1 /****************************************************************************** 2 * 3 * Name: hwtimer.c - ACPI Power Management Timer Interface 4 * 5 *****************************************************************************/ 6 7 /****************************************************************************** 8 * 9 * 1. Copyright Notice 10 * 11 * Some or all of this work - Copyright (c) 1999 - 2018, Intel Corp. 12 * All rights reserved. 13 * 14 * 2. License 15 * 16 * 2.1. This is your license from Intel Corp. under its intellectual property 17 * rights. You may have additional license terms from the party that provided 18 * you this software, covering your right to use that party's intellectual 19 * property rights. 20 * 21 * 2.2. Intel grants, free of charge, to any person ("Licensee") obtaining a 22 * copy of the source code appearing in this file ("Covered Code") an 23 * irrevocable, perpetual, worldwide license under Intel's copyrights in the 24 * base code distributed originally by Intel ("Original Intel Code") to copy, 25 * make derivatives, distribute, use and display any portion of the Covered 26 * Code in any form, with the right to sublicense such rights; and 27 * 28 * 2.3. Intel grants Licensee a non-exclusive and non-transferable patent 29 * license (with the right to sublicense), under only those claims of Intel 30 * patents that are infringed by the Original Intel Code, to make, use, sell, 31 * offer to sell, and import the Covered Code and derivative works thereof 32 * solely to the minimum extent necessary to exercise the above copyright 33 * license, and in no event shall the patent license extend to any additions 34 * to or modifications of the Original Intel Code. No other license or right 35 * is granted directly or by implication, estoppel or otherwise; 36 * 37 * The above copyright and patent license is granted only if the following 38 * conditions are met: 39 * 40 * 3. Conditions 41 * 42 * 3.1. Redistribution of Source with Rights to Further Distribute Source. 43 * Redistribution of source code of any substantial portion of the Covered 44 * Code or modification with rights to further distribute source must include 45 * the above Copyright Notice, the above License, this list of Conditions, 46 * and the following Disclaimer and Export Compliance provision. In addition, 47 * Licensee must cause all Covered Code to which Licensee contributes to 48 * contain a file documenting the changes Licensee made to create that Covered 49 * Code and the date of any change. Licensee must include in that file the 50 * documentation of any changes made by any predecessor Licensee. Licensee 51 * must include a prominent statement that the modification is derived, 52 * directly or indirectly, from Original Intel Code. 53 * 54 * 3.2. Redistribution of Source with no Rights to Further Distribute Source. 55 * Redistribution of source code of any substantial portion of the Covered 56 * Code or modification without rights to further distribute source must 57 * include the following Disclaimer and Export Compliance provision in the 58 * documentation and/or other materials provided with distribution. In 59 * addition, Licensee may not authorize further sublicense of source of any 60 * portion of the Covered Code, and must include terms to the effect that the 61 * license from Licensee to its licensee is limited to the intellectual 62 * property embodied in the software Licensee provides to its licensee, and 63 * not to intellectual property embodied in modifications its licensee may 64 * make. 65 * 66 * 3.3. Redistribution of Executable. Redistribution in executable form of any 67 * substantial portion of the Covered Code or modification must reproduce the 68 * above Copyright Notice, and the following Disclaimer and Export Compliance 69 * provision in the documentation and/or other materials provided with the 70 * distribution. 71 * 72 * 3.4. Intel retains all right, title, and interest in and to the Original 73 * Intel Code. 74 * 75 * 3.5. Neither the name Intel nor any other trademark owned or controlled by 76 * Intel shall be used in advertising or otherwise to promote the sale, use or 77 * other dealings in products derived from or relating to the Covered Code 78 * without prior written authorization from Intel. 79 * 80 * 4. Disclaimer and Export Compliance 81 * 82 * 4.1. INTEL MAKES NO WARRANTY OF ANY KIND REGARDING ANY SOFTWARE PROVIDED 83 * HERE. ANY SOFTWARE ORIGINATING FROM INTEL OR DERIVED FROM INTEL SOFTWARE 84 * IS PROVIDED "AS IS," AND INTEL WILL NOT PROVIDE ANY SUPPORT, ASSISTANCE, 85 * INSTALLATION, TRAINING OR OTHER SERVICES. INTEL WILL NOT PROVIDE ANY 86 * UPDATES, ENHANCEMENTS OR EXTENSIONS. INTEL SPECIFICALLY DISCLAIMS ANY 87 * IMPLIED WARRANTIES OF MERCHANTABILITY, NONINFRINGEMENT AND FITNESS FOR A 88 * PARTICULAR PURPOSE. 89 * 90 * 4.2. IN NO EVENT SHALL INTEL HAVE ANY LIABILITY TO LICENSEE, ITS LICENSEES 91 * OR ANY OTHER THIRD PARTY, FOR ANY LOST PROFITS, LOST DATA, LOSS OF USE OR 92 * COSTS OF PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES, OR FOR ANY INDIRECT, 93 * SPECIAL OR CONSEQUENTIAL DAMAGES ARISING OUT OF THIS AGREEMENT, UNDER ANY 94 * CAUSE OF ACTION OR THEORY OF LIABILITY, AND IRRESPECTIVE OF WHETHER INTEL 95 * HAS ADVANCE NOTICE OF THE POSSIBILITY OF SUCH DAMAGES. THESE LIMITATIONS 96 * SHALL APPLY NOTWITHSTANDING THE FAILURE OF THE ESSENTIAL PURPOSE OF ANY 97 * LIMITED REMEDY. 98 * 99 * 4.3. Licensee shall not export, either directly or indirectly, any of this 100 * software or system incorporating such software without first obtaining any 101 * required license or other approval from the U. S. Department of Commerce or 102 * any other agency or department of the United States Government. In the 103 * event Licensee exports any such software from the United States or 104 * re-exports any such software from a foreign destination, Licensee shall 105 * ensure that the distribution and export/re-export of the software is in 106 * compliance with all laws, regulations, orders, or other restrictions of the 107 * U.S. Export Administration Regulations. Licensee agrees that neither it nor 108 * any of its subsidiaries will export/re-export any technical data, process, 109 * software, or service, directly or indirectly, to any country for which the 110 * United States government or any agency thereof requires an export license, 111 * other governmental approval, or letter of assurance, without first obtaining 112 * such license, approval or letter. 113 * 114 ***************************************************************************** 115 * 116 * Alternatively, you may choose to be licensed under the terms of the 117 * following license: 118 * 119 * Redistribution and use in source and binary forms, with or without 120 * modification, are permitted provided that the following conditions 121 * are met: 122 * 1. Redistributions of source code must retain the above copyright 123 * notice, this list of conditions, and the following disclaimer, 124 * without modification. 125 * 2. Redistributions in binary form must reproduce at minimum a disclaimer 126 * substantially similar to the "NO WARRANTY" disclaimer below 127 * ("Disclaimer") and any redistribution must be conditioned upon 128 * including a substantially similar Disclaimer requirement for further 129 * binary redistribution. 130 * 3. Neither the names of the above-listed copyright holders nor the names 131 * of any contributors may be used to endorse or promote products derived 132 * from this software without specific prior written permission. 133 * 134 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS 135 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT 136 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR 137 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT 138 * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, 139 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT 140 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 141 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 142 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 143 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE 144 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 145 * 146 * Alternatively, you may choose to be licensed under the terms of the 147 * GNU General Public License ("GPL") version 2 as published by the Free 148 * Software Foundation. 149 * 150 *****************************************************************************/ 151 152 #define EXPORT_ACPI_INTERFACES 153 154 #include "acpi.h" 155 #include "accommon.h" 156 157 #define _COMPONENT ACPI_HARDWARE 158 ACPI_MODULE_NAME ("hwtimer") 159 160 161 #if (!ACPI_REDUCED_HARDWARE) /* Entire module */ 162 /****************************************************************************** 163 * 164 * FUNCTION: AcpiGetTimerResolution 165 * 166 * PARAMETERS: Resolution - Where the resolution is returned 167 * 168 * RETURN: Status and timer resolution 169 * 170 * DESCRIPTION: Obtains resolution of the ACPI PM Timer (24 or 32 bits). 171 * 172 ******************************************************************************/ 173 174 ACPI_STATUS 175 AcpiGetTimerResolution ( 176 UINT32 *Resolution) 177 { 178 ACPI_FUNCTION_TRACE (AcpiGetTimerResolution); 179 180 181 if (!Resolution) 182 { 183 return_ACPI_STATUS (AE_BAD_PARAMETER); 184 } 185 186 if ((AcpiGbl_FADT.Flags & ACPI_FADT_32BIT_TIMER) == 0) 187 { 188 *Resolution = 24; 189 } 190 else 191 { 192 *Resolution = 32; 193 } 194 195 return_ACPI_STATUS (AE_OK); 196 } 197 198 ACPI_EXPORT_SYMBOL (AcpiGetTimerResolution) 199 200 201 /****************************************************************************** 202 * 203 * FUNCTION: AcpiGetTimer 204 * 205 * PARAMETERS: Ticks - Where the timer value is returned 206 * 207 * RETURN: Status and current timer value (ticks) 208 * 209 * DESCRIPTION: Obtains current value of ACPI PM Timer (in ticks). 210 * 211 ******************************************************************************/ 212 213 ACPI_STATUS 214 AcpiGetTimer ( 215 UINT32 *Ticks) 216 { 217 ACPI_STATUS Status; 218 UINT64 TimerValue; 219 220 221 ACPI_FUNCTION_TRACE (AcpiGetTimer); 222 223 224 if (!Ticks) 225 { 226 return_ACPI_STATUS (AE_BAD_PARAMETER); 227 } 228 229 /* ACPI 5.0A: PM Timer is optional */ 230 231 if (!AcpiGbl_FADT.XPmTimerBlock.Address) 232 { 233 return_ACPI_STATUS (AE_SUPPORT); 234 } 235 236 Status = AcpiHwRead (&TimerValue, &AcpiGbl_FADT.XPmTimerBlock); 237 if (ACPI_SUCCESS (Status)) 238 { 239 /* ACPI PM Timer is defined to be 32 bits (PM_TMR_LEN) */ 240 241 *Ticks = (UINT32) TimerValue; 242 } 243 244 return_ACPI_STATUS (Status); 245 } 246 247 ACPI_EXPORT_SYMBOL (AcpiGetTimer) 248 249 250 /****************************************************************************** 251 * 252 * FUNCTION: AcpiGetTimerDuration 253 * 254 * PARAMETERS: StartTicks - Starting timestamp 255 * EndTicks - End timestamp 256 * TimeElapsed - Where the elapsed time is returned 257 * 258 * RETURN: Status and TimeElapsed 259 * 260 * DESCRIPTION: Computes the time elapsed (in microseconds) between two 261 * PM Timer time stamps, taking into account the possibility of 262 * rollovers, the timer resolution, and timer frequency. 263 * 264 * The PM Timer's clock ticks at roughly 3.6 times per 265 * _microsecond_, and its clock continues through Cx state 266 * transitions (unlike many CPU timestamp counters) -- making it 267 * a versatile and accurate timer. 268 * 269 * Note that this function accommodates only a single timer 270 * rollover. Thus for 24-bit timers, this function should only 271 * be used for calculating durations less than ~4.6 seconds 272 * (~20 minutes for 32-bit timers) -- calculations below: 273 * 274 * 2**24 Ticks / 3,600,000 Ticks/Sec = 4.66 sec 275 * 2**32 Ticks / 3,600,000 Ticks/Sec = 1193 sec or 19.88 minutes 276 * 277 ******************************************************************************/ 278 279 ACPI_STATUS 280 AcpiGetTimerDuration ( 281 UINT32 StartTicks, 282 UINT32 EndTicks, 283 UINT32 *TimeElapsed) 284 { 285 ACPI_STATUS Status; 286 UINT64 DeltaTicks; 287 UINT64 Quotient; 288 289 290 ACPI_FUNCTION_TRACE (AcpiGetTimerDuration); 291 292 293 if (!TimeElapsed) 294 { 295 return_ACPI_STATUS (AE_BAD_PARAMETER); 296 } 297 298 /* ACPI 5.0A: PM Timer is optional */ 299 300 if (!AcpiGbl_FADT.XPmTimerBlock.Address) 301 { 302 return_ACPI_STATUS (AE_SUPPORT); 303 } 304 305 if (StartTicks == EndTicks) 306 { 307 *TimeElapsed = 0; 308 return_ACPI_STATUS (AE_OK); 309 } 310 311 /* 312 * Compute Tick Delta: 313 * Handle (max one) timer rollovers on 24-bit versus 32-bit timers. 314 */ 315 DeltaTicks = EndTicks; 316 if (StartTicks > EndTicks) 317 { 318 if ((AcpiGbl_FADT.Flags & ACPI_FADT_32BIT_TIMER) == 0) 319 { 320 /* 24-bit Timer */ 321 322 DeltaTicks |= (UINT64) 1 << 24; 323 } 324 else 325 { 326 /* 32-bit Timer */ 327 328 DeltaTicks |= (UINT64) 1 << 32; 329 } 330 } 331 DeltaTicks -= StartTicks; 332 333 /* 334 * Compute Duration (Requires a 64-bit multiply and divide): 335 * 336 * TimeElapsed (microseconds) = 337 * (DeltaTicks * ACPI_USEC_PER_SEC) / ACPI_PM_TIMER_FREQUENCY; 338 */ 339 Status = AcpiUtShortDivide (DeltaTicks * ACPI_USEC_PER_SEC, 340 ACPI_PM_TIMER_FREQUENCY, &Quotient, NULL); 341 342 *TimeElapsed = (UINT32) Quotient; 343 return_ACPI_STATUS (Status); 344 } 345 346 ACPI_EXPORT_SYMBOL (AcpiGetTimerDuration) 347 348 #endif /* !ACPI_REDUCED_HARDWARE */ 349