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 67 echo 0 > /sys/class/devfreq/.../trans_stat 68 69 If the transition table is bigger than PAGE_SIZE, reading 70 this will return an -EFBIG error. 71 72What: /sys/class/devfreq/.../userspace/set_freq 73Date: September 2011 74Contact: MyungJoo Ham <myungjoo.ham@samsung.com> 75Description: 76 The /sys/class/devfreq/.../userspace/set_freq shows and 77 sets the requested frequency for the devfreq object if 78 userspace governor is in effect. 79 80What: /sys/class/devfreq/.../available_frequencies 81Date: October 2012 82Contact: Nishanth Menon <nm@ti.com> 83Description: 84 The /sys/class/devfreq/.../available_frequencies shows 85 the available frequencies of the corresponding devfreq object. 86 This is a snapshot of available frequencies and not limited 87 by the min/max frequency restrictions. 88 89What: /sys/class/devfreq/.../available_governors 90Date: October 2012 91Contact: Nishanth Menon <nm@ti.com> 92Description: 93 The /sys/class/devfreq/.../available_governors shows 94 currently available governors in the system. 95 96What: /sys/class/devfreq/.../min_freq 97Date: January 2013 98Contact: MyungJoo Ham <myungjoo.ham@samsung.com> 99Description: 100 The /sys/class/devfreq/.../min_freq shows and stores 101 the minimum frequency requested by users. It is 0 if 102 the user does not care. min_freq overrides the 103 frequency requested by governors. 104 105What: /sys/class/devfreq/.../max_freq 106Date: January 2013 107Contact: MyungJoo Ham <myungjoo.ham@samsung.com> 108Description: 109 The /sys/class/devfreq/.../max_freq shows and stores 110 the maximum frequency requested by users. It is 0 if 111 the user does not care. max_freq overrides the 112 frequency requested by governors and min_freq. 113 The max_freq overrides min_freq because max_freq may be 114 used to throttle devices to avoid overheating. 115 116What: /sys/class/devfreq/.../timer 117Date: July 2020 118Contact: Chanwoo Choi <cw00.choi@samsung.com> 119Description: 120 This ABI shows and stores the kind of work timer by users. 121 This work timer is used by devfreq workqueue in order to 122 monitor the device status such as utilization. The user 123 can change the work timer on runtime according to their demand 124 as following:: 125 126 echo deferrable > /sys/class/devfreq/.../timer 127 echo delayed > /sys/class/devfreq/.../timer 128