| /****************************************************************************** |
| * |
| * Name: hwtimer.c - ACPI Power Management Timer Interface |
| * |
| *****************************************************************************/ |
| |
| /* |
| * Copyright (C) 2000 - 2016, Intel Corp. |
| * All rights reserved. |
| * |
| * Redistribution and use in source and binary forms, with or without |
| * modification, are permitted provided that the following conditions |
| * are met: |
| * 1. Redistributions of source code must retain the above copyright |
| * notice, this list of conditions, and the following disclaimer, |
| * without modification. |
| * 2. Redistributions in binary form must reproduce at minimum a disclaimer |
| * substantially similar to the "NO WARRANTY" disclaimer below |
| * ("Disclaimer") and any redistribution must be conditioned upon |
| * including a substantially similar Disclaimer requirement for further |
| * binary redistribution. |
| * 3. Neither the names of the above-listed copyright holders nor the names |
| * of any contributors may be used to endorse or promote products derived |
| * from this software without specific prior written permission. |
| * |
| * Alternatively, this software may be distributed under the terms of the |
| * GNU General Public License ("GPL") version 2 as published by the Free |
| * Software Foundation. |
| * |
| * NO WARRANTY |
| * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS |
| * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT |
| * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTIBILITY AND FITNESS FOR |
| * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT |
| * HOLDERS OR CONTRIBUTORS BE LIABLE FOR SPECIAL, EXEMPLARY, OR CONSEQUENTIAL |
| * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS |
| * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) |
| * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, |
| * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING |
| * IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE |
| * POSSIBILITY OF SUCH DAMAGES. |
| */ |
| |
| #define EXPORT_ACPI_INTERFACES |
| |
| #include "acpi.h" |
| #include "accommon.h" |
| |
| #define _COMPONENT ACPI_HARDWARE |
| ACPI_MODULE_NAME ("hwtimer") |
| |
| |
| #if (!ACPI_REDUCED_HARDWARE) /* Entire module */ |
| /****************************************************************************** |
| * |
| * FUNCTION: AcpiGetTimerResolution |
| * |
| * PARAMETERS: Resolution - Where the resolution is returned |
| * |
| * RETURN: Status and timer resolution |
| * |
| * DESCRIPTION: Obtains resolution of the ACPI PM Timer (24 or 32 bits). |
| * |
| ******************************************************************************/ |
| |
| ACPI_STATUS |
| AcpiGetTimerResolution ( |
| UINT32 *Resolution) |
| { |
| ACPI_FUNCTION_TRACE (AcpiGetTimerResolution); |
| |
| |
| if (!Resolution) |
| { |
| return_ACPI_STATUS (AE_BAD_PARAMETER); |
| } |
| |
| if ((AcpiGbl_FADT.Flags & ACPI_FADT_32BIT_TIMER) == 0) |
| { |
| *Resolution = 24; |
| } |
| else |
| { |
| *Resolution = 32; |
| } |
| |
| return_ACPI_STATUS (AE_OK); |
| } |
| |
| ACPI_EXPORT_SYMBOL (AcpiGetTimerResolution) |
| |
| |
| /****************************************************************************** |
| * |
| * FUNCTION: AcpiGetTimer |
| * |
| * PARAMETERS: Ticks - Where the timer value is returned |
| * |
| * RETURN: Status and current timer value (ticks) |
| * |
| * DESCRIPTION: Obtains current value of ACPI PM Timer (in ticks). |
| * |
| ******************************************************************************/ |
| |
| ACPI_STATUS |
| AcpiGetTimer ( |
| UINT32 *Ticks) |
| { |
| ACPI_STATUS Status; |
| |
| |
| ACPI_FUNCTION_TRACE (AcpiGetTimer); |
| |
| |
| if (!Ticks) |
| { |
| return_ACPI_STATUS (AE_BAD_PARAMETER); |
| } |
| |
| /* ACPI 5.0A: PM Timer is optional */ |
| |
| if (!AcpiGbl_FADT.XPmTimerBlock.Address) |
| { |
| return_ACPI_STATUS (AE_SUPPORT); |
| } |
| |
| Status = AcpiHwRead (Ticks, &AcpiGbl_FADT.XPmTimerBlock); |
| return_ACPI_STATUS (Status); |
| } |
| |
| ACPI_EXPORT_SYMBOL (AcpiGetTimer) |
| |
| |
| /****************************************************************************** |
| * |
| * FUNCTION: AcpiGetTimerDuration |
| * |
| * PARAMETERS: StartTicks - Starting timestamp |
| * EndTicks - End timestamp |
| * TimeElapsed - Where the elapsed time is returned |
| * |
| * RETURN: Status and 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 accommodates 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 minutes for 32-bit timers) -- calculations below: |
| * |
| * 2**24 Ticks / 3,600,000 Ticks/Sec = 4.66 sec |
| * 2**32 Ticks / 3,600,000 Ticks/Sec = 1193 sec or 19.88 minutes |
| * |
| ******************************************************************************/ |
| |
| ACPI_STATUS |
| AcpiGetTimerDuration ( |
| UINT32 StartTicks, |
| UINT32 EndTicks, |
| UINT32 *TimeElapsed) |
| { |
| ACPI_STATUS Status; |
| UINT32 DeltaTicks; |
| UINT64 Quotient; |
| |
| |
| ACPI_FUNCTION_TRACE (AcpiGetTimerDuration); |
| |
| |
| if (!TimeElapsed) |
| { |
| return_ACPI_STATUS (AE_BAD_PARAMETER); |
| } |
| |
| /* ACPI 5.0A: PM Timer is optional */ |
| |
| if (!AcpiGbl_FADT.XPmTimerBlock.Address) |
| { |
| return_ACPI_STATUS (AE_SUPPORT); |
| } |
| |
| /* |
| * Compute Tick Delta: |
| * Handle (max one) timer rollovers on 24-bit versus 32-bit timers. |
| */ |
| if (StartTicks < EndTicks) |
| { |
| DeltaTicks = EndTicks - StartTicks; |
| } |
| else if (StartTicks > EndTicks) |
| { |
| if ((AcpiGbl_FADT.Flags & ACPI_FADT_32BIT_TIMER) == 0) |
| { |
| /* 24-bit Timer */ |
| |
| DeltaTicks = (((0x00FFFFFF - StartTicks) + EndTicks) & 0x00FFFFFF); |
| } |
| else |
| { |
| /* 32-bit Timer */ |
| |
| DeltaTicks = (0xFFFFFFFF - StartTicks) + EndTicks; |
| } |
| } |
| else /* StartTicks == EndTicks */ |
| { |
| *TimeElapsed = 0; |
| return_ACPI_STATUS (AE_OK); |
| } |
| |
| /* |
| * Compute Duration (Requires a 64-bit multiply and divide): |
| * |
| * TimeElapsed (microseconds) = |
| * (DeltaTicks * ACPI_USEC_PER_SEC) / ACPI_PM_TIMER_FREQUENCY; |
| */ |
| Status = AcpiUtShortDivide (((UINT64) DeltaTicks) * ACPI_USEC_PER_SEC, |
| ACPI_PM_TIMER_FREQUENCY, &Quotient, NULL); |
| |
| *TimeElapsed = (UINT32) Quotient; |
| return_ACPI_STATUS (Status); |
| } |
| |
| ACPI_EXPORT_SYMBOL (AcpiGetTimerDuration) |
| |
| #endif /* !ACPI_REDUCED_HARDWARE */ |
