What is the low power mode microcontroller on the FX30?


#1

Is the low power microcontroller a separate controller dedicated to low power mode or is it built into the WP module?

If it is a separate controller, who makes it and what model is it?

Are there any diagrams available for how this is wired into the rest of the FX30?

I’m getting the low power mode info from this document: https://source.sierrawireless.com/resources/airlink/hardware_reference_docs/airlink_fx30_hw_user_guide/


#2

I see some mention of Qualcomm’s PM8018 in “/sys/devices/platform/msm_ssbi.0/”. Is this the PMIC the user guide refers to as “the low power micro-controller”?


#3

Hi @jrm06c,

The PMIC is a separate controller internal to the WP module.
There are no diagrams as of yet, is there any particular information you need?

BR,
Chris


#4

I’m wondering if the PMIC (and/or WP firmware) can be reprogrammed to trigger on different GPIO. Specifically, I’m wanting to trigger on GPIO42 which is the IoT Connector’s (expansion slot) GPIO1. I’m using a CAN IoT card that can sleep and wake on CAN bus traffic. It sends an interrupt signal to GPIO42 when it wakes. I’d like to wake the FX30 when there’s CAN bus activity.

I see the spec here
https://source.sierrawireless.com/resources/airprime/hardware_specs_user_guides/airprime_wp75xx_wp8548_product_technical_specification/
says GPIO42 can only be used as a trigger from USB-SS power mode. Is this absolutely the case or can it be done with special firmware? Are these GPIOs hardwired from the MDM8215 to the PMIC? Are there others that aren’t doucmented? I see GPIO39 seems to be available but isn’t documented.


#5

Hi @rkirk,
Would you be able to comment on this?
Thanks,
Chris


#6

Hi @jrm06c,

Unfortunately the GPIO inputs to the ULPM monitoring system are physically limited to the documented set, and can’t be extended by software. The ULPM micro is actually not the Qualcomm PMIC referenced above, but the same logic applies - the physical mapping of the GPIO is the limitation that prevents GPIO42 or other pins not connected to the ULPM micro from waking up the system from ULPM.

Not the answer you were hoping for, but let me know if that doesn’t answer your question.

Regards,
Ryan


#7

That makes the original question moot, thanks.