Linux: AM437x spread spectrum clocking

Eran Segal

Tool/software: Linux

Does anybody have an example of how to implement Spread Spectrum Clocking ( SSC) within the linux ( yocto ) not on u-boot

over 8 years ago

0 Biser Gatchev-XID over 8 years ago

TI__Guru**** 393215 points

What processor are you using?

0 Eran Segal over 8 years ago in reply to Biser Gatchev-XID

Prodigy 145 points

OMAP ARM Cortex-A9

Best Regards
Eran

0 Biser Gatchev-XID over 8 years ago in reply to Eran Segal

TI__Guru**** 393215 points

Sorry, OMAP devices are not supported on this forum.

0 Eran Segal over 8 years ago in reply to Eran Segal

Prodigy 145 points

Hi Biser,
Sorry! The processor is Sitara ARM Cortex-A9

Best Regards,
Eran

0 Eran Segal over 8 years ago in reply to Biser Gatchev-XID

Prodigy 145 points

Looking for how to implement Spread Spectrum Clocking ( SSC) under linux ( yocto ) not on u-boot
Sitara ARM Cortex-A9

Best Regards,
Eran

0 Biser Gatchev-XID over 8 years ago in reply to Eran Segal

TI__Guru**** 393215 points

Please check the AM437x TRM Rev. G, section 6.6.6. You will need to modify the Display and/or MPU PLL's initialization.

0 Eran Segal over 8 years ago in reply to Biser Gatchev-XID

Prodigy 145 points

I read section 6.6.6 and knew exactly what to do, but needed SW support where I should add under linux/driver ( yocto ) SSC extension.

Best Regards,
Eran

0 Pavel Botev over 8 years ago in reply to Eran Segal

TI__Guru**** 170625 points

Hi Eran,

AM437x Cortex-A9 MPU PLL is configured in the below linux kernel drivers:

linux-kernel/drivers/clk/ti/dpll.c
linux-kernel/drivers/clk/ti/clkt_dpll.c

linux-kernel/Documentation/devicetree/bindings/clock/ti/dpll.txt

Regards,
Pavel

Processors

Processors forum

Linux: AM437x spread spectrum clocking