[PATCH 0/3] serial: 8250_dw: describe the Allwinner H616 UART configuration

[James Hilliard <james.hilliard1@gmail.com>]

H616 has 256-byte UART FIFOs, but lacks the DesignWare component parameter
register used to discover their capacity. Its debug-divisor and RS485
registers also overlap offsets used to probe optional DesignWare features.

Add an H616 compatible and select a fixed port configuration with the
documented FIFO capacity and receive trigger levels. Preserve the
BUSY-safe integer divisor path and keep the UART gate enabled during
termios changes. Attach the existing 8250 DMA path using single-byte
peripheral bursts, with channel acquisition and PIO fallback handled
by the normal startup path.

The patches add the binding, driver configuration and SoC DTS compatible
in that order. Based on tty-next at 1184f87e2790.

Assisted-by: Codex:gpt-6-astra
Signed-off-by: James Hilliard <james.hilliard1@gmail.com>
---
James Hilliard (3):
      dt-bindings: serial: snps-dw-apb-uart: add Allwinner H616
      serial: 8250_dw: configure the Allwinner H616 UART
      arm64: dts: allwinner: h616: identify the UART integration

 .../bindings/serial/snps-dw-apb-uart.yaml          |  1 +
 arch/arm64/boot/dts/allwinner/sun50i-h616.dtsi     | 12 +++---
 drivers/tty/serial/8250/8250.h                     |  1 +
 drivers/tty/serial/8250/8250_dw.c                  | 45 ++++++++++++++++++----
 drivers/tty/serial/8250/8250_port.c                |  8 ++++
 5 files changed, 54 insertions(+), 13 deletions(-)
---
base-commit: 1184f87e2790e8af9be3116f608d2e86b4792d7d
change-id: 20261022-submit-h616-uart-fifo-v1-c5afcdfe5cb0

Best regards,
--  
James Hilliard <james.hilliard1@gmail.com>