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