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.TH libwatchdog 2 "21 December 2018" "version 1" "Linux Simple I/O Library"
.SH NAME
.B libwatchdog
\-\- Linux Simple I/O Library: Watchdog Timer Module
.SH SYNOPSIS
.nf
.B #include <libsimpleio/libwatchdog.h>

.BI "void WATCHDOG_open(const char *" name ", int32_t *" fd ", int32_t *" error ");"

.BI "void WATCHDOG_close(int32_t " fd ", int32_t *" error ");"

.BI "void WATCHDOG_get_timeout(int32_t " fd ", int32_t *" timeout ", int32_t *" error ");"

.BI "void WATCHDOG_set_timeout(int32_t " fd ", int32_t " newtimeout ","
.BI "   int32_t *" timeout ", int32_t *" error ");"

.BI "void WATCHDOG_kick(int32_t " fd ", int32_t *" error ");"

.fi
Link with
.BR -lsimpleio .
.SH DESCRIPTION
.nh
All functions return either
.B 0
(upon success) or an
.B errno
value (upon failure) in
.IR *error .
.PP
.B WATCHDOG_open()
opens a watchdog timer device.  The device node name, usually
.BR /dev/watchdog ,
must be passed in the
.IR name
parameter. Upon success, a file descriptor for the
watchdog timer device is returned in
.IR *fd .
.PP
.B WATCHDOG_close()
closes a previously opened watchdog timer device.  Note that this may result in
watchdog timer expiration and subsequent system reset.
.PP
.B WATCHDOG_get_timeout()
may be used to discover the current watchdog timeout period.
Upon success, the watchdog period in seconds will be returned in
.IR *timeout .
.PP
.B WATCHDOG_set_timeout()
may be used to change the watchdog timeout period. The requested new
timeout period in seconds must be passed in
.IR newtimeout .
Upon success, the actual new watchdog period in seconds will be returned in
.IR *timeout .
Note that the new watchdog period may be different from that requested.
For example, if the watchdog timer device has a granularity of one minute,
requesting a timeout of 45 seconds will result in an actual timeout of 60 seconds.
Also note that the particular watchdog timer device may not allow increasing the
timeout or may not allow changing it at all.
.PP
.B WATCHDOG_kick()
may be used to reset the watchdog timer.
.SH SEE ALSO
.BR libsimpleio "(2), " libadc "(2), " libdac "(2), " libevent "(2), " libgpio "(2),"
.br
.BR libhidraw "(2), " libi2c "(2), " libipv4 "(2), " liblinux "(2), " liblinx "(2),"
.br
.BR libpwm "(2), " libserial "(2), " libspi "(2), " libstream "(2)"
.SH AUTHOR
Philip Munts dba Munts Technologies.