1 2 /****************************************************************************** 3 * 4 * Name: hwtimer.c - ACPI Power Management Timer Interface 5 * 6 *****************************************************************************/ 7 8 /****************************************************************************** 9 * 10 * 1. Copyright Notice 11 * 12 * Some or all of this work - Copyright (c) 1999 - 2009, Intel Corp. 13 * All rights reserved. 14 * 15 * 2. License 16 * 17 * 2.1. This is your license from Intel Corp. under its intellectual property 18 * rights. You may have additional license terms from the party that provided 19 * you this software, covering your right to use that party's intellectual 20 * property rights. 21 * 22 * 2.2. Intel grants, free of charge, to any person ("Licensee") obtaining a 23 * copy of the source code appearing in this file ("Covered Code") an 24 * irrevocable, perpetual, worldwide license under Intel's copyrights in the 25 * base code distributed originally by Intel ("Original Intel Code") to copy, 26 * make derivatives, distribute, use and display any portion of the Covered 27 * Code in any form, with the right to sublicense such rights; and 28 * 29 * 2.3. Intel grants Licensee a non-exclusive and non-transferable patent 30 * license (with the right to sublicense), under only those claims of Intel 31 * patents that are infringed by the Original Intel Code, to make, use, sell, 32 * offer to sell, and import the Covered Code and derivative works thereof 33 * solely to the minimum extent necessary to exercise the above copyright 34 * license, and in no event shall the patent license extend to any additions 35 * to or modifications of the Original Intel Code. No other license or right 36 * is granted directly or by implication, estoppel or otherwise; 37 * 38 * The above copyright and patent license is granted only if the following 39 * conditions are met: 40 * 41 * 3. Conditions 42 * 43 * 3.1. Redistribution of Source with Rights to Further Distribute Source. 44 * Redistribution of source code of any substantial portion of the Covered 45 * Code or modification with rights to further distribute source must include 46 * the above Copyright Notice, the above License, this list of Conditions, 47 * and the following Disclaimer and Export Compliance provision. In addition, 48 * Licensee must cause all Covered Code to which Licensee contributes to 49 * contain a file documenting the changes Licensee made to create that Covered 50 * Code and the date of any change. Licensee must include in that file the 51 * documentation of any changes made by any predecessor Licensee. Licensee 52 * must include a prominent statement that the modification is derived, 53 * directly or indirectly, from Original Intel Code. 54 * 55 * 3.2. Redistribution of Source with no Rights to Further Distribute Source. 56 * Redistribution of source code of any substantial portion of the Covered 57 * Code or modification without rights to further distribute source must 58 * include the following Disclaimer and Export Compliance provision in the 59 * documentation and/or other materials provided with distribution. In 60 * addition, Licensee may not authorize further sublicense of source of any 61 * portion of the Covered Code, and must include terms to the effect that the 62 * license from Licensee to its licensee is limited to the intellectual 63 * property embodied in the software Licensee provides to its licensee, and 64 * not to intellectual property embodied in modifications its licensee may 65 * make. 66 * 67 * 3.3. Redistribution of Executable. Redistribution in executable form of any 68 * substantial portion of the Covered Code or modification must reproduce the 69 * above Copyright Notice, and the following Disclaimer and Export Compliance 70 * provision in the documentation and/or other materials provided with the 71 * distribution. 72 * 73 * 3.4. Intel retains all right, title, and interest in and to the Original 74 * Intel Code. 75 * 76 * 3.5. Neither the name Intel nor any other trademark owned or controlled by 77 * Intel shall be used in advertising or otherwise to promote the sale, use or 78 * other dealings in products derived from or relating to the Covered Code 79 * without prior written authorization from Intel. 80 * 81 * 4. Disclaimer and Export Compliance 82 * 83 * 4.1. INTEL MAKES NO WARRANTY OF ANY KIND REGARDING ANY SOFTWARE PROVIDED 84 * HERE. ANY SOFTWARE ORIGINATING FROM INTEL OR DERIVED FROM INTEL SOFTWARE 85 * IS PROVIDED "AS IS," AND INTEL WILL NOT PROVIDE ANY SUPPORT, ASSISTANCE, 86 * INSTALLATION, TRAINING OR OTHER SERVICES. INTEL WILL NOT PROVIDE ANY 87 * UPDATES, ENHANCEMENTS OR EXTENSIONS. INTEL SPECIFICALLY DISCLAIMS ANY 88 * IMPLIED WARRANTIES OF MERCHANTABILITY, NONINFRINGEMENT AND FITNESS FOR A 89 * PARTICULAR PURPOSE. 90 * 91 * 4.2. IN NO EVENT SHALL INTEL HAVE ANY LIABILITY TO LICENSEE, ITS LICENSEES 92 * OR ANY OTHER THIRD PARTY, FOR ANY LOST PROFITS, LOST DATA, LOSS OF USE OR 93 * COSTS OF PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES, OR FOR ANY INDIRECT, 94 * SPECIAL OR CONSEQUENTIAL DAMAGES ARISING OUT OF THIS AGREEMENT, UNDER ANY 95 * CAUSE OF ACTION OR THEORY OF LIABILITY, AND IRRESPECTIVE OF WHETHER INTEL 96 * HAS ADVANCE NOTICE OF THE POSSIBILITY OF SUCH DAMAGES. THESE LIMITATIONS 97 * SHALL APPLY NOTWITHSTANDING THE FAILURE OF THE ESSENTIAL PURPOSE OF ANY 98 * LIMITED REMEDY. 99 * 100 * 4.3. Licensee shall not export, either directly or indirectly, any of this 101 * software or system incorporating such software without first obtaining any 102 * required license or other approval from the U. S. Department of Commerce or 103 * any other agency or department of the United States Government. In the 104 * event Licensee exports any such software from the United States or 105 * re-exports any such software from a foreign destination, Licensee shall 106 * ensure that the distribution and export/re-export of the software is in 107 * compliance with all laws, regulations, orders, or other restrictions of the 108 * U.S. Export Administration Regulations. Licensee agrees that neither it nor 109 * any of its subsidiaries will export/re-export any technical data, process, 110 * software, or service, directly or indirectly, to any country for which the 111 * United States government or any agency thereof requires an export license, 112 * other governmental approval, or letter of assurance, without first obtaining 113 * such license, approval or letter. 114 * 115 *****************************************************************************/ 116 117 #include "acpi.h" 118 #include "accommon.h" 119 120 #define _COMPONENT ACPI_HARDWARE 121 ACPI_MODULE_NAME ("hwtimer") 122 123 124 /****************************************************************************** 125 * 126 * FUNCTION: AcpiGetTimerResolution 127 * 128 * PARAMETERS: Resolution - Where the resolution is returned 129 * 130 * RETURN: Status and timer resolution 131 * 132 * DESCRIPTION: Obtains resolution of the ACPI PM Timer (24 or 32 bits). 133 * 134 ******************************************************************************/ 135 136 ACPI_STATUS 137 AcpiGetTimerResolution ( 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 ((AcpiGbl_FADT.Flags & ACPI_FADT_32BIT_TIMER) == 0) 149 { 150 *Resolution = 24; 151 } 152 else 153 { 154 *Resolution = 32; 155 } 156 157 return_ACPI_STATUS (AE_OK); 158 } 159 160 ACPI_EXPORT_SYMBOL (AcpiGetTimerResolution) 161 162 163 /****************************************************************************** 164 * 165 * FUNCTION: AcpiGetTimer 166 * 167 * PARAMETERS: Ticks - Where the timer value is returned 168 * 169 * RETURN: Status and current timer value (ticks) 170 * 171 * DESCRIPTION: Obtains current value of ACPI PM Timer (in ticks). 172 * 173 ******************************************************************************/ 174 175 ACPI_STATUS 176 AcpiGetTimer ( 177 UINT32 *Ticks) 178 { 179 ACPI_STATUS Status; 180 181 182 ACPI_FUNCTION_TRACE (AcpiGetTimer); 183 184 185 if (!Ticks) 186 { 187 return_ACPI_STATUS (AE_BAD_PARAMETER); 188 } 189 190 Status = AcpiRead (Ticks, &AcpiGbl_FADT.XPmTimerBlock); 191 192 return_ACPI_STATUS (Status); 193 } 194 195 ACPI_EXPORT_SYMBOL (AcpiGetTimer) 196 197 198 /****************************************************************************** 199 * 200 * FUNCTION: AcpiGetTimerDuration 201 * 202 * PARAMETERS: StartTicks - Starting timestamp 203 * EndTicks - End timestamp 204 * TimeElapsed - Where the elapsed time is returned 205 * 206 * RETURN: Status and TimeElapsed 207 * 208 * DESCRIPTION: Computes the time elapsed (in microseconds) between two 209 * PM Timer time stamps, taking into account the possibility of 210 * rollovers, the timer resolution, and timer frequency. 211 * 212 * The PM Timer's clock ticks at roughly 3.6 times per 213 * _microsecond_, and its clock continues through Cx state 214 * transitions (unlike many CPU timestamp counters) -- making it 215 * a versatile and accurate timer. 216 * 217 * Note that this function accommodates only a single timer 218 * rollover. Thus for 24-bit timers, this function should only 219 * be used for calculating durations less than ~4.6 seconds 220 * (~20 minutes for 32-bit timers) -- calculations below: 221 * 222 * 2**24 Ticks / 3,600,000 Ticks/Sec = 4.66 sec 223 * 2**32 Ticks / 3,600,000 Ticks/Sec = 1193 sec or 19.88 minutes 224 * 225 ******************************************************************************/ 226 227 ACPI_STATUS 228 AcpiGetTimerDuration ( 229 UINT32 StartTicks, 230 UINT32 EndTicks, 231 UINT32 *TimeElapsed) 232 { 233 ACPI_STATUS Status; 234 UINT32 DeltaTicks; 235 ACPI_INTEGER Quotient; 236 237 238 ACPI_FUNCTION_TRACE (AcpiGetTimerDuration); 239 240 241 if (!TimeElapsed) 242 { 243 return_ACPI_STATUS (AE_BAD_PARAMETER); 244 } 245 246 /* 247 * Compute Tick Delta: 248 * Handle (max one) timer rollovers on 24-bit versus 32-bit timers. 249 */ 250 if (StartTicks < EndTicks) 251 { 252 DeltaTicks = EndTicks - StartTicks; 253 } 254 else if (StartTicks > EndTicks) 255 { 256 if ((AcpiGbl_FADT.Flags & ACPI_FADT_32BIT_TIMER) == 0) 257 { 258 /* 24-bit Timer */ 259 260 DeltaTicks = (((0x00FFFFFF - StartTicks) + EndTicks) & 0x00FFFFFF); 261 } 262 else 263 { 264 /* 32-bit Timer */ 265 266 DeltaTicks = (0xFFFFFFFF - StartTicks) + EndTicks; 267 } 268 } 269 else /* StartTicks == EndTicks */ 270 { 271 *TimeElapsed = 0; 272 return_ACPI_STATUS (AE_OK); 273 } 274 275 /* 276 * Compute Duration (Requires a 64-bit multiply and divide): 277 * 278 * TimeElapsed = (DeltaTicks * 1000000) / PM_TIMER_FREQUENCY; 279 */ 280 Status = AcpiUtShortDivide (((UINT64) DeltaTicks) * 1000000, 281 PM_TIMER_FREQUENCY, &Quotient, NULL); 282 283 *TimeElapsed = (UINT32) Quotient; 284 return_ACPI_STATUS (Status); 285 } 286 287 ACPI_EXPORT_SYMBOL (AcpiGetTimerDuration) 288 289