195857638SErik Schmauss // SPDX-License-Identifier: BSD-3-Clause OR GPL-2.0 295b482a8SLen Brown /****************************************************************************** 395b482a8SLen Brown * 495b482a8SLen Brown * Name: hwtimer.c - ACPI Power Management Timer Interface 595b482a8SLen Brown * 6da6f8320SBob Moore * Copyright (C) 2000 - 2018, Intel Corp. 795b482a8SLen Brown * 895857638SErik Schmauss *****************************************************************************/ 995b482a8SLen Brown 10839e928fSLv Zheng #define EXPORT_ACPI_INTERFACES 11839e928fSLv Zheng 1295b482a8SLen Brown #include <acpi/acpi.h> 13e2f7a777SLen Brown #include "accommon.h" 1495b482a8SLen Brown 1595b482a8SLen Brown #define _COMPONENT ACPI_HARDWARE 1695b482a8SLen Brown ACPI_MODULE_NAME("hwtimer") 1795b482a8SLen Brown 1833620c54SBob Moore #if (!ACPI_REDUCED_HARDWARE) /* Entire module */ 1995b482a8SLen Brown /****************************************************************************** 2095b482a8SLen Brown * 2195b482a8SLen Brown * FUNCTION: acpi_get_timer_resolution 2295b482a8SLen Brown * 23ba494beeSBob Moore * PARAMETERS: resolution - Where the resolution is returned 2495b482a8SLen Brown * 2595b482a8SLen Brown * RETURN: Status and timer resolution 2695b482a8SLen Brown * 2795b482a8SLen Brown * DESCRIPTION: Obtains resolution of the ACPI PM Timer (24 or 32 bits). 2895b482a8SLen Brown * 2995b482a8SLen Brown ******************************************************************************/ 3095b482a8SLen Brown acpi_status acpi_get_timer_resolution(u32 * resolution) 3195b482a8SLen Brown { 3295b482a8SLen Brown ACPI_FUNCTION_TRACE(acpi_get_timer_resolution); 3395b482a8SLen Brown 3495b482a8SLen Brown if (!resolution) { 3595b482a8SLen Brown return_ACPI_STATUS(AE_BAD_PARAMETER); 3695b482a8SLen Brown } 3795b482a8SLen Brown 3895b482a8SLen Brown if ((acpi_gbl_FADT.flags & ACPI_FADT_32BIT_TIMER) == 0) { 3995b482a8SLen Brown *resolution = 24; 4095b482a8SLen Brown } else { 4195b482a8SLen Brown *resolution = 32; 4295b482a8SLen Brown } 4395b482a8SLen Brown 4495b482a8SLen Brown return_ACPI_STATUS(AE_OK); 4595b482a8SLen Brown } 4695b482a8SLen Brown 4795b482a8SLen Brown ACPI_EXPORT_SYMBOL(acpi_get_timer_resolution) 4895b482a8SLen Brown 4995b482a8SLen Brown /****************************************************************************** 5095b482a8SLen Brown * 5195b482a8SLen Brown * FUNCTION: acpi_get_timer 5295b482a8SLen Brown * 53ba494beeSBob Moore * PARAMETERS: ticks - Where the timer value is returned 5495b482a8SLen Brown * 5595b482a8SLen Brown * RETURN: Status and current timer value (ticks) 5695b482a8SLen Brown * 5795b482a8SLen Brown * DESCRIPTION: Obtains current value of ACPI PM Timer (in ticks). 5895b482a8SLen Brown * 5995b482a8SLen Brown ******************************************************************************/ 6095b482a8SLen Brown acpi_status acpi_get_timer(u32 * ticks) 6195b482a8SLen Brown { 6295b482a8SLen Brown acpi_status status; 638092936dSBob Moore u64 timer_value; 6495b482a8SLen Brown 6595b482a8SLen Brown ACPI_FUNCTION_TRACE(acpi_get_timer); 6695b482a8SLen Brown 6795b482a8SLen Brown if (!ticks) { 6895b482a8SLen Brown return_ACPI_STATUS(AE_BAD_PARAMETER); 6995b482a8SLen Brown } 7095b482a8SLen Brown 711d82980cSBob Moore /* ACPI 5.0A: PM Timer is optional */ 7295b482a8SLen Brown 731d82980cSBob Moore if (!acpi_gbl_FADT.xpm_timer_block.address) { 741d82980cSBob Moore return_ACPI_STATUS(AE_SUPPORT); 751d82980cSBob Moore } 761d82980cSBob Moore 778092936dSBob Moore status = acpi_hw_read(&timer_value, &acpi_gbl_FADT.xpm_timer_block); 788092936dSBob Moore if (ACPI_SUCCESS(status)) { 798092936dSBob Moore 808092936dSBob Moore /* ACPI PM Timer is defined to be 32 bits (PM_TMR_LEN) */ 818092936dSBob Moore 828092936dSBob Moore *ticks = (u32)timer_value; 838092936dSBob Moore } 848092936dSBob Moore 8595b482a8SLen Brown return_ACPI_STATUS(status); 8695b482a8SLen Brown } 8795b482a8SLen Brown 8895b482a8SLen Brown ACPI_EXPORT_SYMBOL(acpi_get_timer) 8995b482a8SLen Brown 9095b482a8SLen Brown /****************************************************************************** 9195b482a8SLen Brown * 9295b482a8SLen Brown * FUNCTION: acpi_get_timer_duration 9395b482a8SLen Brown * 9495b482a8SLen Brown * PARAMETERS: start_ticks - Starting timestamp 9595b482a8SLen Brown * end_ticks - End timestamp 9695b482a8SLen Brown * time_elapsed - Where the elapsed time is returned 9795b482a8SLen Brown * 9895b482a8SLen Brown * RETURN: Status and time_elapsed 9995b482a8SLen Brown * 10095b482a8SLen Brown * DESCRIPTION: Computes the time elapsed (in microseconds) between two 10195b482a8SLen Brown * PM Timer time stamps, taking into account the possibility of 10295b482a8SLen Brown * rollovers, the timer resolution, and timer frequency. 10395b482a8SLen Brown * 10495b482a8SLen Brown * The PM Timer's clock ticks at roughly 3.6 times per 10595b482a8SLen Brown * _microsecond_, and its clock continues through Cx state 10695b482a8SLen Brown * transitions (unlike many CPU timestamp counters) -- making it 10795b482a8SLen Brown * a versatile and accurate timer. 10895b482a8SLen Brown * 10995b482a8SLen Brown * Note that this function accommodates only a single timer 11095b482a8SLen Brown * rollover. Thus for 24-bit timers, this function should only 11195b482a8SLen Brown * be used for calculating durations less than ~4.6 seconds 11295b482a8SLen Brown * (~20 minutes for 32-bit timers) -- calculations below: 11395b482a8SLen Brown * 11495b482a8SLen Brown * 2**24 Ticks / 3,600,000 Ticks/Sec = 4.66 sec 11595b482a8SLen Brown * 2**32 Ticks / 3,600,000 Ticks/Sec = 1193 sec or 19.88 minutes 11695b482a8SLen Brown * 11795b482a8SLen Brown ******************************************************************************/ 11895b482a8SLen Brown acpi_status 11995b482a8SLen Brown acpi_get_timer_duration(u32 start_ticks, u32 end_ticks, u32 *time_elapsed) 12095b482a8SLen Brown { 12195b482a8SLen Brown acpi_status status; 1228f275615SJung-uk Kim u64 delta_ticks; 1235df7e6cbSBob Moore u64 quotient; 12495b482a8SLen Brown 12595b482a8SLen Brown ACPI_FUNCTION_TRACE(acpi_get_timer_duration); 12695b482a8SLen Brown 12795b482a8SLen Brown if (!time_elapsed) { 12895b482a8SLen Brown return_ACPI_STATUS(AE_BAD_PARAMETER); 12995b482a8SLen Brown } 13095b482a8SLen Brown 1311d82980cSBob Moore /* ACPI 5.0A: PM Timer is optional */ 1321d82980cSBob Moore 1331d82980cSBob Moore if (!acpi_gbl_FADT.xpm_timer_block.address) { 1341d82980cSBob Moore return_ACPI_STATUS(AE_SUPPORT); 1351d82980cSBob Moore } 1361d82980cSBob Moore 1378f275615SJung-uk Kim if (start_ticks == end_ticks) { 1388f275615SJung-uk Kim *time_elapsed = 0; 1398f275615SJung-uk Kim return_ACPI_STATUS(AE_OK); 1408f275615SJung-uk Kim } 1418f275615SJung-uk Kim 14295b482a8SLen Brown /* 14395b482a8SLen Brown * Compute Tick Delta: 14495b482a8SLen Brown * Handle (max one) timer rollovers on 24-bit versus 32-bit timers. 14595b482a8SLen Brown */ 1468f275615SJung-uk Kim delta_ticks = end_ticks; 1478f275615SJung-uk Kim if (start_ticks > end_ticks) { 14895b482a8SLen Brown if ((acpi_gbl_FADT.flags & ACPI_FADT_32BIT_TIMER) == 0) { 14995b482a8SLen Brown 15095b482a8SLen Brown /* 24-bit Timer */ 15195b482a8SLen Brown 1528f275615SJung-uk Kim delta_ticks |= (u64)1 << 24; 15395b482a8SLen Brown } else { 15495b482a8SLen Brown /* 32-bit Timer */ 15595b482a8SLen Brown 1568f275615SJung-uk Kim delta_ticks |= (u64)1 << 32; 15795b482a8SLen Brown } 15895b482a8SLen Brown } 1598f275615SJung-uk Kim delta_ticks -= start_ticks; 16095b482a8SLen Brown 16195b482a8SLen Brown /* 16295b482a8SLen Brown * Compute Duration (Requires a 64-bit multiply and divide): 16395b482a8SLen Brown * 164c41679a4SBob Moore * time_elapsed (microseconds) = 165c41679a4SBob Moore * (delta_ticks * ACPI_USEC_PER_SEC) / ACPI_PM_TIMER_FREQUENCY; 16695b482a8SLen Brown */ 1678f275615SJung-uk Kim status = acpi_ut_short_divide(delta_ticks * ACPI_USEC_PER_SEC, 168c41679a4SBob Moore ACPI_PM_TIMER_FREQUENCY, "ient, NULL); 16995b482a8SLen Brown 17095b482a8SLen Brown *time_elapsed = (u32)quotient; 17195b482a8SLen Brown return_ACPI_STATUS(status); 17295b482a8SLen Brown } 17395b482a8SLen Brown 17495b482a8SLen Brown ACPI_EXPORT_SYMBOL(acpi_get_timer_duration) 17533620c54SBob Moore #endif /* !ACPI_REDUCED_HARDWARE */ 176