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 - 2013, 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 #include "acpi.h" 117 #include "accommon.h" 118 119 #define _COMPONENT ACPI_HARDWARE 120 ACPI_MODULE_NAME ("hwtimer") 121 122 123 #if (!ACPI_REDUCED_HARDWARE) /* Entire module */ 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 /* ACPI 5.0A: PM Timer is optional */ 191 192 if (!AcpiGbl_FADT.XPmTimerBlock.Address) 193 { 194 return_ACPI_STATUS (AE_SUPPORT); 195 } 196 197 Status = AcpiHwRead (Ticks, &AcpiGbl_FADT.XPmTimerBlock); 198 return_ACPI_STATUS (Status); 199 } 200 201 ACPI_EXPORT_SYMBOL (AcpiGetTimer) 202 203 204 /****************************************************************************** 205 * 206 * FUNCTION: AcpiGetTimerDuration 207 * 208 * PARAMETERS: StartTicks - Starting timestamp 209 * EndTicks - End timestamp 210 * TimeElapsed - Where the elapsed time is returned 211 * 212 * RETURN: Status and TimeElapsed 213 * 214 * DESCRIPTION: Computes the time elapsed (in microseconds) between two 215 * PM Timer time stamps, taking into account the possibility of 216 * rollovers, the timer resolution, and timer frequency. 217 * 218 * The PM Timer's clock ticks at roughly 3.6 times per 219 * _microsecond_, and its clock continues through Cx state 220 * transitions (unlike many CPU timestamp counters) -- making it 221 * a versatile and accurate timer. 222 * 223 * Note that this function accommodates only a single timer 224 * rollover. Thus for 24-bit timers, this function should only 225 * be used for calculating durations less than ~4.6 seconds 226 * (~20 minutes for 32-bit timers) -- calculations below: 227 * 228 * 2**24 Ticks / 3,600,000 Ticks/Sec = 4.66 sec 229 * 2**32 Ticks / 3,600,000 Ticks/Sec = 1193 sec or 19.88 minutes 230 * 231 ******************************************************************************/ 232 233 ACPI_STATUS 234 AcpiGetTimerDuration ( 235 UINT32 StartTicks, 236 UINT32 EndTicks, 237 UINT32 *TimeElapsed) 238 { 239 ACPI_STATUS Status; 240 UINT32 DeltaTicks; 241 UINT64 Quotient; 242 243 244 ACPI_FUNCTION_TRACE (AcpiGetTimerDuration); 245 246 247 if (!TimeElapsed) 248 { 249 return_ACPI_STATUS (AE_BAD_PARAMETER); 250 } 251 252 /* ACPI 5.0A: PM Timer is optional */ 253 254 if (!AcpiGbl_FADT.XPmTimerBlock.Address) 255 { 256 return_ACPI_STATUS (AE_SUPPORT); 257 } 258 259 /* 260 * Compute Tick Delta: 261 * Handle (max one) timer rollovers on 24-bit versus 32-bit timers. 262 */ 263 if (StartTicks < EndTicks) 264 { 265 DeltaTicks = EndTicks - StartTicks; 266 } 267 else if (StartTicks > EndTicks) 268 { 269 if ((AcpiGbl_FADT.Flags & ACPI_FADT_32BIT_TIMER) == 0) 270 { 271 /* 24-bit Timer */ 272 273 DeltaTicks = (((0x00FFFFFF - StartTicks) + EndTicks) & 0x00FFFFFF); 274 } 275 else 276 { 277 /* 32-bit Timer */ 278 279 DeltaTicks = (0xFFFFFFFF - StartTicks) + EndTicks; 280 } 281 } 282 else /* StartTicks == EndTicks */ 283 { 284 *TimeElapsed = 0; 285 return_ACPI_STATUS (AE_OK); 286 } 287 288 /* 289 * Compute Duration (Requires a 64-bit multiply and divide): 290 * 291 * TimeElapsed (microseconds) = 292 * (DeltaTicks * ACPI_USEC_PER_SEC) / ACPI_PM_TIMER_FREQUENCY; 293 */ 294 Status = AcpiUtShortDivide (((UINT64) DeltaTicks) * ACPI_USEC_PER_SEC, 295 ACPI_PM_TIMER_FREQUENCY, &Quotient, NULL); 296 297 *TimeElapsed = (UINT32) Quotient; 298 return_ACPI_STATUS (Status); 299 } 300 301 ACPI_EXPORT_SYMBOL (AcpiGetTimerDuration) 302 303 #endif /* !ACPI_REDUCED_HARDWARE */ 304