Linux 2.6.20.7
[linux/fpc-iii.git] / drivers / char / watchdog / w83627hf_wdt.c
blob07d4bff27226b378a6d88d3c1fb0abe9f9f8172a
1 /*
2 * w83627hf WDT driver
4 * (c) Copyright 2003 Pádraig Brady <P@draigBrady.com>
6 * Based on advantechwdt.c which is based on wdt.c.
7 * Original copyright messages:
9 * (c) Copyright 2000-2001 Marek Michalkiewicz <marekm@linux.org.pl>
11 * (c) Copyright 1996 Alan Cox <alan@redhat.com>, All Rights Reserved.
12 * http://www.redhat.com
14 * This program is free software; you can redistribute it and/or
15 * modify it under the terms of the GNU General Public License
16 * as published by the Free Software Foundation; either version
17 * 2 of the License, or (at your option) any later version.
19 * Neither Alan Cox nor CymruNet Ltd. admit liability nor provide
20 * warranty for any of this software. This material is provided
21 * "AS-IS" and at no charge.
23 * (c) Copyright 1995 Alan Cox <alan@redhat.com>
26 #include <linux/module.h>
27 #include <linux/moduleparam.h>
28 #include <linux/types.h>
29 #include <linux/miscdevice.h>
30 #include <linux/watchdog.h>
31 #include <linux/fs.h>
32 #include <linux/ioport.h>
33 #include <linux/notifier.h>
34 #include <linux/reboot.h>
35 #include <linux/init.h>
36 #include <linux/spinlock.h>
38 #include <asm/io.h>
39 #include <asm/uaccess.h>
40 #include <asm/system.h>
42 #define WATCHDOG_NAME "w83627hf WDT"
43 #define PFX WATCHDOG_NAME ": "
44 #define WATCHDOG_TIMEOUT 60 /* 60 sec default timeout */
46 static unsigned long wdt_is_open;
47 static char expect_close;
48 static spinlock_t io_lock;
50 /* You must set this - there is no sane way to probe for this board. */
51 static int wdt_io = 0x2E;
52 module_param(wdt_io, int, 0);
53 MODULE_PARM_DESC(wdt_io, "w83627hf WDT io port (default 0x2E)");
55 static int timeout = WATCHDOG_TIMEOUT; /* in seconds */
56 module_param(timeout, int, 0);
57 MODULE_PARM_DESC(timeout, "Watchdog timeout in seconds. 1<= timeout <=63, default=" __MODULE_STRING(WATCHDOG_TIMEOUT) ".");
59 static int nowayout = WATCHDOG_NOWAYOUT;
60 module_param(nowayout, int, 0);
61 MODULE_PARM_DESC(nowayout, "Watchdog cannot be stopped once started (default=CONFIG_WATCHDOG_NOWAYOUT)");
64 * Kernel methods.
67 #define WDT_EFER (wdt_io+0) /* Extended Function Enable Registers */
68 #define WDT_EFIR (wdt_io+0) /* Extended Function Index Register (same as EFER) */
69 #define WDT_EFDR (WDT_EFIR+1) /* Extended Function Data Register */
71 static void
72 w83627hf_select_wd_register(void)
74 outb_p(0x87, WDT_EFER); /* Enter extended function mode */
75 outb_p(0x87, WDT_EFER); /* Again according to manual */
77 outb_p(0x07, WDT_EFER); /* point to logical device number reg */
78 outb_p(0x08, WDT_EFDR); /* select logical device 8 (GPIO2) */
79 outb_p(0x30, WDT_EFER); /* select CR30 */
80 outb_p(0x01, WDT_EFDR); /* set bit 0 to activate GPIO2 */
83 static void
84 w83627hf_unselect_wd_register(void)
86 outb_p(0xAA, WDT_EFER); /* Leave extended function mode */
89 /* tyan motherboards seem to set F5 to 0x4C ?
90 * So explicitly init to appropriate value. */
91 static void
92 w83627hf_init(void)
94 unsigned char t;
96 w83627hf_select_wd_register();
98 outb_p(0xF6, WDT_EFER); /* Select CRF6 */
99 t=inb_p(WDT_EFDR); /* read CRF6 */
100 if (t != 0) {
101 printk (KERN_INFO PFX "Watchdog already running. Resetting timeout to %d sec\n", timeout);
102 outb_p(timeout, WDT_EFDR); /* Write back to CRF6 */
104 outb_p(0xF5, WDT_EFER); /* Select CRF5 */
105 t=inb_p(WDT_EFDR); /* read CRF5 */
106 t&=~0x0C; /* set second mode & disable keyboard turning off watchdog */
107 outb_p(t, WDT_EFDR); /* Write back to CRF5 */
109 w83627hf_unselect_wd_register();
112 static void
113 wdt_ctrl(int timeout)
115 spin_lock(&io_lock);
117 w83627hf_select_wd_register();
119 outb_p(0xF6, WDT_EFER); /* Select CRF6 */
120 outb_p(timeout, WDT_EFDR); /* Write Timeout counter to CRF6 */
122 w83627hf_unselect_wd_register();
124 spin_unlock(&io_lock);
127 static int
128 wdt_ping(void)
130 wdt_ctrl(timeout);
131 return 0;
134 static int
135 wdt_disable(void)
137 wdt_ctrl(0);
138 return 0;
141 static int
142 wdt_set_heartbeat(int t)
144 if ((t < 1) || (t > 63))
145 return -EINVAL;
147 timeout = t;
148 return 0;
151 static ssize_t
152 wdt_write(struct file *file, const char __user *buf, size_t count, loff_t *ppos)
154 if (count) {
155 if (!nowayout) {
156 size_t i;
158 expect_close = 0;
160 for (i = 0; i != count; i++) {
161 char c;
162 if (get_user(c, buf+i))
163 return -EFAULT;
164 if (c == 'V')
165 expect_close = 42;
168 wdt_ping();
170 return count;
173 static int
174 wdt_ioctl(struct inode *inode, struct file *file, unsigned int cmd,
175 unsigned long arg)
177 void __user *argp = (void __user *)arg;
178 int __user *p = argp;
179 int new_timeout;
180 static struct watchdog_info ident = {
181 .options = WDIOF_KEEPALIVEPING | WDIOF_SETTIMEOUT | WDIOF_MAGICCLOSE,
182 .firmware_version = 1,
183 .identity = "W83627HF WDT",
186 switch (cmd) {
187 case WDIOC_GETSUPPORT:
188 if (copy_to_user(argp, &ident, sizeof(ident)))
189 return -EFAULT;
190 break;
192 case WDIOC_GETSTATUS:
193 case WDIOC_GETBOOTSTATUS:
194 return put_user(0, p);
196 case WDIOC_KEEPALIVE:
197 wdt_ping();
198 break;
200 case WDIOC_SETTIMEOUT:
201 if (get_user(new_timeout, p))
202 return -EFAULT;
203 if (wdt_set_heartbeat(new_timeout))
204 return -EINVAL;
205 wdt_ping();
206 /* Fall */
208 case WDIOC_GETTIMEOUT:
209 return put_user(timeout, p);
211 case WDIOC_SETOPTIONS:
213 int options, retval = -EINVAL;
215 if (get_user(options, p))
216 return -EFAULT;
218 if (options & WDIOS_DISABLECARD) {
219 wdt_disable();
220 retval = 0;
223 if (options & WDIOS_ENABLECARD) {
224 wdt_ping();
225 retval = 0;
228 return retval;
231 default:
232 return -ENOTTY;
234 return 0;
237 static int
238 wdt_open(struct inode *inode, struct file *file)
240 if (test_and_set_bit(0, &wdt_is_open))
241 return -EBUSY;
243 * Activate
246 wdt_ping();
247 return nonseekable_open(inode, file);
250 static int
251 wdt_close(struct inode *inode, struct file *file)
253 if (expect_close == 42) {
254 wdt_disable();
255 } else {
256 printk(KERN_CRIT PFX "Unexpected close, not stopping watchdog!\n");
257 wdt_ping();
259 expect_close = 0;
260 clear_bit(0, &wdt_is_open);
261 return 0;
265 * Notifier for system down
268 static int
269 wdt_notify_sys(struct notifier_block *this, unsigned long code,
270 void *unused)
272 if (code == SYS_DOWN || code == SYS_HALT) {
273 /* Turn the WDT off */
274 wdt_disable();
276 return NOTIFY_DONE;
280 * Kernel Interfaces
283 static const struct file_operations wdt_fops = {
284 .owner = THIS_MODULE,
285 .llseek = no_llseek,
286 .write = wdt_write,
287 .ioctl = wdt_ioctl,
288 .open = wdt_open,
289 .release = wdt_close,
292 static struct miscdevice wdt_miscdev = {
293 .minor = WATCHDOG_MINOR,
294 .name = "watchdog",
295 .fops = &wdt_fops,
299 * The WDT needs to learn about soft shutdowns in order to
300 * turn the timebomb registers off.
303 static struct notifier_block wdt_notifier = {
304 .notifier_call = wdt_notify_sys,
307 static int __init
308 wdt_init(void)
310 int ret;
312 spin_lock_init(&io_lock);
314 printk(KERN_INFO "WDT driver for the Winbond(TM) W83627HF Super I/O chip initialising.\n");
316 if (wdt_set_heartbeat(timeout)) {
317 wdt_set_heartbeat(WATCHDOG_TIMEOUT);
318 printk (KERN_INFO PFX "timeout value must be 1<=timeout<=63, using %d\n",
319 WATCHDOG_TIMEOUT);
322 if (!request_region(wdt_io, 1, WATCHDOG_NAME)) {
323 printk (KERN_ERR PFX "I/O address 0x%04x already in use\n",
324 wdt_io);
325 ret = -EIO;
326 goto out;
329 w83627hf_init();
331 ret = register_reboot_notifier(&wdt_notifier);
332 if (ret != 0) {
333 printk (KERN_ERR PFX "cannot register reboot notifier (err=%d)\n",
334 ret);
335 goto unreg_regions;
338 ret = misc_register(&wdt_miscdev);
339 if (ret != 0) {
340 printk (KERN_ERR PFX "cannot register miscdev on minor=%d (err=%d)\n",
341 WATCHDOG_MINOR, ret);
342 goto unreg_reboot;
345 printk (KERN_INFO PFX "initialized. timeout=%d sec (nowayout=%d)\n",
346 timeout, nowayout);
348 out:
349 return ret;
350 unreg_reboot:
351 unregister_reboot_notifier(&wdt_notifier);
352 unreg_regions:
353 release_region(wdt_io, 1);
354 goto out;
357 static void __exit
358 wdt_exit(void)
360 misc_deregister(&wdt_miscdev);
361 unregister_reboot_notifier(&wdt_notifier);
362 release_region(wdt_io,1);
365 module_init(wdt_init);
366 module_exit(wdt_exit);
368 MODULE_LICENSE("GPL");
369 MODULE_AUTHOR("Pádraig Brady <P@draigBrady.com>");
370 MODULE_DESCRIPTION("w83627hf WDT driver");
371 MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR);