Root/drivers/devfreq/Kconfig

1menuconfig PM_DEVFREQ
2    bool "Generic Dynamic Voltage and Frequency Scaling (DVFS) support"
3    help
4      A device may have a list of frequencies and voltages available.
5      devfreq, a generic DVFS framework can be registered for a device
6      in order to let the governor provided to devfreq choose an
7      operating frequency based on the device driver's policy.
8
9      Each device may have its own governor and policy. Devfreq can
10      reevaluate the device state periodically and/or based on the
11      notification to "nb", a notifier block, of devfreq.
12
13      Like some CPUs with CPUfreq, a device may have multiple clocks.
14      However, because the clock frequencies of a single device are
15      determined by the single device's state, an instance of devfreq
16      is attached to a single device and returns a "representative"
17      clock frequency of the device, which is also attached
18      to a device by 1-to-1. The device registering devfreq takes the
19      responsibility to "interpret" the representative frequency and
20      to set its every clock accordingly with the "target" callback
21      given to devfreq.
22
23      When OPP is used with the devfreq device, it is recommended to
24      register devfreq's nb to the OPP's notifier head. If OPP is
25      used with the devfreq device, you may use OPP helper
26      functions defined in devfreq.h.
27
28if PM_DEVFREQ
29
30comment "DEVFREQ Governors"
31
32config DEVFREQ_GOV_SIMPLE_ONDEMAND
33    tristate "Simple Ondemand"
34    help
35      Chooses frequency based on the recent load on the device. Works
36      similar as ONDEMAND governor of CPUFREQ does. A device with
37      Simple-Ondemand should be able to provide busy/total counter
38      values that imply the usage rate. A device may provide tuned
39      values to the governor with data field at devfreq_add_device().
40
41config DEVFREQ_GOV_PERFORMANCE
42    tristate "Performance"
43    help
44      Sets the frequency at the maximum available frequency.
45      This governor always returns UINT_MAX as frequency so that
46      the DEVFREQ framework returns the highest frequency available
47      at any time.
48
49config DEVFREQ_GOV_POWERSAVE
50    tristate "Powersave"
51    help
52      Sets the frequency at the minimum available frequency.
53      This governor always returns 0 as frequency so that
54      the DEVFREQ framework returns the lowest frequency available
55      at any time.
56
57config DEVFREQ_GOV_USERSPACE
58    tristate "Userspace"
59    help
60      Sets the frequency at the user specified one.
61      This governor returns the user configured frequency if there
62      has been an input to /sys/devices/.../power/devfreq_set_freq.
63      Otherwise, the governor does not change the frequnecy
64      given at the initialization.
65
66comment "DEVFREQ Drivers"
67
68config ARM_EXYNOS4_BUS_DEVFREQ
69    bool "ARM Exynos4210/4212/4412 Memory Bus DEVFREQ Driver"
70    depends on CPU_EXYNOS4210 || SOC_EXYNOS4212 || SOC_EXYNOS4412
71    select ARCH_HAS_OPP
72    select DEVFREQ_GOV_SIMPLE_ONDEMAND
73    help
74      This adds the DEVFREQ driver for Exynos4210 memory bus (vdd_int)
75      and Exynos4212/4412 memory interface and bus (vdd_mif + vdd_int).
76      It reads PPMU counters of memory controllers and adjusts
77      the operating frequencies and voltages with OPP support.
78      To operate with optimal voltages, ASV support is required
79      (CONFIG_EXYNOS_ASV).
80
81config ARM_EXYNOS5_BUS_DEVFREQ
82    bool "ARM Exynos5250 Bus DEVFREQ Driver"
83    depends on SOC_EXYNOS5250
84    select ARCH_HAS_OPP
85    select DEVFREQ_GOV_SIMPLE_ONDEMAND
86    help
87      This adds the DEVFREQ driver for Exynos5250 bus interface (vdd_int).
88      It reads PPMU counters of memory controllers and adjusts the
89      operating frequencies and voltages with OPP support.
90
91endif # PM_DEVFREQ
92

Archive Download this file



interactive