Hi Niklas,
Am Freitag, 27. Oktober 2023, 18:14:32 CEST schrieb Niklas Cassel:
> On Fri, Oct 27, 2023 at 10:58:28AM -0500, Rob Herring wrote:
> > On Fri, Oct 27, 2023 at 9:56 AM Niklas Cassel <nks@xxxxxxxxxxx> wrote:
> > >
> > > From: Niklas Cassel <niklas.cassel@xxxxxxx>
> > >
> > > Even though rockchip-dw-pcie.yaml inherits snps,dw-pcie.yaml
> > > using:
> > >
> > > allOf:
> > > - $ref: /schemas/pci/snps,dw-pcie.yaml#
> > >
> > > and snps,dw-pcie.yaml does have the atu reg defined, in order to be
> > > able to use this reg, while still making sure 'make CHECK_DTBS=y'
> > > pass, we need to add this reg to rockchip-dw-pcie.yaml.
> > >
> > > All compatible strings (rockchip,rk3568-pcie and rockchip,rk3588-pcie)
> > > should have this reg.
> > >
> > > The regs in the example are updated to actually match pcie3x2 on rk3568.
> >
> > Breaking compatibility on these platforms is okay because ...?
>
> I don't follow, could you please elaborate?
you're adding the atu reg unconditionally as required element.
Newer kernel versions (strongly) _should_ work with older devicetrees.
So a kernel with that change should also work with a dtb build from the
old style.
DTBs are essentially part of the device firmware, so while some devices
can update theirs easily, you can't really require a dtb update.
I guess you could something like:
reg-names:
oneOf:
- deprecated: true
items:
- const: dbi
- const: apb
- const: config
- items:
- const: dbi
- const: apb
- const: config
- const: atu
(may not be accurate and to spec yet)
