[PATCH net-next 0/4] RGMII mode clarification + am65-cpsw fix

[Matthias Schiffer <matthias.schiffer@ew.tq-group.com>]

As discussed [1], the comments for the different rgmii(-*id) modes do not
accurately describe what these values mean. Update the binding
documentation and fix up the mode to account for the fixed TX delay on
the AM65 CPSW Ethernet controllers, similar to the way the icssg-prueth
does it. For backwards compatibility, the "impossible" modes that claim
to have a delay on the PCB are still accepted, but trigger a warning
message.

As Andrew suggested, I have also added a checkpatch check that requires
a comment for any RGMII mode that is not "rgmii-id".

No Device Trees are updated to avoid the warning for now, to give other
projects syncing the Linux Device Trees some time to fix their drivers
as well. I intend to submit an equivalent change for U-Boot's
am65-cpsw-nuss driver as soon as the changes are accepted for Linux.

[1] https://lore.kernel.org/lkml/d25b1447-c28b-4998-b238-92672434dc28@lunn.ch/

Submitting for net-next for now - I don't know it would make sense to
backport some of these changes to stable.

Note: I have also added the maintainers for the TI K3 SoC families to cc
in addition to the get_maintainers.pl output, to loop in some more of
the relevant people at TI. Should MAINTAINERS be extended to include
some of you for the am65-cpsw* files? At the moment, only the netdev
maintainers are reported for drivers/net/ethernet/ti/am65-cpsw-nuss.c
(except for "authored" lines etc.)

Matthias Schiffer (4):
  dt-bindings: net: ethernet-controller: update descriptions of RGMII
    modes
  dt-bindings: net: ti: k3-am654-cpsw-nuss: update phy-mode in example
  net: ethernet: ti: am65-cpsw: fixup PHY mode for fixed RGMII TX delay
  checkpatch: check for comment explaining rgmii(|-rxid|-txid) PHY modes

 Documentation/dev-tools/checkpatch.rst        |  9 +++++++
 .../bindings/net/ethernet-controller.yaml     | 16 ++++++-----
 .../bindings/net/ti,k3-am654-cpsw-nuss.yaml   |  2 +-
 drivers/net/ethernet/ti/am65-cpsw-nuss.c      | 27 +++++++++++++++++--
 scripts/checkpatch.pl                         | 11 ++++++++
 5 files changed, 55 insertions(+), 10 deletions(-)

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