2 bool "Generic Dynamic Voltage and Frequency Scaling (DVFS) support"
6 A device may have a list of frequencies and voltages available.
7 devfreq, a generic DVFS framework can be registered for a device
8 in order to let the governor provided to devfreq choose an
9 operating frequency based on the device driver's policy.
11 Each device may have its own governor and policy. Devfreq can
12 reevaluate the device state periodically and/or based on the
13 notification to "nb", a notifier block, of devfreq.
15 Like some CPUs with CPUfreq, a device may have multiple clocks.
16 However, because the clock frequencies of a single device are
17 determined by the single device's state, an instance of devfreq
18 is attached to a single device and returns a "representative"
19 clock frequency of the device, which is also attached
20 to a device by 1-to-1. The device registering devfreq takes the
21 responsibility to "interpret" the representative frequency and
22 to set its every clock accordingly with the "target" callback
25 When OPP is used with the devfreq device, it is recommended to
26 register devfreq's nb to the OPP's notifier head. If OPP is
27 used with the devfreq device, you may use OPP helper
28 functions defined in devfreq.h.
32 comment "DEVFREQ Governors"
34 config DEVFREQ_GOV_SIMPLE_ONDEMAND
35 tristate "Simple Ondemand"
37 Chooses frequency based on the recent load on the device. Works
38 similar as ONDEMAND governor of CPUFREQ does. A device with
39 Simple-Ondemand should be able to provide busy/total counter
40 values that imply the usage rate. A device may provide tuned
41 values to the governor with data field at devfreq_add_device().
43 config DEVFREQ_GOV_PERFORMANCE
44 tristate "Performance"
46 Sets the frequency at the maximum available frequency.
47 This governor always returns UINT_MAX as frequency so that
48 the DEVFREQ framework returns the highest frequency available
51 config DEVFREQ_GOV_POWERSAVE
54 Sets the frequency at the minimum available frequency.
55 This governor always returns 0 as frequency so that
56 the DEVFREQ framework returns the lowest frequency available
59 config DEVFREQ_GOV_USERSPACE
62 Sets the frequency at the user specified one.
63 This governor returns the user configured frequency if there
64 has been an input to /sys/devices/.../power/devfreq_set_freq.
65 Otherwise, the governor does not change the frequency
66 given at the initialization.
68 config DEVFREQ_GOV_PASSIVE
71 Sets the frequency based on the frequency of its parent devfreq
72 device. This governor does not change the frequency by itself
73 through sysfs entries. The passive governor recommends that
74 devfreq device uses the OPP table to get the frequency/voltage.
76 comment "DEVFREQ Drivers"
78 config ARM_EXYNOS_BUS_DEVFREQ
79 tristate "ARM EXYNOS Generic Memory Bus DEVFREQ Driver"
80 depends on ARCH_EXYNOS || COMPILE_TEST
81 select DEVFREQ_GOV_SIMPLE_ONDEMAND
82 select DEVFREQ_GOV_PASSIVE
83 select DEVFREQ_EVENT_EXYNOS_PPMU
84 select PM_DEVFREQ_EVENT
87 This adds the common DEVFREQ driver for Exynos Memory bus. Exynos
88 Memory bus has one more group of memory bus (e.g, MIF and INT block).
89 Each memory bus group could contain many memoby bus block. It reads
90 PPMU counters of memory controllers by using DEVFREQ-event device
91 and adjusts the operating frequencies and voltages with OPP support.
92 This does not yet operate with optimal voltages.
94 config ARM_TEGRA_DEVFREQ
95 tristate "Tegra DEVFREQ Driver"
96 depends on ARCH_TEGRA_124_SOC
97 select DEVFREQ_GOV_SIMPLE_ONDEMAND
100 This adds the DEVFREQ driver for the Tegra family of SoCs.
101 It reads ACTMON counters of memory controllers and adjusts the
102 operating frequencies and voltages with OPP support.
104 config ARM_RK3399_DMC_DEVFREQ
105 tristate "ARM RK3399 DMC DEVFREQ Driver"
106 depends on ARCH_ROCKCHIP
107 select DEVFREQ_EVENT_ROCKCHIP_DFI
108 select DEVFREQ_GOV_SIMPLE_ONDEMAND
109 select PM_DEVFREQ_EVENT
112 This adds the DEVFREQ driver for the RK3399 DMC(Dynamic Memory Controller).
113 It sets the frequency for the memory controller and reads the usage counts
116 source "drivers/devfreq/event/Kconfig"