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1
2/******************************************************************************
3 *
4 * Name: hwtimer.c - ACPI Power Management Timer Interface
5 *
6 *****************************************************************************/
7
8/*
9 * Copyright (C) 2000 - 2012, 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 <linux/export.h>
46#include <acpi/acpi.h>
47#include "accommon.h"
48
49#define _COMPONENT ACPI_HARDWARE
50ACPI_MODULE_NAME("hwtimer")
51
52#if (!ACPI_REDUCED_HARDWARE) /* Entire module */
53/******************************************************************************
54 *
55 * FUNCTION: acpi_get_timer_resolution
56 *
57 * PARAMETERS: Resolution - Where the resolution is returned
58 *
59 * RETURN: Status and timer resolution
60 *
61 * DESCRIPTION: Obtains resolution of the ACPI PM Timer (24 or 32 bits).
62 *
63 ******************************************************************************/
64acpi_status acpi_get_timer_resolution(u32 * resolution)
65{
66 ACPI_FUNCTION_TRACE(acpi_get_timer_resolution);
67
68 if (!resolution) {
69 return_ACPI_STATUS(AE_BAD_PARAMETER);
70 }
71
72 if ((acpi_gbl_FADT.flags & ACPI_FADT_32BIT_TIMER) == 0) {
73 *resolution = 24;
74 } else {
75 *resolution = 32;
76 }
77
78 return_ACPI_STATUS(AE_OK);
79}
80
81ACPI_EXPORT_SYMBOL(acpi_get_timer_resolution)
82
83/******************************************************************************
84 *
85 * FUNCTION: acpi_get_timer
86 *
87 * PARAMETERS: Ticks - Where the timer value is returned
88 *
89 * RETURN: Status and current timer value (ticks)
90 *
91 * DESCRIPTION: Obtains current value of ACPI PM Timer (in ticks).
92 *
93 ******************************************************************************/
94acpi_status acpi_get_timer(u32 * ticks)
95{
96 acpi_status status;
97
98 ACPI_FUNCTION_TRACE(acpi_get_timer);
99
100 if (!ticks) {
101 return_ACPI_STATUS(AE_BAD_PARAMETER);
102 }
103
104 status =
105 acpi_hw_read(ticks, &acpi_gbl_FADT.xpm_timer_block);
106
107 return_ACPI_STATUS(status);
108}
109
110ACPI_EXPORT_SYMBOL(acpi_get_timer)
111
112/******************************************************************************
113 *
114 * FUNCTION: acpi_get_timer_duration
115 *
116 * PARAMETERS: start_ticks - Starting timestamp
117 * end_ticks - End timestamp
118 * time_elapsed - Where the elapsed time is returned
119 *
120 * RETURN: Status and time_elapsed
121 *
122 * DESCRIPTION: Computes the time elapsed (in microseconds) between two
123 * PM Timer time stamps, taking into account the possibility of
124 * rollovers, the timer resolution, and timer frequency.
125 *
126 * The PM Timer's clock ticks at roughly 3.6 times per
127 * _microsecond_, and its clock continues through Cx state
128 * transitions (unlike many CPU timestamp counters) -- making it
129 * a versatile and accurate timer.
130 *
131 * Note that this function accommodates only a single timer
132 * rollover. Thus for 24-bit timers, this function should only
133 * be used for calculating durations less than ~4.6 seconds
134 * (~20 minutes for 32-bit timers) -- calculations below:
135 *
136 * 2**24 Ticks / 3,600,000 Ticks/Sec = 4.66 sec
137 * 2**32 Ticks / 3,600,000 Ticks/Sec = 1193 sec or 19.88 minutes
138 *
139 ******************************************************************************/
140acpi_status
141acpi_get_timer_duration(u32 start_ticks, u32 end_ticks, u32 * time_elapsed)
142{
143 acpi_status status;
144 u32 delta_ticks;
145 u64 quotient;
146
147 ACPI_FUNCTION_TRACE(acpi_get_timer_duration);
148
149 if (!time_elapsed) {
150 return_ACPI_STATUS(AE_BAD_PARAMETER);
151 }
152
153 /*
154 * Compute Tick Delta:
155 * Handle (max one) timer rollovers on 24-bit versus 32-bit timers.
156 */
157 if (start_ticks < end_ticks) {
158 delta_ticks = end_ticks - start_ticks;
159 } else if (start_ticks > end_ticks) {
160 if ((acpi_gbl_FADT.flags & ACPI_FADT_32BIT_TIMER) == 0) {
161
162 /* 24-bit Timer */
163
164 delta_ticks =
165 (((0x00FFFFFF - start_ticks) +
166 end_ticks) & 0x00FFFFFF);
167 } else {
168 /* 32-bit Timer */
169
170 delta_ticks = (0xFFFFFFFF - start_ticks) + end_ticks;
171 }
172 } else { /* start_ticks == end_ticks */
173
174 *time_elapsed = 0;
175 return_ACPI_STATUS(AE_OK);
176 }
177
178 /*
179 * Compute Duration (Requires a 64-bit multiply and divide):
180 *
181 * time_elapsed = (delta_ticks * 1000000) / PM_TIMER_FREQUENCY;
182 */
183 status = acpi_ut_short_divide(((u64) delta_ticks) * 1000000,
184 PM_TIMER_FREQUENCY, "ient, NULL);
185
186 *time_elapsed = (u32) quotient;
187 return_ACPI_STATUS(status);
188}
189
190ACPI_EXPORT_SYMBOL(acpi_get_timer_duration)
191#endif /* !ACPI_REDUCED_HARDWARE */
1/******************************************************************************
2 *
3 * Name: hwtimer.c - ACPI Power Management Timer Interface
4 *
5 *****************************************************************************/
6
7/*
8 * Copyright (C) 2000 - 2014, 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/acpi.h>
47#include "accommon.h"
48
49#define _COMPONENT ACPI_HARDWARE
50ACPI_MODULE_NAME("hwtimer")
51
52#if (!ACPI_REDUCED_HARDWARE) /* Entire module */
53/******************************************************************************
54 *
55 * FUNCTION: acpi_get_timer_resolution
56 *
57 * PARAMETERS: resolution - Where the resolution is returned
58 *
59 * RETURN: Status and timer resolution
60 *
61 * DESCRIPTION: Obtains resolution of the ACPI PM Timer (24 or 32 bits).
62 *
63 ******************************************************************************/
64acpi_status acpi_get_timer_resolution(u32 * resolution)
65{
66 ACPI_FUNCTION_TRACE(acpi_get_timer_resolution);
67
68 if (!resolution) {
69 return_ACPI_STATUS(AE_BAD_PARAMETER);
70 }
71
72 if ((acpi_gbl_FADT.flags & ACPI_FADT_32BIT_TIMER) == 0) {
73 *resolution = 24;
74 } else {
75 *resolution = 32;
76 }
77
78 return_ACPI_STATUS(AE_OK);
79}
80
81ACPI_EXPORT_SYMBOL(acpi_get_timer_resolution)
82
83/******************************************************************************
84 *
85 * FUNCTION: acpi_get_timer
86 *
87 * PARAMETERS: ticks - Where the timer value is returned
88 *
89 * RETURN: Status and current timer value (ticks)
90 *
91 * DESCRIPTION: Obtains current value of ACPI PM Timer (in ticks).
92 *
93 ******************************************************************************/
94acpi_status acpi_get_timer(u32 * ticks)
95{
96 acpi_status status;
97
98 ACPI_FUNCTION_TRACE(acpi_get_timer);
99
100 if (!ticks) {
101 return_ACPI_STATUS(AE_BAD_PARAMETER);
102 }
103
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 }
109
110 status = acpi_hw_read(ticks, &acpi_gbl_FADT.xpm_timer_block);
111 return_ACPI_STATUS(status);
112}
113
114ACPI_EXPORT_SYMBOL(acpi_get_timer)
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
136 * rollover. Thus for 24-bit timers, this function should only
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 ******************************************************************************/
144acpi_status
145acpi_get_timer_duration(u32 start_ticks, u32 end_ticks, u32 * time_elapsed)
146{
147 acpi_status status;
148 u32 delta_ticks;
149 u64 quotient;
150
151 ACPI_FUNCTION_TRACE(acpi_get_timer_duration);
152
153 if (!time_elapsed) {
154 return_ACPI_STATUS(AE_BAD_PARAMETER);
155 }
156
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
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;
169 } else if (start_ticks > end_ticks) {
170 if ((acpi_gbl_FADT.flags & ACPI_FADT_32BIT_TIMER) == 0) {
171
172 /* 24-bit Timer */
173
174 delta_ticks =
175 (((0x00FFFFFF - start_ticks) +
176 end_ticks) & 0x00FFFFFF);
177 } else {
178 /* 32-bit Timer */
179
180 delta_ticks = (0xFFFFFFFF - start_ticks) + end_ticks;
181 }
182 } else { /* start_ticks == end_ticks */
183
184 *time_elapsed = 0;
185 return_ACPI_STATUS(AE_OK);
186 }
187
188 /*
189 * Compute Duration (Requires a 64-bit multiply and divide):
190 *
191 * time_elapsed (microseconds) =
192 * (delta_ticks * ACPI_USEC_PER_SEC) / ACPI_PM_TIMER_FREQUENCY;
193 */
194 status = acpi_ut_short_divide(((u64)delta_ticks) * ACPI_USEC_PER_SEC,
195 ACPI_PM_TIMER_FREQUENCY, "ient, NULL);
196
197 *time_elapsed = (u32) quotient;
198 return_ACPI_STATUS(status);
199}
200
201ACPI_EXPORT_SYMBOL(acpi_get_timer_duration)
202#endif /* !ACPI_REDUCED_HARDWARE */