[PATCH 3/4] Input: atmel_mxt_ts: define a device tree binding

[Stephen Warren <swarren@wwwdotorg.org>]

From: Stephen Warren <swarren@nvidia.com>

This document describes how to represent an Atmel MXT touchpad in device
tree.

The device may show up in bootloader mode if reset by SW, or if
configuration/firmware is missing. Or, it may present itself as the final
touchpad device. These modes have different I2C addresses, and hence
different I2C nodes with different compatible values representing their
feature-set.

Cc: Rob Herring <robh+dt@kernel.org>
Cc: Pawel Moll <pawel.moll@arm.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Ian Campbell <ijc+devicetree@hellion.org.uk>
Cc: Kumar Gala <galak@codeaurora.org>
Cc: devicetree@vger.kernel.org
Signed-off-by: Stephen Warren <swarren@nvidia.com>
---
 .../devicetree/bindings/input/atmel,mxt-tp.txt     | 26 ++++++++++++++++++++++
 1 file changed, 26 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/input/atmel,mxt-tp.txt

diff --git a/Documentation/devicetree/bindings/input/atmel,mxt-tp.txt b/Documentation/devicetree/bindings/input/atmel,mxt-tp.txt
new file mode 100644
index 000000000000..c62798ef3a82
--- /dev/null
+++ b/Documentation/devicetree/bindings/input/atmel,mxt-tp.txt
@@ -0,0 +1,26 @@
+Atmel MXT touchpad
+
+Required properties:
+- compatible: One of:
+    atmel,mxt-tp (for the main touchpad I2C address)
+    atmel,mxt-tp-bootloader (for the bootloader I2C address)
+
+- reg: The I2C address of the device
+
+- interrupts: The sink for the touchpad's IRQ output
+    See ../interrupt-controller/interrupts.txt
+
+Optional properties for main touchpad device:
+
+- linux,gpio-keymap: An array of up to 4 entries indicating the Linux
+    keycode generated by each GPIO. Linux keycodes are defined in
+    <dt-bindings/input/input.h>.
+
+Example:
+
+	trackpad@4b {
+		compatible = "atmel,mxt-tp";
+		reg = <0x4b>;
+		interrupt-parent = <&gpio>;
+		interrupts = <TEGRA_GPIO(W, 3) GPIO_ACTIVE_HIGH>;
+	};
-- 
1.8.1.5