1/* $Id: ioctl.h,v 1.1.1.1 2008/10/15 03:27:22 james26_jang Exp $
2 *
3 * linux/ioctl.h for Linux by H.H. Bergman.
4 */
5
6#ifndef _ASM_PARISC_IOCTL_H
7#define _ASM_PARISC_IOCTL_H
8
9/* ioctl command encoding: 32 bits total, command in lower 16 bits,
10 * size of the parameter structure in the lower 14 bits of the
11 * upper 16 bits.
12 * Encoding the size of the parameter structure in the ioctl request
13 * is useful for catching programs compiled with old versions
14 * and to avoid overwriting user space outside the user buffer area.
15 * The highest 2 bits are reserved for indicating the ``access mode''.
16 * NOTE: This limits the max parameter size to 16kB -1 !
17 */
18
19#define _IOC_NRBITS	8
20#define _IOC_TYPEBITS	8
21#define _IOC_SIZEBITS	14
22#define _IOC_DIRBITS	2
23
24#define _IOC_NRMASK	((1 << _IOC_NRBITS)-1)
25#define _IOC_TYPEMASK	((1 << _IOC_TYPEBITS)-1)
26#define _IOC_SIZEMASK	((1 << _IOC_SIZEBITS)-1)
27#define _IOC_DIRMASK	((1 << _IOC_DIRBITS)-1)
28
29#define _IOC_NRSHIFT	0
30#define _IOC_TYPESHIFT	(_IOC_NRSHIFT+_IOC_NRBITS)
31#define _IOC_SIZESHIFT	(_IOC_TYPESHIFT+_IOC_TYPEBITS)
32#define _IOC_DIRSHIFT	(_IOC_SIZESHIFT+_IOC_SIZEBITS)
33
34/*
35 * Direction bits.
36 */
37#define _IOC_NONE	0U
38#define _IOC_WRITE	2U
39#define _IOC_READ	1U
40
41#define _IOC(dir,type,nr,size) \
42	(((dir)  << _IOC_DIRSHIFT) | \
43	 ((type) << _IOC_TYPESHIFT) | \
44	 ((nr)   << _IOC_NRSHIFT) | \
45	 ((size) << _IOC_SIZESHIFT))
46
47/* used to create numbers */
48#define _IO(type,nr)		_IOC(_IOC_NONE,(type),(nr),0)
49#define _IOR(type,nr,size)	_IOC(_IOC_READ,(type),(nr),sizeof(size))
50#define _IOW(type,nr,size)	_IOC(_IOC_WRITE,(type),(nr),sizeof(size))
51#define _IOWR(type,nr,size)	_IOC(_IOC_READ|_IOC_WRITE,(type),(nr),sizeof(size))
52
53/* used to decode ioctl numbers.. */
54#define _IOC_DIR(nr)		(((nr) >> _IOC_DIRSHIFT) & _IOC_DIRMASK)
55#define _IOC_TYPE(nr)		(((nr) >> _IOC_TYPESHIFT) & _IOC_TYPEMASK)
56#define _IOC_NR(nr)		(((nr) >> _IOC_NRSHIFT) & _IOC_NRMASK)
57#define _IOC_SIZE(nr)		(((nr) >> _IOC_SIZESHIFT) & _IOC_SIZEMASK)
58
59/* ...and for the drivers/sound files... */
60
61#define IOC_IN		(_IOC_WRITE << _IOC_DIRSHIFT)
62#define IOC_OUT		(_IOC_READ << _IOC_DIRSHIFT)
63#define IOC_INOUT	((_IOC_WRITE|_IOC_READ) << _IOC_DIRSHIFT)
64#define IOCSIZE_MASK	(_IOC_SIZEMASK << _IOC_SIZESHIFT)
65#define IOCSIZE_SHIFT	(_IOC_SIZESHIFT)
66
67#endif /* _ASM_PARISC_IOCTL_H */
68