59507f609996e32b2591815cf7357923131cff31
[linux-2.6.git] / drivers / watchdog / w83627hf_wdt.c
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 #include <linux/io.h>
41 #include <linux/uaccess.h>
42
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,
61                 "Watchdog timeout in seconds. 1 <= timeout <= 255, default="
62                                 __MODULE_STRING(WATCHDOG_TIMEOUT) ".");
63
64 static int nowayout = WATCHDOG_NOWAYOUT;
65 module_param(nowayout, int, 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
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         }
93
94         outb_p(0x07, WDT_EFER); /* point to logical device number reg */
95         outb_p(0x08, WDT_EFDR); /* select logical device 8 (GPIO2) */
96         outb_p(0x30, WDT_EFER); /* select CR30 */
97         outb_p(0x01, WDT_EFDR); /* set bit 0 to activate GPIO2 */
98 }
99
100 static void w83627hf_unselect_wd_register(void)
101 {
102         outb_p(0xAA, WDT_EFER); /* Leave extended function mode */
103 }
104
105 /* tyan motherboards seem to set F5 to 0x4C ?
106  * So explicitly init to appropriate value. */
107
108 static void w83627hf_init(void)
109 {
110         unsigned char t;
111
112         w83627hf_select_wd_register();
113
114         outb_p(0xF6, WDT_EFER); /* Select CRF6 */
115         t = inb_p(WDT_EFDR);      /* read CRF6 */
116         if (t != 0) {
117                 printk(KERN_INFO PFX
118                      "Watchdog already running. Resetting timeout to %d sec\n",
119                                                                 timeout);
120                 outb_p(timeout, WDT_EFDR);    /* Write back to CRF6 */
121         }
122
123         outb_p(0xF5, WDT_EFER); /* Select CRF5 */
124         t = inb_p(WDT_EFDR);      /* read CRF5 */
125         t &= ~0x0C;               /* set second mode & disable keyboard
126                                     turning off watchdog */
127         outb_p(t, WDT_EFDR);    /* Write back to CRF5 */
128
129         outb_p(0xF7, WDT_EFER); /* Select CRF7 */
130         t = inb_p(WDT_EFDR);      /* read CRF7 */
131         t &= ~0xC0;               /* disable keyboard & mouse turning off
132                                     watchdog */
133         outb_p(t, WDT_EFDR);    /* Write back to CRF7 */
134
135         w83627hf_unselect_wd_register();
136 }
137
138 static void wdt_ctrl(int timeout)
139 {
140         spin_lock(&io_lock);
141
142         w83627hf_select_wd_register();
143
144         outb_p(0xF6, WDT_EFER);    /* Select CRF6 */
145         outb_p(timeout, WDT_EFDR); /* Write Timeout counter to CRF6 */
146
147         w83627hf_unselect_wd_register();
148
149         spin_unlock(&io_lock);
150 }
151
152 static int wdt_ping(void)
153 {
154         wdt_ctrl(timeout);
155         return 0;
156 }
157
158 static int wdt_disable(void)
159 {
160         wdt_ctrl(0);
161         return 0;
162 }
163
164 static int wdt_set_heartbeat(int t)
165 {
166         if (t < 1 || t > 255)
167                 return -EINVAL;
168         timeout = t;
169         return 0;
170 }
171
172 static ssize_t wdt_write(struct file *file, const char __user *buf,
173                                                 size_t count, loff_t *ppos)
174 {
175         if (count) {
176                 if (!nowayout) {
177                         size_t i;
178
179                         expect_close = 0;
180
181                         for (i = 0; i != count; i++) {
182                                 char c;
183                                 if (get_user(c, buf+i))
184                                         return -EFAULT;
185                                 if (c == 'V')
186                                         expect_close = 42;
187                         }
188                 }
189                 wdt_ping();
190         }
191         return count;
192 }
193
194 static long wdt_ioctl(struct file *file, unsigned int cmd, 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 |
201                                                         WDIOF_MAGICCLOSE,
202                 .firmware_version = 1,
203                 .identity = "W83627HF WDT",
204         };
205
206         switch (cmd) {
207         case WDIOC_GETSUPPORT:
208                 if (copy_to_user(argp, &ident, sizeof(ident)))
209                         return -EFAULT;
210                 break;
211         case WDIOC_GETSTATUS:
212         case WDIOC_GETBOOTSTATUS:
213                 return put_user(0, p);
214         case WDIOC_SETOPTIONS:
215         {
216                 int options, retval = -EINVAL;
217
218                 if (get_user(options, p))
219                         return -EFAULT;
220                 if (options & WDIOS_DISABLECARD) {
221                         wdt_disable();
222                         retval = 0;
223                 }
224                 if (options & WDIOS_ENABLECARD) {
225                         wdt_ping();
226                         retval = 0;
227                 }
228                 return retval;
229         }
230         case WDIOC_KEEPALIVE:
231                 wdt_ping();
232                 break;
233         case WDIOC_SETTIMEOUT:
234                 if (get_user(new_timeout, p))
235                         return -EFAULT;
236                 if (wdt_set_heartbeat(new_timeout))
237                         return -EINVAL;
238                 wdt_ping();
239                 /* Fall */
240         case WDIOC_GETTIMEOUT:
241                 return put_user(timeout, p);
242         default:
243                 return -ENOTTY;
244         }
245         return 0;
246 }
247
248 static int wdt_open(struct inode *inode, struct file *file)
249 {
250         if (test_and_set_bit(0, &wdt_is_open))
251                 return -EBUSY;
252         /*
253          *      Activate
254          */
255
256         wdt_ping();
257         return nonseekable_open(inode, file);
258 }
259
260 static int wdt_close(struct inode *inode, struct file *file)
261 {
262         if (expect_close == 42)
263                 wdt_disable();
264         else {
265                 printk(KERN_CRIT PFX
266                         "Unexpected close, not stopping watchdog!\n");
267                 wdt_ping();
268         }
269         expect_close = 0;
270         clear_bit(0, &wdt_is_open);
271         return 0;
272 }
273
274 /*
275  *      Notifier for system down
276  */
277
278 static int wdt_notify_sys(struct notifier_block *this, unsigned long code,
279         void *unused)
280 {
281         if (code == SYS_DOWN || code == SYS_HALT) {
282                 /* Turn the WDT off */
283                 wdt_disable();
284         }
285         return NOTIFY_DONE;
286 }
287
288 /*
289  *      Kernel Interfaces
290  */
291
292 static const struct file_operations wdt_fops = {
293         .owner          = THIS_MODULE,
294         .llseek         = no_llseek,
295         .write          = wdt_write,
296         .unlocked_ioctl = wdt_ioctl,
297         .open           = wdt_open,
298         .release        = wdt_close,
299 };
300
301 static struct miscdevice wdt_miscdev = {
302         .minor = WATCHDOG_MINOR,
303         .name = "watchdog",
304         .fops = &wdt_fops,
305 };
306
307 /*
308  *      The WDT needs to learn about soft shutdowns in order to
309  *      turn the timebomb registers off.
310  */
311
312 static struct notifier_block wdt_notifier = {
313         .notifier_call = wdt_notify_sys,
314 };
315
316 static int __init wdt_init(void)
317 {
318         int ret;
319
320         printk(KERN_INFO "WDT driver for the Winbond(TM) W83627HF/THF/HG Super I/O chip initialising.\n");
321
322         if (wdt_set_heartbeat(timeout)) {
323                 wdt_set_heartbeat(WATCHDOG_TIMEOUT);
324                 printk(KERN_INFO PFX
325                      "timeout value must be 1 <= timeout <= 255, using %d\n",
326                                 WATCHDOG_TIMEOUT);
327         }
328
329         if (!request_region(wdt_io, 1, WATCHDOG_NAME)) {
330                 printk(KERN_ERR PFX "I/O address 0x%04x already in use\n",
331                         wdt_io);
332                 ret = -EIO;
333                 goto out;
334         }
335
336         w83627hf_init();
337
338         ret = register_reboot_notifier(&wdt_notifier);
339         if (ret != 0) {
340                 printk(KERN_ERR PFX
341                         "cannot register reboot notifier (err=%d)\n", ret);
342                 goto unreg_regions;
343         }
344
345         ret = misc_register(&wdt_miscdev);
346         if (ret != 0) {
347                 printk(KERN_ERR PFX
348                         "cannot register miscdev on minor=%d (err=%d)\n",
349                                                         WATCHDOG_MINOR, ret);
350                 goto unreg_reboot;
351         }
352
353         printk(KERN_INFO PFX
354                         "initialized. timeout=%d sec (nowayout=%d)\n",
355                                                         timeout, nowayout);
356
357 out:
358         return ret;
359 unreg_reboot:
360         unregister_reboot_notifier(&wdt_notifier);
361 unreg_regions:
362         release_region(wdt_io, 1);
363         goto out;
364 }
365
366 static void __exit wdt_exit(void)
367 {
368         misc_deregister(&wdt_miscdev);
369         unregister_reboot_notifier(&wdt_notifier);
370         release_region(wdt_io, 1);
371 }
372
373 module_init(wdt_init);
374 module_exit(wdt_exit);
375
376 MODULE_LICENSE("GPL");
377 MODULE_AUTHOR("Pádraig Brady <P@draigBrady.com>");
378 MODULE_DESCRIPTION("w83627hf/thf WDT driver");
379 MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR);