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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
55 If the transition table is bigger than PAGE_SIZE, reading
56 this will return an -EFBIG error.
57
58What: /sys/class/devfreq/.../available_frequencies
59Date: October 2012
60Contact: Nishanth Menon <nm@ti.com>
61Description:
62 The /sys/class/devfreq/.../available_frequencies shows
63 the available frequencies of the corresponding devfreq object.
64 This is a snapshot of available frequencies and not limited
65 by the min/max frequency restrictions.
66
67What: /sys/class/devfreq/.../available_governors
68Date: October 2012
69Contact: Nishanth Menon <nm@ti.com>
70Description:
71 The /sys/class/devfreq/.../available_governors shows
72 currently available governors in the system.
73
74What: /sys/class/devfreq/.../min_freq
75Date: January 2013
76Contact: MyungJoo Ham <myungjoo.ham@samsung.com>
77Description:
78 The /sys/class/devfreq/.../min_freq shows and stores
79 the minimum frequency requested by users. It is 0 if
80 the user does not care. min_freq overrides the
81 frequency requested by governors.
82
83What: /sys/class/devfreq/.../max_freq
84Date: January 2013
85Contact: MyungJoo Ham <myungjoo.ham@samsung.com>
86Description:
87 The /sys/class/devfreq/.../max_freq shows and stores
88 the maximum frequency requested by users. It is 0 if
89 the user does not care. max_freq overrides the
90 frequency requested by governors and min_freq.
91 The max_freq overrides min_freq because max_freq may be
92 used to throttle devices to avoid overheating.
93
94What: /sys/class/devfreq/.../polling_interval
95Date: September 2011
96Contact: MyungJoo Ham <myungjoo.ham@samsung.com>
97Description:
98 The /sys/class/devfreq/.../polling_interval shows and sets
99 the requested polling interval of the corresponding devfreq
100 object. The values are represented in ms. If the value is
101 less than 1 jiffy, it is considered to be 0, which means
102 no polling. This value is meaningless if the governor is
103 not polling.
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
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