xref: /openbmc/linux/Documentation/ABI/testing/sysfs-class-powercap (revision 151f4e2b)

What:		/sys/class/powercap/
Date:		September 2013
KernelVersion:	3.13
Contact:	linux-pm@vger.kernel.org
Description:
		The powercap/ class sub directory belongs to the power cap
		subsystem. Refer to
		Documentation/power/powercap/powercap.rst for details.

What:		/sys/class/powercap/<control type>
Date:		September 2013
KernelVersion:	3.13
Contact:	linux-pm@vger.kernel.org
Description:
		A <control type> is a unique name under /sys/class/powercap.
		Here <control type> determines how the power is going to be
		controlled. A <control type> can contain multiple power zones.

What:		/sys/class/powercap/<control type>/enabled
Date:		September 2013
KernelVersion:	3.13
Contact:	linux-pm@vger.kernel.org
Description:
		This allows to enable/disable power capping for a "control type".
		This status affects every power zone using this "control_type.

What:		/sys/class/powercap/<control type>/<power zone>
Date:		September 2013
KernelVersion:	3.13
Contact:	linux-pm@vger.kernel.org
Description:
		A power zone is a single or a collection of devices, which can
		be independently monitored and controlled. A power zone sysfs
		entry is qualified with the name of the <control type>.
		E.g. intel-rapl:0:1:1.

What:		/sys/class/powercap/<control type>/<power zone>/<child power zone>
Date:		September 2013
KernelVersion:	3.13
Contact:	linux-pm@vger.kernel.org
Description:
		Power zones may be organized in a hierarchy in which child
		power zones provide monitoring and control for a subset of
		devices under the parent. For example, if there is a parent
		power zone for a whole CPU package, each CPU core in it can
		be a child power zone.

What:		/sys/class/powercap/.../<power zone>/name
Date:		September 2013
KernelVersion:	3.13
Contact:	linux-pm@vger.kernel.org
Description:
		Specifies the name of this power zone.

What:		/sys/class/powercap/.../<power zone>/energy_uj
Date:		September 2013
KernelVersion:	3.13
Contact:	linux-pm@vger.kernel.org
Description:
		Current energy counter in micro-joules. Write "0" to reset.
		If the counter can not be reset, then this attribute is
		read-only.

What:		/sys/class/powercap/.../<power zone>/max_energy_range_uj
Date:		September 2013
KernelVersion:	3.13
Contact:	linux-pm@vger.kernel.org
Description:
		Range of the above energy counter in micro-joules.


What:		/sys/class/powercap/.../<power zone>/power_uw
Date:		September 2013
KernelVersion:	3.13
Contact:	linux-pm@vger.kernel.org
Description:
		Current power in micro-watts.

What:		/sys/class/powercap/.../<power zone>/max_power_range_uw
Date:		September 2013
KernelVersion:	3.13
Contact:	linux-pm@vger.kernel.org
Description:
		Range of the above power value in micro-watts.

What:		/sys/class/powercap/.../<power zone>/constraint_X_name
Date:		September 2013
KernelVersion:	3.13
Contact:	linux-pm@vger.kernel.org
Description:
		Each power zone can define one or more constraints. Each
		constraint can have an optional name. Here "X" can have values
		from 0 to max integer.

What:		/sys/class/powercap/.../<power zone>/constraint_X_power_limit_uw
Date:		September 2013
KernelVersion:	3.13
Contact:	linux-pm@vger.kernel.org
Description:
		Power limit in micro-watts should be applicable for
		the time window specified by "constraint_X_time_window_us".
		Here "X" can have values from 0 to max integer.

What:		/sys/class/powercap/.../<power zone>/constraint_X_time_window_us
Date:		September 2013
KernelVersion:	3.13
Contact:	linux-pm@vger.kernel.org
Description:
		Time window in micro seconds. This is used along with
		constraint_X_power_limit_uw to define a power constraint.
		Here "X" can have values from 0 to max integer.


What:		/sys/class/powercap/<control type>/.../constraint_X_max_power_uw
Date:		September 2013
KernelVersion:	3.13
Contact:	linux-pm@vger.kernel.org
Description:
		Maximum allowed power in micro watts for this constraint.
		Here "X" can have values from 0 to max integer.

What:		/sys/class/powercap/<control type>/.../constraint_X_min_power_uw
Date:		September 2013
KernelVersion:	3.13
Contact:	linux-pm@vger.kernel.org
Description:
		Minimum allowed power in micro watts for this constraint.
		Here "X" can have values from 0 to max integer.

What:		/sys/class/powercap/.../<power zone>/constraint_X_max_time_window_us
Date:		September 2013
KernelVersion:	3.13
Contact:	linux-pm@vger.kernel.org
Description:
		Maximum allowed time window in micro seconds for this
		constraint. Here "X" can have values from 0 to max integer.

What:		/sys/class/powercap/.../<power zone>/constraint_X_min_time_window_us
Date:		September 2013
KernelVersion:	3.13
Contact:	linux-pm@vger.kernel.org
Description:
		Minimum allowed time window in micro seconds for this
		constraint. Here "X" can have values from 0 to max integer.

What:		/sys/class/powercap/.../<power zone>/enabled
Date:		September 2013
KernelVersion:	3.13
Contact:	linux-pm@vger.kernel.org
Description:
		This allows to enable/disable power capping at power zone level.
		This applies to current power zone and its children.