1 ACPI Time and Alarm (TAD) devi 1 ACPI Time and Alarm (TAD) device attributes.
2 2
3 What: /sys/bus/platform/devices/ACPI 3 What: /sys/bus/platform/devices/ACPI000E:00/caps
4 Date: March 2018 4 Date: March 2018
5 Contact: Rafael J. Wysocki <rafael.j.wys 5 Contact: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
6 Description: 6 Description:
7 (RO) Hexadecimal bitmask of th 7 (RO) Hexadecimal bitmask of the TAD attributes are reported by
8 the platform firmware (see ACP 8 the platform firmware (see ACPI 6.2, section 9.18.2):
9 9
10 ======= ====================== 10 ======= ======================================================
11 BIT(0): AC wakeup implemented 11 BIT(0): AC wakeup implemented if set
12 BIT(1): DC wakeup implemented 12 BIT(1): DC wakeup implemented if set
13 BIT(2): Get/set real time feat 13 BIT(2): Get/set real time features implemented if set
14 BIT(3): Real time accuracy in 14 BIT(3): Real time accuracy in milliseconds if set
15 BIT(4): Correct status reporte 15 BIT(4): Correct status reported for wakeups from S4/S5 if set
16 BIT(5): The AC timer wakes up 16 BIT(5): The AC timer wakes up from S4 if set
17 BIT(6): The AC timer wakes up 17 BIT(6): The AC timer wakes up from S5 if set
18 BIT(7): The DC timer wakes up 18 BIT(7): The DC timer wakes up from S4 if set
19 BIT(8): The DC timer wakes up 19 BIT(8): The DC timer wakes up from S5 if set
20 ======= ====================== 20 ======= ======================================================
21 21
22 The other bits are reserved. 22 The other bits are reserved.
23 23
24 What: /sys/bus/platform/devices/ACPI 24 What: /sys/bus/platform/devices/ACPI000E:00/ac_alarm
25 Date: March 2018 25 Date: March 2018
26 Contact: Rafael J. Wysocki <rafael.j.wys 26 Contact: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
27 Description: 27 Description:
28 (RW) The AC alarm timer value. 28 (RW) The AC alarm timer value.
29 29
30 Reads return the current AC al 30 Reads return the current AC alarm timer value in seconds or
31 "disabled", if the AC alarm is 31 "disabled", if the AC alarm is not set to wake up the system.
32 32
33 Write a new AC alarm timer val 33 Write a new AC alarm timer value in seconds or "disabled" to it
34 to set the AC alarm timer or t 34 to set the AC alarm timer or to disable it, respectively.
35 35
36 If the AC alarm timer is set t 36 If the AC alarm timer is set through this attribute and it
37 expires, it will immediately w 37 expires, it will immediately wake up the system from the S3
38 sleep state (and from S4/S5 to 38 sleep state (and from S4/S5 too if supported) until its status
39 is explicitly cleared via the 39 is explicitly cleared via the ac_status attribute.
40 40
41 What: /sys/bus/platform/devices/ACPI 41 What: /sys/bus/platform/devices/ACPI000E:00/ac_policy
42 Date: March 2018 42 Date: March 2018
43 Contact: Rafael J. Wysocki <rafael.j.wys 43 Contact: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
44 Description: 44 Description:
45 (RW) The AC alarm expired time 45 (RW) The AC alarm expired timer wake policy (see ACPI 6.2,
46 Section 9.18 for details). 46 Section 9.18 for details).
47 47
48 Reads return the current expir 48 Reads return the current expired timer wake delay for the AC
49 alarm timer or "never", if the 49 alarm timer or "never", if the policy is to discard AC timer
50 wakeups if the system is on DC 50 wakeups if the system is on DC power.
51 51
52 Write a new expired timer wake 52 Write a new expired timer wake delay for the AC alarm timer in
53 seconds or "never" to it to se 53 seconds or "never" to it to set the expired timer wake delay for
54 the AC alarm timer or to set i 54 the AC alarm timer or to set its expired wake policy to discard
55 wakeups if the system is on DC 55 wakeups if the system is on DC power, respectively.
56 56
57 What: /sys/bus/platform/devices/ACPI 57 What: /sys/bus/platform/devices/ACPI000E:00/ac_status
58 Date: March 2018 58 Date: March 2018
59 Contact: Rafael J. Wysocki <rafael.j.wys 59 Contact: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
60 Description: 60 Description:
61 (RW) The AC alarm status. 61 (RW) The AC alarm status.
62 62
63 Reads return a hexadecimal bit 63 Reads return a hexadecimal bitmask representing the AC alarm
64 timer status with the followin 64 timer status with the following meaning of bits (see ACPI 6.2,
65 Section 9.18.5): 65 Section 9.18.5):
66 66
67 ======= ====================== 67 ======= ======================================================
68 Bit(0): The timer has expired 68 Bit(0): The timer has expired if set.
69 Bit(1): The timer has woken up 69 Bit(1): The timer has woken up the system from a sleep state
70 (S3 or S4/S5 if suppor 70 (S3 or S4/S5 if supported) if set.
71 ======= ====================== 71 ======= ======================================================
72 72
73 The other bits are reserved. 73 The other bits are reserved.
74 74
75 Reads also cause the AC alarm 75 Reads also cause the AC alarm timer status to be reset.
76 76
77 Another way to reset the statu 77 Another way to reset the status of the AC alarm timer is to
78 write (the number) 0 to this f 78 write (the number) 0 to this file.
79 79
80 If the status return value ind 80 If the status return value indicates that the timer has expired,
81 it will immediately wake up th 81 it will immediately wake up the system from the S3 sleep state
82 (and from S4/S5 too if support 82 (and from S4/S5 too if supported) until its status is explicitly
83 cleared through this attribute 83 cleared through this attribute.
84 84
85 What: /sys/bus/platform/devices/ACPI 85 What: /sys/bus/platform/devices/ACPI000E:00/dc_alarm
86 Date: March 2018 86 Date: March 2018
87 Contact: Rafael J. Wysocki <rafael.j.wys 87 Contact: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
88 Description: 88 Description:
89 (RW,optional) The DC alarm tim 89 (RW,optional) The DC alarm timer value.
90 90
91 This attribute is only present 91 This attribute is only present if the TAD supports a separate
92 DC timer. 92 DC timer.
93 93
94 It is analogous to the ac_alar 94 It is analogous to the ac_alarm attribute.
95 95
96 What: /sys/bus/platform/devices/ACPI 96 What: /sys/bus/platform/devices/ACPI000E:00/dc_policy
97 Date: March 2018 97 Date: March 2018
98 Contact: Rafael J. Wysocki <rafael.j.wys 98 Contact: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
99 Description: 99 Description:
100 (RW,optional) The DC alarm exp 100 (RW,optional) The DC alarm expired timer wake policy.
101 101
102 This attribute is only present 102 This attribute is only present if the TAD supports a separate
103 DC timer. 103 DC timer.
104 104
105 It is analogous to the ac_poli 105 It is analogous to the ac_policy attribute.
106 106
107 What: /sys/bus/platform/devices/ACPI 107 What: /sys/bus/platform/devices/ACPI000E:00/dc_status
108 Date: March 2018 108 Date: March 2018
109 Contact: Rafael J. Wysocki <rafael.j.wys 109 Contact: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
110 110
111 Description: 111 Description:
112 (RW,optional) The DC alarm sta 112 (RW,optional) The DC alarm status.
113 113
114 This attribute is only present 114 This attribute is only present if the TAD supports a separate
115 DC timer. 115 DC timer.
116 116
117 It is analogous to the ac_stat 117 It is analogous to the ac_status attribute.
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