NAME

gpio_set_ctl − set control lines on GPIO card

SYNOPSIS

int gpio_set_ctl (eid, value)
int eid, value;

HP-UX COMPATIBILITY

Level: Device I/O Library − HP-UX/EXTENDED

Origin: HP

DESCRIPTION

Gpio_set_ctl enables you to set the control register of a GPIO interface.  Eid is an entity identifier of an open GPIO device file obtained from an open(2), dup(2), fcntl(2), or creat(2) call.  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. 

HARDWARE DEPENDENCIES

Series 500:
For the current GPIO card, x is 2. 

RETURN VALUE

Gpio_set_ctl returns 0 if successful, and −1 if an error was encountered. 

DIAGNOSTICS

Gpio_set_ctl fails under the following circumstances, and sets errno (see errno(2)) to the value in square brackets:

eid does not refer to an open file [EBADF];

eid does not refer to a GPIO device file [ENOTTY]. 

Hewlett-Packard  —  last mod. May 11, 2021