1 /******************************************************************************
3 * Name: hwtimer.c - ACPI Power Management Timer Interface
5 *****************************************************************************/
7 /******************************************************************************
11 * Some or all of this work - Copyright (c) 1999 - 2018, Intel Corp.
12 * All rights reserved.
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
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
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;
37 * The above copyright and patent license is granted only if the following
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.
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
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
72 * 3.4. Intel retains all right, title, and interest in and to the Original
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.
80 * 4. Disclaimer and Export Compliance
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
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
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.
114 *****************************************************************************
116 * Alternatively, you may choose to be licensed under the terms of the
119 * Redistribution and use in source and binary forms, with or without
120 * modification, are permitted provided that the following conditions
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.
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.
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.
150 *****************************************************************************/
152 #define EXPORT_ACPI_INTERFACES
155 #include "accommon.h"
157 #define _COMPONENT ACPI_HARDWARE
158 ACPI_MODULE_NAME ("hwtimer")
161 #if (!ACPI_REDUCED_HARDWARE) /* Entire module */
162 /******************************************************************************
164 * FUNCTION: AcpiGetTimerResolution
166 * PARAMETERS: Resolution - Where the resolution is returned
168 * RETURN: Status and timer resolution
170 * DESCRIPTION: Obtains resolution of the ACPI PM Timer (24 or 32 bits).
172 ******************************************************************************/
175 AcpiGetTimerResolution (
178 ACPI_FUNCTION_TRACE (AcpiGetTimerResolution
);
183 return_ACPI_STATUS (AE_BAD_PARAMETER
);
186 if ((AcpiGbl_FADT
.Flags
& ACPI_FADT_32BIT_TIMER
) == 0)
195 return_ACPI_STATUS (AE_OK
);
198 ACPI_EXPORT_SYMBOL (AcpiGetTimerResolution
)
201 /******************************************************************************
203 * FUNCTION: AcpiGetTimer
205 * PARAMETERS: Ticks - Where the timer value is returned
207 * RETURN: Status and current timer value (ticks)
209 * DESCRIPTION: Obtains current value of ACPI PM Timer (in ticks).
211 ******************************************************************************/
221 ACPI_FUNCTION_TRACE (AcpiGetTimer
);
226 return_ACPI_STATUS (AE_BAD_PARAMETER
);
229 /* ACPI 5.0A: PM Timer is optional */
231 if (!AcpiGbl_FADT
.XPmTimerBlock
.Address
)
233 return_ACPI_STATUS (AE_SUPPORT
);
236 Status
= AcpiHwRead (&TimerValue
, &AcpiGbl_FADT
.XPmTimerBlock
);
237 if (ACPI_SUCCESS (Status
))
239 /* ACPI PM Timer is defined to be 32 bits (PM_TMR_LEN) */
241 *Ticks
= (UINT32
) TimerValue
;
244 return_ACPI_STATUS (Status
);
247 ACPI_EXPORT_SYMBOL (AcpiGetTimer
)
250 /******************************************************************************
252 * FUNCTION: AcpiGetTimerDuration
254 * PARAMETERS: StartTicks - Starting timestamp
255 * EndTicks - End timestamp
256 * TimeElapsed - Where the elapsed time is returned
258 * RETURN: Status and TimeElapsed
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.
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.
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:
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
277 ******************************************************************************/
280 AcpiGetTimerDuration (
290 ACPI_FUNCTION_TRACE (AcpiGetTimerDuration
);
295 return_ACPI_STATUS (AE_BAD_PARAMETER
);
298 /* ACPI 5.0A: PM Timer is optional */
300 if (!AcpiGbl_FADT
.XPmTimerBlock
.Address
)
302 return_ACPI_STATUS (AE_SUPPORT
);
305 if (StartTicks
== EndTicks
)
308 return_ACPI_STATUS (AE_OK
);
312 * Compute Tick Delta:
313 * Handle (max one) timer rollovers on 24-bit versus 32-bit timers.
315 DeltaTicks
= EndTicks
;
316 if (StartTicks
> EndTicks
)
318 if ((AcpiGbl_FADT
.Flags
& ACPI_FADT_32BIT_TIMER
) == 0)
322 DeltaTicks
|= (UINT64
) 1 << 24;
328 DeltaTicks
|= (UINT64
) 1 << 32;
331 DeltaTicks
-= StartTicks
;
334 * Compute Duration (Requires a 64-bit multiply and divide):
336 * TimeElapsed (microseconds) =
337 * (DeltaTicks * ACPI_USEC_PER_SEC) / ACPI_PM_TIMER_FREQUENCY;
339 Status
= AcpiUtShortDivide (DeltaTicks
* ACPI_USEC_PER_SEC
,
340 ACPI_PM_TIMER_FREQUENCY
, &Quotient
, NULL
);
342 *TimeElapsed
= (UINT32
) Quotient
;
343 return_ACPI_STATUS (Status
);
346 ACPI_EXPORT_SYMBOL (AcpiGetTimerDuration
)
348 #endif /* !ACPI_REDUCED_HARDWARE */