[PATCH v4 0/7] Add ethernet support for the Amlogic T7

[Lucas Tanure <tanure@linux.com>]

The T7 has the same ethernet glue as the G12A. This adds the binding,
the driver support and the device tree nodes, and enables the port on
the Khadas VIM4.

Two clocks are new. The pipeline stage between the controller and the
DRAM has its own gate, which nothing else claims. The glue registers
sit in a block gated by sys_ethphy, so far claimed only by the MDIO
mux, which probes after the glue is programmed: every write to
PRG_ETH0/1 was lost. The T7 node lists that clock as "pclk".

The delays follow ethernet-controller.yaml: phy-mode is never changed,
the PHY adds the 2ns, and the T7 accepts only rx-internal-delay-ps, as
fine tuning. Its TX side is a quarter-period phase selector with no
small step, so tx-internal-delay-ps is not valid for it. The VIM4 is
plain rgmii-id. v3 said the RTL8211F TX delay did not work; that test
ran with the glue registers gated, so the bootloader's MAC TX delay
stayed on and the link had 4ns on TX.

Tested on v7.3-4494-g2a08195e4db5 plus "clk: meson: t7: keep the
memory fabric clocks running" (clk-meson-next): 940/941Mbit/s with
iperf3, no CRC error in 421k frames.

Overlaps with Xianwei Zhao's "[PATCH v2 0/3] t7: add some nodes for
Amlogc t7."; I will drop or rebase whatever overlaps once we agree.

Changes since v3:
 - phy-mode untouched, the PHY adds the 2ns, rx-internal-delay-ps is
   tuning only, tx-internal-delay-ps not valid for the T7
 - 0 dropped from rx-internal-delay-ps; vendor delay
   properties explicitly false for the T7
 - init_delays callback; the old parsing moved into the older-SoC
   function, marked not for new SoCs; patch 4 renamed
 - VIM4 without tx-internal-delay-ps, the PHY TX delay works
 - Meson8m2 moved to the dwmac-3.70a list; its boards warn in
   dtbs_check until Martin's dtsi patch lands
 - the delay table in ethernet-controller.yaml dropped
 - Martin's Reviewed-by on patch 3

Changes since v2:
 - the controller-side delays are applied on a T7-only path instead of
   changing every Amlogic board (Andrew); the PHY mode left over comes
   from phy_fix_phy_mode_for_mac_delays() (Maxime)
 - tx-internal-delay-ps is checked against the four values the hardware
   has, in the binding and in the driver, instead of being truncated
   (Sashiko)
 - amlogic,tx-delay-ns and amlogic,rx-delay-ns are not valid for the T7
   (Neil, Andrew)
 - the on-chip PHY no longer carries max-speed, phylib reads what the
   chip reports (Andrew); same for the RTL8211F on the VIM4
 - the PHY interrupt line, GPIOH_6, is described on the VIM4 (Sashiko)
 - new: the T7 node owns sys_ethphy as "pclk", see above
 - new patch 8: the delay ownership table in ethernet-controller.yaml
 - no longer RFC
 - Conor's Acked-by dropped from patch 2 and Neil's Reviewed-by from
   patch 6, as both patches changed. Patches 1, 3 and 5 only moved in
   the series, so their tags stay.

Changes since v1:
 - new patch 1: honour tx-internal-delay-ps and rx-internal-delay-ps in
   the rgmii-*id modes, and pass the PHY whatever delay is left over
 - vim4: phy-mode rgmii -> rgmii-id, and amlogic,tx-delay-ns plus
   rx-internal-delay-ps replaced by tx-internal-delay-ps = <2000>.
   Neil's Reviewed-by dropped from this one, the change is not cosmetic

Lucas Tanure (7):
  dt-bindings: net: amlogic,meson-dwmac: list the compatible
    combinations
  dt-bindings: net: amlogic,meson-dwmac: add amlogic,t7-dwmac
  net: stmmac: dwmac-meson8b: add support for the Amlogic T7
  net: stmmac: dwmac-meson8b: follow the generic RGMII delay rules on
    the 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     |  89 +++++++++--
 .../amlogic/amlogic-t7-a311d2-khadas-vim4.dts |  19 +++
 arch/arm64/boot/dts/amlogic/amlogic-t7.dtsi   |  88 +++++++++++
 .../ethernet/stmicro/stmmac/dwmac-meson8b.c   | 139 +++++++++++++-----
 4 files changed, 284 insertions(+), 51 deletions(-)

-- 
2.56.0