Re: [PATCH 1/2] dt-bindings: at24: add ST M24256E Additional Write lockable page support

[Rob Herring <robh@kernel.org>]

On Thu, Oct 17, 2024 at 08:41:25PM +0200, Marek Vasut wrote:
> The ST M24256E behaves as a regular M24C256, except for the E variant
> which uses up another I2C address for Additional Write lockable page.
> This page is 64 Bytes long and can contain additional data. Add entry
> for it, so users can describe that page in DT. Note that users still
> have to describe the main M24C256 area separately as that is on separate
> I2C address from this page.

I think this should be modelled as 1 node having 2 addresses, not 2 
nodes.

> 
> Unlike M24C32-D and M24C64-D, this part is specifically ST and does not
> have any comparable M24* counterparts from other vendors, hence the st,
> vendor prefix. Furthermore, the part name is M24256E without C between
> the 24 and 256, this is not a typo. Finally, there is M24C256-D part,
> which does contain 32 Bytes long Additional Write lockable page, which
> is a different part and not supported by this patch.
> 
> Datasheet: https://www.st.com/resource/en/datasheet/m24256e-f.pdf
> 
> Signed-off-by: Marek Vasut <marex@denx.de>
> ---
> Cc: Alexander Stein <alexander.stein@ew.tq-group.com>
> Cc: Arnd Bergmann <arnd@arndb.de>
> Cc: Bartosz Golaszewski <bartosz.golaszewski@linaro.org>
> Cc: Bartosz Golaszewski <brgl@bgdev.pl>
> Cc: Christoph Niedermaier <cniedermaier@dh-electronics.com>
> Cc: Conor Dooley <conor+dt@kernel.org>
> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
> Cc: Krzysztof Kozlowski <krzk+dt@kernel.org>
> Cc: Rob Herring <robh@kernel.org>
> Cc: devicetree@vger.kernel.org
> Cc: kernel@dh-electronics.com
> Cc: linux-i2c@vger.kernel.org
> ---
>  Documentation/devicetree/bindings/eeprom/at24.yaml | 2 ++
>  1 file changed, 2 insertions(+)
> 
> diff --git a/Documentation/devicetree/bindings/eeprom/at24.yaml b/Documentation/devicetree/bindings/eeprom/at24.yaml
> index b6239ec3512b3..590ba0ef5fa26 100644
> --- a/Documentation/devicetree/bindings/eeprom/at24.yaml
> +++ b/Documentation/devicetree/bindings/eeprom/at24.yaml
> @@ -141,6 +141,8 @@ properties:
>            - const: microchip,24aa025e48
>        - items:
>            - const: microchip,24aa025e64
> +      - items:
> +          - const: st,24256e-wl
>        - pattern: '^atmel,24c(32|64)d-wl$' # Actual vendor is st
>  
>    label:
> -- 
> 2.45.2
>