1 /*
2 * w83697ug/uf WDT driver
3 *
4 * (c) Copyright 2008 Flemming Fransen <ff@nrvissing.net>
5 * reused original code to support w83697ug/uf.
6 *
7 * Based on w83627hf_wdt.c which is based on advantechwdt.c
8 * which is based on wdt.c.
9 * Original copyright messages:
10 *
11 * (c) Copyright 2007 Vlad Drukker <vlad@storewiz.com>
12 * added support for W83627THF.
13 *
14 * (c) Copyright 2003 Pádraig Brady <P@draigBrady.com>
15 *
16 * (c) Copyright 2000-2001 Marek Michalkiewicz <marekm@linux.org.pl>
17 *
18 * (c) Copyright 1996 Alan Cox <alan@redhat.com>, All Rights Reserved.
19 * http://www.redhat.com
20 *
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.
25 *
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.
29 *
30 * (c) Copyright 1995 Alan Cox <alan@redhat.com>
31 */
32
33 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
34
35 #include <linux/module.h>
36 #include <linux/moduleparam.h>
37 #include <linux/types.h>
38 #include <linux/miscdevice.h>
39 #include <linux/watchdog.h>
40 #include <linux/fs.h>
41 #include <linux/ioport.h>
42 #include <linux/notifier.h>
43 #include <linux/reboot.h>
44 #include <linux/init.h>
45 #include <linux/spinlock.h>
46 #include <linux/io.h>
47 #include <linux/uaccess.h>
48
49
50 #define WATCHDOG_NAME "w83697ug/uf WDT"
51 #define WATCHDOG_TIMEOUT 60 /* 60 sec default timeout */
52
53 static unsigned long wdt_is_open;
54 static char expect_close;
55 static DEFINE_SPINLOCK(io_lock);
56
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)");
60
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) ")");
66
67 static bool nowayout = WATCHDOG_NOWAYOUT;
68 module_param(nowayout, bool, 0);
69 MODULE_PARM_DESC(nowayout,
70 "Watchdog cannot be stopped once started (default="
71 __MODULE_STRING(WATCHDOG_NOWAYOUT) ")");
72
73 /*
74 * Kernel methods.
75 */
76
77 #define WDT_EFER (wdt_io+0) /* Extended Function Enable Registers */
78 #define WDT_EFIR (wdt_io+0) /* Extended Function Index Register
79 (same as EFER) */
80 #define WDT_EFDR (WDT_EFIR+1) /* Extended Function Data Register */
81
w83697ug_select_wd_register(void)82 static int w83697ug_select_wd_register(void)
83 {
84 unsigned char c;
85 unsigned char version;
86
87 outb_p(0x87, WDT_EFER); /* Enter extended function mode */
88 outb_p(0x87, WDT_EFER); /* Again according to manual */
89
90 outb(0x20, WDT_EFER); /* check chip version */
91 version = inb(WDT_EFDR);
92
93 if (version == 0x68) { /* W83697UG */
94 pr_info("Watchdog chip version 0x%02x = W83697UG/UF found at 0x%04x\n",
95 version, wdt_io);
96
97 outb_p(0x2b, WDT_EFER);
98 c = inb_p(WDT_EFDR); /* select WDT0 */
99 c &= ~0x04;
100 outb_p(0x2b, WDT_EFER);
101 outb_p(c, WDT_EFDR); /* set pin118 to WDT0 */
102
103 } else {
104 pr_err("No W83697UG/UF could be found\n");
105 return -ENODEV;
106 }
107
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 */
111 c = inb_p(WDT_EFDR);
112 outb_p(c | 0x01, WDT_EFDR); /* set bit 0 to activate GPIO2 */
113
114 return 0;
115 }
116
w83697ug_unselect_wd_register(void)117 static void w83697ug_unselect_wd_register(void)
118 {
119 outb_p(0xAA, WDT_EFER); /* Leave extended function mode */
120 }
121
w83697ug_init(void)122 static int w83697ug_init(void)
123 {
124 int ret;
125 unsigned char t;
126
127 ret = w83697ug_select_wd_register();
128 if (ret != 0)
129 return ret;
130
131 outb_p(0xF6, WDT_EFER); /* Select CRF6 */
132 t = inb_p(WDT_EFDR); /* read CRF6 */
133 if (t != 0) {
134 pr_info("Watchdog already running. Resetting timeout to %d sec\n",
135 timeout);
136 outb_p(timeout, WDT_EFDR); /* Write back to CRF6 */
137 }
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 */
143
144 w83697ug_unselect_wd_register();
145 return 0;
146 }
147
wdt_ctrl(int timeout)148 static void wdt_ctrl(int timeout)
149 {
150 spin_lock(&io_lock);
151
152 if (w83697ug_select_wd_register() < 0) {
153 spin_unlock(&io_lock);
154 return;
155 }
156
157 outb_p(0xF4, WDT_EFER); /* Select CRF4 */
158 outb_p(timeout, WDT_EFDR); /* Write Timeout counter to CRF4 */
159
160 w83697ug_unselect_wd_register();
161
162 spin_unlock(&io_lock);
163 }
164
wdt_ping(void)165 static int wdt_ping(void)
166 {
167 wdt_ctrl(timeout);
168 return 0;
169 }
170
wdt_disable(void)171 static int wdt_disable(void)
172 {
173 wdt_ctrl(0);
174 return 0;
175 }
176
wdt_set_heartbeat(int t)177 static int wdt_set_heartbeat(int t)
178 {
179 if (t < 1 || t > 255)
180 return -EINVAL;
181
182 timeout = t;
183 return 0;
184 }
185
wdt_write(struct file * file,const char __user * buf,size_t count,loff_t * ppos)186 static ssize_t wdt_write(struct file *file, const char __user *buf,
187 size_t count, loff_t *ppos)
188 {
189 if (count) {
190 if (!nowayout) {
191 size_t i;
192
193 expect_close = 0;
194
195 for (i = 0; i != count; i++) {
196 char c;
197 if (get_user(c, buf + i))
198 return -EFAULT;
199 if (c == 'V')
200 expect_close = 42;
201 }
202 }
203 wdt_ping();
204 }
205 return count;
206 }
207
wdt_ioctl(struct file * file,unsigned int cmd,unsigned long arg)208 static long wdt_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
209 {
210 void __user *argp = (void __user *)arg;
211 int __user *p = argp;
212 int new_timeout;
213 static const struct watchdog_info ident = {
214 .options = WDIOF_KEEPALIVEPING |
215 WDIOF_SETTIMEOUT |
216 WDIOF_MAGICCLOSE,
217 .firmware_version = 1,
218 .identity = "W83697UG WDT",
219 };
220
221 switch (cmd) {
222 case WDIOC_GETSUPPORT:
223 if (copy_to_user(argp, &ident, sizeof(ident)))
224 return -EFAULT;
225 break;
226
227 case WDIOC_GETSTATUS:
228 case WDIOC_GETBOOTSTATUS:
229 return put_user(0, p);
230
231 case WDIOC_SETOPTIONS:
232 {
233 int options, retval = -EINVAL;
234
235 if (get_user(options, p))
236 return -EFAULT;
237
238 if (options & WDIOS_DISABLECARD) {
239 wdt_disable();
240 retval = 0;
241 }
242
243 if (options & WDIOS_ENABLECARD) {
244 wdt_ping();
245 retval = 0;
246 }
247
248 return retval;
249 }
250
251 case WDIOC_KEEPALIVE:
252 wdt_ping();
253 break;
254
255 case WDIOC_SETTIMEOUT:
256 if (get_user(new_timeout, p))
257 return -EFAULT;
258 if (wdt_set_heartbeat(new_timeout))
259 return -EINVAL;
260 wdt_ping();
261 /* Fall */
262
263 case WDIOC_GETTIMEOUT:
264 return put_user(timeout, p);
265
266 default:
267 return -ENOTTY;
268 }
269 return 0;
270 }
271
wdt_open(struct inode * inode,struct file * file)272 static int wdt_open(struct inode *inode, struct file *file)
273 {
274 if (test_and_set_bit(0, &wdt_is_open))
275 return -EBUSY;
276 /*
277 * Activate
278 */
279
280 wdt_ping();
281 return nonseekable_open(inode, file);
282 }
283
wdt_close(struct inode * inode,struct file * file)284 static int wdt_close(struct inode *inode, struct file *file)
285 {
286 if (expect_close == 42)
287 wdt_disable();
288 else {
289 pr_crit("Unexpected close, not stopping watchdog!\n");
290 wdt_ping();
291 }
292 expect_close = 0;
293 clear_bit(0, &wdt_is_open);
294 return 0;
295 }
296
297 /*
298 * Notifier for system down
299 */
300
wdt_notify_sys(struct notifier_block * this,unsigned long code,void * unused)301 static int wdt_notify_sys(struct notifier_block *this, unsigned long code,
302 void *unused)
303 {
304 if (code == SYS_DOWN || code == SYS_HALT)
305 wdt_disable(); /* Turn the WDT off */
306
307 return NOTIFY_DONE;
308 }
309
310 /*
311 * Kernel Interfaces
312 */
313
314 static const struct file_operations wdt_fops = {
315 .owner = THIS_MODULE,
316 .llseek = no_llseek,
317 .write = wdt_write,
318 .unlocked_ioctl = wdt_ioctl,
319 .open = wdt_open,
320 .release = wdt_close,
321 };
322
323 static struct miscdevice wdt_miscdev = {
324 .minor = WATCHDOG_MINOR,
325 .name = "watchdog",
326 .fops = &wdt_fops,
327 };
328
329 /*
330 * The WDT needs to learn about soft shutdowns in order to
331 * turn the timebomb registers off.
332 */
333
334 static struct notifier_block wdt_notifier = {
335 .notifier_call = wdt_notify_sys,
336 };
337
wdt_init(void)338 static int __init wdt_init(void)
339 {
340 int ret;
341
342 pr_info("WDT driver for the Winbond(TM) W83697UG/UF Super I/O chip initialising\n");
343
344 if (wdt_set_heartbeat(timeout)) {
345 wdt_set_heartbeat(WATCHDOG_TIMEOUT);
346 pr_info("timeout value must be 1<=timeout<=255, using %d\n",
347 WATCHDOG_TIMEOUT);
348 }
349
350 if (!request_region(wdt_io, 1, WATCHDOG_NAME)) {
351 pr_err("I/O address 0x%04x already in use\n", wdt_io);
352 ret = -EIO;
353 goto out;
354 }
355
356 ret = w83697ug_init();
357 if (ret != 0)
358 goto unreg_regions;
359
360 ret = register_reboot_notifier(&wdt_notifier);
361 if (ret != 0) {
362 pr_err("cannot register reboot notifier (err=%d)\n", ret);
363 goto unreg_regions;
364 }
365
366 ret = misc_register(&wdt_miscdev);
367 if (ret != 0) {
368 pr_err("cannot register miscdev on minor=%d (err=%d)\n",
369 WATCHDOG_MINOR, ret);
370 goto unreg_reboot;
371 }
372
373 pr_info("initialized. timeout=%d sec (nowayout=%d)\n",
374 timeout, nowayout);
375
376 out:
377 return ret;
378 unreg_reboot:
379 unregister_reboot_notifier(&wdt_notifier);
380 unreg_regions:
381 release_region(wdt_io, 1);
382 goto out;
383 }
384
wdt_exit(void)385 static void __exit wdt_exit(void)
386 {
387 misc_deregister(&wdt_miscdev);
388 unregister_reboot_notifier(&wdt_notifier);
389 release_region(wdt_io, 1);
390 }
391
392 module_init(wdt_init);
393 module_exit(wdt_exit);
394
395 MODULE_LICENSE("GPL");
396 MODULE_AUTHOR("Flemming Frandsen <ff@nrvissing.net>");
397 MODULE_DESCRIPTION("w83697ug/uf WDT driver");
398 MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR);
399