Re: [PATCH v6 3/3] dt-bindings: pci: layerscape-pci-ep: Add snps,dw-pcie-ep.yaml reference

[Frank Li <Frank.li@nxp.com>]

On Tue, Mar 05, 2024 at 08:37:19AM -0600, Rob Herring wrote:
> On Mon, Mar 04, 2024 at 02:08:41PM -0500, Frank Li wrote:
> > On Mon, Mar 04, 2024 at 12:20:49PM -0600, Rob Herring wrote:
> > > On Fri, Mar 01, 2024 at 11:27:41AM -0500, Frank Li wrote:
> > > > Add snps,dw-pcie-ep.yaml.
> > > > 
> > > > Remove context that exist in snps,dw-pcie-ep.yaml.
> > > > 
> > > > Add an example for pcie-ep.
> > > > 
> > > > Signed-off-by: Frank Li <Frank.Li@nxp.com>
> > > > ---
> > > >  .../bindings/pci/fsl,layerscape-pcie-ep.yaml  | 54 ++++++++++---------
> > > >  1 file changed, 29 insertions(+), 25 deletions(-)
> > > > 
> > > > diff --git a/Documentation/devicetree/bindings/pci/fsl,layerscape-pcie-ep.yaml b/Documentation/devicetree/bindings/pci/fsl,layerscape-pcie-ep.yaml
> > > > index cf517e4e46a33..07965683beece 100644
> > > > --- a/Documentation/devicetree/bindings/pci/fsl,layerscape-pcie-ep.yaml
> > > > +++ b/Documentation/devicetree/bindings/pci/fsl,layerscape-pcie-ep.yaml
> > > > @@ -10,8 +10,7 @@ maintainers:
> > > >    - Frank Li <Frank.Li@nxp.com>
> > > >  
> > > >  description:
> > > > -  This PCIe RC controller is based on the Synopsys DesignWare PCIe IP
> > > > -  and thus inherits all the common properties defined in snps,dw-pcie.yaml.
> > > > +  This PCIe RC controller is based on the Synopsys DesignWare PCIe IP.
> > > >  
> > > >    This controller derives its clocks from the Reset Configuration Word (RCW)
> > > >    which is used to describe the PLL settings at the time of chip-reset.
> > > > @@ -35,31 +34,18 @@ properties:
> > > >        - const: fsl,ls-pcie-ep
> > > >  
> > > >    reg:
> > > > -    description: base addresses and lengths of the PCIe controller register blocks.
> > > > +    maxItems: 2
> > > > +
> > > > +  reg-names:
> > > > +    maxItems: 2
> > > >  
> > > >    interrupts:
> > > > -    description: A list of interrupt outputs of the controller. Must contain an
> > > > -      entry for each entry in the interrupt-names property.
> > > > +    minItems: 1
> > > > +    maxItems: 3
> > > >  
> > > >    interrupt-names:
> > > >      minItems: 1
> > > >      maxItems: 3
> > > > -    description: It could include the following entries.
> > > > -    items:
> > > > -      oneOf:
> > > > -        - description:
> > > > -            Used for interrupt line which reports AER events when
> > > > -            non MSI/MSI-X/INTx mode is used.
> > > > -          const: aer
> > > > -        - description:
> > > > -            Used for interrupt line which reports PME events when
> > > > -            non MSI/MSI-X/INTx mode is used.
> > > > -          const: pme
> > > > -        - description:
> > > > -            Used for SoCs(like ls2080a, lx2160a, ls2080a, ls2088a, ls1088a)
> > > > -            which has a single interrupt line for miscellaneous controller
> > > > -            events(could include AER and PME events).
> > > > -          const: intr
> > > >  
> > > >    fsl,pcie-scfg:
> > > >      $ref: /schemas/types.yaml#/definitions/phandle
> > > > @@ -68,10 +54,7 @@ properties:
> > > >        The second entry is the physical PCIe controller index starting from '0'.
> > > >        This is used to get SCFG PEXN registers
> > > >  
> > > > -  dma-coherent:
> > > > -    description: Indicates that the hardware IP block can ensure the coherency
> > > > -      of the data transferred from/to the IP block. This can avoid the software
> > > > -      cache flush/invalid actions, and improve the performance significantly
> > > > +  dma-coherent: true
> > > >  
> > > >    big-endian:
> > > >      $ref: /schemas/types.yaml#/definitions/flag
> > > > @@ -85,3 +68,24 @@ required:
> > > >    - reg
> > > >    - interrupt-names
> > > >  
> > > > +allOf:
> > > > +  - $ref: /schemas/pci/snps,dw-pcie-ep.yaml#
> > > > +
> > > > +examples:
> > > > +  - |
> > > > +    #include <dt-bindings/interrupt-controller/arm-gic.h>
> > > > +
> > > > +    soc {
> > > > +      #address-cells = <2>;
> > > > +      #size-cells = <2>;
> > > > +
> > > > +      pcie-ep@3400000 {
> > > > +        compatible = "fsl,ls1028a-pcie-ep", "fsl,ls-pcie-ep";
> > > > +        reg = <0x00 0x03400000 0x0 0x00100000
> > > > +              0x80 0x00000000 0x8 0x00000000>;
> > > > +        reg-names = "dbi", "addr_space";
> > > > +        interrupts = <GIC_SPI 108 IRQ_TYPE_LEVEL_HIGH>; /* PME interrupt */
> > > 
> > > PME or...
> > > 
> > > > +        interrupt-names = "app";
> > > 
> > > app? You seem to just be changing the names to make the example happy. 
> > > What do the dts files have? You need to make those pass.
> > 
> > It's on my plan.
> > 
> > First need change 'regs' to 'dbi'. 
> > 
> > https://lore.kernel.org/linux-pci/20240229194559.709182-1-Frank.Li@nxp.com/
> > 
> > After that, I can update all dts.
> 
> No! 
> 
> I'm saying you shouldn't be changing the dts files. That's an ABI 
> which you are likely breaking. You should adjust the binding so the dts 
> files pass. The exception is if you know the change is safe and not 
> going to break the ABI or the dts is just been wrong all along (e.g. 
> missing a compatible the OS doesn't rely on).

The problem is that I have not method to make dts check without warning.

If using snps,dw-pcie-ep.yaml/snps,dw-pcie.yaml, it always complain 'regs'
and 'pme'.

If update snps,dw-pcie-ep-.yaml/snps,dw-pcie.yaml, there are two name
'regs' and 'dbi' will be the same thing. it should be bad.

If don't included snps,dw-pcie-ep-.yaml/snps,dw-pcie.yaml, I have to
duplicate most parts, which already in these files.

If you have good method, let me know.

Frank

> 
> Rob