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 #ifdef CONFIG_WATCHDOG_NOWAYOUT
58 static int nowayout = 1;
59 #else
60 static int nowayout = 0;
61 #endif
62
63 module_param(nowayout, int, 0);
64 MODULE_PARM_DESC(nowayout, "Watchdog cannot be stopped once started (default=CONFIG_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 outb_p(0x87, WDT_EFER); /* Enter extended function mode */
78 outb_p(0x87, WDT_EFER); /* Again according to manual */
79
80 outb_p(0x07, WDT_EFER); /* point to logical device number reg */
81 outb_p(0x08, WDT_EFDR); /* select logical device 8 (GPIO2) */
82 outb_p(0x30, WDT_EFER); /* select CR30 */
83 outb_p(0x01, WDT_EFDR); /* set bit 0 to activate GPIO2 */
84 }
85
86 static void
87 w83627hf_unselect_wd_register(void)
88 {
89 outb_p(0xAA, WDT_EFER); /* Leave extended function mode */
90 }
91
92 /* tyan motherboards seem to set F5 to 0x4C ?
93 * So explicitly init to appropriate value. */
94 static void
95 w83627hf_init(void)
96 {
97 unsigned char t;
98
99 w83627hf_select_wd_register();
100
101 outb_p(0xF5, WDT_EFER); /* Select CRF5 */
102 t=inb_p(WDT_EFDR); /* read CRF5 */
103 t&=~0x0C; /* set second mode & disable keyboard turning off watchdog */
104 outb_p(t, WDT_EFDR); /* Write back to CRF5 */
105
106 w83627hf_unselect_wd_register();
107 }
108
109 static void
110 wdt_ctrl(int timeout)
111 {
112 w83627hf_select_wd_register();
113
114 outb_p(0xF6, WDT_EFER); /* Select CRF6 */
115 outb_p(timeout, WDT_EFDR); /* Write Timeout counter to CRF6 */
116
117 w83627hf_unselect_wd_register();
118 }
119
120 static int
121 wdt_ping(void)
122 {
123 wdt_ctrl(timeout);
124 return 0;
125 }
126
127 static int
128 wdt_disable(void)
129 {
130 wdt_ctrl(0);
131 return 0;
132 }
133
134 static int
135 wdt_set_heartbeat(int t)
136 {
137 if ((t < 1) || (t > 63))
138 return -EINVAL;
139
140 timeout = t;
141 return 0;
142 }
143
144 static ssize_t
145 wdt_write(struct file *file, const char __user *buf, size_t count, loff_t *ppos)
146 {
147 if (count) {
148 if (!nowayout) {
149 size_t i;
150
151 expect_close = 0;
152
153 for (i = 0; i != count; i++) {
154 char c;
155 if (get_user(c, buf+i))
156 return -EFAULT;
157 if (c == 'V')
158 expect_close = 42;
159 }
160 }
161 wdt_ping();
162 }
163 return count;
164 }
165
166 static int
167 wdt_ioctl(struct inode *inode, struct file *file, unsigned int cmd,
168 unsigned long arg)
169 {
170 void __user *argp = (void __user *)arg;
171 int __user *p = argp;
172 int new_timeout;
173 static struct watchdog_info ident = {
174 .options = WDIOF_KEEPALIVEPING | WDIOF_SETTIMEOUT | WDIOF_MAGICCLOSE,
175 .firmware_version = 1,
176 .identity = "W83627HF WDT",
177 };
178
179 switch (cmd) {
180 case WDIOC_GETSUPPORT:
181 if (copy_to_user(argp, &ident, sizeof(ident)))
182 return -EFAULT;
183 break;
184
185 case WDIOC_GETSTATUS:
186 case WDIOC_GETBOOTSTATUS:
187 return put_user(0, p);
188
189 case WDIOC_KEEPALIVE:
190 wdt_ping();
191 break;
192
193 case WDIOC_SETTIMEOUT:
194 if (get_user(new_timeout, p))
195 return -EFAULT;
196 if (wdt_set_heartbeat(new_timeout))
197 return -EINVAL;
198 wdt_ping();
199 /* Fall */
200
201 case WDIOC_GETTIMEOUT:
202 return put_user(timeout, p);
203
204 case WDIOC_SETOPTIONS:
205 {
206 int options, retval = -EINVAL;
207
208 if (get_user(options, p))
209 return -EFAULT;
210
211 if (options & WDIOS_DISABLECARD) {
212 wdt_disable();
213 retval = 0;
214 }
215
216 if (options & WDIOS_ENABLECARD) {
217 wdt_ping();
218 retval = 0;
219 }
220
221 return retval;
222 }
223
224 default:
225 return -ENOIOCTLCMD;
226 }
227 return 0;
228 }
229
230 static int
231 wdt_open(struct inode *inode, struct file *file)
232 {
233 if (test_and_set_bit(0, &wdt_is_open))
234 return -EBUSY;
235 /*
236 * Activate
237 */
238
239 wdt_ping();
240 return nonseekable_open(inode, file);
241 }
242
243 static int
244 wdt_close(struct inode *inode, struct file *file)
245 {
246 if (expect_close == 42) {
247 wdt_disable();
248 } else {
249 printk(KERN_CRIT PFX "Unexpected close, not stopping watchdog!\n");
250 wdt_ping();
251 }
252 expect_close = 0;
253 clear_bit(0, &wdt_is_open);
254 return 0;
255 }
256
257 /*
258 * Notifier for system down
259 */
260
261 static int
262 wdt_notify_sys(struct notifier_block *this, unsigned long code,
263 void *unused)
264 {
265 if (code == SYS_DOWN || code == SYS_HALT) {
266 /* Turn the WDT off */
267 wdt_disable();
268 }
269 return NOTIFY_DONE;
270 }
271
272 /*
273 * Kernel Interfaces
274 */
275
276 static struct file_operations wdt_fops = {
277 .owner = THIS_MODULE,
278 .llseek = no_llseek,
279 .write = wdt_write,
280 .ioctl = wdt_ioctl,
281 .open = wdt_open,
282 .release = wdt_close,
283 };
284
285 static struct miscdevice wdt_miscdev = {
286 .minor = WATCHDOG_MINOR,
287 .name = "watchdog",
288 .fops = &wdt_fops,
289 };
290
291 /*
292 * The WDT needs to learn about soft shutdowns in order to
293 * turn the timebomb registers off.
294 */
295
296 static struct notifier_block wdt_notifier = {
297 .notifier_call = wdt_notify_sys,
298 };
299
300 static int __init
301 wdt_init(void)
302 {
303 int ret;
304
305 printk(KERN_INFO "WDT driver for the Winbond(TM) W83627HF Super I/O chip initialising.\n");
306
307 if (wdt_set_heartbeat(timeout)) {
308 wdt_set_heartbeat(WATCHDOG_TIMEOUT);
309 printk (KERN_INFO PFX "timeout value must be 1<=timeout<=63, using %d\n",
310 WATCHDOG_TIMEOUT);
311 }
312
313 if (!request_region(wdt_io, 1, WATCHDOG_NAME)) {
314 printk (KERN_ERR PFX "I/O address 0x%04x already in use\n",
315 wdt_io);
316 ret = -EIO;
317 goto out;
318 }
319
320 w83627hf_init();
321
322 ret = register_reboot_notifier(&wdt_notifier);
323 if (ret != 0) {
324 printk (KERN_ERR PFX "cannot register reboot notifier (err=%d)\n",
325 ret);
326 goto unreg_regions;
327 }
328
329 ret = misc_register(&wdt_miscdev);
330 if (ret != 0) {
331 printk (KERN_ERR PFX "cannot register miscdev on minor=%d (err=%d)\n",
332 WATCHDOG_MINOR, ret);
333 goto unreg_reboot;
334 }
335
336 printk (KERN_INFO PFX "initialized. timeout=%d sec (nowayout=%d)\n",
337 timeout, nowayout);
338
339 out:
340 return ret;
341 unreg_reboot:
342 unregister_reboot_notifier(&wdt_notifier);
343 unreg_regions:
344 release_region(wdt_io, 1);
345 goto out;
346 }
347
348 static void __exit
349 wdt_exit(void)
350 {
351 misc_deregister(&wdt_miscdev);
352 unregister_reboot_notifier(&wdt_notifier);
353 release_region(wdt_io,1);
354 }
355
356 module_init(wdt_init);
357 module_exit(wdt_exit);
358
359 MODULE_LICENSE("GPL");
360 MODULE_AUTHOR("Pádraig Brady <P@draigBrady.com>");
361 MODULE_DESCRIPTION("w38627hf WDT driver");
362 MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR);
363
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