/****************************************************************************** * * Name: hwtimer.c - ACPI Power Management Timer Interface * $Revision: 4 $ * *****************************************************************************/ /****************************************************************************** * * 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 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; } /* 32-bit Timer */ else { DeltaTicks = (0xFFFFFFFF - StartTicks) + EndTicks; } } /* * 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 = */ /* 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); }