Merge tag 'split-asm_system_h-for-linus-20120328' of git://git.kernel.org/pub/scm...
[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 #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
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
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                 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
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
158 static int wdt_ping(void)
159 {
160         wdt_set_time(timeout);
161         return 0;
162 }
163
164 static int wdt_disable(void)
165 {
166         wdt_set_time(0);
167         return 0;
168 }
169
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
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
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
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
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
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
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
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
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);