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path: root/Documentation/cpu-freq/cpu-drivers.txt
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2018-04-10cpufreq: Drop cpufreq_table_validate_and_show()Viresh Kumar
This isn't used anymore. Remove the helper and update documentation accordingly. Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2018-02-08cpufreq: Add and use cpufreq_for_each_{valid_,}entry_idx()Dominik Brodowski
Pointer subtraction is slow and tedious. Therefore, replace all instances where cpufreq_for_each_{valid_,}entry loops contained such substractions with an iteration macro providing an index to the frequency_table entry. Suggested-by: Al Viro <viro@ZenIV.linux.org.uk> Link: http://lkml.kernel.org/r/20180120020237.GM13338@ZenIV.linux.org.uk Acked-by: Viresh Kumar <viresh.kumar@linaro.org> Signed-off-by: Dominik Brodowski <linux@dominikbrodowski.net> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2017-03-09Documentation: cpu-freq: cpu-drivers: Fix repetition of word 'to'sayli karnik
The patch replaces 'to to' with 'to' in the documentation. Signed-off-by: sayli karnik <karniksayli1995@gmail.com> Acked-by: Viresh Kumar <viresh.kumar@linaro.org> Signed-off-by: Jonathan Corbet <corbet@lwn.net>
2017-02-03cpufreq: Documentation: Updates based on current codeViresh Kumar
The cpufreq core has gone though lots of updates in recent times, but on many occasions the documentation wasn't updated along with the code. This patch tries to catchup the documentation with the code. Also add Rafael and Viresh as the contributors to the documentation. Based on a patch from Claudio Scordino. Signed-off-by: Claudio Scordino <claudio@evidence.eu.com> Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2016-06-09cpufreq: Return index from cpufreq_frequency_table_target()Viresh Kumar
This routine can't fail unless the frequency table is invalid and doesn't contain any valid entries. Make it return the index and WARN() in case it is used for an invalid table. Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2016-06-09cpufreq: Drop freq-table param to cpufreq_frequency_table_target()Viresh Kumar
The policy already has this pointer set, use it instead. Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2016-06-02cpufreq: Unexport cpufreq_frequency_table_cpuinfo()Viresh Kumar
All cpufreq drivers with a freq-table are migrated to use cpufreq_table_validate_and_show() long back and the routine cpufreq_frequency_table_cpuinfo() isn't used outside of cpufreq core now. Unexport it and update Documentation as well. Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2014-06-05cpufreq: add support for intermediate (stable) frequenciesViresh Kumar
Douglas Anderson, recently pointed out an interesting problem due to which udelay() was expiring earlier than it should. While transitioning between frequencies few platforms may temporarily switch to a stable frequency, waiting for the main PLL to stabilize. For example: When we transition between very low frequencies on exynos, like between 200MHz and 300MHz, we may temporarily switch to a PLL running at 800MHz. No CPUFREQ notification is sent for that. That means there's a period of time when we're running at 800MHz but loops_per_jiffy is calibrated at between 200MHz and 300MHz. And so udelay behaves badly. To get this fixed in a generic way, introduce another set of callbacks get_intermediate() and target_intermediate(), only for drivers with target_index() and CPUFREQ_ASYNC_NOTIFICATION unset. get_intermediate() should return a stable intermediate frequency platform wants to switch to, and target_intermediate() should set CPU to that frequency, before jumping to the frequency corresponding to 'index'. Core will take care of sending notifications and driver doesn't have to handle them in target_intermediate() or target_index(). NOTE: ->target_index() should restore to policy->restore_freq in case of failures as core would send notifications for that. Tested-by: Stephen Warren <swarren@nvidia.com> Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org> Reviewed-by: Doug Anderson <dianders@chromium.org> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2014-04-30cpufreq: Introduce macros for cpufreq_frequency_table iterationStratos Karafotis
Many cpufreq drivers need to iterate over the cpufreq_frequency_table for various tasks. This patch introduces two macros which can be used for iteration over cpufreq_frequency_table keeping a common coding style across drivers: - cpufreq_for_each_entry: iterate over each entry of the table - cpufreq_for_each_valid_entry: iterate over each entry that contains a valid frequency. It should have no functional changes. Signed-off-by: Stratos Karafotis <stratosk@semaphore.gr> Acked-by: Lad, Prabhakar <prabhakar.csengg@gmail.com> Acked-by: Viresh Kumar <viresh.kumar@linaro.org> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2014-03-20cpufreq: Add stop CPU callback to cpufreq_driver interfaceDirk Brandewie
This callback allows the driver to do clean up before the CPU is completely down and its state cannot be modified. This is used by the intel_pstate driver to reduce the requested P state prior to the core going away. This is required because the requested P state of the offline core is used to select the package P state. This effectively sets the floor package P state to the requested P state on the offline core. Signed-off-by: Dirk Brandewie <dirk.j.brandewie@intel.com> [rjw: Minor modifications] Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2013-10-25cpufreq: Implement light weight ->target_index() routineViresh Kumar
Currently, the prototype of cpufreq_drivers target routines is: int target(struct cpufreq_policy *policy, unsigned int target_freq, unsigned int relation); And most of the drivers call cpufreq_frequency_table_target() to get a valid index of their frequency table which is closest to the target_freq. And they don't use target_freq and relation after that. So, it makes sense to just do this work in cpufreq core before calling cpufreq_frequency_table_target() and simply pass index instead. But this can be done only with drivers which expose their frequency table with cpufreq core. For others we need to stick with the old prototype of target() until those drivers are converted to expose frequency tables. This patch implements the new light weight prototype for target_index() routine. It looks like this: int target_index(struct cpufreq_policy *policy, unsigned int index); CPUFreq core will call cpufreq_frequency_table_target() before calling this routine and pass index to it. Because CPUFreq core now requires to call routines present in freq_table.c CONFIG_CPU_FREQ_TABLE must be enabled all the time. This also marks target() interface as deprecated. So, that new drivers avoid using it. And Documentation is updated accordingly. It also converts existing .target() to newly defined light weight .target_index() routine for many driver. Acked-by: Hans-Christian Egtvedt <egtvedt@samfundet.no> Acked-by: Jesper Nilsson <jesper.nilsson@axis.com> Acked-by: Linus Walleij <linus.walleij@linaro.org> Acked-by: Russell King <linux@arm.linux.org.uk> Acked-by: David S. Miller <davem@davemloft.net> Tested-by: Andrew Lunn <andrew@lunn.ch> Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org> Signed-off-by: Rafael J. Wysocki <rjw@rjwysocki.net>
2013-08-10cpufreq: Drop the owner field from struct cpufreq_driverViresh Kumar
We don't need to set .owner = THIS_MODULE any more in cpufreq drivers as this field isn't used any more by the cpufreq core. This patch removes it and updates all dependent drivers accordingly. Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org> 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>
2013-04-02cpufreq: drivers: Remove unnecessary assignments of policy-> membersViresh Kumar
Some assignments of policy-> min/max/cur/cpuinfo.min_freq/cpuinfo.max_freq aren't required as part of it is done by cpufreq driver or cpufreq core. Remove them. At some places we merge multiple lines together too. Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org> Acked-by: Sekhar Nori <nsekhar@ti.com> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2013-04-02cpufreq: Documentation: Fix cpufreq_frequency_table nameViresh Kumar
At few places in documentation cpufreq_frequency_table is written as cpufreq_freq_table. Fix these. Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2013-02-02cpufreq: Update Documentation for cpus and related_cpusViresh Kumar
Documentation related to cpus and related_cpus is confusing and not very clear. Over that CPUFreq core has seen much changes recently. Lets update documentation and comments for cpus and related_cpus. Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2011-06-13doc: fix wrong arch/i386 referencesWanlong Gao
Change all "arch/i386" to "arch/x86" in Documentaion/, since the directory has changed. Also update the files which have changed their filename in the meantime accordingly. Signed-off-by: Wanlong Gao <wanlong.gao@gmail.com> [jkosina@suse.cz: reword changelog] Signed-off-by: Jiri Kosina <jkosina@suse.cz>
2009-11-24[CPUFREQ] Document units for transition latencyMark Brown
They're documented in the header but not in Documentation. Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com> Signed-off-by: Dave Jones <davej@redhat.com>
2009-06-15[CPUFREQ] minor correction to cpu-freq documentationChumbalkar Nagananda
I have been reading the documentation for cpufreq closely. Found a couple of minor errors in the Documentation. Signed-off-by: Naga Chumbalkar <nagananda.chumbalkar@hp.com> Signed-off-by: Dave Jones <davej@redhat.com>
2005-04-16Linux-2.6.12-rc2Linus Torvalds
Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!