AM69A: PLL Configuration in U-boot

Emily Kinne

Part Number: AM69A

Tool/software:

Hello TI we followed section 5.4.8.10.2 Entire Sequence for Programming PLLCTRL in the TRM to disable some of the PLL clocks we are not using. I used the k3conf write command to unlock and write to the registers. I was wondering if I can make these same changes in U-boot so the clocks are disabled before the processor boots into Linux?

Thank you,
Emily

1 month ago

0 Keerthy J 1 month ago

TI__Guru*** 145090 points

Emily,

U-Boot does not have any tool parallel to k3conf. What exactly do you want to disable? More details can help us explore if we can disable from U-Boot.

Best regards,

Keerthy

0 Emily Kinne 1 month ago in reply to Keerthy J

Prodigy 185 points

We want to disabled MAIN PLLs we do not use to reduce power. Such as PLL6_GPU, PLL25_Vision, PLL27_DDR2, PLL28_DDR3, etc.
As well as reduce the clock frequency of DEV_COMPUTE_CLUSTER0_C71SS0_CORE0_C7X_CLK

Emily

0 Keerthy J 1 month ago in reply to Emily Kinne

TI__Guru*** 145090 points

Hi Emily,

If you were using k3conf to directly write to registers then U-Boot does have the md/mw commands to memory dump and memory write.

https://www.google.com/url?sa=t&source=web&rct=j&opi=89978449&url=https://github.com/u-boot/u-boot/blob/master/README&ved=2ahUKEwiiy97phYWIAxWS3jgGHYmoBIkQFnoECCUQAQ&usg=AOvVaw1KKBCplb-_K-ua9tzfll4Y

Regards,

Keerthy

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AM69A: PLL Configuration in U-boot