Power ManagementのトピックRe: DTS to support NDM and LDM modes

DTS to support NDM and LDM modes

OlivierG — Thu, 23 Jan 2025 10:26:18 GMT

I have a "imk93 11x11 EVK" card
on Yocto , i have done the following commands

# echo 1 > /sys/devices/platform/imx93-lpm/mode
# cat /sys/devices/platform/imx93-lpm/mode
System is in ND mode with DDR 1866 MTS!
# mhz
1398 MHz, 0.7153 nanosec clock

# echo 0 > /sys/devices/platform/imx93-lpm/mode
# mhz
1690 MHz, 0.5917 nanosec clock

Unfortunatelly echo 2 and echo 3 dosn't work

i have to change nodes in the dts tree to add these 2 modes

Where ares the dst files i have to change ?
Where ares the nodes i have to change in the dst files ?

greetings

Re: DTS to support NDM and LDM modes

Chavira — Thu, 23 Jan 2025 14:01:17 GMT

HI @OlivierG!

Thank you for contacting NXP Support!

To use the full LP Modes you have to use the imx93-11x11-evk-ld.dtb instead of imx93-11x11-evk.dtb.

Please update the device tree and you should be able to use all the modes.

Best Regards!

Chavira

Re: DTS to support NDM and LDM modes

OlivierG — Thu, 23 Jan 2025 15:26:59 GMT

Its works Thanks

i have another question

On some card Yocto mounts the following directory :

/sys/devices/system/cpu/cpu0/cpufreq

this directory is not mounted on imx93 (cpufreq is missing)

i imagine that the hardware doesn't permit to modify the frequencies directely

Greetings

Re: DTS to support NDM and LDM modes

Chavira — Thu, 23 Jan 2025 15:43:02 GMT

Hi @OlivierG!

In iMX93 the CPU and DDR frequencies are managed by LPM module.

You can use the command mhz instead

Re: DTS to support NDM and LDM modes

OlivierG — Tue, 28 Jan 2025 13:36:44 GMT

Is there a way to change the CPU and DDR frequencies associated to the LPM modes ? In DTS files ?

It,s for a bench and i need to set theses parameters independently

Greetings

Re: DTS to support NDM and LDM modes

Chavira — Wed, 29 Jan 2025 16:43:12 GMT

Hi @OlivierG!

That is not possible, maybe you can modify the lpm driver but I recommend to maintain the drivers without modifications.