1 /*
2 * w83627hf WDT driver
3 *
4 * (c) Copyright 2003 Pádraig Brady <P@draigBrady.com>
5 *
6 * Based on advantechwdt.c which is based on wdt.c.
7 * Original copyright messages:
8 *
9 * (c) Copyright 2000-2001 Marek Michalkiewicz <marekm@linux.org.pl>
10 *
11 * (c) Copyright 1996 Alan Cox <alan@redhat.com>, All Rights Reserved.
12 * http://www.redhat.com
13 *
14 * This program is free software; you can redistribute it and/or
15 * modify it under the terms of the GNU General Public License
16 * as published by the Free Software Foundation; either version
17 * 2 of the License, or (at your option) any later version.
18 *
19 * Neither Alan Cox nor CymruNet Ltd. admit liability nor provide
20 * warranty for any of this software. This material is provided
21 * "AS-IS" and at no charge.
22 *
23 * (c) Copyright 1995 Alan Cox <alan@redhat.com>
24 */
25
26 #include <linux/module.h>
27 #include <linux/moduleparam.h>
28 #include <linux/types.h>
29 #include <linux/miscdevice.h>
30 #include <linux/watchdog.h>
31 #include <linux/fs.h>
32 #include <linux/ioport.h>
33 #include <linux/notifier.h>
34 #include <linux/reboot.h>
35 #include <linux/init.h>
36
37 #include <asm/io.h>
38 #include <asm/uaccess.h>
39 #include <asm/system.h>
40
41 #define WATCHDOG_NAME "w83627hf WDT"
42 #define PFX WATCHDOG_NAME ": "
43 #define WATCHDOG_TIMEOUT 60 /* 60 sec default timeout */
44
45 static unsigned long wdt_is_open;
46 static char expect_close;
47
48 /* You must set this - there is no sane way to probe for this board. */
49 static int wdt_io = 0x2E;
50 module_param(wdt_io, int, 0);
51 MODULE_PARM_DESC(wdt_io, "w83627hf WDT io port (default 0x2E)");
52
53 static int timeout = WATCHDOG_TIMEOUT; /* in seconds */
54 module_param(timeout, int, 0);
55 MODULE_PARM_DESC(timeout, "Watchdog timeout in seconds. 1<= timeout <=63, default=" __MODULE_STRING(WATCHDOG_TIMEOUT) ".");
56
57 static int nowayout = WATCHDOG_NOWAYOUT;
58 module_param(nowayout, int, 0);
59 MODULE_PARM_DESC(nowayout, "Watchdog cannot be stopped once started (default=CONFIG_WATCHDOG_NOWAYOUT)");
60
61 /*
62 * Kernel methods.
63 */
64
65 #define WDT_EFER (wdt_io+0) /* Extended Function Enable Registers */
66 #define WDT_EFIR (wdt_io+0) /* Extended Function Index Register (same as EFER) */
67 #define WDT_EFDR (WDT_EFIR+1) /* Extended Function Data Register */
68
69 static void
70 w83627hf_select_wd_register(void)
71 {
72 outb_p(0x87, WDT_EFER); /* Enter extended function mode */
73 outb_p(0x87, WDT_EFER); /* Again according to manual */
74
75 outb_p(0x07, WDT_EFER); /* point to logical device number reg */
76 outb_p(0x08, WDT_EFDR); /* select logical device 8 (GPIO2) */
77 outb_p(0x30, WDT_EFER); /* select CR30 */
78 outb_p(0x01, WDT_EFDR); /* set bit 0 to activate GPIO2 */
79 }
80
81 static void
82 w83627hf_unselect_wd_register(void)
83 {
84 outb_p(0xAA, WDT_EFER); /* Leave extended function mode */
85 }
86
87 /* tyan motherboards seem to set F5 to 0x4C ?
88 * So explicitly init to appropriate value. */
89 static void
90 w83627hf_init(void)
91 {
92 unsigned char t;
93
94 w83627hf_select_wd_register();
95
96 outb_p(0xF6, WDT_EFER); /* Select CRF6 */
97 t=inb_p(WDT_EFDR); /* read CRF6 */
98 if (t != 0) {
99 printk (KERN_INFO PFX "Watchdog already running. Resetting timeout to %d sec\n", timeout);
100 outb_p(timeout, WDT_EFDR); /* Write back to CRF6 */
101 }
102 outb_p(0xF5, WDT_EFER); /* Select CRF5 */
103 t=inb_p(WDT_EFDR); /* read CRF5 */
104 t&=~0x0C; /* set second mode & disable keyboard turning off watchdog */
105 outb_p(t, WDT_EFDR); /* Write back to CRF5 */
106
107 w83627hf_unselect_wd_register();
108 }
109
110 static void
111 wdt_ctrl(int timeout)
112 {
113 w83627hf_select_wd_register();
114
115 outb_p(0xF6, WDT_EFER); /* Select CRF6 */
116 outb_p(timeout, WDT_EFDR); /* Write Timeout counter to CRF6 */
117
118 w83627hf_unselect_wd_register();
119 }
120
121 static int
122 wdt_ping(void)
123 {
124 wdt_ctrl(timeout);
125 return 0;
126 }
127
128 static int
129 wdt_disable(void)
130 {
131 wdt_ctrl(0);
132 return 0;
133 }
134
135 static int
136 wdt_set_heartbeat(int t)
137 {
138 if ((t < 1) || (t > 63))
139 return -EINVAL;
140
141 timeout = t;
142 return 0;
143 }
144
145 static ssize_t
146 wdt_write(struct file *file, const char __user *buf, size_t count, loff_t *ppos)
147 {
148 if (count) {
149 if (!nowayout) {
150 size_t i;
151
152 expect_close = 0;
153
154 for (i = 0; i != count; i++) {
155 char c;
156 if (get_user(c, buf+i))
157 return -EFAULT;
158 if (c == 'V')
159 expect_close = 42;
160 }
161 }
162 wdt_ping();
163 }
164 return count;
165 }
166
167 static int
168 wdt_ioctl(struct inode *inode, struct file *file, unsigned int cmd,
169 unsigned long arg)
170 {
171 void __user *argp = (void __user *)arg;
172 int __user *p = argp;
173 int new_timeout;
174 static struct watchdog_info ident = {
175 .options = WDIOF_KEEPALIVEPING | WDIOF_SETTIMEOUT | WDIOF_MAGICCLOSE,
176 .firmware_version = 1,
177 .identity = "W83627HF WDT",
178 };
179
180 switch (cmd) {
181 case WDIOC_GETSUPPORT:
182 if (copy_to_user(argp, &ident, sizeof(ident)))
183 return -EFAULT;
184 break;
185
186 case WDIOC_GETSTATUS:
187 case WDIOC_GETBOOTSTATUS:
188 return put_user(0, p);
189
190 case WDIOC_KEEPALIVE:
191 wdt_ping();
192 break;
193
194 case WDIOC_SETTIMEOUT:
195 if (get_user(new_timeout, p))
196 return -EFAULT;
197 if (wdt_set_heartbeat(new_timeout))
198 return -EINVAL;
199 wdt_ping();
200 /* Fall */
201
202 case WDIOC_GETTIMEOUT:
203 return put_user(timeout, p);
204
205 case WDIOC_SETOPTIONS:
206 {
207 int options, retval = -EINVAL;
208
209 if (get_user(options, p))
210 return -EFAULT;
211
212 if (options & WDIOS_DISABLECARD) {
213 wdt_disable();
214 retval = 0;
215 }
216
217 if (options & WDIOS_ENABLECARD) {
218 wdt_ping();
219 retval = 0;
220 }
221
222 return retval;
223 }
224
225 default:
226 return -ENOIOCTLCMD;
227 }
228 return 0;
229 }
230
231 static int
232 wdt_open(struct inode *inode, struct file *file)
233 {
234 if (test_and_set_bit(0, &wdt_is_open))
235 return -EBUSY;
236 /*
237 * Activate
238 */
239
240 wdt_ping();
241 return nonseekable_open(inode, file);
242 }
243
244 static int
245 wdt_close(struct inode *inode, struct file *file)
246 {
247 if (expect_close == 42) {
248 wdt_disable();
249 } else {
250 printk(KERN_CRIT PFX "Unexpected close, not stopping watchdog!\n");
251 wdt_ping();
252 }
253 expect_close = 0;
254 clear_bit(0, &wdt_is_open);
255 return 0;
256 }
257
258 /*
259 * Notifier for system down
260 */
261
262 static int
263 wdt_notify_sys(struct notifier_block *this, unsigned long code,
264 void *unused)
265 {
266 if (code == SYS_DOWN || code == SYS_HALT) {
267 /* Turn the WDT off */
268 wdt_disable();
269 }
270 return NOTIFY_DONE;
271 }
272
273 /*
274 * Kernel Interfaces
275 */
276
277 static struct file_operations wdt_fops = {
278 .owner = THIS_MODULE,
279 .llseek = no_llseek,
280 .write = wdt_write,
281 .ioctl = wdt_ioctl,
282 .open = wdt_open,
283 .release = wdt_close,
284 };
285
286 static struct miscdevice wdt_miscdev = {
287 .minor = WATCHDOG_MINOR,
288 .name = "watchdog",
289 .fops = &wdt_fops,
290 };
291
292 /*
293 * The WDT needs to learn about soft shutdowns in order to
294 * turn the timebomb registers off.
295 */
296
297 static struct notifier_block wdt_notifier = {
298 .notifier_call = wdt_notify_sys,
299 };
300
301 static int __init
302 wdt_init(void)
303 {
304 int ret;
305
306 printk(KERN_INFO "WDT driver for the Winbond(TM) W83627HF Super I/O chip initialising.\n");
307
308 if (wdt_set_heartbeat(timeout)) {
309 wdt_set_heartbeat(WATCHDOG_TIMEOUT);
310 printk (KERN_INFO PFX "timeout value must be 1<=timeout<=63, using %d\n",
311 WATCHDOG_TIMEOUT);
312 }
313
314 if (!request_region(wdt_io, 1, WATCHDOG_NAME)) {
315 printk (KERN_ERR PFX "I/O address 0x%04x already in use\n",
316 wdt_io);
317 ret = -EIO;
318 goto out;
319 }
320
321 w83627hf_init();
322
323 ret = register_reboot_notifier(&wdt_notifier);
324 if (ret != 0) {
325 printk (KERN_ERR PFX "cannot register reboot notifier (err=%d)\n",
326 ret);
327 goto unreg_regions;
328 }
329
330 ret = misc_register(&wdt_miscdev);
331 if (ret != 0) {
332 printk (KERN_ERR PFX "cannot register miscdev on minor=%d (err=%d)\n",
333 WATCHDOG_MINOR, ret);
334 goto unreg_reboot;
335 }
336
337 printk (KERN_INFO PFX "initialized. timeout=%d sec (nowayout=%d)\n",
338 timeout, nowayout);
339
340 out:
341 return ret;
342 unreg_reboot:
343 unregister_reboot_notifier(&wdt_notifier);
344 unreg_regions:
345 release_region(wdt_io, 1);
346 goto out;
347 }
348
349 static void __exit
350 wdt_exit(void)
351 {
352 misc_deregister(&wdt_miscdev);
353 unregister_reboot_notifier(&wdt_notifier);
354 release_region(wdt_io,1);
355 }
356
357 module_init(wdt_init);
358 module_exit(wdt_exit);
359
360 MODULE_LICENSE("GPL");
361 MODULE_AUTHOR("Pádraig Brady <P@draigBrady.com>");
362 MODULE_DESCRIPTION("w83627hf WDT driver");
363 MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR);
364
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