Re: [PATCH v3 1/4] media: dt-bindings: media: i2c: Switch to assigned-clock-rates

From: Laurent Pinchart
Date: Fri Mar 13 2020 - 17:20:20 EST


Hi Prabhakar,

Thank you for the patch.

On Fri, Mar 13, 2020 at 09:12:31PM +0000, Lad Prabhakar wrote:
> Use assigned-clock-rates to specify the clock rate. Also mark
> clock-frequency property as deprecated.

I would phrase it the other way around, this patch mainly deprecates
clock-frequency, and as a side effect recommends usage of
assigned-clock-rates.

"Deprecate usage of the clock-frequency propertly. The preferred method
to set clock rates is to use assigned-clock-rates."

> Signed-off-by: Lad Prabhakar <prabhakar.mahadev-lad.rj@xxxxxxxxxxxxxx>
> ---
> Documentation/devicetree/bindings/media/i2c/ov5645.txt | 5 +++--
> 1 file changed, 3 insertions(+), 2 deletions(-)
>
> diff --git a/Documentation/devicetree/bindings/media/i2c/ov5645.txt b/Documentation/devicetree/bindings/media/i2c/ov5645.txt
> index 72ad992..e62fe82 100644
> --- a/Documentation/devicetree/bindings/media/i2c/ov5645.txt
> +++ b/Documentation/devicetree/bindings/media/i2c/ov5645.txt
> @@ -8,7 +8,7 @@ Required Properties:
> - compatible: Value should be "ovti,ov5645".
> - clocks: Reference to the xclk clock.
> - clock-names: Should be "xclk".
> -- clock-frequency: Frequency of the xclk clock.
> +- clock-frequency (deprecated): Frequency of the xclk clock.

I would drop this completely. Drivers need to ensure backward
compatibility, but DT bindings should only document the latest version,
the history is available in git.

Reviewed-by: Laurent Pinchart <laurent.pinchart@xxxxxxxxxxxxxxxx>

While at it, can I enlist you to convert these bindings to yaml ? :-)

> - enable-gpios: Chip enable GPIO. Polarity is GPIO_ACTIVE_HIGH. This corresponds
> to the hardware pin PWDNB which is physically active low.
> - reset-gpios: Chip reset GPIO. Polarity is GPIO_ACTIVE_LOW. This corresponds to
> @@ -37,7 +37,8 @@ Example:
>
> clocks = <&clks 200>;
> clock-names = "xclk";
> - clock-frequency = <24000000>;
> + assigned-clocks = <&clks 200>;
> + assigned-clock-rates = <24000000>;
>
> vdddo-supply = <&camera_dovdd_1v8>;
> vdda-supply = <&camera_avdd_2v8>;

--
Regards,

Laurent Pinchart