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i.MX Yocto Project: VBUSVALID and VDD5V Brownout configuration

Question asked by Damien Gotfroi on Aug 13, 2014



Can you please tell me, how and where can I configure VBUSVALID voltage and VDD5V Brownout voltage ?


I use Yocto with bitbake + Linux kernel 3.12.


I read the AP AN4199 "Using the i.MX28 Power Management Unit and Battery Charger", and it said :



The threshold value for a valid 5-V status is configured in the software, and the default value is 4.4 V on the Linux BSP. "




"VDD5V Brownout

The VDD5V-source

brownout level is a voltage threshold and is an absolute voltage value as in the case of a battery brownout.

There are four available settings for VBUS droop brownout:

• 4.3 V

• 4.4 V

• 4.5 V

• 4.7 V

Each setting has a 50-mV hysteresis to prevent chattering. It is set to 4.5 V in the Linux BSP "


But I would like to know in which file do i need to make the modifications and how ?


Many thanks in advance.