xref: /OK3568_Linux_fs/kernel/Documentation/devicetree/bindings/input/touchscreen/fsl-mx25-tcq.txt (revision 4882a59341e53eb6f0b4789bf948001014eff981)
1*4882a593SmuzhiyunFreescale mx25 TS conversion queue module
2*4882a593Smuzhiyun
3*4882a593Smuzhiyunmx25 touchscreen conversion queue module which controls the ADC unit of the
4*4882a593Smuzhiyunmx25 for attached touchscreens.
5*4882a593Smuzhiyun
6*4882a593SmuzhiyunRequired properties:
7*4882a593Smuzhiyun - compatible: Should be "fsl,imx25-tcq".
8*4882a593Smuzhiyun - reg: Memory range of the device.
9*4882a593Smuzhiyun - interrupts: Should be the interrupt number associated with this module within
10*4882a593Smuzhiyun   the tscadc unit (<0>).
11*4882a593Smuzhiyun - fsl,wires: Should be '<4>' or '<5>'
12*4882a593Smuzhiyun
13*4882a593SmuzhiyunOptional properties:
14*4882a593Smuzhiyun - fsl,pen-debounce-ns: Pen debounce time in nanoseconds.
15*4882a593Smuzhiyun - fsl,pen-threshold: Pen-down threshold for the touchscreen. This is a value
16*4882a593Smuzhiyun   between 1 and 4096. It is the ratio between the internal reference voltage
17*4882a593Smuzhiyun   and the measured voltage after the plate was precharged. Resistance between
18*4882a593Smuzhiyun   plates and therefore the voltage decreases with pressure so that a smaller
19*4882a593Smuzhiyun   value is equivalent to a higher pressure.
20*4882a593Smuzhiyun - fsl,settling-time-ns: Settling time in nanoseconds. The settling time is before
21*4882a593Smuzhiyun   the actual touch detection to wait for an even charge distribution in the
22*4882a593Smuzhiyun   plate.
23*4882a593Smuzhiyun
24*4882a593SmuzhiyunThis device includes two conversion queues which can be added as subnodes.
25*4882a593SmuzhiyunThe first queue is for the touchscreen, the second for general purpose ADC.
26*4882a593Smuzhiyun
27*4882a593SmuzhiyunExample:
28*4882a593Smuzhiyun	tsc: tcq@50030400 {
29*4882a593Smuzhiyun		compatible = "fsl,imx25-tcq";
30*4882a593Smuzhiyun		reg = <0x50030400 0x60>;
31*4882a593Smuzhiyun		interrupt-parent = <&tscadc>;
32*4882a593Smuzhiyun		interrupts = <0>;
33*4882a593Smuzhiyun		fsl,wires = <4>;
34*4882a593Smuzhiyun	};
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