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/.../trans_stat
41Date:		October 2012
42Contact:	MyungJoo Ham <myungjoo.ham@samsung.com>
43Description:
44		This ABI shows or clears the statistics of devfreq behavior
45		on a specific device. It shows the time spent in each state
46		and the number of transitions between states.
47		In order to activate this ABI, the devfreq target device
48		driver should provide the list of available frequencies
49		with its profile. If need to reset the statistics of devfreq
50		behavior on a specific device, enter 0(zero) to 'trans_stat'
51		as following::
52
53			echo 0 > /sys/class/devfreq/.../trans_stat
54
55What:		/sys/class/devfreq/.../available_frequencies
56Date:		October 2012
57Contact:	Nishanth Menon <nm@ti.com>
58Description:
59		The /sys/class/devfreq/.../available_frequencies shows
60		the available frequencies of the corresponding devfreq object.
61		This is a snapshot of available frequencies and not limited
62		by the min/max frequency restrictions.
63
64What:		/sys/class/devfreq/.../available_governors
65Date:		October 2012
66Contact:	Nishanth Menon <nm@ti.com>
67Description:
68		The /sys/class/devfreq/.../available_governors shows
69		currently available governors in the system.
70
71What:		/sys/class/devfreq/.../min_freq
72Date:		January 2013
73Contact:	MyungJoo Ham <myungjoo.ham@samsung.com>
74Description:
75		The /sys/class/devfreq/.../min_freq shows and stores
76		the minimum frequency requested by users. It is 0 if
77		the user does not care. min_freq overrides the
78		frequency requested by governors.
79
80What:		/sys/class/devfreq/.../max_freq
81Date:		January 2013
82Contact:	MyungJoo Ham <myungjoo.ham@samsung.com>
83Description:
84		The /sys/class/devfreq/.../max_freq shows and stores
85		the maximum frequency requested by users. It is 0 if
86		the user does not care. max_freq overrides the
87		frequency requested by governors and min_freq.
88		The max_freq overrides min_freq because max_freq may be
89		used to throttle devices to avoid overheating.
90
91What:		/sys/class/devfreq/.../polling_interval
92Date:		September 2011
93Contact:	MyungJoo Ham <myungjoo.ham@samsung.com>
94Description:
95		The /sys/class/devfreq/.../polling_interval shows and sets
96		the requested polling interval of the corresponding devfreq
97		object. The values are represented in ms. If the value is
98		less than 1 jiffy, it is considered to be 0, which means
99		no polling. This value is meaningless if the governor is
100		not polling; thus. If the governor is not using
101		devfreq-provided central polling
102		(/sys/class/devfreq/.../central_polling is 0), this value
103		may be useless.
104
105		A list of governors that support the node:
106		- simple_ondmenad
107		- tegra_actmon
108
109What:		/sys/class/devfreq/.../userspace/set_freq
110Date:		September 2011
111Contact:	MyungJoo Ham <myungjoo.ham@samsung.com>
112Description:
113		The /sys/class/devfreq/.../userspace/set_freq shows and
114		sets the requested frequency for the devfreq object if
115		userspace governor is in effect.
116
117		A list of governors that support the node:
118		- userspace
119
120What:		/sys/class/devfreq/.../timer
121Date:		July 2020
122Contact:	Chanwoo Choi <cw00.choi@samsung.com>
123Description:
124		This ABI shows and stores the kind of work timer by users.
125		This work timer is used by devfreq workqueue in order to
126		monitor the device status such as utilization. The user
127		can change the work timer on runtime according to their demand
128		as following::
129
130			echo deferrable > /sys/class/devfreq/.../timer
131			echo delayed > /sys/class/devfreq/.../timer
132
133		A list of governors that support the node:
134		- simple_ondemand
135