 release_region(wdt_io, 1);
395 module_init(wdt_init);
396 module_exit(wdt_exit);
398 MODULE_LICENSE("GPL");
399 MODULE_AUTHOR("Flemming Frandsen <ff@nrvissing.net>");
400 MODULE_DESCRIPTION("w83697ug/uf WDT driver");
401 MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR);