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