Currently, since Aspeed also has a similar driver, there is some code
with identical structures on both sides, but a common framework is
lacking. Therefore, this series introduces a generic UART routing
framework. It also moves aspeed-uart-routing.c under this generic
framework and makes it use the interfaces provided by the generic
framework. At the same time, StarFive also registers its own driver
based on this generic framework.

StarFive JHB100 UART Routing allows dynamic routing of inputs between
built-in UARTs and physical serial I/O ports, enabling use cases such
as Host <-> BMC communication via UARTs.

This series has been tested on the EVB1 board.

changes since v2:

PATCH 2:
- Add a "depends on ARCH_ASPEED || COMPILE_TEST" to the "UART routing drivers"
  menu.

PATCH 3:
- Move the binding to bindings/soc/starfive/ and update the $id

PATCH 4:
- Append the depends on ARCH_STARFIVE to the "UART routing drivers"
- Use RST literal blocks instead of backslash-escaped asterisks in the
  sysfs ABI documentation.
- Update the MAINTAINERS entry for binding.

v2: https://lore.kernel.org/all/20260905102901.126035-1-changhuang.liang@starfivetech.com/
v1: https://lore.kernel.org/all/20260830065118.51551-1-changhuang.liang@starfivetech.com/

Changhuang Liang (4):
  uart-routing: Add common UART routing framework
  soc: aspeed: Move UART routing driver to drivers/uart-routing
  dt-bindings: soc: starfive: Add StarFive JHB100 UART routing
  uart-routing: Add UART Routing driver for StarFive JHB100 SoC

 .../sysfs-driver-starfive-uart-routing        |  49 ++
 .../soc/starfive/starfive,uart-routing.yaml   |  46 ++
 Documentation/driver-api/index.rst            |   1 +
 Documentation/driver-api/uart-routing.rst     | 145 +++++
 MAINTAINERS                                   |  25 +
 drivers/Kconfig                               |   2 +
 drivers/Makefile                              |   1 +
 drivers/soc/aspeed/Kconfig                    |  10 -
 drivers/soc/aspeed/Makefile                   |   1 -
 drivers/soc/aspeed/aspeed-uart-routing.c      | 601 ------------------
 drivers/uart-routing/Kconfig                  |  45 ++
 drivers/uart-routing/Makefile                 |   5 +
 drivers/uart-routing/aspeed-uart-routing.c    | 415 ++++++++++++
 drivers/uart-routing/starfive-uart-routing.c  | 192 ++++++
 drivers/uart-routing/uart-routing.c           | 200 ++++++
 drivers/uart-routing/uart-routing.h           |  84 +++
 16 files changed, 1210 insertions(+), 612 deletions(-)
 create mode 100644 Documentation/ABI/testing/sysfs-driver-starfive-uart-routing
 create mode 100644 Documentation/devicetree/bindings/soc/starfive/starfive,uart-routing.yaml
 create mode 100644 Documentation/driver-api/uart-routing.rst
 delete mode 100644 drivers/soc/aspeed/aspeed-uart-routing.c
 create mode 100644 drivers/uart-routing/Kconfig
 create mode 100644 drivers/uart-routing/Makefile
 create mode 100644 drivers/uart-routing/aspeed-uart-routing.c
 create mode 100644 drivers/uart-routing/starfive-uart-routing.c
 create mode 100644 drivers/uart-routing/uart-routing.c
 create mode 100644 drivers/uart-routing/uart-routing.h

--
2.25.1