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 - 2020, 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