1 /*
2 * Copyright (C) 2012 The Android Open Source Project
3 *
4 * Licensed under the Apache License, Version 2.0 (the "License");
5 * you may not use this file except in compliance with the License.
6 * You may obtain a copy of the License at
7 *
8 * http://www.apache.org/licenses/LICENSE-2.0
9 *
10 * Unless required by applicable law or agreed to in writing, software
11 * distributed under the License is distributed on an "AS IS" BASIS,
12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13 * See the License for the specific language governing permissions and
14 * limitations under the License.
15 */
16
17 #include <errno.h>
18 #include <fcntl.h>
19 #include <stdlib.h>
20 #include <string.h>
21 #include <unistd.h>
22
23 #include <linux/watchdog.h>
24
25 #include "log.h"
26 #include "util.h"
27
28 #define DEV_NAME "/dev/watchdog"
29
watchdogd_main(int argc,char ** argv)30 int watchdogd_main(int argc, char **argv) {
31 open_devnull_stdio();
32 klog_init();
33 klog_set_level(KLOG_NOTICE_LEVEL);
34
35 int interval = 10;
36 if (argc >= 2) interval = atoi(argv[1]);
37
38 int margin = 10;
39 if (argc >= 3) margin = atoi(argv[2]);
40
41 NOTICE("watchdogd started (interval %d, margin %d)!\n", interval, margin);
42
43 int fd = open(DEV_NAME, O_RDWR|O_CLOEXEC);
44 if (fd == -1) {
45 ERROR("watchdogd: Failed to open %s: %s\n", DEV_NAME, strerror(errno));
46 return 1;
47 }
48
49 int timeout = interval + margin;
50 int ret = ioctl(fd, WDIOC_SETTIMEOUT, &timeout);
51 if (ret) {
52 ERROR("watchdogd: Failed to set timeout to %d: %s\n", timeout, strerror(errno));
53 ret = ioctl(fd, WDIOC_GETTIMEOUT, &timeout);
54 if (ret) {
55 ERROR("watchdogd: Failed to get timeout: %s\n", strerror(errno));
56 } else {
57 if (timeout > margin) {
58 interval = timeout - margin;
59 } else {
60 interval = 1;
61 }
62 ERROR("watchdogd: Adjusted interval to timeout returned by driver: timeout %d, interval %d, margin %d\n",
63 timeout, interval, margin);
64 }
65 }
66
67 while (true) {
68 write(fd, "", 1);
69 sleep(interval);
70 }
71 }
72