include/uapi/linux/mmtimer.h

   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 */