hwtimer.c revision 78986
171867Smsmith 271867Smsmith/****************************************************************************** 371867Smsmith * 471867Smsmith * Name: hwtimer.c - ACPI Power Management Timer Interface 578986Smsmith * $Revision: 10 $ 671867Smsmith * 771867Smsmith *****************************************************************************/ 871867Smsmith 971867Smsmith/****************************************************************************** 1071867Smsmith * 1171867Smsmith * 1. Copyright Notice 1271867Smsmith * 1371867Smsmith * Some or all of this work - Copyright (c) 1999, 2000, 2001, Intel Corp. 1471867Smsmith * All rights reserved. 1571867Smsmith * 1671867Smsmith * 2. License 1771867Smsmith * 1871867Smsmith * 2.1. This is your license from Intel Corp. under its intellectual property 1971867Smsmith * rights. You may have additional license terms from the party that provided 2071867Smsmith * you this software, covering your right to use that party's intellectual 2171867Smsmith * property rights. 2271867Smsmith * 2371867Smsmith * 2.2. Intel grants, free of charge, to any person ("Licensee") obtaining a 2471867Smsmith * copy of the source code appearing in this file ("Covered Code") an 2571867Smsmith * irrevocable, perpetual, worldwide license under Intel's copyrights in the 2671867Smsmith * base code distributed originally by Intel ("Original Intel Code") to copy, 2771867Smsmith * make derivatives, distribute, use and display any portion of the Covered 2871867Smsmith * Code in any form, with the right to sublicense such rights; and 2971867Smsmith * 3071867Smsmith * 2.3. Intel grants Licensee a non-exclusive and non-transferable patent 3171867Smsmith * license (with the right to sublicense), under only those claims of Intel 3271867Smsmith * patents that are infringed by the Original Intel Code, to make, use, sell, 3371867Smsmith * offer to sell, and import the Covered Code and derivative works thereof 3471867Smsmith * solely to the minimum extent necessary to exercise the above copyright 3571867Smsmith * license, and in no event shall the patent license extend to any additions 3671867Smsmith * to or modifications of the Original Intel Code. No other license or right 3771867Smsmith * is granted directly or by implication, estoppel or otherwise; 3871867Smsmith * 3971867Smsmith * The above copyright and patent license is granted only if the following 4071867Smsmith * conditions are met: 4171867Smsmith * 4271867Smsmith * 3. Conditions 4371867Smsmith * 4471867Smsmith * 3.1. Redistribution of Source with Rights to Further Distribute Source. 4571867Smsmith * Redistribution of source code of any substantial portion of the Covered 4671867Smsmith * Code or modification with rights to further distribute source must include 4771867Smsmith * the above Copyright Notice, the above License, this list of Conditions, 4871867Smsmith * and the following Disclaimer and Export Compliance provision. In addition, 4971867Smsmith * Licensee must cause all Covered Code to which Licensee contributes to 5071867Smsmith * contain a file documenting the changes Licensee made to create that Covered 5171867Smsmith * Code and the date of any change. Licensee must include in that file the 5271867Smsmith * documentation of any changes made by any predecessor Licensee. Licensee 5371867Smsmith * must include a prominent statement that the modification is derived, 5471867Smsmith * directly or indirectly, from Original Intel Code. 5571867Smsmith * 5671867Smsmith * 3.2. Redistribution of Source with no Rights to Further Distribute Source. 5771867Smsmith * Redistribution of source code of any substantial portion of the Covered 5871867Smsmith * Code or modification without rights to further distribute source must 5971867Smsmith * include the following Disclaimer and Export Compliance provision in the 6071867Smsmith * documentation and/or other materials provided with distribution. In 6171867Smsmith * addition, Licensee may not authorize further sublicense of source of any 6271867Smsmith * portion of the Covered Code, and must include terms to the effect that the 6371867Smsmith * license from Licensee to its licensee is limited to the intellectual 6471867Smsmith * property embodied in the software Licensee provides to its licensee, and 6571867Smsmith * not to intellectual property embodied in modifications its licensee may 6671867Smsmith * make. 6771867Smsmith * 6871867Smsmith * 3.3. Redistribution of Executable. Redistribution in executable form of any 6971867Smsmith * substantial portion of the Covered Code or modification must reproduce the 7071867Smsmith * above Copyright Notice, and the following Disclaimer and Export Compliance 7171867Smsmith * provision in the documentation and/or other materials provided with the 7271867Smsmith * distribution. 7371867Smsmith * 7471867Smsmith * 3.4. Intel retains all right, title, and interest in and to the Original 7571867Smsmith * Intel Code. 7671867Smsmith * 7771867Smsmith * 3.5. Neither the name Intel nor any other trademark owned or controlled by 7871867Smsmith * Intel shall be used in advertising or otherwise to promote the sale, use or 7971867Smsmith * other dealings in products derived from or relating to the Covered Code 8071867Smsmith * without prior written authorization from Intel. 8171867Smsmith * 8271867Smsmith * 4. Disclaimer and Export Compliance 8371867Smsmith * 8471867Smsmith * 4.1. INTEL MAKES NO WARRANTY OF ANY KIND REGARDING ANY SOFTWARE PROVIDED 8571867Smsmith * HERE. ANY SOFTWARE ORIGINATING FROM INTEL OR DERIVED FROM INTEL SOFTWARE 8671867Smsmith * IS PROVIDED "AS IS," AND INTEL WILL NOT PROVIDE ANY SUPPORT, ASSISTANCE, 8771867Smsmith * INSTALLATION, TRAINING OR OTHER SERVICES. INTEL WILL NOT PROVIDE ANY 8871867Smsmith * UPDATES, ENHANCEMENTS OR EXTENSIONS. INTEL SPECIFICALLY DISCLAIMS ANY 8971867Smsmith * IMPLIED WARRANTIES OF MERCHANTABILITY, NONINFRINGEMENT AND FITNESS FOR A 9071867Smsmith * PARTICULAR PURPOSE. 9171867Smsmith * 9271867Smsmith * 4.2. IN NO EVENT SHALL INTEL HAVE ANY LIABILITY TO LICENSEE, ITS LICENSEES 9371867Smsmith * OR ANY OTHER THIRD PARTY, FOR ANY LOST PROFITS, LOST DATA, LOSS OF USE OR 9471867Smsmith * COSTS OF PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES, OR FOR ANY INDIRECT, 9571867Smsmith * SPECIAL OR CONSEQUENTIAL DAMAGES ARISING OUT OF THIS AGREEMENT, UNDER ANY 9671867Smsmith * CAUSE OF ACTION OR THEORY OF LIABILITY, AND IRRESPECTIVE OF WHETHER INTEL 9771867Smsmith * HAS ADVANCE NOTICE OF THE POSSIBILITY OF SUCH DAMAGES. THESE LIMITATIONS 9871867Smsmith * SHALL APPLY NOTWITHSTANDING THE FAILURE OF THE ESSENTIAL PURPOSE OF ANY 9971867Smsmith * LIMITED REMEDY. 10071867Smsmith * 10171867Smsmith * 4.3. Licensee shall not export, either directly or indirectly, any of this 10271867Smsmith * software or system incorporating such software without first obtaining any 10371867Smsmith * required license or other approval from the U. S. Department of Commerce or 10471867Smsmith * any other agency or department of the United States Government. In the 10571867Smsmith * event Licensee exports any such software from the United States or 10671867Smsmith * re-exports any such software from a foreign destination, Licensee shall 10771867Smsmith * ensure that the distribution and export/re-export of the software is in 10871867Smsmith * compliance with all laws, regulations, orders, or other restrictions of the 10971867Smsmith * U.S. Export Administration Regulations. Licensee agrees that neither it nor 11071867Smsmith * any of its subsidiaries will export/re-export any technical data, process, 11171867Smsmith * software, or service, directly or indirectly, to any country for which the 11271867Smsmith * United States government or any agency thereof requires an export license, 11371867Smsmith * other governmental approval, or letter of assurance, without first obtaining 11471867Smsmith * such license, approval or letter. 11571867Smsmith * 11671867Smsmith *****************************************************************************/ 11771867Smsmith 11871867Smsmith#include "acpi.h" 11971867Smsmith#include "achware.h" 12071867Smsmith 12177424Smsmith#define _COMPONENT ACPI_HARDWARE 12271867Smsmith MODULE_NAME ("hwtimer") 12371867Smsmith 12471867Smsmith 12571867Smsmith/****************************************************************************** 12671867Smsmith * 12771867Smsmith * FUNCTION: AcpiGetTimerResolution 12871867Smsmith * 12971867Smsmith * PARAMETERS: none 13071867Smsmith * 13171867Smsmith * RETURN: Number of bits of resolution in the PM Timer (24 or 32). 13271867Smsmith * 13371867Smsmith * DESCRIPTION: Obtains resolution of the ACPI PM Timer. 13471867Smsmith * 13571867Smsmith ******************************************************************************/ 13671867Smsmith 13771867SmsmithACPI_STATUS 13871867SmsmithAcpiGetTimerResolution ( 13971867Smsmith UINT32 *Resolution) 14071867Smsmith{ 14178986Smsmith ACPI_STATUS Status; 14277424Smsmith 14378986Smsmith 14471867Smsmith FUNCTION_TRACE ("AcpiGetTimerResolution"); 14571867Smsmith 14677424Smsmith 14777424Smsmith /* Ensure that ACPI has been initialized */ 14877424Smsmith 14977424Smsmith ACPI_IS_INITIALIZATION_COMPLETE (Status); 15077424Smsmith if (ACPI_FAILURE (Status)) 15177424Smsmith { 15277424Smsmith return_ACPI_STATUS (Status); 15377424Smsmith } 15477424Smsmith 15571867Smsmith if (!Resolution) 15671867Smsmith { 15771867Smsmith return_ACPI_STATUS (AE_BAD_PARAMETER); 15871867Smsmith } 15971867Smsmith 16071867Smsmith if (0 == AcpiGbl_FADT->TmrValExt) 16171867Smsmith { 16271867Smsmith *Resolution = 24; 16371867Smsmith } 16471867Smsmith else 16571867Smsmith { 16671867Smsmith *Resolution = 32; 16771867Smsmith } 16871867Smsmith 16971867Smsmith return_ACPI_STATUS (AE_OK); 17071867Smsmith} 17171867Smsmith 17271867Smsmith 17371867Smsmith/****************************************************************************** 17471867Smsmith * 17571867Smsmith * FUNCTION: AcpiGetTimer 17671867Smsmith * 17771867Smsmith * PARAMETERS: none 17871867Smsmith * 17971867Smsmith * RETURN: Current value of the ACPI PM Timer (in ticks). 18071867Smsmith * 18171867Smsmith * DESCRIPTION: Obtains current value of ACPI PM Timer. 18271867Smsmith * 18371867Smsmith ******************************************************************************/ 18471867Smsmith 18571867SmsmithACPI_STATUS 18671867SmsmithAcpiGetTimer ( 18771867Smsmith UINT32 *Ticks) 18871867Smsmith{ 18978986Smsmith ACPI_STATUS Status; 19077424Smsmith 19178986Smsmith 19271867Smsmith FUNCTION_TRACE ("AcpiGetTimer"); 19371867Smsmith 19477424Smsmith 19577424Smsmith /* Ensure that ACPI has been initialized */ 19677424Smsmith 19777424Smsmith ACPI_IS_INITIALIZATION_COMPLETE (Status); 19877424Smsmith if (ACPI_FAILURE (Status)) 19977424Smsmith { 20077424Smsmith return_ACPI_STATUS (Status); 20177424Smsmith } 20277424Smsmith 20371867Smsmith if (!Ticks) 20471867Smsmith { 20571867Smsmith return_ACPI_STATUS (AE_BAD_PARAMETER); 20671867Smsmith } 20771867Smsmith 20871867Smsmith *Ticks = AcpiOsIn32 ((ACPI_IO_ADDRESS) ACPI_GET_ADDRESS (AcpiGbl_FADT->XPmTmrBlk.Address)); 20971867Smsmith 21071867Smsmith return_ACPI_STATUS (AE_OK); 21171867Smsmith} 21271867Smsmith 21371867Smsmith 21471867Smsmith/****************************************************************************** 21571867Smsmith * 21671867Smsmith * FUNCTION: AcpiGetTimerDuration 21771867Smsmith * 21871867Smsmith * PARAMETERS: StartTicks 21971867Smsmith * EndTicks 22071867Smsmith * TimeElapsed 22171867Smsmith * 22277424Smsmith * RETURN: TimeElapsed 22371867Smsmith * 22471867Smsmith * DESCRIPTION: Computes the time elapsed (in microseconds) between two 22571867Smsmith * PM Timer time stamps, taking into account the possibility of 22677424Smsmith * rollovers, the timer resolution, and timer frequency. 22777424Smsmith * 22877424Smsmith * The PM Timer's clock ticks at roughly 3.6 times per 22971867Smsmith * _microsecond_, and its clock continues through Cx state 23071867Smsmith * transitions (unlike many CPU timestamp counters) -- making it 23171867Smsmith * a versatile and accurate timer. 23271867Smsmith * 23377424Smsmith * Note that this function accomodates only a single timer 23471867Smsmith * rollover. Thus for 24-bit timers, this function should only 23577424Smsmith * be used for calculating durations less than ~4.6 seconds 23671867Smsmith * (~20 hours for 32-bit timers). 23771867Smsmith * 23871867Smsmith ******************************************************************************/ 23971867Smsmith 24071867SmsmithACPI_STATUS 24171867SmsmithAcpiGetTimerDuration ( 24271867Smsmith UINT32 StartTicks, 24371867Smsmith UINT32 EndTicks, 24471867Smsmith UINT32 *TimeElapsed) 24571867Smsmith{ 24671867Smsmith UINT32 DeltaTicks = 0; 24771867Smsmith UINT32 Seconds = 0; 24871867Smsmith UINT32 Milliseconds = 0; 24971867Smsmith UINT32 Microseconds = 0; 25071867Smsmith UINT32 Remainder = 0; 25171867Smsmith 25278986Smsmith 25371867Smsmith FUNCTION_TRACE ("AcpiGetTimerDuration"); 25471867Smsmith 25577424Smsmith if (!TimeElapsed) 25671867Smsmith { 25771867Smsmith return_ACPI_STATUS (AE_BAD_PARAMETER); 25871867Smsmith } 25971867Smsmith 26077424Smsmith /* 26171867Smsmith * Compute Tick Delta: 26271867Smsmith * ------------------- 26373561Smsmith * Handle (max one) timer rollovers on 24- versus 32-bit timers. 26471867Smsmith */ 26571867Smsmith if (StartTicks < EndTicks) 26671867Smsmith { 26771867Smsmith DeltaTicks = EndTicks - StartTicks; 26871867Smsmith } 26977424Smsmith else if (StartTicks > EndTicks) 27071867Smsmith { 27171867Smsmith /* 24-bit Timer */ 27271867Smsmith if (0 == AcpiGbl_FADT->TmrValExt) 27371867Smsmith { 27473561Smsmith DeltaTicks = (((0x00FFFFFF - StartTicks) + EndTicks) & 0x00FFFFFF); 27571867Smsmith } 27671867Smsmith /* 32-bit Timer */ 27777424Smsmith else 27871867Smsmith { 27971867Smsmith DeltaTicks = (0xFFFFFFFF - StartTicks) + EndTicks; 28071867Smsmith } 28171867Smsmith } 28273561Smsmith else 28373561Smsmith { 28473561Smsmith *TimeElapsed = 0; 28573561Smsmith return_ACPI_STATUS (AE_OK); 28673561Smsmith } 28771867Smsmith 28877424Smsmith /* 28971867Smsmith * Compute Duration: 29071867Smsmith * ----------------- 29177424Smsmith * Since certain compilers (gcc/Linux, argh!) don't support 64-bit 29277424Smsmith * divides in kernel-space we have to do some trickery to preserve 29371867Smsmith * accuracy while using 32-bit math. 29471867Smsmith * 29577424Smsmith * TBD: Change to use 64-bit math when supported. 29677424Smsmith * 29771867Smsmith * The process is as follows: 29877424Smsmith * 1. Compute the number of seconds by dividing Delta Ticks by 29971867Smsmith * the timer frequency. 30071867Smsmith * 2. Compute the number of milliseconds in the remainder from step #1 30171867Smsmith * by multiplying by 1000 and then dividing by the timer frequency. 30271867Smsmith * 3. Compute the number of microseconds in the remainder from step #2 30371867Smsmith * by multiplying by 1000 and then dividing by the timer frequency. 30471867Smsmith * 4. Add the results from steps 1, 2, and 3 to get the total duration. 30571867Smsmith * 30677424Smsmith * Example: The time elapsed for DeltaTicks = 0xFFFFFFFF should be 30771867Smsmith * 1199864031 microseconds. This is computed as follows: 30871867Smsmith * Step #1: Seconds = 1199; Remainder = 3092840 30971867Smsmith * Step #2: Milliseconds = 864; Remainder = 113120 31071867Smsmith * Step #3: Microseconds = 31; Remainder = <don't care!> 31171867Smsmith */ 31271867Smsmith 31371867Smsmith /* Step #1 */ 31471867Smsmith Seconds = DeltaTicks / PM_TIMER_FREQUENCY; 31571867Smsmith Remainder = DeltaTicks % PM_TIMER_FREQUENCY; 31671867Smsmith 31771867Smsmith /* Step #2 */ 31871867Smsmith Milliseconds = (Remainder * 1000) / PM_TIMER_FREQUENCY; 31971867Smsmith Remainder = (Remainder * 1000) % PM_TIMER_FREQUENCY; 32071867Smsmith 32171867Smsmith /* Step #3 */ 32271867Smsmith Microseconds = (Remainder * 1000) / PM_TIMER_FREQUENCY; 32371867Smsmith 32471867Smsmith /* Step #4 */ 32571867Smsmith *TimeElapsed = Seconds * 1000000; 32671867Smsmith *TimeElapsed += Milliseconds * 1000; 32771867Smsmith *TimeElapsed += Microseconds; 32871867Smsmith 32971867Smsmith return_ACPI_STATUS (AE_OK); 33071867Smsmith} 33171867Smsmith 33271867Smsmith 333