The devfreq framework calls a frequency targeting function with
a flag parameter. Allow the governors to influence that parameter.
Change-Id: I4058bd9dcd027dd246ccdb90d25c68f1dc055901
Signed-off-by: Lucille Sylvester <lsylvest@codeaurora.org>
find_governor_data() was added to the devfreq infrastructure earlier.
It uses an incorrect condition in an if-statement when it searches
a governor by its name. Fixing the condition.
Change-Id: Ib297caad3e23984651217a43d2fdde1f6fcbdf7a
Signed-off-by: Vladimir Razgulin <vrazguli@codeaurora.org>
Set devfreq device min and max frequency limits when device
is added to devfreq, provided frequency table is supplied.
This helps governors to suggest target frequency with in
limits.
Change-Id: Iab24aef59bfeffcfb3c3118c12ba58e25cd9d479
Signed-off-by: Rajagopal Venkat <rajagopal.venkat@linaro.org>
Patch-mainline: linux-pm @ 01/08/13, 05:50
Signed-off-by: Vladimir Razgulin <vrazguli@codeaurora.org>
Level based governors may need to perform this lookup to
interpret the current frequency of the device.
Change-Id: Idf7246b05775a52f088c52b898d98fbab4fd942c
Signed-off-by: Jeremy Gebben <jgebben@codeaurora.org>
Signed-off-by: Vladimir Razgulin <vrazguli@codeaurora.org>
This field is treated as governer specific data for
a devfreq instance. But there's currently no way to
set the correct data when switching governors through
sysfs. Add support for optionally passing a set of
name / data pairs in struct devfreq_dev_profile,
representing the data for each governor.
Change-Id: I5523ce94f8b0045974f0635fb734cb1282512f91
Signed-off-by: Jeremy Gebben <jgebben@codeaurora.org>
Signed-off-by: Vladimir Razgulin <vrazguli@codeaurora.org>
OPP pointers are protected by RCU locks, the pointer validity is
permissible only under the section of rcu_read_lock to rcu_read_unlock
Add documentation to the effect.
Signed-off-by: Nishanth Menon <nm@ti.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Git-commit: bcb27549f4185ca7d0168e201931613706ef2b83
Git-repo: git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
Change-Id: I2c0336d9941f2e1ddb42d97342c95cd61c96af44
Signed-off-by: Jeremy Gebben <jgebben@codeaurora.org>
Governors compiled as modules may use these functions.
Signed-off-by: MyungJoo Ham <myungjoo.ham@samsung.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Git-commit: 6dcdd8e3cadd8dfcfe63d231631d70e2670970f9
Git-repo: git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
Change-Id: Ia16309c731948f96ffb0e4b4bd6b5b3468c89587
Signed-off-by: Jeremy Gebben <jgebben@codeaurora.org>
Use the value obtained from the function instead of -EINVAL.
Signed-off-by: Sachin Kamat <sachin.kamat@linaro.org>
Signed-off-by: MyungJoo Ham <myungjoo.ham@samsung.com>
Git-commit: f9c08e2acbbed19ecafc82e4549b7040cc549216
Git-repo: git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
Change-Id: Ib82c998e0872fcc18b9cbc64bf98a97b374378b0
Signed-off-by: Jeremy Gebben <jgebben@codeaurora.org>
'g' is cast to the error return code. Hence gives the following error
which is fixed by this patch.
drivers/devfreq/devfreq.c:645 devfreq_remove_governor() error:
'g' dereferencing possible ERR_PTR()
Signed-off-by: Sachin Kamat <sachin.kamat@linaro.org>
Signed-off-by: MyungJoo Ham <myungjoo.ham@samsung.com>
Git-commit: b9e1c8e821e7768d5b8629ad7748456af6feece3
Git-repo: git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
Change-Id: I134a794ed4fa48bfb76e4ebbc1408038eb72cd08
Signed-off-by: Jeremy Gebben <jgebben@codeaurora.org>
opp_get_notifier() uses find_device_opp(), which requires to
held rcu_read_lock. In order to keep the notifier-header
valid, we have added rcu_read_lock().
Reported-by: Kees Cook <keescook@chromium.org>
Signed-off-by: MyungJoo Ham <myungjoo.ham@samsung.com>
Git-commit: 389baed01edd298c9622c6e28de5e7e250c8767d
Git-repo: git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
Change-Id: I26a225ffa03003faa3f24822759548f6679ee591
Signed-off-by: Jeremy Gebben <jgebben@codeaurora.org>
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>
Git-commit: 0359d1afe4013d1a216908b6be4c6695a1db6fd6
Git-repo: git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
Change-Id: I7a62cc211f23a795d419bc1f31651687088e6e50
Signed-off-by: Jeremy Gebben <jgebben@codeaurora.org>
Allow devfreq drivers to register a preferred governor name
and when the devfreq governor loads itself at a later point
required drivers are managed appropriately, at the time of
unload of a devfreq governor, stop managing those drivers
as well.
Since the governor structures do not need to be exposed
anymore, remove the definitions and make them static
NOTE: devfreq_list_lock is now used to protect governor
start and stop - as this allows us to protect governors and
devfreq with the proper dependencies as needed.
As part of this change, change the registration of exynos
bus driver to request for ondemand using the governor name.
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>
[Merge conflict resolved by MyungJoo Ham]
Signed-off-by: MyungJoo Ham <myungjoo.ham@samsung.com>
Git-commit: 1b5c1be2c88e8445a20fa1929e26c37e7ca8c926
Git-repo: git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
Change-Id: Ib6a240bba7b284a02e502c489768bb1ea133c65d
Signed-off-by: Jeremy Gebben <jgebben@codeaurora.org>
Currently the opp_find* functions return -ENODEV when:
a) it cant find a device (e.g. request for an OPP search on device
which was not registered)
b) When it cant find a match for the search strategy used
This makes life a little in-efficient for users such as devfreq
to make reasonable judgement before switching search strategies.
So, standardize the return results as following:
-EINVAL for bad pointer parameters
-ENODEV when device cannot be found
-ERANGE when search fails
This has the following benefit for devfreq implementation:
The search fails when an unregistered device pointer is provided.
This is a trigger to change the search direction and search for
a better fit, however, if we cannot differentiate between a valid
search range failure Vs an unregistered device, second search goes
through the same fail return condition. This can be avoided by
appropriate handling of error return code.
With this change, we also fix devfreq for the improved search
strategy with updated error code.
Signed-off-by: Nishanth Menon <nm@ti.com>
Reviewed-by: Kevin Hilman <khilman@ti.com>
Acked-by: MyungJoo Ham <myungjoo.ham@samsung.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Git-commit: 0779726cc265805d0f7c7dd1d791fa4076b31a9a
Git-repo: git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
Change-Id: I95c9d1aaf7ad8dbaff77ab3d57a7b8fe8d599764
Signed-off-by: Jeremy Gebben <jgebben@codeaurora.org>
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>
Git-commit: e552bbaf5b987f57c43e6981a452b8a3c700b1ae
Git-repo: git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
Change-Id: I40b0b252b185e403555f3606ea4a19e29162036e
Signed-off-by: Jeremy Gebben <jgebben@codeaurora.org>
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>
Git-commit: d287de855f97c56ca7146ff627e652bd7cd64f3f
Git-repo: git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
Change-Id: I8d7d37108fe6d7157c6dfd5619e89c1b96ed96b7
Signed-off-by: Jeremy Gebben <jgebben@codeaurora.org>
devfreq_class is used internally by devfreq and has no
need to be globally available.
This also fixes the following sparse warning:
drivers/devfreq/devfreq.c:30:14: warning: symbol 'devfreq_class' was not declared. Should it be static?
Signed-off-by: Nishanth Menon <nm@ti.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Git-commit: 1a1357ea176670867f347419c3345e2becc07338
Git-repo: git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
Change-Id: I550423a78b8a1088ac8572ccba28e2e861783706
Signed-off-by: Jeremy Gebben <jgebben@codeaurora.org>
sscanf returns 0 when an invalid parameter like:
echo -n "a">min_freq
is attempted. Returning back the return result(0) will
cause the command not to return back to command
prompt.
Instead, just return -EINVAL when sscanf does not
return 1.
This is done for min_freq, max_freq and polling_interval
Signed-off-by: Nishanth Menon <nm@ti.com>
Acked-by: MyungJoo Ham <myungjoo.ham@samsung.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Git-commit: 12e26265e6225bf93b2fdc70399774b31e2dd980
Git-repo: git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
Change-Id: I58e88f024887236433b14ee2ab8a5d2ad814083d
Signed-off-by: Jeremy Gebben <jgebben@codeaurora.org>
Parameter documentation needs a ':' for scripts/kernel-doc
to parse properly.
Minor fixes for ones warned by:
./scripts/kernel-doc -text drivers/devfreq/devfreq.c>/dev/null
Signed-off-by: Nishanth Menon <nm@ti.com>
Acked-by: Randy Dunlap <rdunlap@xenotime.net>
Acked-by: MyungJoo Ham <myungjoo.ham@samsung.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Git-commit: c5b4a1c15da3e6f472c6ff1a085a1134d18a1464
Git-repo: git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
Change-Id: Ie5613553bd97884100b4c437bb6a73e7e654603a
Signed-off-by: Jeremy Gebben <jgebben@codeaurora.org>
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>
Git-commit: 7f98a905dca6e4f144cdd4462edeac00c2bdc379
Git-repo: git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
Change-Id: I2e8f27c2ee2529230cb93e135439e012266a66b8
Signed-off-by: Jeremy Gebben <jgebben@codeaurora.org>
Add devfreq suspend/resume apis for devfreq users. This patch
supports suspend and resume of devfreq load monitoring, required
for devices which can idle.
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>
Git-commit: 206c30cfeb7c05dfb9fdfd81b1deb933627e43c1
Git-repo: git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
Change-Id: I34d805d9fc211b8a1e0b15cf9816c37c8f8f9ffa
Signed-off-by: Jeremy Gebben <jgebben@codeaurora.org>
Prepare devfreq core framework to support devices which
can idle. When device idleness is detected perhaps through
runtime-pm, need some mechanism to suspend devfreq load
monitoring and resume back when device is online. Present
code continues monitoring unless device is removed from
devfreq core.
This patch introduces following design changes,
- use per device work instead of global work to monitor device
load. This enables suspend/resume of device devfreq and
reduces monitoring code complexity.
- decouple delayed work based load monitoring logic from core
by introducing helpers functions to be used by governors. This
provides flexibility for governors either to use delayed work
based monitoring functions or to implement their own mechanism.
- devfreq core interacts with governors via events to perform
specific actions. These events include start/stop devfreq.
This sets ground for adding suspend/resume events.
The devfreq apis are not modified and are kept intact.
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>
Git-commit: 7e6fdd4bad033fa2d73716377b184fa975b0d985
Git-repo: git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
[jgebben@codeaurora.org use INIT_DELAYED_WORK_DEFERRABLE macro]
Change-Id: I275b9a3a10b8c676cdbcdd46eaf1a5aa339bfab6
Signed-off-by: Jeremy Gebben <jgebben@codeaurora.org>
The semantics of "target frequency" given to devfreq driver from
devfreq framework has always been interpretted as "at least" or GLB
(greatest lower bound). However, the framework might want the
device driver to limit its max frequency (LUB: least upper bound),
especially if it is given by thermal framework (it's too hot).
Thus, the target fuction should have another parameter to express
whether the framework wants GLB or LUB. And, the additional parameter,
"u32 flags", does it.
With the update, devfreq_recommended_opp() is also updated.
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>
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
The frequency requested to devfreq device driver from devfreq governors
is restricted by min_freq and max_freq input.
Signed-off-by: MyungJoo Ham <myungjoo.ham@samsung.com>
Signed-off-by: Kyungmin Park <kyungmin.park@samsung.com>
In devfreq_remove_device, calling _remove_devfreq will also free devfreq.
Don't dereference devfreq->governor->no_central_polling after _remove_devfreq.
Signed-off-by: Axel Lin <axel.lin@gmail.com>
Acked-by: MyungJoo Ham <myungjoo.ham@samsung.com>
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Added <linux/module.h> and <linux/stat.h> to avoid a compiler error
because linux/irq.h no longer includes linux/module.h after Linux 3.2.
Signed-off-by: MyungJoo Ham <myungjoo.ham@samsung.com>
Signed-off-by: Kyungmin Park <kyungmin.park@samsung.com>
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
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
With OPPs, a device may have multiple operable frequency and voltage
sets. However, there can be multiple possible operable sets and a system
will need to choose one from them. In order to reduce the power
consumption (by reducing frequency and voltage) without affecting the
performance too much, a Dynamic Voltage and Frequency Scaling (DVFS)
scheme may be used.
This patch introduces the DVFS capability to non-CPU devices with OPPs.
DVFS is a techique whereby the frequency and supplied voltage of a
device is adjusted on-the-fly. DVFS usually sets the frequency as low
as possible with given conditions (such as QoS assurance) and adjusts
voltage according to the chosen frequency in order to reduce power
consumption and heat dissipation.
The generic DVFS for devices, devfreq, may appear quite similar with
/drivers/cpufreq. However, cpufreq does not allow to have multiple
devices registered and is not suitable to have multiple heterogenous
devices with different (but simple) governors.
Normally, DVFS mechanism controls frequency based on the demand for
the device, and then, chooses voltage based on the chosen frequency.
devfreq also controls the frequency based on the governor's frequency
recommendation and let OPP pick up the pair of frequency and voltage
based on the recommended frequency. Then, the chosen OPP is passed to
device driver's "target" callback.
When PM QoS is going to be used with the devfreq device, the device
driver should enable OPPs that are appropriate with the current PM QoS
requests. In order to do so, the device driver may call opp_enable and
opp_disable at the notifier callback of PM QoS so that PM QoS's
update_target() call enables the appropriate OPPs. Note that at least
one of OPPs should be enabled at any time; be careful when there is a
transition.
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>
Lucille Sylvester
Vladimir Razgulin
Rajagopal Venkat
Jeremy Gebben
Nishanth Menon
MyungJoo Ham
Sachin Kamat
Jonghwa Lee
Axel Lin