Re: [PATCH 1/3] dt-bindings: spi: Add VIA/WonderMedia serial flash controller

From: Krzysztof Kozlowski <krzk@kernel.org>
To: Alexey Charkov <alchark@gmail.com>, Rob Herring <robh@kernel.org>
Cc: Mark Brown <broonie@kernel.org>,
	Krzysztof Kozlowski <krzk+dt@kernel.org>,
	Conor Dooley <conor+dt@kernel.org>,
	Tudor Ambarus <tudor.ambarus@linaro.org>,
	Pratyush Yadav <pratyush@kernel.org>,
	Michael Walle <mwalle@kernel.org>,
	Miquel Raynal <miquel.raynal@bootlin.com>,
	Richard Weinberger <richard@nod.at>,
	Vignesh Raghavendra <vigneshr@ti.com>,
	linux-spi@vger.kernel.org, devicetree@vger.kernel.org,
	linux-kernel@vger.kernel.org, linux-mtd@lists.infradead.org,
	linux-arm-kernel@lists.infradead.org
Subject: Re: [PATCH 1/3] dt-bindings: spi: Add VIA/WonderMedia serial flash controller
Date: Fri, 6 Jun 2025 10:29:44 +0200	[thread overview]
Message-ID: <2b520ae5-eb0d-40eb-ba73-cc18759f33b9@kernel.org> (raw)
In-Reply-To: <CABjd4Yz3w75PtkRk_edzD5yf6b2xPuf20gopbm8ygddgCBfpkw@mail.gmail.com>

On 15/05/2025 21:50, Alexey Charkov wrote:
>>> +
>>> +  "#address-cells":
>>> +    const: 1
>>> +
>>> +  "#size-cells":
>>> +    const: 0
>>
>> This follows the SPI binding, right? Drop these 2 and add a $ref to
>> spi-controller.yaml.
> 
> Need some advice here. While this controller speaks SPI protocol to
> its connected flash chips, it's a special-purpose thing that doesn't
> expose much SPI functionality to the outside world, nor can it drive
> any SPI devices other than SPI NOR flash. Does that still qualify as
> an SPI controller as far as the bindings are concerned?
> 
> Happy to reference the spi-controller.yaml binding if so.

SPI NOR flashes are still child devices of an SPI controller. You can
look at other examples - aren't they all using spi-controller? Why this
would be different? Unless you found some cases that are different, but
then which ones?

Best regards,
Krzysztof