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
|
/*
* Intel 21285 watchdog driver
* Copyright (c) Phil Blundell <pb@nexus.co.uk>, 1998
*
* based on
*
* SoftDog 0.05: A Software Watchdog Device
*
* (c) Copyright 1996 Alan Cox <alan@redhat.com>, 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.
*
*/
#include <linux/module.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/reboot.h>
#include <linux/init.h>
#include <linux/interrupt.h>
#include <linux/smp_lock.h>
#include <asm/irq.h>
#include <asm/uaccess.h>
#include <asm/hardware.h>
#include <asm/mach-types.h>
#include <asm/hardware/dec21285.h>
/*
* Define this to stop the watchdog actually rebooting the machine.
*/
#undef ONLY_TESTING
#define TIMER_MARGIN 60 /* (secs) Default is 1 minute */
#define FCLK (50*1000*1000) /* 50MHz */
static int soft_margin = TIMER_MARGIN; /* in seconds */
static int timer_alive;
#ifdef ONLY_TESTING
/*
* If the timer expires..
*/
static void watchdog_fire(int irq, void *dev_id, struct pt_regs *regs)
{
printk(KERN_CRIT "Watchdog: Would Reboot.\n");
*CSR_TIMER4_CNTL = 0;
*CSR_TIMER4_CLR = 0;
}
#endif
static void watchdog_ping(void)
{
/*
* Refresh the timer.
*/
*CSR_TIMER4_LOAD = soft_margin * (FCLK / 256);
}
/*
* Allow only one person to hold it open
*/
static int watchdog_open(struct inode *inode, struct file *file)
{
if(timer_alive)
return -EBUSY;
/*
* Ahead watchdog factor ten, Mr Sulu
*/
*CSR_TIMER4_CLR = 0;
watchdog_ping();
*CSR_TIMER4_CNTL = TIMER_CNTL_ENABLE | TIMER_CNTL_AUTORELOAD
| TIMER_CNTL_DIV256;
#ifdef ONLY_TESTING
request_irq(IRQ_TIMER4, watchdog_fire, 0, "watchdog", NULL);
#else
*CSR_SA110_CNTL |= 1 << 13;
MOD_INC_USE_COUNT;
#endif
timer_alive = 1;
return 0;
}
static int watchdog_release(struct inode *inode, struct file *file)
{
#ifdef ONLY_TESTING
lock_kernel();
free_irq(IRQ_TIMER4, NULL);
timer_alive = 0;
unlock_kernel();
#else
/*
* It's irreversible!
*/
#endif
return 0;
}
static ssize_t watchdog_write(struct file *file, const char *data, size_t len, loff_t *ppos)
{
/* Can't seek (pwrite) on this device */
if (ppos != &file->f_pos)
return -ESPIPE;
/*
* Refresh the timer.
*/
if(len)
{
watchdog_ping();
return 1;
}
return 0;
}
static int watchdog_ioctl(struct inode *inode, struct file *file,
unsigned int cmd, unsigned long arg)
{
int i;
static struct watchdog_info ident=
{
0,
0,
"Footbridge Watchdog"
};
switch(cmd)
{
default:
return -ENOIOCTLCMD;
case WDIOC_GETSUPPORT:
i = verify_area(VERIFY_WRITE, (void*) arg, sizeof(struct watchdog_info));
if (i)
return i;
else
return copy_to_user((struct watchdog_info *)arg, &ident, sizeof(ident));
case WDIOC_GETSTATUS:
case WDIOC_GETBOOTSTATUS:
return put_user(0,(int *)arg);
case WDIOC_KEEPALIVE:
watchdog_ping();
return 0;
}
}
static struct file_operations watchdog_fops=
{
owner: THIS_MODULE,
write: watchdog_write,
ioctl: watchdog_ioctl,
open: watchdog_open,
release: watchdog_release,
};
static struct miscdevice watchdog_miscdev=
{
WATCHDOG_MINOR,
"watchdog",
&watchdog_fops
};
static int __init footbridge_watchdog_init(void)
{
if (machine_is_netwinder())
return -ENODEV;
misc_register(&watchdog_miscdev);
printk("Footbridge Watchdog Timer: 0.01, timer margin: %d sec\n",
soft_margin);
if (machine_is_cats())
printk("Warning: Watchdog reset may not work on this machine.\n");
return 0;
}
static void __exit footbridge_watchdog_exit(void)
{
misc_deregister(&watchdog_miscdev);
}
EXPORT_NO_SYMBOLS;
MODULE_AUTHOR("Phil Blundell <pb@nexus.co.uk>");
MODULE_DESCRIPTION("21285 watchdog driver");
MODULE_PARM(soft_margin,"i");
MODULE_PARM_DESC(soft_margin,"Watchdog timeout in seconds");
module_init(footbridge_watchdog_init);
module_exit(footbridge_watchdog_exit);
|
