On 21/06/2023 10:01, Conor Dooley wrote:
On Wed, Jun 21, 2023 at 08:37:02AM +0100, Lucas Tanure wrote:
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?
No, you can't.
I think Yes, as I can see a few compatible strings in dts that don't
exist anywhere else.
Aye, but we do not want to propagate that. New stuff should not be
adding undocumented compatibles, and those that are undocumented should
be documented.
Documentation is ongoing, it takes time !
Neil
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?
You are following the rules from the dts point of view, you just need a
3rd patch in which you document the pattern you have added here in
amlogic,meson-uart.yaml. It is probably something like:
+ - items:
+ - const: amlogic,meson-t7-uart
+ - const: amlogic,meson-s4-uart
But I have not tested that, I just wrote that in my mail client.
Cheers,
Conor.
