Re: [PATCH v4 1/2] dt-bindings: i3c: Add adi-i3c-master

Marcelo Schmitt
2025-07-02T22:07:00Z

Hello,

On 07/02, Jorge Marques wrote:
> On Fri, Jun 27, 2025 at 06:02:26PM +0200, Jorge Marques wrote:
> > On Fri, Jun 27, 2025 at 04:49:19PM +0200, Krzysztof Kozlowski wrote:
> > > On 27/06/2025 16:38, Jorge Marques wrote:
> > > > On Fri, Jun 27, 2025 at 08:56:55AM +0200, Krzysztof Kozlowski wrote:
> > > >> On Thu, Jun 26, 2025 at 12:07:36PM +0200, Jorge Marques wrote:
> > > >>> Add bindings doc for ADI I3C Controller IP core, a FPGA synthesizable IP
> > > >>> core that implements the MIPI I3C Basic controller specification.
> > > >>
...
>
> I went after the reason of the historically -1.00.a suffix and
> discovered that they came into existence due to AMD Xilinx auto
> generation devicetree tool SDTGen
> https://github.com/Xilinx/system-device-tree-xlnx
> that would automatically suffix with the IP version, defaulting to 1.00.a,
> and for a seamless experience, the were copied over to the dt-bindings.
>
> The adi,axi-pwmgen dt-binding went more creative and suffixed with
> -2.00.a, while never enforcing Vivado to yield the devicetree with such
> value (Major version is asserted in the driver through reg access, the
> current core version is v2.1.1)
>
> Testing on my side (AMD Xilinx Vivado 2024.2), it seems Vivado now
> defaults to 1.0, so the previous bindings from the other IPs are not
> accurate anymore, either, (axi-pwmgen auto gens
> `compatible = "xlnx,axi-pwm-gen-1.0";` (`xlnx` instead of `adi`, also)).
>
> For fun, the current Vivado version thinks the devicetree node for the
> i3c master should be as follows:
>
> i3c_host_interface: i3c_controller_host_interface@44a00000 {
> compatible = "xlnx,i3c-controller-host-interface-1.0";
> reg = <0x44a00000 0x10000>;
> clocks = <&clkc 15>;
> clock-names = "s_axi_aclk";
> };
>
> Let me know if we can drop the suffix, or replace with something else.
> The current register defined core version is v0.1.0.

I have no say in how dt-bindings should be, but having the IP version number
automatically generated doesn't sound like a sane thing to do IMHO. Maybe try to
standardize with -1.00.a suffix? Though one could also argue about dropping such
suffixes. Since we were told that the convention is to have the file name to
follow the compatible, I would go with 'xlnx,i3c-controller-host-interface'
(without any suffix) so the file name is smaller and clearer IMHO. dt maintainers
might prefer that in a different way.

Best regards,
Marcelo