Microchip USB Hub Driver Harmonization

[Richard Leitner]

Hello,
due to the fact (all?) the Microchip (former SMSC) USB hubs share the
same I2C configuration interface, I'm currently working on harmonizing
those USB Hub drivers. Currently this affects the usb251xb, usb3503 and
usb4604 drivers. To avoid preventable efforts (and patch versions) I
have some question on the preferred implementation:

1. Currently usb251xb uses i2c_smbus_*, usb3503 uses regmap_* and
usb4604 uses i2c_master_* functions for the hub configuration. What
would be the preferred solution?

2. What would be a good prefix for common headers/functions/macros/etc.?
I thought of "mcusbhub"... Would that be OK? Or are there any
conventions/better proposals on that?

3. Currently only usb3503 supports "platform data". Is this still needed
or may it be removed?

Thanks & kind regards,
RichardL