1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
|
/******************************************************************************
*
* Name: hwtimer.c - ACPI Power Management Timer Interface
*
*****************************************************************************/
/*
* Copyright (C) 2000 - 2012, Intel Corp.
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions, and the following disclaimer,
* without modification.
* 2. Redistributions in binary form must reproduce at minimum a disclaimer
* substantially similar to the "NO WARRANTY" disclaimer below
* ("Disclaimer") and any redistribution must be conditioned upon
* including a substantially similar Disclaimer requirement for further
* binary redistribution.
* 3. Neither the names of the above-listed copyright holders nor the names
* of any contributors may be used to endorse or promote products derived
* from this software without specific prior written permission.
*
* Alternatively, this software may be distributed under the terms of the
* GNU General Public License ("GPL") version 2 as published by the Free
* Software Foundation.
*
* NO WARRANTY
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
* "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTIBILITY AND FITNESS FOR
* A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
* HOLDERS OR CONTRIBUTORS BE LIABLE FOR SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
* STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING
* IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
* POSSIBILITY OF SUCH DAMAGES.
*/
#include <linux/export.h>
#include <acpi/acpi.h>
#include "accommon.h"
#define _COMPONENT ACPI_HARDWARE
ACPI_MODULE_NAME("hwtimer")
#if (!ACPI_REDUCED_HARDWARE) /* Entire module */
/******************************************************************************
*
* FUNCTION: acpi_get_timer_resolution
*
* PARAMETERS: resolution - Where the resolution is returned
*
* RETURN: Status and timer resolution
*
* DESCRIPTION: Obtains resolution of the ACPI PM Timer (24 or 32 bits).
*
******************************************************************************/
acpi_status acpi_get_timer_resolution(u32 * resolution)
{
ACPI_FUNCTION_TRACE(acpi_get_timer_resolution);
if (!resolution) {
return_ACPI_STATUS(AE_BAD_PARAMETER);
}
if ((acpi_gbl_FADT.flags & ACPI_FADT_32BIT_TIMER) == 0) {
*resolution = 24;
} else {
*resolution = 32;
}
return_ACPI_STATUS(AE_OK);
}
ACPI_EXPORT_SYMBOL(acpi_get_timer_resolution)
/******************************************************************************
*
* FUNCTION: acpi_get_timer
*
* PARAMETERS: ticks - Where the timer value is returned
*
* RETURN: Status and current timer value (ticks)
*
* DESCRIPTION: Obtains current value of ACPI PM Timer (in ticks).
*
******************************************************************************/
acpi_status acpi_get_timer(u32 * ticks)
{
acpi_status status;
ACPI_FUNCTION_TRACE(acpi_get_timer);
if (!ticks) {
return_ACPI_STATUS(AE_BAD_PARAMETER);
}
status = acpi_hw_read(ticks, &acpi_gbl_FADT.xpm_timer_block);
return_ACPI_STATUS(status);
}
ACPI_EXPORT_SYMBOL(acpi_get_timer)
/******************************************************************************
*
* FUNCTION: acpi_get_timer_duration
*
* PARAMETERS: start_ticks - Starting timestamp
* end_ticks - End timestamp
* time_elapsed - Where the elapsed time is returned
*
* RETURN: Status and time_elapsed
*
* DESCRIPTION: Computes the time elapsed (in microseconds) between two
* PM Timer time stamps, taking into account the possibility of
* rollovers, the timer resolution, and timer frequency.
*
* The PM Timer's clock ticks at roughly 3.6 times per
* _microsecond_, and its clock continues through Cx state
* transitions (unlike many CPU timestamp counters) -- making it
* a versatile and accurate timer.
*
* Note that this function accommodates only a single timer
* rollover. Thus for 24-bit timers, this function should only
* be used for calculating durations less than ~4.6 seconds
* (~20 minutes for 32-bit timers) -- calculations below:
*
* 2**24 Ticks / 3,600,000 Ticks/Sec = 4.66 sec
* 2**32 Ticks / 3,600,000 Ticks/Sec = 1193 sec or 19.88 minutes
*
******************************************************************************/
acpi_status
acpi_get_timer_duration(u32 start_ticks, u32 end_ticks, u32 * time_elapsed)
{
acpi_status status;
u32 delta_ticks;
u64 quotient;
ACPI_FUNCTION_TRACE(acpi_get_timer_duration);
if (!time_elapsed) {
return_ACPI_STATUS(AE_BAD_PARAMETER);
}
/*
* Compute Tick Delta:
* Handle (max one) timer rollovers on 24-bit versus 32-bit timers.
*/
if (start_ticks < end_ticks) {
delta_ticks = end_ticks - start_ticks;
} else if (start_ticks > end_ticks) {
if ((acpi_gbl_FADT.flags & ACPI_FADT_32BIT_TIMER) == 0) {
/* 24-bit Timer */
delta_ticks =
(((0x00FFFFFF - start_ticks) +
end_ticks) & 0x00FFFFFF);
} else {
/* 32-bit Timer */
delta_ticks = (0xFFFFFFFF - start_ticks) + end_ticks;
}
} else { /* start_ticks == end_ticks */
*time_elapsed = 0;
return_ACPI_STATUS(AE_OK);
}
/*
* Compute Duration (Requires a 64-bit multiply and divide):
*
* time_elapsed = (delta_ticks * 1000000) / PM_TIMER_FREQUENCY;
*/
status = acpi_ut_short_divide(((u64) delta_ticks) * 1000000,
PM_TIMER_FREQUENCY, "ient, NULL);
*time_elapsed = (u32) quotient;
return_ACPI_STATUS(status);
}
ACPI_EXPORT_SYMBOL(acpi_get_timer_duration)
#endif /* !ACPI_REDUCED_HARDWARE */
|
