From: Linus Walleij <redacted>
Date: Sat, 30 Jun 2018 13:17:30 +0200

The VSC7385, VSC7388, VSC7395 and VSC7398 are integrated
switch/router chips for 5+1 or 8-port switches/routers. When
managed directly by Linux using DSA we need to do a special
set-up "dance" on the PHY. Unfortunately these sequences
switches the PHY to undocumented pages named 2a30 and 52b6
and does undocumented things. It is described by these opaque
sequences also in the reference manual. This is a best
effort to integrate it anyways.

Reviewed-by: Florian Fainelli <f.fainelli@gmail.com>
Signed-off-by: Linus Walleij <redacted>
---
ChangeLog v1->v2:
- Drop <linux/delay.h> from an earlier iteration.
- Implement an .config_aneg() routine that does nothing: the
  imroved genphy_config_aneg() makes the device fail as of
  v4.18-rc1 and the device seems to feel best like this: it
  comes up in autonegotiation mode and we do not try to instruct
  it.
- Use some MII defines when reading/writing registers.
- Collect Florian's ACK.

Applied.