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95857638 | 1 | // SPDX-License-Identifier: BSD-3-Clause OR GPL-2.0 |
1da177e4 LT |
2 | /****************************************************************************** |
3 | * | |
4 | * Name: hwtimer.c - ACPI Power Management Timer Interface | |
5 | * | |
800ba7c5 | 6 | * Copyright (C) 2000 - 2020, Intel Corp. |
1da177e4 | 7 | * |
95857638 | 8 | *****************************************************************************/ |
1da177e4 | 9 | |
839e928f LZ |
10 | #define EXPORT_ACPI_INTERFACES |
11 | ||
1da177e4 | 12 | #include <acpi/acpi.h> |
e2f7a777 | 13 | #include "accommon.h" |
1da177e4 LT |
14 | |
15 | #define _COMPONENT ACPI_HARDWARE | |
4be44fcd | 16 | ACPI_MODULE_NAME("hwtimer") |
1da177e4 | 17 | |
33620c54 | 18 | #if (!ACPI_REDUCED_HARDWARE) /* Entire module */ |
1da177e4 LT |
19 | /****************************************************************************** |
20 | * | |
21 | * FUNCTION: acpi_get_timer_resolution | |
22 | * | |
ba494bee | 23 | * PARAMETERS: resolution - Where the resolution is returned |
1da177e4 LT |
24 | * |
25 | * RETURN: Status and timer resolution | |
26 | * | |
27 | * DESCRIPTION: Obtains resolution of the ACPI PM Timer (24 or 32 bits). | |
28 | * | |
29 | ******************************************************************************/ | |
4be44fcd | 30 | acpi_status acpi_get_timer_resolution(u32 * resolution) |
1da177e4 | 31 | { |
b229cf92 | 32 | ACPI_FUNCTION_TRACE(acpi_get_timer_resolution); |
1da177e4 LT |
33 | |
34 | if (!resolution) { | |
4be44fcd | 35 | return_ACPI_STATUS(AE_BAD_PARAMETER); |
1da177e4 LT |
36 | } |
37 | ||
f3d2e786 | 38 | if ((acpi_gbl_FADT.flags & ACPI_FADT_32BIT_TIMER) == 0) { |
1da177e4 | 39 | *resolution = 24; |
4be44fcd | 40 | } else { |
1da177e4 LT |
41 | *resolution = 32; |
42 | } | |
43 | ||
4be44fcd | 44 | return_ACPI_STATUS(AE_OK); |
1da177e4 LT |
45 | } |
46 | ||
8313524a BM |
47 | ACPI_EXPORT_SYMBOL(acpi_get_timer_resolution) |
48 | ||
1da177e4 LT |
49 | /****************************************************************************** |
50 | * | |
51 | * FUNCTION: acpi_get_timer | |
52 | * | |
ba494bee | 53 | * PARAMETERS: ticks - Where the timer value is returned |
1da177e4 | 54 | * |
44f6c012 | 55 | * RETURN: Status and current timer value (ticks) |
1da177e4 LT |
56 | * |
57 | * DESCRIPTION: Obtains current value of ACPI PM Timer (in ticks). | |
58 | * | |
59 | ******************************************************************************/ | |
4be44fcd | 60 | acpi_status acpi_get_timer(u32 * ticks) |
1da177e4 | 61 | { |
4be44fcd | 62 | acpi_status status; |
8092936d | 63 | u64 timer_value; |
1da177e4 | 64 | |
b229cf92 | 65 | ACPI_FUNCTION_TRACE(acpi_get_timer); |
1da177e4 LT |
66 | |
67 | if (!ticks) { | |
4be44fcd | 68 | return_ACPI_STATUS(AE_BAD_PARAMETER); |
1da177e4 LT |
69 | } |
70 | ||
1d82980c BM |
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 | } | |
1da177e4 | 76 | |
8092936d BM |
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 | ||
4be44fcd | 85 | return_ACPI_STATUS(status); |
1da177e4 | 86 | } |
1da177e4 | 87 | |
8313524a | 88 | ACPI_EXPORT_SYMBOL(acpi_get_timer) |
1da177e4 LT |
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 | |
73a3090a | 110 | * rollover. Thus for 24-bit timers, this function should only |
1da177e4 LT |
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 | ******************************************************************************/ | |
1da177e4 | 118 | acpi_status |
8f275615 | 119 | acpi_get_timer_duration(u32 start_ticks, u32 end_ticks, u32 *time_elapsed) |
1da177e4 | 120 | { |
4be44fcd | 121 | acpi_status status; |
8f275615 | 122 | u64 delta_ticks; |
5df7e6cb | 123 | u64 quotient; |
1da177e4 | 124 | |
b229cf92 | 125 | ACPI_FUNCTION_TRACE(acpi_get_timer_duration); |
1da177e4 LT |
126 | |
127 | if (!time_elapsed) { | |
4be44fcd | 128 | return_ACPI_STATUS(AE_BAD_PARAMETER); |
1da177e4 LT |
129 | } |
130 | ||
1d82980c BM |
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 | ||
8f275615 JK |
137 | if (start_ticks == end_ticks) { |
138 | *time_elapsed = 0; | |
139 | return_ACPI_STATUS(AE_OK); | |
140 | } | |
141 | ||
1da177e4 LT |
142 | /* |
143 | * Compute Tick Delta: | |
144 | * Handle (max one) timer rollovers on 24-bit versus 32-bit timers. | |
145 | */ | |
8f275615 JK |
146 | delta_ticks = end_ticks; |
147 | if (start_ticks > end_ticks) { | |
f3d2e786 | 148 | if ((acpi_gbl_FADT.flags & ACPI_FADT_32BIT_TIMER) == 0) { |
52fc0b02 | 149 | |
1da177e4 LT |
150 | /* 24-bit Timer */ |
151 | ||
8f275615 | 152 | delta_ticks |= (u64)1 << 24; |
4be44fcd | 153 | } else { |
1da177e4 LT |
154 | /* 32-bit Timer */ |
155 | ||
8f275615 | 156 | delta_ticks |= (u64)1 << 32; |
1da177e4 | 157 | } |
1da177e4 | 158 | } |
8f275615 | 159 | delta_ticks -= start_ticks; |
1da177e4 LT |
160 | |
161 | /* | |
162 | * Compute Duration (Requires a 64-bit multiply and divide): | |
163 | * | |
c41679a4 BM |
164 | * time_elapsed (microseconds) = |
165 | * (delta_ticks * ACPI_USEC_PER_SEC) / ACPI_PM_TIMER_FREQUENCY; | |
1da177e4 | 166 | */ |
8f275615 | 167 | status = acpi_ut_short_divide(delta_ticks * ACPI_USEC_PER_SEC, |
c41679a4 | 168 | ACPI_PM_TIMER_FREQUENCY, "ient, NULL); |
1da177e4 | 169 | |
8f275615 | 170 | *time_elapsed = (u32)quotient; |
4be44fcd | 171 | return_ACPI_STATUS(status); |
1da177e4 | 172 | } |
44f6c012 | 173 | |
8313524a | 174 | ACPI_EXPORT_SYMBOL(acpi_get_timer_duration) |
33620c54 | 175 | #endif /* !ACPI_REDUCED_HARDWARE */ |