What: /sys/class/devfreq/.../
Date: September 2011
Contact: MyungJoo Ham <[email protected]>
Description:
Provide a place in sysfs for the devfreq objects.
This allows accessing various devfreq specific variables.
The name of devfreq object denoted as ... is same as the
name of device using devfreq.
What: /sys/class/devfreq/.../name
Date: November 2019
Contact: Chanwoo Choi <[email protected]>
Description:
The /sys/class/devfreq/.../name shows the name of device
of the corresponding devfreq object.
What: /sys/class/devfreq/.../governor
Date: September 2011
Contact: MyungJoo Ham <[email protected]>
Description:
The /sys/class/devfreq/.../governor show or set the name of the
governor used by the corresponding devfreq object.
What: /sys/class/devfreq/.../cur_freq
Date: September 2011
Contact: MyungJoo Ham <[email protected]>
Description:
The /sys/class/devfreq/.../cur_freq shows the current
frequency of the corresponding devfreq object. Same as
target_freq when get_cur_freq() is not implemented by
devfreq driver.
What: /sys/class/devfreq/.../target_freq
Date: September 2012
Contact: Rajagopal Venkat <[email protected]>
Description:
The /sys/class/devfreq/.../target_freq shows the next governor
predicted target frequency of the corresponding devfreq object.
What: /sys/class/devfreq/.../trans_stat
Date: October 2012
Contact: MyungJoo Ham <[email protected]>
Description:
This ABI shows or clears the statistics of devfreq behavior
on a specific device. It shows the time spent in each state
and the number of transitions between states.
In order to activate this ABI, the devfreq target device
driver should provide the list of available frequencies
with its profile. If need to reset the statistics of devfreq
behavior on a specific device, enter 0(zero) to 'trans_stat'
as following::
echo 0 > /sys/class/devfreq/.../trans_stat
If the transition table is bigger than PAGE_SIZE, reading
this will return an -EFBIG error.
What: /sys/class/devfreq/.../available_frequencies
Date: October 2012
Contact: Nishanth Menon <[email protected]>
Description:
The /sys/class/devfreq/.../available_frequencies shows
the available frequencies of the corresponding devfreq object.
This is a snapshot of available frequencies and not limited
by the min/max frequency restrictions.
What: /sys/class/devfreq/.../available_governors
Date: October 2012
Contact: Nishanth Menon <[email protected]>
Description:
The /sys/class/devfreq/.../available_governors shows
currently available governors in the system.
What: /sys/class/devfreq/.../min_freq
Date: January 2013
Contact: MyungJoo Ham <[email protected]>
Description:
The /sys/class/devfreq/.../min_freq shows and stores
the minimum frequency requested by users. It is 0 if
the user does not care. min_freq overrides the
frequency requested by governors.
What: /sys/class/devfreq/.../max_freq
Date: January 2013
Contact: MyungJoo Ham <[email protected]>
Description:
The /sys/class/devfreq/.../max_freq shows and stores
the maximum frequency requested by users. It is 0 if
the user does not care. max_freq overrides the
frequency requested by governors and min_freq.
The max_freq overrides min_freq because max_freq may be
used to throttle devices to avoid overheating.
What: /sys/class/devfreq/.../polling_interval
Date: September 2011
Contact: MyungJoo Ham <[email protected]>
Description:
The /sys/class/devfreq/.../polling_interval shows and sets
the requested polling interval of the corresponding devfreq
object. The values are represented in ms. If the value is
less than 1 jiffy, it is considered to be 0, which means
no polling. This value is meaningless if the governor is
not polling.
A list of governors that support the node:
- simple_ondmenad
- tegra_actmon
What: /sys/class/devfreq/.../userspace/set_freq
Date: September 2011
Contact: MyungJoo Ham <[email protected]>
Description:
The /sys/class/devfreq/.../userspace/set_freq shows and
sets the requested frequency for the devfreq object if
userspace governor is in effect.
A list of governors that support the node:
- userspace
What: /sys/class/devfreq/.../timer
Date: July 2020
Contact: Chanwoo Choi <[email protected]>
Description:
This ABI shows and stores the kind of work timer by users.
This work timer is used by devfreq workqueue in order to
monitor the device status such as utilization. The user
can change the work timer on runtime according to their demand
as following::
echo deferrable > /sys/class/devfreq/.../timer
echo delayed > /sys/class/devfreq/.../timer
A list of governors that support the node:
- simple_ondemand
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