On Sun, Oct 4, 2020 at 8:00 PM Martin Blumenstingl
[off-list ref] wrote:

The goal of this series to add support for the GPIO controller on the
Etron EJ168/EJ188/EJ198 controllers.

This overall is a fine driver, but have you considered the option of just
implementing the GPIO chip in drivers/usb/host/xhci-pci.c?

There are several USB serial adapters that have a GPIO chip
embedded and we just add the GPIO chip into the serial driver.
I have done the same with some networking switches. It is
perfectly fine for drivers outside of drivers/gpio to occasionally
define a minor GPIO chip if GPIO is not their primary function.

Please consider simply activating the XHCI driver and make it
instantiate a GPIO chip if it happens to be an
EJ168/EJ188/EJ198 controller.

Yours,
Linus Walleij