hwtimer.c revision 99679
1218885Sdim 2218885Sdim/****************************************************************************** 3218885Sdim * 4218885Sdim * Name: hwtimer.c - ACPI Power Management Timer Interface 5218885Sdim * $Revision: 21 $ 6218885Sdim * 7218885Sdim *****************************************************************************/ 8218885Sdim 9218885Sdim/****************************************************************************** 10218885Sdim * 11218885Sdim * 1. Copyright Notice 12218885Sdim * 13218885Sdim * Some or all of this work - Copyright (c) 1999 - 2002, Intel Corp. 14218885Sdim * All rights reserved. 15218885Sdim * 16218885Sdim * 2. License 17218885Sdim * 18218885Sdim * 2.1. This is your license from Intel Corp. under its intellectual property 19276479Sdim * rights. You may have additional license terms from the party that provided 20218885Sdim * you this software, covering your right to use that party's intellectual 21218885Sdim * property rights. 22218885Sdim * 23218885Sdim * 2.2. Intel grants, free of charge, to any person ("Licensee") obtaining a 24226633Sdim * copy of the source code appearing in this file ("Covered Code") an 25226633Sdim * irrevocable, perpetual, worldwide license under Intel's copyrights in the 26226633Sdim * base code distributed originally by Intel ("Original Intel Code") to copy, 27226633Sdim * make derivatives, distribute, use and display any portion of the Covered 28226633Sdim * Code in any form, with the right to sublicense such rights; and 29226633Sdim * 30226633Sdim * 2.3. Intel grants Licensee a non-exclusive and non-transferable patent 31226633Sdim * license (with the right to sublicense), under only those claims of Intel 32226633Sdim * patents that are infringed by the Original Intel Code, to make, use, sell, 33226633Sdim * offer to sell, and import the Covered Code and derivative works thereof 34226633Sdim * solely to the minimum extent necessary to exercise the above copyright 35226633Sdim * license, and in no event shall the patent license extend to any additions 36226633Sdim * to or modifications of the Original Intel Code. No other license or right 37226633Sdim * is granted directly or by implication, estoppel or otherwise; 38226633Sdim * 39226633Sdim * The above copyright and patent license is granted only if the following 40226633Sdim * conditions are met: 41226633Sdim * 42226633Sdim * 3. Conditions 43226633Sdim * 44226633Sdim * 3.1. Redistribution of Source with Rights to Further Distribute Source. 45226633Sdim * Redistribution of source code of any substantial portion of the Covered 46226633Sdim * Code or modification with rights to further distribute source must include 47226633Sdim * the above Copyright Notice, the above License, this list of Conditions, 48226633Sdim * and the following Disclaimer and Export Compliance provision. In addition, 49226633Sdim * Licensee must cause all Covered Code to which Licensee contributes to 50226633Sdim * contain a file documenting the changes Licensee made to create that Covered 51261991Sdim * Code and the date of any change. Licensee must include in that file the 52226633Sdim * documentation of any changes made by any predecessor Licensee. Licensee 53226633Sdim * must include a prominent statement that the modification is derived, 54226633Sdim * directly or indirectly, from Original Intel Code. 55226633Sdim * 56226633Sdim * 3.2. Redistribution of Source with no Rights to Further Distribute Source. 57226633Sdim * Redistribution of source code of any substantial portion of the Covered 58226633Sdim * Code or modification without rights to further distribute source must 59226633Sdim * include the following Disclaimer and Export Compliance provision in the 60226633Sdim * documentation and/or other materials provided with distribution. In 61226633Sdim * addition, Licensee may not authorize further sublicense of source of any 62226633Sdim * portion of the Covered Code, and must include terms to the effect that the 63226633Sdim * license from Licensee to its licensee is limited to the intellectual 64226633Sdim * property embodied in the software Licensee provides to its licensee, and 65226633Sdim * not to intellectual property embodied in modifications its licensee may 66226633Sdim * make. 67226633Sdim * 68239462Sdim * 3.3. Redistribution of Executable. Redistribution in executable form of any 69239462Sdim * substantial portion of the Covered Code or modification must reproduce the 70239462Sdim * above Copyright Notice, and the following Disclaimer and Export Compliance 71226633Sdim * provision in the documentation and/or other materials provided with the 72226633Sdim * distribution. 73226633Sdim * 74226633Sdim * 3.4. Intel retains all right, title, and interest in and to the Original 75226633Sdim * Intel Code. 76218885Sdim * 77226633Sdim * 3.5. Neither the name Intel nor any other trademark owned or controlled by 78226633Sdim * Intel shall be used in advertising or otherwise to promote the sale, use or 79226633Sdim * other dealings in products derived from or relating to the Covered Code 80226633Sdim * without prior written authorization from Intel. 81226633Sdim * 82226633Sdim * 4. Disclaimer and Export Compliance 83226633Sdim * 84218885Sdim * 4.1. INTEL MAKES NO WARRANTY OF ANY KIND REGARDING ANY SOFTWARE PROVIDED 85218885Sdim * HERE. ANY SOFTWARE ORIGINATING FROM INTEL OR DERIVED FROM INTEL SOFTWARE 86218885Sdim * IS PROVIDED "AS IS," AND INTEL WILL NOT PROVIDE ANY SUPPORT, ASSISTANCE, 87280031Sdim * INSTALLATION, TRAINING OR OTHER SERVICES. INTEL WILL NOT PROVIDE ANY 88226633Sdim * UPDATES, ENHANCEMENTS OR EXTENSIONS. INTEL SPECIFICALLY DISCLAIMS ANY 89280031Sdim * IMPLIED WARRANTIES OF MERCHANTABILITY, NONINFRINGEMENT AND FITNESS FOR A 90280031Sdim * PARTICULAR PURPOSE. 91218885Sdim * 92218885Sdim * 4.2. IN NO EVENT SHALL INTEL HAVE ANY LIABILITY TO LICENSEE, ITS LICENSEES 93218885Sdim * OR ANY OTHER THIRD PARTY, FOR ANY LOST PROFITS, LOST DATA, LOSS OF USE OR 94226633Sdim * COSTS OF PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES, OR FOR ANY INDIRECT, 95226633Sdim * SPECIAL OR CONSEQUENTIAL DAMAGES ARISING OUT OF THIS AGREEMENT, UNDER ANY 96226633Sdim * CAUSE OF ACTION OR THEORY OF LIABILITY, AND IRRESPECTIVE OF WHETHER INTEL 97226633Sdim * HAS ADVANCE NOTICE OF THE POSSIBILITY OF SUCH DAMAGES. THESE LIMITATIONS 98226633Sdim * SHALL APPLY NOTWITHSTANDING THE FAILURE OF THE ESSENTIAL PURPOSE OF ANY 99218885Sdim * LIMITED REMEDY. 100218885Sdim * 101218885Sdim * 4.3. Licensee shall not export, either directly or indirectly, any of this 102218885Sdim * software or system incorporating such software without first obtaining any 103226633Sdim * required license or other approval from the U. S. Department of Commerce or 104226633Sdim * any other agency or department of the United States Government. In the 105226633Sdim * event Licensee exports any such software from the United States or 106226633Sdim * re-exports any such software from a foreign destination, Licensee shall 107226633Sdim * ensure that the distribution and export/re-export of the software is in 108218885Sdim * compliance with all laws, regulations, orders, or other restrictions of the 109218885Sdim * U.S. Export Administration Regulations. Licensee agrees that neither it nor 110218885Sdim * any of its subsidiaries will export/re-export any technical data, process, 111218885Sdim * software, or service, directly or indirectly, to any country for which the 112226633Sdim * United States government or any agency thereof requires an export license, 113226633Sdim * other governmental approval, or letter of assurance, without first obtaining 114226633Sdim * such license, approval or letter. 115226633Sdim * 116226633Sdim *****************************************************************************/ 117218885Sdim 118218885Sdim#include "acpi.h" 119218885Sdim 120218885Sdim#define _COMPONENT ACPI_HARDWARE 121226633Sdim ACPI_MODULE_NAME ("hwtimer") 122226633Sdim 123226633Sdim 124226633Sdim/****************************************************************************** 125226633Sdim * 126218885Sdim * FUNCTION: AcpiGetTimerResolution 127218885Sdim * 128218885Sdim * PARAMETERS: none 129218885Sdim * 130218885Sdim * RETURN: Number of bits of resolution in the PM Timer (24 or 32). 131 * 132 * DESCRIPTION: Obtains resolution of the ACPI PM Timer. 133 * 134 ******************************************************************************/ 135 136ACPI_STATUS 137AcpiGetTimerResolution ( 138 UINT32 *Resolution) 139{ 140 ACPI_FUNCTION_TRACE ("AcpiGetTimerResolution"); 141 142 143 if (!Resolution) 144 { 145 return_ACPI_STATUS (AE_BAD_PARAMETER); 146 } 147 148 if (0 == AcpiGbl_FADT->TmrValExt) 149 { 150 *Resolution = 24; 151 } 152 else 153 { 154 *Resolution = 32; 155 } 156 157 return_ACPI_STATUS (AE_OK); 158} 159 160 161/****************************************************************************** 162 * 163 * FUNCTION: AcpiGetTimer 164 * 165 * PARAMETERS: none 166 * 167 * RETURN: Current value of the ACPI PM Timer (in ticks). 168 * 169 * DESCRIPTION: Obtains current value of ACPI PM Timer. 170 * 171 ******************************************************************************/ 172 173ACPI_STATUS 174AcpiGetTimer ( 175 UINT32 *Ticks) 176{ 177 ACPI_STATUS Status; 178 179 180 ACPI_FUNCTION_TRACE ("AcpiGetTimer"); 181 182 183 if (!Ticks) 184 { 185 return_ACPI_STATUS (AE_BAD_PARAMETER); 186 } 187 188 Status = AcpiHwLowLevelRead (32, Ticks, &AcpiGbl_FADT->XPmTmrBlk, 0); 189 190 return_ACPI_STATUS (Status); 191} 192 193 194/****************************************************************************** 195 * 196 * FUNCTION: AcpiGetTimerDuration 197 * 198 * PARAMETERS: StartTicks 199 * EndTicks 200 * TimeElapsed 201 * 202 * RETURN: TimeElapsed 203 * 204 * DESCRIPTION: Computes the time elapsed (in microseconds) between two 205 * PM Timer time stamps, taking into account the possibility of 206 * rollovers, the timer resolution, and timer frequency. 207 * 208 * The PM Timer's clock ticks at roughly 3.6 times per 209 * _microsecond_, and its clock continues through Cx state 210 * transitions (unlike many CPU timestamp counters) -- making it 211 * a versatile and accurate timer. 212 * 213 * Note that this function accomodates only a single timer 214 * rollover. Thus for 24-bit timers, this function should only 215 * be used for calculating durations less than ~4.6 seconds 216 * (~20 hours for 32-bit timers). 217 * 218 ******************************************************************************/ 219 220ACPI_STATUS 221AcpiGetTimerDuration ( 222 UINT32 StartTicks, 223 UINT32 EndTicks, 224 UINT32 *TimeElapsed) 225{ 226 UINT32 DeltaTicks = 0; 227 UINT64_OVERLAY NormalizedTicks; 228 ACPI_STATUS Status; 229 ACPI_INTEGER OutQuotient; 230 231 232 ACPI_FUNCTION_TRACE ("AcpiGetTimerDuration"); 233 234 235 if (!TimeElapsed) 236 { 237 return_ACPI_STATUS (AE_BAD_PARAMETER); 238 } 239 240 /* 241 * Compute Tick Delta: 242 * ------------------- 243 * Handle (max one) timer rollovers on 24- versus 32-bit timers. 244 */ 245 if (StartTicks < EndTicks) 246 { 247 DeltaTicks = EndTicks - StartTicks; 248 } 249 else if (StartTicks > EndTicks) 250 { 251 if (0 == AcpiGbl_FADT->TmrValExt) 252 { 253 /* 24-bit Timer */ 254 255 DeltaTicks = (((0x00FFFFFF - StartTicks) + EndTicks) & 0x00FFFFFF); 256 } 257 else 258 { 259 /* 32-bit Timer */ 260 261 DeltaTicks = (0xFFFFFFFF - StartTicks) + EndTicks; 262 } 263 } 264 else 265 { 266 *TimeElapsed = 0; 267 return_ACPI_STATUS (AE_OK); 268 } 269 270 /* 271 * Compute Duration: 272 * ----------------- 273 * 274 * Requires a 64-bit divide: 275 * 276 * TimeElapsed = (DeltaTicks * 1000000) / PM_TIMER_FREQUENCY; 277 */ 278 NormalizedTicks.Full = ((UINT64) DeltaTicks) * 1000000; 279 280 Status = AcpiUtShortDivide (&NormalizedTicks.Full, PM_TIMER_FREQUENCY, 281 &OutQuotient, NULL); 282 283 *TimeElapsed = (UINT32) OutQuotient; 284 return_ACPI_STATUS (Status); 285} 286 287 288