Re: [PATCH 2/5] dt-bindings: i2c: renesas,riic: Document R9A09G057 support

From: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
To: Prabhakar <prabhakar.csengg@gmail.com>,
	Geert Uytterhoeven <geert+renesas@glider.be>,
	Chris Brandt <chris.brandt@renesas.com>,
	Andi Shyti <andi.shyti@kernel.org>,
	Rob Herring <robh+dt@kernel.org>,
	Krzysztof Kozlowski <krzysztof.kozlowski+dt@linaro.org>,
	Conor Dooley <conor+dt@kernel.org>,
	Magnus Damm <magnus.damm@gmail.com>,
	Wolfram Sang <wsa+renesas@sang-engineering.com>
Cc: linux-renesas-soc@vger.kernel.org, linux-i2c@vger.kernel.org,
	devicetree@vger.kernel.org, linux-kernel@vger.kernel.org,
	Fabrizio Castro <fabrizio.castro.jz@renesas.com>,
	Lad Prabhakar <prabhakar.mahadev-lad.rj@bp.renesas.com>
Subject: Re: [PATCH 2/5] dt-bindings: i2c: renesas,riic: Document R9A09G057 support
Date: Sat, 9 Mar 2024 13:00:48 +0100	[thread overview]
Message-ID: <7082ed3b-d6d0-4228-b7a6-7c0e0e46b8e2@linaro.org> (raw)
In-Reply-To: <20240308172726.225357-3-prabhakar.mahadev-lad.rj@bp.renesas.com>

On 08/03/2024 18:27, Prabhakar wrote:
> From: Lad Prabhakar <prabhakar.mahadev-lad.rj@bp.renesas.com>
> 
> Document support for the I2C Bus Interface (RIIC) available in the
> Renesas RZ/V2H (R9A09G057) SoC.
> 
> The RIIC interface in the Renesas RZ/V2H differs from RZ/A in a
> couple of ways:
> - Register offsets for the RZ/V2H SoC differ from those of the RZ/A SoC.
> - RZ/V2H register access is 8-bit, whereas RZ/A supports 8/16/32-bit.
> - RZ/V2H has some bit differences in the slave address register.
> 
> To accommodate these differences in the existing driver, a new compatible
> string "renesas,riic-r9a09g057" is added.
> 
> Signed-off-by: Lad Prabhakar <prabhakar.mahadev-lad.rj@bp.renesas.com>
> Reviewed-by: Fabrizio Castro <fabrizio.castro.jz@renesas.com>

I have doubts this are true reviews. What did it even show? Why this
review did not point problem with generic compatible?

> ---
>  .../devicetree/bindings/i2c/renesas,riic.yaml | 21 ++++++++++++-------
>  1 file changed, 13 insertions(+), 8 deletions(-)
> 
> diff --git a/Documentation/devicetree/bindings/i2c/renesas,riic.yaml b/Documentation/devicetree/bindings/i2c/renesas,riic.yaml
> index 63ac5fe3208d..2a7125688647 100644
> --- a/Documentation/devicetree/bindings/i2c/renesas,riic.yaml
> +++ b/Documentation/devicetree/bindings/i2c/renesas,riic.yaml
> @@ -15,14 +15,19 @@ allOf:
>  
>  properties:
>    compatible:
> -    items:
> -      - enum:
> -          - renesas,riic-r7s72100   # RZ/A1H
> -          - renesas,riic-r7s9210    # RZ/A2M
> -          - renesas,riic-r9a07g043  # RZ/G2UL and RZ/Five
> -          - renesas,riic-r9a07g044  # RZ/G2{L,LC}
> -          - renesas,riic-r9a07g054  # RZ/V2L
> -      - const: renesas,riic-rz      # generic RIIC compatible
> +    oneOf:
> +      - items:
> +          - enum:
> +              - renesas,riic-r7s72100   # RZ/A1H
> +              - renesas,riic-r7s9210    # RZ/A2M
> +              - renesas,riic-r9a07g043  # RZ/G2UL and RZ/Five
> +              - renesas,riic-r9a07g044  # RZ/G2{L,LC}
> +              - renesas,riic-r9a07g054  # RZ/V2L
> +          - const: renesas,riic-rz      # generic RIIC compatible
> +
> +      - items:
> +          - enum:
> +              - renesas,riic-r9a09g057  # RZ/V2H(P)

No, that does not look right. If you added generic compatible for all
RIIC then how can you add a new RIIC compatible which does not follow
generic one?

This shows the ridiculousness of these generic compatibles. They are
generic till you figure out the truth: oh crap, it's not generic.

Stop adding generic compatibles when they are not generic.

Best regards,
Krzysztof