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1da177e4 LT |
1 | /****************************************************************************** |
2 | * | |
3 | * Name: hwtimer.c - ACPI Power Management Timer Interface | |
4 | * | |
5 | *****************************************************************************/ | |
6 | ||
7 | /* | |
82a80941 | 8 | * Copyright (C) 2000 - 2015, Intel Corp. |
1da177e4 LT |
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 | ||
839e928f LZ |
44 | #define EXPORT_ACPI_INTERFACES |
45 | ||
1da177e4 | 46 | #include <acpi/acpi.h> |
e2f7a777 | 47 | #include "accommon.h" |
1da177e4 LT |
48 | |
49 | #define _COMPONENT ACPI_HARDWARE | |
4be44fcd | 50 | ACPI_MODULE_NAME("hwtimer") |
1da177e4 | 51 | |
33620c54 | 52 | #if (!ACPI_REDUCED_HARDWARE) /* Entire module */ |
1da177e4 LT |
53 | /****************************************************************************** |
54 | * | |
55 | * FUNCTION: acpi_get_timer_resolution | |
56 | * | |
ba494bee | 57 | * PARAMETERS: resolution - Where the resolution is returned |
1da177e4 LT |
58 | * |
59 | * RETURN: Status and timer resolution | |
60 | * | |
61 | * DESCRIPTION: Obtains resolution of the ACPI PM Timer (24 or 32 bits). | |
62 | * | |
63 | ******************************************************************************/ | |
4be44fcd | 64 | acpi_status acpi_get_timer_resolution(u32 * resolution) |
1da177e4 | 65 | { |
b229cf92 | 66 | ACPI_FUNCTION_TRACE(acpi_get_timer_resolution); |
1da177e4 LT |
67 | |
68 | if (!resolution) { | |
4be44fcd | 69 | return_ACPI_STATUS(AE_BAD_PARAMETER); |
1da177e4 LT |
70 | } |
71 | ||
f3d2e786 | 72 | if ((acpi_gbl_FADT.flags & ACPI_FADT_32BIT_TIMER) == 0) { |
1da177e4 | 73 | *resolution = 24; |
4be44fcd | 74 | } else { |
1da177e4 LT |
75 | *resolution = 32; |
76 | } | |
77 | ||
4be44fcd | 78 | return_ACPI_STATUS(AE_OK); |
1da177e4 LT |
79 | } |
80 | ||
8313524a BM |
81 | ACPI_EXPORT_SYMBOL(acpi_get_timer_resolution) |
82 | ||
1da177e4 LT |
83 | /****************************************************************************** |
84 | * | |
85 | * FUNCTION: acpi_get_timer | |
86 | * | |
ba494bee | 87 | * PARAMETERS: ticks - Where the timer value is returned |
1da177e4 | 88 | * |
44f6c012 | 89 | * RETURN: Status and current timer value (ticks) |
1da177e4 LT |
90 | * |
91 | * DESCRIPTION: Obtains current value of ACPI PM Timer (in ticks). | |
92 | * | |
93 | ******************************************************************************/ | |
4be44fcd | 94 | acpi_status acpi_get_timer(u32 * ticks) |
1da177e4 | 95 | { |
4be44fcd | 96 | acpi_status status; |
1da177e4 | 97 | |
b229cf92 | 98 | ACPI_FUNCTION_TRACE(acpi_get_timer); |
1da177e4 LT |
99 | |
100 | if (!ticks) { | |
4be44fcd | 101 | return_ACPI_STATUS(AE_BAD_PARAMETER); |
1da177e4 LT |
102 | } |
103 | ||
1d82980c BM |
104 | /* ACPI 5.0A: PM Timer is optional */ |
105 | ||
106 | if (!acpi_gbl_FADT.xpm_timer_block.address) { | |
107 | return_ACPI_STATUS(AE_SUPPORT); | |
108 | } | |
1da177e4 | 109 | |
1d82980c | 110 | status = acpi_hw_read(ticks, &acpi_gbl_FADT.xpm_timer_block); |
4be44fcd | 111 | return_ACPI_STATUS(status); |
1da177e4 | 112 | } |
1da177e4 | 113 | |
8313524a | 114 | ACPI_EXPORT_SYMBOL(acpi_get_timer) |
1da177e4 LT |
115 | |
116 | /****************************************************************************** | |
117 | * | |
118 | * FUNCTION: acpi_get_timer_duration | |
119 | * | |
120 | * PARAMETERS: start_ticks - Starting timestamp | |
121 | * end_ticks - End timestamp | |
122 | * time_elapsed - Where the elapsed time is returned | |
123 | * | |
124 | * RETURN: Status and time_elapsed | |
125 | * | |
126 | * DESCRIPTION: Computes the time elapsed (in microseconds) between two | |
127 | * PM Timer time stamps, taking into account the possibility of | |
128 | * rollovers, the timer resolution, and timer frequency. | |
129 | * | |
130 | * The PM Timer's clock ticks at roughly 3.6 times per | |
131 | * _microsecond_, and its clock continues through Cx state | |
132 | * transitions (unlike many CPU timestamp counters) -- making it | |
133 | * a versatile and accurate timer. | |
134 | * | |
135 | * Note that this function accommodates only a single timer | |
73a3090a | 136 | * rollover. Thus for 24-bit timers, this function should only |
1da177e4 LT |
137 | * be used for calculating durations less than ~4.6 seconds |
138 | * (~20 minutes for 32-bit timers) -- calculations below: | |
139 | * | |
140 | * 2**24 Ticks / 3,600,000 Ticks/Sec = 4.66 sec | |
141 | * 2**32 Ticks / 3,600,000 Ticks/Sec = 1193 sec or 19.88 minutes | |
142 | * | |
143 | ******************************************************************************/ | |
1da177e4 | 144 | acpi_status |
4be44fcd | 145 | acpi_get_timer_duration(u32 start_ticks, u32 end_ticks, u32 * time_elapsed) |
1da177e4 | 146 | { |
4be44fcd LB |
147 | acpi_status status; |
148 | u32 delta_ticks; | |
5df7e6cb | 149 | u64 quotient; |
1da177e4 | 150 | |
b229cf92 | 151 | ACPI_FUNCTION_TRACE(acpi_get_timer_duration); |
1da177e4 LT |
152 | |
153 | if (!time_elapsed) { | |
4be44fcd | 154 | return_ACPI_STATUS(AE_BAD_PARAMETER); |
1da177e4 LT |
155 | } |
156 | ||
1d82980c BM |
157 | /* ACPI 5.0A: PM Timer is optional */ |
158 | ||
159 | if (!acpi_gbl_FADT.xpm_timer_block.address) { | |
160 | return_ACPI_STATUS(AE_SUPPORT); | |
161 | } | |
162 | ||
1da177e4 LT |
163 | /* |
164 | * Compute Tick Delta: | |
165 | * Handle (max one) timer rollovers on 24-bit versus 32-bit timers. | |
166 | */ | |
167 | if (start_ticks < end_ticks) { | |
168 | delta_ticks = end_ticks - start_ticks; | |
4be44fcd | 169 | } else if (start_ticks > end_ticks) { |
f3d2e786 | 170 | if ((acpi_gbl_FADT.flags & ACPI_FADT_32BIT_TIMER) == 0) { |
52fc0b02 | 171 | |
1da177e4 LT |
172 | /* 24-bit Timer */ |
173 | ||
4be44fcd LB |
174 | delta_ticks = |
175 | (((0x00FFFFFF - start_ticks) + | |
176 | end_ticks) & 0x00FFFFFF); | |
177 | } else { | |
1da177e4 LT |
178 | /* 32-bit Timer */ |
179 | ||
180 | delta_ticks = (0xFFFFFFFF - start_ticks) + end_ticks; | |
181 | } | |
4be44fcd LB |
182 | } else { /* start_ticks == end_ticks */ |
183 | ||
1da177e4 | 184 | *time_elapsed = 0; |
4be44fcd | 185 | return_ACPI_STATUS(AE_OK); |
1da177e4 LT |
186 | } |
187 | ||
188 | /* | |
189 | * Compute Duration (Requires a 64-bit multiply and divide): | |
190 | * | |
c41679a4 BM |
191 | * time_elapsed (microseconds) = |
192 | * (delta_ticks * ACPI_USEC_PER_SEC) / ACPI_PM_TIMER_FREQUENCY; | |
1da177e4 | 193 | */ |
c41679a4 BM |
194 | status = acpi_ut_short_divide(((u64)delta_ticks) * ACPI_USEC_PER_SEC, |
195 | ACPI_PM_TIMER_FREQUENCY, "ient, NULL); | |
1da177e4 LT |
196 | |
197 | *time_elapsed = (u32) quotient; | |
4be44fcd | 198 | return_ACPI_STATUS(status); |
1da177e4 | 199 | } |
44f6c012 | 200 | |
8313524a | 201 | ACPI_EXPORT_SYMBOL(acpi_get_timer_duration) |
33620c54 | 202 | #endif /* !ACPI_REDUCED_HARDWARE */ |