net: phy: bcm84881: add BCM84891/BCM84892 support

Browse source

The BCM84891 and BCM84892 are 10GBASE-T PHYs in the same family as the
BCM84881, sharing the register map and most callbacks. They add USXGMII
as a host interface mode.

bcm8489x_config_init() is separate from bcm84881_config_init(): it
allows only USXGMII (the only host mode available on the tested
hardware) and clears MDIO_CTRL1_LPOWER, which is set at boot on the
tested platform. Does not recur on ifdown/ifup, cable events, or
link-partner advertisement changes, so config_init is sufficient.

For USXGMII, read_status() skips the 0x4011 host-mode register: it
returns the same value regardless of negotiated copper speed (USXGMII
symbol replication). Speed comes from phy_resolve_aneg_linkmode() via
standard C45 AN resolution.

Tested on TRENDnet TEG-S750 (RTL9303 + 1x BCM84891 + 4x BCM84892)
running OpenWrt, where the MDIO controller driver is currently
OpenWrt-specific. Link verified at 100M, 1G, 2.5G, 10G.

Signed-off-by: Daniel Wagner <wagner.daniel.t@gmail.com>
Reviewed-by: Florian Fainelli <florian.fainelli@broadcom.com>
Reviewed-by: Nicolai Buchwitz <nb@tipi-net.de>
Reviewed-by: Russell King (Oracle) <rmk+kernel@armlinux.org.uk>
Link: https://patch.msgid.link/20260330225310.2801264-1-wagner.daniel.t@gmail.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

...

This commit is contained in:

Daniel Wagner 2026-03-30 23:53:10 +01:00 • committed by Jakub Kicinski

parent e9abf1da0a

commit 75171eeff3

1 changed files with 47 additions and 1 deletions

Show all changes Ignore whitespace when comparing lines Ignore changes in amount of whitespace Ignore changes in whitespace at EOL

Download patch file Download diff file Expand all files Collapse all files

48

drivers/net/phy/bcm84881.c

View file