freebsd-skq/sys/contrib/dev/acpica/hwtimer.c

308 lines
12 KiB
C

/******************************************************************************
*
* Name: hwtimer.c - ACPI Power Management Timer Interface
* $Revision: 5 $
*
*****************************************************************************/
/******************************************************************************
*
* 1. Copyright Notice
*
* Some or all of this work - Copyright (c) 1999, 2000, 2001, Intel Corp.
* All rights reserved.
*
* 2. License
*
* 2.1. This is your license from Intel Corp. under its intellectual property
* rights. You may have additional license terms from the party that provided
* you this software, covering your right to use that party's intellectual
* property rights.
*
* 2.2. Intel grants, free of charge, to any person ("Licensee") obtaining a
* copy of the source code appearing in this file ("Covered Code") an
* irrevocable, perpetual, worldwide license under Intel's copyrights in the
* base code distributed originally by Intel ("Original Intel Code") to copy,
* make derivatives, distribute, use and display any portion of the Covered
* Code in any form, with the right to sublicense such rights; and
*
* 2.3. Intel grants Licensee a non-exclusive and non-transferable patent
* license (with the right to sublicense), under only those claims of Intel
* patents that are infringed by the Original Intel Code, to make, use, sell,
* offer to sell, and import the Covered Code and derivative works thereof
* solely to the minimum extent necessary to exercise the above copyright
* license, and in no event shall the patent license extend to any additions
* to or modifications of the Original Intel Code. No other license or right
* is granted directly or by implication, estoppel or otherwise;
*
* The above copyright and patent license is granted only if the following
* conditions are met:
*
* 3. Conditions
*
* 3.1. Redistribution of Source with Rights to Further Distribute Source.
* Redistribution of source code of any substantial portion of the Covered
* Code or modification with rights to further distribute source must include
* the above Copyright Notice, the above License, this list of Conditions,
* and the following Disclaimer and Export Compliance provision. In addition,
* Licensee must cause all Covered Code to which Licensee contributes to
* contain a file documenting the changes Licensee made to create that Covered
* Code and the date of any change. Licensee must include in that file the
* documentation of any changes made by any predecessor Licensee. Licensee
* must include a prominent statement that the modification is derived,
* directly or indirectly, from Original Intel Code.
*
* 3.2. Redistribution of Source with no Rights to Further Distribute Source.
* Redistribution of source code of any substantial portion of the Covered
* Code or modification without rights to further distribute source must
* include the following Disclaimer and Export Compliance provision in the
* documentation and/or other materials provided with distribution. In
* addition, Licensee may not authorize further sublicense of source of any
* portion of the Covered Code, and must include terms to the effect that the
* license from Licensee to its licensee is limited to the intellectual
* property embodied in the software Licensee provides to its licensee, and
* not to intellectual property embodied in modifications its licensee may
* make.
*
* 3.3. Redistribution of Executable. Redistribution in executable form of any
* substantial portion of the Covered Code or modification must reproduce the
* above Copyright Notice, and the following Disclaimer and Export Compliance
* provision in the documentation and/or other materials provided with the
* distribution.
*
* 3.4. Intel retains all right, title, and interest in and to the Original
* Intel Code.
*
* 3.5. Neither the name Intel nor any other trademark owned or controlled by
* Intel shall be used in advertising or otherwise to promote the sale, use or
* other dealings in products derived from or relating to the Covered Code
* without prior written authorization from Intel.
*
* 4. Disclaimer and Export Compliance
*
* 4.1. INTEL MAKES NO WARRANTY OF ANY KIND REGARDING ANY SOFTWARE PROVIDED
* HERE. ANY SOFTWARE ORIGINATING FROM INTEL OR DERIVED FROM INTEL SOFTWARE
* IS PROVIDED "AS IS," AND INTEL WILL NOT PROVIDE ANY SUPPORT, ASSISTANCE,
* INSTALLATION, TRAINING OR OTHER SERVICES. INTEL WILL NOT PROVIDE ANY
* UPDATES, ENHANCEMENTS OR EXTENSIONS. INTEL SPECIFICALLY DISCLAIMS ANY
* IMPLIED WARRANTIES OF MERCHANTABILITY, NONINFRINGEMENT AND FITNESS FOR A
* PARTICULAR PURPOSE.
*
* 4.2. IN NO EVENT SHALL INTEL HAVE ANY LIABILITY TO LICENSEE, ITS LICENSEES
* OR ANY OTHER THIRD PARTY, FOR ANY LOST PROFITS, LOST DATA, LOSS OF USE OR
* COSTS OF PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES, OR FOR ANY INDIRECT,
* SPECIAL OR CONSEQUENTIAL DAMAGES ARISING OUT OF THIS AGREEMENT, UNDER ANY
* CAUSE OF ACTION OR THEORY OF LIABILITY, AND IRRESPECTIVE OF WHETHER INTEL
* HAS ADVANCE NOTICE OF THE POSSIBILITY OF SUCH DAMAGES. THESE LIMITATIONS
* SHALL APPLY NOTWITHSTANDING THE FAILURE OF THE ESSENTIAL PURPOSE OF ANY
* LIMITED REMEDY.
*
* 4.3. Licensee shall not export, either directly or indirectly, any of this
* software or system incorporating such software without first obtaining any
* required license or other approval from the U. S. Department of Commerce or
* any other agency or department of the United States Government. In the
* event Licensee exports any such software from the United States or
* re-exports any such software from a foreign destination, Licensee shall
* ensure that the distribution and export/re-export of the software is in
* compliance with all laws, regulations, orders, or other restrictions of the
* U.S. Export Administration Regulations. Licensee agrees that neither it nor
* any of its subsidiaries will export/re-export any technical data, process,
* software, or service, directly or indirectly, to any country for which the
* United States government or any agency thereof requires an export license,
* other governmental approval, or letter of assurance, without first obtaining
* such license, approval or letter.
*
*****************************************************************************/
#include "acpi.h"
#include "achware.h"
#define _COMPONENT HARDWARE
MODULE_NAME ("hwtimer")
/******************************************************************************
*
* FUNCTION: AcpiGetTimerResolution
*
* PARAMETERS: none
*
* RETURN: Number of bits of resolution in the PM Timer (24 or 32).
*
* DESCRIPTION: Obtains resolution of the ACPI PM Timer.
*
******************************************************************************/
ACPI_STATUS
AcpiGetTimerResolution (
UINT32 *Resolution)
{
FUNCTION_TRACE ("AcpiGetTimerResolution");
if (!Resolution)
{
return_ACPI_STATUS (AE_BAD_PARAMETER);
}
if (0 == AcpiGbl_FADT->TmrValExt)
{
*Resolution = 24;
}
else
{
*Resolution = 32;
}
return_ACPI_STATUS (AE_OK);
}
/******************************************************************************
*
* FUNCTION: AcpiGetTimer
*
* PARAMETERS: none
*
* RETURN: Current value of the ACPI PM Timer (in ticks).
*
* DESCRIPTION: Obtains current value of ACPI PM Timer.
*
******************************************************************************/
ACPI_STATUS
AcpiGetTimer (
UINT32 *Ticks)
{
FUNCTION_TRACE ("AcpiGetTimer");
if (!Ticks)
{
return_ACPI_STATUS (AE_BAD_PARAMETER);
}
*Ticks = AcpiOsIn32 ((ACPI_IO_ADDRESS) ACPI_GET_ADDRESS (AcpiGbl_FADT->XPmTmrBlk.Address));
return_ACPI_STATUS (AE_OK);
}
/******************************************************************************
*
* FUNCTION: AcpiGetTimerDuration
*
* PARAMETERS: StartTicks
* EndTicks
* TimeElapsed
*
* RETURN: TimeElapsed
*
* DESCRIPTION: Computes the time elapsed (in microseconds) between two
* PM Timer time stamps, taking into account the possibility of
* rollovers, the timer resolution, and timer frequency.
*
* The PM Timer's clock ticks at roughly 3.6 times per
* _microsecond_, and its clock continues through Cx state
* transitions (unlike many CPU timestamp counters) -- making it
* a versatile and accurate timer.
*
* Note that this function accomodates only a single timer
* rollover. Thus for 24-bit timers, this function should only
* be used for calculating durations less than ~4.6 seconds
* (~20 hours for 32-bit timers).
*
******************************************************************************/
ACPI_STATUS
AcpiGetTimerDuration (
UINT32 StartTicks,
UINT32 EndTicks,
UINT32 *TimeElapsed)
{
UINT32 DeltaTicks = 0;
UINT32 Seconds = 0;
UINT32 Milliseconds = 0;
UINT32 Microseconds = 0;
UINT32 Remainder = 0;
FUNCTION_TRACE ("AcpiGetTimerDuration");
if (!TimeElapsed)
{
return_ACPI_STATUS (AE_BAD_PARAMETER);
}
/*
* Compute Tick Delta:
* -------------------
* Handle (max one) timer rollovers on 24- versus 32-bit timers.
*/
if (StartTicks < EndTicks)
{
DeltaTicks = EndTicks - StartTicks;
}
else if (StartTicks > EndTicks)
{
/* 24-bit Timer */
if (0 == AcpiGbl_FADT->TmrValExt)
{
DeltaTicks = (((0x00FFFFFF - StartTicks) + EndTicks) & 0x00FFFFFF);
}
/* 32-bit Timer */
else
{
DeltaTicks = (0xFFFFFFFF - StartTicks) + EndTicks;
}
}
else
{
*TimeElapsed = 0;
return_ACPI_STATUS (AE_OK);
}
/*
* Compute Duration:
* -----------------
* Since certain compilers (gcc/Linux, argh!) don't support 64-bit
* divides in kernel-space we have to do some trickery to preserve
* accuracy while using 32-bit math.
*
* TODO: Change to use 64-bit math when supported.
*
* The process is as follows:
* 1. Compute the number of seconds by dividing Delta Ticks by
* the timer frequency.
* 2. Compute the number of milliseconds in the remainder from step #1
* by multiplying by 1000 and then dividing by the timer frequency.
* 3. Compute the number of microseconds in the remainder from step #2
* by multiplying by 1000 and then dividing by the timer frequency.
* 4. Add the results from steps 1, 2, and 3 to get the total duration.
*
* Example: The time elapsed for DeltaTicks = 0xFFFFFFFF should be
* 1199864031 microseconds. This is computed as follows:
* Step #1: Seconds = 1199; Remainder = 3092840
* Step #2: Milliseconds = 864; Remainder = 113120
* Step #3: Microseconds = 31; Remainder = <don't care!>
*/
/* Step #1 */
Seconds = DeltaTicks / PM_TIMER_FREQUENCY;
Remainder = DeltaTicks % PM_TIMER_FREQUENCY;
/* Step #2 */
Milliseconds = (Remainder * 1000) / PM_TIMER_FREQUENCY;
Remainder = (Remainder * 1000) % PM_TIMER_FREQUENCY;
/* Step #3 */
Microseconds = (Remainder * 1000) / PM_TIMER_FREQUENCY;
/* Step #4 */
*TimeElapsed = Seconds * 1000000;
*TimeElapsed += Milliseconds * 1000;
*TimeElapsed += Microseconds;
return_ACPI_STATUS (AE_OK);
}