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
22#include <linux/watchdog.h>
23
24#include "log.h"
25#include "util.h"
26
27#define DEV_NAME "/dev/watchdog"
28
29int watchdogd_main(int argc, char **argv)
30{
31    int fd;
32    int ret;
33    int interval = 10;
34    int margin = 10;
35    int timeout;
36
37    open_devnull_stdio();
38    klog_init();
39
40    INFO("Starting watchdogd\n");
41
42    if (argc >= 2)
43        interval = atoi(argv[1]);
44
45    if (argc >= 3)
46        margin = atoi(argv[2]);
47
48    timeout = interval + margin;
49
50    fd = open(DEV_NAME, O_RDWR);
51    if (fd < 0) {
52        ERROR("watchdogd: Failed to open %s: %s\n", DEV_NAME, strerror(errno));
53        return 1;
54    }
55
56    ret = ioctl(fd, WDIOC_SETTIMEOUT, &timeout);
57    if (ret) {
58        ERROR("watchdogd: Failed to set timeout to %d: %s\n", timeout, strerror(errno));
59        ret = ioctl(fd, WDIOC_GETTIMEOUT, &timeout);
60        if (ret) {
61            ERROR("watchdogd: Failed to get timeout: %s\n", strerror(errno));
62        } else {
63            if (timeout > margin)
64                interval = timeout - margin;
65            else
66                interval = 1;
67            ERROR("watchdogd: Adjusted interval to timeout returned by driver: timeout %d, interval %d, margin %d\n",
68                  timeout, interval, margin);
69        }
70    }
71
72    while(1) {
73        write(fd, "", 1);
74        sleep(interval);
75    }
76}
77
78