LXR linux/include/uapi/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 */
  57