1 What: /sys/class/devfreq/.../ 1 What: /sys/class/devfreq/.../
2 Date: September 2011 2 Date: September 2011
3 Contact: MyungJoo Ham <myungjoo.ham@sams 3 Contact: MyungJoo Ham <myungjoo.ham@samsung.com>
4 Description: 4 Description:
5 Provide a place in sysfs for t 5 Provide a place in sysfs for the devfreq objects.
6 This allows accessing various 6 This allows accessing various devfreq specific variables.
7 The name of devfreq object den 7 The name of devfreq object denoted as ... is same as the
8 name of device using devfreq. 8 name of device using devfreq.
9 9
10 What: /sys/class/devfreq/.../name 10 What: /sys/class/devfreq/.../name
11 Date: November 2019 11 Date: November 2019
12 Contact: Chanwoo Choi <cw00.choi@samsung 12 Contact: Chanwoo Choi <cw00.choi@samsung.com>
13 Description: 13 Description:
14 The /sys/class/devfreq/.../nam 14 The /sys/class/devfreq/.../name shows the name of device
15 of the corresponding devfreq o 15 of the corresponding devfreq object.
16 16
17 What: /sys/class/devfreq/.../governo 17 What: /sys/class/devfreq/.../governor
18 Date: September 2011 18 Date: September 2011
19 Contact: MyungJoo Ham <myungjoo.ham@sams 19 Contact: MyungJoo Ham <myungjoo.ham@samsung.com>
20 Description: 20 Description:
21 The /sys/class/devfreq/.../gov 21 The /sys/class/devfreq/.../governor show or set the name of the
22 governor used by the correspon 22 governor used by the corresponding devfreq object.
23 23
24 What: /sys/class/devfreq/.../cur_fre 24 What: /sys/class/devfreq/.../cur_freq
25 Date: September 2011 25 Date: September 2011
26 Contact: MyungJoo Ham <myungjoo.ham@sams 26 Contact: MyungJoo Ham <myungjoo.ham@samsung.com>
27 Description: 27 Description:
28 The /sys/class/devfreq/.../cur 28 The /sys/class/devfreq/.../cur_freq shows the current
29 frequency of the corresponding 29 frequency of the corresponding devfreq object. Same as
30 target_freq when get_cur_freq( 30 target_freq when get_cur_freq() is not implemented by
31 devfreq driver. 31 devfreq driver.
32 32
33 What: /sys/class/devfreq/.../target_ 33 What: /sys/class/devfreq/.../target_freq
34 Date: September 2012 34 Date: September 2012
35 Contact: Rajagopal Venkat <rajagopal.ven 35 Contact: Rajagopal Venkat <rajagopal.venkat@linaro.org>
36 Description: 36 Description:
37 The /sys/class/devfreq/.../tar 37 The /sys/class/devfreq/.../target_freq shows the next governor
38 predicted target frequency of 38 predicted target frequency of the corresponding devfreq object.
39 39
40 What: /sys/class/devfreq/.../trans_s 40 What: /sys/class/devfreq/.../trans_stat
41 Date: October 2012 41 Date: October 2012
42 Contact: MyungJoo Ham <myungjoo.ham@sams 42 Contact: MyungJoo Ham <myungjoo.ham@samsung.com>
43 Description: 43 Description:
44 This ABI shows or clears the s 44 This ABI shows or clears the statistics of devfreq behavior
45 on a specific device. It shows 45 on a specific device. It shows the time spent in each state
46 and the number of transitions 46 and the number of transitions between states.
47 In order to activate this ABI, 47 In order to activate this ABI, the devfreq target device
48 driver should provide the list 48 driver should provide the list of available frequencies
49 with its profile. If need to r 49 with its profile. If need to reset the statistics of devfreq
50 behavior on a specific device, 50 behavior on a specific device, enter 0(zero) to 'trans_stat'
51 as following:: 51 as following::
52 52
53 echo 0 > /sys/class/de 53 echo 0 > /sys/class/devfreq/.../trans_stat
54 54
55 If the transition table is big 55 If the transition table is bigger than PAGE_SIZE, reading
56 this will return an -EFBIG err 56 this will return an -EFBIG error.
57 57
58 What: /sys/class/devfreq/.../availab 58 What: /sys/class/devfreq/.../available_frequencies
59 Date: October 2012 59 Date: October 2012
60 Contact: Nishanth Menon <nm@ti.com> 60 Contact: Nishanth Menon <nm@ti.com>
61 Description: 61 Description:
62 The /sys/class/devfreq/.../ava 62 The /sys/class/devfreq/.../available_frequencies shows
63 the available frequencies of t 63 the available frequencies of the corresponding devfreq object.
64 This is a snapshot of availabl 64 This is a snapshot of available frequencies and not limited
65 by the min/max frequency restr 65 by the min/max frequency restrictions.
66 66
67 What: /sys/class/devfreq/.../availab 67 What: /sys/class/devfreq/.../available_governors
68 Date: October 2012 68 Date: October 2012
69 Contact: Nishanth Menon <nm@ti.com> 69 Contact: Nishanth Menon <nm@ti.com>
70 Description: 70 Description:
71 The /sys/class/devfreq/.../ava 71 The /sys/class/devfreq/.../available_governors shows
72 currently available governors 72 currently available governors in the system.
73 73
74 What: /sys/class/devfreq/.../min_fre 74 What: /sys/class/devfreq/.../min_freq
75 Date: January 2013 75 Date: January 2013
76 Contact: MyungJoo Ham <myungjoo.ham@sams 76 Contact: MyungJoo Ham <myungjoo.ham@samsung.com>
77 Description: 77 Description:
78 The /sys/class/devfreq/.../min 78 The /sys/class/devfreq/.../min_freq shows and stores
79 the minimum frequency requeste 79 the minimum frequency requested by users. It is 0 if
80 the user does not care. min_fr 80 the user does not care. min_freq overrides the
81 frequency requested by governo 81 frequency requested by governors.
82 82
83 What: /sys/class/devfreq/.../max_fre 83 What: /sys/class/devfreq/.../max_freq
84 Date: January 2013 84 Date: January 2013
85 Contact: MyungJoo Ham <myungjoo.ham@sams 85 Contact: MyungJoo Ham <myungjoo.ham@samsung.com>
86 Description: 86 Description:
87 The /sys/class/devfreq/.../max 87 The /sys/class/devfreq/.../max_freq shows and stores
88 the maximum frequency requeste 88 the maximum frequency requested by users. It is 0 if
89 the user does not care. max_fr 89 the user does not care. max_freq overrides the
90 frequency requested by governo 90 frequency requested by governors and min_freq.
91 The max_freq overrides min_fre 91 The max_freq overrides min_freq because max_freq may be
92 used to throttle devices to av 92 used to throttle devices to avoid overheating.
93 93
94 What: /sys/class/devfreq/.../polling 94 What: /sys/class/devfreq/.../polling_interval
95 Date: September 2011 95 Date: September 2011
96 Contact: MyungJoo Ham <myungjoo.ham@sams 96 Contact: MyungJoo Ham <myungjoo.ham@samsung.com>
97 Description: 97 Description:
98 The /sys/class/devfreq/.../pol 98 The /sys/class/devfreq/.../polling_interval shows and sets
99 the requested polling interval 99 the requested polling interval of the corresponding devfreq
100 object. The values are represe 100 object. The values are represented in ms. If the value is
101 less than 1 jiffy, it is consi 101 less than 1 jiffy, it is considered to be 0, which means
102 no polling. This value is mean 102 no polling. This value is meaningless if the governor is
103 not polling. 103 not polling.
104 104
105 A list of governors that suppo 105 A list of governors that support the node:
106 - simple_ondmenad 106 - simple_ondmenad
107 - tegra_actmon 107 - tegra_actmon
108 108
109 What: /sys/class/devfreq/.../userspa 109 What: /sys/class/devfreq/.../userspace/set_freq
110 Date: September 2011 110 Date: September 2011
111 Contact: MyungJoo Ham <myungjoo.ham@sams 111 Contact: MyungJoo Ham <myungjoo.ham@samsung.com>
112 Description: 112 Description:
113 The /sys/class/devfreq/.../use 113 The /sys/class/devfreq/.../userspace/set_freq shows and
114 sets the requested frequency f 114 sets the requested frequency for the devfreq object if
115 userspace governor is in effec 115 userspace governor is in effect.
116 116
117 A list of governors that suppo 117 A list of governors that support the node:
118 - userspace 118 - userspace
119 119
120 What: /sys/class/devfreq/.../timer 120 What: /sys/class/devfreq/.../timer
121 Date: July 2020 121 Date: July 2020
122 Contact: Chanwoo Choi <cw00.choi@samsung 122 Contact: Chanwoo Choi <cw00.choi@samsung.com>
123 Description: 123 Description:
124 This ABI shows and stores the 124 This ABI shows and stores the kind of work timer by users.
125 This work timer is used by dev 125 This work timer is used by devfreq workqueue in order to
126 monitor the device status such 126 monitor the device status such as utilization. The user
127 can change the work timer on r 127 can change the work timer on runtime according to their demand
128 as following:: 128 as following::
129 129
130 echo deferrable > /sys 130 echo deferrable > /sys/class/devfreq/.../timer
131 echo delayed > /sys/cl 131 echo delayed > /sys/class/devfreq/.../timer
132 132
133 A list of governors that suppo 133 A list of governors that support the node:
134 - simple_ondemand 134 - simple_ondemand
Linux® is a registered trademark of Linus Torvalds in the United States and other countries.
TOMOYO® is a registered trademark of NTT DATA CORPORATION.