Documentation/ABI/testing/sysfs-class-devfreq

Source file repositories/reference/linux-study-clean/Documentation/ABI/testing/sysfs-class-devfreq

File Facts

System
Linux kernel
Corpus path
Documentation/ABI/testing/sysfs-class-devfreq
Extension
[no extension]
Size
5126 bytes
Lines
144
Domain
Support Tooling And Documentation
Bucket
Documentation
Inferred role
Support Tooling And Documentation: Documentation
Status
atlas-only

Why This File Exists

Repository support layer: documentation, build tooling, samples, user-space helper tools, generated initramfs support, licenses, and validation utilities.

Dependency Surface

Detected Declarations

Annotated Snippet

What:		/sys/class/devfreq/.../
Date:		September 2011
Contact:	MyungJoo Ham <myungjoo.ham@samsung.com>
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 <cw00.choi@samsung.com>
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 <myungjoo.ham@samsung.com>
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 <myungjoo.ham@samsung.com>
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 <rajagopal.venkat@linaro.org>
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 <myungjoo.ham@samsung.com>
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 <nm@ti.com>
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 <nm@ti.com>
Description:

Annotation

Implementation Notes