Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/sparc-2.6
[linux-2.6] / drivers / watchdog / w83697ug_wdt.c
1 /*
2  *      w83697ug/uf WDT driver
3  *
4  *      (c) Copyright 2008 Flemming Fransen <ff@nrvissing.net>
5  *              reused original code to supoprt w83697ug/uf.
6  *
7  *      Based on w83627hf_wdt.c which is based on advantechwdt.c
8  *      which is based on wdt.c.
9  *      Original copyright messages:
10  *
11  *      (c) Copyright 2007 Vlad Drukker <vlad@storewiz.com>
12  *              added support for W83627THF.
13  *
14  *      (c) Copyright 2003 Pádraig Brady <P@draigBrady.com>
15  *
16  *      (c) Copyright 2000-2001 Marek Michalkiewicz <marekm@linux.org.pl>
17  *
18  *      (c) Copyright 1996 Alan Cox <alan@redhat.com>, All Rights Reserved.
19  *                              http://www.redhat.com
20  *
21  *      This program is free software; you can redistribute it and/or
22  *      modify it under the terms of the GNU General Public License
23  *      as published by the Free Software Foundation; either version
24  *      2 of the License, or (at your option) any later version.
25  *
26  *      Neither Alan Cox nor CymruNet Ltd. admit liability nor provide
27  *      warranty for any of this software. This material is provided
28  *      "AS-IS" and at no charge.
29  *
30  *      (c) Copyright 1995    Alan Cox <alan@redhat.com>
31  */
32
33 #include <linux/module.h>
34 #include <linux/moduleparam.h>
35 #include <linux/types.h>
36 #include <linux/miscdevice.h>
37 #include <linux/watchdog.h>
38 #include <linux/fs.h>
39 #include <linux/ioport.h>
40 #include <linux/notifier.h>
41 #include <linux/reboot.h>
42 #include <linux/init.h>
43 #include <linux/spinlock.h>
44 #include <linux/io.h>
45 #include <linux/uaccess.h>
46
47 #include <asm/system.h>
48
49 #define WATCHDOG_NAME "w83697ug/uf WDT"
50 #define PFX WATCHDOG_NAME ": "
51 #define WATCHDOG_TIMEOUT 60             /* 60 sec default timeout */
52
53 static unsigned long wdt_is_open;
54 static char expect_close;
55 static DEFINE_SPINLOCK(io_lock);
56
57 static int wdt_io = 0x2e;
58 module_param(wdt_io, int, 0);
59 MODULE_PARM_DESC(wdt_io, "w83697ug/uf WDT io port (default 0x2e)");
60
61 static int timeout = WATCHDOG_TIMEOUT;  /* in seconds */
62 module_param(timeout, int, 0);
63 MODULE_PARM_DESC(timeout,
64         "Watchdog timeout in seconds. 1<= timeout <=255 (default="
65                                 __MODULE_STRING(WATCHDOG_TIMEOUT) ")");
66
67 static int nowayout = WATCHDOG_NOWAYOUT;
68 module_param(nowayout, int, 0);
69 MODULE_PARM_DESC(nowayout,
70         "Watchdog cannot be stopped once started (default="
71                                 __MODULE_STRING(WATCHDOG_NOWAYOUT) ")");
72
73 /*
74  *      Kernel methods.
75  */
76
77 #define WDT_EFER (wdt_io+0)   /* Extended Function Enable Registers */
78 #define WDT_EFIR (wdt_io+0)   /* Extended Function Index Register
79                                                         (same as EFER) */
80 #define WDT_EFDR (WDT_EFIR+1) /* Extended Function Data Register */
81
82 static void w83697ug_select_wd_register(void)
83 {
84         unsigned char c;
85         unsigned char version;
86
87         outb_p(0x87, WDT_EFER); /* Enter extended function mode */
88         outb_p(0x87, WDT_EFER); /* Again according to manual */
89
90         outb(0x20, WDT_EFER);   /* check chip version   */
91         version = inb(WDT_EFDR);
92
93         if (version == 0x68) {  /* W83697UG             */
94                 printk(KERN_INFO PFX "Watchdog chip version 0x%02x = "
95                         "W83697UG/UF found at 0x%04x\n", version, wdt_io);
96
97                 outb_p(0x2b, WDT_EFER);
98                 c = inb_p(WDT_EFDR);    /* select WDT0 */
99                 c &= ~0x04;
100                 outb_p(0x2b, WDT_EFER);
101                 outb_p(c, WDT_EFDR);    /* set pin118 to WDT0 */
102
103         } else {
104                 printk(KERN_ERR PFX "No W83697UG/UF could be found\n");
105                 return;
106         }
107
108         outb_p(0x07, WDT_EFER); /* point to logical device number reg */
109         outb_p(0x08, WDT_EFDR); /* select logical device 8 (GPIO2) */
110         outb_p(0x30, WDT_EFER); /* select CR30 */
111         c = inb_p(WDT_EFDR);
112         outb_p(c || 0x01, WDT_EFDR); /* set bit 0 to activate GPIO2 */
113 }
114
115 static void w83697ug_unselect_wd_register(void)
116 {
117         outb_p(0xAA, WDT_EFER); /* Leave extended function mode */
118 }
119
120 static void w83697ug_init(void)
121 {
122         unsigned char t;
123
124         w83697ug_select_wd_register();
125
126         outb_p(0xF6, WDT_EFER); /* Select CRF6 */
127         t = inb_p(WDT_EFDR);    /* read CRF6 */
128         if (t != 0) {
129                 printk(KERN_INFO PFX "Watchdog already running."
130                         " Resetting timeout to %d sec\n", timeout);
131                 outb_p(timeout, WDT_EFDR);    /* Write back to CRF6 */
132         }
133         outb_p(0xF5, WDT_EFER); /* Select CRF5 */
134         t = inb_p(WDT_EFDR);    /* read CRF5 */
135         t &= ~0x0C;             /* set second mode &
136                                         disable keyboard turning off watchdog */
137         outb_p(t, WDT_EFDR);    /* Write back to CRF5 */
138
139         w83697ug_unselect_wd_register();
140 }
141
142 static void wdt_ctrl(int timeout)
143 {
144         spin_lock(&io_lock);
145
146         w83697ug_select_wd_register();
147
148         outb_p(0xF4, WDT_EFER);    /* Select CRF4 */
149         outb_p(timeout, WDT_EFDR); /* Write Timeout counter to CRF4 */
150
151         w83697ug_unselect_wd_register();
152
153         spin_unlock(&io_lock);
154 }
155
156 static int wdt_ping(void)
157 {
158         wdt_ctrl(timeout);
159         return 0;
160 }
161
162 static int wdt_disable(void)
163 {
164         wdt_ctrl(0);
165         return 0;
166 }
167
168 static int wdt_set_heartbeat(int t)
169 {
170         if (t < 1 || t > 255)
171                 return -EINVAL;
172
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 |
206                                         WDIOF_SETTIMEOUT |
207                                         WDIOF_MAGICCLOSE,
208                 .firmware_version =     1,
209                 .identity =             "W83697UG WDT",
210         };
211
212         switch (cmd) {
213         case WDIOC_GETSUPPORT:
214                 if (copy_to_user(argp, &ident, sizeof(ident)))
215                         return -EFAULT;
216                 break;
217
218         case WDIOC_GETSTATUS:
219         case WDIOC_GETBOOTSTATUS:
220                 return put_user(0, p);
221
222         case WDIOC_SETOPTIONS:
223         {
224                 int options, retval = -EINVAL;
225
226                 if (get_user(options, p))
227                         return -EFAULT;
228
229                 if (options & WDIOS_DISABLECARD) {
230                         wdt_disable();
231                         retval = 0;
232                 }
233
234                 if (options & WDIOS_ENABLECARD) {
235                         wdt_ping();
236                         retval = 0;
237                 }
238
239                 return retval;
240         }
241
242         case WDIOC_KEEPALIVE:
243                 wdt_ping();
244                 break;
245
246         case WDIOC_SETTIMEOUT:
247                 if (get_user(new_timeout, p))
248                         return -EFAULT;
249                 if (wdt_set_heartbeat(new_timeout))
250                         return -EINVAL;
251                 wdt_ping();
252                 /* Fall */
253
254         case WDIOC_GETTIMEOUT:
255                 return put_user(timeout, p);
256
257         default:
258                 return -ENOTTY;
259         }
260         return 0;
261 }
262
263 static int wdt_open(struct inode *inode, struct file *file)
264 {
265         if (test_and_set_bit(0, &wdt_is_open))
266                 return -EBUSY;
267         /*
268          *      Activate
269          */
270
271         wdt_ping();
272         return nonseekable_open(inode, file);
273 }
274
275 static int wdt_close(struct inode *inode, struct file *file)
276 {
277         if (expect_close == 42)
278                 wdt_disable();
279         else {
280                 printk(KERN_CRIT PFX
281                         "Unexpected close, not stopping watchdog!\n");
282                 wdt_ping();
283         }
284         expect_close = 0;
285         clear_bit(0, &wdt_is_open);
286         return 0;
287 }
288
289 /*
290  *      Notifier for system down
291  */
292
293 static int wdt_notify_sys(struct notifier_block *this, unsigned long code,
294         void *unused)
295 {
296         if (code == SYS_DOWN || code == SYS_HALT)
297                 wdt_disable();  /* Turn the WDT off */
298
299         return NOTIFY_DONE;
300 }
301
302 /*
303  *      Kernel Interfaces
304  */
305
306 static const struct file_operations wdt_fops = {
307         .owner          = THIS_MODULE,
308         .llseek         = no_llseek,
309         .write          = wdt_write,
310         .unlocked_ioctl = wdt_ioctl,
311         .open           = wdt_open,
312         .release        = wdt_close,
313 };
314
315 static struct miscdevice wdt_miscdev = {
316         .minor = WATCHDOG_MINOR,
317         .name = "watchdog",
318         .fops = &wdt_fops,
319 };
320
321 /*
322  *      The WDT needs to learn about soft shutdowns in order to
323  *      turn the timebomb registers off.
324  */
325
326 static struct notifier_block wdt_notifier = {
327         .notifier_call = wdt_notify_sys,
328 };
329
330 static int __init wdt_init(void)
331 {
332         int ret;
333
334         printk(KERN_INFO "WDT driver for the Winbond(TM) W83697UG/UF Super I/O chip initialising.\n");
335
336         if (wdt_set_heartbeat(timeout)) {
337                 wdt_set_heartbeat(WATCHDOG_TIMEOUT);
338                 printk(KERN_INFO PFX
339                         "timeout value must be 1<=timeout<=255, using %d\n",
340                         WATCHDOG_TIMEOUT);
341         }
342
343         if (!request_region(wdt_io, 1, WATCHDOG_NAME)) {
344                 printk(KERN_ERR PFX "I/O address 0x%04x already in use\n",
345                         wdt_io);
346                 ret = -EIO;
347                 goto out;
348         }
349
350         w83697ug_init();
351
352         ret = register_reboot_notifier(&wdt_notifier);
353         if (ret != 0) {
354                 printk(KERN_ERR PFX
355                         "cannot register reboot notifier (err=%d)\n", ret);
356                 goto unreg_regions;
357         }
358
359         ret = misc_register(&wdt_miscdev);
360         if (ret != 0) {
361                 printk(KERN_ERR PFX
362                         "cannot register miscdev on minor=%d (err=%d)\n",
363                         WATCHDOG_MINOR, ret);
364                 goto unreg_reboot;
365         }
366
367         printk(KERN_INFO PFX "initialized. timeout=%d sec (nowayout=%d)\n",
368                 timeout, nowayout);
369
370 out:
371         return ret;
372 unreg_reboot:
373         unregister_reboot_notifier(&wdt_notifier);
374 unreg_regions:
375         release_region(wdt_io, 1);
376         goto out;
377 }
378
379 static void __exit wdt_exit(void)
380 {
381         misc_deregister(&wdt_miscdev);
382         unregister_reboot_notifier(&wdt_notifier);
383         release_region(wdt_io, 1);
384 }
385
386 module_init(wdt_init);
387 module_exit(wdt_exit);
388
389 MODULE_LICENSE("GPL");
390 MODULE_AUTHOR("Flemming Frandsen <ff@nrvissing.net>");
391 MODULE_DESCRIPTION("w83697ug/uf WDT driver");
392 MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR);