[beagleboard] Configuring clock frequency

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1

Hi,

How can I configure the clock frequency of arm cortex A8 on beagleboard.
I could not find any configuration while building the kernel to do this .

2

Guys, can anyone please give some inputs on this .

3

It should be in include/asm-arm/arch-omap3/clocks_omap3.h (u-boot sources)

4

Hi,

How can I configure the clock frequency of arm cortex A8 on beagleboard.
I could not find any configuration while building the kernel to do this .

In menuconfig, look for
SYSTEM TYPE → ENABLE TI OMAP POWER MANAGEMENT → VDD1 OPP
Here we have option to select different OPP/ OMAP MPU frequency.

Regards,
Shankar

5

Hi Shankar Ganesh,

I had used that but the mips still showed as 549.xx . It means that it is still running at 550 mhz right ?
Please correct me if I am wrong, How can I verify the speed after choosing the option.

6

"BogoMips (from "bogus" and MIPS) is an unscientific measurement" - it's not saying anything at all

7

ok,
But How can I check the processor clock frequency from userspace ?

8

Hi Shankar Ganesh,

I had used that but the mips still showed as 549.xx . It means that it is still running at 550 mhz right ?
Please correct me if I am wrong, How can I verify the speed after choosing the option.

Also refer to /kernel/arch/arm/mach-omap2/clock_34xx.c / .h

Here bogoMIPS = loops per jiffy * No of jiffies in 1 sec * No of million Instruction consumed in delay loop [/init/calibrate.c]

-shankar

9

Thanks for the help , I managed to reduce the clock frequency by changing the prcm configuration while the kernel is booting .

10

Hello,
Is possible to change the clock frequency during the normal system
operation, whithout having to reboot it? Or there is any way to reduce
de power consumption for a while, mantaining the system up and
working?
Thank you.