[Bug ?] usb :typec :tcpm :fusb302

From: Markus Reichl
Date: Thu Jan 09 2020 - 11:29:14 EST


Hi,

I'm working with a ROC-RK3399-PC arm64 board from firefly, circuit sheet [1].
The board is powered from an USB-C type connector via an FUSB302 PD controller.
With measured 15W+ power consumption it should use higher voltage PD modes than
the standard 5V USB-C mode.

When I add the related connector node in DTS [2] the FUSB302 initializes
the right PD mode (e.g. 15V/3A).

But during initialisation the PD is switched off shortly and the board has a blackout.
When I inject a backup supply voltage behind the FUSB302 (e.g. at SYS_12V line) during boot
I can remove the backup after succesfull setting up the PD and the board will run fine.

Is it possible to change the behaviour of the fusb302 driver to not power down the PD supply
during init?

In vendor kernel (4.4) this is done somehow but the sources are too different for me to find
out how.

GruÃ,
--
Markus Reichl

[1]
http://download.t-firefly.com/product/RK3399/Docs/Hardware/%E5%8E%9F%E7%90%86%E5%9B%BE%E5%92%8C%E8%B4%B4%E7%89%87%E5%9B%BE/ROC-RK3399-PC/ROC-3399-PC-V10-A-20180804_%E5%8E%9F%E7%90%86%E5%9B%BE.pdf

[2]
https://lkml.org/lkml/2019/12/10/517