ioctl_linux.go

// +build linux

package joystick

import (
	"golang.org/x/sys/unix"
	"os"
	"syscall"
	"unsafe"
)

const (
	_IOC_NRBITS   = 8
	_IOC_TYPEBITS = 8
	_IOC_SIZEBITS = 14
	_IOC_DIRBITS  = 2

	_IOC_NRMASK   = ((1 << _IOC_NRBITS) - 1)
	_IOC_TYPEMASK = ((1 << _IOC_TYPEBITS) - 1)
	_IOC_SIZEMASK = ((1 << _IOC_SIZEBITS) - 1)
	_IOC_DIRMASK  = ((1 << _IOC_DIRBITS) - 1)

	_IOC_NRSHIFT   = 0
	_IOC_TYPESHIFT = (_IOC_NRSHIFT + _IOC_NRBITS)
	_IOC_SIZESHIFT = (_IOC_TYPESHIFT + _IOC_TYPEBITS)
	_IOC_DIRSHIFT  = (_IOC_SIZESHIFT + _IOC_SIZEBITS)

	_IOC_NONE  = 0
	_IOC_WRITE = 1
	_IOC_READ  = 2
)

func _IOC(dir int, t int, nr int, size int) int {
	return (dir << _IOC_DIRSHIFT) | (t << _IOC_TYPESHIFT) | (nr << _IOC_NRSHIFT) | (size << _IOC_SIZESHIFT)
}

func _IOR(t int, nr int, size int) int {
	return _IOC(_IOC_READ, t, nr, size)
}

func _IOW(t int, nr int, size int) int {
	return _IOC(_IOC_WRITE, t, nr, size)
}

func ioctl(f *os.File, req int, ptr unsafe.Pointer) syscall.Errno {
	_, _, err := unix.Syscall(unix.SYS_IOCTL, uintptr(f.Fd()), uintptr(req), uintptr(ptr))
	return err
}