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 - 2023, 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
174ACPI_STATUS
175AcpiGetTimerResolution (
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
198ACPI_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
213ACPI_STATUS
214AcpiGetTimer (
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
247ACPI_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
279ACPI_STATUS
280AcpiGetTimerDuration (
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
346ACPI_EXPORT_SYMBOL (AcpiGetTimerDuration)
347
348#endif /* !ACPI_REDUCED_HARDWARE */
349