[PATCH v2] dt-bindings: i2c: renesas,rcar-i2c: allow 6 DMA channels

[PATCH v2] dt-bindings: i2c: renesas,rcar-i2c: allow 6 DMA channels

[Wolfram Sang]

R-Car Gen5 can make use of it.

Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
---

Change since v1: add check for limit on Gen3/4.

 .../bindings/i2c/renesas,rcar-i2c.yaml         | 18 ++++++++++++++++--
 1 file changed, 16 insertions(+), 2 deletions(-)

diff --git a/Documentation/devicetree/bindings/i2c/renesas,rcar-i2c.yaml b/Documentation/devicetree/bindings/i2c/renesas,rcar-i2c.yaml
index f9ede03c3287..bfd486be0109 100644
--- a/Documentation/devicetree/bindings/i2c/renesas,rcar-i2c.yaml
+++ b/Documentation/devicetree/bindings/i2c/renesas,rcar-i2c.yaml
@@ -83,14 +83,14 @@ properties:
 
   dmas:
     minItems: 2
-    maxItems: 4
+    maxItems: 6
     description:
       Must contain a list of pairs of references to DMA specifiers, one for
       transmission, and one for reception.
 
   dma-names:
     minItems: 2
-    maxItems: 4
+    maxItems: 6
     items:
       enum:
         - tx
@@ -137,6 +137,20 @@ allOf:
         dmas: false
         dma-names: false
 
+  - if:
+      properties:
+        compatible:
+          contains:
+            enum:
+              - renesas,rcar-gen3-i2c
+              - renesas,rcar-gen4-i2c
+    then:
+      properties:
+        dmas:
+          maxItems: 4
+        dma-names:
+          maxItems: 4
+
   - if:
       properties:
         compatible:
-- 
2.47.3

Re: [PATCH v2] dt-bindings: i2c: renesas,rcar-i2c: allow 6 DMA channels

[Conor Dooley]

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Acked-by: Conor Dooley <conor.dooley@microchip.com>
pw-bot: not-applicable

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Re: [PATCH v2] dt-bindings: i2c: renesas,rcar-i2c: allow 6 DMA channels

[Geert Uytterhoeven]

Hi Wolfram,

On Wed, 26 Aug 2026 at 10:35, Wolfram Sang
<wsa+renesas@sang-engineering.com> wrote:
> R-Car Gen5 can make use of it.
>
> Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>

Thanks for your patch!

> --- a/Documentation/devicetree/bindings/i2c/renesas,rcar-i2c.yaml
> +++ b/Documentation/devicetree/bindings/i2c/renesas,rcar-i2c.yaml
> @@ -83,14 +83,14 @@ properties:
>
>    dmas:
>      minItems: 2
> -    maxItems: 4
> +    maxItems: 6

Shouldn't this be 8, as there are 4 SYS-DMAC instances, and I couldn't
find a limitation w.r.t. I2C and specific SYS-DMAC instances?

>      description:
>        Must contain a list of pairs of references to DMA specifiers, one for
>        transmission, and one for reception.
>
>    dma-names:
>      minItems: 2
> -    maxItems: 4
> +    maxItems: 6
>      items:
>        enum:
>          - tx
> @@ -137,6 +137,20 @@ allOf:
>          dmas: false
>          dma-names: false
>
> +  - if:
> +      properties:
> +        compatible:
> +          contains:
> +            enum:
> +              - renesas,rcar-gen3-i2c
> +              - renesas,rcar-gen4-i2c
> +    then:
> +      properties:
> +        dmas:
> +          maxItems: 4
> +        dma-names:
> +          maxItems: 4
> +

I wouldn't bother adding further restrictions, as these are not related
to the actual I2C block, but to on-SoC wiring.  DMARQ is just a single
signal going from the I2C block to one or more DMAC instances.
The number also differs among I2C instances on an SoC.

BTW, all I2C instances on R-Car V3U have one DMA pair ;-)

>    - if:
>        properties:
>          compatible:

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