watchdog: Use pr_<fmt> and pr_<level>
[deliverable/linux.git] / drivers / watchdog / ib700wdt.c
CommitLineData
1da177e4
LT
1/*
2 * IB700 Single Board Computer WDT driver
3 *
4 * (c) Copyright 2001 Charles Howes <chowes@vsol.net>
5 *
c9d7710e
WVS
6 * Based on advantechwdt.c which is based on acquirewdt.c which
7 * is based on wdt.c.
1da177e4
LT
8 *
9 * (c) Copyright 2000-2001 Marek Michalkiewicz <marekm@linux.org.pl>
10 *
11 * Based on acquirewdt.c which is based on wdt.c.
12 * Original copyright messages:
13 *
29fa0586
AC
14 * (c) Copyright 1996 Alan Cox <alan@lxorguk.ukuu.org.uk>,
15 * All Rights Reserved.
1da177e4
LT
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 *
29fa0586 26 * (c) Copyright 1995 Alan Cox <alan@lxorguk.ukuu.org.uk>
1da177e4 27 *
c9d7710e
WVS
28 * 14-Dec-2001 Matt Domsch <Matt_Domsch@dell.com>
29 * Added nowayout module option to override CONFIG_WATCHDOG_NOWAYOUT
30 * Added timeout module option to override default
1da177e4
LT
31 *
32 */
33
27c766aa
JP
34#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
35
1da177e4
LT
36#include <linux/module.h>
37#include <linux/types.h>
38#include <linux/miscdevice.h>
39#include <linux/watchdog.h>
40#include <linux/ioport.h>
1da177e4 41#include <linux/fs.h>
1da177e4
LT
42#include <linux/init.h>
43#include <linux/spinlock.h>
44#include <linux/moduleparam.h>
745ac1ea 45#include <linux/platform_device.h>
2e43ba73
AC
46#include <linux/io.h>
47#include <linux/uaccess.h>
089ab079 48
1da177e4
LT
49#include <asm/system.h>
50
745ac1ea 51static struct platform_device *ibwdt_platform_device;
1da177e4 52static unsigned long ibwdt_is_open;
c7dfd0cc 53static DEFINE_SPINLOCK(ibwdt_lock);
1da177e4
LT
54static char expect_close;
55
745ac1ea
WVS
56/* Module information */
57#define DRV_NAME "ib700wdt"
1da177e4
LT
58
59/*
60 *
61 * Watchdog Timer Configuration
62 *
63 * The function of the watchdog timer is to reset the system
64 * automatically and is defined at I/O port 0443H. To enable the
65 * watchdog timer and allow the system to reset, write I/O port 0443H.
66 * To disable the timer, write I/O port 0441H for the system to stop the
67 * watchdog function. The timer has a tolerance of 20% for its
68 * intervals.
69 *
70 * The following describes how the timer should be programmed.
71 *
72 * Enabling Watchdog:
73 * MOV AX,000FH (Choose the values from 0 to F)
74 * MOV DX,0443H
75 * OUT DX,AX
76 *
77 * Disabling Watchdog:
78 * MOV AX,000FH (Any value is fine.)
79 * MOV DX,0441H
80 * OUT DX,AX
81 *
82 * Watchdog timer control table:
83 * Level Value Time/sec | Level Value Time/sec
84 * 1 F 0 | 9 7 16
85 * 2 E 2 | 10 6 18
86 * 3 D 4 | 11 5 20
87 * 4 C 6 | 12 4 22
88 * 5 B 8 | 13 3 24
89 * 6 A 10 | 14 2 26
90 * 7 9 12 | 15 1 28
91 * 8 8 14 | 16 0 30
92 *
93 */
94
1da177e4
LT
95#define WDT_STOP 0x441
96#define WDT_START 0x443
97
98/* Default timeout */
794db26f
WVS
99#define WATCHDOG_TIMEOUT 30 /* 30 seconds +/- 20% */
100static int timeout = WATCHDOG_TIMEOUT; /* in seconds */
101module_param(timeout, int, 0);
102MODULE_PARM_DESC(timeout,
103 "Watchdog timeout in seconds. 0<= timeout <=30, default="
104 __MODULE_STRING(WATCHDOG_TIMEOUT) ".");
1da177e4 105
4bfdf378 106static int nowayout = WATCHDOG_NOWAYOUT;
1da177e4 107module_param(nowayout, int, 0);
2e43ba73
AC
108MODULE_PARM_DESC(nowayout,
109 "Watchdog cannot be stopped once started (default="
110 __MODULE_STRING(WATCHDOG_NOWAYOUT) ")");
1da177e4
LT
111
112
113/*
35d55c94 114 * Watchdog Operations
1da177e4
LT
115 */
116
7944d3a5 117static void ibwdt_ping(void)
1da177e4 118{
794db26f
WVS
119 int wd_margin = 15 - ((timeout + 1) / 2);
120
e42162a4
WVS
121 spin_lock(&ibwdt_lock);
122
1da177e4
LT
123 /* Write a watchdog value */
124 outb_p(wd_margin, WDT_START);
e42162a4
WVS
125
126 spin_unlock(&ibwdt_lock);
1da177e4
LT
127}
128
7944d3a5 129static void ibwdt_disable(void)
35d55c94 130{
e42162a4 131 spin_lock(&ibwdt_lock);
35d55c94 132 outb_p(0, WDT_STOP);
e42162a4 133 spin_unlock(&ibwdt_lock);
35d55c94
WVS
134}
135
7944d3a5 136static int ibwdt_set_heartbeat(int t)
35d55c94 137{
794db26f 138 if (t < 0 || t > 30)
35d55c94
WVS
139 return -EINVAL;
140
794db26f 141 timeout = t;
35d55c94
WVS
142 return 0;
143}
144
145/*
146 * /dev/watchdog handling
147 */
148
2e43ba73
AC
149static ssize_t ibwdt_write(struct file *file, const char __user *buf,
150 size_t count, loff_t *ppos)
1da177e4
LT
151{
152 if (count) {
153 if (!nowayout) {
154 size_t i;
155
156 /* In case it was set long ago */
157 expect_close = 0;
158
159 for (i = 0; i != count; i++) {
160 char c;
161 if (get_user(c, buf + i))
162 return -EFAULT;
163 if (c == 'V')
164 expect_close = 42;
165 }
166 }
167 ibwdt_ping();
168 }
169 return count;
170}
171
2e43ba73 172static long ibwdt_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
1da177e4 173{
35d55c94 174 int new_margin;
1da177e4
LT
175 void __user *argp = (void __user *)arg;
176 int __user *p = argp;
177
42747d71 178 static const struct watchdog_info ident = {
2e43ba73
AC
179 .options = WDIOF_KEEPALIVEPING | WDIOF_SETTIMEOUT
180 | WDIOF_MAGICCLOSE,
1da177e4
LT
181 .firmware_version = 1,
182 .identity = "IB700 WDT",
183 };
184
185 switch (cmd) {
186 case WDIOC_GETSUPPORT:
2e43ba73
AC
187 if (copy_to_user(argp, &ident, sizeof(ident)))
188 return -EFAULT;
189 break;
1da177e4
LT
190
191 case WDIOC_GETSTATUS:
c9d7710e 192 case WDIOC_GETBOOTSTATUS:
2e43ba73 193 return put_user(0, p);
1da177e4 194
e42162a4
WVS
195 case WDIOC_SETOPTIONS:
196 {
2e43ba73 197 int options, retval = -EINVAL;
e42162a4 198
2e43ba73
AC
199 if (get_user(options, p))
200 return -EFAULT;
e42162a4 201
2e43ba73
AC
202 if (options & WDIOS_DISABLECARD) {
203 ibwdt_disable();
204 retval = 0;
205 }
206 if (options & WDIOS_ENABLECARD) {
207 ibwdt_ping();
208 retval = 0;
209 }
210 return retval;
e42162a4 211 }
0c06090c
WVS
212 case WDIOC_KEEPALIVE:
213 ibwdt_ping();
214 break;
215
216 case WDIOC_SETTIMEOUT:
217 if (get_user(new_margin, p))
218 return -EFAULT;
219 if (ibwdt_set_heartbeat(new_margin))
220 return -EINVAL;
221 ibwdt_ping();
222 /* Fall */
223
224 case WDIOC_GETTIMEOUT:
794db26f 225 return put_user(timeout, p);
0c06090c 226
1da177e4 227 default:
2e43ba73 228 return -ENOTTY;
1da177e4
LT
229 }
230 return 0;
231}
232
2e43ba73 233static int ibwdt_open(struct inode *inode, struct file *file)
1da177e4 234{
2e43ba73 235 if (test_and_set_bit(0, &ibwdt_is_open))
1da177e4 236 return -EBUSY;
1da177e4
LT
237 if (nowayout)
238 __module_get(THIS_MODULE);
239
240 /* Activate */
241 ibwdt_ping();
1da177e4
LT
242 return nonseekable_open(inode, file);
243}
244
7944d3a5 245static int ibwdt_close(struct inode *inode, struct file *file)
1da177e4 246{
c9d7710e 247 if (expect_close == 42) {
35d55c94 248 ibwdt_disable();
c9d7710e 249 } else {
27c766aa 250 pr_crit("WDT device closed unexpectedly. WDT will not stop!\n");
c9d7710e
WVS
251 ibwdt_ping();
252 }
1da177e4
LT
253 clear_bit(0, &ibwdt_is_open);
254 expect_close = 0;
1da177e4
LT
255 return 0;
256}
257
1da177e4
LT
258/*
259 * Kernel Interfaces
260 */
261
62322d25 262static const struct file_operations ibwdt_fops = {
1da177e4
LT
263 .owner = THIS_MODULE,
264 .llseek = no_llseek,
265 .write = ibwdt_write,
2e43ba73 266 .unlocked_ioctl = ibwdt_ioctl,
1da177e4
LT
267 .open = ibwdt_open,
268 .release = ibwdt_close,
269};
270
271static struct miscdevice ibwdt_miscdev = {
272 .minor = WATCHDOG_MINOR,
273 .name = "watchdog",
274 .fops = &ibwdt_fops,
275};
276
f6e48039
WVS
277/*
278 * Init & exit routines
279 */
280
745ac1ea 281static int __devinit ibwdt_probe(struct platform_device *dev)
1da177e4
LT
282{
283 int res;
284
1da177e4
LT
285#if WDT_START != WDT_STOP
286 if (!request_region(WDT_STOP, 1, "IB700 WDT")) {
27c766aa 287 pr_err("STOP method I/O %X is not available\n", WDT_STOP);
1da177e4
LT
288 res = -EIO;
289 goto out_nostopreg;
290 }
291#endif
292
293 if (!request_region(WDT_START, 1, "IB700 WDT")) {
27c766aa 294 pr_err("START method I/O %X is not available\n", WDT_START);
1da177e4
LT
295 res = -EIO;
296 goto out_nostartreg;
297 }
f6e48039 298
794db26f
WVS
299 /* Check that the heartbeat value is within it's range ;
300 * if not reset to the default */
301 if (ibwdt_set_heartbeat(timeout)) {
302 ibwdt_set_heartbeat(WATCHDOG_TIMEOUT);
27c766aa 303 pr_info("timeout value must be 0<=x<=30, using %d\n", timeout);
794db26f
WVS
304 }
305
f6e48039
WVS
306 res = misc_register(&ibwdt_miscdev);
307 if (res) {
27c766aa 308 pr_err("failed to register misc device\n");
f6e48039
WVS
309 goto out_nomisc;
310 }
1da177e4
LT
311 return 0;
312
f6e48039 313out_nomisc:
1da177e4
LT
314 release_region(WDT_START, 1);
315out_nostartreg:
316#if WDT_START != WDT_STOP
317 release_region(WDT_STOP, 1);
318#endif
319out_nostopreg:
1da177e4
LT
320 return res;
321}
322
745ac1ea 323static int __devexit ibwdt_remove(struct platform_device *dev)
1da177e4
LT
324{
325 misc_deregister(&ibwdt_miscdev);
2e43ba73 326 release_region(WDT_START, 1);
1da177e4 327#if WDT_START != WDT_STOP
2e43ba73 328 release_region(WDT_STOP, 1);
1da177e4 329#endif
745ac1ea
WVS
330 return 0;
331}
332
35fcf538
WVS
333static void ibwdt_shutdown(struct platform_device *dev)
334{
335 /* Turn the WDT off if we have a soft shutdown */
336 ibwdt_disable();
337}
338
745ac1ea
WVS
339static struct platform_driver ibwdt_driver = {
340 .probe = ibwdt_probe,
341 .remove = __devexit_p(ibwdt_remove),
35fcf538 342 .shutdown = ibwdt_shutdown,
745ac1ea
WVS
343 .driver = {
344 .owner = THIS_MODULE,
345 .name = DRV_NAME,
346 },
347};
348
349static int __init ibwdt_init(void)
350{
351 int err;
352
27c766aa 353 pr_info("WDT driver for IB700 single board computer initialising\n");
745ac1ea
WVS
354
355 err = platform_driver_register(&ibwdt_driver);
356 if (err)
357 return err;
358
2e43ba73
AC
359 ibwdt_platform_device = platform_device_register_simple(DRV_NAME,
360 -1, NULL, 0);
745ac1ea
WVS
361 if (IS_ERR(ibwdt_platform_device)) {
362 err = PTR_ERR(ibwdt_platform_device);
363 goto unreg_platform_driver;
364 }
365
366 return 0;
367
368unreg_platform_driver:
369 platform_driver_unregister(&ibwdt_driver);
370 return err;
371}
372
373static void __exit ibwdt_exit(void)
374{
375 platform_device_unregister(ibwdt_platform_device);
376 platform_driver_unregister(&ibwdt_driver);
27c766aa 377 pr_info("Watchdog Module Unloaded\n");
1da177e4
LT
378}
379
380module_init(ibwdt_init);
381module_exit(ibwdt_exit);
382
383MODULE_AUTHOR("Charles Howes <chowes@vsol.net>");
384MODULE_DESCRIPTION("IB700 SBC watchdog driver");
385MODULE_LICENSE("GPL");
386MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR);
387
388/* end of ib700wdt.c */
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