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

From: Noralf TrÃnnes
Date: Sat May 19 2018 - 08:41:50 EST



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>;
+ };