1/* $Id: ioctl.h,v 1.1.1.1 2008/10/15 03:27:19 james26_jang Exp $ 2 * 3 * linux/ioctl.h for Linux by H.H. Bergman. 4 */ 5 6#ifndef _M68K_IOCTL_H 7#define _M68K_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/* 20 * I don't really have any idea about what this should look like, so 21 * for the time being, this is heavily based on the PC definitions. 22 */ 23 24/* 25 * The following is for compatibility across the various Linux 26 * platforms. The i386 ioctl numbering scheme doesn't really enforce 27 * a type field. De facto, however, the top 8 bits of the lower 16 28 * bits are indeed used as a type field, so we might just as well make 29 * this explicit here. Please be sure to use the decoding macros 30 * below from now on. 31 */ 32#define _IOC_NRBITS 8 33#define _IOC_TYPEBITS 8 34#define _IOC_SIZEBITS 14 35#define _IOC_DIRBITS 2 36 37#define _IOC_NRMASK ((1 << _IOC_NRBITS)-1) 38#define _IOC_TYPEMASK ((1 << _IOC_TYPEBITS)-1) 39#define _IOC_SIZEMASK ((1 << _IOC_SIZEBITS)-1) 40#define _IOC_DIRMASK ((1 << _IOC_DIRBITS)-1) 41 42#define _IOC_NRSHIFT 0 43#define _IOC_TYPESHIFT (_IOC_NRSHIFT+_IOC_NRBITS) 44#define _IOC_SIZESHIFT (_IOC_TYPESHIFT+_IOC_TYPEBITS) 45#define _IOC_DIRSHIFT (_IOC_SIZESHIFT+_IOC_SIZEBITS) 46 47/* 48 * Direction bits. 49 */ 50#define _IOC_NONE 0U 51#define _IOC_WRITE 1U 52#define _IOC_READ 2U 53 54#define _IOC(dir,type,nr,size) \ 55 (((dir) << _IOC_DIRSHIFT) | \ 56 ((type) << _IOC_TYPESHIFT) | \ 57 ((nr) << _IOC_NRSHIFT) | \ 58 ((size) << _IOC_SIZESHIFT)) 59 60/* used to create numbers */ 61#define _IO(type,nr) _IOC(_IOC_NONE,(type),(nr),0) 62#define _IOR(type,nr,size) _IOC(_IOC_READ,(type),(nr),sizeof(size)) 63#define _IOW(type,nr,size) _IOC(_IOC_WRITE,(type),(nr),sizeof(size)) 64#define _IOWR(type,nr,size) _IOC(_IOC_READ|_IOC_WRITE,(type),(nr),sizeof(size)) 65 66/* used to decode ioctl numbers.. */ 67#define _IOC_DIR(nr) (((nr) >> _IOC_DIRSHIFT) & _IOC_DIRMASK) 68#define _IOC_TYPE(nr) (((nr) >> _IOC_TYPESHIFT) & _IOC_TYPEMASK) 69#define _IOC_NR(nr) (((nr) >> _IOC_NRSHIFT) & _IOC_NRMASK) 70#define _IOC_SIZE(nr) (((nr) >> _IOC_SIZESHIFT) & _IOC_SIZEMASK) 71 72/* ...and for the drivers/sound files... */ 73 74#define IOC_IN (_IOC_WRITE << _IOC_DIRSHIFT) 75#define IOC_OUT (_IOC_READ << _IOC_DIRSHIFT) 76#define IOC_INOUT ((_IOC_WRITE|_IOC_READ) << _IOC_DIRSHIFT) 77#define IOCSIZE_MASK (_IOC_SIZEMASK << _IOC_SIZESHIFT) 78#define IOCSIZE_SHIFT (_IOC_SIZESHIFT) 79 80#endif /* _M68K_IOCTL_H */ 81