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
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
|
/*
* Watchdog driver for SBC-FITPC2 board
*
* Author: Denis Turischev <denis@compulab.co.il>
*
* Adapted from the IXP2000 watchdog driver by Deepak Saxena.
*
* This file is licensed under the terms of the GNU General Public
* License version 2. This program is licensed "as is" without any
* warranty of any kind, whether express or implied.
*/
#define pr_fmt(fmt) KBUILD_MODNAME " WATCHDOG: " fmt
#include <linux/module.h>
#include <linux/types.h>
#include <linux/miscdevice.h>
#include <linux/watchdog.h>
#include <linux/ioport.h>
#include <linux/delay.h>
#include <linux/fs.h>
#include <linux/init.h>
#include <linux/moduleparam.h>
#include <linux/dmi.h>
#include <linux/io.h>
#include <linux/uaccess.h>
#include <asm/system.h>
static int nowayout = WATCHDOG_NOWAYOUT;
static unsigned int margin = 60; /* (secs) Default is 1 minute */
static unsigned long wdt_status;
static DEFINE_MUTEX(wdt_lock);
#define WDT_IN_USE 0
#define WDT_OK_TO_CLOSE 1
#define COMMAND_PORT 0x4c
#define DATA_PORT 0x48
#define IFACE_ON_COMMAND 1
#define REBOOT_COMMAND 2
#define WATCHDOG_NAME "SBC-FITPC2 Watchdog"
static void wdt_send_data(unsigned char command, unsigned char data)
{
outb(data, DATA_PORT);
msleep(200);
outb(command, COMMAND_PORT);
msleep(100);
}
static void wdt_enable(void)
{
mutex_lock(&wdt_lock);
wdt_send_data(IFACE_ON_COMMAND, 1);
wdt_send_data(REBOOT_COMMAND, margin);
mutex_unlock(&wdt_lock);
}
static void wdt_disable(void)
{
mutex_lock(&wdt_lock);
wdt_send_data(IFACE_ON_COMMAND, 0);
wdt_send_data(REBOOT_COMMAND, 0);
mutex_unlock(&wdt_lock);
}
static int fitpc2_wdt_open(struct inode *inode, struct file *file)
{
if (test_and_set_bit(WDT_IN_USE, &wdt_status))
return -EBUSY;
clear_bit(WDT_OK_TO_CLOSE, &wdt_status);
wdt_enable();
return nonseekable_open(inode, file);
}
static ssize_t fitpc2_wdt_write(struct file *file, const char *data,
size_t len, loff_t *ppos)
{
size_t i;
if (!len)
return 0;
if (nowayout) {
len = 0;
goto out;
}
clear_bit(WDT_OK_TO_CLOSE, &wdt_status);
for (i = 0; i != len; i++) {
char c;
if (get_user(c, data + i))
return -EFAULT;
if (c == 'V')
set_bit(WDT_OK_TO_CLOSE, &wdt_status);
}
out:
wdt_enable();
return len;
}
static const struct watchdog_info ident = {
.options = WDIOF_MAGICCLOSE | WDIOF_SETTIMEOUT |
WDIOF_KEEPALIVEPING,
.identity = WATCHDOG_NAME,
};
static long fitpc2_wdt_ioctl(struct file *file, unsigned int cmd,
unsigned long arg)
{
int ret = -ENOTTY;
int time;
switch (cmd) {
case WDIOC_GETSUPPORT:
ret = copy_to_user((struct watchdog_info *)arg, &ident,
sizeof(ident)) ? -EFAULT : 0;
break;
case WDIOC_GETSTATUS:
ret = put_user(0, (int *)arg);
break;
case WDIOC_GETBOOTSTATUS:
ret = put_user(0, (int *)arg);
break;
case WDIOC_KEEPALIVE:
wdt_enable();
ret = 0;
break;
case WDIOC_SETTIMEOUT:
ret = get_user(time, (int *)arg);
if (ret)
break;
if (time < 31 || time > 255) {
ret = -EINVAL;
break;
}
margin = time;
wdt_enable();
/* Fall through */
case WDIOC_GETTIMEOUT:
ret = put_user(margin, (int *)arg);
break;
}
return ret;
}
static int fitpc2_wdt_release(struct inode *inode, struct file *file)
{
if (test_bit(WDT_OK_TO_CLOSE, &wdt_status)) {
wdt_disable();
pr_info("Device disabled\n");
} else {
pr_warning("Device closed unexpectedly -"
" timer will not stop\n");
wdt_enable();
}
clear_bit(WDT_IN_USE, &wdt_status);
clear_bit(WDT_OK_TO_CLOSE, &wdt_status);
return 0;
}
static const struct file_operations fitpc2_wdt_fops = {
.owner = THIS_MODULE,
.llseek = no_llseek,
.write = fitpc2_wdt_write,
.unlocked_ioctl = fitpc2_wdt_ioctl,
.open = fitpc2_wdt_open,
.release = fitpc2_wdt_release,
};
static struct miscdevice fitpc2_wdt_miscdev = {
.minor = WATCHDOG_MINOR,
.name = "watchdog",
.fops = &fitpc2_wdt_fops,
};
static int __init fitpc2_wdt_init(void)
{
int err;
if (!strstr(dmi_get_system_info(DMI_BOARD_NAME), "SBC-FITPC2"))
return -ENODEV;
pr_info("%s found\n", dmi_get_system_info(DMI_BOARD_NAME));
if (!request_region(COMMAND_PORT, 1, WATCHDOG_NAME)) {
pr_err("I/O address 0x%04x already in use\n", COMMAND_PORT);
return -EIO;
}
if (!request_region(DATA_PORT, 1, WATCHDOG_NAME)) {
pr_err("I/O address 0x%04x already in use\n", DATA_PORT);
err = -EIO;
goto err_data_port;
}
if (margin < 31 || margin > 255) {
pr_err("margin must be in range 31 - 255"
" seconds, you tried to set %d\n", margin);
err = -EINVAL;
goto err_margin;
}
err = misc_register(&fitpc2_wdt_miscdev);
if (err) {
pr_err("cannot register miscdev on minor=%d (err=%d)\n",
WATCHDOG_MINOR, err);
goto err_margin;
}
return 0;
err_margin:
release_region(DATA_PORT, 1);
err_data_port:
release_region(COMMAND_PORT, 1);
return err;
}
static void __exit fitpc2_wdt_exit(void)
{
misc_deregister(&fitpc2_wdt_miscdev);
release_region(DATA_PORT, 1);
release_region(COMMAND_PORT, 1);
}
module_init(fitpc2_wdt_init);
module_exit(fitpc2_wdt_exit);
MODULE_AUTHOR("Denis Turischev <denis@compulab.co.il>");
MODULE_DESCRIPTION("SBC-FITPC2 Watchdog");
module_param(margin, int, 0);
MODULE_PARM_DESC(margin, "Watchdog margin in seconds (default 60s)");
module_param(nowayout, int, 0);
MODULE_PARM_DESC(nowayout, "Watchdog cannot be stopped once started");
MODULE_LICENSE("GPL");
MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR);
|
