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 If the transition table is bigger than PAGE_SIZE, reading 56 this will return an -EFBIG error. 57 58 What: /sys/class/devfreq/.../available_frequencies 59 Date: October 2012 60 Contact: Nishanth Menon <nm@ti.com> 61 Description: 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 67 What: /sys/class/devfreq/.../available_governors 68 Date: October 2012 69 Contact: Nishanth Menon <nm@ti.com> 70 Description: 71 The /sys/class/devfreq/.../available_governors shows 72 currently available governors in the system. 73 74 What: /sys/class/devfreq/.../min_freq 75 Date: January 2013 76 Contact: MyungJoo Ham <myungjoo.ham@samsung.com> 77 Description: 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 83 What: /sys/class/devfreq/.../max_freq 84 Date: January 2013 85 Contact: MyungJoo Ham <myungjoo.ham@samsung.com> 86 Description: 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 94 What: /sys/class/devfreq/.../polling_interval 95 Date: September 2011 96 Contact: MyungJoo Ham <myungjoo.ham@samsung.com> 97 Description: 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 108 109 What: /sys/class/devfreq/.../userspace/set_freq 110 Date: September 2011 111 Contact: MyungJoo Ham <myungjoo.ham@samsung.com> 112 Description: 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 119 120 What: /sys/class/devfreq/.../timer 121 Date: July 2020 122 Contact: Chanwoo Choi <cw00.choi@samsung.com> 123 Description: 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
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