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path: root/drivers/devfreq/governor.h
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* PM / devfreq: passive: Keep cpufreq_policy for possible cpusChanwoo Choi2022-05-171-0/+3
| | | | | | | | | | The passive governor requires the cpu data to get the next target frequency of devfreq device if depending on cpu. In order to reduce the unnecessary memory data, keep cpufreq_policy data for possible cpus instead of NR_CPU. Tested-by: Chen-Yu Tsai <wenst@chromium.org> Tested-by: Johnson Wang <johnson.wang@mediatek.com> Signed-off-by: Chanwoo Choi <cw00.choi@samsung.com>
* PM / devfreq: Add cpu based scaling support to passive governorSaravana Kannan2022-05-171-0/+22
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Many CPU architectures have caches that can scale independent of the CPUs. Frequency scaling of the caches is necessary to make sure that the cache is not a performance bottleneck that leads to poor performance and power. The same idea applies for RAM/DDR. To achieve this, this patch adds support for cpu based scaling to the passive governor. This is accomplished by taking the current frequency of each CPU frequency domain and then adjust the frequency of the cache (or any devfreq device) based on the frequency of the CPUs. It listens to CPU frequency transition notifiers to keep itself up to date on the current CPU frequency. To decide the frequency of the device, the governor does one of the following: * Derives the optimal devfreq device opp from required-opps property of the parent cpu opp_table. * Scales the device frequency in proportion to the CPU frequency. So, if the CPUs are running at their max frequency, the device runs at its max frequency. If the CPUs are running at their min frequency, the device runs at its min frequency. It is interpolated for frequencies in between. Tested-by: Chen-Yu Tsai <wenst@chromium.org> Tested-by: Johnson Wang <johnson.wang@mediatek.com> Signed-off-by: Saravana Kannan <skannan@codeaurora.org> [Sibi: Integrated cpu-freqmap governor into passive_governor] Signed-off-by: Sibi Sankar <sibis@codeaurora.org> [Chanwoo: Fix conflict with latest code and cleanup code] Signed-off-by: Chanwoo Choi <cw00.choi@samsung.com>
* PM / devfreq: Export devfreq_get_freq_range symbol within devfreqChanwoo Choi2022-05-171-0/+2
| | | | | | | | | | In order to get frequency range within devfreq governors, export devfreq_get_freq_range symbol within devfreq. Reviewed-by: Matthias Kaehlcke <mka@chromium.org> Tested-by: Chen-Yu Tsai <wenst@chromium.org> Tested-by: Johnson Wang <johnson.wang@mediatek.com> Signed-off-by: Chanwoo Choi <cw00.choi@samsung.com>
* PM / devfreq: Add devm_devfreq_add_governor()Dmitry Osipenko2021-10-051-0/+3
| | | | | | | | Add resource-managed variant of devfreq_add_governor(). Signed-off-by: Dmitry Osipenko <digetx@gmail.com> Acked-by: Chanwoo Choi <cw00.choi@samsung.com> Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
* PM / devfreq: Remove the invalid description for get_target_freqDong Aisheng2021-04-081-2/+0
| | | | | | | | | | | | | First of all, no_central_polling was removed since commit 7e6fdd4bad03 ("PM / devfreq: Core updates to support devices which can idle") Secondly, get_target_freq() is not only called only with update_devfreq() notified by OPP now, but also min/max freq qos notifier. So remove this invalid description now to avoid confusing. Signed-off-by: Dong Aisheng <aisheng.dong@nxp.com> Signed-off-by: Chanwoo Choi <cw00.choi@samsung.com>
* PM / devfreq: Check get_dev_status in devfreq_update_statsDong Aisheng2021-04-081-0/+3
| | | | | | | | Check .get_dev_status() in devfreq_update_stats in case it's abused when a device does not provide it. Signed-off-by: Dong Aisheng <aisheng.dong@nxp.com> Signed-off-by: Chanwoo Choi <cw00.choi@samsung.com>
* PM / devfreq: Correct spelling in a commentLukasz Luba2021-01-051-1/+1
| | | | | | | | The device attribute exposed in sysfs is called 'polling_interval'. Align the comment. Signed-off-by: Lukasz Luba <lukasz.luba@arm.com> Signed-off-by: Chanwoo Choi <cw00.choi@samsung.com>
* PM / devfreq: Remove redundant governor_name from struct devfreqChanwoo Choi2020-10-261-0/+2
| | | | | | | | | | The devfreq structure instance contains the governor_name and a governor instance. When need to show the governor name, better to use the name of devfreq_governor structure. So, governor_name variable in struct devfreq is a redundant and unneeded variable. Remove the redundant governor_name of struct devfreq and then use the name of devfreq_governor instance. Signed-off-by: Chanwoo Choi <cw00.choi@samsung.com>
* PM / devfreq: Add governor attribute flag for specifc sysfs nodesChanwoo Choi2020-10-261-0/+12
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | DEVFREQ supports the default governors like performance, simple_ondemand and also allows the devfreq driver to add their own governor like tegra30-devfreq.c according to their requirement. In result, some sysfs attributes are useful or not useful. Prior to that the user can access all sysfs attributes regardless of the available attributes. So, clarify the access permission of sysfs attributes according to governor. When adding the devfreq governor, can specify the available attribute information by using DEVFREQ_GOV_ATTR_* constant variable. The user can read or write the sysfs attributes in accordance to the specified attributes. When adding the governor, can add the following attributes according to the governor feature. [Definition for speific sysfs attributes] - DEVFREQ_GOV_ATTR_POLLING_INTERVAL to update polling interval for timer. : /sys/class/devfreq/[devfreq dev name]/polling_interval - DEVFREQ_GOV_ATTR_TIMER to change the type of timer on either deferrable or dealyed timer. : /sys/class/devfreq/[devfreq dev name]/timer And all devfreq governors have to support the following common attributes. The common attributes are added to devfreq class by default. - governor - available_governors - available_frequencies - cur_freq - target_freq - min_freq - max_freq - trans_stat [Table of governor attribute flags for devfreq governors] ------------------------------------------------------------------------------ | simple | perfor | power | user | passive | tegra30 | ondemand | mance | save | space| | ------------------------------------------------------------------------------ governor | O | O | O | O | O | O available_governors | O | O | O | O | O | O available_frequencies | O | O | O | O | O | O cur_freq | O | O | O | O | O | O target_freq | O | O | O | O | O | O min_freq | O | O | O | O | O | O max_freq | O | O | O | O | O | O trans_stat | O | O | O | O | O | O -------------------------------------------------------- polling_interval | O | X | X | X | X | O timer | O | X | X | X | X | X ------------------------------------------------------------------------------ Reviewed-by: Dmitry Osipenko <digetx@gmail.com> Tested-by: Dmitry Osipenko <digetx@gmail.com> Signed-off-by: Chanwoo Choi <cw00.choi@samsung.com>
* PM / devfreq: Add governor feature flagChanwoo Choi2020-10-261-6/+12
| | | | | | | | | | | | | | | | | | | | | | | | | | | | The devfreq governor is able to have the specific flag as follows in order to implement the specific feature. For example, devfreq allows user to change the governors on runtime via sysfs interface. But, if devfreq device uses 'passive' governor, don't allow user to change the governor. For this case, define the DEVFREQ_GOV_FLAG_IMMUTABLE and set it to flag of passive governor. [Definition for governor flag] - DEVFREQ_GOV_FLAG_IMMUTABLE : If immutable flag is set, governor is never changeable to other governors. - DEVFREQ_GOV_FLAG_IRQ_DRIVEN : Devfreq core won't schedule polling work for this governor if value is set. [Table of governor flag for devfreq governors] ------------------------------------------------------------------------------ | simple | perfor | power | user | passive | tegra30 | ondemand | mance | save | space| | ------------------------------------------------------------------------------ immutable | X | X | X | X | O | O interrupt_driven | X(polling)| X | X | X | X | O (irq) ------------------------------------------------------------------------------ Reviewed-by: Dmitry Osipenko <digetx@gmail.com> Tested-by: Dmitry Osipenko <digetx@gmail.com> Signed-off-by: Chanwoo Choi <cw00.choi@samsung.com>
* PM / devfreq: Unify frequency change to devfreq_update_target funcChanwoo Choi2020-10-261-0/+1
| | | | | | | | | The update_devfreq() and update_passive_devfreq() have the duplicate code when changing the target frequency on final stage. So, unify frequency change code to devfreq_update_target() to remove the duplicate code and to centralize the frequency change code. Signed-off-by: Chanwoo Choi <cw00.choi@samsung.com>
* PM / devfreq: Fix a typo in a commentChristophe JAILLET2020-03-251-1/+1
| | | | | | | 'govenror' was used in place of 'governor' Signed-off-by: Christophe JAILLET <christophe.jaillet@wanadoo.fr> Signed-off-by: Chanwoo Choi <cw00.choi@samsung.com>
* PM / devfreq: Change to DEVFREQ_GOV_UPDATE_INTERVAL event nameChanwoo Choi2020-03-251-2/+2
| | | | | | | | | | | | | | | | DEVFREQ_GOV_INTERVAL event indicates that update the interval for polling mode of devfreq device. But, this event name doesn't specify exactly what to do. Change DEVFREQ_GOV_INTERVAL event name to DEVFREQ_GOV_UPDATE_INTERVAL which specifies what to do by event name. And modify the function name to DEVFREQ_GOV_UPDATE_INTERVAL with 'devfreq_' prefix + verb + object as following: - devfreq_interval_update -> devfreq_updatee_interval Reviewed-by: Lukasz Luba <lukasz.luba@arm.com> Signed-off-by: Chanwoo Choi <cw00.choi@samsung.com>
* PM / devfreq: Remove unneeded extern keywordChanwoo Choi2020-03-251-9/+8
| | | | | | | | | Remove unneeded extern keyword from devfreq-related header file and adjust the indentation of function parameter to keep the consistency in header file Reviewed-by: Lukasz Luba <lukasz.luba@arm.com> Signed-off-by: Chanwoo Choi <cw00.choi@samsung.com>
* PM / devfreq: Add new interrupt_driven flag for governorsDmitry Osipenko2019-11-061-0/+3
| | | | | | | | | | | | | | | Currently interrupt-driven governors (like NVIDIA Tegra30 ACTMON governor) are used to set polling_ms=0 in order to avoid periodic polling of device status by devfreq core. This means that polling interval can't be changed by userspace for such governors. The new governor flag allows interrupt-driven governors to convey that devfreq core shouldn't perform polling of device status and thus generic devfreq polling interval could be supported by these governors now. Signed-off-by: Dmitry Osipenko <digetx@gmail.com> Reviewed-by: Chanwoo Choi <cw00.choi@samsung.com> Signed-off-by: Chanwoo Choi <cw00.choi@samsung.com>
* treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 500Thomas Gleixner2019-06-191-4/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | Based on 2 normalized pattern(s): this program is free software you can redistribute it and or modify it under the terms of the gnu general public license version 2 as published by the free software foundation this program is free software you can redistribute it and or modify it under the terms of the gnu general public license version 2 as published by the free software foundation # extracted by the scancode license scanner the SPDX license identifier GPL-2.0-only has been chosen to replace the boilerplate/reference in 4122 file(s). Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Enrico Weigelt <info@metux.net> Reviewed-by: Kate Stewart <kstewart@linuxfoundation.org> Reviewed-by: Allison Randal <allison@lohutok.net> Cc: linux-spdx@vger.kernel.org Link: https://lkml.kernel.org/r/20190604081206.933168790@linutronix.de Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* PM / devfreq: Make update_devfreq() publicMatthias Kaehlcke2018-10-021-3/+0
| | | | | | | | | | | Currently update_devfreq() is only visible to devfreq governors outside of devfreq.c. Make it public to allow drivers that adjust devfreq policies to cause a re-evaluation of the frequency after a policy change. Signed-off-by: Matthias Kaehlcke <mka@chromium.org> Reviewed-by: Brian Norris <briannorris@chromium.org> Reviewed-by: Chanwoo Choi <cw00.choi@samsung.com> Signed-off-by: MyungJoo Ham <myungjoo.ham@samsung.com>
* PM / devfreq: Don't adjust to user limits in governorsMatthias Kaehlcke2018-10-021-0/+3
| | | | | | | | | | | | | Several governors use the user space limits df->min/max_freq to adjust the target frequency. This is not necessary, since update_devfreq() already takes care of this. Instead the governor can request the available min/max frequency by setting the target frequency to DEVFREQ_MIN/MAX_FREQ and let update_devfreq() take care of any adjustments. Signed-off-by: Matthias Kaehlcke <mka@chromium.org> Reviewed-by: Brian Norris <briannorris@chromium.org> Reviewed-by: Chanwoo Choi <cw00.choi@samsung.com> Signed-off-by: MyungJoo Ham <myungjoo.ham@samsung.com>
* PM / devfreq: Move private devfreq_update_stats() into devfreqChanwoo Choi2017-08-281-0/+4
| | | | | | | | | | | THe devfreq_update_stats() updates the 'struct devfreq_dev_status' in order to get current status of devfreq device. It is only used for the governors. This patch moves the devfreq_update_stats() into devfreq directory. Signed-off-by: Chanwoo Choi <cwchoi00@gmail.com> Signed-off-by: MyungJoo Ham <myungjoo.ham@samsung.com>
* PM / devfreq: Move struct devfreq_governor to devfreq directoryChanwoo Choi2017-04-121-0/+29
| | | | | | | | | This patch moves the struct devfreq_governor from header file to the devfreq directory because this structure is private data and it have to be only accessed by the devfreq core. Signed-off-by: Chanwoo Choi <cw00.choi@samsung.com> Signed-off-by: MyungJoo Ham <myungjoo.ham@samsung.com>
* PM / devfreq: Fix wrong trans_stat of passive devfreq deviceChanwoo Choi2017-01-311-0/+2
| | | | | | | | | | | Until now, the trans_stat information of passive devfreq is not updated. This patch updates the trans_stat information after setting the target frequency of passive devfreq device. Fixes: 996133119f57 ("PM / devfreq: Add new passive governor") Cc: stable@vger.kernel.org Signed-off-by: Chanwoo Choi <cw00.choi@samsung.com> Signed-off-by: MyungJoo Ham <myungjoo.ham@samsung.com>
* PM / devfreq: provide hooks for governors to be registeredNishanth Menon2012-11-201-0/+4
| | | | | | | | | | | | | | | | | | | 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>
* PM / devfreq: Add suspend and resume apisRajagopal Venkat2012-11-151-0/+2
| | | | | | | | | | 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>
* PM / devfreq: Core updates to support devices which can idleRajagopal Venkat2012-11-151-0/+11
| | | | | | | | | | | | | | | | | | | | | | | | | | | | 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>
* PM: Introduce devfreq: generic DVFS framework with device-specific OPPsMyungJoo Ham2011-10-021-0/+24
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>
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