parport_pc: show the detection of a 2 serial port ITE8874 chip
[linux-2.6.git] / 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@lxorguk.ukuu.org.uk>,
10  *                                              All Rights Reserved.
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@lxorguk.ukuu.org.uk>
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 #include <linux/io.h>
41 #include <linux/uaccess.h>
42
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 /* the watchdog platform device */
51 static struct platform_device *advwdt_platform_device;
52 static unsigned long advwdt_is_open;
53 static char adv_expect_close;
54
55 /*
56  *      You must set these - there is no sane way to probe for this board.
57  *
58  *      To enable or restart, write the timeout value in seconds (1 to 63)
59  *      to I/O port wdt_start.  To disable, read I/O port wdt_stop.
60  *      Both are 0x443 for most boards (tested on a PCA-6276VE-00B1), but
61  *      check your manual (at least the PCA-6159 seems to be different -
62  *      the manual says wdt_stop is 0x43, not 0x443).
63  *      (0x43 is also a write-only control register for the 8254 timer!)
64  */
65
66 static int wdt_stop = 0x443;
67 module_param(wdt_stop, int, 0);
68 MODULE_PARM_DESC(wdt_stop, "Advantech WDT 'stop' io port (default 0x443)");
69
70 static int wdt_start = 0x443;
71 module_param(wdt_start, int, 0);
72 MODULE_PARM_DESC(wdt_start, "Advantech WDT 'start' io port (default 0x443)");
73
74 static int timeout = WATCHDOG_TIMEOUT;  /* in seconds */
75 module_param(timeout, int, 0);
76 MODULE_PARM_DESC(timeout,
77         "Watchdog timeout in seconds. 1<= timeout <=63, default="
78                 __MODULE_STRING(WATCHDOG_TIMEOUT) ".");
79
80 static int nowayout = WATCHDOG_NOWAYOUT;
81 module_param(nowayout, int, 0);
82 MODULE_PARM_DESC(nowayout,
83         "Watchdog cannot be stopped once started (default="
84                 __MODULE_STRING(WATCHDOG_NOWAYOUT) ")");
85
86 /*
87  *      Watchdog Operations
88  */
89
90 static void advwdt_ping(void)
91 {
92         /* Write a watchdog value */
93         outb_p(timeout, wdt_start);
94 }
95
96 static void advwdt_disable(void)
97 {
98         inb_p(wdt_stop);
99 }
100
101 static int advwdt_set_heartbeat(int t)
102 {
103         if (t < 1 || t > 63)
104                 return -EINVAL;
105         timeout = t;
106         return 0;
107 }
108
109 /*
110  *      /dev/watchdog handling
111  */
112
113 static ssize_t advwdt_write(struct file *file, const char __user *buf,
114                                                 size_t count, loff_t *ppos)
115 {
116         if (count) {
117                 if (!nowayout) {
118                         size_t i;
119
120                         adv_expect_close = 0;
121
122                         for (i = 0; i != count; i++) {
123                                 char c;
124                                 if (get_user(c, buf + i))
125                                         return -EFAULT;
126                                 if (c == 'V')
127                                         adv_expect_close = 42;
128                         }
129                 }
130                 advwdt_ping();
131         }
132         return count;
133 }
134
135 static long advwdt_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
136 {
137         int new_timeout;
138         void __user *argp = (void __user *)arg;
139         int __user *p = argp;
140         static const struct watchdog_info ident = {
141                 .options = WDIOF_KEEPALIVEPING |
142                            WDIOF_SETTIMEOUT |
143                            WDIOF_MAGICCLOSE,
144                 .firmware_version = 1,
145                 .identity = WATCHDOG_NAME,
146         };
147
148         switch (cmd) {
149         case WDIOC_GETSUPPORT:
150                 if (copy_to_user(argp, &ident, sizeof(ident)))
151                         return -EFAULT;
152                 break;
153
154         case WDIOC_GETSTATUS:
155         case WDIOC_GETBOOTSTATUS:
156                 return put_user(0, p);
157
158         case WDIOC_SETOPTIONS:
159         {
160                 int options, retval = -EINVAL;
161
162                 if (get_user(options, p))
163                         return -EFAULT;
164                 if (options & WDIOS_DISABLECARD) {
165                         advwdt_disable();
166                         retval = 0;
167                 }
168                 if (options & WDIOS_ENABLECARD) {
169                         advwdt_ping();
170                         retval = 0;
171                 }
172                 return retval;
173         }
174         case WDIOC_KEEPALIVE:
175                 advwdt_ping();
176                 break;
177
178         case WDIOC_SETTIMEOUT:
179                 if (get_user(new_timeout, p))
180                         return -EFAULT;
181                 if (advwdt_set_heartbeat(new_timeout))
182                         return -EINVAL;
183                 advwdt_ping();
184                 /* Fall */
185         case WDIOC_GETTIMEOUT:
186                 return put_user(timeout, p);
187         default:
188                 return -ENOTTY;
189         }
190         return 0;
191 }
192
193 static int advwdt_open(struct inode *inode, struct file *file)
194 {
195         if (test_and_set_bit(0, &advwdt_is_open))
196                 return -EBUSY;
197         /*
198          *      Activate
199          */
200
201         advwdt_ping();
202         return nonseekable_open(inode, file);
203 }
204
205 static int advwdt_close(struct inode *inode, struct file *file)
206 {
207         if (adv_expect_close == 42) {
208                 advwdt_disable();
209         } else {
210                 printk(KERN_CRIT PFX
211                                 "Unexpected close, not stopping watchdog!\n");
212                 advwdt_ping();
213         }
214         clear_bit(0, &advwdt_is_open);
215         adv_expect_close = 0;
216         return 0;
217 }
218
219 /*
220  *      Kernel Interfaces
221  */
222
223 static const struct file_operations advwdt_fops = {
224         .owner          = THIS_MODULE,
225         .llseek         = no_llseek,
226         .write          = advwdt_write,
227         .unlocked_ioctl = advwdt_ioctl,
228         .open           = advwdt_open,
229         .release        = advwdt_close,
230 };
231
232 static struct miscdevice advwdt_miscdev = {
233         .minor  = WATCHDOG_MINOR,
234         .name   = "watchdog",
235         .fops   = &advwdt_fops,
236 };
237
238 /*
239  *      Init & exit routines
240  */
241
242 static int __devinit advwdt_probe(struct platform_device *dev)
243 {
244         int ret;
245
246         if (wdt_stop != wdt_start) {
247                 if (!request_region(wdt_stop, 1, WATCHDOG_NAME)) {
248                         printk(KERN_ERR PFX
249                                 "I/O address 0x%04x already in use\n",
250                                                                 wdt_stop);
251                         ret = -EIO;
252                         goto out;
253                 }
254         }
255
256         if (!request_region(wdt_start, 1, WATCHDOG_NAME)) {
257                 printk(KERN_ERR PFX
258                                 "I/O address 0x%04x already in use\n",
259                                                                 wdt_start);
260                 ret = -EIO;
261                 goto unreg_stop;
262         }
263
264         /* Check that the heartbeat value is within it's range ;
265          * if not reset to the default */
266         if (advwdt_set_heartbeat(timeout)) {
267                 advwdt_set_heartbeat(WATCHDOG_TIMEOUT);
268                 printk(KERN_INFO PFX
269                         "timeout value must be 1<=x<=63, using %d\n", timeout);
270         }
271
272         ret = misc_register(&advwdt_miscdev);
273         if (ret != 0) {
274                 printk(KERN_ERR PFX
275                         "cannot register miscdev on minor=%d (err=%d)\n",
276                                                         WATCHDOG_MINOR, ret);
277                 goto unreg_regions;
278         }
279         printk(KERN_INFO PFX "initialized. timeout=%d sec (nowayout=%d)\n",
280                 timeout, nowayout);
281 out:
282         return ret;
283 unreg_regions:
284         release_region(wdt_start, 1);
285 unreg_stop:
286         if (wdt_stop != wdt_start)
287                 release_region(wdt_stop, 1);
288         goto out;
289 }
290
291 static int __devexit advwdt_remove(struct platform_device *dev)
292 {
293         misc_deregister(&advwdt_miscdev);
294         release_region(wdt_start, 1);
295         if (wdt_stop != wdt_start)
296                 release_region(wdt_stop, 1);
297
298         return 0;
299 }
300
301 static void advwdt_shutdown(struct platform_device *dev)
302 {
303         /* Turn the WDT off if we have a soft shutdown */
304         advwdt_disable();
305 }
306
307 static struct platform_driver advwdt_driver = {
308         .probe          = advwdt_probe,
309         .remove         = __devexit_p(advwdt_remove),
310         .shutdown       = advwdt_shutdown,
311         .driver         = {
312                 .owner  = THIS_MODULE,
313                 .name   = DRV_NAME,
314         },
315 };
316
317 static int __init advwdt_init(void)
318 {
319         int err;
320
321         printk(KERN_INFO
322              "WDT driver for Advantech single board computer initialising.\n");
323
324         err = platform_driver_register(&advwdt_driver);
325         if (err)
326                 return err;
327
328         advwdt_platform_device = platform_device_register_simple(DRV_NAME,
329                                                                 -1, NULL, 0);
330         if (IS_ERR(advwdt_platform_device)) {
331                 err = PTR_ERR(advwdt_platform_device);
332                 goto unreg_platform_driver;
333         }
334
335         return 0;
336
337 unreg_platform_driver:
338         platform_driver_unregister(&advwdt_driver);
339         return err;
340 }
341
342 static void __exit advwdt_exit(void)
343 {
344         platform_device_unregister(advwdt_platform_device);
345         platform_driver_unregister(&advwdt_driver);
346         printk(KERN_INFO PFX "Watchdog Module Unloaded.\n");
347 }
348
349 module_init(advwdt_init);
350 module_exit(advwdt_exit);
351
352 MODULE_LICENSE("GPL");
353 MODULE_AUTHOR("Marek Michalkiewicz <marekm@linux.org.pl>");
354 MODULE_DESCRIPTION("Advantech Single Board Computer WDT driver");
355 MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR);