OMAP5432 DVFS / cpufreq not available

Connor Imes

Good afternoon.

I'm working with an OMAP5432, running Ubuntu 12.04.4 with kernel 3.8.4-100-omap5 from the TI release PPA [1].

[1] https://launchpad.net/~tiomap-dev/+archive/release

I need a kernel that allows frequency scaling. When I run cpufreq-info, I get

no or unknown cpufreq driver is active on this CPU

for both CPU0 and CPU1. I suspect I need a newer modified kernel but have not been able to find one for this architecture and have struggled to get one to build properly. Trying to install a newer kernel (e.g. from Ubuntu Trusty development) gets me an error like

/boot/vmlinuz-3.13.0-14-generic does not match your subarchitecture omap5, therefore not writing to flash.

If anybody knows how I can get cpufreq support, that would be great. Thanks.

over 12 years ago

0 Yanko Todorov-XID over 12 years ago

TI__Mastermind 29520 points

Hello Imes,

I suggest using omapconf tool available in OMAP5 GLSDK.

By using this tool you can obtain information about CPUFreq. I want to notice that CPU frequency depends on the OPP settings.

To change CPU frequency dynamically you must enable AVS modules in OMAP5. See section SmartReflex Module Initialization in OMAP5 TRM. To enable SMARTREFLEX_MPU you must set bit - SRCONFIG[11] SRENABLE - 0x1.

Capture CPUs Load, MPU/GPU/L3 OPP Changes, EMIF data bus load, temperatures (ondie sensors,
PCB, CASE) over time. - Use the command - omapconf trace perf

See the omapconf user guide: https://github.com/omapconf/omapconf/wiki

You can see CPUFreq implementation in board-support/linux/arch/arm/mach-omap2/omap-pm-noop.c and in drivers/cpufreq/ in OMAP5 GLSDK.

Best regards,

Yanko

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OMAP5432 DVFS / cpufreq not available