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1
2/******************************************************************************
3 *
4 * Name: hwtimer.c - ACPI Power Management Timer Interface
5 *
6 *****************************************************************************/
7
8/*
9 * Copyright (C) 2000 - 2011, Intel Corp.
10 * All rights reserved.
11 *
12 * Redistribution and use in source and binary forms, with or without
13 * modification, are permitted provided that the following conditions
14 * are met:
15 * 1. Redistributions of source code must retain the above copyright
16 * notice, this list of conditions, and the following disclaimer,
17 * without modification.
18 * 2. Redistributions in binary form must reproduce at minimum a disclaimer
19 * substantially similar to the "NO WARRANTY" disclaimer below
20 * ("Disclaimer") and any redistribution must be conditioned upon
21 * including a substantially similar Disclaimer requirement for further
22 * binary redistribution.
23 * 3. Neither the names of the above-listed copyright holders nor the names
24 * of any contributors may be used to endorse or promote products derived
25 * from this software without specific prior written permission.
26 *
27 * Alternatively, this software may be distributed under the terms of the
28 * GNU General Public License ("GPL") version 2 as published by the Free
29 * Software Foundation.
30 *
31 * NO WARRANTY
32 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
33 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
34 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTIBILITY AND FITNESS FOR
35 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
36 * HOLDERS OR CONTRIBUTORS BE LIABLE FOR SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
37 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
38 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
39 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
40 * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING
41 * IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
42 * POSSIBILITY OF SUCH DAMAGES.
43 */
44
45#include <acpi/acpi.h>
46#include "accommon.h"
47
48#define _COMPONENT ACPI_HARDWARE
49ACPI_MODULE_NAME("hwtimer")
50
51/******************************************************************************
52 *
53 * FUNCTION: acpi_get_timer_resolution
54 *
55 * PARAMETERS: Resolution - Where the resolution is returned
56 *
57 * RETURN: Status and timer resolution
58 *
59 * DESCRIPTION: Obtains resolution of the ACPI PM Timer (24 or 32 bits).
60 *
61 ******************************************************************************/
62acpi_status acpi_get_timer_resolution(u32 * resolution)
63{
64 ACPI_FUNCTION_TRACE(acpi_get_timer_resolution);
65
66 if (!resolution) {
67 return_ACPI_STATUS(AE_BAD_PARAMETER);
68 }
69
70 if ((acpi_gbl_FADT.flags & ACPI_FADT_32BIT_TIMER) == 0) {
71 *resolution = 24;
72 } else {
73 *resolution = 32;
74 }
75
76 return_ACPI_STATUS(AE_OK);
77}
78
79ACPI_EXPORT_SYMBOL(acpi_get_timer_resolution)
80
81/******************************************************************************
82 *
83 * FUNCTION: acpi_get_timer
84 *
85 * PARAMETERS: Ticks - Where the timer value is returned
86 *
87 * RETURN: Status and current timer value (ticks)
88 *
89 * DESCRIPTION: Obtains current value of ACPI PM Timer (in ticks).
90 *
91 ******************************************************************************/
92acpi_status acpi_get_timer(u32 * ticks)
93{
94 acpi_status status;
95
96 ACPI_FUNCTION_TRACE(acpi_get_timer);
97
98 if (!ticks) {
99 return_ACPI_STATUS(AE_BAD_PARAMETER);
100 }
101
102 status =
103 acpi_hw_read(ticks, &acpi_gbl_FADT.xpm_timer_block);
104
105 return_ACPI_STATUS(status);
106}
107
108ACPI_EXPORT_SYMBOL(acpi_get_timer)
109
110/******************************************************************************
111 *
112 * FUNCTION: acpi_get_timer_duration
113 *
114 * PARAMETERS: start_ticks - Starting timestamp
115 * end_ticks - End timestamp
116 * time_elapsed - Where the elapsed time is returned
117 *
118 * RETURN: Status and time_elapsed
119 *
120 * DESCRIPTION: Computes the time elapsed (in microseconds) between two
121 * PM Timer time stamps, taking into account the possibility of
122 * rollovers, the timer resolution, and timer frequency.
123 *
124 * The PM Timer's clock ticks at roughly 3.6 times per
125 * _microsecond_, and its clock continues through Cx state
126 * transitions (unlike many CPU timestamp counters) -- making it
127 * a versatile and accurate timer.
128 *
129 * Note that this function accommodates only a single timer
130 * rollover. Thus for 24-bit timers, this function should only
131 * be used for calculating durations less than ~4.6 seconds
132 * (~20 minutes for 32-bit timers) -- calculations below:
133 *
134 * 2**24 Ticks / 3,600,000 Ticks/Sec = 4.66 sec
135 * 2**32 Ticks / 3,600,000 Ticks/Sec = 1193 sec or 19.88 minutes
136 *
137 ******************************************************************************/
138acpi_status
139acpi_get_timer_duration(u32 start_ticks, u32 end_ticks, u32 * time_elapsed)
140{
141 acpi_status status;
142 u32 delta_ticks;
143 u64 quotient;
144
145 ACPI_FUNCTION_TRACE(acpi_get_timer_duration);
146
147 if (!time_elapsed) {
148 return_ACPI_STATUS(AE_BAD_PARAMETER);
149 }
150
151 /*
152 * Compute Tick Delta:
153 * Handle (max one) timer rollovers on 24-bit versus 32-bit timers.
154 */
155 if (start_ticks < end_ticks) {
156 delta_ticks = end_ticks - start_ticks;
157 } else if (start_ticks > end_ticks) {
158 if ((acpi_gbl_FADT.flags & ACPI_FADT_32BIT_TIMER) == 0) {
159
160 /* 24-bit Timer */
161
162 delta_ticks =
163 (((0x00FFFFFF - start_ticks) +
164 end_ticks) & 0x00FFFFFF);
165 } else {
166 /* 32-bit Timer */
167
168 delta_ticks = (0xFFFFFFFF - start_ticks) + end_ticks;
169 }
170 } else { /* start_ticks == end_ticks */
171
172 *time_elapsed = 0;
173 return_ACPI_STATUS(AE_OK);
174 }
175
176 /*
177 * Compute Duration (Requires a 64-bit multiply and divide):
178 *
179 * time_elapsed = (delta_ticks * 1000000) / PM_TIMER_FREQUENCY;
180 */
181 status = acpi_ut_short_divide(((u64) delta_ticks) * 1000000,
182 PM_TIMER_FREQUENCY, "ient, NULL);
183
184 *time_elapsed = (u32) quotient;
185 return_ACPI_STATUS(status);
186}
187
188ACPI_EXPORT_SYMBOL(acpi_get_timer_duration)
1// SPDX-License-Identifier: BSD-3-Clause OR GPL-2.0
2/******************************************************************************
3 *
4 * Name: hwtimer.c - ACPI Power Management Timer Interface
5 *
6 * Copyright (C) 2000 - 2019, Intel Corp.
7 *
8 *****************************************************************************/
9
10#define EXPORT_ACPI_INTERFACES
11
12#include <acpi/acpi.h>
13#include "accommon.h"
14
15#define _COMPONENT ACPI_HARDWARE
16ACPI_MODULE_NAME("hwtimer")
17
18#if (!ACPI_REDUCED_HARDWARE) /* Entire module */
19/******************************************************************************
20 *
21 * FUNCTION: acpi_get_timer_resolution
22 *
23 * PARAMETERS: resolution - Where the resolution is returned
24 *
25 * RETURN: Status and timer resolution
26 *
27 * DESCRIPTION: Obtains resolution of the ACPI PM Timer (24 or 32 bits).
28 *
29 ******************************************************************************/
30acpi_status acpi_get_timer_resolution(u32 * resolution)
31{
32 ACPI_FUNCTION_TRACE(acpi_get_timer_resolution);
33
34 if (!resolution) {
35 return_ACPI_STATUS(AE_BAD_PARAMETER);
36 }
37
38 if ((acpi_gbl_FADT.flags & ACPI_FADT_32BIT_TIMER) == 0) {
39 *resolution = 24;
40 } else {
41 *resolution = 32;
42 }
43
44 return_ACPI_STATUS(AE_OK);
45}
46
47ACPI_EXPORT_SYMBOL(acpi_get_timer_resolution)
48
49/******************************************************************************
50 *
51 * FUNCTION: acpi_get_timer
52 *
53 * PARAMETERS: ticks - Where the timer value is returned
54 *
55 * RETURN: Status and current timer value (ticks)
56 *
57 * DESCRIPTION: Obtains current value of ACPI PM Timer (in ticks).
58 *
59 ******************************************************************************/
60acpi_status acpi_get_timer(u32 * ticks)
61{
62 acpi_status status;
63 u64 timer_value;
64
65 ACPI_FUNCTION_TRACE(acpi_get_timer);
66
67 if (!ticks) {
68 return_ACPI_STATUS(AE_BAD_PARAMETER);
69 }
70
71 /* ACPI 5.0A: PM Timer is optional */
72
73 if (!acpi_gbl_FADT.xpm_timer_block.address) {
74 return_ACPI_STATUS(AE_SUPPORT);
75 }
76
77 status = acpi_hw_read(&timer_value, &acpi_gbl_FADT.xpm_timer_block);
78 if (ACPI_SUCCESS(status)) {
79
80 /* ACPI PM Timer is defined to be 32 bits (PM_TMR_LEN) */
81
82 *ticks = (u32)timer_value;
83 }
84
85 return_ACPI_STATUS(status);
86}
87
88ACPI_EXPORT_SYMBOL(acpi_get_timer)
89
90/******************************************************************************
91 *
92 * FUNCTION: acpi_get_timer_duration
93 *
94 * PARAMETERS: start_ticks - Starting timestamp
95 * end_ticks - End timestamp
96 * time_elapsed - Where the elapsed time is returned
97 *
98 * RETURN: Status and time_elapsed
99 *
100 * DESCRIPTION: Computes the time elapsed (in microseconds) between two
101 * PM Timer time stamps, taking into account the possibility of
102 * rollovers, the timer resolution, and timer frequency.
103 *
104 * The PM Timer's clock ticks at roughly 3.6 times per
105 * _microsecond_, and its clock continues through Cx state
106 * transitions (unlike many CPU timestamp counters) -- making it
107 * a versatile and accurate timer.
108 *
109 * Note that this function accommodates only a single timer
110 * rollover. Thus for 24-bit timers, this function should only
111 * be used for calculating durations less than ~4.6 seconds
112 * (~20 minutes for 32-bit timers) -- calculations below:
113 *
114 * 2**24 Ticks / 3,600,000 Ticks/Sec = 4.66 sec
115 * 2**32 Ticks / 3,600,000 Ticks/Sec = 1193 sec or 19.88 minutes
116 *
117 ******************************************************************************/
118acpi_status
119acpi_get_timer_duration(u32 start_ticks, u32 end_ticks, u32 *time_elapsed)
120{
121 acpi_status status;
122 u64 delta_ticks;
123 u64 quotient;
124
125 ACPI_FUNCTION_TRACE(acpi_get_timer_duration);
126
127 if (!time_elapsed) {
128 return_ACPI_STATUS(AE_BAD_PARAMETER);
129 }
130
131 /* ACPI 5.0A: PM Timer is optional */
132
133 if (!acpi_gbl_FADT.xpm_timer_block.address) {
134 return_ACPI_STATUS(AE_SUPPORT);
135 }
136
137 if (start_ticks == end_ticks) {
138 *time_elapsed = 0;
139 return_ACPI_STATUS(AE_OK);
140 }
141
142 /*
143 * Compute Tick Delta:
144 * Handle (max one) timer rollovers on 24-bit versus 32-bit timers.
145 */
146 delta_ticks = end_ticks;
147 if (start_ticks > end_ticks) {
148 if ((acpi_gbl_FADT.flags & ACPI_FADT_32BIT_TIMER) == 0) {
149
150 /* 24-bit Timer */
151
152 delta_ticks |= (u64)1 << 24;
153 } else {
154 /* 32-bit Timer */
155
156 delta_ticks |= (u64)1 << 32;
157 }
158 }
159 delta_ticks -= start_ticks;
160
161 /*
162 * Compute Duration (Requires a 64-bit multiply and divide):
163 *
164 * time_elapsed (microseconds) =
165 * (delta_ticks * ACPI_USEC_PER_SEC) / ACPI_PM_TIMER_FREQUENCY;
166 */
167 status = acpi_ut_short_divide(delta_ticks * ACPI_USEC_PER_SEC,
168 ACPI_PM_TIMER_FREQUENCY, "ient, NULL);
169
170 *time_elapsed = (u32)quotient;
171 return_ACPI_STATUS(status);
172}
173
174ACPI_EXPORT_SYMBOL(acpi_get_timer_duration)
175#endif /* !ACPI_REDUCED_HARDWARE */