Merge branch 'master' of git://git.kernel.org/pub/scm/linux/kernel/git/klassert/ipsec
[linux-2.6-microblaze.git] / Documentation / ABI / testing / sysfs-class-devfreq
1 What:           /sys/class/devfreq/.../
2 Date:           September 2011
3 Contact:        MyungJoo Ham <myungjoo.ham@samsung.com>
4 Description:
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
10 What:           /sys/class/devfreq/.../name
11 Date:           November 2019
12 Contact:        Chanwoo Choi <cw00.choi@samsung.com>
13 Description:
14                 The /sys/class/devfreq/.../name shows the name of device
15                 of the corresponding devfreq object.
16
17 What:           /sys/class/devfreq/.../governor
18 Date:           September 2011
19 Contact:        MyungJoo Ham <myungjoo.ham@samsung.com>
20 Description:
21                 The /sys/class/devfreq/.../governor show or set the name of the
22                 governor used by the corresponding devfreq object.
23
24 What:           /sys/class/devfreq/.../cur_freq
25 Date:           September 2011
26 Contact:        MyungJoo Ham <myungjoo.ham@samsung.com>
27 Description:
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
33 What:           /sys/class/devfreq/.../target_freq
34 Date:           September 2012
35 Contact:        Rajagopal Venkat <rajagopal.venkat@linaro.org>
36 Description:
37                 The /sys/class/devfreq/.../target_freq shows the next governor
38                 predicted target frequency of the corresponding devfreq object.
39
40 What:           /sys/class/devfreq/.../trans_stat
41 Date:           October 2012
42 Contact:        MyungJoo Ham <myungjoo.ham@samsung.com>
43 Description:
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
55 What:           /sys/class/devfreq/.../available_frequencies
56 Date:           October 2012
57 Contact:        Nishanth Menon <nm@ti.com>
58 Description:
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
64 What:           /sys/class/devfreq/.../available_governors
65 Date:           October 2012
66 Contact:        Nishanth Menon <nm@ti.com>
67 Description:
68                 The /sys/class/devfreq/.../available_governors shows
69                 currently available governors in the system.
70
71 What:           /sys/class/devfreq/.../min_freq
72 Date:           January 2013
73 Contact:        MyungJoo Ham <myungjoo.ham@samsung.com>
74 Description:
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
80 What:           /sys/class/devfreq/.../max_freq
81 Date:           January 2013
82 Contact:        MyungJoo Ham <myungjoo.ham@samsung.com>
83 Description:
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
91 What:           /sys/class/devfreq/.../polling_interval
92 Date:           September 2011
93 Contact:        MyungJoo Ham <myungjoo.ham@samsung.com>
94 Description:
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.
101
102                 A list of governors that support the node:
103                 - simple_ondmenad
104                 - tegra_actmon
105
106 What:           /sys/class/devfreq/.../userspace/set_freq
107 Date:           September 2011
108 Contact:        MyungJoo Ham <myungjoo.ham@samsung.com>
109 Description:
110                 The /sys/class/devfreq/.../userspace/set_freq shows and
111                 sets the requested frequency for the devfreq object if
112                 userspace governor is in effect.
113
114                 A list of governors that support the node:
115                 - userspace
116
117 What:           /sys/class/devfreq/.../timer
118 Date:           July 2020
119 Contact:        Chanwoo Choi <cw00.choi@samsung.com>
120 Description:
121                 This ABI shows and stores the kind of work timer by users.
122                 This work timer is used by devfreq workqueue in order to
123                 monitor the device status such as utilization. The user
124                 can change the work timer on runtime according to their demand
125                 as following::
126
127                         echo deferrable > /sys/class/devfreq/.../timer
128                         echo delayed > /sys/class/devfreq/.../timer
129
130                 A list of governors that support the node:
131                 - simple_ondemand