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Diffstat (limited to 'sys/contrib/dev/acpica/hwtimer.c')
| -rw-r--r-- | sys/contrib/dev/acpica/hwtimer.c | 302 |
1 files changed, 302 insertions, 0 deletions
diff --git a/sys/contrib/dev/acpica/hwtimer.c b/sys/contrib/dev/acpica/hwtimer.c new file mode 100644 index 0000000..197c65c --- /dev/null +++ b/sys/contrib/dev/acpica/hwtimer.c @@ -0,0 +1,302 @@ + +/****************************************************************************** + * + * Name: hwtimer.c - ACPI Power Management Timer Interface + * $Revision: 4 $ + * + *****************************************************************************/ + +/****************************************************************************** + * + * 1. Copyright Notice + * + * Some or all of this work - Copyright (c) 1999, 2000, 2001, Intel Corp. + * All rights reserved. + * + * 2. License + * + * 2.1. This is your license from Intel Corp. under its intellectual property + * rights. You may have additional license terms from the party that provided + * you this software, covering your right to use that party's intellectual + * property rights. + * + * 2.2. Intel grants, free of charge, to any person ("Licensee") obtaining a + * copy of the source code appearing in this file ("Covered Code") an + * irrevocable, perpetual, worldwide license under Intel's copyrights in the + * base code distributed originally by Intel ("Original Intel Code") to copy, + * make derivatives, distribute, use and display any portion of the Covered + * Code in any form, with the right to sublicense such rights; and + * + * 2.3. Intel grants Licensee a non-exclusive and non-transferable patent + * license (with the right to sublicense), under only those claims of Intel + * patents that are infringed by the Original Intel Code, to make, use, sell, + * offer to sell, and import the Covered Code and derivative works thereof + * solely to the minimum extent necessary to exercise the above copyright + * license, and in no event shall the patent license extend to any additions + * to or modifications of the Original Intel Code. No other license or right + * is granted directly or by implication, estoppel or otherwise; + * + * The above copyright and patent license is granted only if the following + * conditions are met: + * + * 3. Conditions + * + * 3.1. Redistribution of Source with Rights to Further Distribute Source. + * Redistribution of source code of any substantial portion of the Covered + * Code or modification with rights to further distribute source must include + * the above Copyright Notice, the above License, this list of Conditions, + * and the following Disclaimer and Export Compliance provision. In addition, + * Licensee must cause all Covered Code to which Licensee contributes to + * contain a file documenting the changes Licensee made to create that Covered + * Code and the date of any change. Licensee must include in that file the + * documentation of any changes made by any predecessor Licensee. Licensee + * must include a prominent statement that the modification is derived, + * directly or indirectly, from Original Intel Code. + * + * 3.2. Redistribution of Source with no Rights to Further Distribute Source. + * Redistribution of source code of any substantial portion of the Covered + * Code or modification without rights to further distribute source must + * include the following Disclaimer and Export Compliance provision in the + * documentation and/or other materials provided with distribution. In + * addition, Licensee may not authorize further sublicense of source of any + * portion of the Covered Code, and must include terms to the effect that the + * license from Licensee to its licensee is limited to the intellectual + * property embodied in the software Licensee provides to its licensee, and + * not to intellectual property embodied in modifications its licensee may + * make. + * + * 3.3. Redistribution of Executable. Redistribution in executable form of any + * substantial portion of the Covered Code or modification must reproduce the + * above Copyright Notice, and the following Disclaimer and Export Compliance + * provision in the documentation and/or other materials provided with the + * distribution. + * + * 3.4. Intel retains all right, title, and interest in and to the Original + * Intel Code. + * + * 3.5. Neither the name Intel nor any other trademark owned or controlled by + * Intel shall be used in advertising or otherwise to promote the sale, use or + * other dealings in products derived from or relating to the Covered Code + * without prior written authorization from Intel. + * + * 4. Disclaimer and Export Compliance + * + * 4.1. INTEL MAKES NO WARRANTY OF ANY KIND REGARDING ANY SOFTWARE PROVIDED + * HERE. ANY SOFTWARE ORIGINATING FROM INTEL OR DERIVED FROM INTEL SOFTWARE + * IS PROVIDED "AS IS," AND INTEL WILL NOT PROVIDE ANY SUPPORT, ASSISTANCE, + * INSTALLATION, TRAINING OR OTHER SERVICES. INTEL WILL NOT PROVIDE ANY + * UPDATES, ENHANCEMENTS OR EXTENSIONS. INTEL SPECIFICALLY DISCLAIMS ANY + * IMPLIED WARRANTIES OF MERCHANTABILITY, NONINFRINGEMENT AND FITNESS FOR A + * PARTICULAR PURPOSE. + * + * 4.2. IN NO EVENT SHALL INTEL HAVE ANY LIABILITY TO LICENSEE, ITS LICENSEES + * OR ANY OTHER THIRD PARTY, FOR ANY LOST PROFITS, LOST DATA, LOSS OF USE OR + * COSTS OF PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES, OR FOR ANY INDIRECT, + * SPECIAL OR CONSEQUENTIAL DAMAGES ARISING OUT OF THIS AGREEMENT, UNDER ANY + * CAUSE OF ACTION OR THEORY OF LIABILITY, AND IRRESPECTIVE OF WHETHER INTEL + * HAS ADVANCE NOTICE OF THE POSSIBILITY OF SUCH DAMAGES. THESE LIMITATIONS + * SHALL APPLY NOTWITHSTANDING THE FAILURE OF THE ESSENTIAL PURPOSE OF ANY + * LIMITED REMEDY. + * + * 4.3. Licensee shall not export, either directly or indirectly, any of this + * software or system incorporating such software without first obtaining any + * required license or other approval from the U. S. Department of Commerce or + * any other agency or department of the United States Government. In the + * event Licensee exports any such software from the United States or + * re-exports any such software from a foreign destination, Licensee shall + * ensure that the distribution and export/re-export of the software is in + * compliance with all laws, regulations, orders, or other restrictions of the + * U.S. Export Administration Regulations. Licensee agrees that neither it nor + * any of its subsidiaries will export/re-export any technical data, process, + * software, or service, directly or indirectly, to any country for which the + * United States government or any agency thereof requires an export license, + * other governmental approval, or letter of assurance, without first obtaining + * such license, approval or letter. + * + *****************************************************************************/ + +#include "acpi.h" +#include "achware.h" + +#define _COMPONENT HARDWARE + MODULE_NAME ("hwtimer") + + +/****************************************************************************** + * + * FUNCTION: AcpiGetTimerResolution + * + * PARAMETERS: none + * + * RETURN: Number of bits of resolution in the PM Timer (24 or 32). + * + * DESCRIPTION: Obtains resolution of the ACPI PM Timer. + * + ******************************************************************************/ + +ACPI_STATUS +AcpiGetTimerResolution ( + UINT32 *Resolution) +{ + FUNCTION_TRACE ("AcpiGetTimerResolution"); + + if (!Resolution) + { + return_ACPI_STATUS (AE_BAD_PARAMETER); + } + + if (0 == AcpiGbl_FADT->TmrValExt) + { + *Resolution = 24; + } + else + { + *Resolution = 32; + } + + return_ACPI_STATUS (AE_OK); +} + + +/****************************************************************************** + * + * FUNCTION: AcpiGetTimer + * + * PARAMETERS: none + * + * RETURN: Current value of the ACPI PM Timer (in ticks). + * + * DESCRIPTION: Obtains current value of ACPI PM Timer. + * + ******************************************************************************/ + +ACPI_STATUS +AcpiGetTimer ( + UINT32 *Ticks) +{ + FUNCTION_TRACE ("AcpiGetTimer"); + + if (!Ticks) + { + return_ACPI_STATUS (AE_BAD_PARAMETER); + } + + *Ticks = AcpiOsIn32 ((ACPI_IO_ADDRESS) ACPI_GET_ADDRESS (AcpiGbl_FADT->XPmTmrBlk.Address)); + + return_ACPI_STATUS (AE_OK); +} + + +/****************************************************************************** + * + * FUNCTION: AcpiGetTimerDuration + * + * PARAMETERS: StartTicks + * EndTicks + * TimeElapsed + * + * RETURN: TimeElapsed + * + * DESCRIPTION: Computes the time elapsed (in microseconds) between two + * PM Timer time stamps, taking into account the possibility of + * rollovers, the timer resolution, and timer frequency. + * + * The PM Timer's clock ticks at roughly 3.6 times per + * _microsecond_, and its clock continues through Cx state + * transitions (unlike many CPU timestamp counters) -- making it + * a versatile and accurate timer. + * + * Note that this function accomodates only a single timer + * rollover. Thus for 24-bit timers, this function should only + * be used for calculating durations less than ~4.6 seconds + * (~20 hours for 32-bit timers). + * + ******************************************************************************/ + +ACPI_STATUS +AcpiGetTimerDuration ( + UINT32 StartTicks, + UINT32 EndTicks, + UINT32 *TimeElapsed) +{ + UINT32 DeltaTicks = 0; + UINT32 Seconds = 0; + UINT32 Milliseconds = 0; + UINT32 Microseconds = 0; + UINT32 Remainder = 0; + + FUNCTION_TRACE ("AcpiGetTimerDuration"); + + if (!TimeElapsed) + { + return_ACPI_STATUS (AE_BAD_PARAMETER); + } + + /* + * Compute Tick Delta: + * ------------------- + * Handle timer rollovers on 24- versus 32-bit timers. + */ + if (StartTicks < EndTicks) + { + DeltaTicks = EndTicks - StartTicks; + } + else if (StartTicks > EndTicks) + { + /* 24-bit Timer */ + if (0 == AcpiGbl_FADT->TmrValExt) + { + DeltaTicks = (0x00FFFFFF - StartTicks) + EndTicks; + } + /* 32-bit Timer */ + else + { + DeltaTicks = (0xFFFFFFFF - StartTicks) + EndTicks; + } + } + + /* + * Compute Duration: + * ----------------- + * Since certain compilers (gcc/Linux, argh!) don't support 64-bit + * divides in kernel-space we have to do some trickery to preserve + * accuracy while using 32-bit math. + * + * TODO: Change to use 64-bit math when supported. + * + * The process is as follows: + * 1. Compute the number of seconds by dividing Delta Ticks by + * the timer frequency. + * 2. Compute the number of milliseconds in the remainder from step #1 + * by multiplying by 1000 and then dividing by the timer frequency. + * 3. Compute the number of microseconds in the remainder from step #2 + * by multiplying by 1000 and then dividing by the timer frequency. + * 4. Add the results from steps 1, 2, and 3 to get the total duration. + * + * Example: The time elapsed for DeltaTicks = 0xFFFFFFFF should be + * 1199864031 microseconds. This is computed as follows: + * Step #1: Seconds = 1199; Remainder = 3092840 + * Step #2: Milliseconds = 864; Remainder = 113120 + * Step #3: Microseconds = 31; Remainder = <don't care!> + */ + + /* Step #1 */ + Seconds = DeltaTicks / PM_TIMER_FREQUENCY; + Remainder = DeltaTicks % PM_TIMER_FREQUENCY; + + /* Step #2 */ + Milliseconds = (Remainder * 1000) / PM_TIMER_FREQUENCY; + Remainder = (Remainder * 1000) % PM_TIMER_FREQUENCY; + + /* Step #3 */ + Microseconds = (Remainder * 1000) / PM_TIMER_FREQUENCY; + + /* Step #4 */ + *TimeElapsed = Seconds * 1000000; + *TimeElapsed += Milliseconds * 1000; + *TimeElapsed += Microseconds; + + return_ACPI_STATUS (AE_OK); +} + + |
