watchdog: Use pr_<fmt> and pr_<level>
[sfrench/cifs-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 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
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/platform_device.h>
41 #include <linux/init.h>
42 #include <linux/io.h>
43 #include <linux/uaccess.h>
44
45 #include <asm/system.h>
46
47 #define DRV_NAME "advantechwdt"
48 #define WATCHDOG_NAME "Advantech WDT"
49 #define WATCHDOG_TIMEOUT 60             /* 60 sec default timeout */
50
51 /* the watchdog platform device */
52 static struct platform_device *advwdt_platform_device;
53 static unsigned long advwdt_is_open;
54 static char adv_expect_close;
55
56 /*
57  *      You must set these - there is no sane way to probe for this board.
58  *
59  *      To enable or restart, write the timeout value in seconds (1 to 63)
60  *      to I/O port wdt_start.  To disable, read I/O port wdt_stop.
61  *      Both are 0x443 for most boards (tested on a PCA-6276VE-00B1), but
62  *      check your manual (at least the PCA-6159 seems to be different -
63  *      the manual says wdt_stop is 0x43, not 0x443).
64  *      (0x43 is also a write-only control register for the 8254 timer!)
65  */
66
67 static int wdt_stop = 0x443;
68 module_param(wdt_stop, int, 0);
69 MODULE_PARM_DESC(wdt_stop, "Advantech WDT 'stop' io port (default 0x443)");
70
71 static int wdt_start = 0x443;
72 module_param(wdt_start, int, 0);
73 MODULE_PARM_DESC(wdt_start, "Advantech WDT 'start' io port (default 0x443)");
74
75 static int timeout = WATCHDOG_TIMEOUT;  /* in seconds */
76 module_param(timeout, int, 0);
77 MODULE_PARM_DESC(timeout,
78         "Watchdog timeout in seconds. 1<= timeout <=63, default="
79                 __MODULE_STRING(WATCHDOG_TIMEOUT) ".");
80
81 static int nowayout = WATCHDOG_NOWAYOUT;
82 module_param(nowayout, int, 0);
83 MODULE_PARM_DESC(nowayout,
84         "Watchdog cannot be stopped once started (default="
85                 __MODULE_STRING(WATCHDOG_NOWAYOUT) ")");
86
87 /*
88  *      Watchdog Operations
89  */
90
91 static void advwdt_ping(void)
92 {
93         /* Write a watchdog value */
94         outb_p(timeout, wdt_start);
95 }
96
97 static void advwdt_disable(void)
98 {
99         inb_p(wdt_stop);
100 }
101
102 static int advwdt_set_heartbeat(int t)
103 {
104         if (t < 1 || t > 63)
105                 return -EINVAL;
106         timeout = t;
107         return 0;
108 }
109
110 /*
111  *      /dev/watchdog handling
112  */
113
114 static ssize_t advwdt_write(struct file *file, const char __user *buf,
115                                                 size_t count, loff_t *ppos)
116 {
117         if (count) {
118                 if (!nowayout) {
119                         size_t i;
120
121                         adv_expect_close = 0;
122
123                         for (i = 0; i != count; i++) {
124                                 char c;
125                                 if (get_user(c, buf + i))
126                                         return -EFAULT;
127                                 if (c == 'V')
128                                         adv_expect_close = 42;
129                         }
130                 }
131                 advwdt_ping();
132         }
133         return count;
134 }
135
136 static long advwdt_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
137 {
138         int new_timeout;
139         void __user *argp = (void __user *)arg;
140         int __user *p = argp;
141         static const struct watchdog_info ident = {
142                 .options = WDIOF_KEEPALIVEPING |
143                            WDIOF_SETTIMEOUT |
144                            WDIOF_MAGICCLOSE,
145                 .firmware_version = 1,
146                 .identity = WATCHDOG_NAME,
147         };
148
149         switch (cmd) {
150         case WDIOC_GETSUPPORT:
151                 if (copy_to_user(argp, &ident, sizeof(ident)))
152                         return -EFAULT;
153                 break;
154
155         case WDIOC_GETSTATUS:
156         case WDIOC_GETBOOTSTATUS:
157                 return put_user(0, p);
158
159         case WDIOC_SETOPTIONS:
160         {
161                 int options, retval = -EINVAL;
162
163                 if (get_user(options, p))
164                         return -EFAULT;
165                 if (options & WDIOS_DISABLECARD) {
166                         advwdt_disable();
167                         retval = 0;
168                 }
169                 if (options & WDIOS_ENABLECARD) {
170                         advwdt_ping();
171                         retval = 0;
172                 }
173                 return retval;
174         }
175         case WDIOC_KEEPALIVE:
176                 advwdt_ping();
177                 break;
178
179         case WDIOC_SETTIMEOUT:
180                 if (get_user(new_timeout, p))
181                         return -EFAULT;
182                 if (advwdt_set_heartbeat(new_timeout))
183                         return -EINVAL;
184                 advwdt_ping();
185                 /* Fall */
186         case WDIOC_GETTIMEOUT:
187                 return put_user(timeout, p);
188         default:
189                 return -ENOTTY;
190         }
191         return 0;
192 }
193
194 static int advwdt_open(struct inode *inode, struct file *file)
195 {
196         if (test_and_set_bit(0, &advwdt_is_open))
197                 return -EBUSY;
198         /*
199          *      Activate
200          */
201
202         advwdt_ping();
203         return nonseekable_open(inode, file);
204 }
205
206 static int advwdt_close(struct inode *inode, struct file *file)
207 {
208         if (adv_expect_close == 42) {
209                 advwdt_disable();
210         } else {
211                 pr_crit("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                         pr_err("I/O address 0x%04x already in use\n",
249                                wdt_stop);
250                         ret = -EIO;
251                         goto out;
252                 }
253         }
254
255         if (!request_region(wdt_start, 1, WATCHDOG_NAME)) {
256                 pr_err("I/O address 0x%04x already in use\n", wdt_start);
257                 ret = -EIO;
258                 goto unreg_stop;
259         }
260
261         /* Check that the heartbeat value is within it's range ;
262          * if not reset to the default */
263         if (advwdt_set_heartbeat(timeout)) {
264                 advwdt_set_heartbeat(WATCHDOG_TIMEOUT);
265                 pr_info("timeout value must be 1<=x<=63, using %d\n", timeout);
266         }
267
268         ret = misc_register(&advwdt_miscdev);
269         if (ret != 0) {
270                 pr_err("cannot register miscdev on minor=%d (err=%d)\n",
271                        WATCHDOG_MINOR, ret);
272                 goto unreg_regions;
273         }
274         pr_info("initialized. timeout=%d sec (nowayout=%d)\n",
275                 timeout, nowayout);
276 out:
277         return ret;
278 unreg_regions:
279         release_region(wdt_start, 1);
280 unreg_stop:
281         if (wdt_stop != wdt_start)
282                 release_region(wdt_stop, 1);
283         goto out;
284 }
285
286 static int __devexit advwdt_remove(struct platform_device *dev)
287 {
288         misc_deregister(&advwdt_miscdev);
289         release_region(wdt_start, 1);
290         if (wdt_stop != wdt_start)
291                 release_region(wdt_stop, 1);
292
293         return 0;
294 }
295
296 static void advwdt_shutdown(struct platform_device *dev)
297 {
298         /* Turn the WDT off if we have a soft shutdown */
299         advwdt_disable();
300 }
301
302 static struct platform_driver advwdt_driver = {
303         .probe          = advwdt_probe,
304         .remove         = __devexit_p(advwdt_remove),
305         .shutdown       = advwdt_shutdown,
306         .driver         = {
307                 .owner  = THIS_MODULE,
308                 .name   = DRV_NAME,
309         },
310 };
311
312 static int __init advwdt_init(void)
313 {
314         int err;
315
316         pr_info("WDT driver for Advantech single board computer initialising\n");
317
318         err = platform_driver_register(&advwdt_driver);
319         if (err)
320                 return err;
321
322         advwdt_platform_device = platform_device_register_simple(DRV_NAME,
323                                                                 -1, NULL, 0);
324         if (IS_ERR(advwdt_platform_device)) {
325                 err = PTR_ERR(advwdt_platform_device);
326                 goto unreg_platform_driver;
327         }
328
329         return 0;
330
331 unreg_platform_driver:
332         platform_driver_unregister(&advwdt_driver);
333         return err;
334 }
335
336 static void __exit advwdt_exit(void)
337 {
338         platform_device_unregister(advwdt_platform_device);
339         platform_driver_unregister(&advwdt_driver);
340         pr_info("Watchdog Module Unloaded\n");
341 }
342
343 module_init(advwdt_init);
344 module_exit(advwdt_exit);
345
346 MODULE_LICENSE("GPL");
347 MODULE_AUTHOR("Marek Michalkiewicz <marekm@linux.org.pl>");
348 MODULE_DESCRIPTION("Advantech Single Board Computer WDT driver");
349 MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR);