On Wed, Jun 21, 2023 at 7:02 AM Krzysztof Kozlowski <krzysztof.kozlowski@xxxxxxxxxx> wrote: > > On 21/06/2023 00:09, Yixun Lan wrote: > >> + apb4: bus@fe000000 { > >> + compatible = "simple-bus"; > >> + reg = <0x0 0xfe000000 0x0 0x480000>; > >> + #address-cells = <2>; > >> + #size-cells = <2>; > >> + ranges = <0x0 0x0 0x0 0xfe000000 0x0 0x480000>; > >> + > >> + uart_A: serial@78000 { > >> + compatible = "amlogic,meson-t7-uart", > > ~~~~~~~~~~~~~~~~~ > > if you introduce new compatible string, then at least you need to document it > > so Documentation/devicetree/bindings/serial/amlogic,meson-uart.yaml need to be updated > > > > but my qeustion here, why bother introducing new compatible string if nothing > > changed with the compatible data? given the uart is same IP with g12a, can't we just > > use "amlogic,meson-g12-uart" for this? no only it will reduce the structure length of > > meson_uart_dt_match[], but also relieve maintainer's review burden? > > https://elixir.bootlin.com/linux/v6.1-rc1/source/Documentation/devicetree/bindings/writing-bindings.rst#L42 > > Best regards, > Krzysztof > Hi, I did not understand the recommendation here. Can I add "amlogic,meson-t7-uart" without Documentation changes? I think Yes, as I can see a few compatible strings in dts that don't exist anywhere else. My idea here is to add "amlogic,meson-t7-uart" for future use if ever created, like if we find a bug in the future that is only relevant to T7 soc. But for now, fallback to s4 uart, as it seems to be the same controller. >From Krzysztof said in the writing-bindings.rst, I am following the rules. So, what's the path forward here? Thanks Lucas