This is the touchscreen conversion queue binding documentation. It uses
the shared imx25 ADC.
Signed-off-by: Markus Pargmann <m...@pengutronix.de>
---
Notes:
Changes in v9:
- Updated binding descriptions
Changes in v5:
- Fix signed/unsigned comparison
- Fix unused variable settling_time by putting it in the correct argument
list
- Use continous conversion queue with the repeat feature and a proper
repeat-wait. Previously the touchscreen caused massive number of
interrupts.
.../bindings/input/touchscreen/fsl-mx25-tcq.txt | 35 ++++++++++++++++++++++
1 file changed, 35 insertions(+)
create mode 100644
Documentation/devicetree/bindings/input/touchscreen/fsl-mx25-tcq.txt
diff --git
a/Documentation/devicetree/bindings/input/touchscreen/fsl-mx25-tcq.txt
b/Documentation/devicetree/bindings/input/touchscreen/fsl-mx25-tcq.txt
new file mode 100644
index 000000000000..cdf05f9b2329
--- /dev/null
+++ b/Documentation/devicetree/bindings/input/touchscreen/fsl-mx25-tcq.txt
@@ -0,0 +1,35 @@
+Freescale mx25 TS conversion queue module
+
+mx25 touchscreen conversion queue module which controls the ADC unit of the
+mx25 for attached touchscreens.
+
+Required properties:
+ - compatible: Should be "fsl,imx25-tcq".
+ - reg: Memory range of the device.
+ - interrupts: Should be the interrupt number associated with this module
within
+ the tscadc unit (<0>).
+ - interrupt-parent: Should be a phandle to the tscadc unit.
+ - fsl,wires: Should be '<4>' or '<5>'
+
+Optional properties:
+ - fsl,pen-debounce-ns: Pen debounce time in nanoseconds.
+ - fsl,pen-threshold: Pen-down threshold for the touchscreen. This is a value
+ between 1 and 4096. It is the ratio between the internal reference voltage
+ and the measured voltage after the plate was precharged. Resistence between
+ plates and therefore the voltage decreases with pressure so that a smaller
+ value is equivalent to a higher pressure.
+ - fsl,settling-time-ns: Settling time in nanoseconds. The settling time is
before
+ the actual touch detection to wait for an even charge distribution in the
+ plate.
+
+This device includes two conversion queues which can be added as subnodes.
+The first queue is for the touchscreen, the second for general purpose ADC.
+
+Example:
+ tsc: tcq@50030400 {
+ compatible = "fsl,imx25-tcq";
+ reg = <0x50030400 0x60>;
+ interrupt-parent = <&tscadc>;
+ interrupts = <0>;
+ fsl,wires = <4>;
+ };
--
2.6.2
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