Description

Control CPU scaling governer.

Functions to read and set the current CPU scaling function. This is not specific to the beaglebone and should work on any linux system, however since the beaglebone has a single cpu core, this only changes the govenor for one core.

Author: James Strawson

Date: 3/7/2018

Typedefs
typedef enum rc_governor_t	rc_governor_t

Functions
int	rc_cpu_set_governor (rc_governor_t gov)
	Sets the CPU governor. See rc_governor_t. More...

int	rc_cpu_get_freq (void)
	Returns the current clock speed of the Beaglebone's Sitara processor in the form of the provided enumerated type. It will never return the FREQ_ONDEMAND value as the intention of this function is to see the clock speed as set by either the user or the ondemand governor itself. More...

int	rc_cpu_print_freq (void)
	Prints the current frequency to the screen. For example "600mhz". More...

Enumeration Type Documentation

◆ rc_governor_t

enum rc_governor_t

available CPU governors

Enumerator
RC_GOV_POWERSAVE	Sets CPU to slowest speed.
RC_GOV_PERFORMANCE	Sets CPU to fastest speed.
RC_GOV_ONDEMAND	Default automatic scaling.
RC_GOV_SCHEDUTIL	Like ONDEMAND but newer algorithm.
RC_GOV_CONSERVATIVE	Automatically scales the cpu but still tries to save power.

Function Documentation

◆ rc_cpu_set_governor()

int rc_cpu_set_governor ( rc_governor_t gov )

Sets the CPU governor. See rc_governor_t.

This is the equivalent to running 'cpufreq-set -g {governor}' from the command line but can be called in your C program instead.

Parameters

[in] gov Desired governor

Returns: 0 on success, -1 on failure.

Examples:: rc_cpu.c.

◆ rc_cpu_get_freq()

int rc_cpu_get_freq ( void )

Returns the current clock speed of the Beaglebone's Sitara processor in the form of the provided enumerated type. It will never return the FREQ_ONDEMAND value as the intention of this function is to see the clock speed as set by either the user or the ondemand governor itself.

Returns: frequency in hz

◆ rc_cpu_print_freq()

int rc_cpu_print_freq ( void )

Prints the current frequency to the screen. For example "600mhz".

Returns: 0 on success or -1 on failure.

Examples:: rc_cpu.c.