include/asm-nios2nommu/ioctl.h

   1 /* $Id: ioctl.h,v 1.1 2006/07/05 06:20:25 gerg Exp $
   2  *
   3  * linux/ioctl.h for Linux by H.H. Bergman.
   4  *
   5  * Copyright (C) 2004,  Microtronix Datacom Ltd.
   6  *
   7  * All rights reserved.
   8  *
   9  * This program is free software; you can redistribute it and/or modify
  10  * it under the terms of the GNU General Public License as published by
  11  * the Free Software Foundation; either version 2 of the License, or
  12  * (at your option) any later version.
  13  *
  14  * This program is distributed in the hope that it will be useful, but
  15  * WITHOUT ANY WARRANTY; without even the implied warranty of
  16  * MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE, GOOD TITLE or
  17  * NON INFRINGEMENT.  See the GNU General Public License for more
  18  * details.
  19  *
  20  * You should have received a copy of the GNU General Public License
  21  * along with this program; if not, write to the Free Software
  22  * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
  23  *
  24  */
  25
  26 #ifndef _NIOS2_IOCTL_H
  27 #define _NIOS2_IOCTL_H
  28
  29 /* ioctl command encoding: 32 bits total, command in lower 16 bits,
  30  * size of the parameter structure in the lower 14 bits of the
  31  * upper 16 bits.
  32  * Encoding the size of the parameter structure in the ioctl request
  33  * is useful for catching programs compiled with old versions
  34  * and to avoid overwriting user space outside the user buffer area.
  35  * The highest 2 bits are reserved for indicating the ``access mode''.
  36  * NOTE: This limits the max parameter size to 16kB -1 !
  37  */
  38
  39 /*
  40  * I don't really have any idea about what this should look like, so
  41  * for the time being, this is heavily based on the PC definitions.
  42  */
  43
  44 /*
  45  * The following is for compatibility across the various Linux
  46  * platforms.  The i386 ioctl numbering scheme doesn't really enforce
  47  * a type field.  De facto, however, the top 8 bits of the lower 16
  48  * bits are indeed used as a type field, so we might just as well make
  49  * this explicit here.  Please be sure to use the decoding macros
  50  * below from now on.
  51  */
  52 #define _IOC_NRBITS     8
  53 #define _IOC_TYPEBITS   8
  54 #define _IOC_SIZEBITS   14
  55 #define _IOC_DIRBITS    2
  56
  57 #define _IOC_NRMASK     ((1 << _IOC_NRBITS)-1)
  58 #define _IOC_TYPEMASK   ((1 << _IOC_TYPEBITS)-1)
  59 #define _IOC_SIZEMASK   ((1 << _IOC_SIZEBITS)-1)
  60 #define _IOC_DIRMASK    ((1 << _IOC_DIRBITS)-1)
  61
  62 #define _IOC_NRSHIFT    0
  63 #define _IOC_TYPESHIFT  (_IOC_NRSHIFT+_IOC_NRBITS)
  64 #define _IOC_SIZESHIFT  (_IOC_TYPESHIFT+_IOC_TYPEBITS)
  65 #define _IOC_DIRSHIFT   (_IOC_SIZESHIFT+_IOC_SIZEBITS)
  66
  67 /*
  68  * Direction bits.
  69  */
  70 #define _IOC_NONE       0U
  71 #define _IOC_WRITE      1U
  72 #define _IOC_READ       2U
  73
  74 #define _IOC(dir,type,nr,size) \
  75         (((dir)  << _IOC_DIRSHIFT) | \
  76          ((type) << _IOC_TYPESHIFT) | \
  77          ((nr)   << _IOC_NRSHIFT) | \
  78          ((size) << _IOC_SIZESHIFT))
  79
  80 /* used to create numbers */
  81 #define _IO(type,nr)            _IOC(_IOC_NONE,(type),(nr),0)
  82 #define _IOR(type,nr,size)      _IOC(_IOC_READ,(type),(nr),sizeof(size))
  83 #define _IOW(type,nr,size)      _IOC(_IOC_WRITE,(type),(nr),sizeof(size))
  84 #define _IOWR(type,nr,size)     _IOC(_IOC_READ|_IOC_WRITE,(type),(nr),sizeof(size))
  85
  86 /* used to decode ioctl numbers.. */
  87 #define _IOC_DIR(nr)            (((nr) >> _IOC_DIRSHIFT) & _IOC_DIRMASK)
  88 #define _IOC_TYPE(nr)           (((nr) >> _IOC_TYPESHIFT) & _IOC_TYPEMASK)
  89 #define _IOC_NR(nr)             (((nr) >> _IOC_NRSHIFT) & _IOC_NRMASK)
  90 #define _IOC_SIZE(nr)           (((nr) >> _IOC_SIZESHIFT) & _IOC_SIZEMASK)
  91
  92 /* ...and for the drivers/sound files... */
  93
  94 #define IOC_IN          (_IOC_WRITE << _IOC_DIRSHIFT)
  95 #define IOC_OUT         (_IOC_READ << _IOC_DIRSHIFT)
  96 #define IOC_INOUT       ((_IOC_WRITE|_IOC_READ) << _IOC_DIRSHIFT)
  97 #define IOCSIZE_MASK    (_IOC_SIZEMASK << _IOC_SIZESHIFT)
  98 #define IOCSIZE_SHIFT   (_IOC_SIZESHIFT)
  99
 100 #endif /* _NIOS2_IOCTL_H */