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linux/drivers/devfreq/Makefile

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PM: Introduce devfreq: generic DVFS framework with device-specific OPPs 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>
2011-10-02 00:19:15 +02:00
obj-$(CONFIG_PM_DEVFREQ) += devfreq.o
PM / devfreq: Add basic governors Four cpufreq-like governors are provided as examples. powersave: use the lowest frequency possible. The user (device) should set the polling_ms as 0 because polling is useless for this governor. performance: use the highest freqeuncy possible. The user (device) should set the polling_ms as 0 because polling is useless for this governor. userspace: use the user specified frequency stored at devfreq.user_set_freq. With sysfs support in the following patch, a user may set the value with the sysfs interface. simple_ondemand: simplified version of cpufreq's ondemand governor. When a user updates OPP entries (enable/disable/add), OPP framework automatically notifies devfreq to update operating frequency accordingly. Thus, devfreq users (device drivers) do not need to update devfreq manually with OPP entry updates or set polling_ms for powersave , performance, userspace, or any other "static" governors. Note that these are given only as basic examples for governors and any devices with devfreq may implement their own governors with the drivers and use them. Signed-off-by: MyungJoo Ham <myungjoo.ham@samsung.com> Signed-off-by: Kyungmin Park <kyungmin.park@samsung.com> Reviewed-by: Mike Turquette <mturquette@ti.com> Acked-by: Kevin Hilman <khilman@ti.com> Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
2011-10-02 00:19:34 +02:00
obj-$(CONFIG_DEVFREQ_GOV_SIMPLE_ONDEMAND) += governor_simpleondemand.o
obj-$(CONFIG_DEVFREQ_GOV_PERFORMANCE) += governor_performance.o
obj-$(CONFIG_DEVFREQ_GOV_POWERSAVE) += governor_powersave.o
obj-$(CONFIG_DEVFREQ_GOV_USERSPACE) += governor_userspace.o
PM/Devfreq: Add Exynos4-bus device DVFS driver for Exynos4210/4212/4412. Exynos4-bus device devfreq driver add DVFS capability for Exynos4210/4212/4412-Bus (memory). The driver monitors PPMU counters of memory controllers and adjusts operating frequencies and voltages with OPP. For Exynos4210, vdd_int is controlled. For exynos4412/4212, vdd_mif and vdd_int are controlled. Dependency (CONFIG_EXYNOS_ASV): Exynos4 ASV driver has been posted in the mailing list; however, it si not yet upstreamed. Although the current revision of Exynos4 ASV patch does not contain "CONFIG_EXYNOS_ASV", we have added the symbol to hide the dependent from compilers for now. As soon as Exynos4 ASV drivers are merged, the #ifdef statement will be removed or the name will be changed. However, enabling ASV is essential in most Exynos4 chips to reduce the power consumption of Exynos4210 because without ASV, this Devfreq driver assumes the worst case scenario, which consumes more power. Signed-off-by: MyungJoo Ham <myungjoo.ham@samsung.com> Signed-off-by: Kyungmin Park <kyungmin.park@samsung.com> --- Changes from v1 - Support 4212 and 4412 as well as 4210.
2011-07-14 10:33:55 +09:00
# DEVFREQ Drivers
obj-$(CONFIG_ARM_EXYNOS4_BUS_DEVFREQ) += exynos4_bus.o
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