dt-bindings: Add binding for Ilitek ILI9225 display panels

This adds a new binding for display panels that use an Ilitek ILI9225
controller.

The "ilitek,ili9225-2.2in-176x220" device listed has no identification
markings whatsoever and an hour of googling turned up nothing, hence the use
of the size and resolution in the name instead of a model name.

An example of this nameless device can be found at:
https://github.com/Nkawu/TFT_22_ILI9225

Signed-off-by: David Lechner <david@lechnology.com>
Acked-by: Rob Herring <robh@kernel.org>
Signed-off-by: Noralf Trønnes <noralf@tronnes.org>
Link: https://patchwork.freedesktop.org/patch/msgid/1511122328-31133-3-git-send-email-david@lechnology.com

diff --git a/Documentation/devicetree/bindings/display/ilitek,ili9225.txt b/Documentation/devicetree/bindings/display/ilitek,ili9225.txt
new file mode 100644 (file)
index 0000000..21607a5
--- /dev/null
+++ b/Documentation/devicetree/bindings/display/ilitek,ili9225.txt
@@ -0,0 +1,25 @@
+Ilitek ILI9225 display panels
+
+This binding is for display panels using an Ilitek ILI9225 controller in SPI
+mode.
+
+Required properties:
+- compatible:  "ilitek,ili9225-2.2in-176x220"
+- rs-gpios:    Register select signal
+- 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)
+
+Example:
+       display@0{
+               compatible = "ilitek,ili9225-2.2in-176x220";
+               reg = <0>;
+               spi-max-frequency = <12000000>;
+               rs-gpios = <&gpio0 9 GPIO_ACTIVE_HIGH>;
+               reset-gpios = <&gpio0 8 GPIO_ACTIVE_HIGH>;
+               rotation = <270>;
+       };