Re: [PATCH 2/3] dt-bindings: new binding for Ilitek ILI9341 display panels

[Noralf TrÃnnes]

Den 15.05.2018 03.43, skrev David Lechner:
> This adds a new binding for Ilitek ILI9341 display panels. It includes
> a compatible string for one display (more can be added in the future).
>
> The vendor prefix "noname" is used because the vendor is not known.
> The YX240QV29-T panel[1] is found, for example, in an Adafruit breakout
> board[2] and in Mindsensors' PiStorms[3].
>
> [1]: https://cdn-learn.adafruit.com/assets/assets/000/046/879/original/SPEC-YX240QV29-T_Rev.A__1_.pdf
> [2]: https://www.adafruit.com/product/2478
> [3]: http://www.mindsensors.com/stem-with-robotics/13-pistorms-v2-base-kit-raspberry-pi-brain-for-lego-robot
>
> Signed-off-by: David Lechner <david@xxxxxxxxxxxxxx>
> ---
>   .../bindings/display/ilitek,ili9341.txt       | 27 +++++++++++++++++++
>   1 file changed, 27 insertions(+)
>   create mode 100644 Documentation/devicetree/bindings/display/ilitek,ili9341.txt
>
> diff --git a/Documentation/devicetree/bindings/display/ilitek,ili9341.txt b/Documentation/devicetree/bindings/display/ilitek,ili9341.txt
> new file mode 100644
> index 000000000000..0fc90b2dd732
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/display/ilitek,ili9341.txt
> @@ -0,0 +1,27 @@
> +Ilitek ILI9341 display panels
> +
> +This binding is for display panels using an Ilitek ILI9341 controller in SPI
> +mode.
> +
> +Required properties:
> +- compatible:	"noname,yx240qv29", "ilitek,ili9341"

Calling a vendor 'noname' looks a bit odd and AFAICT it isn't used by
any other binding. A google search always mentions Adafruit in
connection with this panel, so I suggest we use Adafruit as vendor.

I don't think we should use "ilitek,ili9341" as an option/fallback,
because panels varies in resolution (rarely) and initialization. A
generic ili9341 driver would probably not work with a random new panel.

> +- dc-gpios:	D/C pin
> +- reset-gpios:	Reset pin
> +
> +The node for this driver must be a child node of a SPI controller, hence
> +all mandatory properties described in ../spi/spi-bus.txt must be specified.
> +
> +Optional properties:
> +- rotation:	panel rotation in degrees counter clockwise (0,90,180,270)
> +- backlight:	phandle of the backlight device attached to the panel

You forgot to mention the regulator that you support in the driver.

Noralf.

> +
> +Example:
> +	display@0{
> +		compatible = "noname,yx240qv29", "ilitek,ili9341";
> +		reg = <0>;
> +		spi-max-frequency = <32000000>;
> +		dc-gpios = <&gpio0 9 GPIO_ACTIVE_HIGH>;
> +		reset-gpios = <&gpio0 8 GPIO_ACTIVE_HIGH>;
> +		rotation = <270>;
> +		backlight = <&backlight>;
> +	};