On Tue, 5 Dec 2023 at 15:39, Krzysztof Kozlowski krzysztof.kozlowski@linaro.org wrote:
On 05/12/2023 10:45, Sumit Garg wrote:
- U-boot custodians list
On Tue, 5 Dec 2023 at 12:58, Krzysztof Kozlowski krzysztof.kozlowski@linaro.org wrote:
On 05/12/2023 08:13, Sumit Garg wrote:
@DT bindings maintainers,
Given the ease of maintenance of DT bindings within Linux kernel source tree, I don't have a specific objection there. But can we ease DTS testing for firmware/bootloader projects by providing a versioned release package for DT bindings? Or if someone else has a better idea here please feel free to chime in.
This doesn't work for you?:
https://git.kernel.org/pub/scm/linux/kernel/git/devicetree/devicetree-rebasi...
Thanks, this is certainly a good step which I wasn't aware of. Further simplification can be done to decouple devicetree source files from DT bindings.
Why?
I suppose you are already aware that Linux DTS files are a subset of what could be supported by devicetree schemas. There can be firmware/bootloader specific properties (one example being [1]) which Linux kernel can simply ignore. Will you be willing to add all of those DT properties to Linux DTS files and maintain them?
We already added them and we already maintain them. DTS describes the hardware, not the OS-subset of the hardware.
Let look at some numbers if your statement is justified or not for the example I gave:
u-boot$ git grep -nr bootph-* arch/arm* | wc -l 4079
linux$ git grep -nr bootph-* arch/arm* | wc -l 267
It looks like there is always going to be a catch up game regarding DT properties which either Linux kernel or u-boot or any other firmware/bootloader project don't care about.
However, DT bindings are something which should be common, the hardware description of a device should be universal. IMO, splitting
Both DT bindings and DTS should be common. I don't see the difference.
If we really care about DTS to be common then the contribution model has to change where there is a single repo hosting DT bindings and DTS. All other projects whether it is Linux kernel or u-boot or any other OS/firmware/bootloader are just consuming DTS files from that single repo. I suppose this is something that Linux DT maintainers have objected to in the past for ease of maintenance. I am not sure if you folks are willing to change that stance.
DT bindings alone would ease the compliance process for u-boot drivers in quite similar manner to Linux drivers.
[1] https://github.com/devicetree-org/dt-schema/blob/main/dtschema/schemas/bootp...
AFAIK, DT bindings should be forwards and backwards compatible.
The same with DTS.
So if you pick up DTS or DTB from any project tree (upstream kernel or stable kernel or u-boot) then DT schema validation would ensure that corresponding DTS or DTB doesn't regress the DT bindings.
And why is this argument to decouple DTS from bindings?
See above.
It's not really explained there. You can pick up DTS from any project and validate it against the repo Rob mentioned or against kernel. Whether DTS is in that repo or not, does not matter for your validation.
It is similar to your earlier argument to use the whole mainline kernel repo. What is the real benefit to keep DT bindings and DTS together when every project has to maintain a copy of DTS in its own source tree? It will be just a source of confusion for developers: - One DTS coming from devicetree-rebasing repo - One DTS coming from local project
-Sumit