0001 What: /sys/class/devfreq/.../
0002 Date: September 2011
0003 Contact: MyungJoo Ham <myungjoo.ham@samsung.com>
0004 Description:
0005 Provide a place in sysfs for the devfreq objects.
0006 This allows accessing various devfreq specific variables.
0007 The name of devfreq object denoted as ... is same as the
0008 name of device using devfreq.
0009
0010 What: /sys/class/devfreq/.../name
0011 Date: November 2019
0012 Contact: Chanwoo Choi <cw00.choi@samsung.com>
0013 Description:
0014 The /sys/class/devfreq/.../name shows the name of device
0015 of the corresponding devfreq object.
0016
0017 What: /sys/class/devfreq/.../governor
0018 Date: September 2011
0019 Contact: MyungJoo Ham <myungjoo.ham@samsung.com>
0020 Description:
0021 The /sys/class/devfreq/.../governor show or set the name of the
0022 governor used by the corresponding devfreq object.
0023
0024 What: /sys/class/devfreq/.../cur_freq
0025 Date: September 2011
0026 Contact: MyungJoo Ham <myungjoo.ham@samsung.com>
0027 Description:
0028 The /sys/class/devfreq/.../cur_freq shows the current
0029 frequency of the corresponding devfreq object. Same as
0030 target_freq when get_cur_freq() is not implemented by
0031 devfreq driver.
0032
0033 What: /sys/class/devfreq/.../target_freq
0034 Date: September 2012
0035 Contact: Rajagopal Venkat <rajagopal.venkat@linaro.org>
0036 Description:
0037 The /sys/class/devfreq/.../target_freq shows the next governor
0038 predicted target frequency of the corresponding devfreq object.
0039
0040 What: /sys/class/devfreq/.../trans_stat
0041 Date: October 2012
0042 Contact: MyungJoo Ham <myungjoo.ham@samsung.com>
0043 Description:
0044 This ABI shows or clears the statistics of devfreq behavior
0045 on a specific device. It shows the time spent in each state
0046 and the number of transitions between states.
0047 In order to activate this ABI, the devfreq target device
0048 driver should provide the list of available frequencies
0049 with its profile. If need to reset the statistics of devfreq
0050 behavior on a specific device, enter 0(zero) to 'trans_stat'
0051 as following::
0052
0053 echo 0 > /sys/class/devfreq/.../trans_stat
0054
0055 What: /sys/class/devfreq/.../available_frequencies
0056 Date: October 2012
0057 Contact: Nishanth Menon <nm@ti.com>
0058 Description:
0059 The /sys/class/devfreq/.../available_frequencies shows
0060 the available frequencies of the corresponding devfreq object.
0061 This is a snapshot of available frequencies and not limited
0062 by the min/max frequency restrictions.
0063
0064 What: /sys/class/devfreq/.../available_governors
0065 Date: October 2012
0066 Contact: Nishanth Menon <nm@ti.com>
0067 Description:
0068 The /sys/class/devfreq/.../available_governors shows
0069 currently available governors in the system.
0070
0071 What: /sys/class/devfreq/.../min_freq
0072 Date: January 2013
0073 Contact: MyungJoo Ham <myungjoo.ham@samsung.com>
0074 Description:
0075 The /sys/class/devfreq/.../min_freq shows and stores
0076 the minimum frequency requested by users. It is 0 if
0077 the user does not care. min_freq overrides the
0078 frequency requested by governors.
0079
0080 What: /sys/class/devfreq/.../max_freq
0081 Date: January 2013
0082 Contact: MyungJoo Ham <myungjoo.ham@samsung.com>
0083 Description:
0084 The /sys/class/devfreq/.../max_freq shows and stores
0085 the maximum frequency requested by users. It is 0 if
0086 the user does not care. max_freq overrides the
0087 frequency requested by governors and min_freq.
0088 The max_freq overrides min_freq because max_freq may be
0089 used to throttle devices to avoid overheating.
0090
0091 What: /sys/class/devfreq/.../polling_interval
0092 Date: September 2011
0093 Contact: MyungJoo Ham <myungjoo.ham@samsung.com>
0094 Description:
0095 The /sys/class/devfreq/.../polling_interval shows and sets
0096 the requested polling interval of the corresponding devfreq
0097 object. The values are represented in ms. If the value is
0098 less than 1 jiffy, it is considered to be 0, which means
0099 no polling. This value is meaningless if the governor is
0100 not polling.
0101
0102 A list of governors that support the node:
0103 - simple_ondmenad
0104 - tegra_actmon
0105
0106 What: /sys/class/devfreq/.../userspace/set_freq
0107 Date: September 2011
0108 Contact: MyungJoo Ham <myungjoo.ham@samsung.com>
0109 Description:
0110 The /sys/class/devfreq/.../userspace/set_freq shows and
0111 sets the requested frequency for the devfreq object if
0112 userspace governor is in effect.
0113
0114 A list of governors that support the node:
0115 - userspace
0116
0117 What: /sys/class/devfreq/.../timer
0118 Date: July 2020
0119 Contact: Chanwoo Choi <cw00.choi@samsung.com>
0120 Description:
0121 This ABI shows and stores the kind of work timer by users.
0122 This work timer is used by devfreq workqueue in order to
0123 monitor the device status such as utilization. The user
0124 can change the work timer on runtime according to their demand
0125 as following::
0126
0127 echo deferrable > /sys/class/devfreq/.../timer
0128 echo delayed > /sys/class/devfreq/.../timer
0129
0130 A list of governors that support the node:
0131 - simple_ondemand
