hwtimer.c revision 306536
1251875Speter/****************************************************************************** 2251875Speter * 3251875Speter * Name: hwtimer.c - ACPI Power Management Timer Interface 4251875Speter * 5251875Speter *****************************************************************************/ 6251875Speter 7251875Speter/* 8251875Speter * Copyright (C) 2000 - 2016, Intel Corp. 9251875Speter * All rights reserved. 10251875Speter * 11251875Speter * Redistribution and use in source and binary forms, with or without 12251875Speter * modification, are permitted provided that the following conditions 13251875Speter * are met: 14251875Speter * 1. Redistributions of source code must retain the above copyright 15251875Speter * notice, this list of conditions, and the following disclaimer, 16251875Speter * without modification. 17251875Speter * 2. Redistributions in binary form must reproduce at minimum a disclaimer 18251875Speter * substantially similar to the "NO WARRANTY" disclaimer below 19251875Speter * ("Disclaimer") and any redistribution must be conditioned upon 20251875Speter * including a substantially similar Disclaimer requirement for further 21251875Speter * binary redistribution. 22251875Speter * 3. Neither the names of the above-listed copyright holders nor the names 23251875Speter * of any contributors may be used to endorse or promote products derived 24251875Speter * from this software without specific prior written permission. 25251875Speter * 26251875Speter * Alternatively, this software may be distributed under the terms of the 27251875Speter * GNU General Public License ("GPL") version 2 as published by the Free 28251875Speter * Software Foundation. 29251875Speter * 30251875Speter * NO WARRANTY 31251875Speter * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS 32251875Speter * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT 33251875Speter * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTIBILITY AND FITNESS FOR 34251875Speter * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT 35251875Speter * HOLDERS OR CONTRIBUTORS BE LIABLE FOR SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 36251875Speter * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 37251875Speter * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 38251875Speter * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, 39251875Speter * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING 40251875Speter * IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE 41253734Speter * POSSIBILITY OF SUCH DAMAGES. 42253734Speter */ 43253734Speter 44253734Speter#define EXPORT_ACPI_INTERFACES 45251875Speter 46251875Speter#include <contrib/dev/acpica/include/acpi.h> 47251875Speter#include <contrib/dev/acpica/include/accommon.h> 48251875Speter 49251875Speter#define _COMPONENT ACPI_HARDWARE 50251875Speter ACPI_MODULE_NAME ("hwtimer") 51251875Speter 52251875Speter 53251875Speter#if (!ACPI_REDUCED_HARDWARE) /* Entire module */ 54251875Speter/****************************************************************************** 55251875Speter * 56251875Speter * FUNCTION: AcpiGetTimerResolution 57251875Speter * 58251875Speter * PARAMETERS: Resolution - Where the resolution is returned 59251875Speter * 60251875Speter * RETURN: Status and timer resolution 61251875Speter * 62251875Speter * DESCRIPTION: Obtains resolution of the ACPI PM Timer (24 or 32 bits). 63251875Speter * 64251875Speter ******************************************************************************/ 65251875Speter 66251875SpeterACPI_STATUS 67253734SpeterAcpiGetTimerResolution ( 68253734Speter UINT32 *Resolution) 69253734Speter{ 70253734Speter ACPI_FUNCTION_TRACE (AcpiGetTimerResolution); 71251875Speter 72251875Speter 73251875Speter if (!Resolution) 74251875Speter { 75251875Speter return_ACPI_STATUS (AE_BAD_PARAMETER); 76251875Speter } 77251875Speter 78251875Speter if ((AcpiGbl_FADT.Flags & ACPI_FADT_32BIT_TIMER) == 0) 79251875Speter { 80251875Speter *Resolution = 24; 81251875Speter } 82251875Speter else 83251875Speter { 84251875Speter *Resolution = 32; 85251875Speter } 86251875Speter 87251875Speter return_ACPI_STATUS (AE_OK); 88251875Speter} 89251875Speter 90251875SpeterACPI_EXPORT_SYMBOL (AcpiGetTimerResolution) 91253734Speter 92251875Speter 93251875Speter/****************************************************************************** 94251875Speter * 95251875Speter * FUNCTION: AcpiGetTimer 96251875Speter * 97251875Speter * PARAMETERS: Ticks - Where the timer value is returned 98251875Speter * 99251875Speter * RETURN: Status and current timer value (ticks) 100251875Speter * 101251875Speter * DESCRIPTION: Obtains current value of ACPI PM Timer (in ticks). 102251875Speter * 103251875Speter ******************************************************************************/ 104253734Speter 105253734SpeterACPI_STATUS 106251875SpeterAcpiGetTimer ( 107251875Speter UINT32 *Ticks) 108251875Speter{ 109251875Speter ACPI_STATUS Status; 110251875Speter 111251875Speter 112251875Speter ACPI_FUNCTION_TRACE (AcpiGetTimer); 113251875Speter 114251875Speter 115251875Speter if (!Ticks) 116251875Speter { 117253734Speter return_ACPI_STATUS (AE_BAD_PARAMETER); 118251875Speter } 119251875Speter 120251875Speter /* ACPI 5.0A: PM Timer is optional */ 121251875Speter 122253734Speter if (!AcpiGbl_FADT.XPmTimerBlock.Address) 123251875Speter { 124251875Speter return_ACPI_STATUS (AE_SUPPORT); 125251875Speter } 126251875Speter 127251875Speter Status = AcpiHwRead (Ticks, &AcpiGbl_FADT.XPmTimerBlock); 128251875Speter return_ACPI_STATUS (Status); 129251875Speter} 130251875Speter 131251875SpeterACPI_EXPORT_SYMBOL (AcpiGetTimer) 132251875Speter 133251875Speter 134251875Speter/****************************************************************************** 135251875Speter * 136251875Speter * FUNCTION: AcpiGetTimerDuration 137253734Speter * 138253734Speter * PARAMETERS: StartTicks - Starting timestamp 139251875Speter * EndTicks - End timestamp 140251875Speter * TimeElapsed - Where the elapsed time is returned 141251875Speter * 142251875Speter * RETURN: Status and TimeElapsed 143251875Speter * 144253734Speter * DESCRIPTION: Computes the time elapsed (in microseconds) between two 145253734Speter * PM Timer time stamps, taking into account the possibility of 146251875Speter * rollovers, the timer resolution, and timer frequency. 147251875Speter * 148251875Speter * The PM Timer's clock ticks at roughly 3.6 times per 149251875Speter * _microsecond_, and its clock continues through Cx state 150251875Speter * transitions (unlike many CPU timestamp counters) -- making it 151251875Speter * a versatile and accurate timer. 152251875Speter * 153251875Speter * Note that this function accommodates only a single timer 154251875Speter * rollover. Thus for 24-bit timers, this function should only 155251875Speter * be used for calculating durations less than ~4.6 seconds 156 * (~20 minutes for 32-bit timers) -- calculations below: 157 * 158 * 2**24 Ticks / 3,600,000 Ticks/Sec = 4.66 sec 159 * 2**32 Ticks / 3,600,000 Ticks/Sec = 1193 sec or 19.88 minutes 160 * 161 ******************************************************************************/ 162 163ACPI_STATUS 164AcpiGetTimerDuration ( 165 UINT32 StartTicks, 166 UINT32 EndTicks, 167 UINT32 *TimeElapsed) 168{ 169 ACPI_STATUS Status; 170 UINT32 DeltaTicks; 171 UINT64 Quotient; 172 173 174 ACPI_FUNCTION_TRACE (AcpiGetTimerDuration); 175 176 177 if (!TimeElapsed) 178 { 179 return_ACPI_STATUS (AE_BAD_PARAMETER); 180 } 181 182 /* ACPI 5.0A: PM Timer is optional */ 183 184 if (!AcpiGbl_FADT.XPmTimerBlock.Address) 185 { 186 return_ACPI_STATUS (AE_SUPPORT); 187 } 188 189 /* 190 * Compute Tick Delta: 191 * Handle (max one) timer rollovers on 24-bit versus 32-bit timers. 192 */ 193 if (StartTicks < EndTicks) 194 { 195 DeltaTicks = EndTicks - StartTicks; 196 } 197 else if (StartTicks > EndTicks) 198 { 199 if ((AcpiGbl_FADT.Flags & ACPI_FADT_32BIT_TIMER) == 0) 200 { 201 /* 24-bit Timer */ 202 203 DeltaTicks = (((0x00FFFFFF - StartTicks) + EndTicks) & 0x00FFFFFF); 204 } 205 else 206 { 207 /* 32-bit Timer */ 208 209 DeltaTicks = (0xFFFFFFFF - StartTicks) + EndTicks; 210 } 211 } 212 else /* StartTicks == EndTicks */ 213 { 214 *TimeElapsed = 0; 215 return_ACPI_STATUS (AE_OK); 216 } 217 218 /* 219 * Compute Duration (Requires a 64-bit multiply and divide): 220 * 221 * TimeElapsed (microseconds) = 222 * (DeltaTicks * ACPI_USEC_PER_SEC) / ACPI_PM_TIMER_FREQUENCY; 223 */ 224 Status = AcpiUtShortDivide (((UINT64) DeltaTicks) * ACPI_USEC_PER_SEC, 225 ACPI_PM_TIMER_FREQUENCY, &Quotient, NULL); 226 227 *TimeElapsed = (UINT32) Quotient; 228 return_ACPI_STATUS (Status); 229} 230 231ACPI_EXPORT_SYMBOL (AcpiGetTimerDuration) 232 233#endif /* !ACPI_REDUCED_HARDWARE */ 234