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path: root/drivers/base/power/opp.c
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2015-01-23PM / OPP: Assert RCU lock in exported functionsKrzysztof Kozlowski
Add lockdep asserts for holding the RCU lock when calling dev_pm_opp_get_freq() and dev_pm_opp_get_voltage() to aid in detecting RCU misuses. These are called often after dev_pm_opp_find_freq_ceil/exact() which already asserts for RCU lock. However one could make an error by releasing lock too early - just after dev_pm_opp_find_freq_ceil(). Signed-off-by: Krzysztof Kozlowski <k.kozlowski@samsung.com> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2015-01-23PM / OPP: Update kernel documentationNishanth Menon
kernel doc has gotten bit-rotted over time. Re-sync with Locking and Return information. document all functions properly and ensure that ./scripts/kernel-doc -v ./drivers/base/power/opp.c >/dev/null returns no errors Signed-off-by: Nishanth Menon <nm@ti.com> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2015-01-23PM / OPP: Ensure consistent naming of static functionsNishanth Menon
All exported functions use dev_pm_* prefix and all static functions are now standardized with _ prefix. This is better than having to deal with multiple function naming styles within the same file. Signed-off-by: Nishanth Menon <nm@ti.com> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2015-01-23PM / OPP: export dev_pm_opp_get_notifierNishanth Menon
Allows user drivers such as devfreq to be modules. Signed-off-by: Nishanth Menon <nm@ti.com> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2014-12-18PM / OPP: take RCU lock in dev_pm_opp_get_opp_countDmitry Torokhov
A lot of callers are missing the fact that dev_pm_opp_get_opp_count needs to be called under RCU lock. Given that RCU locks can safely be nested, instead of providing *_locked() API, let's take RCU lock inside dev_pm_opp_get_opp_count() and leave callers as is. Signed-off-by: Dmitry Torokhov <dtor@chromium.org> Acked-by: Viresh Kumar <viresh.kumar@linaro.org> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2014-12-18PM / OPP: fix warning in of_free_opp_table()Dmitry Torokhov
Not having OPP defined for a device is not a crime, we should not splat warning in this case. Also, it seems that we are ready to accept invalid dev (find_device_opp will return ERR_PTR(-EINVAL) then) so let's not crash in dev_name() in such case. Signed-off-by: Dmitry Torokhov <dtor@chromium.org> Acked-by: Viresh Kumar <viresh.kumar@linaro.org> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2014-12-18PM / OPP: add some lockdep annotationsDmitry Torokhov
Certain OPP APIs need to be called under RCU lock; let's add a few rcu_lockdep_assert() calls to warn about potential misuse. Signed-off-by: Dmitry Torokhov <dtor@chromium.org> Acked-by: Viresh Kumar <viresh.kumar@linaro.org> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2014-12-10PM / OPP: do error handling at the bottom of dev_pm_opp_add_dynamic()Viresh Kumar
This makes it less error prone and moves common resource deallocation at a single place. Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2014-12-10PM / OPP: handle allocation of device_opp in a separate routineViresh Kumar
Get the 'device_opp' allocation code into a separate routine to keep only the necessary part in dev_pm_opp_add_dynamic(). Also do s/sizeof(struct device_opp)/sizeof(*dev_opp) and remove the print message on kzalloc() failure as checkpatch warns for that. Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2014-12-10PM / OPP: reuse find_device_opp() instead of duplicating codeViresh Kumar
Reuse find_device_opp() in opp_set_availability() instead of duplicating code. Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2014-12-10PM / OPP: Staticize __dev_pm_opp_remove()Viresh Kumar
Its a local routine and need not be accessible outside of opp.c. Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2014-12-10PM / OPP: replace kfree with kfree_rcu while freeing 'struct device_opp'Viresh Kumar
Somehow one of the instance of freeing resources failed to use kfree_rcu() and used kfree() instead. This might cause problems as the node might be referenced by readers under rcu locks and we must wait for the rcu grace period as well. While we are at it, also update comment over 'struct device_opp' to mention why we are waiting for both rcu and srcu grace periods. Fixes: 129eec55df6a (PM / OPP Introduce APIs to remove OPPs) Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2014-12-10PM / OPP: remove double calls to find_device_opp()Viresh Kumar
By mistake we called find_device_opp() twice in of_free_opp_table(), fix it. Generated diff doesn't show the problem well and so here is the code snippet: void of_free_opp_table(struct device *dev) { struct device_opp *dev_opp = find_device_opp(dev); struct dev_pm_opp *opp, *tmp; /* Check for existing list for 'dev' */ dev_opp = find_device_opp(dev); ... } Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2014-12-10PM / OPP: set new_opp->dev_opp to a valid dev_oppViresh Kumar
We find/allocate dev_opp after using its value to fill new_opp->dev_opp right now. Move this to a later point where dev_opp is valid. Fixes: a7470db6fec4 (PM / OPP don't match for existing OPPs when list is empty) Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2014-11-29PM / OPP replace kfree_rcu() with call_srcu() in opp_set_availability()Viresh Kumar
This existed before we introduced call_srcu() in opp layer to synchronize with srcu_notifier_call_chain() while removing OPPs. And is a potential bug which wasn't noticed earlier. Let fix it as well by using the right API to free OPP. Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2014-11-29PM / OPP Introduce APIs to remove OPPsViresh Kumar
OPPs are created statically (from DT) or dynamically. Currently we don't free OPPs that are created statically, when the module unloads. And so if the module is inserted back again, we get warning for duplicate OPPs as the same were already present. Also, there might be a need to remove dynamic OPPs in future and so API for that is also added. This patch adds helper APIs to remove/free existing static and dynamic OPPs. Because the OPPs are used both under RCU and SRCU, we have to wait for grace period of both. And so are using kfree_rcu() from within call_srcu(). Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2014-11-29PM / OPP mark OPPs as 'static' or 'dynamic'Viresh Kumar
Static OPPs are the ones created from Device Tree entries and dynamic are the ones created at runtime by calling dev_pm_opp_add(). There is a need to distinguish them as we need to free static OPPs from cpufreq drivers when they are removed. So, add another field 'dynamic' in 'struct dev_pm_opp' to keep this information. Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2014-11-29PM / OPP don't match for existing OPPs when list is emptyViresh Kumar
OPP list is guaranteed to be empty when 'dev_opp' is created. And so we don't need to run the comparison loop with existing OPPs. Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2014-11-29PM / OPP rename 'head' as 'rcu_head' or 'srcu_head' based on its typeViresh Kumar
Both 'struct dev_pm_opp' and 'struct device_opp' have member with name 'head' but with different types. This leads to confusion while reading the code. Name them 'rcu_head' and 'srcu_head'. Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2014-06-03Merge branch 'pm-cpufreq'Rafael J. Wysocki
* pm-cpufreq: (28 commits) cpufreq: handle calls to ->target_index() in separate routine cpufreq: s5pv210: drop check for CONFIG_PM_VERBOSE cpufreq: intel_pstate: Remove unused member name of cpudata cpufreq: Break out early when frequency equals target_freq cpufreq: Tegra: drop wrapper around tegra_update_cpu_speed() cpufreq: imx6q: Remove unused include cpufreq: imx6q: Drop devm_clk/regulator_get usage cpufreq: powernow-k8: Suppress checkpatch warnings cpufreq: powernv: make local function static cpufreq: Enable big.LITTLE cpufreq driver on arm64 cpufreq: nforce2: remove DEFINE_PCI_DEVICE_TABLE macro intel_pstate: Add CPU IDs for Broadwell processors cpufreq: Fix build error on some platforms that use cpufreq_for_each_* PM / OPP: Move cpufreq specific OPP functions out of generic OPP library PM / OPP: Remove cpufreq wrapper dependency on internal data organization cpufreq: Catch double invocations of cpufreq_freq_transition_begin/end intel_pstate: Remove sample parameter in intel_pstate_calc_busy cpufreq: Kconfig: Fix spelling errors cpufreq: Make linux-pm@vger.kernel.org official mailing list cpufreq: exynos: Use dev_err/info function instead of pr_err/info ...
2014-05-27PM / OPP: discard duplicate OPPsChander Kashyap
We don't have any protection against addition of duplicate OPPs currently and in case some code tries to add them, it will end up corrupting OPP tables. We need to handle some duplication cases separately as returning error might not be the right thing always. The new list of return values for dev_pm_opp_add() are: 0: On success OR Duplicate OPPs (both freq and volt are same) and opp->available -EEXIST: Freq are same and volt are different OR Duplicate OPPs (both freq and volt are same) and !opp->available -ENOMEM: Memory allocation failure Acked-by: Nishanth Menon <nm@ti.com> Signed-off-by: Chander Kashyap <k.chander@samsung.com> Signed-off-by: Inderpal Singh <inderpal.s@samsung.com> Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2014-05-19PM / OPP: fix incorrect OPP count handling in of_init_opp_tableChander Kashyap
In of_init_opp_table function, if a failure to add an OPP is detected, the count of OPPs, yet to be added is not updated. Fix this by decrementing this count on failure as well. Signed-off-by: Chander Kashyap <k.chander@samsung.com> Signed-off-by: Inderpal Singh <inderpal.s@samsung.com> Acked-by: Viresh Kumar <viresh.kumar@linaro.org> Cc: 3.7+ <stable@vger.kernel.org> # 3.7+ Acked-by: Nishanth Menon <nm@ti.com> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2014-05-07PM / OPP: Move cpufreq specific OPP functions out of generic OPP libraryNishanth Menon
CPUFreq specific helper functions for OPP (Operating Performance Points) now use generic OPP functions that allow CPUFreq to be be moved back into CPUFreq framework. This allows for independent modifications or future enhancements as needed isolated to just CPUFreq framework alone. Here, we just move relevant code and documentation to make this part of CPUFreq infrastructure. Cc: Kevin Hilman <khilman@deeprootsystems.com> 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>
2014-05-07PM / OPP: Remove cpufreq wrapper dependency on internal data organizationNishanth Menon
CPUFREQ custom functions for OPP (Operating Performance Points) currently exist inside the OPP library. These custom functions currently depend on internal data structures to pick up OPP information to create the cpufreq table. For example, the cpufreq table is created precisely in the same order of how OPP entries are stored inside the list implementation. This kind of tight interdependency is purely artificial since the same functionality can be achieved using the generic OPP functions meant to do the same. This interdependency also limits the independent modification of cpufreq and OPP library. So use the generic dev_pm_opp_find_freq_ceil function that achieves the table organization as we currently use. As a result of this, we dont need to use the internal device_opp structure anymore, and we hence we can switch over to rcu lock instead of the mutex holding the internal list lock. This breaking of dependency on internal data structure imposes no change to usage of these. NOTE: This change is a precursor to moving this cpufreq specific logic out of the generic library into cpufreq. Cc: Kevin Hilman <khilman@deeprootsystems.com> 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>
2014-02-14drivers/base: delete non-required instances of include <linux/init.h>Paul Gortmaker
None of these files are actually using any __init type directives and hence don't need to include <linux/init.h>. Most are just a left over from __devinit and __cpuinit removal, or simply due to code getting copied from one driver to the next. Cc: Len Brown <len.brown@intel.com> Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com> Acked-by: Pavel Machek <pavel@ucw.cz> Acked-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Acked-by: Mark Brown <broonie@linaro.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-10-25PM / OPP: rename header to linux/pm_opp.hNishanth Menon
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>
2013-10-25PM / OPP: rename data structures to dev_pm equivalentsNishanth Menon
Since Operating Performance Points (OPP) data structures are specific to device specific power management, be specific and rename opp_* data structures in OPP library with dev_pm_opp_* equivalent. Affected structures are: struct opp enum opp_event Minor checkpatch warning resulting of this change was fixed as well. 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>
2013-10-25PM / OPP: rename functions to dev_pm_opp*Nishanth Menon
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>
2013-08-06PM / OPP: Export opp_add()Viresh Kumar
Export opp_add() so that modules can use it. Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org> Acked-by: Nishanth Menon <nm@ti.com> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2013-06-04cpufreq: rename index as driver_data in cpufreq_frequency_tableViresh Kumar
The "index" field of struct cpufreq_frequency_table was never an index and isn't used at all by the cpufreq core. It only is useful for cpufreq drivers for their internal purposes. Many people nowadays blindly set it in ascending order with the assumption that the core will use it, which is a mistake. Rename it to "driver_data" as that's what its purpose is. All of its users are updated accordingly. [rjw: Changelog] Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org> Acked-by: Simon Horman <horms+renesas@verge.net.au> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2013-04-05PM / OPP: add documentation to RCU head in struct oppNishanth Menon
commit dde8437 (PM / OPP: RCU reclaim) introduced rcu_head for struct opp. This aids freeing using kfree_rcu. However, we missed adding documentation for the same. This generates kernel doc warning: Warning(drivers/base/power/opp.c:70): No description found for parameter 'head' Add documentation as appropriate. [rjw: Changelog] Signed-off-by: Nishanth Menon <nm@ti.com> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2013-02-02PM / OPP: Export more symbols for module usageMark Langsdorf
Export cpufreq helpers in OPP to make the cpufreq-core0 and highbank-cpufreq drivers loadable as modules. Signed-off-by: Mark Langsdorf <mark.langsdorf@calxeda.com> Signed-off-by: Nishanth Menon <nm@ti.com> Acked-by: Shawn Guo <shawn.guo@linaro.org> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2013-02-02PM / OPP: switch exported symbols to GPL variantNishanth Menon
We are GPLV2 library, so be clear in the symbols exported as well. Signed-off-by: Nishanth Menon <nm@ti.com> Acked-by: Shawn Guo <shawn.guo@linaro.org> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2012-11-15PM / OPP: using kfree_rcu() to simplify the codeWei Yongjun
The callback function of call_rcu() just calls a kfree(), so we can use kfree_rcu() instead of call_rcu() + callback function. dpatch engine is used to auto generate this patch. (https://github.com/weiyj/dpatch) Signed-off-by: Wei Yongjun <yongjun_wei@trendmicro.com.cn> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2012-11-15PM / OPP: predictable fail results for opp_find* functions, v2Nishanth Menon
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>
2012-11-15PM / OPP: Export symbols for module usage.Liam Girdwood
Export the OPP functions for use by driver modules. 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 [nm@ti.com: expansion of functions exported] Signed-off-by: Nishanth Menon <nm@ti.com> Signed-off-by: Liam Girdwood <lrg@ti.com> Acked-by: Kevin Hilman <khilman@ti.com> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2012-11-15PM / OPP: RCU reclaimVincent Guittot
synchronize_rcu() blocks the caller of opp_enable/disbale for a complete grace period. This blocking duration prevents any intensive use of the functions. Replace synchronize_rcu() by call_rcu() which will call our function for freeing the old opp element. The duration of opp_enable() and opp_disable() will be no more dependant of the grace period. Signed-off-by: Vincent Guittot <vincent.guittot@linaro.org> Reviewed-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2012-09-09PM / OPP: Initialize OPP table from device treeShawn Guo
With a lot of devices booting from device tree nowadays, it requires that OPP table can be initialized from device tree. The patch adds a helper function of_init_opp_table together with a binding doc for that purpose. Signed-off-by: Shawn Guo <shawn.guo@linaro.org> Acked-by: Rob Herring <rob.herring@calxeda.com> Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
2012-03-11device.h: cleanup users outside of linux/include (C files)Paul Gortmaker
For files that are actively using linux/device.h, make sure that they call it out. This will allow us to clean up some of the implicit uses of linux/device.h within include/* without introducing build regressions. Yes, this was created by "cheating" -- i.e. the headers were cleaned up, and then the fallout was found and fixed, and then the two commits were reordered. This ensures we don't introduce build regressions into the git history. Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
2011-11-08PM / OPP: Use ERR_CAST instead of ERR_PTR(PTR_ERR())Thomas Meyer
Use ERR_CAST inlined function instead of ERR_PTR(PTR_ERR(...)) [The semantic patch that makes this change is available in scripts/coccinelle/api/err_cast.cocci. More information about semantic patching is available at http://coccinelle.lip6.fr/] Signed-off-by: Thomas Meyer <thomas@m3y3r.de> Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
2011-09-30PM / OPP: Add OPP availability change notifier.MyungJoo Ham
The patch enables to register notifier_block for an OPP-device in order to get notified for any changes in the availability of OPPs of the device. For example, if a new OPP is inserted or enable/disable status of an OPP is changed, the notifier is executed. This enables the usage of opp_add, opp_enable, and opp_disable to directly take effect with any connected entities such as cpufreq or devfreq. 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> Reviewed-by: Kevin Hilman <khilman@ti.com> Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
2011-07-26drivers/base/power/opp.c: fix dev_opp initial valueJonghwan Choi
Dev_opp initial value shoule be ERR_PTR(), IS_ERR() is used to check error. Signed-off-by: Jonghwan Choi <jhbird.choi@samsung.com> Cc: "Rafael J. Wysocki" <rjw@sisk.pl> Cc: Greg KH <greg@kroah.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2011-07-15PM / OPP: Introduce function to free cpufreq tableNishanth Menon
cpufreq table allocated by opp_init_cpufreq_table is better freed by OPP layer itself. This allows future modifications to the table handling to be transparent to the users. Signed-off-by: Nishanth Menon <nm@ti.com> Acked-by: Kevin Hilman <khilman@ti.com> Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
2011-03-15PM / OPP: opp_find_freq_exact() documentation fixNishanth Menon
opp_find_freq_exact() documentation has is_available instead of available. This also fixes warning with the kernel-doc: scripts/kernel-doc drivers/base/power/opp.c >/dev/null Warning(drivers/base/power/opp.c:246): No description found for parameter 'available' Warning(drivers/base/power/opp.c:246): Excess function parameter 'is_available' description in 'opp_find_freq_exact' Signed-off-by: Nishanth Menon <nm@ti.com> Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
2010-10-17PM: Introduce library for device-specific OPPs (v7)Nishanth Menon
SoCs have a standard set of tuples consisting of frequency and voltage pairs that the device will support per voltage domain. These are called Operating Performance Points or OPPs. The actual definitions of OPP varies over silicon versions. For a specific domain, we can have a set of {frequency, voltage} pairs. As the kernel boots and more information is available, a default set of these are activated based on the precise nature of device. Further on operation, based on conditions prevailing in the system (such as temperature), some OPP availability may be temporarily controlled by the SoC frameworks. To implement an OPP, some sort of power management support is necessary hence this library depends on CONFIG_PM. Contributions include: Sanjeev Premi for the initial concept: http://patchwork.kernel.org/patch/50998/ Kevin Hilman for converting original design to device-based. Kevin Hilman and Paul Walmsey for cleaning up many of the function abstractions, improvements and data structure handling. Romit Dasgupta for using enums instead of opp pointers. Thara Gopinath, Eduardo Valentin and Vishwanath BS for fixes and cleanups. Linus Walleij for recommending this layer be made generic for usage in other architectures beyond OMAP and ARM. Mark Brown, Andrew Morton, Rafael J. Wysocki, Paul E. McKenney for valuable improvements. Discussions and comments from: http://marc.info/?l=linux-omap&m=126033945313269&w=2 http://marc.info/?l=linux-omap&m=125482970102327&w=2 http://marc.info/?t=125809247500002&r=1&w=2 http://marc.info/?l=linux-omap&m=126025973426007&w=2 http://marc.info/?t=128152609200064&r=1&w=2 http://marc.info/?t=128468723000002&r=1&w=2 incorporated. v1: http://marc.info/?t=128468723000002&r=1&w=2 Signed-off-by: Nishanth Menon <nm@ti.com> Signed-off-by: Kevin Hilman <khilman@deeprootsystems.com> Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
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