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linux/Documentation/ABI/testing/sysfs-class-devfreq

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PM / devfreq: Add common sysfs interfaces Device specific sysfs interface /sys/devices/.../power/devfreq_* - governor R: name of governor - cur_freq R: current frequency - polling_interval R: polling interval in ms given with devfreq profile W: update polling interval. - central_polling R: 1 if polling is managed by devfreq framework Signed-off-by: MyungJoo Ham <myungjoo.ham@samsung.com> Signed-off-by: Kyungmin Park <kyungmin.park@samsung.com> Reviewed-by: Mike Turquette <mturquette@ti.com> Acked-by: Kevin Hilman <khilman@ti.com> Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl> -- Documentation/ABI/testing/sysfs-class-devfreq | 44 ++++++++++++++++ drivers/devfreq/devfreq.c | 69 ++++++++++++++++++++++++++ 2 files changed, 113 insertions(+) create mode 100644 Documentation/ABI/testing/sysfs-class-devfreq
2011-10-01 22:19:28 +00:00
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/.../governor
Date: September 2011
Contact: MyungJoo Ham <myungjoo.ham@samsung.com>
Description:
PM / devfreq: allow sysfs governor node to switch governor This allows us to select governor runtime from the default configuration without having to rebuild kernel or the devfreq driver using the sysfs node: /sys/class/devfreq/.../governor cat of the governor will return valid governor and an echo 'governor_name'>governor will switch governor Cc: Rajagopal Venkat <rajagopal.venkat@linaro.org> Cc: MyungJoo Ham <myungjoo.ham@samsung.com> Cc: Kyungmin Park <kyungmin.park@samsung.com> Cc: "Rafael J. Wysocki" <rjw@sisk.pl> Cc: Kevin Hilman <khilman@ti.com> Cc: linux-pm@vger.kernel.org Cc: linux-kernel@vger.kernel.org Signed-off-by: Nishanth Menon <nm@ti.com> Acked-by: MyungJoo Ham <myungjoo.ham@samsung.com> Signed-off-by: MyungJoo Ham <myungjoo.ham@samsung.com>
2012-10-29 20:01:47 +00:00
The /sys/class/devfreq/.../governor show or set the name of the
PM / devfreq: Add common sysfs interfaces Device specific sysfs interface /sys/devices/.../power/devfreq_* - governor R: name of governor - cur_freq R: current frequency - polling_interval R: polling interval in ms given with devfreq profile W: update polling interval. - central_polling R: 1 if polling is managed by devfreq framework Signed-off-by: MyungJoo Ham <myungjoo.ham@samsung.com> Signed-off-by: Kyungmin Park <kyungmin.park@samsung.com> Reviewed-by: Mike Turquette <mturquette@ti.com> Acked-by: Kevin Hilman <khilman@ti.com> Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl> -- Documentation/ABI/testing/sysfs-class-devfreq | 44 ++++++++++++++++ drivers/devfreq/devfreq.c | 69 ++++++++++++++++++++++++++ 2 files changed, 113 insertions(+) create mode 100644 Documentation/ABI/testing/sysfs-class-devfreq
2011-10-01 22:19:28 +00:00
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
PM / devfreq: Add current freq callback in device profile Devfreq returns governor predicted frequency as current frequency via sysfs interface. But device may not support all frequencies that governor predicts. So add a callback in device profile to get current freq from driver. Also add a new sysfs node to expose governor predicted next target frequency. Signed-off-by: Rajagopal Venkat <rajagopal.venkat@linaro.org> Acked-by: MyungJoo Ham <myungjoo.ham@samsung.com> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2012-10-25 23:50:26 +00:00
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.
PM / devfreq: Add common sysfs interfaces Device specific sysfs interface /sys/devices/.../power/devfreq_* - governor R: name of governor - cur_freq R: current frequency - polling_interval R: polling interval in ms given with devfreq profile W: update polling interval. - central_polling R: 1 if polling is managed by devfreq framework Signed-off-by: MyungJoo Ham <myungjoo.ham@samsung.com> Signed-off-by: Kyungmin Park <kyungmin.park@samsung.com> Reviewed-by: Mike Turquette <mturquette@ti.com> Acked-by: Kevin Hilman <khilman@ti.com> Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl> -- Documentation/ABI/testing/sysfs-class-devfreq | 44 ++++++++++++++++ drivers/devfreq/devfreq.c | 69 ++++++++++++++++++++++++++ 2 files changed, 113 insertions(+) create mode 100644 Documentation/ABI/testing/sysfs-class-devfreq
2011-10-01 22:19:28 +00:00
What: /sys/class/devfreq/.../polling_interval
Date: September 2011
Contact: MyungJoo Ham <myungjoo.ham@samsung.com>
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; thus. If the governor is not using
devfreq-provided central polling
(/sys/class/devfreq/.../central_polling is 0), this value
may be useless.
PM / devfreq: Add basic governors Four cpufreq-like governors are provided as examples. powersave: use the lowest frequency possible. The user (device) should set the polling_ms as 0 because polling is useless for this governor. performance: use the highest freqeuncy possible. The user (device) should set the polling_ms as 0 because polling is useless for this governor. userspace: use the user specified frequency stored at devfreq.user_set_freq. With sysfs support in the following patch, a user may set the value with the sysfs interface. simple_ondemand: simplified version of cpufreq's ondemand governor. When a user updates OPP entries (enable/disable/add), OPP framework automatically notifies devfreq to update operating frequency accordingly. Thus, devfreq users (device drivers) do not need to update devfreq manually with OPP entry updates or set polling_ms for powersave , performance, userspace, or any other "static" governors. Note that these are given only as basic examples for governors and any devices with devfreq may implement their own governors with the drivers and use them. Signed-off-by: MyungJoo Ham <myungjoo.ham@samsung.com> Signed-off-by: Kyungmin Park <kyungmin.park@samsung.com> Reviewed-by: Mike Turquette <mturquette@ti.com> Acked-by: Kevin Hilman <khilman@ti.com> Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
2011-10-01 22:19:34 +00:00
PM / devfreq: Add sysfs node for representing frequency transition information. This patch adds sysfs node which can be used to get information of frequency transition. It represents transition table which contains total number of transition of each freqeuncy state and time spent. It is inspired CPUFREQ's status driver. Signed-off-by: Jonghwa Lee <jonghwa3.lee@samsung.com> [Added Documentation/ABI entry, updated kernel-doc, and resolved merge conflict] Signed-off-by: MyungJoo Ham <myungjoo.ham@samsung.com>
2012-08-23 11:00:46 +00:00
What: /sys/class/devfreq/.../trans_stat
Date: October 2012
Contact: MyungJoo Ham <myungjoo.ham@samsung.com>
Descrtiption:
This ABI shows 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.
PM / devfreq: Add basic governors Four cpufreq-like governors are provided as examples. powersave: use the lowest frequency possible. The user (device) should set the polling_ms as 0 because polling is useless for this governor. performance: use the highest freqeuncy possible. The user (device) should set the polling_ms as 0 because polling is useless for this governor. userspace: use the user specified frequency stored at devfreq.user_set_freq. With sysfs support in the following patch, a user may set the value with the sysfs interface. simple_ondemand: simplified version of cpufreq's ondemand governor. When a user updates OPP entries (enable/disable/add), OPP framework automatically notifies devfreq to update operating frequency accordingly. Thus, devfreq users (device drivers) do not need to update devfreq manually with OPP entry updates or set polling_ms for powersave , performance, userspace, or any other "static" governors. Note that these are given only as basic examples for governors and any devices with devfreq may implement their own governors with the drivers and use them. Signed-off-by: MyungJoo Ham <myungjoo.ham@samsung.com> Signed-off-by: Kyungmin Park <kyungmin.park@samsung.com> Reviewed-by: Mike Turquette <mturquette@ti.com> Acked-by: Kevin Hilman <khilman@ti.com> Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
2011-10-01 22:19:34 +00:00
What: /sys/class/devfreq/.../userspace/set_freq
Date: September 2011
Contact: MyungJoo Ham <myungjoo.ham@samsung.com>
Description:
The /sys/class/devfreq/.../userspace/set_freq shows and
sets the requested frequency for the devfreq object if
userspace governor is in effect.
PM / devfreq: Add sysfs node to expose available frequencies devfreq governors such as ondemand are controlled by a min and max frequency, while governors like userspace governor allow us to set a specific frequency. However, for the same specific device, depending on the SoC, the available frequencies can vary. So expose the available frequencies as a snapshot over sysfs to allow informed decisions. This was inspired by cpufreq framework's equivalent for similar usage sysfs node: scaling_available_frequencies. Cc: Rajagopal Venkat <rajagopal.venkat@linaro.org> Cc: MyungJoo Ham <myungjoo.ham@samsung.com> Cc: Kyungmin Park <kyungmin.park@samsung.com> Cc: "Rafael J. Wysocki" <rjw@sisk.pl> Cc: Kevin Hilman <khilman@ti.com> Cc: linux-pm@vger.kernel.org Cc: linux-kernel@vger.kernel.org Signed-off-by: Nishanth Menon <nm@ti.com> Signed-off-by: MyungJoo Ham <myungjoo.ham@samsung.com>
2012-10-26 00:48:59 +00:00
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.
PM / devfreq: Add sysfs node to expose available governors Now that governor list can be variable, knowing the available governors is useful to be able to select a governor using relevant sysfs node. Cc: Rajagopal Venkat <rajagopal.venkat@linaro.org> Cc: MyungJoo Ham <myungjoo.ham@samsung.com> Cc: Kyungmin Park <kyungmin.park@samsung.com> Cc: "Rafael J. Wysocki" <rjw@sisk.pl> Cc: Kevin Hilman <khilman@ti.com> Cc: linux-pm@vger.kernel.org Cc: linux-kernel@vger.kernel.org Signed-off-by: Nishanth Menon <nm@ti.com> Signed-off-by: MyungJoo Ham <myungjoo.ham@samsung.com>
2012-10-29 20:01:48 +00:00
What: /sys/class/devfreq/.../available_governors
Date: October 2012
Contact: Nishanth Menon <nm@ti.com>
Description:
The /sys/class/devfreq/.../available_governors shows
currently available governors in the system.
PM / devfreq: add comments and Documentation - Added missing ABI documents - Added comments to clarify the objectives of functions Signed-off-by: MyungJoo Ham <myungjoo.ham@samsung.com> Acked-by: Nishanth Menon <nm@ti.com> Acked-by: Rajagopal Venkat <rajagopal.venkat@linaro.org>
2013-02-05 09:40:17 +00:00
What: /sys/class/devfreq/.../min_freq
Date: January 2013
Contact: MyungJoo Ham <myungjoo.ham@samsung.com>
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 <myungjoo.ham@samsung.com>
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.
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