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@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 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
30
31 #include <linux/module.h>
32 #include <linux/moduleparam.h>
33 #include <linux/types.h>
34 #include <linux/miscdevice.h>
35 #include <linux/watchdog.h>
36 #include <linux/fs.h>
37 #include <linux/ioport.h>
38 #include <linux/notifier.h>
39 #include <linux/reboot.h>
40 #include <linux/init.h>
41 #include <linux/spinlock.h>
42 #include <linux/io.h>
43 #include <linux/uaccess.h>
44
45
46 #define WATCHDOG_NAME "w83627hf/thf/hg/dhg WDT"
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 bool nowayout = WATCHDOG_NOWAYOUT;
65 module_param(nowayout, bool, 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 pr_info("Watchdog already running. Resetting timeout to %d sec\n",
123 timeout);
124 outb_p(timeout, WDT_EFDR); /* Write back to CRF6 */
125 }
126
127 outb_p(0xF5, WDT_EFER); /* Select CRF5 */
128 t = inb_p(WDT_EFDR); /* read CRF5 */
129 t &= ~0x0C; /* set second mode & disable keyboard
130 turning off watchdog */
131 t |= 0x02; /* enable the WDTO# output low pulse
132 to the KBRST# pin (PIN60) */
133 outb_p(t, WDT_EFDR); /* Write back to CRF5 */
134
135 outb_p(0xF7, WDT_EFER); /* Select CRF7 */
136 t = inb_p(WDT_EFDR); /* read CRF7 */
137 t &= ~0xC0; /* disable keyboard & mouse turning off
138 watchdog */
139 outb_p(t, WDT_EFDR); /* Write back to CRF7 */
140
141 w83627hf_unselect_wd_register();
142 }
143
wdt_set_time(int timeout)144 static void wdt_set_time(int timeout)
145 {
146 spin_lock(&io_lock);
147
148 w83627hf_select_wd_register();
149
150 outb_p(0xF6, WDT_EFER); /* Select CRF6 */
151 outb_p(timeout, WDT_EFDR); /* Write Timeout counter to CRF6 */
152
153 w83627hf_unselect_wd_register();
154
155 spin_unlock(&io_lock);
156 }
157
wdt_ping(void)158 static int wdt_ping(void)
159 {
160 wdt_set_time(timeout);
161 return 0;
162 }
163
wdt_disable(void)164 static int wdt_disable(void)
165 {
166 wdt_set_time(0);
167 return 0;
168 }
169
wdt_set_heartbeat(int t)170 static int wdt_set_heartbeat(int t)
171 {
172 if (t < 1 || t > 255)
173 return -EINVAL;
174 timeout = t;
175 return 0;
176 }
177
wdt_get_time(void)178 static int wdt_get_time(void)
179 {
180 int timeleft;
181
182 spin_lock(&io_lock);
183
184 w83627hf_select_wd_register();
185
186 outb_p(0xF6, WDT_EFER); /* Select CRF6 */
187 timeleft = inb_p(WDT_EFDR); /* Read Timeout counter to CRF6 */
188
189 w83627hf_unselect_wd_register();
190
191 spin_unlock(&io_lock);
192
193 return timeleft;
194 }
195
wdt_write(struct file * file,const char __user * buf,size_t count,loff_t * ppos)196 static ssize_t wdt_write(struct file *file, const char __user *buf,
197 size_t count, loff_t *ppos)
198 {
199 if (count) {
200 if (!nowayout) {
201 size_t i;
202
203 expect_close = 0;
204
205 for (i = 0; i != count; i++) {
206 char c;
207 if (get_user(c, buf + i))
208 return -EFAULT;
209 if (c == 'V')
210 expect_close = 42;
211 }
212 }
213 wdt_ping();
214 }
215 return count;
216 }
217
wdt_ioctl(struct file * file,unsigned int cmd,unsigned long arg)218 static long wdt_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
219 {
220 void __user *argp = (void __user *)arg;
221 int __user *p = argp;
222 int timeval;
223 static const struct watchdog_info ident = {
224 .options = WDIOF_KEEPALIVEPING | WDIOF_SETTIMEOUT |
225 WDIOF_MAGICCLOSE,
226 .firmware_version = 1,
227 .identity = "W83627HF WDT",
228 };
229
230 switch (cmd) {
231 case WDIOC_GETSUPPORT:
232 if (copy_to_user(argp, &ident, sizeof(ident)))
233 return -EFAULT;
234 break;
235 case WDIOC_GETSTATUS:
236 case WDIOC_GETBOOTSTATUS:
237 return put_user(0, p);
238 case WDIOC_SETOPTIONS:
239 {
240 int options, retval = -EINVAL;
241
242 if (get_user(options, p))
243 return -EFAULT;
244 if (options & WDIOS_DISABLECARD) {
245 wdt_disable();
246 retval = 0;
247 }
248 if (options & WDIOS_ENABLECARD) {
249 wdt_ping();
250 retval = 0;
251 }
252 return retval;
253 }
254 case WDIOC_KEEPALIVE:
255 wdt_ping();
256 break;
257 case WDIOC_SETTIMEOUT:
258 if (get_user(timeval, p))
259 return -EFAULT;
260 if (wdt_set_heartbeat(timeval))
261 return -EINVAL;
262 wdt_ping();
263 /* Fall */
264 case WDIOC_GETTIMEOUT:
265 return put_user(timeout, p);
266 case WDIOC_GETTIMELEFT:
267 timeval = wdt_get_time();
268 return put_user(timeval, p);
269 default:
270 return -ENOTTY;
271 }
272 return 0;
273 }
274
wdt_open(struct inode * inode,struct file * file)275 static int wdt_open(struct inode *inode, struct file *file)
276 {
277 if (test_and_set_bit(0, &wdt_is_open))
278 return -EBUSY;
279 /*
280 * Activate
281 */
282
283 wdt_ping();
284 return nonseekable_open(inode, file);
285 }
286
wdt_close(struct inode * inode,struct file * file)287 static int wdt_close(struct inode *inode, struct file *file)
288 {
289 if (expect_close == 42)
290 wdt_disable();
291 else {
292 pr_crit("Unexpected close, not stopping watchdog!\n");
293 wdt_ping();
294 }
295 expect_close = 0;
296 clear_bit(0, &wdt_is_open);
297 return 0;
298 }
299
300 /*
301 * Notifier for system down
302 */
303
wdt_notify_sys(struct notifier_block * this,unsigned long code,void * unused)304 static int wdt_notify_sys(struct notifier_block *this, unsigned long code,
305 void *unused)
306 {
307 if (code == SYS_DOWN || code == SYS_HALT)
308 wdt_disable(); /* Turn the WDT off */
309
310 return NOTIFY_DONE;
311 }
312
313 /*
314 * Kernel Interfaces
315 */
316
317 static const struct file_operations wdt_fops = {
318 .owner = THIS_MODULE,
319 .llseek = no_llseek,
320 .write = wdt_write,
321 .unlocked_ioctl = wdt_ioctl,
322 .open = wdt_open,
323 .release = wdt_close,
324 };
325
326 static struct miscdevice wdt_miscdev = {
327 .minor = WATCHDOG_MINOR,
328 .name = "watchdog",
329 .fops = &wdt_fops,
330 };
331
332 /*
333 * The WDT needs to learn about soft shutdowns in order to
334 * turn the timebomb registers off.
335 */
336
337 static struct notifier_block wdt_notifier = {
338 .notifier_call = wdt_notify_sys,
339 };
340
wdt_init(void)341 static int __init wdt_init(void)
342 {
343 int ret;
344
345 pr_info("WDT driver for the Winbond(TM) W83627HF/THF/HG/DHG Super I/O chip initialising\n");
346
347 if (wdt_set_heartbeat(timeout)) {
348 wdt_set_heartbeat(WATCHDOG_TIMEOUT);
349 pr_info("timeout value must be 1 <= timeout <= 255, using %d\n",
350 WATCHDOG_TIMEOUT);
351 }
352
353 if (!request_region(wdt_io, 1, WATCHDOG_NAME)) {
354 pr_err("I/O address 0x%04x already in use\n", wdt_io);
355 ret = -EIO;
356 goto out;
357 }
358
359 w83627hf_init();
360
361 ret = register_reboot_notifier(&wdt_notifier);
362 if (ret != 0) {
363 pr_err("cannot register reboot notifier (err=%d)\n", ret);
364 goto unreg_regions;
365 }
366
367 ret = misc_register(&wdt_miscdev);
368 if (ret != 0) {
369 pr_err("cannot register miscdev on minor=%d (err=%d)\n",
370 WATCHDOG_MINOR, ret);
371 goto unreg_reboot;
372 }
373
374 pr_info("initialized. timeout=%d sec (nowayout=%d)\n",
375 timeout, nowayout);
376
377 out:
378 return ret;
379 unreg_reboot:
380 unregister_reboot_notifier(&wdt_notifier);
381 unreg_regions:
382 release_region(wdt_io, 1);
383 goto out;
384 }
385
wdt_exit(void)386 static void __exit wdt_exit(void)
387 {
388 misc_deregister(&wdt_miscdev);
389 unregister_reboot_notifier(&wdt_notifier);
390 release_region(wdt_io, 1);
391 }
392
393 module_init(wdt_init);
394 module_exit(wdt_exit);
395
396 MODULE_LICENSE("GPL");
397 MODULE_AUTHOR("Pádraig Brady <P@draigBrady.com>");
398 MODULE_DESCRIPTION("w83627hf/thf WDT driver");
399 MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR);
400