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 Pádraig 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@redhat.com>, All Rights Reserved.
15 * http://www.redhat.com
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@redhat.com>
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
41 #include <asm/io.h>
42 #include <asm/uaccess.h>
43 #include <asm/system.h>
44
45 #define WATCHDOG_NAME "w83627hf/thf/hg 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, "Watchdog timeout in seconds. 1<= timeout <=255, default=" __MODULE_STRING(WATCHDOG_TIMEOUT) ".");
61
62 static int nowayout = WATCHDOG_NOWAYOUT;
63 module_param(nowayout, int, 0);
64 MODULE_PARM_DESC(nowayout, "Watchdog cannot be stopped once started (default=" __MODULE_STRING(WATCHDOG_NOWAYOUT) ")");
65
66 /*
67 * Kernel methods.
68 */
69
70 #define WDT_EFER (wdt_io+0) /* Extended Function Enable Registers */
71 #define WDT_EFIR (wdt_io+0) /* Extended Function Index Register (same as EFER) */
72 #define WDT_EFDR (WDT_EFIR+1) /* Extended Function Data Register */
73
74 static void
75 w83627hf_select_wd_register(void)
76 {
77 unsigned char c;
78 outb_p(0x87, WDT_EFER); /* Enter extended function mode */
79 outb_p(0x87, WDT_EFER); /* Again according to manual */
80
81 outb(0x20, WDT_EFER); /* check chip version */
82 c = inb(WDT_EFDR);
83 if (c == 0x82) { /* W83627THF */
84 outb_p(0x2b, WDT_EFER); /* select GPIO3 */
85 c = ((inb_p(WDT_EFDR) & 0xf7) | 0x04); /* select WDT0 */
86 outb_p(0x2b, WDT_EFER);
87 outb_p(c, WDT_EFDR); /* set GPIO3 to WDT0 */
88 }
89
90 outb_p(0x07, WDT_EFER); /* point to logical device number reg */
91 outb_p(0x08, WDT_EFDR); /* select logical device 8 (GPIO2) */
92 outb_p(0x30, WDT_EFER); /* select CR30 */
93 outb_p(0x01, WDT_EFDR); /* set bit 0 to activate GPIO2 */
94 }
95
96 static void
97 w83627hf_unselect_wd_register(void)
98 {
99 outb_p(0xAA, WDT_EFER); /* Leave extended function mode */
100 }
101
102 /* tyan motherboards seem to set F5 to 0x4C ?
103 * So explicitly init to appropriate value. */
104 static void
105 w83627hf_init(void)
106 {
107 unsigned char t;
108
109 w83627hf_select_wd_register();
110
111 outb_p(0xF6, WDT_EFER); /* Select CRF6 */
112 t=inb_p(WDT_EFDR); /* read CRF6 */
113 if (t != 0) {
114 printk (KERN_INFO PFX "Watchdog already running. Resetting timeout to %d sec\n", timeout);
115 outb_p(timeout, WDT_EFDR); /* Write back to CRF6 */
116 }
117
118 outb_p(0xF5, WDT_EFER); /* Select CRF5 */
119 t=inb_p(WDT_EFDR); /* read CRF5 */
120 t&=~0x0C; /* set second mode & disable keyboard turning off watchdog */
121 outb_p(t, WDT_EFDR); /* Write back to CRF5 */
122
123 outb_p(0xF7, WDT_EFER); /* Select CRF7 */
124 t=inb_p(WDT_EFDR); /* read CRF7 */
125 t&=~0xC0; /* disable keyboard & mouse turning off watchdog */
126 outb_p(t, WDT_EFDR); /* Write back to CRF7 */
127
128 w83627hf_unselect_wd_register();
129 }
130
131 static void
132 wdt_ctrl(int timeout)
133 {
134 spin_lock(&io_lock);
135
136 w83627hf_select_wd_register();
137
138 outb_p(0xF6, WDT_EFER); /* Select CRF6 */
139 outb_p(timeout, WDT_EFDR); /* Write Timeout counter to CRF6 */
140
141 w83627hf_unselect_wd_register();
142
143 spin_unlock(&io_lock);
144 }
145
146 static int
147 wdt_ping(void)
148 {
149 wdt_ctrl(timeout);
150 return 0;
151 }
152
153 static int
154 wdt_disable(void)
155 {
156 wdt_ctrl(0);
157 return 0;
158 }
159
160 static int
161 wdt_set_heartbeat(int t)
162 {
163 if ((t < 1) || (t > 255))
164 return -EINVAL;
165
166 timeout = t;
167 return 0;
168 }
169
170 static ssize_t
171 wdt_write(struct file *file, const char __user *buf, size_t count, loff_t *ppos)
172 {
173 if (count) {
174 if (!nowayout) {
175 size_t i;
176
177 expect_close = 0;
178
179 for (i = 0; i != count; i++) {
180 char c;
181 if (get_user(c, buf+i))
182 return -EFAULT;
183 if (c == 'V')
184 expect_close = 42;
185 }
186 }
187 wdt_ping();
188 }
189 return count;
190 }
191
192 static int
193 wdt_ioctl(struct inode *inode, struct file *file, unsigned int cmd,
194 unsigned long arg)
195 {
196 void __user *argp = (void __user *)arg;
197 int __user *p = argp;
198 int new_timeout;
199 static struct watchdog_info ident = {
200 .options = WDIOF_KEEPALIVEPING | WDIOF_SETTIMEOUT | WDIOF_MAGICCLOSE,
201 .firmware_version = 1,
202 .identity = "W83627HF WDT",
203 };
204
205 switch (cmd) {
206 case WDIOC_GETSUPPORT:
207 if (copy_to_user(argp, &ident, sizeof(ident)))
208 return -EFAULT;
209 break;
210
211 case WDIOC_GETSTATUS:
212 case WDIOC_GETBOOTSTATUS:
213 return put_user(0, p);
214
215 case WDIOC_KEEPALIVE:
216 wdt_ping();
217 break;
218
219 case WDIOC_SETTIMEOUT:
220 if (get_user(new_timeout, p))
221 return -EFAULT;
222 if (wdt_set_heartbeat(new_timeout))
223 return -EINVAL;
224 wdt_ping();
225 /* Fall */
226
227 case WDIOC_GETTIMEOUT:
228 return put_user(timeout, p);
229
230 case WDIOC_SETOPTIONS:
231 {
232 int options, retval = -EINVAL;
233
234 if (get_user(options, p))
235 return -EFAULT;
236
237 if (options & WDIOS_DISABLECARD) {
238 wdt_disable();
239 retval = 0;
240 }
241
242 if (options & WDIOS_ENABLECARD) {
243 wdt_ping();
244 retval = 0;
245 }
246
247 return retval;
248 }
249
250 default:
251 return -ENOTTY;
252 }
253 return 0;
254 }
255
256 static int
257 wdt_open(struct inode *inode, struct file *file)
258 {
259 if (test_and_set_bit(0, &wdt_is_open))
260 return -EBUSY;
261 /*
262 * Activate
263 */
264
265 wdt_ping();
266 return nonseekable_open(inode, file);
267 }
268
269 static int
270 wdt_close(struct inode *inode, struct file *file)
271 {
272 if (expect_close == 42) {
273 wdt_disable();
274 } else {
275 printk(KERN_CRIT PFX "Unexpected close, not stopping watchdog!\n");
276 wdt_ping();
277 }
278 expect_close = 0;
279 clear_bit(0, &wdt_is_open);
280 return 0;
281 }
282
283 /*
284 * Notifier for system down
285 */
286
287 static int
288 wdt_notify_sys(struct notifier_block *this, unsigned long code,
289 void *unused)
290 {
291 if (code == SYS_DOWN || code == SYS_HALT) {
292 /* Turn the WDT off */
293 wdt_disable();
294 }
295 return NOTIFY_DONE;
296 }
297
298 /*
299 * Kernel Interfaces
300 */
301
302 static const struct file_operations wdt_fops = {
303 .owner = THIS_MODULE,
304 .llseek = no_llseek,
305 .write = wdt_write,
306 .ioctl = wdt_ioctl,
307 .open = wdt_open,
308 .release = wdt_close,
309 };
310
311 static struct miscdevice wdt_miscdev = {
312 .minor = WATCHDOG_MINOR,
313 .name = "watchdog",
314 .fops = &wdt_fops,
315 };
316
317 /*
318 * The WDT needs to learn about soft shutdowns in order to
319 * turn the timebomb registers off.
320 */
321
322 static struct notifier_block wdt_notifier = {
323 .notifier_call = wdt_notify_sys,
324 };
325
326 static int __init
327 wdt_init(void)
328 {
329 int ret;
330
331 printk(KERN_INFO "WDT driver for the Winbond(TM) W83627HF/THF/HG Super I/O chip initialising.\n");
332
333 if (wdt_set_heartbeat(timeout)) {
334 wdt_set_heartbeat(WATCHDOG_TIMEOUT);
335 printk (KERN_INFO PFX "timeout value must be 1<=timeout<=255, using %d\n",
336 WATCHDOG_TIMEOUT);
337 }
338
339 if (!request_region(wdt_io, 1, WATCHDOG_NAME)) {
340 printk (KERN_ERR PFX "I/O address 0x%04x already in use\n",
341 wdt_io);
342 ret = -EIO;
343 goto out;
344 }
345
346 w83627hf_init();
347
348 ret = register_reboot_notifier(&wdt_notifier);
349 if (ret != 0) {
350 printk (KERN_ERR PFX "cannot register reboot notifier (err=%d)\n",
351 ret);
352 goto unreg_regions;
353 }
354
355 ret = misc_register(&wdt_miscdev);
356 if (ret != 0) {
357 printk (KERN_ERR PFX "cannot register miscdev on minor=%d (err=%d)\n",
358 WATCHDOG_MINOR, ret);
359 goto unreg_reboot;
360 }
361
362 printk (KERN_INFO PFX "initialized. timeout=%d sec (nowayout=%d)\n",
363 timeout, nowayout);
364
365 out:
366 return ret;
367 unreg_reboot:
368 unregister_reboot_notifier(&wdt_notifier);
369 unreg_regions:
370 release_region(wdt_io, 1);
371 goto out;
372 }
373
374 static void __exit
375 wdt_exit(void)
376 {
377 misc_deregister(&wdt_miscdev);
378 unregister_reboot_notifier(&wdt_notifier);
379 release_region(wdt_io,1);
380 }
381
382 module_init(wdt_init);
383 module_exit(wdt_exit);
384
385 MODULE_LICENSE("GPL");
386 MODULE_AUTHOR("Pádraig Brady <P@draigBrady.com>");
387 MODULE_DESCRIPTION("w83627hf/thf WDT driver");
388 MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR);
389
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