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authorLinus Torvalds <torvalds@ppc970.osdl.org>2005-04-16 18:20:36 -0400
committerLinus Torvalds <torvalds@ppc970.osdl.org>2005-04-16 18:20:36 -0400
commit1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 (patch)
tree0bba044c4ce775e45a88a51686b5d9f90697ea9d /drivers/char/watchdog/ib700wdt.c
Linux-2.6.12-rc2v2.6.12-rc2
Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
Diffstat (limited to 'drivers/char/watchdog/ib700wdt.c')
-rw-r--r--drivers/char/watchdog/ib700wdt.c352
1 files changed, 352 insertions, 0 deletions
diff --git a/drivers/char/watchdog/ib700wdt.c b/drivers/char/watchdog/ib700wdt.c
new file mode 100644
index 000000000000..d974f16e84d2
--- /dev/null
+++ b/drivers/char/watchdog/ib700wdt.c
@@ -0,0 +1,352 @@
1/*
2 * IB700 Single Board Computer WDT driver
3 *
4 * (c) Copyright 2001 Charles Howes <chowes@vsol.net>
5 *
6 * Based on advantechwdt.c which is based on acquirewdt.c which
7 * is based on wdt.c.
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 *
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 *
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
31 *
32 */
33
34#include <linux/config.h>
35#include <linux/module.h>
36#include <linux/types.h>
37#include <linux/miscdevice.h>
38#include <linux/watchdog.h>
39#include <linux/ioport.h>
40#include <linux/notifier.h>
41#include <linux/fs.h>
42#include <linux/reboot.h>
43#include <linux/init.h>
44#include <linux/spinlock.h>
45#include <linux/moduleparam.h>
46
47#include <asm/io.h>
48#include <asm/uaccess.h>
49#include <asm/system.h>
50
51static unsigned long ibwdt_is_open;
52static spinlock_t ibwdt_lock;
53static char expect_close;
54
55#define PFX "ib700wdt: "
56
57/*
58 *
59 * Watchdog Timer Configuration
60 *
61 * The function of the watchdog timer is to reset the system
62 * automatically and is defined at I/O port 0443H. To enable the
63 * watchdog timer and allow the system to reset, write I/O port 0443H.
64 * To disable the timer, write I/O port 0441H for the system to stop the
65 * watchdog function. The timer has a tolerance of 20% for its
66 * intervals.
67 *
68 * The following describes how the timer should be programmed.
69 *
70 * Enabling Watchdog:
71 * MOV AX,000FH (Choose the values from 0 to F)
72 * MOV DX,0443H
73 * OUT DX,AX
74 *
75 * Disabling Watchdog:
76 * MOV AX,000FH (Any value is fine.)
77 * MOV DX,0441H
78 * OUT DX,AX
79 *
80 * Watchdog timer control table:
81 * Level Value Time/sec | Level Value Time/sec
82 * 1 F 0 | 9 7 16
83 * 2 E 2 | 10 6 18
84 * 3 D 4 | 11 5 20
85 * 4 C 6 | 12 4 22
86 * 5 B 8 | 13 3 24
87 * 6 A 10 | 14 2 26
88 * 7 9 12 | 15 1 28
89 * 8 8 14 | 16 0 30
90 *
91 */
92
93static int wd_times[] = {
94 30, /* 0x0 */
95 28, /* 0x1 */
96 26, /* 0x2 */
97 24, /* 0x3 */
98 22, /* 0x4 */
99 20, /* 0x5 */
100 18, /* 0x6 */
101 16, /* 0x7 */
102 14, /* 0x8 */
103 12, /* 0x9 */
104 10, /* 0xA */
105 8, /* 0xB */
106 6, /* 0xC */
107 4, /* 0xD */
108 2, /* 0xE */
109 0, /* 0xF */
110};
111
112#define WDT_STOP 0x441
113#define WDT_START 0x443
114
115/* Default timeout */
116#define WD_TIMO 0 /* 30 seconds +/- 20%, from table */
117
118static int wd_margin = WD_TIMO;
119
120#ifdef CONFIG_WATCHDOG_NOWAYOUT
121static int nowayout = 1;
122#else
123static int nowayout = 0;
124#endif
125
126module_param(nowayout, int, 0);
127MODULE_PARM_DESC(nowayout, "Watchdog cannot be stopped once started (default=CONFIG_WATCHDOG_NOWAYOUT)");
128
129
130/*
131 * Kernel methods.
132 */
133
134static void
135ibwdt_ping(void)
136{
137 /* Write a watchdog value */
138 outb_p(wd_margin, WDT_START);
139}
140
141static ssize_t
142ibwdt_write(struct file *file, const char __user *buf, size_t count, loff_t *ppos)
143{
144 if (count) {
145 if (!nowayout) {
146 size_t i;
147
148 /* In case it was set long ago */
149 expect_close = 0;
150
151 for (i = 0; i != count; i++) {
152 char c;
153 if (get_user(c, buf + i))
154 return -EFAULT;
155 if (c == 'V')
156 expect_close = 42;
157 }
158 }
159 ibwdt_ping();
160 }
161 return count;
162}
163
164static int
165ibwdt_ioctl(struct inode *inode, struct file *file, unsigned int cmd,
166 unsigned long arg)
167{
168 int i, new_margin;
169 void __user *argp = (void __user *)arg;
170 int __user *p = argp;
171
172 static struct watchdog_info ident = {
173 .options = WDIOF_KEEPALIVEPING | WDIOF_SETTIMEOUT | WDIOF_MAGICCLOSE,
174 .firmware_version = 1,
175 .identity = "IB700 WDT",
176 };
177
178 switch (cmd) {
179 case WDIOC_GETSUPPORT:
180 if (copy_to_user(argp, &ident, sizeof(ident)))
181 return -EFAULT;
182 break;
183
184 case WDIOC_GETSTATUS:
185 return put_user(0, p);
186
187 case WDIOC_KEEPALIVE:
188 ibwdt_ping();
189 break;
190
191 case WDIOC_SETTIMEOUT:
192 if (get_user(new_margin, p))
193 return -EFAULT;
194 if ((new_margin < 0) || (new_margin > 30))
195 return -EINVAL;
196 for (i = 0x0F; i > -1; i--)
197 if (wd_times[i] > new_margin)
198 break;
199 wd_margin = i;
200 ibwdt_ping();
201 /* Fall */
202
203 case WDIOC_GETTIMEOUT:
204 return put_user(wd_times[wd_margin], p);
205 break;
206
207 default:
208 return -ENOIOCTLCMD;
209 }
210 return 0;
211}
212
213static int
214ibwdt_open(struct inode *inode, struct file *file)
215{
216 spin_lock(&ibwdt_lock);
217 if (test_and_set_bit(0, &ibwdt_is_open)) {
218 spin_unlock(&ibwdt_lock);
219 return -EBUSY;
220 }
221 if (nowayout)
222 __module_get(THIS_MODULE);
223
224 /* Activate */
225 ibwdt_ping();
226 spin_unlock(&ibwdt_lock);
227 return nonseekable_open(inode, file);
228}
229
230static int
231ibwdt_close(struct inode *inode, struct file *file)
232{
233 spin_lock(&ibwdt_lock);
234 if (expect_close == 42)
235 outb_p(0, WDT_STOP);
236 else
237 printk(KERN_CRIT PFX "WDT device closed unexpectedly. WDT will not stop!\n");
238
239 clear_bit(0, &ibwdt_is_open);
240 expect_close = 0;
241 spin_unlock(&ibwdt_lock);
242 return 0;
243}
244
245/*
246 * Notifier for system down
247 */
248
249static int
250ibwdt_notify_sys(struct notifier_block *this, unsigned long code,
251 void *unused)
252{
253 if (code == SYS_DOWN || code == SYS_HALT) {
254 /* Turn the WDT off */
255 outb_p(0, WDT_STOP);
256 }
257 return NOTIFY_DONE;
258}
259
260/*
261 * Kernel Interfaces
262 */
263
264static struct file_operations ibwdt_fops = {
265 .owner = THIS_MODULE,
266 .llseek = no_llseek,
267 .write = ibwdt_write,
268 .ioctl = ibwdt_ioctl,
269 .open = ibwdt_open,
270 .release = ibwdt_close,
271};
272
273static struct miscdevice ibwdt_miscdev = {
274 .minor = WATCHDOG_MINOR,
275 .name = "watchdog",
276 .fops = &ibwdt_fops,
277};
278
279/*
280 * The WDT needs to learn about soft shutdowns in order to
281 * turn the timebomb registers off.
282 */
283
284static struct notifier_block ibwdt_notifier = {
285 .notifier_call = ibwdt_notify_sys,
286};
287
288static int __init ibwdt_init(void)
289{
290 int res;
291
292 printk(KERN_INFO PFX "WDT driver for IB700 single board computer initialising.\n");
293
294 spin_lock_init(&ibwdt_lock);
295 res = misc_register(&ibwdt_miscdev);
296 if (res) {
297 printk (KERN_ERR PFX "failed to register misc device\n");
298 goto out_nomisc;
299 }
300
301#if WDT_START != WDT_STOP
302 if (!request_region(WDT_STOP, 1, "IB700 WDT")) {
303 printk (KERN_ERR PFX "STOP method I/O %X is not available.\n", WDT_STOP);
304 res = -EIO;
305 goto out_nostopreg;
306 }
307#endif
308
309 if (!request_region(WDT_START, 1, "IB700 WDT")) {
310 printk (KERN_ERR PFX "START method I/O %X is not available.\n", WDT_START);
311 res = -EIO;
312 goto out_nostartreg;
313 }
314 res = register_reboot_notifier(&ibwdt_notifier);
315 if (res) {
316 printk (KERN_ERR PFX "Failed to register reboot notifier.\n");
317 goto out_noreboot;
318 }
319 return 0;
320
321out_noreboot:
322 release_region(WDT_START, 1);
323out_nostartreg:
324#if WDT_START != WDT_STOP
325 release_region(WDT_STOP, 1);
326#endif
327out_nostopreg:
328 misc_deregister(&ibwdt_miscdev);
329out_nomisc:
330 return res;
331}
332
333static void __exit
334ibwdt_exit(void)
335{
336 misc_deregister(&ibwdt_miscdev);
337 unregister_reboot_notifier(&ibwdt_notifier);
338#if WDT_START != WDT_STOP
339 release_region(WDT_STOP,1);
340#endif
341 release_region(WDT_START,1);
342}
343
344module_init(ibwdt_init);
345module_exit(ibwdt_exit);
346
347MODULE_AUTHOR("Charles Howes <chowes@vsol.net>");
348MODULE_DESCRIPTION("IB700 SBC watchdog driver");
349MODULE_LICENSE("GPL");
350MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR);
351
352/* end of ib700wdt.c */