subdir-y := accounting auxdisplay blackfin \
- laptops pcmcia watchdog
+ laptops pcmcia
+++ /dev/null
-subdir-y := src
+++ /dev/null
-watchdog-simple
+++ /dev/null
-# List of programs to build
-hostprogs-y := watchdog-simple
-
-# Tell kbuild to always build the programs
-always := $(hostprogs-y)
+++ /dev/null
-#include <stdio.h>
-#include <stdlib.h>
-#include <unistd.h>
-#include <fcntl.h>
-
-int main(void)
-{
- int fd = open("/dev/watchdog", O_WRONLY);
- int ret = 0;
- if (fd == -1) {
- perror("watchdog");
- exit(EXIT_FAILURE);
- }
- while (1) {
- ret = write(fd, "\0", 1);
- if (ret != 1) {
- ret = -1;
- break;
- }
- sleep(10);
- }
- close(fd);
- return ret;
-}
the watchdog is pinged within a certain time, this time is called the
timeout or margin. The simplest way to ping the watchdog is to write
some data to the device. So a very simple watchdog daemon would look
-like this source file: see Documentation/watchdog/src/watchdog-simple.c
+like this source file: see samples/watchdog/watchdog-simple.c
A more advanced driver could for example check that a HTTP server is
still responding before doing the write call to ping the watchdog.
Minor numbers are however allocated for it.
-Example Watchdog Driver: see Documentation/watchdog/src/watchdog-simple.c
+Example Watchdog Driver: see samples/watchdog/watchdog-simple.c
--- /dev/null
+watchdog-simple
--- /dev/null
+CC := $(CROSS_COMPILE)gcc
+PROGS := watchdog-simple
+
+all: $(PROGS)
+
+clean:
+ rm -fr $(PROGS)
+
--- /dev/null
+#include <stdio.h>
+#include <stdlib.h>
+#include <unistd.h>
+#include <fcntl.h>
+
+int main(void)
+{
+ int fd = open("/dev/watchdog", O_WRONLY);
+ int ret = 0;
+ if (fd == -1) {
+ perror("watchdog");
+ exit(EXIT_FAILURE);
+ }
+ while (1) {
+ ret = write(fd, "\0", 1);
+ if (ret != 1) {
+ ret = -1;
+ break;
+ }
+ sleep(10);
+ }
+ close(fd);
+ return ret;
+}