How to disable PMIC from powering up when USB cable is inserted.

[SKris]

Currently our custom board powers up in two cases, one when you press the power on button, and another when you plug in the USB cable.

We would like to disable PMIC from powering on when USB cable is plugged in. We see that the STPMIC specification document (section 5.4.2), lists the three conditions which triggers PMIC turn-on and also the register bit VBUSOTG_DET_DIS which needs to be set to 1 to disable this feature.

Since I cannot write to PMIC register address 0x40, was wondering if there is any device tree setting which sets this bit?

Any information on how to do this would be very much appreciated.

Thanks!

[Jean-Marc S]

Hello,

I may not have the full answer to your question.

However:

• the bit VBUSOTG_DET_DIS should do as you said (avoid power up of PMIC when USB is plugged)
• it should be set at each new power ON !! (since it is reset at 0 by default)

I am not sure why you said you cannot write into this register bit ?? PMIC registers should be available through I2C programming.

As for DT, I don't think anything is available to do this (I might be wrong...I could not find)

Hope this can provide some hints

JM