1 | /****************************************************************************** |
2 | * |
3 | * Name: hwtimer.c - ACPI Power Management Timer Interface |
4 | * |
5 | *****************************************************************************/ |
6 | |
7 | /* |
8 | * Copyright (C) 2000 - 2016, Intel Corp. |
9 | * All rights reserved. |
10 | * |
11 | * Redistribution and use in source and binary forms, with or without |
12 | * modification, are permitted provided that the following conditions |
13 | * are met: |
14 | * 1. Redistributions of source code must retain the above copyright |
15 | * notice, this list of conditions, and the following disclaimer, |
16 | * without modification. |
17 | * 2. Redistributions in binary form must reproduce at minimum a disclaimer |
18 | * substantially similar to the "NO WARRANTY" disclaimer below |
19 | * ("Disclaimer") and any redistribution must be conditioned upon |
20 | * including a substantially similar Disclaimer requirement for further |
21 | * binary redistribution. |
22 | * 3. Neither the names of the above-listed copyright holders nor the names |
23 | * of any contributors may be used to endorse or promote products derived |
24 | * from this software without specific prior written permission. |
25 | * |
26 | * Alternatively, this software may be distributed under the terms of the |
27 | * GNU General Public License ("GPL") version 2 as published by the Free |
28 | * Software Foundation. |
29 | * |
30 | * NO WARRANTY |
31 | * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS |
32 | * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT |
33 | * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTIBILITY AND FITNESS FOR |
34 | * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT |
35 | * HOLDERS OR CONTRIBUTORS BE LIABLE FOR SPECIAL, EXEMPLARY, OR CONSEQUENTIAL |
36 | * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS |
37 | * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) |
38 | * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, |
39 | * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING |
40 | * IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE |
41 | * POSSIBILITY OF SUCH DAMAGES. |
42 | */ |
43 | |
44 | #define EXPORT_ACPI_INTERFACES |
45 | |
46 | #include "acpi.h" |
47 | #include "accommon.h" |
48 | |
49 | #define _COMPONENT ACPI_HARDWARE |
50 | ACPI_MODULE_NAME ("hwtimer" ) |
51 | |
52 | |
53 | #if (!ACPI_REDUCED_HARDWARE) /* Entire module */ |
54 | /****************************************************************************** |
55 | * |
56 | * FUNCTION: AcpiGetTimerResolution |
57 | * |
58 | * PARAMETERS: Resolution - Where the resolution is returned |
59 | * |
60 | * RETURN: Status and timer resolution |
61 | * |
62 | * DESCRIPTION: Obtains resolution of the ACPI PM Timer (24 or 32 bits). |
63 | * |
64 | ******************************************************************************/ |
65 | |
66 | ACPI_STATUS |
67 | AcpiGetTimerResolution ( |
68 | UINT32 *Resolution) |
69 | { |
70 | ACPI_FUNCTION_TRACE (AcpiGetTimerResolution); |
71 | |
72 | |
73 | if (!Resolution) |
74 | { |
75 | return_ACPI_STATUS (AE_BAD_PARAMETER); |
76 | } |
77 | |
78 | if ((AcpiGbl_FADT.Flags & ACPI_FADT_32BIT_TIMER) == 0) |
79 | { |
80 | *Resolution = 24; |
81 | } |
82 | else |
83 | { |
84 | *Resolution = 32; |
85 | } |
86 | |
87 | return_ACPI_STATUS (AE_OK); |
88 | } |
89 | |
90 | ACPI_EXPORT_SYMBOL (AcpiGetTimerResolution) |
91 | |
92 | |
93 | /****************************************************************************** |
94 | * |
95 | * FUNCTION: AcpiGetTimer |
96 | * |
97 | * PARAMETERS: Ticks - Where the timer value is returned |
98 | * |
99 | * RETURN: Status and current timer value (ticks) |
100 | * |
101 | * DESCRIPTION: Obtains current value of ACPI PM Timer (in ticks). |
102 | * |
103 | ******************************************************************************/ |
104 | |
105 | ACPI_STATUS |
106 | AcpiGetTimer ( |
107 | UINT32 *Ticks) |
108 | { |
109 | ACPI_STATUS Status; |
110 | |
111 | |
112 | ACPI_FUNCTION_TRACE (AcpiGetTimer); |
113 | |
114 | |
115 | if (!Ticks) |
116 | { |
117 | return_ACPI_STATUS (AE_BAD_PARAMETER); |
118 | } |
119 | |
120 | /* ACPI 5.0A: PM Timer is optional */ |
121 | |
122 | if (!AcpiGbl_FADT.XPmTimerBlock.Address) |
123 | { |
124 | return_ACPI_STATUS (AE_SUPPORT); |
125 | } |
126 | |
127 | Status = AcpiHwRead (Ticks, &AcpiGbl_FADT.XPmTimerBlock); |
128 | return_ACPI_STATUS (Status); |
129 | } |
130 | |
131 | ACPI_EXPORT_SYMBOL (AcpiGetTimer) |
132 | |
133 | |
134 | /****************************************************************************** |
135 | * |
136 | * FUNCTION: AcpiGetTimerDuration |
137 | * |
138 | * PARAMETERS: StartTicks - Starting timestamp |
139 | * EndTicks - End timestamp |
140 | * TimeElapsed - Where the elapsed time is returned |
141 | * |
142 | * RETURN: Status and TimeElapsed |
143 | * |
144 | * DESCRIPTION: Computes the time elapsed (in microseconds) between two |
145 | * PM Timer time stamps, taking into account the possibility of |
146 | * rollovers, the timer resolution, and timer frequency. |
147 | * |
148 | * The PM Timer's clock ticks at roughly 3.6 times per |
149 | * _microsecond_, and its clock continues through Cx state |
150 | * transitions (unlike many CPU timestamp counters) -- making it |
151 | * a versatile and accurate timer. |
152 | * |
153 | * Note that this function accommodates only a single timer |
154 | * rollover. Thus for 24-bit timers, this function should only |
155 | * be used for calculating durations less than ~4.6 seconds |
156 | * (~20 minutes for 32-bit timers) -- calculations below: |
157 | * |
158 | * 2**24 Ticks / 3,600,000 Ticks/Sec = 4.66 sec |
159 | * 2**32 Ticks / 3,600,000 Ticks/Sec = 1193 sec or 19.88 minutes |
160 | * |
161 | ******************************************************************************/ |
162 | |
163 | ACPI_STATUS |
164 | AcpiGetTimerDuration ( |
165 | UINT32 StartTicks, |
166 | UINT32 EndTicks, |
167 | UINT32 *TimeElapsed) |
168 | { |
169 | ACPI_STATUS Status; |
170 | UINT32 DeltaTicks; |
171 | UINT64 Quotient; |
172 | |
173 | |
174 | ACPI_FUNCTION_TRACE (AcpiGetTimerDuration); |
175 | |
176 | |
177 | if (!TimeElapsed) |
178 | { |
179 | return_ACPI_STATUS (AE_BAD_PARAMETER); |
180 | } |
181 | |
182 | /* ACPI 5.0A: PM Timer is optional */ |
183 | |
184 | if (!AcpiGbl_FADT.XPmTimerBlock.Address) |
185 | { |
186 | return_ACPI_STATUS (AE_SUPPORT); |
187 | } |
188 | |
189 | /* |
190 | * Compute Tick Delta: |
191 | * Handle (max one) timer rollovers on 24-bit versus 32-bit timers. |
192 | */ |
193 | if (StartTicks < EndTicks) |
194 | { |
195 | DeltaTicks = EndTicks - StartTicks; |
196 | } |
197 | else if (StartTicks > EndTicks) |
198 | { |
199 | if ((AcpiGbl_FADT.Flags & ACPI_FADT_32BIT_TIMER) == 0) |
200 | { |
201 | /* 24-bit Timer */ |
202 | |
203 | DeltaTicks = (((0x00FFFFFF - StartTicks) + EndTicks) & 0x00FFFFFF); |
204 | } |
205 | else |
206 | { |
207 | /* 32-bit Timer */ |
208 | |
209 | DeltaTicks = (0xFFFFFFFF - StartTicks) + EndTicks; |
210 | } |
211 | } |
212 | else /* StartTicks == EndTicks */ |
213 | { |
214 | *TimeElapsed = 0; |
215 | return_ACPI_STATUS (AE_OK); |
216 | } |
217 | |
218 | /* |
219 | * Compute Duration (Requires a 64-bit multiply and divide): |
220 | * |
221 | * TimeElapsed (microseconds) = |
222 | * (DeltaTicks * ACPI_USEC_PER_SEC) / ACPI_PM_TIMER_FREQUENCY; |
223 | */ |
224 | Status = AcpiUtShortDivide (((UINT64) DeltaTicks) * ACPI_USEC_PER_SEC, |
225 | ACPI_PM_TIMER_FREQUENCY, &Quotient, NULL); |
226 | |
227 | *TimeElapsed = (UINT32) Quotient; |
228 | return_ACPI_STATUS (Status); |
229 | } |
230 | |
231 | ACPI_EXPORT_SYMBOL (AcpiGetTimerDuration) |
232 | |
233 | #endif /* !ACPI_REDUCED_HARDWARE */ |
234 | |