1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
|
/*
* IndyDog 0.3 A Hardware Watchdog Device for SGI IP22
*
* (c) Copyright 2002 Guido Guenther <agx@sigxcpu.org>,
* All Rights Reserved.
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License
* as published by the Free Software Foundation; either version
* 2 of the License, or (at your option) any later version.
*
* based on softdog.c by Alan Cox <alan@redhat.com>
*/
#include <linux/module.h>
#include <linux/moduleparam.h>
#include <linux/types.h>
#include <linux/kernel.h>
#include <linux/fs.h>
#include <linux/mm.h>
#include <linux/miscdevice.h>
#include <linux/watchdog.h>
#include <linux/notifier.h>
#include <linux/reboot.h>
#include <linux/init.h>
#include <linux/uaccess.h>
#include <asm/sgi/mc.h>
#define PFX "indydog: "
static unsigned long indydog_alive;
static spinlock_t indydog_lock;
#define WATCHDOG_TIMEOUT 30 /* 30 sec default timeout */
static int nowayout = WATCHDOG_NOWAYOUT;
module_param(nowayout, int, 0);
MODULE_PARM_DESC(nowayout,
"Watchdog cannot be stopped once started (default="
__MODULE_STRING(WATCHDOG_NOWAYOUT) ")");
static void indydog_start(void)
{
u32 mc_ctrl0;
spin_lock(&indydog_lock);
mc_ctrl0 = sgimc->cpuctrl0;
mc_ctrl0 = sgimc->cpuctrl0 | SGIMC_CCTRL0_WDOG;
sgimc->cpuctrl0 = mc_ctrl0;
spin_unlock(&indydog_lock);
}
static void indydog_stop(void)
{
u32 mc_ctrl0;
spin_lock(&indydog_lock);
mc_ctrl0 = sgimc->cpuctrl0;
mc_ctrl0 &= ~SGIMC_CCTRL0_WDOG;
sgimc->cpuctrl0 = mc_ctrl0;
spin_unlock(&indydog_lock);
printk(KERN_INFO PFX "Stopped watchdog timer.\n");
}
static void indydog_ping(void)
{
sgimc->watchdogt = 0;
}
/*
* Allow only one person to hold it open
*/
static int indydog_open(struct inode *inode, struct file *file)
{
if (test_and_set_bit(0, &indydog_alive))
return -EBUSY;
if (nowayout)
__module_get(THIS_MODULE);
/* Activate timer */
indydog_start();
indydog_ping();
indydog_alive = 1;
printk(KERN_INFO "Started watchdog timer.\n");
return nonseekable_open(inode, file);
}
static int indydog_release(struct inode *inode, struct file *file)
{
/* Shut off the timer.
* Lock it in if it's a module and we defined ...NOWAYOUT */
if (!nowayout)
indydog_stop(); /* Turn the WDT off */
clear_bit(0, &indydog_alive);
return 0;
}
static ssize_t indydog_write(struct file *file, const char *data,
size_t len, loff_t *ppos)
{
/* Refresh the timer. */
if (len)
indydog_ping();
return len;
}
static long indydog_ioctl(struct file *file, unsigned int cmd,
unsigned long arg)
{
int options, retval = -EINVAL;
static struct watchdog_info ident = {
.options = WDIOF_KEEPALIVEPING |
WDIOF_MAGICCLOSE,
.firmware_version = 0,
.identity = "Hardware Watchdog for SGI IP22",
};
switch (cmd) {
case WDIOC_GETSUPPORT:
if (copy_to_user((struct watchdog_info *)arg,
&ident, sizeof(ident)))
return -EFAULT;
return 0;
case WDIOC_GETSTATUS:
case WDIOC_GETBOOTSTATUS:
return put_user(0, (int *)arg);
case WDIOC_KEEPALIVE:
indydog_ping();
return 0;
case WDIOC_GETTIMEOUT:
return put_user(WATCHDOG_TIMEOUT, (int *)arg);
case WDIOC_SETOPTIONS:
{
if (get_user(options, (int *)arg))
return -EFAULT;
if (options & WDIOS_DISABLECARD) {
indydog_stop();
retval = 0;
}
if (options & WDIOS_ENABLECARD) {
indydog_start();
retval = 0;
}
return retval;
}
default:
return -ENOTTY;
}
}
static int indydog_notify_sys(struct notifier_block *this,
unsigned long code, void *unused)
{
if (code == SYS_DOWN || code == SYS_HALT)
indydog_stop(); /* Turn the WDT off */
return NOTIFY_DONE;
}
static const struct file_operations indydog_fops = {
.owner = THIS_MODULE,
.llseek = no_llseek,
.write = indydog_write,
.unlocked_ioctl = indydog_ioctl,
.open = indydog_open,
.release = indydog_release,
};
static struct miscdevice indydog_miscdev = {
.minor = WATCHDOG_MINOR,
.name = "watchdog",
.fops = &indydog_fops,
};
static struct notifier_block indydog_notifier = {
.notifier_call = indydog_notify_sys,
};
static char banner[] __initdata =
KERN_INFO PFX "Hardware Watchdog Timer for SGI IP22: 0.3\n";
static int __init watchdog_init(void)
{
int ret;
spin_lock_init(&indydog_lock);
ret = register_reboot_notifier(&indydog_notifier);
if (ret) {
printk(KERN_ERR PFX
"cannot register reboot notifier (err=%d)\n", ret);
return ret;
}
ret = misc_register(&indydog_miscdev);
if (ret) {
printk(KERN_ERR PFX
"cannot register miscdev on minor=%d (err=%d)\n",
WATCHDOG_MINOR, ret);
unregister_reboot_notifier(&indydog_notifier);
return ret;
}
printk(banner);
return 0;
}
static void __exit watchdog_exit(void)
{
misc_deregister(&indydog_miscdev);
unregister_reboot_notifier(&indydog_notifier);
}
module_init(watchdog_init);
module_exit(watchdog_exit);
MODULE_AUTHOR("Guido Guenther <agx@sigxcpu.org>");
MODULE_DESCRIPTION("Hardware Watchdog Device for SGI IP22");
MODULE_LICENSE("GPL");
MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR);
|
