gpio.h header

This header is used by parports. For more information, see:

gpio.h contains the following programming interfaces:

IOCTLs

 
IOCTL_GPIO_CONTROLLER_SPECIFIC_FUNCTION

The IOCTL_GPIO_CONTROLLER_SPECIFIC_FUNCTION I/O control code enables a client of the general-purpose I/O (GPIO) controller to request a controller-specific device-control operation.
IOCTL_GPIO_READ_PINS

The IOCTL_GPIO_READ_PINS I/O control code enables a client of the general-purpose I/O (GPIO) controller to read from a set of GPIO pins that are configured as inputs.
IOCTL_GPIO_WRITE_PINS

The IOCTL_GPIO_WRITE_PINS I/O control code enables a client of the general-purpose I/O (GPIO) controller to write to a set of GPIO pins that are configured as outputs.