Commit 56fb9e53 authored by Randy Dunlap's avatar Randy Dunlap Committed by Wim Van Sebroeck

[WATCHDOG] Documentation/watchdog update

Documentation/watchdog/:
Expose example and tool source files in the Documentation/ directory in
their own files instead of being buried (almost hidden) in readme/txt files.

This will make them more visible/usable to users who may need
to use them, to developers who may need to test with them, and
to janitors who would update them if they were more visible.

Also, if any of these possibly should not be in the kernel tree at
all, it will be clearer that they are here and we can discuss if
they should be removed.
Signed-off-by: default avatarRandy Dunlap <rdunlap@xenotime.net>
Signed-off-by: default avatarWim Van Sebroeck <wim@iguana.be>
Signed-off-by: default avatarAndrew Morton <akpm@osdl.org>
parent dfc7bd9c
......@@ -22,78 +22,9 @@
to run the program with an "&" to run it in the background!)
If you want to write a program to be compatible with the PC Watchdog
driver, simply do the following:
-- Snippet of code --
/*
* Watchdog Driver Test Program
*/
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include <fcntl.h>
#include <sys/ioctl.h>
#include <linux/types.h>
#include <linux/watchdog.h>
int fd;
/*
* This function simply sends an IOCTL to the driver, which in turn ticks
* the PC Watchdog card to reset its internal timer so it doesn't trigger
* a computer reset.
*/
void keep_alive(void)
{
int dummy;
ioctl(fd, WDIOC_KEEPALIVE, &dummy);
}
/*
* The main program. Run the program with "-d" to disable the card,
* or "-e" to enable the card.
*/
int main(int argc, char *argv[])
{
fd = open("/dev/watchdog", O_WRONLY);
if (fd == -1) {
fprintf(stderr, "Watchdog device not enabled.\n");
fflush(stderr);
exit(-1);
}
if (argc > 1) {
if (!strncasecmp(argv[1], "-d", 2)) {
ioctl(fd, WDIOC_SETOPTIONS, WDIOS_DISABLECARD);
fprintf(stderr, "Watchdog card disabled.\n");
fflush(stderr);
exit(0);
} else if (!strncasecmp(argv[1], "-e", 2)) {
ioctl(fd, WDIOC_SETOPTIONS, WDIOS_ENABLECARD);
fprintf(stderr, "Watchdog card enabled.\n");
fflush(stderr);
exit(0);
} else {
fprintf(stderr, "-d to disable, -e to enable.\n");
fprintf(stderr, "run by itself to tick the card.\n");
fflush(stderr);
exit(0);
}
} else {
fprintf(stderr, "Watchdog Ticking Away!\n");
fflush(stderr);
}
while(1) {
keep_alive();
sleep(1);
}
}
-- End snippet --
driver, simply use of modify the watchdog test program:
Documentation/watchdog/src/watchdog-test.c
Other IOCTL functions include:
......
#include <stdlib.h>
#include <fcntl.h>
int main(int argc, const char *argv[]) {
int fd = open("/dev/watchdog", O_WRONLY);
if (fd == -1) {
perror("watchdog");
exit(1);
}
while (1) {
write(fd, "\0", 1);
fsync(fd);
sleep(10);
}
}
/*
* Watchdog Driver Test Program
*/
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include <fcntl.h>
#include <sys/ioctl.h>
#include <linux/types.h>
#include <linux/watchdog.h>
int fd;
/*
* This function simply sends an IOCTL to the driver, which in turn ticks
* the PC Watchdog card to reset its internal timer so it doesn't trigger
* a computer reset.
*/
void keep_alive(void)
{
int dummy;
ioctl(fd, WDIOC_KEEPALIVE, &dummy);
}
/*
* The main program. Run the program with "-d" to disable the card,
* or "-e" to enable the card.
*/
int main(int argc, char *argv[])
{
fd = open("/dev/watchdog", O_WRONLY);
if (fd == -1) {
fprintf(stderr, "Watchdog device not enabled.\n");
fflush(stderr);
exit(-1);
}
if (argc > 1) {
if (!strncasecmp(argv[1], "-d", 2)) {
ioctl(fd, WDIOC_SETOPTIONS, WDIOS_DISABLECARD);
fprintf(stderr, "Watchdog card disabled.\n");
fflush(stderr);
exit(0);
} else if (!strncasecmp(argv[1], "-e", 2)) {
ioctl(fd, WDIOC_SETOPTIONS, WDIOS_ENABLECARD);
fprintf(stderr, "Watchdog card enabled.\n");
fflush(stderr);
exit(0);
} else {
fprintf(stderr, "-d to disable, -e to enable.\n");
fprintf(stderr, "run by itself to tick the card.\n");
fflush(stderr);
exit(0);
}
} else {
fprintf(stderr, "Watchdog Ticking Away!\n");
fflush(stderr);
}
while(1) {
keep_alive();
sleep(1);
}
}
......@@ -34,22 +34,7 @@ activates as soon as /dev/watchdog is opened and will reboot unless
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:
#include <stdlib.h>
#include <fcntl.h>
int main(int argc, const char *argv[]) {
int fd=open("/dev/watchdog",O_WRONLY);
if (fd==-1) {
perror("watchdog");
exit(1);
}
while(1) {
write(fd, "\0", 1);
sleep(10);
}
}
like this source file: see Documentation/watchdog/src/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.
......
......@@ -65,28 +65,7 @@ The external event interfaces on the WDT boards are not currently supported.
Minor numbers are however allocated for it.
Example Watchdog Driver
-----------------------
#include <stdio.h>
#include <unistd.h>
#include <fcntl.h>
int main(int argc, const char *argv[])
{
int fd=open("/dev/watchdog",O_WRONLY);
if(fd==-1)
{
perror("watchdog");
exit(1);
}
while(1)
{
write(fd,"\0",1);
fsync(fd);
sleep(10);
}
}
Example Watchdog Driver: see Documentation/watchdog/src/watchdog-simple.c
Contact Information
......
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