This driver registers a devfreq device that allows devfreq governors to
scale the frequency of a device clock. This single driver can be used to
support multiple devices as long as those devices don't have a need or
mechanism to monitor their load and use clock APIs to control their
device/core clock.
If devices need to support device specific status monitoring, they could
extend this driver to allow registering device specific status monitoring
funtions or write their own specific devfreq device driver.
Change-Id: Ie1797acf7b35cac6dc49428e270c23082634eb1e
Signed-off-by: Saravana Kannan <skannan@codeaurora.org>
The cpu_khz variable would be uninitialized when debug messages are printed
for OFFLINE CPUs. Fix that by initializing it to 0.
Change-Id: Ic707c13b1048625c0ecc0b0057af2f84f17462f6
Signed-off-by: Saravana Kannan <skannan@codeaurora.org>
This devfreq governor is a generic implementation that can scale any
devfreq device based on the current CPU frequency of all ONLINE CPUs. It
allows for specifying CPU freq to devfreq mapping for specific devices.
When such a mapping is not present, it defaults to scaling the device
frequency in proportion to the CPU frequency.
Change-Id: I8d3b1fea26572defbad2ce8b6cf87930caa25ca6
Signed-off-by: Saravana Kannan <skannan@codeaurora.org>
In order to share devfreq_cpubw among all targets, it needs to be
moved outside arch/arm/mach-msm directory. Move the file and
Kconfig to drivers/devfreq.
Change-Id: I4dd476b315b04f84b07855bec3ed5b6061549ea9
Signed-off-by: Junjie Wu <junjiew@codeaurora.org>
Some devices use freq_table instead of OPP. For those devices, the
available_frequencies file shows up empty. Fix that by using freq_table to
generate the available_frequencies data when OPP is not present.
Change-Id: Ibea8b388ee81c55d2eeddd8a1e2c18c91faed8c7
Signed-off-by: Saravana Kannan <skannan@codeaurora.org>
Sometimes GPU busy time is very low during sampling. Accumulate
the statistics and send them with the next sample.
Change-Id: I77e568b48afc3a4922c7c341d9478705b7ae3a30
Signed-off-by: Suman Tatiraju <sumant@codeaurora.org>
Since various hardware platforms might have different ways of monitoring
the CPU bandwidth, make the cpubw_hwmon governor hardware agnostic so that
it can be reused across these hardware platforms.
Change-Id: If7af01537dbf1df66551bea2bc73232d9e9264f7
Signed-off-by: Saravana Kannan <skannan@codeaurora.org>
The current devfreq_update_status() has the following bugs:
- When the new frequency doesn't have a valid level, the time spent in the
new frequency is counted towards the next valid frequency switch instead
of being ignored.
- The time spent on the previous frequency is added to the new frequency's
stats instead of the previous frequency's stats.
This patch fixes all of this.
Change-Id: I7bbdafca78d1565cdbf815356556fe6d6cca9e3f
Signed-off-by: Saravana Kannan <skannan@codeaurora.org>
Architecutural changes in the ARM Linux kernel tree mandate the
eventual removal of the mach-* directories. Move mach/cpufreq to
driver/cpufreq/. Also move related header to include/linux.
Change-Id: I6dcf69e275b7ca7ba913e945353a42f0d6321731
Signed-off-by: Junjie Wu <junjiew@codeaurora.org>
The previous_freq value for a device could be an invalid frequency that
results in a error value being returned from devfreq_get_freq_level().
Check for an error value before using that to index into the transition
table.
Not doing this check will result in memory corruption when previous_freq is
not a valid frequency.
Signed-off-by: Saravana Kannan <skannan@codeaurora.org>
Change-Id: Ia9f9f3dabf14b26c4dff54fb2bac3e77f33458c0
Architectural changes in the ARM Linux kernel tree mandate
the eventual removal of the mach-* directories. Move the
scm driver to drivers/soc/qcom and the scm header to
include/soc/qcom to support that removal.
Change-Id: Ie660d0566de35045c1ba73fcddeda99efacf057e
Signed-off-by: Vikram Mulukutla <markivx@codeaurora.org>
The decay rate tunable is used to compute the current averaged bandwidth
use, but the calculated value is never used. Fix this by using the
calculated averaged bandwidth instead of the instantaneous measured
bandwidth when computing the AB and IB votes.
Change-Id: Ic0ba3ce0d98f0ec185349fe6d86c4af26f222ff2
Signed-off-by: Saravana Kannan <skannan@codeaurora.org>
devfreq already provides a sysfs interface for changing polling/sampling
period. So, there is no need for the governor to separately expose
sampling_ms. Also, sampling_ms had to be explicitly updated whenever
polling_ms was updated for the governor to function correctly. Make the
interface simpler by combining sample_ms with polling_interval control
provided by devfreq.
The rounding of freq to multiples of bw_step is unnecessary since the
devfreq device already does the rounding to the next valid level. Rounding
of AB to multiples of bw_step is still necessary since it's a vote that's
summed up and doesn't have a direct 1-to-1 mapping to frequencies.
Also update default bw_step to 190 MB/s instead of 200 MB/s to account for
the fact that MB/s to MHz conversion needs to take into account the
difference in the meaning of M (2^20 vs 10^6) between MB and MHz. Similarly
also update io_percent to 16.
Change-Id: I5fea989c647955103de3813be8eb9ec612f131bc
Signed-off-by: Saravana Kannan <skannan@codeaurora.org>
Add new flag "simple_scaling" to on demand governor so that
the clocks can be scaled up only when the load is more than
up threshold and can be scaled down only when the load is less
than down differential data as provided within
struct devfreq_simple_ondemand_data.
Change-Id: Ibc6ab6297c1b64b6e6eaaa76d735d0b9ae0f6477
Signed-off-by: Sahitya Tummala <stummala@codeaurora.org>
Since Operating Performance Points (OPP) functions are specific
to device specific power management, be specific and rename opp.h
to pm_opp.h
Reported-by: Randy Dunlap <rdunlap@infradead.org>
Signed-off-by: Nishanth Menon <nm@ti.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Git-commit: e4db1c7439b31993a4886b273bb9235a8eea82bf
Git-repo: git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
[junjiew@codeaurora.org: resolve trivial merge conflicts]
Signed-off-by: Junjie Wu <junjiew@codeaurora.org>
Since Operating Performance Points (OPP) functions are specific to
device specific power management, be specific and rename opp_*
accessors in OPP library with dev_pm_opp_* equivalent.
Affected functions are:
opp_get_voltage
opp_get_freq
opp_get_opp_count
opp_find_freq_exact
opp_find_freq_floor
opp_find_freq_ceil
opp_add
opp_enable
opp_disable
opp_get_notifier
opp_init_cpufreq_table
opp_free_cpufreq_table
Reported-by: Randy Dunlap <rdunlap@infradead.org>
Signed-off-by: Nishanth Menon <nm@ti.com>
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Git-commit: 5d4879cda67b09f086807821cf594ee079d6dfbe
Git-repo: git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
[junjiew@codeaurora.org: resolve trivial merge conflicts]
Signed-off-by: Junjie Wu <junjiew@codeaurora.org>
The CPUBW HW monitor devfreq governor uses the Krait L2 PM counters to
determine the bandwidth needed by the Krait CPU subsystem. This governor
can be used in conjunction with the CPUBW devfreq device to dynamically
scale the DDR frequency based on the demand/actual usage from the Krait CPU
subsystem. Since this governor uses the Krait L2 PM counters it can
conflict with certain profiling tools.
The Krait L2 performance monitor counters have the capability to count the
no. of read/write transactions going out the master ports. They also have
the capability to raise interrupts when they overflow. This driver uses
those counters to determine the true usage of DDR from the Krait processor
subsystem and then recommends CPU DDR BW votes based on the measured values
and the following tunable parameters.
The driver provides various tunables that allow it to be tuned more in
favor of power or performance:
- io_percent: The percentage of the CPU time that can be spent waiting on
memory I/O. Lower value is better performance and worse power.
- sample_ms: The sampling period in milliseconds. This only affects the
sampling period when DDR use is ramping down or is increasing very slowly
(See tolerance_percent).
- tolerance_percent: The minimum increase in DDR use, compared to previous
sample, that will trigger an IRQ to immediately bump up the bandwidth
vote. It's expressed as a percentage of the previous sampled DDR use.
- decay_rate: The parameter controls the rate at which the history is
forgotten when ramping down. This is expressed as a percentage of history
to be forgotten. So 100% means ignore history, 0% mean never forget the
historical max. The default 90% means forget 90% of history each time.
- guard_band_mbps: This is a margin that's added to the measured BW (and
hence also the Bus BW votes) that's present to account for the time it
takes to ramp up the DDR BW while the CPU continues to use the DDR.
- bw_step: All BW votes are rounded up to multiples of bw_step. The default
value is 200 MB/s that turns out to ~25 or 12.5 MHz based on the SoC. A
smaller value would mean more frequent bus BW changes. A higher value
would mean less frequent BW vote updates, but also means at times an
unnecessarily higher BW vote (due to the rounding up).
Change-Id: I88629a3e545cdca7160af8f8ca616ecc949d9947
Signed-off-by: Saravana Kannan <skannan@codeaurora.org>
The MSM CPUfreq devfreq governor determines the CPU to DDR bandwidth vote
based on the current CPU frequency of all the active CPUs.
This functionality used to be a part of the MSM CPUfreq driver that
directly voted for the CPU to DDR bandwidth using MSM bus scaling APIs.
This refactor decouples CPU to DDR BW scaling from CPU frequency and allows
switch between various CPU BW governors.
The bandwidth values in the msm-cpufreq table have to be updated since the
new CPU BW driver does the MBps to Bps conversion correctly. The MSM
CPUfreq driver used to do * 1000 * 1000 to convert from MBps to Bps instead
of doing * 1024 * 1024.
Change-Id: I184f09d628a1b27d52506d2f760d65831f1a1110
Signed-off-by: Saravana Kannan <skannan@codeaurora.org>
The new flag for the devfreq profile->target() function is used
by the performance governor to notify the driver that the device
should wakeup on the max frequency.
Change-Id: I91c2d649177bdd1841a087a2125d1cdbc979f5c1
Signed-off-by: Vladimir Razgulin <vrazguli@codeaurora.org>
Expected behavior of GPU DCVS is to immediately bump the frequency
to turbo upon encountering a long block of busy processing. The
current code just raises the frequency by one level.
Change-Id: Ida953bb7be8a976da5400328a1c91083499e0fa0
Signed-off-by: Lucille Sylvester <lsylvest@codeaurora.org>
Use the vbif performance counter which counts bus busy cycles
to determine the requested bus bandwidth vote at a given
GPU frequency.
Change-Id: I18915ef8a2be75a7ef5795a6030a1f2ddd09a967
CRs-fixed: 574420
Signed-off-by: Lucille Sylvester <lsylvest@codeaurora.org>
Use a bus specific speed flag rather than overloading
the least upper bound flag.
Change-Id: I343726e6e0d9885f39c343ed56c1667ab2008aee
Signed-off-by: Lucille Sylvester <lsylvest@codeaurora.org>
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>
This governor can be used to control adreno GPUs.
It is unlikely to be useful for other devices.
Change-Id: Icf481322454b814d2f41019f2f01286062409952
Signed-off-by: Jeremy Gebben <jgebben@codeaurora.org>
Signed-off-by: Vladimir Razgulin <vrazguli@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>
The predefined performance and powersave governors set the device
frequency on their startup only. That's not enough because the
frequency might have changed after device suspend-resume. With this
fix the governors re-set the required device frequency every time
a device get resumed.
Change-Id: I47ac877fc9e2cfbfc4a46cc676d6f2f838cd41d6
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 cannot be expected to be valid beyond the boundary
of rcu_read_lock and rcu_read_unlock. Unfortunately, the current
exynos4 busfreq driver does not honor the usage constraint and stores
the OPP pointer in struct busfreq_data. This could potentially
become invalid later such as: across devfreq opp change decisions,
resulting in unpredictable behavior.
To fix this, we introduce a busfreq specific busfreq_opp_info
structure which is used to handle OPP information. OPP information
is de-referenced to voltage and frequency pairs as needed into
busfreq_opp_info structure and used as needed.
Signed-off-by: Nishanth Menon <nm@ti.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
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>
CONFIG_HOTPLUG is going away as an option. As a result, the __dev*
markings need to be removed.
This change removes the use of __devinit, __devexit_p, __devinitdata,
__devinitconst, and __devexit from these drivers.
Based on patches originally written by Bill Pemberton, but redone by me
in order to handle some of the coding style issues better, by hand.
Cc: Bill Pemberton <wfp5p@virginia.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.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>
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>
'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>
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>
I fixed the following check item (via checkpatch.pl --strict option):
CHECK: Alignment should match open parenthesis
Signed-off-by: Sangho Yi <antiroot@gmail.com>
[Merge conflict resolved]
Signed-off-by: MyungJoo Ham <myungjoo.ham@samsung.com>
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>
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>
Add GPL module license and remove the static build
restrictions for building governors. This allows governors now
to be loaded on a need basis and reloaded independently of kernel
build
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>
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>
With the new registration functions, governors can be now
registered with devfreq framework.
NOTE: generates 'discards qualifiers from pointer target type'
build warnings, which the next patche in this series fixes
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>
Add devfreq_add_governor and devfreq_remove_governor which
can be invoked by governors to register with devfreq.
This sets up the stage to dynamically switch governors and
allow governors to be dynamically loaded as well.
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>
Allow update_devfreq to be used by devfreq governor built
as modules
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>
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>
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>
devm_* functions are device managed functions and make cleanup code
simpler and smaller.
devm_kzalloc and devm_regulator_get functions are used.
Signed-off-by: Sachin Kamat <sachin.kamat@linaro.org>
[renamed the patch title by MyungJoo Ham]
Signed-off-by: MyungJoo Ham <myungjoo.ham@samsung.com>
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>
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>
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>
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>
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>
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>
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>
Initalizers for deferrable delayed_work are confused.
* __DEFERRED_WORK_INITIALIZER()
* DECLARE_DEFERRED_WORK()
* INIT_DELAYED_WORK_DEFERRABLE()
Rename them to
* __DEFERRABLE_WORK_INITIALIZER()
* DECLARE_DEFERRABLE_WORK()
* INIT_DEFERRABLE_WORK()
This patch doesn't cause any functional changes.
Signed-off-by: Tejun Heo <tj@kernel.org>
* Implementation of opportunistic suspend (autosleep) and user space interface
for manipulating wakeup sources.
* Hibernate updates from Bojan Smojver and Minho Ban.
* Updates of the runtime PM core and generic PM domains framework related to
PM QoS.
* Assorted fixes.
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Merge tag 'pm-for-3.5' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm
Pull power management updates from Rafael Wysocki:
- Implementation of opportunistic suspend (autosleep) and user space
interface for manipulating wakeup sources.
- Hibernate updates from Bojan Smojver and Minho Ban.
- Updates of the runtime PM core and generic PM domains framework
related to PM QoS.
- Assorted fixes.
* tag 'pm-for-3.5' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm: (25 commits)
epoll: Fix user space breakage related to EPOLLWAKEUP
PM / Domains: Make it possible to add devices to inactive domains
PM / Hibernate: Use get_gendisk to verify partition if resume_file is integer format
PM / Domains: Fix computation of maximum domain off time
PM / Domains: Fix link checking when add subdomain
PM / Sleep: User space wakeup sources garbage collector Kconfig option
PM / Sleep: Make the limit of user space wakeup sources configurable
PM / Documentation: suspend-and-cpuhotplug.txt: Fix typo
PM / Domains: Cache device stop and domain power off governor results, v3
PM / Domains: Make device removal more straightforward
PM / Sleep: Fix a mistake in a conditional in autosleep_store()
epoll: Add a flag, EPOLLWAKEUP, to prevent suspend while epoll events are ready
PM / QoS: Create device constraints objects on notifier registration
PM / Runtime: Remove device fields related to suspend time, v2
PM / Domains: Rework default domain power off governor function, v2
PM / Domains: Rework default device stop governor function, v2
PM / Sleep: Add user space interface for manipulating wakeup sources, v3
PM / Sleep: Add "prevent autosleep time" statistics to wakeup sources
PM / Sleep: Implement opportunistic sleep, v2
PM / Sleep: Add wakeup_source_activate and wakeup_source_deactivate tracepoints
...
Performance and powersave governor's get_target_freq
is not called if driver chooses one of these two governors.
Add init function in governor profile to call update_devfreq
which will call get_target_freq subsequently.
Signed-off-by: Xiaoguang Chen <chenxg@marvell.com>
Acked-by: MyungJoo Ham <myungjoo.ham@samsung.com>
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Quite a bit of code gets removed, and some stuff moved around, mostly
the old samsung s3c24xx stuff. There should be no functional changes
in this series otherwise. Some cleanups have dependencies on other
arm-soc branches and will be sent in the second round.
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
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Merge tag 'cleanup' of git://git.kernel.org/pub/scm/linux/kernel/git/arm/arm-soc
Pull "ARM: global cleanups" from Arnd Bergmann:
"Quite a bit of code gets removed, and some stuff moved around, mostly
the old samsung s3c24xx stuff. There should be no functional changes
in this series otherwise. Some cleanups have dependencies on other
arm-soc branches and will be sent in the second round.
Signed-off-by: Arnd Bergmann <arnd@arndb.de>"
Fixed up trivial conflicts mainly due to #include's being changes on
both sides.
* tag 'cleanup' of git://git.kernel.org/pub/scm/linux/kernel/git/arm/arm-soc: (121 commits)
ep93xx: Remove unnecessary includes of ep93xx-regs.h
ep93xx: Move EP93XX_SYSCON defines to SoC private header
ep93xx: Move crunch code to mach-ep93xx directory
ep93xx: Make syscon access functions private to SoC
ep93xx: Configure GPIO ports in core code
ep93xx: Move peripheral defines to local SoC header
ep93xx: Convert the watchdog driver into a platform device.
ep93xx: Use ioremap for backlight driver
ep93xx: Move GPIO defines to gpio-ep93xx.h
ep93xx: Don't use system controller defines in audio drivers
ep93xx: Move PHYS_BASE defines to local SoC header file
ARM: EXYNOS: Add clock register addresses for EXYNOS4X12 bus devfreq driver
ARM: EXYNOS: add clock registers for exynos4x12-cpufreq
PM / devfreq: update the name of EXYNOS clock registers that were omitted
PM / devfreq: update the name of EXYNOS clock register
ARM: EXYNOS: change the prefix S5P_ to EXYNOS4_ for clock
ARM: EXYNOS: use static declaration on regarding clock
ARM: EXYNOS: replace clock.c for other new EXYNOS SoCs
ARM: OMAP2+: Fix build error after merge
ARM: S3C24XX: remove call to s3c24xx_setup_clocks
...
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>
In the commit, "PM / devfreq: update the name of EXYNOS clock register"
ommitted one register.
Signed-off-by: MyungJoo Ham <myungjoo.ham@samsung.com>
Signed-off-by: Kukjin Kim <kgene.kim@samsung.com>
According to replacing the name of EXYNOS clock registers,
this patch updates exynos4_bus.c file where it is used.
Acked-by: MyungJoo Ham <myungjoo.ham@samsung.com>
Cc: Kyungmin Park <kyungmin.park@samsung.com>
Signed-off-by: Kukjin Kim <kgene.kim@samsung.com>
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>
This driver can only be built-in, it does not make sense to add modalias for
it (in addition to being incorrect, the platform modalias needs to be prefixed
with "platform:").
Signed-off-by: Axel Lin <axel.lin@gmail.com>
Signed-off-by: MyungJoo Ham <myungjoo.ham@samsung.com>
* 'devfreq-for-next' of git://git.infradead.org/users/kmpark/linux-samsung: (765 commits)
PM/Devfreq: Add Exynos4-bus device DVFS driver for Exynos4210/4212/4412.
pci: Fix hotplug of Express Module with pci bridges
i2c-eg20t: correct the driver init order of pch_i2c_probe()
I2C: OMAP: fix FIFO usage for OMAP4
i2c-s3c2410: Fix return code of s3c24xx_i2c_parse_dt_gpio
i2c: i2c-s3c2410: Add a cpu_relax() to busy wait for bus idle
Linux 3.2-rc6
Revert "drm/i915: fix infinite recursion on unbind due to ilk vt-d w/a"
btrfs: lower the dirty balance poll interval
drm/i915/dp: Dither down to 6bpc if it makes the mode fit
drm/i915: enable semaphores on per-device defaults
drm/i915: don't set unpin_work if vblank_get fails
drm/i915: By default, enable RC6 on IVB and SNB when reasonable
iommu: Export intel_iommu_enabled to signal when iommu is in use
drm/i915/sdvo: Include LVDS panels for the IS_DIGITAL check
drm/i915: prevent division by zero when asking for chipset power
drm/i915: add PCH info to i915_capabilities
drm/i915: set the right SDVO transcoder for CPT
drm/i915: no-lvds quirk for ASUS AT5NM10T-I
sched: Fix select_idle_sibling() regression in selecting an idle SMT sibling
...
Exynos4-bus device devfreq driver add DVFS capability for
Exynos4210/4212/4412-Bus (memory). The driver monitors PPMU counters of memory
controllers and adjusts operating frequencies and voltages with OPP.
For Exynos4210, vdd_int is controlled. For exynos4412/4212, vdd_mif and
vdd_int are controlled.
Dependency (CONFIG_EXYNOS_ASV):
Exynos4 ASV driver has been posted in the mailing list; however, it
si not yet upstreamed. Although the current revision of Exynos4 ASV
patch does not contain "CONFIG_EXYNOS_ASV", we have added the symbol
to hide the dependent from compilers for now. As soon as Exynos4 ASV
drivers are merged, the #ifdef statement will be removed or the
name will be changed.
However, enabling ASV is essential in most Exynos4 chips to reduce
the power consumption of Exynos4210 because without ASV, this Devfreq
driver assumes the worst case scenario, which consumes more power.
Signed-off-by: MyungJoo Ham <myungjoo.ham@samsung.com>
Signed-off-by: Kyungmin Park <kyungmin.park@samsung.com>
---
Changes from v1
- Support 4212 and 4412 as well as 4210.
I think this change improves code readability.
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>
Devfreq does not depend on OPP. The dependency is removed.
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>
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>
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>
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>
Saravana Kannan