Re: [PATCH v1 2/8] MT9M114: Add pad-slew-rate DT-binding

Sakari Ailus
2025-02-27T10:14:08Z

Hi Mathis,

On Wed, Feb 26, 2025 at 04:39:23PM +0100, Mathis Foerst wrote:
> The MT9M114 supports the different slew rates (0 to 7) on the output pads.

"the output pads" probably means pixel data interface (DVP or CSI-2)
signals in this cases? I suppose this is about clock modulation?
It'd be good to say that.

> At the moment, this is hardcoded to 7 (the fastest rate).
> The user might want to change this values due to EMC requirements.
>
> Add the 'pad-slew-rate' property to the MT9M114 DT-bindings for selecting
> the desired slew rate.
>
> Signed-off-by: Mathis Foerst <mathis.foerst@mt.com>
> ---
> .../devicetree/bindings/media/i2c/onnn,mt9m114.yaml | 6 ++++++
> 1 file changed, 6 insertions(+)
>
> diff --git a/Documentation/devicetree/bindings/media/i2c/onnn,mt9m114.yaml b/Documentation/devicetree/bindings/media/i2c/onnn,mt9m114.yaml
> index 72e258d57186..666afe10c538 100644
> --- a/Documentation/devicetree/bindings/media/i2c/onnn,mt9m114.yaml
> +++ b/Documentation/devicetree/bindings/media/i2c/onnn,mt9m114.yaml
> @@ -74,6 +74,12 @@ properties:
> description: Bypass the internal PLL of the sensor to use EXTCLK directly as SYSCLK.
> type: boolean
>
> + onnn,slew-rate:
> + $ref: /schemas/types.yaml#/definitions/uint8

No need to make this 8-bit (i.e. just use 32 bits).

> + description: Slew rate ot the output pads DOUT[7:0], LINE_VALID, FRAME_VALID and PIXCLK

Please wrap at 80 characters.

Is there more information on the effect than 7 is the fastest?

> + minimum: 0
> + maximum: 7

Please also add a default.

> +
> required:
> - compatible
> - reg

--
Regards,

Sakari Ailus