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       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 */