Messages in this thread | | | Date | Fri, 26 Aug 2022 12:54:47 +0300 | From | Serge Semin <> | Subject | Re: [PATCH 02/13] dt-bindings: memory: snps: Add Baikal-T1 DDRC support |
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On Tue, Aug 23, 2022 at 11:12:28AM +0300, Krzysztof Kozlowski wrote: > On 22/08/2022 22:19, Serge Semin wrote: > > Baikal-T1 DDR controller is based on the DW uMCTL2 DDRC IP-core v2.51a > > with up to DDR3 protocol capability and 32-bit data bus + 8-bit ECC. There > > are individual IRQs for each ECC and DFI events.The dedicated scrubber >
> Missing space before "The".
Ok. Thanks.
> > > clock source is absent since it's fully synchronous to the core clock. >
> You need allOf:if-then restricting this per variant.
I really don't like the allOf-if-if-etc pattern because it gets to be very bulky if all the vendor-specific and generic platform peculiarities are placed in there. I am more keen of having a generic DT-schema which would be then allOf-ed by the vendor-specific device bindings. What do you think I'd provide such design in this case too?
But I'll need to move the compatible property definition to the "select" property. Like this:
Documentation/devicetree/bindings/memory-controllers/snps,dw-umctl2-ddrc.yaml: +[...] +# Please create a separate DT-schema for your DW uMCTL2 DDR controller +# and make sure it's assigned with the vendor-specific compatible string. +select: + properties: + compatible: + oneOf: + - deprecated: true + description: Synopsys DW uMCTL2 DDR controller v3.80a + const: snps,ddrc-3.80a + - description: Synopsys DW uMCTL2 DDR controller + const: snps,dw-umctl2-ddrc + - description: Xilinx ZynqMP DDR controller v2.40a + const: xlnx,zynqmp-ddrc-2.40a + required: + - compatible + +properties: + compatible: true +[...] +required: + - compatible + - reg + - interrupts + +additionalProperties: true
After that the "snps,dw-umctl2-ddrc.yaml" schema can be referenced in the allOf composition. Like this:
Documentation/devicetree/bindings/memory-controllers/baikal,bt1-ddrc.yaml: +[...] +allOf: + - $ref: /schemas/memory-controllers/snps,dw-umctl2-ddrc.yaml# +[...]
At the same time the generic DT-schema will be used to evaluate the "snps,ddrc-3.80a", "snps,dw-umctl2-ddrc" and "xlnx,zynqmp-ddrc-2.40a" device nodes as before. What do you think about that?
One big positive side of this that even though the generic schema can't define the IRQ/resets/clocks phandlers order because various platforms may have different external signals setup, the vendor-specific schema can and should. So I'll be able to describe the Baikal-T1 DDRC specific properties (clocks, clock-names, interrupts, interrupt-names, etc) in much more details including the reference signals order what you asked in the previous patch review.
-Sergey
> > > In addition to that the DFI-DDR PHY CSRs can be accessed via a separate > > registers space. > > > > Signed-off-by: Serge Semin <Sergey.Semin@baikalelectronics.ru> > > --- > > .../memory-controllers/snps,dw-umctl2-ddrc.yaml | 10 +++++++++- > > 1 file changed, 9 insertions(+), 1 deletion(-) > > > > diff --git a/Documentation/devicetree/bindings/memory-controllers/snps,dw-umctl2-ddrc.yaml b/Documentation/devicetree/bindings/memory-controllers/snps,dw-umctl2-ddrc.yaml > > index 8db92210cfe1..899a6c5f9806 100644 > > --- a/Documentation/devicetree/bindings/memory-controllers/snps,dw-umctl2-ddrc.yaml > > +++ b/Documentation/devicetree/bindings/memory-controllers/snps,dw-umctl2-ddrc.yaml > > @@ -26,6 +26,7 @@ properties: > > enum: > > - snps,ddrc-3.80a > > - xlnx,zynqmp-ddrc-2.40a > > + - baikal,bt1-ddrc >
> Messed order. Don't add stuff at the end, but in alphabetical order.
Ok. But could you please give me a reference with this requirement documented? I've submitted many DT-bindings patches with the compatible property updates and none of them received such comment from Rob.
> > > > > interrupts: > > description: > > @@ -49,7 +50,14 @@ properties: > > enum: [ ecc_ce, ecc_ue, ecc_ap, ecc_sbr, dfi_e ] > > > > reg: > > - maxItems: 1 > > + minItems: 1 > > + maxItems: 2 > > + > > + reg-names: > > + minItems: 1 > > + items: > > + - const: umctl2 > > + - const: phy >
> You need allOf:if-then restricting this per variant.
Please see my comment above regarding possible solution of this.
-Sergey
> > Best regards, > Krzysztof
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