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