Home | History | Annotate | Download | only in linux
      1 /* SPDX-License-Identifier: GPL-2.0 WITH Linux-syscall-note */
      2 /*
      3  * Intel Multimedia Timer device interface
      4  *
      5  * This file is subject to the terms and conditions of the GNU General Public
      6  * License.  See the file "COPYING" in the main directory of this archive
      7  * for more details.
      8  *
      9  * Copyright (c) 2001-2004 Silicon Graphics, Inc.  All rights reserved.
     10  *
     11  * This file should define an interface compatible with the IA-PC Multimedia
     12  * Timers Draft Specification (rev. 0.97) from Intel.  Note that some
     13  * hardware may not be able to safely export its registers to userspace,
     14  * so the ioctl interface should support all necessary functionality.
     15  *
     16  * 11/01/01 - jbarnes - initial revision
     17  * 9/10/04 - Christoph Lameter - remove interrupt support
     18  * 9/17/04 - jbarnes - remove test program, move some #defines to the driver
     19  */
     20 
     21 #ifndef _LINUX_MMTIMER_H
     22 #define _LINUX_MMTIMER_H
     23 
     24 /*
     25  * Breakdown of the ioctl's available.  An 'optional' next to the command
     26  * indicates that supporting this command is optional, while 'required'
     27  * commands must be implemented if conformance is desired.
     28  *
     29  * MMTIMER_GETOFFSET - optional
     30  *   Should return the offset (relative to the start of the page where the
     31  *   registers are mapped) for the counter in question.
     32  *
     33  * MMTIMER_GETRES - required
     34  *   The resolution of the clock in femto (10^-15) seconds
     35  *
     36  * MMTIMER_GETFREQ - required
     37  *   Frequency of the clock in Hz
     38  *
     39  * MMTIMER_GETBITS - required
     40  *   Number of bits in the clock's counter
     41  *
     42  * MMTIMER_MMAPAVAIL - required
     43  *   Returns nonzero if the registers can be mmap'd into userspace, 0 otherwise
     44  *
     45  * MMTIMER_GETCOUNTER - required
     46  *   Gets the current value in the counter
     47  */
     48 #define MMTIMER_IOCTL_BASE 'm'
     49 
     50 #define MMTIMER_GETOFFSET _IO(MMTIMER_IOCTL_BASE, 0)
     51 #define MMTIMER_GETRES _IOR(MMTIMER_IOCTL_BASE, 1, unsigned long)
     52 #define MMTIMER_GETFREQ _IOR(MMTIMER_IOCTL_BASE, 2, unsigned long)
     53 #define MMTIMER_GETBITS _IO(MMTIMER_IOCTL_BASE, 4)
     54 #define MMTIMER_MMAPAVAIL _IO(MMTIMER_IOCTL_BASE, 6)
     55 #define MMTIMER_GETCOUNTER _IOR(MMTIMER_IOCTL_BASE, 9, unsigned long)
     56 
     57 #endif /* _LINUX_MMTIMER_H */
     58