2 * Copyright (C) 2013 Felix Fietkau <nbd@openwrt.org>
3 * Copyright (C) 2013 John Crispin <blogic@openwrt.org>
5 * This program is free software; you can redistribute it and/or modify
6 * it under the terms of the GNU Lesser General Public License version 2.1
7 * as published by the Free Software Foundation
9 * This program is distributed in the hope that it will be useful,
10 * but WITHOUT ANY WARRANTY; without even the implied warranty of
11 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
12 * GNU General Public License for more details.
15 #include <linux/watchdog.h>
17 #include <sys/ioctl.h>
18 #include <sys/types.h>
24 #include <libubox/uloop.h>
29 #define WDT_PATH "/dev/watchdog"
31 static struct uloop_timeout wdt_timeout;
32 static int wdt_fd = -1;
33 static int wdt_frequency = 5;
35 static void watchdog_timeout_cb(struct uloop_timeout *t)
38 if (write(wdt_fd, "X", 1) < 0)
39 ERROR("WDT failed to write: %s\n", strerror(errno));
40 uloop_timeout_set(t, wdt_frequency * 1000);
43 int watchdog_timeout(int timeout)
49 DEBUG(2, "Set watchdog timeout: %ds\n", timeout);
50 ioctl(wdt_fd, WDIOC_SETTIMEOUT, &timeout);
52 ioctl(wdt_fd, WDIOC_GETTIMEOUT, &timeout);
57 int watchdog_frequency(int frequency)
63 DEBUG(2, "Set watchdog frequency: %ds\n", frequency);
64 wdt_frequency = frequency;
70 char* watchdog_fd(void)
72 static char fd_buf[3];
76 snprintf(fd_buf, sizeof(fd_buf), "%d", wdt_fd);
81 void watchdog_init(void)
83 char *env = getenv("WDTFD");
85 wdt_timeout.cb = watchdog_timeout_cb;
87 LOG("- watchdog -\n");
88 DEBUG(1, "Watchdog handover: fd=%s\n", env);
90 fcntl(wdt_fd, F_SETFD, fcntl(wdt_fd, F_GETFD) | FD_CLOEXEC);
93 wdt_fd = open("/dev/watchdog", O_WRONLY);
95 fcntl(wdt_fd, F_SETFD, fcntl(wdt_fd, F_GETFD) | FD_CLOEXEC);
100 watchdog_timeout_cb(&wdt_timeout);
102 DEBUG(2, "Opened watchdog with timeout %ds\n", watchdog_timeout(0));