Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/sparc-2.6
[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@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 #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         } else if (c == 0x88) { /* W83627EHF */
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
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
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                 printk(KERN_INFO PFX
123                      "Watchdog already running. Resetting timeout to %d sec\n",
124                                                                 timeout);
125                 outb_p(timeout, WDT_EFDR);    /* Write back to CRF6 */
126         }
127
128         outb_p(0xF5, WDT_EFER); /* Select CRF5 */
129         t = inb_p(WDT_EFDR);      /* read CRF5 */
130         t &= ~0x0C;               /* set second mode & disable keyboard
131                                     turning off watchdog */
132         outb_p(t, WDT_EFDR);    /* Write back to CRF5 */
133
134         outb_p(0xF7, WDT_EFER); /* Select CRF7 */
135         t = inb_p(WDT_EFDR);      /* read CRF7 */
136         t &= ~0xC0;               /* disable keyboard & mouse turning off
137                                     watchdog */
138         outb_p(t, WDT_EFDR);    /* Write back to CRF7 */
139
140         w83627hf_unselect_wd_register();
141 }
142
143 static void wdt_ctrl(int timeout)
144 {
145         spin_lock(&io_lock);
146
147         w83627hf_select_wd_register();
148
149         outb_p(0xF6, WDT_EFER);    /* Select CRF6 */
150         outb_p(timeout, WDT_EFDR); /* Write Timeout counter to CRF6 */
151
152         w83627hf_unselect_wd_register();
153
154         spin_unlock(&io_lock);
155 }
156
157 static int wdt_ping(void)
158 {
159         wdt_ctrl(timeout);
160         return 0;
161 }
162
163 static int wdt_disable(void)
164 {
165         wdt_ctrl(0);
166         return 0;
167 }
168
169 static int wdt_set_heartbeat(int t)
170 {
171         if (t < 1 || t > 255)
172                 return -EINVAL;
173         timeout = t;
174         return 0;
175 }
176
177 static ssize_t wdt_write(struct file *file, const char __user *buf,
178                                                 size_t count, loff_t *ppos)
179 {
180         if (count) {
181                 if (!nowayout) {
182                         size_t i;
183
184                         expect_close = 0;
185
186                         for (i = 0; i != count; i++) {
187                                 char c;
188                                 if (get_user(c, buf + i))
189                                         return -EFAULT;
190                                 if (c == 'V')
191                                         expect_close = 42;
192                         }
193                 }
194                 wdt_ping();
195         }
196         return count;
197 }
198
199 static long wdt_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
200 {
201         void __user *argp = (void __user *)arg;
202         int __user *p = argp;
203         int new_timeout;
204         static const struct watchdog_info ident = {
205                 .options = WDIOF_KEEPALIVEPING | WDIOF_SETTIMEOUT |
206                                                         WDIOF_MAGICCLOSE,
207                 .firmware_version = 1,
208                 .identity = "W83627HF WDT",
209         };
210
211         switch (cmd) {
212         case WDIOC_GETSUPPORT:
213                 if (copy_to_user(argp, &ident, sizeof(ident)))
214                         return -EFAULT;
215                 break;
216         case WDIOC_GETSTATUS:
217         case WDIOC_GETBOOTSTATUS:
218                 return put_user(0, p);
219         case WDIOC_SETOPTIONS:
220         {
221                 int options, retval = -EINVAL;
222
223                 if (get_user(options, p))
224                         return -EFAULT;
225                 if (options & WDIOS_DISABLECARD) {
226                         wdt_disable();
227                         retval = 0;
228                 }
229                 if (options & WDIOS_ENABLECARD) {
230                         wdt_ping();
231                         retval = 0;
232                 }
233                 return retval;
234         }
235         case WDIOC_KEEPALIVE:
236                 wdt_ping();
237                 break;
238         case WDIOC_SETTIMEOUT:
239                 if (get_user(new_timeout, p))
240                         return -EFAULT;
241                 if (wdt_set_heartbeat(new_timeout))
242                         return -EINVAL;
243                 wdt_ping();
244                 /* Fall */
245         case WDIOC_GETTIMEOUT:
246                 return put_user(timeout, p);
247         default:
248                 return -ENOTTY;
249         }
250         return 0;
251 }
252
253 static int wdt_open(struct inode *inode, struct file *file)
254 {
255         if (test_and_set_bit(0, &wdt_is_open))
256                 return -EBUSY;
257         /*
258          *      Activate
259          */
260
261         wdt_ping();
262         return nonseekable_open(inode, file);
263 }
264
265 static int wdt_close(struct inode *inode, struct file *file)
266 {
267         if (expect_close == 42)
268                 wdt_disable();
269         else {
270                 printk(KERN_CRIT PFX
271                         "Unexpected close, not stopping watchdog!\n");
272                 wdt_ping();
273         }
274         expect_close = 0;
275         clear_bit(0, &wdt_is_open);
276         return 0;
277 }
278
279 /*
280  *      Notifier for system down
281  */
282
283 static int wdt_notify_sys(struct notifier_block *this, unsigned long code,
284         void *unused)
285 {
286         if (code == SYS_DOWN || code == SYS_HALT)
287                 wdt_disable();  /* Turn the WDT off */
288
289         return NOTIFY_DONE;
290 }
291
292 /*
293  *      Kernel Interfaces
294  */
295
296 static const struct file_operations wdt_fops = {
297         .owner          = THIS_MODULE,
298         .llseek         = no_llseek,
299         .write          = wdt_write,
300         .unlocked_ioctl = wdt_ioctl,
301         .open           = wdt_open,
302         .release        = wdt_close,
303 };
304
305 static struct miscdevice wdt_miscdev = {
306         .minor = WATCHDOG_MINOR,
307         .name = "watchdog",
308         .fops = &wdt_fops,
309 };
310
311 /*
312  *      The WDT needs to learn about soft shutdowns in order to
313  *      turn the timebomb registers off.
314  */
315
316 static struct notifier_block wdt_notifier = {
317         .notifier_call = wdt_notify_sys,
318 };
319
320 static int __init wdt_init(void)
321 {
322         int ret;
323
324         printk(KERN_INFO "WDT driver for the Winbond(TM) W83627HF/THF/HG Super I/O chip initialising.\n");
325
326         if (wdt_set_heartbeat(timeout)) {
327                 wdt_set_heartbeat(WATCHDOG_TIMEOUT);
328                 printk(KERN_INFO PFX
329                      "timeout value must be 1 <= timeout <= 255, using %d\n",
330                                 WATCHDOG_TIMEOUT);
331         }
332
333         if (!request_region(wdt_io, 1, WATCHDOG_NAME)) {
334                 printk(KERN_ERR PFX "I/O address 0x%04x already in use\n",
335                         wdt_io);
336                 ret = -EIO;
337                 goto out;
338         }
339
340         w83627hf_init();
341
342         ret = register_reboot_notifier(&wdt_notifier);
343         if (ret != 0) {
344                 printk(KERN_ERR PFX
345                         "cannot register reboot notifier (err=%d)\n", ret);
346                 goto unreg_regions;
347         }
348
349         ret = misc_register(&wdt_miscdev);
350         if (ret != 0) {
351                 printk(KERN_ERR PFX
352                         "cannot register miscdev on minor=%d (err=%d)\n",
353                                                         WATCHDOG_MINOR, ret);
354                 goto unreg_reboot;
355         }
356
357         printk(KERN_INFO PFX
358                         "initialized. timeout=%d sec (nowayout=%d)\n",
359                                                         timeout, nowayout);
360
361 out:
362         return ret;
363 unreg_reboot:
364         unregister_reboot_notifier(&wdt_notifier);
365 unreg_regions:
366         release_region(wdt_io, 1);
367         goto out;
368 }
369
370 static void __exit wdt_exit(void)
371 {
372         misc_deregister(&wdt_miscdev);
373         unregister_reboot_notifier(&wdt_notifier);
374         release_region(wdt_io, 1);
375 }
376
377 module_init(wdt_init);
378 module_exit(wdt_exit);
379
380 MODULE_LICENSE("GPL");
381 MODULE_AUTHOR("Pádraig Brady <P@draigBrady.com>");
382 MODULE_DESCRIPTION("w83627hf/thf WDT driver");
383 MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR);