First implementation

vendor/periph.io/x/periph/host/fs/ioctl.go

@@ -0,0 +1,51 @@
+// Copyright 2019 The Periph Authors. All rights reserved.
+// Use of this source code is governed under the Apache License, Version 2.0
+// that can be found in the LICENSE file.
+
+package fs
+
+// These constants, variables and functions are ported from the Linux userland
+// API header ioctl.h (commonly packaged at /usr/include/linux/ioctl.h which
+// includes /usr/include/asm-generic/ioctl.h).
+
+const (
+	iocNrbits   uint = 8
+	iocTypebits uint = 8
+
+	iocNrshift uint = 0
+
+	iocTypeshift = iocNrshift + iocNrbits
+	iocSizeshift = iocTypeshift + iocTypebits
+	iocDirshift  = iocSizeshift + iocSizebits
+)
+
+func ioc(dir, typ, nr, size uint) uint {
+	return (dir << iocDirshift) |
+		(typ << iocTypeshift) |
+		(nr << iocNrshift) |
+		(size << iocSizeshift)
+}
+
+// IO defines an ioctl with no parameters. It corresponds to _IO in the Linux
+// userland API.
+func IO(typ, nr uint) uint {
+	return ioc(iocNone, typ, nr, 0)
+}
+
+// IOR defines an ioctl with read (userland perspective) parameters. It
+// corresponds to _IOR in the Linux userland API.
+func IOR(typ, nr, size uint) uint {
+	return ioc(iocRead, typ, nr, size)
+}
+
+// IOW defines an ioctl with write (userland perspective) parameters. It
+// corresponds to _IOW in the Linux userland API.
+func IOW(typ, nr, size uint) uint {
+	return ioc(iocWrite, typ, nr, size)
+}
+
+// IOWR defines an ioctl with both read and write parameters. It corresponds to
+// _IOWR in the Linux userland API.
+func IOWR(typ, nr, size uint) uint {
+	return ioc(iocRead|iocWrite, typ, nr, size)
+}