include/linux/mmtimer.h

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