Based on kernel version 4.8. Page generated on 2016-10-06 23:19 EST.
1 /* 2 * Watchdog Driver Test Program 3 */ 4 5 #include <errno.h> 6 #include <stdio.h> 7 #include <stdlib.h> 8 #include <string.h> 9 #include <unistd.h> 10 #include <fcntl.h> 11 #include <signal.h> 12 #include <sys/ioctl.h> 13 #include <linux/types.h> 14 #include <linux/watchdog.h> 15 16 int fd; 17 const char v = 'V'; 18 19 /* 20 * This function simply sends an IOCTL to the driver, which in turn ticks 21 * the PC Watchdog card to reset its internal timer so it doesn't trigger 22 * a computer reset. 23 */ 24 static void keep_alive(void) 25 { 26 int dummy; 27 28 printf("."); 29 ioctl(fd, WDIOC_KEEPALIVE, &dummy); 30 } 31 32 /* 33 * The main program. Run the program with "-d" to disable the card, 34 * or "-e" to enable the card. 35 */ 36 37 static void term(int sig) 38 { 39 int ret = write(fd, &v, 1); 40 41 close(fd); 42 if (ret < 0) 43 printf("\nStopping watchdog ticks failed (%d)...\n", errno); 44 else 45 printf("\nStopping watchdog ticks...\n"); 46 exit(0); 47 } 48 49 int main(int argc, char *argv[]) 50 { 51 int flags; 52 unsigned int ping_rate = 1; 53 int ret; 54 55 setbuf(stdout, NULL); 56 57 fd = open("/dev/watchdog", O_WRONLY); 58 59 if (fd == -1) { 60 printf("Watchdog device not enabled.\n"); 61 exit(-1); 62 } 63 64 if (argc > 1) { 65 if (!strncasecmp(argv[1], "-d", 2)) { 66 flags = WDIOS_DISABLECARD; 67 ioctl(fd, WDIOC_SETOPTIONS, &flags); 68 printf("Watchdog card disabled.\n"); 69 goto end; 70 } else if (!strncasecmp(argv[1], "-e", 2)) { 71 flags = WDIOS_ENABLECARD; 72 ioctl(fd, WDIOC_SETOPTIONS, &flags); 73 printf("Watchdog card enabled.\n"); 74 goto end; 75 } else if (!strncasecmp(argv[1], "-t", 2) && argv[2]) { 76 flags = atoi(argv[2]); 77 ioctl(fd, WDIOC_SETTIMEOUT, &flags); 78 printf("Watchdog timeout set to %u seconds.\n", flags); 79 goto end; 80 } else if (!strncasecmp(argv[1], "-p", 2) && argv[2]) { 81 ping_rate = strtoul(argv[2], NULL, 0); 82 printf("Watchdog ping rate set to %u seconds.\n", ping_rate); 83 } else { 84 printf("-d to disable, -e to enable, -t <n> to set " \ 85 "the timeout,\n-p <n> to set the ping rate, and \n"); 86 printf("run by itself to tick the card.\n"); 87 goto end; 88 } 89 } 90 91 printf("Watchdog Ticking Away!\n"); 92 93 signal(SIGINT, term); 94 95 while(1) { 96 keep_alive(); 97 sleep(ping_rate); 98 } 99 end: 100 ret = write(fd, &v, 1); 101 if (ret < 0) 102 printf("Stopping watchdog ticks failed (%d)...\n", errno); 103 close(fd); 104 return 0; 105 }