1 What: /sys/class/rtc/ 1 What: /sys/class/rtc/
2 Date: March 2006 2 Date: March 2006
3 KernelVersion: 2.6.17 3 KernelVersion: 2.6.17
4 Contact: linux-rtc@vger.kernel.org 4 Contact: linux-rtc@vger.kernel.org
5 Description: 5 Description:
6 The rtc/ class subdirectory be 6 The rtc/ class subdirectory belongs to the RTC subsystem.
7 7
8 What: /sys/class/rtc/rtcX/ 8 What: /sys/class/rtc/rtcX/
9 Date: March 2006 9 Date: March 2006
10 KernelVersion: 2.6.17 10 KernelVersion: 2.6.17
11 Contact: linux-rtc@vger.kernel.org 11 Contact: linux-rtc@vger.kernel.org
12 Description: 12 Description:
13 The /sys/class/rtc/rtc{0,1,2,3 13 The /sys/class/rtc/rtc{0,1,2,3,...} directories correspond
14 to each RTC device. 14 to each RTC device.
15 15
16 What: /sys/class/rtc/rtcX/date 16 What: /sys/class/rtc/rtcX/date
17 Date: March 2006 17 Date: March 2006
18 KernelVersion: 2.6.17 18 KernelVersion: 2.6.17
19 Contact: linux-rtc@vger.kernel.org 19 Contact: linux-rtc@vger.kernel.org
20 Description: 20 Description:
21 (RO) RTC-provided date in YYYY 21 (RO) RTC-provided date in YYYY-MM-DD format
22 22
23 What: /sys/class/rtc/rtcX/hctosys 23 What: /sys/class/rtc/rtcX/hctosys
24 Date: September 2009 24 Date: September 2009
25 KernelVersion: 2.6.32 25 KernelVersion: 2.6.32
26 Contact: linux-rtc@vger.kernel.org 26 Contact: linux-rtc@vger.kernel.org
27 Description: 27 Description:
28 (RO) 1 if the RTC provided the 28 (RO) 1 if the RTC provided the system time at boot via the
29 CONFIG_RTC_HCTOSYS kernel opti 29 CONFIG_RTC_HCTOSYS kernel option, 0 otherwise
30 30
31 What: /sys/class/rtc/rtcX/max_user_f 31 What: /sys/class/rtc/rtcX/max_user_freq
32 Date: October 2007 32 Date: October 2007
33 KernelVersion: 2.6.24 33 KernelVersion: 2.6.24
34 Contact: linux-rtc@vger.kernel.org 34 Contact: linux-rtc@vger.kernel.org
35 Description: 35 Description:
36 (RW) The maximum interrupt rat 36 (RW) The maximum interrupt rate an unprivileged user may request
37 from this RTC. 37 from this RTC.
38 38
39 What: /sys/class/rtc/rtcX/name 39 What: /sys/class/rtc/rtcX/name
40 Date: March 2006 40 Date: March 2006
41 KernelVersion: 2.6.17 41 KernelVersion: 2.6.17
42 Contact: linux-rtc@vger.kernel.org 42 Contact: linux-rtc@vger.kernel.org
43 Description: 43 Description:
44 (RO) The name of the RTC corre 44 (RO) The name of the RTC corresponding to this sysfs directory
45 45
46 What: /sys/class/rtc/rtcX/range 46 What: /sys/class/rtc/rtcX/range
47 Date: January 2018 47 Date: January 2018
48 KernelVersion: 4.16 48 KernelVersion: 4.16
49 Contact: linux-rtc@vger.kernel.org 49 Contact: linux-rtc@vger.kernel.org
50 Description: 50 Description:
51 Valid time range for the RTC, 51 Valid time range for the RTC, as seconds from epoch, formatted
52 as [min, max] 52 as [min, max]
53 53
54 What: /sys/class/rtc/rtcX/since_epoc 54 What: /sys/class/rtc/rtcX/since_epoch
55 Date: March 2006 55 Date: March 2006
56 KernelVersion: 2.6.17 56 KernelVersion: 2.6.17
57 Contact: linux-rtc@vger.kernel.org 57 Contact: linux-rtc@vger.kernel.org
58 Description: 58 Description:
59 (RO) RTC-provided time as the 59 (RO) RTC-provided time as the number of seconds since the epoch
60 60
61 What: /sys/class/rtc/rtcX/time 61 What: /sys/class/rtc/rtcX/time
62 Date: March 2006 62 Date: March 2006
63 KernelVersion: 2.6.17 63 KernelVersion: 2.6.17
64 Contact: linux-rtc@vger.kernel.org 64 Contact: linux-rtc@vger.kernel.org
65 Description: 65 Description:
66 (RO) RTC-provided time in 24-h 66 (RO) RTC-provided time in 24-hour notation (hh:mm:ss)
67 67
68 What: /sys/class/rtc/rtcX/offset 68 What: /sys/class/rtc/rtcX/offset
69 Date: February 2016 69 Date: February 2016
70 KernelVersion: 4.6 70 KernelVersion: 4.6
71 Contact: linux-rtc@vger.kernel.org 71 Contact: linux-rtc@vger.kernel.org
72 Description: 72 Description:
73 (RW) The amount which the rtc 73 (RW) The amount which the rtc clock has been adjusted in
74 firmware. Visible only if the 74 firmware. Visible only if the driver supports clock offset
75 adjustment. The unit is parts 75 adjustment. The unit is parts per billion, i.e. The number of
76 clock ticks which are added to 76 clock ticks which are added to or removed from the rtc's base
77 clock per billion ticks. A pos 77 clock per billion ticks. A positive value makes a day pass more
78 slowly, longer, and a negative 78 slowly, longer, and a negative value makes a day pass more
79 quickly. 79 quickly.
80 80
81 What: /sys/class/rtc/rtcX/wakealarm 81 What: /sys/class/rtc/rtcX/wakealarm
82 Date: February 2007 82 Date: February 2007
83 KernelVersion: 2.6.20 83 KernelVersion: 2.6.20
84 Contact: linux-rtc@vger.kernel.org 84 Contact: linux-rtc@vger.kernel.org
85 Description: 85 Description:
86 (RW) The time at which the clo 86 (RW) The time at which the clock will generate a system wakeup
87 event. This is a one shot wake 87 event. This is a one shot wakeup event, so must be reset after
88 wake if a daily wakeup is requ 88 wake if a daily wakeup is required. Format is seconds since the
89 epoch by default, or if there' 89 epoch by default, or if there's a leading +, seconds in the
90 future, or if there is a leadi 90 future, or if there is a leading +=, seconds ahead of the
91 current alarm. 91 current alarm.
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