ioctl.h

《嵌入式系统设计与实例开发实验教材二源码》Linux内核移植与编译实验

/*
 * BK Id: SCCS/s.ioctl.h 1.5 05/17/01 18:14:24 cort
 */
#ifndef _PPC_IOCTL_H
#define _PPC_IOCTL_H


/*
 * this was copied from the alpha as it's a bit cleaner there.
 *                         -- Cort
 */

#define _IOC_NRBITS	8
#define _IOC_TYPEBITS	8
#define _IOC_SIZEBITS	13
#define _IOC_DIRBITS	3

#define _IOC_NRMASK	((1 << _IOC_NRBITS)-1)
#define _IOC_TYPEMASK	((1 << _IOC_TYPEBITS)-1)
#define _IOC_SIZEMASK	((1 << _IOC_SIZEBITS)-1)
#define _IOC_DIRMASK	((1 << _IOC_DIRBITS)-1)

#define _IOC_NRSHIFT	0
#define _IOC_TYPESHIFT	(_IOC_NRSHIFT+_IOC_NRBITS)
#define _IOC_SIZESHIFT	(_IOC_TYPESHIFT+_IOC_TYPEBITS)
#define _IOC_DIRSHIFT	(_IOC_SIZESHIFT+_IOC_SIZEBITS)

/*
 * Direction bits _IOC_NONE could be 0, but OSF/1 gives it a bit.
 * And this turns out useful to catch old ioctl numbers in header
 * files for us.
 */
#define _IOC_NONE	1U
#define _IOC_READ	2U
#define _IOC_WRITE	4U

#define _IOC(dir,type,nr,size) \
	(((dir)  << _IOC_DIRSHIFT) | \
	 ((type) << _IOC_TYPESHIFT) | \
	 ((nr)   << _IOC_NRSHIFT) | \
	 ((size) << _IOC_SIZESHIFT))

/* used to create numbers */
#define _IO(type,nr)		_IOC(_IOC_NONE,(type),(nr),0)
#define _IOR(type,nr,size)	_IOC(_IOC_READ,(type),(nr),sizeof(size))
#define _IOW(type,nr,size)	_IOC(_IOC_WRITE,(type),(nr),sizeof(size))
#define _IOWR(type,nr,size)	_IOC(_IOC_READ|_IOC_WRITE,(type),(nr),sizeof(size))

/* used to decode them.. */
#define _IOC_DIR(nr)		(((nr) >> _IOC_DIRSHIFT) & _IOC_DIRMASK)
#define _IOC_TYPE(nr)		(((nr) >> _IOC_TYPESHIFT) & _IOC_TYPEMASK)
#define _IOC_NR(nr)		(((nr) >> _IOC_NRSHIFT) & _IOC_NRMASK)
#define _IOC_SIZE(nr)		(((nr) >> _IOC_SIZESHIFT) & _IOC_SIZEMASK)

/* various drivers, such as the pcmcia stuff, need these... */
#define IOC_IN		(_IOC_WRITE << _IOC_DIRSHIFT)
#define IOC_OUT		(_IOC_READ << _IOC_DIRSHIFT)
#define IOC_INOUT	((_IOC_WRITE|_IOC_READ) << _IOC_DIRSHIFT)
#define IOCSIZE_MASK	(_IOC_SIZEMASK << _IOC_SIZESHIFT)
#define IOCSIZE_SHIFT	(_IOC_SIZESHIFT)

#endif