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 <linux/watchdog.h>
20 #include <stdlib.h>
21 #include <string.h>
22 #include <unistd.h>
23
24 #include <android-base/logging.h>
25
26 #define DEV_NAME "/dev/watchdog"
27
main(int argc,char ** argv)28 int main(int argc, char** argv) {
29 android::base::InitLogging(argv, &android::base::KernelLogger);
30
31 int interval = 10;
32 if (argc >= 2) interval = atoi(argv[1]);
33
34 int margin = 10;
35 if (argc >= 3) margin = atoi(argv[2]);
36
37 LOG(INFO) << "watchdogd started (interval " << interval << ", margin " << margin << ")!";
38
39 int fd = open(DEV_NAME, O_RDWR | O_CLOEXEC);
40 if (fd == -1) {
41 PLOG(ERROR) << "Failed to open " << DEV_NAME;
42 return 1;
43 }
44
45 int timeout = interval + margin;
46 int ret = ioctl(fd, WDIOC_SETTIMEOUT, &timeout);
47 if (ret) {
48 PLOG(ERROR) << "Failed to set timeout to " << timeout;
49 ret = ioctl(fd, WDIOC_GETTIMEOUT, &timeout);
50 if (ret) {
51 PLOG(ERROR) << "Failed to get timeout";
52 } else {
53 if (timeout > margin) {
54 interval = timeout - margin;
55 } else {
56 interval = 1;
57 }
58 LOG(WARNING) << "Adjusted interval to timeout returned by driver: "
59 << "timeout " << timeout << ", interval " << interval << ", margin "
60 << margin;
61 }
62 }
63
64 while (true) {
65 write(fd, "", 1);
66 sleep(interval);
67 }
68 }
69