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
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
|
/*
* sma cpu5 watchdog driver
*
* Copyright (C) 2003 Heiko Ronsdorf <hero@ihg.uni-duisburg.de>
*
* 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.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
*
*/
#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
#include <linux/module.h>
#include <linux/moduleparam.h>
#include <linux/types.h>
#include <linux/errno.h>
#include <linux/miscdevice.h>
#include <linux/fs.h>
#include <linux/ioport.h>
#include <linux/timer.h>
#include <linux/completion.h>
#include <linux/jiffies.h>
#include <linux/io.h>
#include <linux/uaccess.h>
#include <linux/watchdog.h>
/* adjustable parameters */
static int verbose;
static int port = 0x91;
static int ticks = 10000;
static DEFINE_SPINLOCK(cpu5wdt_lock);
#define PFX "cpu5wdt: "
#define CPU5WDT_EXTENT 0x0A
#define CPU5WDT_STATUS_REG 0x00
#define CPU5WDT_TIME_A_REG 0x02
#define CPU5WDT_TIME_B_REG 0x03
#define CPU5WDT_MODE_REG 0x04
#define CPU5WDT_TRIGGER_REG 0x07
#define CPU5WDT_ENABLE_REG 0x08
#define CPU5WDT_RESET_REG 0x09
#define CPU5WDT_INTERVAL (HZ/10+1)
/* some device data */
static struct {
struct completion stop;
int running;
struct timer_list timer;
int queue;
int default_ticks;
unsigned long inuse;
} cpu5wdt_device;
/* generic helper functions */
static void cpu5wdt_trigger(struct timer_list *unused)
{
if (verbose > 2)
pr_debug("trigger at %i ticks\n", ticks);
if (cpu5wdt_device.running)
ticks--;
spin_lock(&cpu5wdt_lock);
/* keep watchdog alive */
outb(1, port + CPU5WDT_TRIGGER_REG);
/* requeue?? */
if (cpu5wdt_device.queue && ticks)
mod_timer(&cpu5wdt_device.timer, jiffies + CPU5WDT_INTERVAL);
else {
/* ticks doesn't matter anyway */
complete(&cpu5wdt_device.stop);
}
spin_unlock(&cpu5wdt_lock);
}
static void cpu5wdt_reset(void)
{
ticks = cpu5wdt_device.default_ticks;
if (verbose)
pr_debug("reset (%i ticks)\n", (int) ticks);
}
static void cpu5wdt_start(void)
{
unsigned long flags;
spin_lock_irqsave(&cpu5wdt_lock, flags);
if (!cpu5wdt_device.queue) {
cpu5wdt_device.queue = 1;
outb(0, port + CPU5WDT_TIME_A_REG);
outb(0, port + CPU5WDT_TIME_B_REG);
outb(1, port + CPU5WDT_MODE_REG);
outb(0, port + CPU5WDT_RESET_REG);
outb(0, port + CPU5WDT_ENABLE_REG);
mod_timer(&cpu5wdt_device.timer, jiffies + CPU5WDT_INTERVAL);
}
/* if process dies, counter is not decremented */
cpu5wdt_device.running++;
spin_unlock_irqrestore(&cpu5wdt_lock, flags);
}
static int cpu5wdt_stop(void)
{
unsigned long flags;
spin_lock_irqsave(&cpu5wdt_lock, flags);
if (cpu5wdt_device.running)
cpu5wdt_device.running = 0;
ticks = cpu5wdt_device.default_ticks;
spin_unlock_irqrestore(&cpu5wdt_lock, flags);
if (verbose)
pr_crit("stop not possible\n");
return -EIO;
}
/* filesystem operations */
static int cpu5wdt_open(struct inode *inode, struct file *file)
{
if (test_and_set_bit(0, &cpu5wdt_device.inuse))
return -EBUSY;
return nonseekable_open(inode, file);
}
static int cpu5wdt_release(struct inode *inode, struct file *file)
{
clear_bit(0, &cpu5wdt_device.inuse);
return 0;
}
static long cpu5wdt_ioctl(struct file *file, unsigned int cmd,
unsigned long arg)
{
void __user *argp = (void __user *)arg;
int __user *p = argp;
unsigned int value;
static const struct watchdog_info ident = {
.options = WDIOF_CARDRESET,
.identity = "CPU5 WDT",
};
switch (cmd) {
case WDIOC_GETSUPPORT:
if (copy_to_user(argp, &ident, sizeof(ident)))
return -EFAULT;
break;
case WDIOC_GETSTATUS:
value = inb(port + CPU5WDT_STATUS_REG);
value = (value >> 2) & 1;
return put_user(value, p);
case WDIOC_GETBOOTSTATUS:
return put_user(0, p);
case WDIOC_SETOPTIONS:
if (get_user(value, p))
return -EFAULT;
if (value & WDIOS_ENABLECARD)
cpu5wdt_start();
if (value & WDIOS_DISABLECARD)
cpu5wdt_stop();
break;
case WDIOC_KEEPALIVE:
cpu5wdt_reset();
break;
default:
return -ENOTTY;
}
return 0;
}
static ssize_t cpu5wdt_write(struct file *file, const char __user *buf,
size_t count, loff_t *ppos)
{
if (!count)
return -EIO;
cpu5wdt_reset();
return count;
}
static const struct file_operations cpu5wdt_fops = {
.owner = THIS_MODULE,
.llseek = no_llseek,
.unlocked_ioctl = cpu5wdt_ioctl,
.open = cpu5wdt_open,
.write = cpu5wdt_write,
.release = cpu5wdt_release,
};
static struct miscdevice cpu5wdt_misc = {
.minor = WATCHDOG_MINOR,
.name = "watchdog",
.fops = &cpu5wdt_fops,
};
/* init/exit function */
static int cpu5wdt_init(void)
{
unsigned int val;
int err;
if (verbose)
pr_debug("port=0x%x, verbose=%i\n", port, verbose);
init_completion(&cpu5wdt_device.stop);
cpu5wdt_device.queue = 0;
timer_setup(&cpu5wdt_device.timer, cpu5wdt_trigger, 0);
cpu5wdt_device.default_ticks = ticks;
if (!request_region(port, CPU5WDT_EXTENT, PFX)) {
pr_err("request_region failed\n");
err = -EBUSY;
goto no_port;
}
/* watchdog reboot? */
val = inb(port + CPU5WDT_STATUS_REG);
val = (val >> 2) & 1;
if (!val)
pr_info("sorry, was my fault\n");
err = misc_register(&cpu5wdt_misc);
if (err < 0) {
pr_err("misc_register failed\n");
goto no_misc;
}
pr_info("init success\n");
return 0;
no_misc:
release_region(port, CPU5WDT_EXTENT);
no_port:
return err;
}
static int cpu5wdt_init_module(void)
{
return cpu5wdt_init();
}
static void cpu5wdt_exit(void)
{
if (cpu5wdt_device.queue) {
cpu5wdt_device.queue = 0;
wait_for_completion(&cpu5wdt_device.stop);
del_timer(&cpu5wdt_device.timer);
}
misc_deregister(&cpu5wdt_misc);
release_region(port, CPU5WDT_EXTENT);
}
static void cpu5wdt_exit_module(void)
{
cpu5wdt_exit();
}
/* module entry points */
module_init(cpu5wdt_init_module);
module_exit(cpu5wdt_exit_module);
MODULE_AUTHOR("Heiko Ronsdorf <hero@ihg.uni-duisburg.de>");
MODULE_DESCRIPTION("sma cpu5 watchdog driver");
MODULE_SUPPORTED_DEVICE("sma cpu5 watchdog");
MODULE_LICENSE("GPL");
module_param_hw(port, int, ioport, 0);
MODULE_PARM_DESC(port, "base address of watchdog card, default is 0x91");
module_param(verbose, int, 0);
MODULE_PARM_DESC(verbose, "be verbose, default is 0 (no)");
module_param(ticks, int, 0);
MODULE_PARM_DESC(ticks, "count down ticks, default is 10000");
|
