USB Vbus drop in OTG mode on iMX8QM

[fmonte]

Hello,

on iMX8Qm when I set the USB port to OTG mode (by setting the USB_OTG2_ID pad) the power enable pad (SS3_TC0) voltage drops, causing in a drop of the Vbus on the OTG port.

This is actually correct by reading the OTG specification. However, is it possible to control the SS3_TC0/USB_OTG1_PWR signal, regardless of the OTG/host status?

Thank you!

Francesco

[igorpadykov]

Hi Francesco

seems one can reconfigure SS3_TC0 as GPIO4_IO03 and make

necessary modifications in driver.

Best regards
igor

[fmonte]

Hi Igor,

I know that muxing to GPIO is a possible solution. However, we cannot do that since in SCU FW port the GPIO4 device is assigned to a reserved HW partition.

Is it possible to keep the Vbus in OTG mode by reconfiguring some register?

[igorpadykov · Accepted solution]

Hi Francesco

>Is it possible to keep the Vbus in OTG mode by reconfiguring some register?

not.

Best regards
igor

[igorpadykov · Accepted solution]

Hi Francesco

>Is it possible to keep the Vbus in OTG mode by reconfiguring some register?

[igorpadykov · Accepted solution]

not.

Best regards
igor