[RFC PATCH 0/6] Add ethernet support for the Amlogic T7

[Lucas Tanure <tanure@linux.com>]

The T7 pairs a Synopsys gigabit MAC with the same glue registers the
G12A has, but nothing described it, so the port could not be used.

This adds the binding, the driver support and the device tree nodes, and
enables the port on the Khadas VIM4, which has an external RTL8211F over
RGMII.

What is not like the G12A: the controller reaches DRAM through a
pipeline stage with a gate of its own, sys_ampipe_eth. Nothing else
needs that gate, so clk_disable_unused switches it off and transfers
stop. The T7 therefore gets its own clock list, with the gate as a
fourth entry, and the driver requires it. The MMC controllers on this
SoC have the same arrangement, and that fix is already upstream.

Tested on next-20261002 on a VIM4, with "clk: meson: t7: keep the memory
fabric clocks running" (clk-meson-next) applied on top. That patch is
needed before any DMA on this SoC works. With unused clocks being
disabled normally, the port comes up at 1Gbit/s, 930Mbit/s sustained
receive, and no MAC error counters move.

This overlaps with Xianwei Zhao's "[PATCH v2 0/3] t7: add some nodes for
Amlogc t7.", which defines amlogic,t7-dwmac with the axg fallback,
snps,dwmac-4.00 and three clocks. On my board the MAC reports Synopsys
ID 0x51, which is DWMAC_CORE_5_10 in common.h, and the port does not
survive the unused clock sweep without the pipeline gate. I am sending
this so the code is on the list, not to race, and I will drop or rebase
whatever overlaps once we agree. Patch 1 is the oneOf rewrite Conor
asked for on that thread.

Lucas Tanure (6):
  dt-bindings: net: amlogic,meson-dwmac: spell out the compatible
    combinations
  dt-bindings: net: amlogic,meson-dwmac: add amlogic,t7-dwmac
  net: stmmac: dwmac-meson8b: add support for the Amlogic T7
  arm64: dts: amlogic: t7: add the ethernet pinctrl nodes
  arm64: dts: amlogic: t7: add the ethernet controller
  arm64: dts: amlogic: t7: khadas-vim4: enable the ethernet port

 .../bindings/net/amlogic,meson-dwmac.yaml     | 77 ++++++++++++----
 .../amlogic/amlogic-t7-a311d2-khadas-vim4.dts | 28 ++++++
 arch/arm64/boot/dts/amlogic/amlogic-t7.dtsi   | 87 +++++++++++++++++++
 .../ethernet/stmicro/stmmac/dwmac-meson8b.c   | 19 ++++
 4 files changed, 196 insertions(+), 15 deletions(-)


base-commit: f0406245cb9855e6318335a8a223551354291a46
-- 
2.56.0


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