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[linux-2.6/linux-acpi-2.6/ibm-acpi-2.6.git] / drivers / watchdog / w83627hf_wdt.c
blob0f5288df0091730299f59bb9685962492a2dca89
1 /*
2 * w83627hf/thf WDT driver
4 * (c) Copyright 2007 Vlad Drukker <vlad@storewiz.com>
5 * added support for W83627THF.
7 * (c) Copyright 2003,2007 Pádraig Brady <P@draigBrady.com>
9 * Based on advantechwdt.c which is based on wdt.c.
10 * Original copyright messages:
12 * (c) Copyright 2000-2001 Marek Michalkiewicz <marekm@linux.org.pl>
14 * (c) Copyright 1996 Alan Cox <alan@lxorguk.ukuu.org.uk>,
15 * All Rights Reserved.
17 * This program is free software; you can redistribute it and/or
18 * modify it under the terms of the GNU General Public License
19 * as published by the Free Software Foundation; either version
20 * 2 of the License, or (at your option) any later version.
22 * Neither Alan Cox nor CymruNet Ltd. admit liability nor provide
23 * warranty for any of this software. This material is provided
24 * "AS-IS" and at no charge.
26 * (c) Copyright 1995 Alan Cox <alan@lxorguk.ukuu.org.uk>
29 #include <linux/module.h>
30 #include <linux/moduleparam.h>
31 #include <linux/types.h>
32 #include <linux/miscdevice.h>
33 #include <linux/watchdog.h>
34 #include <linux/fs.h>
35 #include <linux/ioport.h>
36 #include <linux/notifier.h>
37 #include <linux/reboot.h>
38 #include <linux/init.h>
39 #include <linux/spinlock.h>
40 #include <linux/io.h>
41 #include <linux/uaccess.h>
43 #include <asm/system.h>
45 #define WATCHDOG_NAME "w83627hf/thf/hg WDT"
46 #define PFX WATCHDOG_NAME ": "
47 #define WATCHDOG_TIMEOUT 60 /* 60 sec default timeout */
49 static unsigned long wdt_is_open;
50 static char expect_close;
51 static DEFINE_SPINLOCK(io_lock);
53 /* You must set this - there is no sane way to probe for this board. */
54 static int wdt_io = 0x2E;
55 module_param(wdt_io, int, 0);
56 MODULE_PARM_DESC(wdt_io, "w83627hf/thf WDT io port (default 0x2E)");
58 static int timeout = WATCHDOG_TIMEOUT; /* in seconds */
59 module_param(timeout, int, 0);
60 MODULE_PARM_DESC(timeout,
61 "Watchdog timeout in seconds. 1 <= timeout <= 255, default="
62 __MODULE_STRING(WATCHDOG_TIMEOUT) ".");
64 static int nowayout = WATCHDOG_NOWAYOUT;
65 module_param(nowayout, int, 0);
66 MODULE_PARM_DESC(nowayout,
67 "Watchdog cannot be stopped once started (default="
68 __MODULE_STRING(WATCHDOG_NOWAYOUT) ")");
71 * Kernel methods.
74 #define WDT_EFER (wdt_io+0) /* Extended Function Enable Registers */
75 #define WDT_EFIR (wdt_io+0) /* Extended Function Index Register
76 (same as EFER) */
77 #define WDT_EFDR (WDT_EFIR+1) /* Extended Function Data Register */
79 static void w83627hf_select_wd_register(void)
81 unsigned char c;
82 outb_p(0x87, WDT_EFER); /* Enter extended function mode */
83 outb_p(0x87, WDT_EFER); /* Again according to manual */
85 outb(0x20, WDT_EFER); /* check chip version */
86 c = inb(WDT_EFDR);
87 if (c == 0x82) { /* W83627THF */
88 outb_p(0x2b, WDT_EFER); /* select GPIO3 */
89 c = ((inb_p(WDT_EFDR) & 0xf7) | 0x04); /* select WDT0 */
90 outb_p(0x2b, WDT_EFER);
91 outb_p(c, WDT_EFDR); /* set GPIO3 to WDT0 */
92 } else if (c == 0x88) { /* W83627EHF */
93 outb_p(0x2d, WDT_EFER); /* select GPIO5 */
94 c = inb_p(WDT_EFDR) & ~0x01; /* PIN77 -> WDT0# */
95 outb_p(0x2d, WDT_EFER);
96 outb_p(c, WDT_EFDR); /* set GPIO5 to WDT0 */
99 outb_p(0x07, WDT_EFER); /* point to logical device number reg */
100 outb_p(0x08, WDT_EFDR); /* select logical device 8 (GPIO2) */
101 outb_p(0x30, WDT_EFER); /* select CR30 */
102 outb_p(0x01, WDT_EFDR); /* set bit 0 to activate GPIO2 */
105 static void w83627hf_unselect_wd_register(void)
107 outb_p(0xAA, WDT_EFER); /* Leave extended function mode */
110 /* tyan motherboards seem to set F5 to 0x4C ?
111 * So explicitly init to appropriate value. */
113 static void w83627hf_init(void)
115 unsigned char t;
117 w83627hf_select_wd_register();
119 outb_p(0xF6, WDT_EFER); /* Select CRF6 */
120 t = inb_p(WDT_EFDR); /* read CRF6 */
121 if (t != 0) {
122 printk(KERN_INFO PFX
123 "Watchdog already running. Resetting timeout to %d sec\n",
124 timeout);
125 outb_p(timeout, WDT_EFDR); /* Write back to CRF6 */
128 outb_p(0xF5, WDT_EFER); /* Select CRF5 */
129 t = inb_p(WDT_EFDR); /* read CRF5 */
130 t &= ~0x0C; /* set second mode & disable keyboard
131 turning off watchdog */
132 outb_p(t, WDT_EFDR); /* Write back to CRF5 */
134 outb_p(0xF7, WDT_EFER); /* Select CRF7 */
135 t = inb_p(WDT_EFDR); /* read CRF7 */
136 t &= ~0xC0; /* disable keyboard & mouse turning off
137 watchdog */
138 outb_p(t, WDT_EFDR); /* Write back to CRF7 */
140 w83627hf_unselect_wd_register();
143 static void wdt_ctrl(int timeout)
145 spin_lock(&io_lock);
147 w83627hf_select_wd_register();
149 outb_p(0xF6, WDT_EFER); /* Select CRF6 */
150 outb_p(timeout, WDT_EFDR); /* Write Timeout counter to CRF6 */
152 w83627hf_unselect_wd_register();
154 spin_unlock(&io_lock);
157 static int wdt_ping(void)
159 wdt_ctrl(timeout);
160 return 0;
163 static int wdt_disable(void)
165 wdt_ctrl(0);
166 return 0;
169 static int wdt_set_heartbeat(int t)
171 if (t < 1 || t > 255)
172 return -EINVAL;
173 timeout = t;
174 return 0;
177 static ssize_t wdt_write(struct file *file, const char __user *buf,
178 size_t count, loff_t *ppos)
180 if (count) {
181 if (!nowayout) {
182 size_t i;
184 expect_close = 0;
186 for (i = 0; i != count; i++) {
187 char c;
188 if (get_user(c, buf + i))
189 return -EFAULT;
190 if (c == 'V')
191 expect_close = 42;
194 wdt_ping();
196 return count;
199 static long wdt_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
201 void __user *argp = (void __user *)arg;
202 int __user *p = argp;
203 int new_timeout;
204 static const struct watchdog_info ident = {
205 .options = WDIOF_KEEPALIVEPING | WDIOF_SETTIMEOUT |
206 WDIOF_MAGICCLOSE,
207 .firmware_version = 1,
208 .identity = "W83627HF WDT",
211 switch (cmd) {
212 case WDIOC_GETSUPPORT:
213 if (copy_to_user(argp, &ident, sizeof(ident)))
214 return -EFAULT;
215 break;
216 case WDIOC_GETSTATUS:
217 case WDIOC_GETBOOTSTATUS:
218 return put_user(0, p);
219 case WDIOC_SETOPTIONS:
221 int options, retval = -EINVAL;
223 if (get_user(options, p))
224 return -EFAULT;
225 if (options & WDIOS_DISABLECARD) {
226 wdt_disable();
227 retval = 0;
229 if (options & WDIOS_ENABLECARD) {
230 wdt_ping();
231 retval = 0;
233 return retval;
235 case WDIOC_KEEPALIVE:
236 wdt_ping();
237 break;
238 case WDIOC_SETTIMEOUT:
239 if (get_user(new_timeout, p))
240 return -EFAULT;
241 if (wdt_set_heartbeat(new_timeout))
242 return -EINVAL;
243 wdt_ping();
244 /* Fall */
245 case WDIOC_GETTIMEOUT:
246 return put_user(timeout, p);
247 default:
248 return -ENOTTY;
250 return 0;
253 static int wdt_open(struct inode *inode, struct file *file)
255 if (test_and_set_bit(0, &wdt_is_open))
256 return -EBUSY;
258 * Activate
261 wdt_ping();
262 return nonseekable_open(inode, file);
265 static int wdt_close(struct inode *inode, struct file *file)
267 if (expect_close == 42)
268 wdt_disable();
269 else {
270 printk(KERN_CRIT PFX
271 "Unexpected close, not stopping watchdog!\n");
272 wdt_ping();
274 expect_close = 0;
275 clear_bit(0, &wdt_is_open);
276 return 0;
280 * Notifier for system down
283 static int wdt_notify_sys(struct notifier_block *this, unsigned long code,
284 void *unused)
286 if (code == SYS_DOWN || code == SYS_HALT)
287 wdt_disable(); /* Turn the WDT off */
289 return NOTIFY_DONE;
293 * Kernel Interfaces
296 static const struct file_operations wdt_fops = {
297 .owner = THIS_MODULE,
298 .llseek = no_llseek,
299 .write = wdt_write,
300 .unlocked_ioctl = wdt_ioctl,
301 .open = wdt_open,
302 .release = wdt_close,
305 static struct miscdevice wdt_miscdev = {
306 .minor = WATCHDOG_MINOR,
307 .name = "watchdog",
308 .fops = &wdt_fops,
312 * The WDT needs to learn about soft shutdowns in order to
313 * turn the timebomb registers off.
316 static struct notifier_block wdt_notifier = {
317 .notifier_call = wdt_notify_sys,
320 static int __init wdt_init(void)
322 int ret;
324 printk(KERN_INFO "WDT driver for the Winbond(TM) W83627HF/THF/HG Super I/O chip initialising.\n");
326 if (wdt_set_heartbeat(timeout)) {
327 wdt_set_heartbeat(WATCHDOG_TIMEOUT);
328 printk(KERN_INFO PFX
329 "timeout value must be 1 <= timeout <= 255, using %d\n",
330 WATCHDOG_TIMEOUT);
333 if (!request_region(wdt_io, 1, WATCHDOG_NAME)) {
334 printk(KERN_ERR PFX "I/O address 0x%04x already in use\n",
335 wdt_io);
336 ret = -EIO;
337 goto out;
340 w83627hf_init();
342 ret = register_reboot_notifier(&wdt_notifier);
343 if (ret != 0) {
344 printk(KERN_ERR PFX
345 "cannot register reboot notifier (err=%d)\n", ret);
346 goto unreg_regions;
349 ret = misc_register(&wdt_miscdev);
350 if (ret != 0) {
351 printk(KERN_ERR PFX
352 "cannot register miscdev on minor=%d (err=%d)\n",
353 WATCHDOG_MINOR, ret);
354 goto unreg_reboot;
357 printk(KERN_INFO PFX
358 "initialized. timeout=%d sec (nowayout=%d)\n",
359 timeout, nowayout);
361 out:
362 return ret;
363 unreg_reboot:
364 unregister_reboot_notifier(&wdt_notifier);
365 unreg_regions:
366 release_region(wdt_io, 1);
367 goto out;
370 static void __exit wdt_exit(void)
372 misc_deregister(&wdt_miscdev);
373 unregister_reboot_notifier(&wdt_notifier);
374 release_region(wdt_io, 1);
377 module_init(wdt_init);
378 module_exit(wdt_exit);
380 MODULE_LICENSE("GPL");
381 MODULE_AUTHOR("Pádraig Brady <P@draigBrady.com>");
382 MODULE_DESCRIPTION("w83627hf/thf WDT driver");
383 MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR);