Re: [PATCH v2 2/3] dt-bindings: mmc: Add bindings for LiteSDCard

["Gabriel L. Somlo" <gsomlo@gmail.com>]

Hi Geert,

On Mon, Dec 06, 2021 at 11:18:18AM +0100, Geert Uytterhoeven wrote:
> On Sat, Dec 4, 2021 at 9:41 PM Gabriel Somlo <gsomlo@gmail.com> wrote:
> > LiteSDCard is a small footprint, configurable SDCard core for FPGA
> > based system on chips.
> >
> > Signed-off-by: Gabriel Somlo <gsomlo@gmail.com>
> 
> And after reviewing the driver...
> 
> > --- /dev/null
> > +++ b/Documentation/devicetree/bindings/mmc/litex,mmc.yaml
> > @@ -0,0 +1,63 @@
> > +# SPDX-License-Identifier: GPL-2.0-or-later OR BSD-2-Clause
> > +%YAML 1.2
> > +---
> > +$id: http://devicetree.org/schemas/mmc/litex,mmc.yaml#
> > +$schema: http://devicetree.org/meta-schemas/core.yaml#
> > +
> > +title: LiteX LiteSDCard device
> > +
> > +maintainers:
> > +  - Gabriel Somlo <gsomlo@gmail.com>
> > +
> > +description: |
> > +  LiteSDCard is a small footprint, configurable SDCard core for FPGA based
> > +  system on chips.
> > +
> > +  The hardware source is Open Source and can be found on at
> > +  https://github.com/enjoy-digital/litesdcard/.
> > +
> > +allOf:
> > +  - $ref: mmc-controller.yaml#
> > +
> > +properties:
> > +  compatible:
> > +    const: litex,mmc
> > +
> > +  reg:
> > +    items:
> > +      - description: PHY registers
> > +      - description: CORE registers
> > +      - description: DMA Reader buffer
> > +      - description: DMA Writer buffer
> > +      - description: IRQ registers
> 
> The last one is optional...
> 
> > +
> > +  reg-names:
> > +    items:
> > +      - const: phy
> > +      - const: core
> > +      - const: reader
> > +      - const: writer
> > +      - const: irq
> 
> Likewise.
> 
> > +
> > +  interrupts:
> > +    maxItems: 1
> > +
> > +required:
> > +  - compatible
> > +  - reg
> 
> reg-names, as the driver needs it (and it's good practice anyway).
> 
> > +  - interrupts
> 
> Interrupts is optional.
> 
> I tried to link it to reg{,-names}:
> 
>     if:
>       not:
>         required:
>           - interrupts
>     then:
>       properties:
>         reg:
>           maxItems: 4
>         reg-names:
>           maxItems: 4
> 
> but that doesn't seem to work. Anyone with a clue?

For now I'm queueing this up for v3, unless we get more ideas:

@@ -29,7 +29,9 @@ properties:
       - description: CORE registers
       - description: DMA Reader buffer
       - description: DMA Writer buffer
-      - description: IRQ registers
+      - description: IRQ registers (optional)
+    minItems: 4
+    maxItems: 5
 
   reg-names:
     items:
@@ -37,7 +39,9 @@ properties:
       - const: core
       - const: reader
       - const: writer
-      - const: irq
+      - const: irq (optional)
+    minItems: 4
+    maxItems: 5
 
   interrupts:
     maxItems: 1
@@ -45,7 +49,7 @@ properties:
 required:
   - compatible
   - reg
-  - interrupts
+  - reg-names

Some of the *.txt formatted files in Documentation/devicetree/bindings/mmc
had an explicit "Optional" section, but all the .yaml formatted ones
just seem to assume that if it's not under `required:`, it's
implicitly optional. So I'm removing `interrupts` from `required`, and
adding `reg-names`, as you pointed out.

Thanks,
--Gabriel

 
> > +
> > +additionalProperties: false
> > +
> > +examples:
> > +  - |
> > +    mmc: mmc@12005000 {
> > +        compatible = "litex,mmc";
> > +        reg = <0x12005000 0x100>,
> > +              <0x12003800 0x100>,
> > +              <0x12003000 0x100>,
> > +              <0x12004800 0x100>,
> > +              <0x12004000 0x100>;
> > +        reg-names = "phy", "core", "reader", "writer", "irq";
> > +        interrupts = <4>;
> > +    };
> > --
> > 2.31.1
> >
> 
> 
> -- 
> Gr{oetje,eeting}s,
> 
>                         Geert
> 
> --
> Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@linux-m68k.org
> 
> In personal conversations with technical people, I call myself a hacker. But
> when I'm talking to journalists I just say "programmer" or something like that.
>                                 -- Linus Torvalds