iMX8QM - POWER_ENABLE_MOCI and RESET_MOCI access from userspace

[ml_man]

Hello,

I’m using Apalis IMX8QM on custom carrier board.

I’ve set this topic to confirm my assumption - is it possible to get access to pins POWER_ENABLE_MOCI and RESET_MOCI of IMX from user space?

I’ve read the below topic,

Can POWER_ENABLE_MOCI be deasserted upon request on iMX8QM?

I would like to deassert POWER_ENABLE_MOCI before going into sleep mode on my apalis iMX8QM to save additional power on my custom board. Is this possible? Would it require a PMIC firmware change? On a future board-spin, I can use a GPIO and gate the peripheral power lines externally to the SOM, but I have existing boards in the field where this is not possible. Is there anyway to turn off the peripheral power rails during sleep-mode?

but in my case I’d like to control if the peripherals are enabled or not, or reset them, when the system is running. Is it possible? Or the only way is to use normal GPIO which is connected to power control of peripherals?

I will be grateful for answer,
Best Regards,
Michal

[matthias.tx]

Hello @ml_man,

Yes you have to use a GPIO for that. The POWER_ENABLE_MOCI signal is a signal that is not generated by the SOC.

Best Regards,

Matthias

[alex.tx]

Though theoretically it is possible to control POWER_ENABLE_MOCI and probably RESET_MOCI signals by hacking the PMIC, such a hack would completely break the functionality of the module.
If you wish to control the enabling or resetting of peripherals while the system is running, you can design your carrier board to include GPIO lines that allow for such control.

[ml_man]

Thank you for your reply and dispel the doubts.

Best Regards,
Michael