Poweroff USB port from userland

[gnulux]

Hi all , 

I'm working on development of a new board that will host IMXMP SOC. 

I would like someway to poweroff usb port or usb devices from a program in linux userland. 

Can i do this with the IMX processor ? does PMIC (regulator chip)  can manage that ? 

thks

[gnulux]

Hi, 

Mainly Host port.

On my final board ( which will have a little power rescue) i will have on USB port :

    - a NFC reader

    - backlight for touchscreen

    - BLE

    - Camera .

At the end, i would like to poweroff all usb port when main power supply is off except for the backlight.

I plan to use a SMARC 2.1 card with a IMX8MP this card has 6 USB ports + 1 OTG available.

I was wondering if if it was possible ?

[Zhiming_Liu]

Hi

For HOST port, you can control USB2_PWR_EN to close USB2_HOST_VBUS if you reserve this part from EVK.

[Zhiming_Liu]

Hi @gnulux 

PMIC can't do this, please refer kernel document:

https://www.kernel.org/doc/html/latest/driver-api/usb/power-management.html

[gnulux]

Thks for your reply .
I'd already read and tested usbpower management , but it appears that usb devices still consume few watts in suspend.

I really need to cut the power to reduce power consumption.

[Zhiming_Liu]

Hi

Can you share which usb port you need manage power, HOST port  or TYPEC port?