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
|
/*
* SBC EPX C3 0.1 A Hardware Watchdog Device for the Winsystems EPX-C3
* single board computer
*
* (c) Copyright 2006 Calin A. Culianu <calin@ajvar.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/ioport.h>
#include <linux/uaccess.h>
#include <linux/io.h>
#define PFX "epx_c3: "
static int epx_c3_alive;
#define WATCHDOG_TIMEOUT 1 /* 1 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) ")");
#define EPXC3_WATCHDOG_CTL_REG 0x1ee /* write 1 to enable, 0 to disable */
#define EPXC3_WATCHDOG_PET_REG 0x1ef /* write anything to pet once enabled */
static void epx_c3_start(void)
{
outb(1, EPXC3_WATCHDOG_CTL_REG);
}
static void epx_c3_stop(void)
{
outb(0, EPXC3_WATCHDOG_CTL_REG);
printk(KERN_INFO PFX "Stopped watchdog timer.\n");
}
static void epx_c3_pet(void)
{
outb(1, EPXC3_WATCHDOG_PET_REG);
}
/*
* Allow only one person to hold it open
*/
static int epx_c3_open(struct inode *inode, struct file *file)
{
if (epx_c3_alive)
return -EBUSY;
if (nowayout)
__module_get(THIS_MODULE);
/* Activate timer */
epx_c3_start();
epx_c3_pet();
epx_c3_alive = 1;
printk(KERN_INFO "Started watchdog timer.\n");
return nonseekable_open(inode, file);
}
static int epx_c3_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)
epx_c3_stop(); /* Turn the WDT off */
epx_c3_alive = 0;
return 0;
}
static ssize_t epx_c3_write(struct file *file, const char __user *data,
size_t len, loff_t *ppos)
{
/* Refresh the timer. */
if (len)
epx_c3_pet();
return len;
}
static long epx_c3_ioctl(struct file *file, unsigned int cmd,
unsigned long arg)
{
int options, retval = -EINVAL;
int __user *argp = (void __user *)arg;
static const struct watchdog_info ident = {
.options = WDIOF_KEEPALIVEPING |
WDIOF_MAGICCLOSE,
.firmware_version = 0,
.identity = "Winsystems EPX-C3 H/W Watchdog",
};
switch (cmd) {
case WDIOC_GETSUPPORT:
if (copy_to_user(argp, &ident, sizeof(ident)))
return -EFAULT;
return 0;
case WDIOC_GETSTATUS:
case WDIOC_GETBOOTSTATUS:
return put_user(0, argp);
case WDIOC_SETOPTIONS:
if (get_user(options, argp))
return -EFAULT;
if (options & WDIOS_DISABLECARD) {
epx_c3_stop();
retval = 0;
}
if (options & WDIOS_ENABLECARD) {
epx_c3_start();
retval = 0;
}
return retval;
case WDIOC_KEEPALIVE:
epx_c3_pet();
return 0;
case WDIOC_GETTIMEOUT:
return put_user(WATCHDOG_TIMEOUT, argp);
default:
return -ENOTTY;
}
}
static int epx_c3_notify_sys(struct notifier_block *this, unsigned long code,
void *unused)
{
if (code == SYS_DOWN || code == SYS_HALT)
epx_c3_stop(); /* Turn the WDT off */
return NOTIFY_DONE;
}
static const struct file_operations epx_c3_fops = {
.owner = THIS_MODULE,
.llseek = no_llseek,
.write = epx_c3_write,
.unlocked_ioctl = epx_c3_ioctl,
.open = epx_c3_open,
.release = epx_c3_release,
};
static struct miscdevice epx_c3_miscdev = {
.minor = WATCHDOG_MINOR,
.name = "watchdog",
.fops = &epx_c3_fops,
};
static struct notifier_block epx_c3_notifier = {
.notifier_call = epx_c3_notify_sys,
};
static const char banner[] __initdata =
KERN_INFO PFX "Hardware Watchdog Timer for Winsystems EPX-C3 SBC: 0.1\n";
static int __init watchdog_init(void)
{
int ret;
if (!request_region(EPXC3_WATCHDOG_CTL_REG, 2, "epxc3_watchdog"))
return -EBUSY;
ret = register_reboot_notifier(&epx_c3_notifier);
if (ret) {
printk(KERN_ERR PFX "cannot register reboot notifier "
"(err=%d)\n", ret);
goto out;
}
ret = misc_register(&epx_c3_miscdev);
if (ret) {
printk(KERN_ERR PFX "cannot register miscdev on minor=%d "
"(err=%d)\n", WATCHDOG_MINOR, ret);
unregister_reboot_notifier(&epx_c3_notifier);
goto out;
}
printk(banner);
return 0;
out:
release_region(EPXC3_WATCHDOG_CTL_REG, 2);
return ret;
}
static void __exit watchdog_exit(void)
{
misc_deregister(&epx_c3_miscdev);
unregister_reboot_notifier(&epx_c3_notifier);
release_region(EPXC3_WATCHDOG_CTL_REG, 2);
}
module_init(watchdog_init);
module_exit(watchdog_exit);
MODULE_AUTHOR("Calin A. Culianu <calin@ajvar.org>");
MODULE_DESCRIPTION("Hardware Watchdog Device for Winsystems EPX-C3 SBC. Note that there is no way to probe for this device -- so only use it if you are *sure* you are runnning on this specific SBC system from Winsystems! It writes to IO ports 0x1ee and 0x1ef!");
MODULE_LICENSE("GPL");
MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR);
|
