Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1 | |
| 2 | /****************************************************************************** |
| 3 | * |
| 4 | * Name: hwtimer.c - ACPI Power Management Timer Interface |
| 5 | * |
| 6 | *****************************************************************************/ |
| 7 | |
| 8 | /* |
Bob Moore | 6c9deb7 | 2007-02-02 19:48:24 +0300 | [diff] [blame] | 9 | * Copyright (C) 2000 - 2007, R. Byron Moore |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 10 | * All rights reserved. |
| 11 | * |
| 12 | * Redistribution and use in source and binary forms, with or without |
| 13 | * modification, are permitted provided that the following conditions |
| 14 | * are met: |
| 15 | * 1. Redistributions of source code must retain the above copyright |
| 16 | * notice, this list of conditions, and the following disclaimer, |
| 17 | * without modification. |
| 18 | * 2. Redistributions in binary form must reproduce at minimum a disclaimer |
| 19 | * substantially similar to the "NO WARRANTY" disclaimer below |
| 20 | * ("Disclaimer") and any redistribution must be conditioned upon |
| 21 | * including a substantially similar Disclaimer requirement for further |
| 22 | * binary redistribution. |
| 23 | * 3. Neither the names of the above-listed copyright holders nor the names |
| 24 | * of any contributors may be used to endorse or promote products derived |
| 25 | * from this software without specific prior written permission. |
| 26 | * |
| 27 | * Alternatively, this software may be distributed under the terms of the |
| 28 | * GNU General Public License ("GPL") version 2 as published by the Free |
| 29 | * Software Foundation. |
| 30 | * |
| 31 | * NO WARRANTY |
| 32 | * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS |
| 33 | * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT |
| 34 | * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTIBILITY AND FITNESS FOR |
| 35 | * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT |
| 36 | * HOLDERS OR CONTRIBUTORS BE LIABLE FOR SPECIAL, EXEMPLARY, OR CONSEQUENTIAL |
| 37 | * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS |
| 38 | * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) |
| 39 | * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, |
| 40 | * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING |
| 41 | * IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE |
| 42 | * POSSIBILITY OF SUCH DAMAGES. |
| 43 | */ |
| 44 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 45 | #include <acpi/acpi.h> |
| 46 | |
| 47 | #define _COMPONENT ACPI_HARDWARE |
Len Brown | 4be44fc | 2005-08-05 00:44:28 -0400 | [diff] [blame] | 48 | ACPI_MODULE_NAME("hwtimer") |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 49 | |
| 50 | /****************************************************************************** |
| 51 | * |
| 52 | * FUNCTION: acpi_get_timer_resolution |
| 53 | * |
| 54 | * PARAMETERS: Resolution - Where the resolution is returned |
| 55 | * |
| 56 | * RETURN: Status and timer resolution |
| 57 | * |
| 58 | * DESCRIPTION: Obtains resolution of the ACPI PM Timer (24 or 32 bits). |
| 59 | * |
| 60 | ******************************************************************************/ |
Len Brown | 4be44fc | 2005-08-05 00:44:28 -0400 | [diff] [blame] | 61 | acpi_status acpi_get_timer_resolution(u32 * resolution) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 62 | { |
Bob Moore | b229cf9 | 2006-04-21 17:15:00 -0400 | [diff] [blame] | 63 | ACPI_FUNCTION_TRACE(acpi_get_timer_resolution); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 64 | |
| 65 | if (!resolution) { |
Len Brown | 4be44fc | 2005-08-05 00:44:28 -0400 | [diff] [blame] | 66 | return_ACPI_STATUS(AE_BAD_PARAMETER); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 67 | } |
| 68 | |
Bob Moore | f3d2e78 | 2007-02-02 19:48:18 +0300 | [diff] [blame] | 69 | if ((acpi_gbl_FADT.flags & ACPI_FADT_32BIT_TIMER) == 0) { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 70 | *resolution = 24; |
Len Brown | 4be44fc | 2005-08-05 00:44:28 -0400 | [diff] [blame] | 71 | } else { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 72 | *resolution = 32; |
| 73 | } |
| 74 | |
Len Brown | 4be44fc | 2005-08-05 00:44:28 -0400 | [diff] [blame] | 75 | return_ACPI_STATUS(AE_OK); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 76 | } |
| 77 | |
Bob Moore | 8313524 | 2006-10-03 00:00:00 -0400 | [diff] [blame] | 78 | ACPI_EXPORT_SYMBOL(acpi_get_timer_resolution) |
| 79 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 80 | /****************************************************************************** |
| 81 | * |
| 82 | * FUNCTION: acpi_get_timer |
| 83 | * |
| 84 | * PARAMETERS: Ticks - Where the timer value is returned |
| 85 | * |
Robert Moore | 44f6c01 | 2005-04-18 22:49:35 -0400 | [diff] [blame] | 86 | * RETURN: Status and current timer value (ticks) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 87 | * |
| 88 | * DESCRIPTION: Obtains current value of ACPI PM Timer (in ticks). |
| 89 | * |
| 90 | ******************************************************************************/ |
Len Brown | 4be44fc | 2005-08-05 00:44:28 -0400 | [diff] [blame] | 91 | acpi_status acpi_get_timer(u32 * ticks) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 92 | { |
Len Brown | 4be44fc | 2005-08-05 00:44:28 -0400 | [diff] [blame] | 93 | acpi_status status; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 94 | |
Bob Moore | b229cf9 | 2006-04-21 17:15:00 -0400 | [diff] [blame] | 95 | ACPI_FUNCTION_TRACE(acpi_get_timer); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 96 | |
| 97 | if (!ticks) { |
Len Brown | 4be44fc | 2005-08-05 00:44:28 -0400 | [diff] [blame] | 98 | return_ACPI_STATUS(AE_BAD_PARAMETER); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 99 | } |
| 100 | |
Bob Moore | f3d2e78 | 2007-02-02 19:48:18 +0300 | [diff] [blame] | 101 | status = |
| 102 | acpi_hw_low_level_read(32, ticks, &acpi_gbl_FADT.xpm_timer_block); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 103 | |
Len Brown | 4be44fc | 2005-08-05 00:44:28 -0400 | [diff] [blame] | 104 | return_ACPI_STATUS(status); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 105 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 106 | |
Bob Moore | 8313524 | 2006-10-03 00:00:00 -0400 | [diff] [blame] | 107 | ACPI_EXPORT_SYMBOL(acpi_get_timer) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 108 | |
| 109 | /****************************************************************************** |
| 110 | * |
| 111 | * FUNCTION: acpi_get_timer_duration |
| 112 | * |
| 113 | * PARAMETERS: start_ticks - Starting timestamp |
| 114 | * end_ticks - End timestamp |
| 115 | * time_elapsed - Where the elapsed time is returned |
| 116 | * |
| 117 | * RETURN: Status and time_elapsed |
| 118 | * |
| 119 | * DESCRIPTION: Computes the time elapsed (in microseconds) between two |
| 120 | * PM Timer time stamps, taking into account the possibility of |
| 121 | * rollovers, the timer resolution, and timer frequency. |
| 122 | * |
| 123 | * The PM Timer's clock ticks at roughly 3.6 times per |
| 124 | * _microsecond_, and its clock continues through Cx state |
| 125 | * transitions (unlike many CPU timestamp counters) -- making it |
| 126 | * a versatile and accurate timer. |
| 127 | * |
| 128 | * Note that this function accommodates only a single timer |
| 129 | * rollover. Thus for 24-bit timers, this function should only |
| 130 | * be used for calculating durations less than ~4.6 seconds |
| 131 | * (~20 minutes for 32-bit timers) -- calculations below: |
| 132 | * |
| 133 | * 2**24 Ticks / 3,600,000 Ticks/Sec = 4.66 sec |
| 134 | * 2**32 Ticks / 3,600,000 Ticks/Sec = 1193 sec or 19.88 minutes |
| 135 | * |
| 136 | ******************************************************************************/ |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 137 | acpi_status |
Len Brown | 4be44fc | 2005-08-05 00:44:28 -0400 | [diff] [blame] | 138 | acpi_get_timer_duration(u32 start_ticks, u32 end_ticks, u32 * time_elapsed) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 139 | { |
Len Brown | 4be44fc | 2005-08-05 00:44:28 -0400 | [diff] [blame] | 140 | acpi_status status; |
| 141 | u32 delta_ticks; |
| 142 | acpi_integer quotient; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 143 | |
Bob Moore | b229cf9 | 2006-04-21 17:15:00 -0400 | [diff] [blame] | 144 | ACPI_FUNCTION_TRACE(acpi_get_timer_duration); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 145 | |
| 146 | if (!time_elapsed) { |
Len Brown | 4be44fc | 2005-08-05 00:44:28 -0400 | [diff] [blame] | 147 | return_ACPI_STATUS(AE_BAD_PARAMETER); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 148 | } |
| 149 | |
| 150 | /* |
| 151 | * Compute Tick Delta: |
| 152 | * Handle (max one) timer rollovers on 24-bit versus 32-bit timers. |
| 153 | */ |
| 154 | if (start_ticks < end_ticks) { |
| 155 | delta_ticks = end_ticks - start_ticks; |
Len Brown | 4be44fc | 2005-08-05 00:44:28 -0400 | [diff] [blame] | 156 | } else if (start_ticks > end_ticks) { |
Bob Moore | f3d2e78 | 2007-02-02 19:48:18 +0300 | [diff] [blame] | 157 | if ((acpi_gbl_FADT.flags & ACPI_FADT_32BIT_TIMER) == 0) { |
Bob Moore | 52fc0b0 | 2006-10-02 00:00:00 -0400 | [diff] [blame] | 158 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 159 | /* 24-bit Timer */ |
| 160 | |
Len Brown | 4be44fc | 2005-08-05 00:44:28 -0400 | [diff] [blame] | 161 | delta_ticks = |
| 162 | (((0x00FFFFFF - start_ticks) + |
| 163 | end_ticks) & 0x00FFFFFF); |
| 164 | } else { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 165 | /* 32-bit Timer */ |
| 166 | |
| 167 | delta_ticks = (0xFFFFFFFF - start_ticks) + end_ticks; |
| 168 | } |
Len Brown | 4be44fc | 2005-08-05 00:44:28 -0400 | [diff] [blame] | 169 | } else { /* start_ticks == end_ticks */ |
| 170 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 171 | *time_elapsed = 0; |
Len Brown | 4be44fc | 2005-08-05 00:44:28 -0400 | [diff] [blame] | 172 | return_ACPI_STATUS(AE_OK); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 173 | } |
| 174 | |
| 175 | /* |
| 176 | * Compute Duration (Requires a 64-bit multiply and divide): |
| 177 | * |
| 178 | * time_elapsed = (delta_ticks * 1000000) / PM_TIMER_FREQUENCY; |
| 179 | */ |
Len Brown | 4be44fc | 2005-08-05 00:44:28 -0400 | [diff] [blame] | 180 | status = acpi_ut_short_divide(((u64) delta_ticks) * 1000000, |
| 181 | PM_TIMER_FREQUENCY, "ient, NULL); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 182 | |
| 183 | *time_elapsed = (u32) quotient; |
Len Brown | 4be44fc | 2005-08-05 00:44:28 -0400 | [diff] [blame] | 184 | return_ACPI_STATUS(status); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 185 | } |
Robert Moore | 44f6c01 | 2005-04-18 22:49:35 -0400 | [diff] [blame] | 186 | |
Bob Moore | 8313524 | 2006-10-03 00:00:00 -0400 | [diff] [blame] | 187 | ACPI_EXPORT_SYMBOL(acpi_get_timer_duration) |