libata: implement and use SHT initializers
[linux-2.6] / drivers / watchdog / advantechwdt.c
1 /*
2  *      Advantech Single Board Computer WDT driver
3  *
4  *      (c) Copyright 2000-2001 Marek Michalkiewicz <marekm@linux.org.pl>
5  *
6  *      Based on acquirewdt.c which is based on wdt.c.
7  *      Original copyright messages:
8  *
9  *      (c) Copyright 1996 Alan Cox <alan@redhat.com>, All Rights Reserved.
10  *                              http://www.redhat.com
11  *
12  *      This program is free software; you can redistribute it and/or
13  *      modify it under the terms of the GNU General Public License
14  *      as published by the Free Software Foundation; either version
15  *      2 of the License, or (at your option) any later version.
16  *
17  *      Neither Alan Cox nor CymruNet Ltd. admit liability nor provide
18  *      warranty for any of this software. This material is provided
19  *      "AS-IS" and at no charge.
20  *
21  *      (c) Copyright 1995    Alan Cox <alan@redhat.com>
22  *
23  *      14-Dec-2001 Matt Domsch <Matt_Domsch@dell.com>
24  *          Added nowayout module option to override CONFIG_WATCHDOG_NOWAYOUT
25  *
26  *      16-Oct-2002 Rob Radez <rob@osinvestor.com>
27  *          Clean up ioctls, clean up init + exit, add expect close support,
28  *          add wdt_start and wdt_stop as parameters.
29  */
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/platform_device.h>
39 #include <linux/init.h>
40
41 #include <asm/io.h>
42 #include <asm/uaccess.h>
43 #include <asm/system.h>
44
45 #define DRV_NAME "advantechwdt"
46 #define PFX DRV_NAME ": "
47 #define WATCHDOG_NAME "Advantech WDT"
48 #define WATCHDOG_TIMEOUT 60             /* 60 sec default timeout */
49
50 static struct platform_device *advwdt_platform_device;  /* the watchdog platform device */
51 static unsigned long advwdt_is_open;
52 static char adv_expect_close;
53
54 /*
55  *      You must set these - there is no sane way to probe for this board.
56  *
57  *      To enable or restart, write the timeout value in seconds (1 to 63)
58  *      to I/O port wdt_start.  To disable, read I/O port wdt_stop.
59  *      Both are 0x443 for most boards (tested on a PCA-6276VE-00B1), but
60  *      check your manual (at least the PCA-6159 seems to be different -
61  *      the manual says wdt_stop is 0x43, not 0x443).
62  *      (0x43 is also a write-only control register for the 8254 timer!)
63  */
64
65 static int wdt_stop = 0x443;
66 module_param(wdt_stop, int, 0);
67 MODULE_PARM_DESC(wdt_stop, "Advantech WDT 'stop' io port (default 0x443)");
68
69 static int wdt_start = 0x443;
70 module_param(wdt_start, int, 0);
71 MODULE_PARM_DESC(wdt_start, "Advantech WDT 'start' io port (default 0x443)");
72
73 static int timeout = WATCHDOG_TIMEOUT;  /* in seconds */
74 module_param(timeout, int, 0);
75 MODULE_PARM_DESC(timeout, "Watchdog timeout in seconds. 1<= timeout <=63, default=" __MODULE_STRING(WATCHDOG_TIMEOUT) ".");
76
77 static int nowayout = WATCHDOG_NOWAYOUT;
78 module_param(nowayout, int, 0);
79 MODULE_PARM_DESC(nowayout, "Watchdog cannot be stopped once started (default=" __MODULE_STRING(WATCHDOG_NOWAYOUT) ")");
80
81 /*
82  *      Watchdog Operations
83  */
84
85 static void
86 advwdt_ping(void)
87 {
88         /* Write a watchdog value */
89         outb_p(timeout, wdt_start);
90 }
91
92 static void
93 advwdt_disable(void)
94 {
95         inb_p(wdt_stop);
96 }
97
98 static int
99 advwdt_set_heartbeat(int t)
100 {
101         if ((t < 1) || (t > 63))
102                 return -EINVAL;
103
104         timeout = t;
105         return 0;
106 }
107
108 /*
109  *      /dev/watchdog handling
110  */
111
112 static ssize_t
113 advwdt_write(struct file *file, const char __user *buf, size_t count, loff_t *ppos)
114 {
115         if (count) {
116                 if (!nowayout) {
117                         size_t i;
118
119                         adv_expect_close = 0;
120
121                         for (i = 0; i != count; i++) {
122                                 char c;
123                                 if (get_user(c, buf+i))
124                                         return -EFAULT;
125                                 if (c == 'V')
126                                         adv_expect_close = 42;
127                         }
128                 }
129                 advwdt_ping();
130         }
131         return count;
132 }
133
134 static int
135 advwdt_ioctl(struct inode *inode, struct file *file, unsigned int cmd,
136           unsigned long arg)
137 {
138         int new_timeout;
139         void __user *argp = (void __user *)arg;
140         int __user *p = argp;
141         static struct watchdog_info ident = {
142                 .options = WDIOF_KEEPALIVEPING | WDIOF_SETTIMEOUT | WDIOF_MAGICCLOSE,
143                 .firmware_version = 1,
144                 .identity = WATCHDOG_NAME,
145         };
146
147         switch (cmd) {
148         case WDIOC_GETSUPPORT:
149           if (copy_to_user(argp, &ident, sizeof(ident)))
150             return -EFAULT;
151           break;
152
153         case WDIOC_GETSTATUS:
154         case WDIOC_GETBOOTSTATUS:
155           return put_user(0, p);
156
157         case WDIOC_KEEPALIVE:
158           advwdt_ping();
159           break;
160
161         case WDIOC_SETTIMEOUT:
162           if (get_user(new_timeout, p))
163                   return -EFAULT;
164           if (advwdt_set_heartbeat(new_timeout))
165                   return -EINVAL;
166           advwdt_ping();
167           /* Fall */
168
169         case WDIOC_GETTIMEOUT:
170           return put_user(timeout, p);
171
172         case WDIOC_SETOPTIONS:
173         {
174           int options, retval = -EINVAL;
175
176           if (get_user(options, p))
177             return -EFAULT;
178
179           if (options & WDIOS_DISABLECARD) {
180             advwdt_disable();
181             retval = 0;
182           }
183
184           if (options & WDIOS_ENABLECARD) {
185             advwdt_ping();
186             retval = 0;
187           }
188
189           return retval;
190         }
191
192         default:
193           return -ENOTTY;
194         }
195         return 0;
196 }
197
198 static int
199 advwdt_open(struct inode *inode, struct file *file)
200 {
201         if (test_and_set_bit(0, &advwdt_is_open))
202                 return -EBUSY;
203         /*
204          *      Activate
205          */
206
207         advwdt_ping();
208         return nonseekable_open(inode, file);
209 }
210
211 static int
212 advwdt_close(struct inode *inode, struct file *file)
213 {
214         if (adv_expect_close == 42) {
215                 advwdt_disable();
216         } else {
217                 printk(KERN_CRIT PFX "Unexpected close, not stopping watchdog!\n");
218                 advwdt_ping();
219         }
220         clear_bit(0, &advwdt_is_open);
221         adv_expect_close = 0;
222         return 0;
223 }
224
225 /*
226  *      Kernel Interfaces
227  */
228
229 static const struct file_operations advwdt_fops = {
230         .owner          = THIS_MODULE,
231         .llseek         = no_llseek,
232         .write          = advwdt_write,
233         .ioctl          = advwdt_ioctl,
234         .open           = advwdt_open,
235         .release        = advwdt_close,
236 };
237
238 static struct miscdevice advwdt_miscdev = {
239         .minor  = WATCHDOG_MINOR,
240         .name   = "watchdog",
241         .fops   = &advwdt_fops,
242 };
243
244 /*
245  *      Init & exit routines
246  */
247
248 static int __devinit
249 advwdt_probe(struct platform_device *dev)
250 {
251         int ret;
252
253         if (wdt_stop != wdt_start) {
254                 if (!request_region(wdt_stop, 1, WATCHDOG_NAME)) {
255                         printk (KERN_ERR PFX "I/O address 0x%04x already in use\n",
256                                 wdt_stop);
257                         ret = -EIO;
258                         goto out;
259                 }
260         }
261
262         if (!request_region(wdt_start, 1, WATCHDOG_NAME)) {
263                 printk (KERN_ERR PFX "I/O address 0x%04x already in use\n",
264                         wdt_start);
265                 ret = -EIO;
266                 goto unreg_stop;
267         }
268
269         /* Check that the heartbeat value is within it's range ; if not reset to the default */
270         if (advwdt_set_heartbeat(timeout)) {
271                 advwdt_set_heartbeat(WATCHDOG_TIMEOUT);
272                 printk (KERN_INFO PFX "timeout value must be 1<=x<=63, using %d\n",
273                         timeout);
274         }
275
276         ret = misc_register(&advwdt_miscdev);
277         if (ret != 0) {
278                 printk (KERN_ERR PFX "cannot register miscdev on minor=%d (err=%d)\n",
279                         WATCHDOG_MINOR, ret);
280                 goto unreg_regions;
281         }
282
283         printk (KERN_INFO PFX "initialized. timeout=%d sec (nowayout=%d)\n",
284                 timeout, nowayout);
285
286 out:
287         return ret;
288 unreg_regions:
289         release_region(wdt_start, 1);
290 unreg_stop:
291         if (wdt_stop != wdt_start)
292                 release_region(wdt_stop, 1);
293         goto out;
294 }
295
296 static int __devexit
297 advwdt_remove(struct platform_device *dev)
298 {
299         misc_deregister(&advwdt_miscdev);
300         release_region(wdt_start,1);
301         if(wdt_stop != wdt_start)
302                 release_region(wdt_stop,1);
303
304         return 0;
305 }
306
307 static void
308 advwdt_shutdown(struct platform_device *dev)
309 {
310         /* Turn the WDT off if we have a soft shutdown */
311         advwdt_disable();
312 }
313
314 static struct platform_driver advwdt_driver = {
315         .probe          = advwdt_probe,
316         .remove         = __devexit_p(advwdt_remove),
317         .shutdown       = advwdt_shutdown,
318         .driver         = {
319                 .owner  = THIS_MODULE,
320                 .name   = DRV_NAME,
321         },
322 };
323
324 static int __init
325 advwdt_init(void)
326 {
327         int err;
328
329         printk(KERN_INFO "WDT driver for Advantech single board computer initialising.\n");
330
331         err = platform_driver_register(&advwdt_driver);
332         if (err)
333                 return err;
334
335         advwdt_platform_device = platform_device_register_simple(DRV_NAME, -1, NULL, 0);
336         if (IS_ERR(advwdt_platform_device)) {
337                 err = PTR_ERR(advwdt_platform_device);
338                 goto unreg_platform_driver;
339         }
340
341         return 0;
342
343 unreg_platform_driver:
344         platform_driver_unregister(&advwdt_driver);
345         return err;
346 }
347
348 static void __exit
349 advwdt_exit(void)
350 {
351         platform_device_unregister(advwdt_platform_device);
352         platform_driver_unregister(&advwdt_driver);
353         printk(KERN_INFO PFX "Watchdog Module Unloaded.\n");
354 }
355
356 module_init(advwdt_init);
357 module_exit(advwdt_exit);
358
359 MODULE_LICENSE("GPL");
360 MODULE_AUTHOR("Marek Michalkiewicz <marekm@linux.org.pl>");
361 MODULE_DESCRIPTION("Advantech Single Board Computer WDT driver");
362 MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR);