1What:		/sys/class/devfreq/.../
2Date:		September 2011
3Contact:	MyungJoo Ham <myungjoo.ham@samsung.com>
4Description:
5		Provide a place in sysfs for the devfreq objects.
6		This allows accessing various devfreq specific variables.
7		The name of devfreq object denoted as ... is same as the
8		name of device using devfreq.
9
10What:		/sys/class/devfreq/.../name
11Date:		November 2019
12Contact:	Chanwoo Choi <cw00.choi@samsung.com>
13Description:
14		The /sys/class/devfreq/.../name shows the name of device
15		of the corresponding devfreq object.
16
17What:		/sys/class/devfreq/.../governor
18Date:		September 2011
19Contact:	MyungJoo Ham <myungjoo.ham@samsung.com>
20Description:
21		The /sys/class/devfreq/.../governor show or set the name of the
22		governor used by the corresponding devfreq object.
23
24What:		/sys/class/devfreq/.../cur_freq
25Date:		September 2011
26Contact:	MyungJoo Ham <myungjoo.ham@samsung.com>
27Description:
28		The /sys/class/devfreq/.../cur_freq shows the current
29		frequency of the corresponding devfreq object. Same as
30		target_freq when get_cur_freq() is not implemented by
31		devfreq driver.
32
33What:		/sys/class/devfreq/.../target_freq
34Date:		September 2012
35Contact:	Rajagopal Venkat <rajagopal.venkat@linaro.org>
36Description:
37		The /sys/class/devfreq/.../target_freq shows the next governor
38		predicted target frequency of the corresponding devfreq object.
39
40What:		/sys/class/devfreq/.../polling_interval
41Date:		September 2011
42Contact:	MyungJoo Ham <myungjoo.ham@samsung.com>
43Description:
44		The /sys/class/devfreq/.../polling_interval shows and sets
45		the requested polling interval of the corresponding devfreq
46		object. The values are represented in ms. If the value is
47		less than 1 jiffy, it is considered to be 0, which means
48		no polling. This value is meaningless if the governor is
49		not polling; thus. If the governor is not using
50		devfreq-provided central polling
51		(/sys/class/devfreq/.../central_polling is 0), this value
52		may be useless.
53
54What:		/sys/class/devfreq/.../trans_stat
55Date:		October 2012
56Contact:	MyungJoo Ham <myungjoo.ham@samsung.com>
57Description:
58		This ABI shows or clears the statistics of devfreq behavior
59		on a specific device. It shows the time spent in each state
60		and the number of transitions between states.
61		In order to activate this ABI, the devfreq target device
62		driver should provide the list of available frequencies
63		with its profile. If need to reset the statistics of devfreq
64		behavior on a specific device, enter 0(zero) to 'trans_stat'
65		as following:
66			echo 0 > /sys/class/devfreq/.../trans_stat
67
68What:		/sys/class/devfreq/.../userspace/set_freq
69Date:		September 2011
70Contact:	MyungJoo Ham <myungjoo.ham@samsung.com>
71Description:
72		The /sys/class/devfreq/.../userspace/set_freq shows and
73		sets the requested frequency for the devfreq object if
74		userspace governor is in effect.
75
76What:		/sys/class/devfreq/.../available_frequencies
77Date:		October 2012
78Contact:	Nishanth Menon <nm@ti.com>
79Description:
80		The /sys/class/devfreq/.../available_frequencies shows
81		the available frequencies of the corresponding devfreq object.
82		This is a snapshot of available frequencies and not limited
83		by the min/max frequency restrictions.
84
85What:		/sys/class/devfreq/.../available_governors
86Date:		October 2012
87Contact:	Nishanth Menon <nm@ti.com>
88Description:
89		The /sys/class/devfreq/.../available_governors shows
90		currently available governors in the system.
91
92What:		/sys/class/devfreq/.../min_freq
93Date:		January 2013
94Contact:	MyungJoo Ham <myungjoo.ham@samsung.com>
95Description:
96		The /sys/class/devfreq/.../min_freq shows and stores
97		the minimum frequency requested by users. It is 0 if
98		the user does not care. min_freq overrides the
99		frequency requested by governors.
100
101What:		/sys/class/devfreq/.../max_freq
102Date:		January 2013
103Contact:	MyungJoo Ham <myungjoo.ham@samsung.com>
104Description:
105		The /sys/class/devfreq/.../max_freq shows and stores
106		the maximum frequency requested by users. It is 0 if
107		the user does not care. max_freq overrides the
108		frequency requested by governors and min_freq.
109		The max_freq overrides min_freq because max_freq may be
110		used to throttle devices to avoid overheating.
111
112What:		/sys/class/devfreq/.../timer
113Date:		July 2020
114Contact:	Chanwoo Choi <cw00.choi@samsung.com>
115Description:
116		This ABI shows and stores the kind of work timer by users.
117		This work timer is used by devfreq workqueue in order to
118		monitor the device status such as utilization. The user
119		can change the work timer on runtime according to their demand
120		as following:
121			echo deferrable > /sys/class/devfreq/.../timer
122			echo delayed > /sys/class/devfreq/.../timer
123