- 根目录:
- include
- linux
- mmtimer.h
/*
* Intel Multimedia Timer device interface
*
* This file is subject to the terms and conditions of the GNU General Public
* License. See the file "COPYING" in the main directory of this archive
* for more details.
*
* Copyright (c) 2001-2004 Silicon Graphics, Inc. All rights reserved.
*
* This file should define an interface compatible with the IA-PC Multimedia
* Timers Draft Specification (rev. 0.97) from Intel. Note that some
* hardware may not be able to safely export its registers to userspace,
* so the ioctl interface should support all necessary functionality.
*
* 11/01/01 - jbarnes - initial revision
* 9/10/04 - Christoph Lameter - remove interrupt support
* 9/17/04 - jbarnes - remove test program, move some #defines to the driver
*/
#ifndef _LINUX_MMTIMER_H
#define _LINUX_MMTIMER_H
/*
* Breakdown of the ioctl's available. An 'optional' next to the command
* indicates that supporting this command is optional, while 'required'
* commands must be implemented if conformance is desired.
*
* MMTIMER_GETOFFSET - optional
* Should return the offset (relative to the start of the page where the
* registers are mapped) for the counter in question.
*
* MMTIMER_GETRES - required
* The resolution of the clock in femto (10^-15) seconds
*
* MMTIMER_GETFREQ - required
* Frequency of the clock in Hz
*
* MMTIMER_GETBITS - required
* Number of bits in the clock's counter
*
* MMTIMER_MMAPAVAIL - required
* Returns nonzero if the registers can be mmap'd into userspace, 0 otherwise
*
* MMTIMER_GETCOUNTER - required
* Gets the current value in the counter
*/
#define MMTIMER_IOCTL_BASE 'm'
#define MMTIMER_GETOFFSET _IO(MMTIMER_IOCTL_BASE, 0)
#define MMTIMER_GETRES _IOR(MMTIMER_IOCTL_BASE, 1, unsigned long)
#define MMTIMER_GETFREQ _IOR(MMTIMER_IOCTL_BASE, 2, unsigned long)
#define MMTIMER_GETBITS _IO(MMTIMER_IOCTL_BASE, 4)
#define MMTIMER_MMAPAVAIL _IO(MMTIMER_IOCTL_BASE, 6)
#define MMTIMER_GETCOUNTER _IOR(MMTIMER_IOCTL_BASE, 9, unsigned long)
#endif /* _LINUX_MMTIMER_H */