1 /*
2 * linux/ioctl.h for Linux by H.H. Bergman.
3 */
4
5 #ifndef _ASMARM_IOCTL_H
6 #define _ASMARM_IOCTL_H
7
8 /* ioctl command encoding: 32 bits total, command in lower 16 bits,
9 * size of the parameter structure in the lower 14 bits of the
10 * upper 16 bits.
11 * Encoding the size of the parameter structure in the ioctl request
12 * is useful for catching programs compiled with old versions
13 * and to avoid overwriting user space outside the user buffer area.
14 * The highest 2 bits are reserved for indicating the ``access mode''.
15 * NOTE: This limits the max parameter size to 16kB -1 !
16 */
17
18 /*
19 * The following is for compatibility across the various Linux
20 * platforms. The i386 ioctl numbering scheme doesn't really enforce
21 * a type field. De facto, however, the top 8 bits of the lower 16
22 * bits are indeed used as a type field, so we might just as well make
23 * this explicit here. Please be sure to use the decoding macros
24 * below from now on.
25 */
26 #define _IOC_NRBITS 8
27 #define _IOC_TYPEBITS 8
28 #define _IOC_SIZEBITS 14
29 #define _IOC_DIRBITS 2
30
31 #define _IOC_NRMASK ((1 << _IOC_NRBITS)-1)
32 #define _IOC_TYPEMASK ((1 << _IOC_TYPEBITS)-1)
33 #define _IOC_SIZEMASK ((1 << _IOC_SIZEBITS)-1)
34 #define _IOC_DIRMASK ((1 << _IOC_DIRBITS)-1)
35
36 #define _IOC_NRSHIFT 0
37 #define _IOC_TYPESHIFT (_IOC_NRSHIFT+_IOC_NRBITS)
38 #define _IOC_SIZESHIFT (_IOC_TYPESHIFT+_IOC_TYPEBITS)
39 #define _IOC_DIRSHIFT (_IOC_SIZESHIFT+_IOC_SIZEBITS)
40
41 /*
42 * Direction bits.
43 */
44 #define _IOC_NONE 0U
45 #define _IOC_WRITE 1U
46 #define _IOC_READ 2U
47
48 #define _IOC(dir,type,nr,size) \
49 (((dir) << _IOC_DIRSHIFT) | \
50 ((type) << _IOC_TYPESHIFT) | \
51 ((nr) << _IOC_NRSHIFT) | \
52 ((size) << _IOC_SIZESHIFT))
53
54 /* used to create numbers */
55 #define _IO(type,nr) _IOC(_IOC_NONE,(type),(nr),0)
56 #define _IOR(type,nr,size) _IOC(_IOC_READ,(type),(nr),sizeof(size))
57 #define _IOW(type,nr,size) _IOC(_IOC_WRITE,(type),(nr),sizeof(size))
58 #define _IOWR(type,nr,size) _IOC(_IOC_READ|_IOC_WRITE,(type),(nr),sizeof(size))
59
60 /* used to decode ioctl numbers.. */
61 #define _IOC_DIR(nr) (((nr) >> _IOC_DIRSHIFT) & _IOC_DIRMASK)
62 #define _IOC_TYPE(nr) (((nr) >> _IOC_TYPESHIFT) & _IOC_TYPEMASK)
63 #define _IOC_NR(nr) (((nr) >> _IOC_NRSHIFT) & _IOC_NRMASK)
64 #define _IOC_SIZE(nr) (((nr) >> _IOC_SIZESHIFT) & _IOC_SIZEMASK)
65
66 /* ...and for the drivers/sound files... */
67
68 #define IOC_IN (_IOC_WRITE << _IOC_DIRSHIFT)
69 #define IOC_OUT (_IOC_READ << _IOC_DIRSHIFT)
70 #define IOC_INOUT ((_IOC_WRITE|_IOC_READ) << _IOC_DIRSHIFT)
71 #define IOCSIZE_MASK (_IOC_SIZEMASK << _IOC_SIZESHIFT)
72 #define IOCSIZE_SHIFT (_IOC_SIZESHIFT)
73
74 #endif /* _ASMARM_IOCTL_H */
75
This page was automatically generated by the
LXR engine.
Visit the LXR main site for more
information.