1 /*
2 * w83627hf/thf WDT driver
3 *
4 * (c) Copyright 2007 Vlad Drukker <vlad@storewiz.com>
5 * added support for W83627THF.
6 *
7 * (c) Copyright 2003,2007 P�draig Brady <P@draigBrady.com>
8 *
9 * Based on advantechwdt.c which is based on wdt.c.
10 * Original copyright messages:
11 *
12 * (c) Copyright 2000-2001 Marek Michalkiewicz <marekm@linux.org.pl>
13 *
14 * (c) Copyright 1996 Alan Cox <alan@lxorguk.ukuu.org.uk>,
15 * All Rights Reserved.
16 *
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.
21 *
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.
25 *
26 * (c) Copyright 1995 Alan Cox <alan@lxorguk.ukuu.org.uk>
27 */
28
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>
42
43 #include <asm/system.h>
44
45 #define WATCHDOG_NAME "w83627hf/thf/hg/dhg WDT"
46 #define PFX WATCHDOG_NAME ": "
47 #define WATCHDOG_TIMEOUT 60 /* 60 sec default timeout */
48
49 static unsigned long wdt_is_open;
50 static char expect_close;
51 static DEFINE_SPINLOCK(io_lock);
52
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)");
57
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) ".");
63
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) ")");
69
70 /*
71 * Kernel methods.
72 */
73
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 */
78
w83627hf_select_wd_register(void)79 static void w83627hf_select_wd_register(void)
80 {
81 unsigned char c;
82 outb_p(0x87, WDT_EFER); /* Enter extended function mode */
83 outb_p(0x87, WDT_EFER); /* Again according to manual */
84
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 || c == 0xa0) { /* W83627EHF / W83627DHG */
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 */
97 }
98
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 */
103 }
104
w83627hf_unselect_wd_register(void)105 static void w83627hf_unselect_wd_register(void)
106 {
107 outb_p(0xAA, WDT_EFER); /* Leave extended function mode */
108 }
109
110 /* tyan motherboards seem to set F5 to 0x4C ?
111 * So explicitly init to appropriate value. */
112
w83627hf_init(void)113 static void w83627hf_init(void)
114 {
115 unsigned char t;
116
117 w83627hf_select_wd_register();
118
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 */
126 }
127
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 t |= 0x02; /* enable the WDTO# output low pulse
133 to the KBRST# pin (PIN60) */
134 outb_p(t, WDT_EFDR); /* Write back to CRF5 */
135
136 outb_p(0xF7, WDT_EFER); /* Select CRF7 */
137 t = inb_p(WDT_EFDR); /* read CRF7 */
138 t &= ~0xC0; /* disable keyboard & mouse turning off
139 watchdog */
140 outb_p(t, WDT_EFDR); /* Write back to CRF7 */
141
142 w83627hf_unselect_wd_register();
143 }
144
wdt_ctrl(int timeout)145 static void wdt_ctrl(int timeout)
146 {
147 spin_lock(&io_lock);
148
149 w83627hf_select_wd_register();
150
151 outb_p(0xF6, WDT_EFER); /* Select CRF6 */
152 outb_p(timeout, WDT_EFDR); /* Write Timeout counter to CRF6 */
153
154 w83627hf_unselect_wd_register();
155
156 spin_unlock(&io_lock);
157 }
158
wdt_ping(void)159 static int wdt_ping(void)
160 {
161 wdt_ctrl(timeout);
162 return 0;
163 }
164
wdt_disable(void)165 static int wdt_disable(void)
166 {
167 wdt_ctrl(0);
168 return 0;
169 }
170
wdt_set_heartbeat(int t)171 static int wdt_set_heartbeat(int t)
172 {
173 if (t < 1 || t > 255)
174 return -EINVAL;
175 timeout = t;
176 return 0;
177 }
178
wdt_write(struct file * file,const char __user * buf,size_t count,loff_t * ppos)179 static ssize_t wdt_write(struct file *file, const char __user *buf,
180 size_t count, loff_t *ppos)
181 {
182 if (count) {
183 if (!nowayout) {
184 size_t i;
185
186 expect_close = 0;
187
188 for (i = 0; i != count; i++) {
189 char c;
190 if (get_user(c, buf + i))
191 return -EFAULT;
192 if (c == 'V')
193 expect_close = 42;
194 }
195 }
196 wdt_ping();
197 }
198 return count;
199 }
200
wdt_ioctl(struct file * file,unsigned int cmd,unsigned long arg)201 static long wdt_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
202 {
203 void __user *argp = (void __user *)arg;
204 int __user *p = argp;
205 int new_timeout;
206 static const struct watchdog_info ident = {
207 .options = WDIOF_KEEPALIVEPING | WDIOF_SETTIMEOUT |
208 WDIOF_MAGICCLOSE,
209 .firmware_version = 1,
210 .identity = "W83627HF WDT",
211 };
212
213 switch (cmd) {
214 case WDIOC_GETSUPPORT:
215 if (copy_to_user(argp, &ident, sizeof(ident)))
216 return -EFAULT;
217 break;
218 case WDIOC_GETSTATUS:
219 case WDIOC_GETBOOTSTATUS:
220 return put_user(0, p);
221 case WDIOC_SETOPTIONS:
222 {
223 int options, retval = -EINVAL;
224
225 if (get_user(options, p))
226 return -EFAULT;
227 if (options & WDIOS_DISABLECARD) {
228 wdt_disable();
229 retval = 0;
230 }
231 if (options & WDIOS_ENABLECARD) {
232 wdt_ping();
233 retval = 0;
234 }
235 return retval;
236 }
237 case WDIOC_KEEPALIVE:
238 wdt_ping();
239 break;
240 case WDIOC_SETTIMEOUT:
241 if (get_user(new_timeout, p))
242 return -EFAULT;
243 if (wdt_set_heartbeat(new_timeout))
244 return -EINVAL;
245 wdt_ping();
246 /* Fall */
247 case WDIOC_GETTIMEOUT:
248 return put_user(timeout, p);
249 default:
250 return -ENOTTY;
251 }
252 return 0;
253 }
254
wdt_open(struct inode * inode,struct file * file)255 static int wdt_open(struct inode *inode, struct file *file)
256 {
257 if (test_and_set_bit(0, &wdt_is_open))
258 return -EBUSY;
259 /*
260 * Activate
261 */
262
263 wdt_ping();
264 return nonseekable_open(inode, file);
265 }
266
wdt_close(struct inode * inode,struct file * file)267 static int wdt_close(struct inode *inode, struct file *file)
268 {
269 if (expect_close == 42)
270 wdt_disable();
271 else {
272 printk(KERN_CRIT PFX
273 "Unexpected close, not stopping watchdog!\n");
274 wdt_ping();
275 }
276 expect_close = 0;
277 clear_bit(0, &wdt_is_open);
278 return 0;
279 }
280
281 /*
282 * Notifier for system down
283 */
284
wdt_notify_sys(struct notifier_block * this,unsigned long code,void * unused)285 static int wdt_notify_sys(struct notifier_block *this, unsigned long code,
286 void *unused)
287 {
288 if (code == SYS_DOWN || code == SYS_HALT)
289 wdt_disable(); /* Turn the WDT off */
290
291 return NOTIFY_DONE;
292 }
293
294 /*
295 * Kernel Interfaces
296 */
297
298 static const struct file_operations wdt_fops = {
299 .owner = THIS_MODULE,
300 .llseek = no_llseek,
301 .write = wdt_write,
302 .unlocked_ioctl = wdt_ioctl,
303 .open = wdt_open,
304 .release = wdt_close,
305 };
306
307 static struct miscdevice wdt_miscdev = {
308 .minor = WATCHDOG_MINOR,
309 .name = "watchdog",
310 .fops = &wdt_fops,
311 };
312
313 /*
314 * The WDT needs to learn about soft shutdowns in order to
315 * turn the timebomb registers off.
316 */
317
318 static struct notifier_block wdt_notifier = {
319 .notifier_call = wdt_notify_sys,
320 };
321
wdt_init(void)322 static int __init wdt_init(void)
323 {
324 int ret;
325
326 printk(KERN_INFO "WDT driver for the Winbond(TM) W83627HF/THF/HG/DHG Super I/O chip initialising.\n");
327
328 if (wdt_set_heartbeat(timeout)) {
329 wdt_set_heartbeat(WATCHDOG_TIMEOUT);
330 printk(KERN_INFO PFX
331 "timeout value must be 1 <= timeout <= 255, using %d\n",
332 WATCHDOG_TIMEOUT);
333 }
334
335 if (!request_region(wdt_io, 1, WATCHDOG_NAME)) {
336 printk(KERN_ERR PFX "I/O address 0x%04x already in use\n",
337 wdt_io);
338 ret = -EIO;
339 goto out;
340 }
341
342 w83627hf_init();
343
344 ret = register_reboot_notifier(&wdt_notifier);
345 if (ret != 0) {
346 printk(KERN_ERR PFX
347 "cannot register reboot notifier (err=%d)\n", ret);
348 goto unreg_regions;
349 }
350
351 ret = misc_register(&wdt_miscdev);
352 if (ret != 0) {
353 printk(KERN_ERR PFX
354 "cannot register miscdev on minor=%d (err=%d)\n",
355 WATCHDOG_MINOR, ret);
356 goto unreg_reboot;
357 }
358
359 printk(KERN_INFO PFX
360 "initialized. timeout=%d sec (nowayout=%d)\n",
361 timeout, nowayout);
362
363 out:
364 return ret;
365 unreg_reboot:
366 unregister_reboot_notifier(&wdt_notifier);
367 unreg_regions:
368 release_region(wdt_io, 1);
369 goto out;
370 }
371
wdt_exit(void)372 static void __exit wdt_exit(void)
373 {
374 misc_deregister(&wdt_miscdev);
375 unregister_reboot_notifier(&wdt_notifier);
376 release_region(wdt_io, 1);
377 }
378
379 module_init(wdt_init);
380 module_exit(wdt_exit);
381
382 MODULE_LICENSE("GPL");
383 MODULE_AUTHOR("P�draig Brady <P@draigBrady.com>");
384 MODULE_DESCRIPTION("w83627hf/thf WDT driver");
385 MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR);
386