NAME
gpio_set_ctl — set control lines on GPIO card
SYNOPSIS
#include <dvio.h>
int gpio_set_ctl(int eid, int value);
DESCRIPTION
gpio_set_ctl()
sets the control register of a
GPIO
interface.
eid
is an entity identifier of an open
GPIO
device file obtained from an
open(),
dup(),
fcntl(),
or
creat()
call (see
open(2),
dup(2),
fcntl(2),
and
creat(2)).
value
is the value to be written into the control register of the
GPIO
interface associated with
eid.
value
is mapped onto the control lines on the interface card,
with the least significant bit mapped to
CTL0.
Only the
x
least significant bits are used, where
x
is the number of control lines available
on the hardware interface being used.
DEPENDENCIES
Series 800
For the HP27114A,
x
is 3.
For the HP27114B,
x
is 6.
For the HP28651A,
x
is 5.
RETURN VALUE
gpio_set_ctl()
returns 0 if successful and -1 if an error was encountered.
ERRORS
gpio_set_ctl()
fails if any of the following conditions are encountered, and sets
errno
accordingly:
- [EBADF]
eid
does not refer to an open file.
- [ENOTTY]
eid
does not refer to a
GPIO
device file.
