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path: root/drivers/devfreq/governor.h
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2018-10-02PM / devfreq: Make update_devfreq() publicMatthias Kaehlcke1-3/+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>
2018-10-02PM / devfreq: Don't adjust to user limits in governorsMatthias Kaehlcke1-0/+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>
2017-08-28PM / devfreq: Move private devfreq_update_stats() into devfreqChanwoo Choi1-0/+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>
2017-04-12PM / devfreq: Move struct devfreq_governor to devfreq directoryChanwoo Choi1-0/+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>
2017-01-31PM / devfreq: Fix wrong trans_stat of passive devfreq deviceChanwoo Choi1-0/+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>
2012-11-20PM / devfreq: provide hooks for governors to be registeredNishanth Menon1-0/+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>
2012-11-15PM / devfreq: Add suspend and resume apisRajagopal Venkat1-0/+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>
2012-11-15PM / devfreq: Core updates to support devices which can idleRajagopal Venkat1-0/+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>
2011-10-02PM: Introduce devfreq: generic DVFS framework with device-specific OPPsMyungJoo Ham1-0/+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>