blob: 05a28106e8eb7f8fdef5dfb35f0b61d6cd34226e [file] [log] [blame]
Linus Torvalds1da177e2005-04-16 15:20:36 -07001/*
2 * IB700 Single Board Computer WDT driver
3 *
4 * (c) Copyright 2001 Charles Howes <chowes@vsol.net>
5 *
Wim Van Sebroeckc9d77102007-01-27 22:07:03 +01006 * Based on advantechwdt.c which is based on acquirewdt.c which
7 * is based on wdt.c.
Linus Torvalds1da177e2005-04-16 15:20:36 -07008 *
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 *
14 * (c) Copyright 1996 Alan Cox <alan@redhat.com>, All Rights Reserved.
15 * http://www.redhat.com
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 *
26 * (c) Copyright 1995 Alan Cox <alan@redhat.com>
27 *
Wim Van Sebroeckc9d77102007-01-27 22:07:03 +010028 * 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
Linus Torvalds1da177e2005-04-16 15:20:36 -070031 *
32 */
33
Linus Torvalds1da177e2005-04-16 15:20:36 -070034#include <linux/module.h>
35#include <linux/types.h>
36#include <linux/miscdevice.h>
37#include <linux/watchdog.h>
38#include <linux/ioport.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070039#include <linux/fs.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070040#include <linux/init.h>
41#include <linux/spinlock.h>
42#include <linux/moduleparam.h>
Wim Van Sebroeck745ac1ea2007-01-27 22:39:46 +010043#include <linux/platform_device.h>
Alan Cox2e43ba72008-05-19 14:05:52 +010044#include <linux/io.h>
45#include <linux/uaccess.h>
Wim Van Sebroeck089ab072008-07-15 11:46:11 +000046
Linus Torvalds1da177e2005-04-16 15:20:36 -070047#include <asm/system.h>
48
Wim Van Sebroeck745ac1ea2007-01-27 22:39:46 +010049static struct platform_device *ibwdt_platform_device;
Linus Torvalds1da177e2005-04-16 15:20:36 -070050static unsigned long ibwdt_is_open;
Alexey Dobriyanc7dfd0c2007-11-01 16:27:08 -070051static DEFINE_SPINLOCK(ibwdt_lock);
Linus Torvalds1da177e2005-04-16 15:20:36 -070052static char expect_close;
53
Wim Van Sebroeck745ac1ea2007-01-27 22:39:46 +010054/* Module information */
55#define DRV_NAME "ib700wdt"
56#define PFX DRV_NAME ": "
Linus Torvalds1da177e2005-04-16 15:20:36 -070057
58/*
59 *
60 * Watchdog Timer Configuration
61 *
62 * The function of the watchdog timer is to reset the system
63 * automatically and is defined at I/O port 0443H. To enable the
64 * watchdog timer and allow the system to reset, write I/O port 0443H.
65 * To disable the timer, write I/O port 0441H for the system to stop the
66 * watchdog function. The timer has a tolerance of 20% for its
67 * intervals.
68 *
69 * The following describes how the timer should be programmed.
70 *
71 * Enabling Watchdog:
72 * MOV AX,000FH (Choose the values from 0 to F)
73 * MOV DX,0443H
74 * OUT DX,AX
75 *
76 * Disabling Watchdog:
77 * MOV AX,000FH (Any value is fine.)
78 * MOV DX,0441H
79 * OUT DX,AX
80 *
81 * Watchdog timer control table:
82 * Level Value Time/sec | Level Value Time/sec
83 * 1 F 0 | 9 7 16
84 * 2 E 2 | 10 6 18
85 * 3 D 4 | 11 5 20
86 * 4 C 6 | 12 4 22
87 * 5 B 8 | 13 3 24
88 * 6 A 10 | 14 2 26
89 * 7 9 12 | 15 1 28
90 * 8 8 14 | 16 0 30
91 *
92 */
93
94static int wd_times[] = {
95 30, /* 0x0 */
96 28, /* 0x1 */
97 26, /* 0x2 */
98 24, /* 0x3 */
99 22, /* 0x4 */
100 20, /* 0x5 */
101 18, /* 0x6 */
102 16, /* 0x7 */
103 14, /* 0x8 */
104 12, /* 0x9 */
105 10, /* 0xA */
106 8, /* 0xB */
107 6, /* 0xC */
108 4, /* 0xD */
109 2, /* 0xE */
110 0, /* 0xF */
111};
112
113#define WDT_STOP 0x441
114#define WDT_START 0x443
115
116/* Default timeout */
117#define WD_TIMO 0 /* 30 seconds +/- 20%, from table */
118
119static int wd_margin = WD_TIMO;
120
Andrey Panin4bfdf372005-07-27 11:43:58 -0700121static int nowayout = WATCHDOG_NOWAYOUT;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700122module_param(nowayout, int, 0);
Alan Cox2e43ba72008-05-19 14:05:52 +0100123MODULE_PARM_DESC(nowayout,
124 "Watchdog cannot be stopped once started (default="
125 __MODULE_STRING(WATCHDOG_NOWAYOUT) ")");
Linus Torvalds1da177e2005-04-16 15:20:36 -0700126
127
128/*
Wim Van Sebroeck35d55c92007-01-27 21:50:53 +0100129 * Watchdog Operations
Linus Torvalds1da177e2005-04-16 15:20:36 -0700130 */
131
Wim Van Sebroeck7944d3a2008-08-06 20:19:41 +0000132static void ibwdt_ping(void)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700133{
Wim Van Sebroecke42162a2007-01-27 22:12:54 +0100134 spin_lock(&ibwdt_lock);
135
Linus Torvalds1da177e2005-04-16 15:20:36 -0700136 /* Write a watchdog value */
137 outb_p(wd_margin, WDT_START);
Wim Van Sebroecke42162a2007-01-27 22:12:54 +0100138
139 spin_unlock(&ibwdt_lock);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700140}
141
Wim Van Sebroeck7944d3a2008-08-06 20:19:41 +0000142static void ibwdt_disable(void)
Wim Van Sebroeck35d55c92007-01-27 21:50:53 +0100143{
Wim Van Sebroecke42162a2007-01-27 22:12:54 +0100144 spin_lock(&ibwdt_lock);
Wim Van Sebroeck35d55c92007-01-27 21:50:53 +0100145 outb_p(0, WDT_STOP);
Wim Van Sebroecke42162a2007-01-27 22:12:54 +0100146 spin_unlock(&ibwdt_lock);
Wim Van Sebroeck35d55c92007-01-27 21:50:53 +0100147}
148
Wim Van Sebroeck7944d3a2008-08-06 20:19:41 +0000149static int ibwdt_set_heartbeat(int t)
Wim Van Sebroeck35d55c92007-01-27 21:50:53 +0100150{
151 int i;
152
153 if ((t < 0) || (t > 30))
154 return -EINVAL;
155
156 for (i = 0x0F; i > -1; i--)
157 if (wd_times[i] > t)
158 break;
159 wd_margin = i;
160 return 0;
161}
162
163/*
164 * /dev/watchdog handling
165 */
166
Alan Cox2e43ba72008-05-19 14:05:52 +0100167static ssize_t ibwdt_write(struct file *file, const char __user *buf,
168 size_t count, loff_t *ppos)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700169{
170 if (count) {
171 if (!nowayout) {
172 size_t i;
173
174 /* In case it was set long ago */
175 expect_close = 0;
176
177 for (i = 0; i != count; i++) {
178 char c;
179 if (get_user(c, buf + i))
180 return -EFAULT;
181 if (c == 'V')
182 expect_close = 42;
183 }
184 }
185 ibwdt_ping();
186 }
187 return count;
188}
189
Alan Cox2e43ba72008-05-19 14:05:52 +0100190static long ibwdt_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700191{
Wim Van Sebroeck35d55c92007-01-27 21:50:53 +0100192 int new_margin;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700193 void __user *argp = (void __user *)arg;
194 int __user *p = argp;
195
196 static struct watchdog_info ident = {
Alan Cox2e43ba72008-05-19 14:05:52 +0100197 .options = WDIOF_KEEPALIVEPING | WDIOF_SETTIMEOUT
198 | WDIOF_MAGICCLOSE,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700199 .firmware_version = 1,
200 .identity = "IB700 WDT",
201 };
202
203 switch (cmd) {
204 case WDIOC_GETSUPPORT:
Alan Cox2e43ba72008-05-19 14:05:52 +0100205 if (copy_to_user(argp, &ident, sizeof(ident)))
206 return -EFAULT;
207 break;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700208
209 case WDIOC_GETSTATUS:
Wim Van Sebroeckc9d77102007-01-27 22:07:03 +0100210 case WDIOC_GETBOOTSTATUS:
Alan Cox2e43ba72008-05-19 14:05:52 +0100211 return put_user(0, p);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700212
Wim Van Sebroecke42162a2007-01-27 22:12:54 +0100213 case WDIOC_SETOPTIONS:
214 {
Alan Cox2e43ba72008-05-19 14:05:52 +0100215 int options, retval = -EINVAL;
Wim Van Sebroecke42162a2007-01-27 22:12:54 +0100216
Alan Cox2e43ba72008-05-19 14:05:52 +0100217 if (get_user(options, p))
218 return -EFAULT;
Wim Van Sebroecke42162a2007-01-27 22:12:54 +0100219
Alan Cox2e43ba72008-05-19 14:05:52 +0100220 if (options & WDIOS_DISABLECARD) {
221 ibwdt_disable();
222 retval = 0;
223 }
224 if (options & WDIOS_ENABLECARD) {
225 ibwdt_ping();
226 retval = 0;
227 }
228 return retval;
Wim Van Sebroecke42162a2007-01-27 22:12:54 +0100229 }
Wim Van Sebroeck0c060902008-07-18 11:41:17 +0000230 case WDIOC_KEEPALIVE:
231 ibwdt_ping();
232 break;
233
234 case WDIOC_SETTIMEOUT:
235 if (get_user(new_margin, p))
236 return -EFAULT;
237 if (ibwdt_set_heartbeat(new_margin))
238 return -EINVAL;
239 ibwdt_ping();
240 /* Fall */
241
242 case WDIOC_GETTIMEOUT:
243 return put_user(wd_times[wd_margin], p);
244
Linus Torvalds1da177e2005-04-16 15:20:36 -0700245 default:
Alan Cox2e43ba72008-05-19 14:05:52 +0100246 return -ENOTTY;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700247 }
248 return 0;
249}
250
Alan Cox2e43ba72008-05-19 14:05:52 +0100251static int ibwdt_open(struct inode *inode, struct file *file)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700252{
Alan Cox2e43ba72008-05-19 14:05:52 +0100253 if (test_and_set_bit(0, &ibwdt_is_open))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700254 return -EBUSY;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700255 if (nowayout)
256 __module_get(THIS_MODULE);
257
258 /* Activate */
259 ibwdt_ping();
Linus Torvalds1da177e2005-04-16 15:20:36 -0700260 return nonseekable_open(inode, file);
261}
262
Wim Van Sebroeck7944d3a2008-08-06 20:19:41 +0000263static int ibwdt_close(struct inode *inode, struct file *file)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700264{
Wim Van Sebroeckc9d77102007-01-27 22:07:03 +0100265 if (expect_close == 42) {
Wim Van Sebroeck35d55c92007-01-27 21:50:53 +0100266 ibwdt_disable();
Wim Van Sebroeckc9d77102007-01-27 22:07:03 +0100267 } else {
Alan Cox2e43ba72008-05-19 14:05:52 +0100268 printk(KERN_CRIT PFX
269 "WDT device closed unexpectedly. WDT will not stop!\n");
Wim Van Sebroeckc9d77102007-01-27 22:07:03 +0100270 ibwdt_ping();
271 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700272 clear_bit(0, &ibwdt_is_open);
273 expect_close = 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700274 return 0;
275}
276
277/*
Linus Torvalds1da177e2005-04-16 15:20:36 -0700278 * Kernel Interfaces
279 */
280
Arjan van de Ven62322d22006-07-03 00:24:21 -0700281static const struct file_operations ibwdt_fops = {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700282 .owner = THIS_MODULE,
283 .llseek = no_llseek,
284 .write = ibwdt_write,
Alan Cox2e43ba72008-05-19 14:05:52 +0100285 .unlocked_ioctl = ibwdt_ioctl,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700286 .open = ibwdt_open,
287 .release = ibwdt_close,
288};
289
290static struct miscdevice ibwdt_miscdev = {
291 .minor = WATCHDOG_MINOR,
292 .name = "watchdog",
293 .fops = &ibwdt_fops,
294};
295
296/*
Wim Van Sebroeckf6e48032007-01-27 21:58:08 +0100297 * Init & exit routines
298 */
299
Wim Van Sebroeck745ac1ea2007-01-27 22:39:46 +0100300static int __devinit ibwdt_probe(struct platform_device *dev)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700301{
302 int res;
303
Linus Torvalds1da177e2005-04-16 15:20:36 -0700304#if WDT_START != WDT_STOP
305 if (!request_region(WDT_STOP, 1, "IB700 WDT")) {
Alan Cox2e43ba72008-05-19 14:05:52 +0100306 printk(KERN_ERR PFX "STOP method I/O %X is not available.\n",
307 WDT_STOP);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700308 res = -EIO;
309 goto out_nostopreg;
310 }
311#endif
312
313 if (!request_region(WDT_START, 1, "IB700 WDT")) {
Alan Cox2e43ba72008-05-19 14:05:52 +0100314 printk(KERN_ERR PFX "START method I/O %X is not available.\n",
315 WDT_START);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700316 res = -EIO;
317 goto out_nostartreg;
318 }
Wim Van Sebroeckf6e48032007-01-27 21:58:08 +0100319
Wim Van Sebroeckf6e48032007-01-27 21:58:08 +0100320 res = misc_register(&ibwdt_miscdev);
321 if (res) {
Alan Cox2e43ba72008-05-19 14:05:52 +0100322 printk(KERN_ERR PFX "failed to register misc device\n");
Wim Van Sebroeckf6e48032007-01-27 21:58:08 +0100323 goto out_nomisc;
324 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700325 return 0;
326
Wim Van Sebroeckf6e48032007-01-27 21:58:08 +0100327out_nomisc:
Linus Torvalds1da177e2005-04-16 15:20:36 -0700328 release_region(WDT_START, 1);
329out_nostartreg:
330#if WDT_START != WDT_STOP
331 release_region(WDT_STOP, 1);
332#endif
333out_nostopreg:
Linus Torvalds1da177e2005-04-16 15:20:36 -0700334 return res;
335}
336
Wim Van Sebroeck745ac1ea2007-01-27 22:39:46 +0100337static int __devexit ibwdt_remove(struct platform_device *dev)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700338{
339 misc_deregister(&ibwdt_miscdev);
Alan Cox2e43ba72008-05-19 14:05:52 +0100340 release_region(WDT_START, 1);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700341#if WDT_START != WDT_STOP
Alan Cox2e43ba72008-05-19 14:05:52 +0100342 release_region(WDT_STOP, 1);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700343#endif
Wim Van Sebroeck745ac1ea2007-01-27 22:39:46 +0100344 return 0;
345}
346
Wim Van Sebroeck35fcf532007-01-27 22:54:18 +0100347static void ibwdt_shutdown(struct platform_device *dev)
348{
349 /* Turn the WDT off if we have a soft shutdown */
350 ibwdt_disable();
351}
352
Wim Van Sebroeck745ac1ea2007-01-27 22:39:46 +0100353static struct platform_driver ibwdt_driver = {
354 .probe = ibwdt_probe,
355 .remove = __devexit_p(ibwdt_remove),
Wim Van Sebroeck35fcf532007-01-27 22:54:18 +0100356 .shutdown = ibwdt_shutdown,
Wim Van Sebroeck745ac1ea2007-01-27 22:39:46 +0100357 .driver = {
358 .owner = THIS_MODULE,
359 .name = DRV_NAME,
360 },
361};
362
363static int __init ibwdt_init(void)
364{
365 int err;
366
Alan Cox2e43ba72008-05-19 14:05:52 +0100367 printk(KERN_INFO PFX
368 "WDT driver for IB700 single board computer initialising.\n");
Wim Van Sebroeck745ac1ea2007-01-27 22:39:46 +0100369
370 err = platform_driver_register(&ibwdt_driver);
371 if (err)
372 return err;
373
Alan Cox2e43ba72008-05-19 14:05:52 +0100374 ibwdt_platform_device = platform_device_register_simple(DRV_NAME,
375 -1, NULL, 0);
Wim Van Sebroeck745ac1ea2007-01-27 22:39:46 +0100376 if (IS_ERR(ibwdt_platform_device)) {
377 err = PTR_ERR(ibwdt_platform_device);
378 goto unreg_platform_driver;
379 }
380
381 return 0;
382
383unreg_platform_driver:
384 platform_driver_unregister(&ibwdt_driver);
385 return err;
386}
387
388static void __exit ibwdt_exit(void)
389{
390 platform_device_unregister(ibwdt_platform_device);
391 platform_driver_unregister(&ibwdt_driver);
392 printk(KERN_INFO PFX "Watchdog Module Unloaded.\n");
Linus Torvalds1da177e2005-04-16 15:20:36 -0700393}
394
395module_init(ibwdt_init);
396module_exit(ibwdt_exit);
397
398MODULE_AUTHOR("Charles Howes <chowes@vsol.net>");
399MODULE_DESCRIPTION("IB700 SBC watchdog driver");
400MODULE_LICENSE("GPL");
401MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR);
402
403/* end of ib700wdt.c */