[PATCH v1 1/4] dt-bindings: imx6q-pcie: Add reg-name "dbi2" and "atu" for i.MX8M PCIe Endpoint

[Frank Li]

On Tue, Jul 23, 2024 at 03:35:11PM +0100, Conor Dooley wrote:
> On Mon, Jul 22, 2024 at 04:47:29PM -0400, Frank Li wrote:
> > On Mon, Jul 22, 2024 at 05:37:14PM +0100, Conor Dooley wrote:
> > > On Mon, Jul 22, 2024 at 03:56:16PM +0800, Richard Zhu wrote:
> > > > Add reg-name: "dbi2", "atu" for i.MX8M PCIe Endpoint.
> > > > 
> > > > Signed-off-by: Richard Zhu <hongxing.zhu at nxp.com>
> > > > ---
> > > >  .../devicetree/bindings/pci/fsl,imx6q-pcie-ep.yaml  | 13 +++++++++----
> > > >  1 file changed, 9 insertions(+), 4 deletions(-)
> > > > 
> > > > diff --git a/Documentation/devicetree/bindings/pci/fsl,imx6q-pcie-ep.yaml b/Documentation/devicetree/bindings/pci/fsl,imx6q-pcie-ep.yaml
> > > > index a06f75df8458..309e8953dc91 100644
> > > > --- a/Documentation/devicetree/bindings/pci/fsl,imx6q-pcie-ep.yaml
> > > > +++ b/Documentation/devicetree/bindings/pci/fsl,imx6q-pcie-ep.yaml
> > > > @@ -65,11 +65,13 @@ allOf:
> > > >      then:
> > > >        properties:
> > > >          reg:
> > > > -          minItems: 2
> > > > -          maxItems: 2
> > > > +          minItems: 4
> > > > +          maxItems: 4
> > > >          reg-names:
> > > >            items:
> > > >              - const: dbi
> > > > +            - const: dbi2
> > > > +            - const: atu
> > > 
> > > New properties in the middle of the list is potentially an ABI break.
> > > Why not add them at the end?
> > 
> > Because it ref to snps,dw-pcie-ep.yaml, which already defined the reg
> > name orders.
> 
> Are you sure that it defines an order for reg? If it did, it would not
> allow what you already have in this binding. The order is actually
> defined in this file.

Sorry, I missed oneOf in snps,dw-pcie-ep.yaml. You are right.

Frank

> 
> > we using reg-names to get reg resource, I don't think it break
> > the ABI. Driver already auto detect both 'dbi2' or no 'dbi2' case.
> 
> Linux's might, another might not. I don't see any point in breaking the
> ABI when you can just put the entries at the end of he list and have no
> problems at all.
> 
> Thanks,
> Conor.
> 
> > > >              - const: addr_space
> > > >  
> > > >    - if:
> > > > @@ -129,8 +131,11 @@ examples:
> > > >  
> > > >      pcie_ep: pcie-ep at 33800000 {
> > > >        compatible = "fsl,imx8mp-pcie-ep";
> > > > -      reg = <0x33800000 0x000400000>, <0x18000000 0x08000000>;
> > > > -      reg-names = "dbi", "addr_space";
> > > > +      reg = <0x33800000 0x100000>,
> > > > +            <0x33900000 0x100000>,
> > > > +            <0x33b00000 0x100000>,
> > > > +            <0x18000000 0x8000000>;
> > > > +      reg-names = "dbi", "dbi2", "atu", "addr_space";
> > > >        clocks = <&clk IMX8MP_CLK_HSIO_ROOT>,
> > > >                 <&clk IMX8MP_CLK_HSIO_AXI>,
> > > >                 <&clk IMX8MP_CLK_PCIE_ROOT>;
> > > > -- 
> > > > 2.37.1
> > > > 
> > 
> >